D5
. svedoliver/iStock/Thinkstock Learning Objectives After studying this chapter, you should be able to: • Name the six main criteria air pollutants as defined by the Environmental Protection Agency, and describe the difference between primary and secondary air pollutants. • Define water pollution and discuss the difference between point source and non-point source water pollution. • Describe the various uses of the common chemical compounds bisphenol A, phthalates, and polybro- minated diphenyl ethers and why scientists are growing increasingly concerned over prolonged human exposure to these chemicals. • Explain the difference between non-municipal and municipal solid waste (MSW) and discuss ways in which MSW is managed and disposed of in order to minimize environmental impacts. • Explain how life-cycle analysis—an evaluation of the overall environmental impact of a product or process—can be used to determine the relative environmental impacts of recycling aluminum, glass, plastic, and paper relative to simply disposing of these products. Pollution and Waste Management 9 ben85927_09_c09.indd 365 1/28/14 1:19 PM INtro Duct IoN Pre-Test 1. Factors such as temperature, humidity, and air movement make it easier to analyze and measure air pollution. a. t rue b. False 2. Low levels of dissolved oxygen can revitalize fish and shellfish. a. t rue b. False 3. Bisphenol A (BPA) is an example of a hormone-mimicking compound. a. t rue b. False 4. t he most common form of waste in the municipal solid waste stream in the united States is a. plastic. b. disposable diapers. c. food waste. d. paper. 5. It takes 96 percent less energy to make an aluminum can from recycled materials than it does to process it from new materials. a. t rue b. False Answers 1. b. False. the answer can be found in section 9.1. 2. b. False. the answer can be found in section 9.2. 3. a. t rue. the answer can be found in section 9.3. 4. d. paper. the answer can be found in section 9.4. 5. a. t rue. the answer can be found in section 9.5. Introduction In 2009, Americans consumed 8.6 billion gallons of bottled water, approximately doubling the consumption of 2000. Much of this total quantity was sold in convenient, throwaway pint bottles that were discarded at the rate of about 50 million water bottles per day or close to 20 billion per year. If you add soda, coffee, and other beverages, Americans discarded 250 bil - lion one-use beverage containers a year in 2010, roughly 3 per person per day (Gleick, 2010).
Beverage containers represent just the tip of the iceberg, however, as just about everything you see will end up in the trash sooner or later. this fact causes concern among scientists, environmentalists, and communities who recognize that the world has a growing trash prob - lem. Indeed, between the mass quantities of solid waste that is piling up in landfills and burned in incinerators and transportation emissions, pollutants are seeping into our water and getting carried on the wind at an alarming rate. ben85927_09_c09.indd 366 1/28/14 1:19 PM INtro Duct IoN Even today, with all that we know about the negative effects of polluting our environment with chemicals and solid waste, many materials are discarded haphazardly along our road- ways and beaches, or dumped into rivers that wash into the oceans. Slurries of weathered and eroded plastics float about in the oceans and enter the food chain, accumulating in the guts of plankton and the stomachs of fish and marine mammals. About 64 percent of municipal solid waste is simply buried in landfills while toxic substances seep into the soil and groundwater.
And even though experts disagree about how to cut down on pollution and manage waste, most agree that the status quo for dealing with these issues is not sufficient. thus, in this chapter we will investigate how the life cycle of products—from production to disposal— impacts air and water quality. We will also discuss issues and politics regarding solid and hazardous waste management as we explore options for the future.
A few concepts are worth establishing before we jump into the readings for this chapter. First, it sometimes helps to think of pollution and waste moving or being transported from a source to a sink. For example, if we want to study the environmental impact of nutrient runoff from farms in the Midwest (the source) on water quality in the Gulf of Mexico (the sink), we need to first identify the sources of nutrient pollution. We need to understand how this nutrient pollution is mobilized and transported hundreds or thousands of miles to the Gulf of Mexico.
We also need to determine where it settles and how it impacts wildlife, humans, and ecologi - cal systems in that location. the same steps hold true for the study of air pollution or flows of solid and hazardous wastes into and through the environment.
A second important concept to consider is how human production, consumption, and waste disposal systems differ from what we find in the natural world. It is said that in nature there is no such thing as waste or that all waste = food. For example, consider a few simple interactions between an herbivore such as a white-tailed deer and plants in a forest ecosystem. the deer might browse on tree seedlings, wildflowers, and other plants and release the waste prod- ucts feces, urine, and even carbon dioxide as it exhales. the feces and urine contain nutrients (such as nitrogen and phosphorous) that can be taken up and reused by the plants. Likewise, the plants need carbon dioxide in order to photosynthesize, in turn releasing oxygen that can be thought of as a waste product of photosynthesis. the oxygen and new plant growth is available again for the deer in an ongoing cycle. In this sense we can say that ecosystems tend to be characterized by cyclical flows of matter and nutrients and powered by inputs of solar energy from the sun.
In contrast, modern human systems of manufacturing, food production, and waste manage- ment tend to be highly linear. We extract material from the ground, process it, manufacture something, use that, and then dispose of it in landfills. For example, an aluminum can is made from bauxite ore mined from the ground, processed or refined in an energy-intensive pro - cess to be converted to alumina, transformed into aluminum, and then manufactured into cans and filled with beverages. roughly half of the beverage-filled aluminum cans sold in the united States are used once and then disposed of in the garbage. Such a linear system requires us to keep returning to extract more raw material from the Earth and generates unnecessary and often toxic/hazardous waste throughout the product life cycle. Even our modern agricul - tural systems are dependent on linear production processes, a characteristic that makes them unsustainable in the long run (see chapter 3). ben85927_09_c09.indd 367 1/28/14 1:19 PM SEct IoN 9.1 AIr Po LLut IoN A major challenge then is to find ways to “close the loop” or shift manufacturing, agricultural, and other production systems from a linear to a cyclical process. We can look to natural sys- tems for insight and ideas on how to do this since it is clear that these systems are productive (think of the wood, water, wildlife, and recreation opportunities “produced” by a forest) with - out any external inputs and with virtually zero waste production. As you work through this chapter, focus not only on the problems of pollution and waste management but also on how we might create systems that don’t even produce waste in the first place.
9.1 Air Pollution The U.S. Environmental Protection Agency (EPA) sets standards for six major categories of air pollutants (known as criteria air pollutants): carbon monoxide (CO), lead (Pb), nitrogen diox - ide (NO 2), ozone (O 3), particulate matter (PM), and sulfur dioxide (SO 2). These pollutants come from a variety of sources, both stationary (such as a coal-fired power plant) and mobile (such as cars and trucks). Each type of pollutant negatively impacts human and ecosystem health with varying levels of severity.
Understanding the link between air pollution and human health can be very challenging; sci - entists attempt to study this relationship, called the source-receptor relationship, through a variety of techniques. But because people are exposed to air pollution in so many different ways, it is almost impossible to link any one disease or illness to a specific source of pollution. Never - theless, scientists are certain that prolonged exposure to criteria air pollutants can be linked to many preventable illnesses and deaths, and that efforts to reduce these pollutants really do save lives .
Environmental scientists typically break air pollution down into two major categories. Primary air pollutants are those that are emitted directly into the atmosphere, such as particulate mat - ter and sulfur dioxide emitted from burning coal in a power plant. Secondary air pollutants are formed through chemical reactions in the atmosphere, oftentimes between primary (or pre - cursor) pollutants, and they are typically more difficult to control than primary. For example, ground-level ozone forms as a result of reactions between nitrogen oxides (NO x—mostly from cars and trucks) and volatile organic compounds (VOCs—such as gasoline vapors or solvents) in the presence of sunlight. That is why some of the worst ozone pollution episodes occur during hot summer days in and around major metropolitan areas. Such episodes require that sensitive groups (most often infants, the elderly, and people with respiratory problems) stay indoors until safe ozone levels return with cooler temperatures.
In the following overview of air pollution science prepared by the National Research Council— Committee on Air Quality Management in the United States, we learn just how complicated it is to determine where air pollution originates, how it moves, and the ways in which it impacts human health and natural systems. The complexities involved make it a challenge for govern - ments to regulate and control air pollution. However, substantial improvements have been made due to the implementation in the United States of regulations such as the Clean Air Act (CAA).
Indeed, the EPA estimates that the law and its amendments may prevent up to 230,000 early deaths by the year 2020 . ben85927_09_c09.indd 368 1/28/14 1:19 PM SEct IoN 9.1 AIr Po LLut IoN By the Committee on Air Quality Management in the United States, National Research Council Air Pollution Science the atmosphere is composed of a mixture of gases and particles. An air pollutant is gen - erally defined as any substance in air that, in high enough concentrations, harms humans, ecosystems (other animals and vegetation), or materials (such as buildings and monuments) and reduces visibility. In this report, the committee uses the term air pollutant to denote the subset of harmful atmospheric substances that are present, at least in part, because of human activities rather than natural production and whose principal deleterious effects occur as a result of exposure at ground level. the science of air pollution is primarily concerned with quantitatively understanding the so- called “source-receptor relationships” [the science of understanding how air pollutants move from the emission source to where they end up or deposit and the effects they have on people or other organisms once they end up there] that link specific pollutant emissions to the pol- lutant concentrations and deposition observed in the environment as a function of space and time. this quantitative understanding is developed through extensive field and laboratory measurements and analysis and is then tested and documented in air quality models that use mathematical and numerical techniques to simulate the physical and chemical processes that affect air pollutants as they disperse and react in the atmosphere. [. . .] Scientists try to understand how air pollution is formed, where and how it moves, and ways in which it impacts our health and the health of ecosystems. Because air pollution is influ- enced by atmospheric and weather conditions—winds, precipitation, temperature—it is dif- ficult for scientists to run controlled experiments. therefore, they resort to a variety of tech - niques to create situations that mimic real life. Some of these techniques include exposing laboratory animals and plants to air pollutants like ozone; long-term monitoring of people who live and/or work in high-pollution areas; following air pollution movements through the use of sensors; and using mathematical models to try and predict how air pollution moves under different conditions.
Air pollutants are often characterized by how they originate: pollutants emitted directly into the atmosphere are called primary pollutants; those formed as a result of chemical reactions within the atmosphere are called secondary pol- lutants. control of secondary pollutants is generally more problematic than that of primary pollutants, because mitiga- tion of secondary pollutants requires Consider This Air pollutants have been identified as either primary or secondary. Define the difference between the two and discuss why these designations are important to controlling pollution sources. ben85927_09_c09.indd 369 1/28/14 1:19 PM SEct IoN 9.1 AIr Po LLut IoN identification of the precursor compounds [ these are primary pollutants that combine to create secondary pollutants. For example, nitrogen oxides and volatile organic compounds are primary pollutants, or precursor compounds, that can combine to cause ozone, a second - ary pollutant.] and their sources as well as an understanding of the specific chemical reactions that result in the formation of the secondary pollutants. control can be further complicated when the chemical reactions resulting in secondary-pollutant formation involve complex, nonlinear interactions [a relationship between two things, in this case air pollutants, that is not on a one-to-one basis. For example, primary pollutants can increase 20% and result in a 50% increase in secondary pollutants] among the precursors. under those conditions, a 1:1 relationship might not exist between a reduction in precursor emissions and reduc - tions in secondary-pollutant concentrations. Ground-level o3 [ozone] is an example of such a secondary pollutant; it is formed by reactions of nitrogen oxides (N ox) and volatile organic compound (V oc ) species in the presence of sunlight. In some circumstances, o3 concentra- tions are most effectively controlled by lowering both V oc and N ox emissions. For other cir- cumstances, lowering V oc or N ox emissions may be most effective Nitric oxide (N o) and nitrogen dioxide (N o2 ) are referred to together as N ox. V oc s are organic compounds present in the gas phase at ambient conditions. Several other terms are used operationally to refer to and classify organic compounds. For example, reactive V oc s are sometimes designated as reactive organic gases ( ro G); however, because hydrocarbons make up most of the organic gas emissions, this category is also called reactive hydrocarbons (rHc). Moreover, because methane dominates the unreactive category, the term nonmethane hydrocarbons (or NMH c) is often used. unless noted otherwise, V oc s will be used in this report to represent the general class of gaseous organic compounds.
Similar complications arise in the mitigation of suspended particulate matter (PM), which refers to a heterogeneous [composed of different substances, or the same substances, but in different states, such as ice and water] collection of solid and liquid particles that include ultrafine particles (diameters of less than 0.1 micrometers [mm]); fine particles (diameters of 0.1 to a few micrometers), which are commonly dominated by sulfate, nitrate, organic, and metal components; and relatively coarse particles (diameters of a few micrometers or more), which are often dominated by dust and sea salt. PM can be a primary or secondary pollutant.
As a primary pollutant, PM is emitted directly to the atmosphere, for instance, as a result of fossil fuel combustion. As a secondary pollutant, PM is formed in the atmosphere as a result of such processes as oxidation of sulfur dioxide (S o2 ) gas to form sulfate particles. Because the reactions that result in the formation of secondary PM often depend on the concentration and composition of preexisting airborne PM, control strategies that lower the emissions of one chemical constituent of airborne PM might not affect or might in some cases increase the con - centrations of other components of PM. Even though pollutants have been typically treated independently in many of the air quality regulations in the united States, pollutants are often closely coupled [linked]. For example, most pollutants are emitted into the atmosphere by the same source types. ben85927_09_c09.indd 370 1/28/14 1:19 PM SEct IoN 9.1 AIr Po LLut IoN Figure 9.1: Sources of air pollution the national average emission categories for carbon monoxide ( co ), sulfur dioxide (S o2), nitric oxide and nitrogen dioxide (N oX), volatile organic compounds (V oc s), particulate matter less than 10 micrometers in diameter (PM 10), and particulate matter less than 2.5 micrometers in diameter (PM 2.5) for 2012. As the pie charts show, pollutants are emitted into the atmosphere from the same source types. Data from: http://www.epa.gov/ttn/chief/trends/index.html CO Emission Percentage Stationary Fuel Combustion Industrial Processes Transportation Miscellaneous 7%5% 34% 54% NO X Emission Percentage Stationary Fuel Combustion Industrial Processes Transportation Miscellaneous2% 10 % 33% 55% VOC Emission Percentage Stationary Fuel Combustion Industrial Processes Transportation Miscellaneous 4% 44% 22% 30% Primary PM 10 Emission Percentage Stationary Fuel Combustion Industrial Processes Transportation Miscellaneous 7%2% 5% 86% Primary PM 2.5 Emission Percentage Stationary Fuel Combustion Industrial Processes Transportation Miscellaneous 12% 69% 5% 14% SO 2 Emission Percentage Stationary Fuel Combustion Industrial Processes Transportation Miscellaneous 11 % 82% 2% 5% ben85927_09_c09.indd 371 1/28/14 1:19 PM SEct IoN 9.1 AIr Po LLut IoN they also often share similar precursors and similar chemical interactions once in the atmo - sphere. For example, many of the V oc s that react to form o3 are also identified as hazardous air pollutants (HAPs). V oc s and HAPs can also be precursors to or components of PM. In a similar manner, N ox has several significant environmental effects that warrant its control. In addition to being an o3 precursor, it has a direct impact on human health, is a precursor for acid rain and the formation of inhalable fine particles, decreases atmospheric visibility, and contributes to the eutrophication of water bodies.
Air pollution, especially in more urban and industrialized areas, is sometimes referred to as “soup.” Like soup, air pollution is usually made up of different ingredients, and if you com- bine various ingredients in different quantities you will get a very different result each time you make it. Indeed, air pollutants originate from so many different sources in countless combinations under changing atmospheric and weather conditions. this makes it difficult to study, regulate, and control air pollution and understand how it affects both human and ecosystem health.
Figure 9.2: Sources of air pollution, primary and secondary pollutants Forest fires, cars, factories, and homes are some sources of air pollution that contribute to primary and secondary air pollutants. Interactions between these pollutants can lead to harmful environmental effects such as acid rain. Natural Sources Mobile SourcesStationary Sources 2. Primary air pollutants interact and create secondary air pollutants such as O 3, SO 3, and HNO 3. 1. Different sources emit primary air pollutants that include CO, NO x, SO 2, and PM. ben85927_09_c09.indd 372 1/28/14 1:19 PM SEct IoN 9.1 AIr Po LLut IoN Air Pollution Impacts the primary objective of most air qual - ity standards in the united States is the protection of human health. Humans are exposed to air pollution outdoors and indoors, including during transit in vehi- cles. Indoor air pollution comprises a mix - ture of contaminants penetrating from outdoors and those generated indoors.
Especially high exposure to air pollution can also occur in various microenvironments, referred to here as “hot spots,” which include highway toll plazas; truck stops; airport aprons; and areas adjacent to industrial facilities, busy roadways, and idling vehicles. Some studies have suggested that disproportionate exposures may be found in low-income and predominantly minority communities and have raised con - cerns about environmental justice.
Many types of health effects have been attributed to air pollution, including pulmonary, car - diac, vascular, and neurological impairments—all of which can lead directly to mortality. In addition, a number of regulated air pollutants are known or probable carcinogens. Some health effects, such as an increase in asthma attacks, have been observed in conjunction with episodes of high pollution concentrations lasting 1 or 2 days. Such effects are considered acute, because they are associated with short-term exposures to a pollutant. other health effects, particularly increased risk of cancer, are associated with long-term exposure.
the scientific techniques for assessing health impacts of air pollution include air pollutant monitoring, exposure assessment, dosimetry [techniques for measuring an individual’s expo - sure to hazardous compounds in the environment, typically over a long period of time], toxi - cology, and epidemiology. Because most of the health effects attributable to air pollutants can also be attributable to a wide variety of other risk factors, the impact of air pollution on human health can be difficult to distinguish and quantify. Determining the impact of air pollu - tion on human health is further complicated by human exposure to a mixture of substances at various concentrations present in the air. Also, a number of subgroups within the human pop - ulation at large are considered more susceptible to the effects of air pollution. they include people who have coronary disease, asthma, or chronic pulmonary diseases; the elderly; and infants. Fetuses are also possibly susceptible.
In addition to air pollution effects on human health, impacts on ecosystem form and function are also a serious concern. Moreover, because ecosystems often supply society with valuable services (such as cleaning and purifying water), damage to ecosystems from air pollution can exact a significant economic as well as an environmental cost. terrestrial [land], aquatic, and coastal ecosystems are exposed to air pollution via atmospheric substances (such as o3), or by deposition of substances (such as acids, nutrients, and metals). In terrestrial ecosystems, air pollution deposition affects plant physiology; microbial processes; biogeochemical cycles of substances, such as nitrogen; and plant community dynamics. In aquatic ecosystems, acidic deposition results in acidification of waterways, the mobilization of trace metals in surface waters, and ultimately, the loss of aquatic biodiversity. Atmospheric deposition is also a major source of mercury to some aquatic ecosystems in North America. When mercury is present as methylmercury in sufficient quantities in the food chain, this contaminant is toxic to humans and animals. In addition, atmospheric deposition of nitrate and ammonium might be an important source of nitrogen in coastal regions, contributing to eutrophication, increased or Consider This What is it about the way that air pollution is formed and transported that makes it challenging to study using “controlled” experiments? How do scientists get around these challenges? ben85927_09_c09.indd 373 1/28/14 1:19 PM SEct IoN 9.1 AIr Po LLut IoN harmful algal blooms, hypoxic [low oxy- gen levels] and anoxic [severe hypoxia] bottom waters, loss of sea grasses, and reduced fish stocks.
Protection of visibility in national parks and wilderness areas has traditionally played a smaller but nonetheless impor - tant role in driving air quality regulation.
Scenic vistas in most u.S. parklands are often diminished by haze that reduces contrast, washes out colors, and renders distant landscape features indistinct or invisible. Haze degrades visibility pri- marily through scattering or absorption of light by fine atmospheric particles.
Air pollution can discolor or damage com- monly used building materials and works of art. In addition, such pollutants as sul - fate can accelerate the natural weather - ing process of materials, including metals, painted surfaces, stone, and concrete. Air Quality Management in the United States As the health, ecological, and economic impacts of air pollution in the united States have become increasingly evident through more sophisticated scientific approaches, the nation has endeavored to protect air quality through increasingly complex and ambitious legisla - tion. the federal government’s first major efforts in this regard began in 1955 with the Air Pollution Control Act . these efforts were enhanced over the next 15 years through a series of enactments, including the clean Air Act ( cAA) of 1963. In 1970, two landmark events took place that helped to establish the basic framework by which air quality is managed in the united States. these events were the creation of the u.S. Environmental Protection Agency (EPA) and the passage of the cAA Amendments of 1970. this framework was further devel - oped and refined with the passage of the cAA Amendments of 1977 and 1990. Five major goals for protecting and promoting human health and public welfare are identified in the cAA as amended: • Mitigating potentially harmful human and ecosystem exposure to six criteria pollut - ants: co , N o2, So2, o3, PM, and lead (Pb). • Limiting the sources of and risks from exposure to HAPs, which are also called air toxics. • Protecting and improving visibility impairment in wilderness areas and national parks. • reducing the emissions of species that cause acid rain, specifically S o2 and N ox. • curbing the use of chemicals that have the potential to deplete the stratospheric o3 layer. Consider This When we think of air pollution, we usually think of it as an outdoor problem. How - ever, environmental scientists are increas- ingly concerned about something known as indoor air pollution—pollution pro- duced by products and processes found inside a home or building. review these two sources of information provided by the Environmental Protection Agency (EPA) to try to determine what indoor air pollution hazards you might be exposed to and what you can do about it:
• http://www.epa.gov/iaq/ia-intro .html • http://www.epa.gov/iaq/ ben85927_09_c09.indd 374 1/28/14 1:19 PM SEct IoN 9.1 AIr Po LLut IoN the cAA prescribes a complicated set of responsibilities and relationships among federal, state, tribal, and local agencies. this matrix is referred to in this report as the nation’s air quality management (AQM) system. the federal government’s role is coordinated by EPA and is intended in part to provide a degree of national uniformity in air quality standards and approaches to pollution mitigation so that all individuals in America are assured a basic level of environmental protection. State and local governments are given much of the responsi- bility for implementing and enforcing the federally mandated rules and regulations within their jurisdictional domains, including developing and implementing specific strategies and control measures to meet national air quality standards and goals. Although many aspects of the AQM system assume a collaborative relationship between the federal, state, and local agencies, the cAA empowers EPA to oversee the activities carried out by those agencies. this oversight includes the power to impose federal sanctions and federally devised pollution- control plans on delinquent areas in some cases.
The Role of Science Although an understanding of the causes and remedies of air pollution is not yet complete, it is now well-established that the vast majority of the air pollutants addressed by the cAA arise from the burning of fossil fuels and the emission of the myriad of materials and chemi - cals produced and used in the commerce of this country. However, for a number of broader societal and technical reasons, a total termination of the nation’s dependence on fossil fuels and the products and industrial processes that result in pollutant emissions is not a viable option. Indeed, the substantial disruption likely to result could conceivably cause greater damage to human health and welfare than that caused by air pollution in the united States. A more viable option, and the one our society uses, is to control air pollutants at concentra- tions that pose a minimal or acceptable level of risk to human health and welfare without unduly disrupting the technological infrastructure and economic engine that underpins the nation’s economy. to accomplish such control, science and technology are required. their roles include the following: 1. Quantifying risks to human health and public welfare (such as ecosystems) associ - ated with varying concentrations, mixtures, and rates of deposition of air pollutants to establish air quality standards and goals. 2. Quantifying the source-receptor relationships that relate pollutant emission rates to ambient pollutant concentrations and deposition rates in order to develop air pollu - tion mitigation strategies to maximize benefits and minimize costs. 3. Quantifying the expected demographic and economic trends with and without air pollution control strategies to better account for growth in activity that might offset pollution control measures and to better design control strategies that are compat- ible with the economic incentives of those who must implement them. 4. Designing and implementing air quality monitoring technologies and methods for documenting pollutant exposures to identify risks and set priorities. 5. Designing, testing, and implementing technologies and systems for efficiently pre- venting or reducing air pollutant emissions. 6. Designing and implementing methods and technologies for tracking changes in pol- lutant emissions, pollutant concentrations, and human health and welfare outcomes to document and ultimately improve the effectiveness of air pollution mitigation activities. ben85927_09_c09.indd 375 1/28/14 1:19 PM SEct IoN 9.1 AIr Po LLut IoN [. . . t]he aforementioned contributions of science and technology are made through moni - toring, analysis, research, and development. Monitoring provides the data necessary to determine trends in emissions, air quality, and various health and ecosystem outcomes. Such observational data are essential for determining the effectiveness of regulations and assur- ing compliance, providing valuable input to air quality models, and supporting long-term health and ecosystem assessments. In addition, the data are used by the scientific research community. Analysis activities also provide critical information to air quality managers who use model results, risk assessments, and economic and other analyses to better characterize their air quality problems and the impacts of various control strategies. Finally, research and development efforts furnish advances in the fundamental understanding of the science and impacts of air pollution, the instruments needed for monitoring, and the technology available for controlling emissions. thus, at each stage of cAA implementation, science and technology provide a fundamental basis for sound decisions; at the same time, the requirements of the cAA to continually improve air quality and the understanding of it serves as an important incentive to promote scientific and technological advances. [. . .] Adapted from National Research Council 2004. Air Quality Management in the United States. Committee on Air Quality Management in the United States. National Academies Press. Retrieved from http://www.nap.edu/catalog /10728.html Used by permission. Apply Your Knowledge the EPA maintains AI rNow, a web page of local air quality conditions and forecasts. the AIrNow page allows you to view current air quality conditions in your area, forecasts of air quality in the days ahead, and archives of air quality conditions by region. Visit the AI rNow home page (http://www.airnow.gov ) and do the following:
• View the national map of today’s air quality index (AQI) forecast. What regions of the country are showing air quality problems? How bad is AQI predicted to be in these regions? Why might these areas be experiencing poor air quality? • click on your state on the map. What is the air quality forecast for your state? How does it compare to other states? • Lastly, click on one of the cities listed for your state to the right of the state map. on that page there is a link in the table in the lower right called “Air Quality Maps Archives (by region).” click on that link. From the drop down menus along the top, select “AQI Animation” for map type and a city or region near you from the map region menu. Next, select January, 2012 from the month and year menus and click “See Maps.” this will allow you to see animated maps of how air quality changed over the course of each day in that month. Move from January to February and through each month to December 2012 while observing how different air quality conditions were day to day and month to month. What were the worst months of 2012 for air quality in your region? What might be happening during those months to make air quality so bad? Generally speaking, the hotter the weather, the worse the air quality. Why might this be? ben85927_09_c09.indd 376 1/28/14 1:19 PM SEct IoN 9.2 WAtEr Po LLut IoN 9.2 Water Pollution Water pollution can be defined as the contamination of any water body with substances that alter the biological, physical, or chemical properties of that system. Common examples of water pollution include discharge from sewage treatment plants, waste discharge from industrial facilities, soil/sediment erosion, runoff of fertilizers from farms or lawns, and dumping of trash, plastics, or hazardous substances directly into a water body. Increasing water temperature, or thermal pollution, is also considered a form of water pollution and can harm aquatic organ- isms. This commonly happens as a result of water being extracted from a river or other water - way, used for cooling purposes in a power plant or other industrial facility, and then returned to the waterway at a higher temperature.
Scientists typically break water pollution down into two categories: point source and non- point source. Point source water pollution is pollution that comes from a single, identifiable source such as a sewage treatment plant or a discharge pipe from a factory. Non-point source water pollution refers to pollution that enters waterways from dispersed locations, such as rain - water running off a parking lot, picking up contaminants like oil and antifreeze leaked from cars, and flowing into streams and rivers directly. In the 1960s and 1970s, dramatic water pollu - tion episodes such as the Cuyahoga River in Cleveland, Ohio, catching on fire and the declaration of large parts of Lake Erie as “dead” resulted in the establishment of what is now known as the Clean Water Act (CWA) . The CWA has been very effective at regulating and reducing the impact of point source pollution; however, non-point sources of pollution have proven more difficult to regulate and control .
To better understand the connections between water pollution and human and ecological health, scientists with the U.S. Geological Survey (USGS) regularly monitor and draw samples from the nation’s waterways. This information is also useful in studying changes in water qual - ity and condition over time and in designing the best approaches to reduce water pollution. In this article, Joseph Orlins, a civil engineering professor at Rowan University in New Jersey, and Anne Wehrly, an attorney and freelance writer, review the impacts of water pollution, the devel - opment of regulations to control this problem, and future developments in this field .
By Joseph Orlins and Anne Wehrly As water pollution threatens our health and environment, we need to implement an expand - ing array of techniques for its assessment, prevention, and remediation .
In the 1890s, entrepreneur William Love sought to establish a model industrial community in the La Salle district of Niagara Falls, New York. the plan included building a canal that tapped water from the Niagara river for a navigable waterway and a hydroelectric power plant.
Although work on the canal was begun, a nationwide economic depression and other factors forced abandonment of the project.
By 1920, the land adjacent to the canal was sold and used as a landfill for municipal and indus - trial wastes. Later purchased by Hooker chemicals and Plastics corp., the landfill became a dumping ground for nearly 21,000 tons of mixed chemical wastes before being closed and covered over in the early 1950s. Shortly thereafter, the property was acquired by the Niagara Falls Board of Education, and schools and residences were built on and around the site. ben85927_09_c09.indd 377 1/28/14 1:19 PM SEct IoN 9.2 WAtEr Po LLut IoN In the ensuing decades, groundwater levels in the area rose, parts of the landfill subsided, large metal drums of waste were uncovered, and toxic chemicals oozed out. All this led to the contamination of surface waters, oily residues in residential basements, corrosion of sump pumps, and noxious odors. residents began to question if these problems were at the root of an apparent prevalence of birth defects and miscarriages in the neighborhood.
Eventually, in 1978, the area was declared unsafe by the New York State Department of Health, and President Jimmy carter approved emergency federal assistance. the school located on the landfill site was closed and nearby houses were condemned. State and federal agencies worked together to relocate hundreds of residents and contain or destroy the chemical wastes.
that was the bitter story of Love canal. Although not the worst environmental disaster in u.S. history, it illustrates the tragic consequences of water pollution.
Water Quality Standards In addition to toxic chemical wastes, water pollutants occur in many other forms, includ- ing pathogenic microbes (harmful bacteria and viruses), excess fertilizers (containing com - pounds of phosphorus and nitrogen), and trash floating on streams, lakes, and beaches. Water pollution can also take the form of sediment eroded from stream banks, large blooms of algae, low levels of dissolved oxygen, or abnormally high temperatures (from the discharge of cool - ant water at power plants).
the united States has seen a growing concern about water pollution since the middle of the twentieth century, as the public recognized that pollutants were adversely affecting human health and rendering lakes unswimmable, streams unfishable, and rivers flammable. In response, in 1972, congress passed the Federal Water Pollution control Act Amendments, later modified and referred to as the clean Water Act. Its purpose was to “restore and main - tain the chemical, physical, and biological integrity of the nation’s waters.” the clean Water Act set the ambitious national goal of completely eliminating the discharge of pollutants into navigable waters by 1985, as well as the interim goal of making water clean enough to sustain fish and wildlife, while being safe for swimming and boating. to achieve these goals, certain standards for water quality were established.
the “designated uses” of every body of water subject to the act must first be identified. Is it a source for drinking water? Is it used for recreation, such as swimming? Does it supply agriculture or industry? Is it a significant habitat for fish and other aquatic life? thereafter, the water must be tested for pollutants. If it fails to meet the minimum standards for its designated uses, then steps must be taken to limit pollutants entering it, so that it becomes suitable for those uses.
Here, There, and Everywhere Implementing the clean Water Act requires clarifying the sources of pollutants. they are divided into two groups: “point sources” and “nonpoint sources.” Point sources correspond to discrete, identifiable locations from which pollutants are emitted. they include factories, ben85927_09_c09.indd 378 1/28/14 1:19 PM SEct IoN 9.2 WAtEr Po LLut IoN wastewater treatment plants, landfills, and underground storage tanks. Water pollution that originates at point sources is usually what is associated with headline-grabbing stories such as those about Love canal. Figure 9.3: Sources of water pollution Non-point sources of water pollution include oil spilled from cars, trash from streets, fertilizers, animal waste, and insecticides that end up in bays, rivers, and lakes. Point sources include factories and other structures that directly put waste in water.
Nonpoint sources of pollution are diffuse and therefore harder to control. For instance, rain washes oil, grease, and solid pollutants from streets and parking lots into storm drains that carry them into bays and rivers. Likewise, irrigation and rainwater leach fertilizers, herbi- cides, and insecticides from farms and lawns and into streams and lakes.
the direct discharge of wastes from point sources into lakes, rivers, and streams is regulated by a permit program known as the National Pollutant Discharge Elimi- nation System (NPDES). this program, established through the clean Water Act, is administered by the Environmental Protection Agency (EPA) and authorized Nonpoint SourcesPoint Sources Car oil, trash, animal waste, chemicals used on farms and lawns can end upin storm drains and into bodies of water. Factories, sewage treatment plants, large-scale animal feeding operations, and others dispose of waste directly into bodies of water. Consider This What are non-point sources of water pol- lution and why are they more difficult to control than point sources? ben85927_09_c09.indd 379 1/28/14 1:19 PM SEct IoN 9.2 WAtEr Po LLut IoN states. By regulating the wastes discharged, NPDES has helped reduce point-source pollu- tion dramatically. on the other hand, water pollution in the united States is now mainly from nonpoint sources, as reported by the EPA.
In 1991, the u.S. Geological Survey ( uSGS, part of the Department of the Interior) began a systematic, long-term program to monitor watersheds. the National Water-Quality Assess - ment Program (NAWQA), established to help manage surface and groundwater supplies, has involved the collection and analysis of water quality data in over 50 major river basins and aquifer systems [an underground layer of porous rock that holds groundwater] in nearly all 50 states. the program has encompassed three principal categories of investigation: (1) the current conditions of surface water and groundwater; (2) changes in those conditions over time; and (3) major factors—such as climate, geography, and land use—that affect water quality. For each of these categories, the water and sediment have been tested for such pollutants as pes - ticides, plant nutrients, volatile organic compounds, and heavy metals. the NAWQA findings were disturbing.
Water quality is most affected in water - sheds with highest population density and urban development. In agricultural areas, 95 percent of tested streams and 60 percent of shallow wells contained herbicides, insecticides, or both. In urban areas, 99 percent of tested streams and 50 percent of shallow wells had herbi- cides, especially those used on lawns and golf courses. Insecticides were found more frequently in urban streams than in agricultural ones.
the study also found large amounts of plant nutrients in water supplies. For instance, 80 percent of agricultural streams and 70 percent of urban streams were found to contain phosphorus at con- centrations that exceeded EPA guidelines.
Moreover, in agricultural areas, one out of five well-water samples had nitrate con - centrations higher than EPA standards for drinking water. Nitrate contamina- tion can result from nitrogen fertilizers or material from defective septic systems leaching into the groundwater, or it may reflect defects in the wells. Consider This though we might think of rural regions filled with farms as being less polluted than cities, it’s actually the case that agricultural areas have some of the highest rates of air and water pollution in the united States. this is especially true of areas occupied by large-scale factory farms or concentrated animal feeding operations ( cAF os). First review these three sources of information, and then list the major ways in which agri- culture contributes to water pollution and what can be done to reduce this problem:
• http://water.epa.gov/polwaste/nps /agriculture.cfm • http://www.pewenvironment.org /uploadedFiles/PEG/Publications /Fact_Sheet/Animal%20Agriculture %20and%20Water%20Pollution.pdf • http://www.bloomberg.com/news /2012-03-12/water-pollution-from -farming-is-worsening-costing -billions.html ben85927_09_c09.indd 380 1/28/14 1:19 PM SEct IoN 9.2 WAtEr Po LLut IoN Effects of Pollution According to the uN World Water Assessment Programme, about 2.3 billion people suffer from diseases associated with polluted water, and more than 5 million people die from these illnesses each year. Dysentery, typhoid, cholera, and hepatitis A are some of the ailments that result from ingesting water contaminated with harmful microbes. other illnesses—such as malaria, filariasis, yellow fever, and sleeping sickness—are transmitted by vector organisms (such as mosquitoes and tsetse flies) that breed in or live near stagnant, unclean water.
A number of chemical contaminants—including DD t, dioxins, polychlorinated biphenyls (P cBs), and heavy metals—are associated with conditions ranging from skin rashes to vari - ous cancers and birth defects. Excess nitrate in an infant’s drinking water can lead to the “blue baby syndrome” (methemoglobinemia)—a condition in which the child’s digestive system cannot process the nitrate, diminishing the blood’s ability to carry adequate concentrations of oxygen.
Besides affecting human health, water pollution has adverse effects on ecosystems. For instance, while moderate amounts of nutrients in surface water are generally not problematic, large quantities of phosphorus and nitrogen compounds can lead to excessive growth of algae and other nuisance spe - cies. Known as eutrophication, this phenomenon reduces the penetration of sunlight through the water; when the plants die and decompose, the body of water is left with odors, bad taste, and reduced levels of dissolved oxygen.
Low levels of dissolved oxygen can kill fish and shellfish. In addition, aquatic weeds can interfere with recreational activities (such as boating and swimming) and can clog intake by industry and municipal systems.
Some pollutants settle to the bottom of streams, lakes, and harbors, where they may remain for many years. For instance, although DD t and P cBs were banned years ago, they are still found in sedi- ments in many urban and rural streams. they occur at levels harmful to wildlife at more than two-thirds of the urban sites tested. . Heike Kampe/iStock/Thinkstock Use of synthetic nitrogen fertilizers that leach into waterways causes eutrophication pollution, identified in this river by an algal bloom. These algal blooms deplete the water of oxygen, which can be harmful to aquatic creatures. ben85927_09_c09.indd 381 1/28/14 1:19 PM SEct IoN 9.2 WAtEr Po LLut IoN Prevention and Remediation As the old saying goes, an ounce of prevention is worth a pound of cure. this is especially true when it comes to controlling water pollution. Several important steps taken since the passage of the clean Water Act have made surface waters today cleaner in many ways than they were 30 years ago.
For example, industrial wastes are mandated to be neutralized or broken down before being discharged to streams, lakes, and harbors. Moreover, the u.S. government has banned the production and use of certain dangerous pollutants such as DD t and P cBs. In addition, two major changes have been introduced in the handling of sewage. First, smaller, less efficient sewage treatment plants are being replaced with modern, regional plants that include biological treatment, in which microorganisms are used to break down organic mat- ter in the sewage. the newer plants are releasing much cleaner discharges into the receiving bodies of water (rivers, lakes, and ocean).
Second, many jurisdictions throughout the united States are building separate sewer lines for storm water and sanitary wastes. these upgrades are needed because excess water in the older, “combined” sewer systems would simply bypass the treatment process, and untreated sewage would be discharged directly into receiving bodies of water.
to minimize pollutants from nonpoint sources, the EPA is requiring all municipalities to address the problem of runoff from roads and parking lots. At the same time, the use of fer- tilizers and pesticides needs to be reduced. toward this end, county extension agents are educating farmers and homeowners about their proper application and the availability of nutrient testing.
to curtail the use of expensive and potentially harmful pesticides, the approach known as integrated pest management can be implemented. It involves the identification of specific pest problems and the use of nontoxic chemicals and chemical-free alternatives whenever possible. For instance, aphids can be held in check by ladybug beetles and caterpillars can be controlled by applying neem oil to the leaves on which they feed.
Moreover, new urban development projects in many areas are required to implement storm- water management practices. they include such features as: oil and grease traps in storm drains; swales to slow down runoff, allowing it to infiltrate back into groundwater; “wet” detention basins (essentially artificial ponds) that allow solids to settle out of runoff; and artificial wetlands that help break down contaminants in runoff. While such additions may be costly, they significantly improve water quality. they are of course much more expensive to install after those areas have been developed. [. . .] ben85927_09_c09.indd 382 1/28/14 1:19 PM SEct IoN 9.2 WAtEr Po LLut IoN The Future of Clean Water the EPA reports that as a result of the clean Water Act, millions of tons of sewage and indus - trial waste are being treated before they are discharged into u.S. coastal waters. In addition, the majority of lakes and rivers now meet mandated water quality goals.
Yet the future of federal regulation under the clean Water Act is unclear. In 2001, a Supreme court decision (Solid Waste Agency of Northern cook county v. united States Army corps of Engineers, et al.) brought into question the power of federal agencies to regulate activi- ties affecting water quality in smaller, nonnavigable bodies of water. this and related court decisions have set the stage for the EPA and other federal agencies to redefine which bodies of water can be protected from unregulated dumping and discharges under the clean Water Act. As a result, individual states may soon be faced with much greater responsibility for the protection of water resources.
Worldwide, more than one billion people presently lack access to clean water sources, and over two billion live without basic sanitation facilities. A large proportion of those who die from water-related diseases are infants. We would hope that by raising awareness of these issues on an international level, the newly recognized right to clean water will become a real- ity for a much larger percentage of the world’s population.
Adapted from Orlins, J., & Anne W. (2003, May). “The Quest for Clean Water.” the World and I online, 146 . Retrieved from http://www.worldandi.com/newhome/public/2003/may/nspub.asp Used by permission. Apply Your Knowledge Many towns and cities in the united States obtain their drinking water from surface bodies of water, such as lakes, reservoirs, and rivers. In some cases where the water quality is poor, local water authorities have to spend a significant amount of money treating this water before it’s deemed safe enough for public use. these costs are then passed on to customers of that water authority, showing how water pollution and other forms of pollution can have direct economic impacts on the public.
Start by visiting the National Drinking Water Database of the Environmental Working Group (http://www.ewg.org/tap-water/ ). read a little about their research on water pollutants in municipal water systems in the united States and check out their list of cities with the best and worst water quality. Next, enter your zip code in the “What’s in your water?” box near the top of the page to see if your local water authority is in their database. If it is, what is the condi - tion of drinking water in your region? If not, select another city or region near you or where you have family and see how their water quality rates. Do you think drinking water customers should be paying the full price to treat water to safe standards, or should polluters be penal - ized or taxed to pay for cleaning up the water? ben85927_09_c09.indd 383 1/28/14 1:19 PM SEct IoN 9.3 HAzArDou S Su BStAN cES 9.3 Hazardous Substances In the case of air and water pollution, it is usually possible to see the problem, find the source, and try to deal with it. However, as this article by Anne Underwood from Newsweek magazine points out, there is growing concern over the possible health impacts of exposure to a handful of widely used chemicals that are more or less invisible to us. None of these chemicals are toxic, and they have been used for decades with no apparent health impacts. Still, many scientists who study them are now worried that long-term exposure, even at low doses, could have unexpected consequences on our health.
In order to assess the danger for humans exposed to chemicals, toxicologists use the basic rules of the scientific method to design experiments to be conducted on lab animals. These animals are exposed to various doses of a particular chemical, then the results are compared with results from other animals that were given different doses, or to results from animals that were not exposed to the chemical at all. While it is never possible to draw a one-to-one connection between ani - mal tests and possible impacts on humans, problematic results in animal tests are often enough to lead to restrictions on exposure of humans to that chemical. The research described in this article involves both animal tests of these chemicals as well as biomonitoring projects where a group of human subjects is monitored to determine their level of exposure to these chemicals over time .
Health problems that develop in lab animals exposed to a particular chemical that also show up in detectable concentrations in a majority of people tested is cause for concern. Tests with such results often lead to public outcry for tighter regulation of use of those chemicals. However, the chemical industry and companies that make use of those chemicals argue that the chemicals have a proven safety record and that alternatives to these chemicals could prove to be more dangerous. The challenge to scientists is that most of the research conducted on chemicals are known as association studies , which might show an association between the presence of a particular chemical and a health problem but which cannot show cause and effect. In addition, most research that is done on chemical exposure tests just one chemical at a time, which ignores the possibility that a chemical could be benign on its own but could have harmful effects when combined with other chemicals—a situation that more closely resembles what happens in the real world. Indeed, the debate over the regulation of chemicals will continue to be characterized by arguments over the numerous benefits of chemical substances relative to possible impacts on human health and ecosystems.
By Anne Underwood As an Alaskan fisherman, timothy June, 54, used to think that he was safe from industrial pollutants at his home in Haines—a town with a population of 2,400 people and 4,000 eagles, with 20 million acres of protected wilderness nearby. But in early 2007, June agreed to take part in a survey of 35 Americans from seven states. It was a biomonitoring project, in which people’s blood and urine were tested for traces of chemicals—in this case, three potentially hazardous classes of compounds found in common household products like shampoo, tin cans, shower curtains and upholstery. the results—released in November [2007] in a report called “Is It in us?” by a coalition of environmental groups—were not reassuring. Every one of the participants, ranging from an Illinois state legislator to a Massachusetts minister, tested positive for all three classes of contaminants. And while the simple presence of these chem - icals doesn’t necessarily indicate a health risk, the fact that typical Americans carry these chemicals at all shocked June and his fellow participants. As Stephanie Felten, 28, of Aurora, Ill., put it, “Why should chemical companies be allowed to roll the dice on my health?” ben85927_09_c09.indd 384 1/28/14 1:19 PM SEct IoN 9.3 HAzArDou S Su BStAN cES clearly, there are chemicals in our bodies that don’t belong there. the centers for Disease control and Prevention conducts a large, ongoing survey that has found 148 chemicals in Americans of all ages, including lead, mercury, dioxins and P cBs [polychlorinated biphenyls]. other scientists have detected antibacterial agents from liquid soaps in breast milk, infants’ cord blood and the urine of young girls. And in 2005, the Environmental Working Group found an average of 200 chemicals in the cord blood of 10 newborns, including known carcinogens and neurotoxins. “ our babies are being born pre-polluted,” says Sharyle Patton of common - weal, which cosponsored “Is It in us?” “ this is going to be the next big environmental issue after climate change.” the shocking thing to most Americans is that we really don’t know the health effects of many chemicals on the market today. under the toxic Substances control Act of 1976, chemicals already in use were grandfathered in without scrutiny. these include the three classes of com - pounds targeted in “Is It in us?”—a plastic strengthener called bisphenol A (BPA), bromi - nated flame retardants known as PBDEs and plastic softeners called phthalates. the chemical industry says these compounds have been used safely for decades, and certainly they do not have the overtly toxic properties of mercury or lead. But in animal studies and human cell cultures, they mimic hormones, with effects even at minute levels, down to parts per billion.
Scientists say we’re now awash in a chemical brew of hormone-mimicking compounds that didn’t exist 100 years ago. “We’ve changed the nature of nature,” says Devra Lee Davis, direc- tor of the center for Environmental oncology at the university of Pittsburgh. take bisphenol A. It’s a basic constitu- ent of the polycarbonate plastics found in many baby bottles, sippy cups and juice bottles. A highly versatile compound, it is also found in dental sealants, cDs, DVDs and the resin linings of food and beverage containers, including many cans and take- out cartons. But most scientists say small amounts can leach out—and ultimately find their way into our bodies—when the plastics start to break down under high heat or wear and tear. the cDc has found BPA in 92 percent of Americans age 6 and older who were tested. But the chemical industry says it’s safe—and the Food and Drug Administration agrees. “It’s not pos- sible to contact harmful levels of it,” says Steven Hentges of the American chemis - try council, which represents the major chemical companies.
reproductive biologists aren’t so sure.
Patricia Hunt of Washington State univer - sity was alerted to possible dangers of BPA in 1999 when her mouse study on an unrelated topic suddenly went haywire, with dozens of female mice unexpectedly developing chromo- somal abnormalities in the eggs they carried in their ovaries. As it turned out, a lab worker had used the wrong detergent to clean the animals’ cages—one that caused BPA to leach out of the plastic cages and feeding bottles. Hunt tried washing brand-new cages with the same The Canadian Press/Jonathan Hayward Bisphenol A is a key component in polycarbonate plastics commonly used in sport and baby bottles. The plastic can break down under high heat or extended wear, releasing BPA. ben85927_09_c09.indd 385 1/28/14 1:19 PM SEct IoN 9.3 HAzArDou S Su BStAN cES detergent to confirm the source of the problem. She then began studying BPA exposures in unborn rodents, which she followed into adulthood. the results were striking. Almost half the eggs of female mice exposed to low doses of BPA during gestation carried extra copies of chro- mosomes or were missing chromosomes. No one has replicated the findings.
there are other potential effects. Hun - dreds of animal and test-tube studies suggest that low-dose exposures, par- ticularly during gestation, may later lead to breast and prostate cancer, abnormali - ties in the reproductive tract and behav - ioral problems, among other things. But there is disagreement about the implica- tions for human health. two groups con - vened by the National Institutes of Health [NIH] have reached opposite conclusions.
In 2007, advisers to the government’s National toxicology Program found “minimal” cause for concern. Meanwhile, another scientific panel produced a con- sensus statement saying that, based on animal data, common levels of exposure could pose a problem and that further study was needed. “We can’t say there are conclusive data in humans,” says Freder- ick vom Saal of the university of Missouri, who headed the second panel. “But given the fact that we’re seeing irreparable damage in animals, for heaven’s sake, let’s get this out of products our babies are coming in contact with.” No government in the world has seen the need to do that yet. But two weeks ago [January 2008], Michigan rep. John Dingell, chair of the House committee on Energy and commerce, sent letters to seven manufacturers of infant formula asking if their cans were lined with BPA and if they had tested their products for it. In 2006 Whole Foods stopped carrying baby bottles made from polycarbonate plastic, which contains BPA. the chain now sells only BPA- free bottles and sippy cups.
Phthalates have also raised concern. the compounds are used to soften the plastics in prod - ucts ranging from rubber duckies and vinyl shower curtains to certain medical tubing and IV bags. they are also found in hundreds of personal-care products, including many fragrances, body lotions, nail polishes and shampoos. Again, 30 years of data from institutions like the NIH and EPA point to potential problems in animals stemming from prenatal exposure, including abnormalities in the reproductive tract and a decline of sperm quality. Now there is a smattering of human studies, too. In 2006 Danish researchers found that higher levels of a particular phthalate in mothers’ breast milk correlated with lower testosterone in male babies at 1 to 3 months of age. Similarly, Dr. russ Hauser at Harvard studied roughly 500 men at a fertility clinic and found that those with higher levels of certain phthalates in their urine had lower sperm counts and sperm motility. A Swedish study of young military recruits, how - ever, found no such correlation. these are all association studies—which by definition cannot prove cause and effect. Consider This First review the two sources listed below and describe what bisphenol A (BPA) is used for and why it is such a versatile and commercially valuable compound. Next, consider how you might be exposed to bisphenol A and what the major health concerns associated with this exposure are. How do you think we should balance these benefits and potential dangers?
• http://www.health.state.mn.us/divs /eh/risk/chemhazards/bisphenola .html • http://www.niehs.nih.gov/health /topics/agents/sya-bpa/ ben85927_09_c09.indd 386 1/28/14 1:19 PM SEct IoN 9.4 So LID WAStE other scientists are starting to look at what happens when these chemicals are combined. L. Earl Gray Jr., a research biologist at the EPA, has tested mixtures of two or more phthal - ates in animals. He deliberately selected doses of each that were too low to cause effects individually—yet found that as many as 50 percent of male rats who were exposed to the combination in utero developed abnormalities in the reproductive tract. In his latest study, he combined three phthalates with four pesticides and found that at the highest doses, the effects equaled those of a sevenfold dose of a single phthalate. “All the males were malformed,” he says. the toy industry contends that phthalates pose no danger, particularly a widely used one called DINP. this chemical “has been well studied here in the u.S. and in Europe and found to be safe specifically for kids’ products,” says Joan Lawrence, a vice president of the toy Industry Association. She notes that companies cannot easily replace it because none of the potential substitutes “has its lengthy safety record.” Nonetheless, last october, california Gov. Arnold Schwarzenegger signed a ban on the use of six phthalates in children’s products sold in the state—though three of them, including DINP, are prohibited only in items that kids under 3 are likely to put in their mouths. In December, toys “ r” us notified its vendors of its intention to comply with the california ban by Jan. 1, 2009, the date the law takes effect. Mat - tel is already in compliance.
Finally there are the flame retardants, PBDEs . they turn up in fabrics, upholstery, foam mat - tresses, circuit boards and the casings of computers and televisions—and apparently escape into indoor air and dust. Animal studies show they can have negative impacts on learning and memory, sperm counts and thyroid functioning in rats and mice. PBDEs tend to linger a long time in the body, and one mixture in particular seems “quite biologically active, especially dur - ing development, as we’ve seen in studies on rats, mice and fish,” says Linda Birnbaum, direc- tor of experimental toxicology at the EPA. “If I were nursing my baby, I wouldn’t stop because of PBDEs in breast milk, but many of us wish they weren’t there.” According to the EPA, 11 states—including california, Maine, Michigan and New York—have bans on two major types. It could take decades to resolve doubts about the safety of all these chemicals, one way or the other. But timothy June isn’t waiting. He’s stopped buying tomato sauce in tin cans to avoid the BPA, which scientists say tends to leach out of can linings when the contents are particu - larly acidic. He’s ditched his vinyl shower curtain in favor of a cloth one. And he’s considering getting rid of the foam mattress on his fishing boat. “I guess the survey had a bigger impact on me than I realized,” he says. Let’s all hope the chemicals aren’t having an even bigger impact on us.
Adapted from Underwood, A. (2008, January 26). The Chemicals Within. Newsweek. Retrieved from http://www .newsweek.com/2008/01/26/the-chemicals-within.html. Reprinted with permission 9.4 Solid Waste In this Advanced Placement (AP) course review, it is stated that solid waste, waste that is nei - ther liquid nor gaseous, can be broken into two categories—non-municipal solid waste and municipal solid waste . It is also stated that non-municipal solid waste makes up almost 99 per - cent of overall solid waste in the United States, and that municipal solid waste (MSW) accounts for only a little over 1 percent of the total. This would make it seem like MSW is not much of a problem. However, whereas the non-municipal solid waste category refers to byproducts of large-scale industrial, mining, and construction activities, the MSW category refers to the kinds ben85927_09_c09.indd 387 1/28/14 1:19 PM SEct IoN 9.4 So LID WAStE of wastes we all generate on a daily basis. In fact, despite being such a small percentage of the overall total, Americans generate over 200 million tons of MSW annually, roughly two-thirds of a ton per person on average.
Environmental scientists refer to the volume of MSW coming from homes and small businesses as the waste stream, and analysis of the composition of that waste stream reveals some sur- prises. Whereas most Americans would guess that plastic waste would make up the largest por - tion of the waste stream, in actuality it is paper that accounts for the largest share by volume, slightly more than 40 percent. Yard waste, such as grass clippings, makes up the next biggest segment (roughly 13 percent), followed by plastics (12 percent), food waste (12 percent), metals (9 percent), glass (6 percent), and wood (6 percent).
As recently as the 1960s, much of this MSW stream was either disposed of in open dumps, burned in the open, or carried by barge a couple of miles offshore and dumped in the ocean. With the passage of the Solid Waste Disposal Act of 1965, these practices gave way to more careful and costly disposal practices. Today, most MSW is disposed of in sanitary landfills, areas of low ground lined with heavy plastic where solid waste is dumped and then covered with dirt on a daily basis. Another 15 percent of MSW is burned in waste incinerators, often producing electric - ity in the process.
While this article focuses primarily on how municipal solid waste can be disposed of, a more meaningful question would be why we generate so much waste in the first place? Recall the linear versus cyclical discussion in the chapter introduction and the idea that in nature, since waste = food, there really is no waste. The high volume of waste generated by individuals and communities in the United States is thus a symptom of a highly linear system. We’ll see in this and the next section that the three Rs—reduce, reuse, recycle—can help to lower the amount of waste we generate. However, in order to really eliminate the concept of waste, we should also think of a fourth R—redesign. How might we redesign our production and consumption patterns to eliminate waste altogether? Some ideas on this are presented in the Additional resources section at the end of this chapter as well as in the final chapter of the book. By Peter Saundry, Topic Editor In natural systems, there is no such thing as waste. Everything flows in a natural cycle of use and reuse. Living organisms consume materials and eventually return them to the environ - ment, usually in a different form, for reuse. Solid waste (or trash) is a human concept. It refers to a variety of discarded materials, not liquid or gas, that are deemed useless or worthless.
However, what is worthless to one person may be of value to someone else, and solid wastes can be considered to be misplaced resources. Learning effective ways to reduce the amount of wastes produced and to recycle valuable resources contained in the wastes is important if humans wish to maintain a livable and sustainable environment.
Solid waste disposal has been an issue facing humans since they began living together in large, permanent settlements. With the migration of people to urban settings, the volume of solid waste in concentrated areas greatly increased.
Ancient cultures dealt with waste disposal in various ways: they dumped it outside their set- tlements, incorporated some of it into flooring and building materials, and recycled some of ben85927_09_c09.indd 388 1/28/14 1:19 PM SEct IoN 9.4 So LID WAStE it. Dumping and/or burning solid waste has been a standard practice over the centuries. Most communities in the united States dumped or burned their trash until the 1960s, when the Solid Waste Disposal Act of 1965 (part of the clean Air Act) required environmentally sound disposal of waste materials.
Sources and Types of Solid Waste there are two basic sources of solid wastes: non-municipal and municipal. Non-municipal solid waste is the discarded solid material from industry, agriculture, mining, and oil and gas production. It makes up almost 99 percent of all the waste in the united States. Some common items that are classified as non-municipal waste are: construction materials (roofing shingles, electrical fixtures, bricks); waste-water; incinerator resi - dues; ash; scrubber sludge; oil/gas/ mining waste; railroad ties, and pesti - cide containers.
Municipal solid waste is made up of discarded solid materials from resi- dences, businesses, and city build- ings. It makes up a small percentage of waste in the united States, only a little more than one percent of the total. Municipal solid waste consists of materials from plastics to food scraps.
the most common waste product is paper (about 40 percent of the total).
other common components are: yard waste (green waste), plastics, metals, wood, glass and food waste. the composition of the municipal wastes can vary from region to region and from season to season. Food waste, which includes animal and vegetable wastes resulting from the preparation and consumption of food, is commonly known as garbage.
Some solid wastes are detrimental to the health and well-being of humans. these materials are classified as hazardous wastes. Hazardous wastes are defined as materials which are toxic, carcinogenic (cause cancer), mutagenic (cause DNA mutations), teratogenic (cause birth defects), highly flammable, corrosive or explosive. Although hazardous wastes in the united States are supposedly reg - ulated, some obviously hazardous solid wastes are excluded from strict regulation; these include: mining, hazardous household and small business wastes. Consider This What are the major differences among non-municipal, municipal, and hazardous wastes? What are the major components of the municipal solid waste stream? . Huguette Roe/iStock/Thinkstock While municipal solid waste comprises a small portion of solid waste overall, it could be even smaller if more resources were recycled, reused, or composted. ben85927_09_c09.indd 389 1/28/14 1:19 PM SEct IoN 9.4 So LID WAStE Waste Disposal Methods Most solid waste is either sent to landfills (dumped) or to incinerators (burned). ocean dumping has also been a popular way for coastal communities to dispose of their solid wastes.
In this method, large barges carry waste out to sea and dump it into the ocean. that practice is now banned in the united States due to pollution problems it created. Most municipal and non-municipal waste (about 60%) is sent to landfills. Landfills are popular because they are relatively easy to operate and can handle [a] lot of waste material. there are two types of landfills: sanitary landfills and secure landfills.
In a sanitary landfill solid wastes are spread out and compacted in a hole, canyon area or a giant mound. Modern sanitary landfills are lined with layers of clay, sand and plastic. Each day after garbage is dumped in the landfill, it is covered with clay or plastic to prevent redistribu - tion by animals or the wind.
rainwater that percolates through a sanitary landfill is collected in the bottom liner. this liq - uid leachate may contain toxic chemicals such as dioxin, mercury, and pesticides. therefore, it is removed to prevent contamination of local aquifers. the groundwater near the landfill is closely monitored for signs of contamination from the leachate.
As the buried wastes are decomposed by bacteria, gases such as methane and carbon dioxide are produced. Because methane gas is very flammable, it is usually collected with other gases by a system of pipes, separated and then either burned off or used as a source of energy (e.g., home heating and cooking, generating electricity). other gases such as ammonia and hydro - gen sulfide may also be released by the landfill, contributing to air pollution. these gases are also monitored and, if necessary, collected for disposal. Finally, when the landfill reaches its capacity, it is sealed with more layers of clay and sand. Gas and water monitoring activities, though, must continue past the useful life of the landfill.
Secure landfills are designed to handle hazardous wastes. they are basically the same design as sanitary landfills, but they have thicker plastic and clay liners.
Also, wastes are segregated and stored according to type, typically in barrels, which prevents the mixing of incom - patible wastes. Some hazardous waste in the united States is sent to foreign countries for disposal. Developing coun- tries are willing to accept this waste to raise needed monies. recent treaties by the u.N. Environment Programme have addressed the international transport of such hazardous wastes.
Federal regulation mandates that landfills cannot be located near faults, floodplains, wetlands or other bodies of water. In many areas, finding landfill space is not a problem, but in some heavily populated areas it is difficult to find suitable sites. there are, of course, other prob - lems associated with landfills. the liners may eventually leak and contaminate groundwater with toxic leachate. Consider This What is the difference between a sanitary and a secure landfill? What are the major features of each that help to prevent con- tamination of the surrounding environ- ment? Are these features 100 percent effective at preventing contamination or the spread of pollution to surrounding areas? ben85927_09_c09.indd 390 1/28/14 1:19 PM SEct IoN 9.4 So LID WAStE Apply Your Knowledge Even as efforts are made to increase rates of reuse and recycling, Americans will continue to generate significant volumes of solid waste that will need to be safely disposed of. In order to be in compliance with federal law, waste handling companies need to be very particular about where they locate sanitary landfill facilities and how they design, build, and operate these facilities. Start by reviewing this concise guide to landfill design and operation (http://www .govengr.com/ArticlesMay06/landfilldesign.pdf ). Next, imagine that you’ve been hired as the chief scientist to determine whether a new sanitary landfill can be safely developed in a par- ticular location. What kinds of information will you need to acquire to answer this question?
How would you communicate your findings to the public? Landfills also produce polluting gases, and landfill vehicle traffic can be a source of noise and particulate pollutants for any nearby community.
About 15 percent of the municipal solid waste in the united States is incinerated. Incineration is the burning of solid wastes at high temperatures ( .1000 8 c). though par - ticulate matter, such as ash, remains after the incineration, the sheer volume of the waste is reduced by about 85 percent. Ash is much more compact than unburned solid waste. In addition to the volume reduction of the waste, the heat from the trash that is incinerated in large-scale facilities can be used to produce electric power. this process is called waste- to-energy. there are two kinds of waste-to-energy systems: mass burn incinerators and refuse-derived incinerators.
As with any combustion process, the main environmental concern is air quality. Incineration releases various air pollutants (particulates, sulfur dioxide, nitrogen oxides, and methane) into the atmosphere. Heavy metals (e.g., lead, mercury) and other chemical toxins (e.g., diox - ins) can also be released. Many communities do not want incinerators within their city limits.
Incinerators are also costly to build and to maintain when compared to landfills.
Waste Management one of the best ways to handle solid waste is to reuse as much of it as possible. In the united States, about 22 percent of the solid waste generated by municipalities is recycled. recycling is the process by which the materials in consumer goods are returned to the production facil - ity and remade into new products. there are two basic types of recycling: post-consumer and pre-consumer.
Post-consumer recycling involves products that consumers, rather than industry or pro- ducers, have recycled. Aluminum cans, plastic bottles and newspapers are typical materials involved in post-consumer recycling. Pre-consumer recycling involves recycling the mate- rials at the production facility. For example, a plant that makes plastic bottles may recycle any rejected bottles which do not fit certain specifications. It is material that a consumer has never purchased. Pre-consumer recycling is much more common and makes up a larger per- centage of the total. ben85927_09_c09.indd 391 1/28/14 1:19 PM SEct IoN 9.4 So LID WAStE composting is the biological decomposition of organic material under aerobic conditions.
this process is used to recycle organic yard wastes and household food wastes. During the composting process, bacteria and other microorganisms convert the organic matter into humus, an important component of fertile soil.
the composting process takes about a year. Some communities ban the disposal of yard waste with regular trash and instead require the use of green bins . the green bins, filled with leaves, grass clippings and tree trimmings, are sent to a municipal compost facility. residents close to such a facility often complain, though, of the odor from the compost. composting is one way to ensure that the nutrients from waste materials are returned to the soil to be used by other organisms, just like they would be in natural systems.
Environmental scientists have set out a waste management protocol that defines the disposal methods that benefit the environment the most. their protocol declares the following: reduce, reuse, recycle, compost, bury, and burn. the most effective way to decrease the amount of trash is to reduce the amount produced in the first place. the second most effective way is to reuse materials. these actions would lengthen the useable lives of landfills and lessen the load on incinerators.
Some ways to reduce consumption include: reducing the amount of packag- ing; reducing the number of individual packages; using less material to make a product and buying only what you can consume. can producers have reduced the amount of aluminum in soda cans by 40 percent since 1970. concentrated juices and laundry detergents require fewer packaging materials.
reusing materials multiple times or for another purpose can also save on solid wastes. Some examples of this include:
reusing newsprint as a paper towel to clean items and soak up liquids; refill- ing a water bottle rather than buying a new one; using reuseable cloth napkins instead of paper napkins; reusable cups instead of paper cups; reusing the backside of printed paper as scratch paper; and reusing grocery bags for garbage collection. Adapted from UCCP (Content Source); Peter Saundry (Topic Editor) “AP Environmental Science Chapter 17— Solid Waste.” In: Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment). First published in the Encyclopedia of Earth Novem- ber 25, 2008; last revised date November 25, 2008; retrieved April 17, 2011, http://www.eoearth.org/article /AP_Environmental_Science_ chapter_17-_Solid_Waste . . Sonia Caron/iStock/Thinkstock More communities are providing citizens with access to recycling and green waste programs.
These programs help meet the waste management protocol outlined by environmental scientists:
reduce, reuse, recycle, compost, bury, and burn. ben85927_09_c09.indd 392 1/28/14 1:19 PM SEct IoN 9.5 Case History— reCyCling 9.5 Case History—Recycling One way to reduce the volume of municipal solid waste headed to landfills is to recycle it. Advo- cates for recycling often make the argument that this approach helps to conserve scarce landfill space. However, in this Popular Mechanics article by Alex Hutchinson, we learn that, for the most part, the scarcity of landfill space is probably the least important argument in favor of recycling. Instead, it is the energy saved by recycling aluminum, plastic, paper, and glass that is the most important reasons for this waste management approach.
On the face of it, driving heavy trucks around to pick up empty aluminum cans and plastic bot - tles may not seem like a very energy-efficient thing to do. But by using an approach known as life-cycle analysis (LCA), scientists have determined that in most cases it takes far less energy to produce a can or bottle from recycled materials than it does to produce one from scratch.
An LCA examines all of the environmental and energy impacts of a product over its entire life cycle, from raw material extraction to processing, use, and disposal. Even after accounting for all of the energy used to collect, sort, clean, process, and re-use recyclable material, it is still far more energy intensive and environmentally destructive to mine raw material (such as bauxite ore for aluminum cans) to create a new, finished product. When we factor in all of the other environmental costs of raw material extraction, refining, and manufacture (e.g., air and water pollution), recycling’s advantages become even more apparent.
Despite this advantage, markets for recyclable materials are not yet well developed in many regions. As a result, it frequently costs local governments more money to collect recyclable mate- rials than they are able to recoup from selling them. This situation has begun to change due to growing demand for recycled material in China. Although the article below highlights the posi - tive side of sending used newsprint to China for recycling, skeptics point out the more problem - atic issue of shipping electronic waste to that country.
By Alex Hutchinson The Environmental Debate According to one calculation, all the garbage produced in the u.S. for the next 1000 years could fit into a landfill 100 yards deep and 35 miles across on each side—not that big (unless you happen to live in the neighborhood). or put another way, it would take another 20 years to run through the landfills that the u.S. has already built. So the notion that we’re running out of landfill space—the original impetus for the recycling boom—turns out to have been a red herring. recycling critics also question the wisdom of deploying fleets of large, fuel-hungry trucks that duplicate the routes already driven by garbage trucks to take recyclables to repro - cessing facilities that burn energy and emit pollution. And the resources saved aren’t always that rare: the virgin material conserved by recycling glass is mainly sand, and we’re a long, long way from a “peak sand” crisis.
to resolve the environmental debate once and for all, experts have begun to conduct detailed life-cycle analyses on recycled goods, calculating the energy consumed from the moment they’re picked up by recycling trucks until they are processed into brand-new products.
When compared with the amount of energy required to send the same goods to landfills or incinerators and make new products from scratch, the results vary dramatically, depending on the material. ben85927_09_c09.indd 393 1/28/14 1:19 PM SEct IoN 9.5 Case History— reCyCling Aluminum, for example, requires 96 percent less energy to make from recycled cans than it does to process from bauxite. At the other end of the spectrum, recycled glass uses only about 21 percent less energy—but it still comes out ahead, according to a study by Washington- based environmental consultant Jeffrey Morris. recycled plastic bottles use 76 percent less energy and newsprint about 45 percent less, he found. Across the board, the key factor is the energy intensity of extracting virgin materials, which is an order of magnitude higher than that of recovering the same material through recycling. “Even if you doubled the emissions from collecting recyclables, it wouldn’t come close,” Morris says. overall, he found, it takes 10.4 million Btu to manufacture products from a ton of recyclables, compared to 23.3 million Btu for virgin materials. And all of the collecting, hauling and processing of those recyclables adds just 0.9 million Btu. that doesn’t mean the system is always efficient. the best recycling is closed- loop: Steel cans and glass bottles are recy- cled into more cans and bottles, which are in turn recyclable. But some materi - als are currently “downcycled” into less desirable products that can be recycled no further. Soft-drink bottles made from PE t (polyethylene terephthalate), for example, often end up as polyester fibers in clothing or carpets. It is possible to make new PE t bottles from recycled stock, but the process is currently more expensive than making them from petroleum. Supply and demand also come into play: Brit - ain imports so much wine that recycled green glass is simply used as construction aggregate; recycling it consumes more energy than just sending the bottles to a landfill. The Economic Debate thanks to life-cycle assessments, there’s no longer any serious debate among policymakers about whether recycling makes sense environmentally. the economic debate, however, still rages. It’s surprisingly difficult to get a clear picture of how much municipal recycling pro - grams cost compared to landfilling or incineration, because of hidden subsidies and long- term price guarantees given to all types of waste disposal. But it’s fair to say that, at this point, it generally costs a little more to recycle waste than it does to dump it.
recycling economics are fundamentally local, since hauling and tipping fees—paid to truck - ing operations and processing facilities that handle waste—vary from about $24 per ton in the south central and west central regions of the u.S., to more than $70 in the Northeast, according to the most recent figures from the National Solid Wastes Management Associa - tion (NSWMA). other local costs also differ dramatically. taking some very rough estimates for illustration, it might cost $150 a ton to collect and process mixed recyclables. the price those recyclables fetch reached about $100 a ton earlier this year—so if the cost of taking that material to a landfill is more than $50 a ton, the recycling program will be a money saver. With a national average tipping fee of $34.29, most curbside programs still cost money. Consider This After factoring in all of the energy it takes to collect aluminum cans, plastic and glass bottles, and paper and then put this mate- rial through a recycling process, are there environmental benefits? Why? What is the main reason that recycling reduces envi- ronmental impacts? ben85927_09_c09.indd 394 1/28/14 1:19 PM SEct IoN 9.5 Case History— reCyCling those numbers are changing rapidly, though. this past summer [2008], the price for virtually all recyclables hit record highs, boosted by larger market forces. Plastics are made from oil, which has caused the price for recyclable plastic to double in the past two years. Glass is made of cheap sand, but it also contains energy-intensive soda ash, so the price of recycled glass has risen in lock step with energy prices. But the biggest factor, says industry veteran Jerry Pow- ell, the editor of resource recycling Magazine, is “the recycling market’s most famous five- letter word, c-H-I-N-A.” With its ravenous demand for raw materials, china benefits from ultracheap shipping in container ships that would otherwise sail back to Asia empty. “ china is a tree-poor country,” says chaz Miller of the NSWMA, “so our recycled paper has become their forest, in a way.” Just as crucially, while the current record-high prices may not endure, few fear the precipitous plunge that rocked the recycling market in 1995. Buyers are seeking long-term contracts with a guaranteed steady supply, which helps smooth the market fluctuations.
If recycling is truly becoming prof- itable, then that should end the debate—we can simply let the market decide what to recycle. the problem, according to university of Michigan professor richard Porter, author of The Economics of Waste, is that recy- cling markets don’t function smoothly.
If you drink a bottle of water, the apparent cost to you of throwing out the empty or recycling it are identical:
zero. one way to create incentives for recycling is a “pay as you throw” pol - icy, where homeowners pay for gar - bage collection based on the size of their garbage cans. More than 7000 communities, serv - ing about a quarter of the u.S. population, have introduced this policy with success—their recycling rates are about 30 percent higher as a result.
New Technology From a consumer’s point of view, one of the biggest knocks against recycling is the mind- numbingly complex rules about which plastics can be recycled when and in what forms. So those of us who don’t live in San Francisco can only envy that city’s residents, who since April [2008] have been instructed to toss any and all rigid plastic (and any other recyclables) into the same bin. From there, it goes to the city’s state-of-the-art recycle central facility, where each day 700 tons of flowerpots, Mr. Potato Head toys and other items are swiftly sorted into the appropriate piles by an array of technological wizardry—magnets for steel, eddy currents that repel aluminum, spinning disks and vacuum tubes that suspend gravity for plastics— along with a phalanx of eagle-eyed humans wearing thick gloves. Digital Vision/Photodisc/Thinkstock Paper recycling facilities provide recycled paper manufacturers with the materials they need to produce “tree-free” paper. Countries who lack the resources to make new paper, such as China, have created a market for recycled paper. ben85927_09_c09.indd 395 1/28/14 1:19 PM SEct IoN 9.5 Case History— reCyCling this single-stream sorting technology isn’t perfect. At some facilities, plastic bags snarl the conveyer belts, and broken glass contaminates other materials. But it represents the most important trend in recycling technology—and it’s improving. Even though a typical single- stream facility costs $8 million to $10 million, more than double the price of a dual-stream facility (where paper is collected separately), they have increased in number from 70 in 2001 to 160 in 2007.
one major advantage of single-stream is convenience: When Madison, Wis., changed from dual-stream to single-stream in 2005, the recycling rate leaped by 25 percent in the first year, while the projected annual cost increased by less than $3 per household. It’s a pattern that is being repeated elsewhere: About 700 of the country’s 10,000 curbside programs have made the switch.
Another benefit is efficiency, since collection costs typically eat up 50 to 60 percent of the budget. “ that means efficiencies at the curb are crucial,” says Lori Scozzafava of the Solid Waste Association of North America. Houston, which boasts the nation’s worst recycling rate (2.6 percent), has a voluntary recycling program that forces its trucks to drive long distances between pickups. Single-stream collection, on the other hand, speeds up the process dra- matically, especially with new trucks that empty bins automatically. Besides saving money in the long run, this increased efficiency, along with the greater volumes that people recycle, is allowing more types of plastics to be recovered.
The Verdict Even after the environmental and economic questions have been answered, the decision about how much to recycle depends on how you reconcile those two factors. “High recycling rates are usually a function of, first, a political decision, and second, the strength of local markets,” Miller says. San Francisco’s 70 percent recycling rate isn’t enough for Mayor Gavin Newsom, who wants to ramp it up to 75 percent—even if that means making recycling compulsory.
Houston’s willingness to squander resources with its paltry recycling rate is also as much a political decision as it is an economic one.
Most cities lie somewhere between those two extremes. For them, recycling is generally desirable, but it’s not automatically good and efficient and cheap. It takes significant up-front capital investment to implement a state-of-the-art single-stream recycling program. For that reason, the newfound stability of the recycling market is just as important as the high prices, because it allows cities to plan investments around future revenue streams. “ chicago used to pay haulers to take its recycled materials,” says Ed Skernolis of the National recycling coali - tion. Now, it has invested $24 million to buy recycling carts for 600,000 homes and will deliver the recyclables to a single-stream processing facility—which will now pay the city instead of being paid. ultimately, every community will develop its own unique program. “ the bigger the city,” Por - ter says, “the more you can recycle.” the dividing line between environmental and economic factors will also begin to blur. on the chicago climate Exchange, the world’s first greenhouse- gas trading market, the price for a ton of avoided carbon-dioxide emissions peaked at over $7 this summer. Morris has created a model for municipal waste decision-makers that assigns values to environmental impacts ranging from toxins to acid rain and greenhouse gases. Most ben85927_09_c09.indd 396 1/28/14 1:19 PM Su MMA rY & rES ourc ES telling, though, is a recent study that found that about 90 percent of the material going to landfills has a market value. Given today’s economy, we won’t keep burying that value for long.
Adapted from Hutchinson, A. (2008, December). Is Recycling Worth It? Popular Mechanics. Copyright © 2008, Alex Hutchinson. Retrieved from http://www.popularmechanics.com/science/environment/recycling/4291566 .
Reprinted by permission of the author.
Summary & Resources chapter Summary Virtually all human activities—from driving to work to growing food—generate byproducts known as pollution and waste. In contrast, natural systems such as forests or grasslands gen - erate essentially no pollution or waste since most byproducts (such as leaves dropping from a tree or excrement from animals) prove to be a useful resource for other organisms. In small quantities human-generated pollution and waste can also be assimilated and broken down by natural processes. However, as human populations have grown and our rates of consumption and use of technology have increased, pollution and waste production have exceeded nature’s “assimilative capacity” and have begun to affect human and ecosystem health.
In the case of air and water pollution, environmental scientists typically approach their man - agement by breaking down the sources of pollution into categories. Examples of subcatego - ries include point source or non-point source and stationary or mobile. A coal-fired power plant would be an example of a stationary source of air pollution and might also be a point source for water pollution. Point source and stationary sources of pollution thus typically refer to large-scale, easily identifiable sources of pollution. In contrast, an individual car that leaks oil onto a parking lot that is then carried by a rainstorm into a nearby stream represents a non-point source of water pollution. the car is also a mobile source of air pollution. Non- point sources and mobile sources of air and water pollution are generally more difficult to regulate and control than stationary, point sources of pollution.
regulations such as the clean Air Act and clean Water Act have had a significant and positive impact on our environment in recent decades. In particular these regulations have addressed the highly visible forms of pollution generated by stationary, point sources of pollution. As a result, news stories of rivers catching on fire, whole towns falling ill due to air pollution, and lakes being too dangerous to swim or fish in are now rare. However, regulations have proven less effective and more difficult to design for less visible and obvious forms of pollution. In particular, most serious air pollution events today are the result of dispersed, non-point, and mobile sources. Likewise, non-point runoff from lawns, parking lots, and farms represents the most significant threat to water quality.
Scientists studying the links between exposure to pollution or hazardous substances and human and ecosystem health face a number of challenges. the first is designing an experi - ment where a researcher can maintain some control over conditions. Since the production and movement of pollution through the environment is difficult to predict, and since people are exposed to so many possible pollutants in different ways throughout the day, determin - ing a one-to-one relationship between pollution and health is often impossible. In addition, many pollutants and hazardous substances may not cause immediate or acute reactions.
Instead, prolonged exposure over a long period of time worries many experts. As a result, sci - entists use a combination of research approaches, often based on the scientific method, which ben85927_09_c09.indd 397 1/28/14 1:19 PM Su MMA rY & rES ourc ES include experimenting on lab animals and long-term monitoring projects of people to try to understand how exposure to pollution and hazardous substances might affect us over time.
In the final chapter we turn our attention to some of the political, economic, and ethical issues surrounding the environment. Given that air and water pollution, along with solid and hazard- ous wastes, probably cannot be eliminated entirely from our modern society, there is much room for debate over the appropriate level of these pollutants and how to manage them in a way that balances concerns over the environment with economic and political realities. Working Toward Solutions Most developed, industrialized countries like the united States have domestic air pollution laws that have improved air quality in recent decades. In the united States, the clean Air Act (cAA) was first passed in 1970 and was further strengthened in 1990. the cAA sets goals and standards for specific air pollutants and uses a combination of penalties and market-based incentives to achieve compliance. Because air pollution can be released in one location and easily blown across national boundaries to another location, major countries of the world have ratified the convention on Long- range transboundary Air Pollution. the convention focuses on scientific cooperation and dialog between countries to help reduce the problem of transboundary or cross-border air pollution. currently, china has some of the worst air pol - lution conditions in the world, with one study concluding that 7 of the 10 most air-polluted cities globally are in that country. other research now estimates that air pollution contributes to 1.2 million premature deaths annually in china ( http://www.nytimes.com/2013/04/02 /world/asia/air-pollution-linked-to-1-2-million-deaths-in-china.html ).
Like air pollution, water pollution is also monitored and regulated in most developed coun - tries. In the united States, the clean Water Act ( cWA) was first enacted in 1972 and strength - ened in 1987. the cWA sets standards for water quality and water purity and, in combination with the Safe Drinking Water Act (1974), helps to ensure the safety of municipal drinking water supplies. An interesting example of how air and water pollution are linked can be found with the case of mercury. Mercury is emitted from industrial facilities such as coal-fired power plants and waste incinerators, and it eventually settles in lakes, rivers, and open ocean where it can be ingested by fish (a good diagram of this can be found in this article: http:// grist.org/food/mercury-in-seafood-where-does-it-come-from/ ). Eating fish high in mercury, such as tuna and swordfish, can lead to elevated levels of mercury in our bloodstream caus - ing neurological damage, kidney damage, and other serious health impacts. In January 2013, 140 countries, including the united States, finalized an international agreement to reduce and eventually eliminate the use of mercury in many products. the agreement will also help limit the emissions of mercury from coal-fired power plants and waste incinerators. However, in the united States, proposals to limit mercury emissions from power plants and industrial facilities have been strongly opposed by affected industries.
one of the most well-known urban water quality programs is in New York city. the city draws most of its drinking water from reservoirs located over 100 miles to the north in the catskill region of New York State. Historically, low population levels and large areas of forests and wetlands in the catskill region helped keep water quality high. However, as population and development increased in that area, New York city began to see a decline in their water quality. Faced with the prospect of having to build additional water treatment plants at an expense of (continued) ben85927_09_c09.indd 398 1/28/14 1:19 PM Su MMA rY & rES ourc ES Working Toward Solutions (continued) billions of dollars, New York city took a different approach. they worked with communities, landowners, and farmers in the catskill region to help them reduce or eliminate activities that were polluting the drinking water reservoirs. this approach, known as source protection, focuses on preventing a pollution problem in the first place rather than trying to clean up a problem after it occurs.
there are federal laws in the united States that regulate the release and clean-up of acutely toxic substances, but there is less regulation of the common chemical compounds discussed in section 9.3. the comprehensive Environmental response, compensation and Liability Act (cErc LA) was passed in 1980 and strengthened in 1996. cErc LA requires the clean-up of sites contaminated with toxic waste and is sometimes referred to as “Superfund.” the Emer - gency Planning and community right-to-Know Act (1986) requires large industrial facili - ties to provide information to the EPA and the public about chemicals they release into the air or water. the EPA uses this information, and other data, in its toxic release Inventory or tr I Program. tr I allows you to see what kinds of toxic chemicals might be being released by industrial and other facilities near where you live ( http://www.epa.gov/tri/ ). the idea here is that citizens deserve to know if they are being exposed to chemical emissions that might be damaging their health.
In just the past few years, there has been a flurry of state and local bans on the three chemical compounds described in section 9.3—bisphenol A, phthalates, and polybrominated diphenyl ethers (PBDEs). Bisphenol A bans have focused mainly on the use of this chemical in baby and infant feeding bottles (http://news.consumerreports.org/safety/2011/10/california -bpa-ban.html and http://www.saferstates.com/toxics_in_our_lives/chemicals_of_concern /BPA.html ). Phthalate bans are focused primarily on plastic toys ( http://www.pbs.org/now /shows/412/ban-phthalates.html and http://www.saferstates.com/2009/01/californias -pht.html#. uX3 cE6JJN4s ). PBDE bans are focused on a wider variety of consumer products ( http://www.saferstates.com/toxics_in_our_lives/chemicals_of_concern/PBDE\ s.html and http://watoxics.org/news/pressroom/press-releases/pbde-victory ). Solid waste management is now highly regulated in countries such as the united States. No longer is garbage legally dumped in open piles, burned in the open, or dumped out at sea.
Sanitary landfills are closely monitored and managed. However, much more can be done to minimize the amount of waste sent to landfills in the first place. At present ten states in the united States have what are known as “bottle bills” where consumers pay a 5- or 10-cent deposit on bottles and cans that is refundable if the containers are returned for recycling.
recycling rates in states with a bottle bill are over twice as high as those in states without such legislation (http://www.bottlebill.org/about/whatis.htm and http://www.bottlebill .org/legislation/usa.htm ). clearer recycling labels is the goal of the How2 recycle campaign (http://www.how2recycle.info/ ), an effort to help consumers recycle more of their household waste. In contrast, the cradle-to-cradle ( c2c) concept is an approach that encourages manu - facturers to create products that are easily broken down and reused. the c2c approach seeks to mimic natural systems where all waste = food ( http://www.c2ccertified.org/ and http:// youtu.be/Io rjz8i tVoo ). ben85927_09_c09.indd 399 1/28/14 1:19 PM Su MMA rY & rES ourc ES Post- test 1. Factors such as temperature, humidity, and air movement make it easier to analyze and measure air pollution. a. t rue b. False 2. Low levels of dissolved oxygen can revitalize fish and shellfish. a. t rue b. False 3. Bisphenol A (BPA) is an example of a hormone-mimicking compound. a. t rue b. False 4. the most common form of waste in the municipal solid waste stream in the united States is a. plastic. b. disposable diapers. c. food waste. d. paper. 5. It takes 96 percent less energy to make an aluminum can from recycled materials than it does to process it from new materials. a. t rue b. False 6. Which of the following is N ot involved in the study of source-receptor relationships? a. How air pollutants travel b. t he effects air pollutants have on humans c. t he effects air pollutants have on plants d. t he implementation of anti-pollution laws 7. A facility with three underground storage tanks that leak chemicals would be an example of a. point source pollution. b. non-point source pollution. c. thermal pollution. d. watershed pollution. 8. Association studies on the health impacts of exposures to chemical compounds can definitely prove a cause and effect. a. t rue b. False 9. Wrapping a package to be mailed in a used brown paper grocery bag is an example of a. reducing. b. recycling. c. reusing. d. composting. ben85927_09_c09.indd 400 1/28/14 1:19 PM Su MMA rY & rES ourc ES 10. the single most important reason to promote recycling is because we are running out of landfill space a. t rue b. False Answers 1. b. False. the answer can be found in section 9.1. 2. b. False. the answer can be found in section 9.2. 3. a. true. the answer can be found in section 9.3. 4. d. paper. the answer can be found in section 9.4. 5. a. true. the answer can be found in section 9.5. 6. d. the implementation of anti-pollution laws. the answer can be found in section 9.1. 7. a. point source pollution. the answer can be found in section 9.2. 8. b. False. the answer can be found in section 9.3. 9. c. reusing. the answer can be found in section 9.4. 10. b. False. the answer can be found in section 9.5. Key Ideas • the Environmental Protection Agency (EPA) regulates six criteria air pollutants:
carbon monoxide ( co ), lead (Pb), nitrogen dioxide (N o2), ozone ( o3), particulate matter (PM), and sulfur dioxide (S o2). Primary air pollutants are emitted directly into the air, whereas secondary air pollutants are formed through chemical reactions in the atmosphere. Scientists studying the health and environmental impacts of air pollution use the concept of source-receptor relationship to understand how pollu - tion impacts humans and other organisms. the clean Air Act empowers the EPA to regulate and control air pollution emissions to an acceptable level. • Water pollution can take many forms, including chemical wastes, harmful bacte- ria, excess fertilizers, sediment erosion, and trash dumped into lakes, rivers, or the ocean. Scientists typically classify water pollution into two broad categories, point source and non-point source. Point sources are discrete, identifiable locations, such as a leaking underwater storage tank. Non-point sources are diffuse and spread out, such as pollution runoff from streets, parking lots, or farm fields. the clean Water Act is the primary regulatory tool used by the EPA to monitor and control discharges of pollutants into the nation’s waterways. • Besides acutely toxic chemicals, scientists are also growing concerned over pro- longed human exposure to chemical compounds used in many everyday products that we come in contact with. In particular, there is growing evidence that chemicals such as bisphenol A, phthalates, and polybrominated diphenyl ethers—which are used in plastic bottles, cans, toys, electronics, and many other consumer products— can cause unexpected health impacts over time. these chemicals accumulate in our bodies and can mimic or behave like hormones with possible impacts on the repro- ductive system. the chemical industry argues that these compounds have been in use for decades and that any health concerns are outweighed by their benefits. • Natural systems, such as forests or grasslands, produce no waste, since any waste from one organism is broken down and re-used by other organisms. In human systems, however, waste products can be categorized as non-municipal—waste products from industry, agriculture, and mining—and municipal solid waste (MSW)—discarded material from homes and businesses. Most MSW in the united States is disposed of in sanitary landfills, although roughly 15 percent is incinerated or burned. recycling, composting, reducing, and reusing are all ways to decrease the volume of MSW we generate and lower our overall environmental impact. ben85927_09_c09.indd 401 1/28/14 1:19 PM Su MMA rY & rES ourc ES • It is often assumed that saving landfill space is the main environmental argument for recycling. However, life-cycle analysis, an evaluation of the overall environmen- tal impact of a product or process, shows that the key benefit of recycling is that it dramatically reduces the energy and resources needed to make new products.
Aluminum recycling is especially effective at reducing energy and resource use. It takes 96 percent less energy to make a recycled aluminum can than it does to make a new one from raw material. Despite the environmental benefits, recycling rates vary dramatically across the country in large part due to economic factors. New technolo- gies and more stable markets for recycled material are helping to increase recycling rates in the united States. critical thinking and Discussion Questions 1. Based on what you know about the scientific method, how might you design an experiment to help the EPA determine what levels of air pollution qualify as an “acceptable risk” to human health and welfare? If you were in charge of this research, would you advise the EPA to set pollution standards precisely at this level, or would you recommend that they err on the side of caution and set the standards even lower? Why? 2. By definition, non-point sources of water pollution are harder to identify and regu- late than point sources. If you were put in charge of a regional water authority and given responsibility to reduce non-point source pollution into local drinking water reservoirs, what are some of the first steps you would take? How would you gather information on this problem, and what approaches might you use to regulate it? 3. When faced with an environmental public health issue, such as whether or not to more tightly regulate chemical compounds such as bisphenol A and phthalates, politicians usually hear testimony and seek input from scientists as well as repre- sentatives of the chemical industry. In section 9.3 we saw how many scientists were growing increasingly concerned about the possible health dangers of such chemicals while representatives of the chemical industry argued that they were safe. Is there any reason why politicians should weigh the testimony of scientists any more or less than that of representatives of the chemical industry? Should the financial stake that industry representatives have in the outcome of any policy debate disqualify them from being part of this process? 4. What does it mean to say that in natural systems “there is no such thing as waste?” In different terms, it is sometimes stated that in nature, “waste = food.” What does this mean? Why don’t natural systems produce “waste,” and what is it about human systems that cause us to generate so much of it? 5. Section 9.5 makes clear that despite some skepticism, recycling aluminum, glass, plastic, and paper really does deliver environmental benefits. However it also makes clear that nationally we only recycle about 20 percent of what we could be recycling, while cities such as Houston have recycling rates of only 2 percent. What more could we do to bring recycling rates up to 50 percent or higher? What combination of mandates or voluntary incentives would you favor to increase our rate of recycling as a nation? ben85927_09_c09.indd 402 1/28/14 1:19 PM Su MMA rY & rES ourc ES Air Pollution Control Act Enacted in 1955, the first Clean air act in the United states to address the national environmental problem of air pollution.
association studies a scientific experi - ment that seeks to determine if there is an association between exposure to a particular chemical compound and a specific health problem. biomonitoring a scientific technique for assessing human exposures to natural and synthetic chemicals, based on sampling and analysis of an individual’s tissues and fluids.
bisphenol A A chemical compound that is a component of several commercially useful types of plastic. carcinogenic Having the potential to cause cancer. Clean Air Act A law that was passed in 1963, and then amended in 1970 and 1990, that details the EPA’s role in protecting and improving air quality and the stratospheric ozone layer. Clean Water Act the primary federal law in the united States governing water pollution, whose purpose is to “restore and maintain the chemical, physical, and biological integ- rity of the nation’s waters.” criteria air pollutants the six most com - mon air pollutants, which includes carbon monoxide, lead, nitrogen dioxide, ozone, particulate matter, and sulfur dioxide. emissions release of pollutants into the atmosphere from stationary sources (such as factories) and vehicles. eutrophication the changes that take place when excess nutrients, such as nitro- gen or phosphorous, are added to lakes, rivers, or other aquatic systems resulting in overgrowth of algae and aquatic plant life.
green bins containers that some communi - ties use to collect yard waste such as leaves, grass clippings, and tree trimmings so that the waste can be sent to a municipal com - post facility. hydroelectric the generation of electricity through the conversion of the energy of run- ning water.
incineration the burning of solids wastes at high temperature until reduced to ash.
incinerator A furnace or container for burning waste material at high temperatures until it is reduced to ash.
landfills Waste disposal site where solid waste is buried between layers of dirt. life-cycle analysis Evaluation of the total environmental impact of a product or service at every stage of its existence includ- ing production, transportation, use, and disposal. municipal solid waste Waste generated in households, commercial business establish - ments, and city buildings. mutagenic An agent, such as a chemical, ultraviolet light, or a radioactive element, that can induce or increase the frequency of mutation in an organism. non-municipal solid waste Waste from industry, agriculture, mining, and oil and gas production. Key terms ben85927_09_c09.indd 403 1/28/14 1:19 PM Su MMA rY & rES ourc ES non-point source Large or dispersed land areas, such as crop fields and parking lots, that discharge pollutants into the environ- ment over a large area. oxidation the chemical combination of a substance with oxygen.
PBDEs Polybrominated diphenyl ethers; organobromine compounds that are used as flame retardants. phthalates Any of various salts or organic compounds of phthalic acid frequently used as plasticizers and in solvents. point source single identifiable source, such as a smokestack or drainpipe, that dis - charges pollutants into the environment.
post-consumer recycling the use of mate - rials generated from residential and con- sumer waste for new or similar purposes. pre-consumer recycling the recycling of materials directly from a production facility; materials that have never been purchased by a consumer.
primary air pollutants Pollutants that are emitted directly into the atmosphere. remediation the act or process of correct - ing a fault or deficiency. sanitary landfill Waste disposal site in which waste is spread in thin layers, com - pacted, and covered with layers of clay, sand, and plastic in order to minimize water pollu - tion from runoff and leaching. secondary air pollutants Pollutants that are formed through chemical reactions in the atmosphere. secure landfills Waste disposal site designed specifically to handle hazardous waste in which waste is spread in thin layers, compacted, and covered with thicker layers of clay and plastic, and where wastes are segregated and stored according to type to prevent the mixing of incompatible wastes. solid waste Any unwanted or discarded material that is not a liquid or a gas. source-receptor relationship the science of understanding how air pollutants move from the emission source to where they end up or deposit and the effects that they have on people or other organisms once they end up there.
teratogenic Substances or agents that can interfere with embryo development. thermal pollution the discharge of heated water into a river, lake, or other body of water, causing a rise in temperature that endangers aquatic life.
waste stream term environmental scien - tists use to refer to the volume of municipal solid waste that comes from homes and small businesses. Additional resources chapter 11 of The Habitable Planet online environmental science textbook provides a good overview of air and atmospheric pollution ( http://www.learner.org/courses/envsci/unit /text.php?unit=11&secNum=0 ). recent articles in the New York Times and stories on ben85927_09_c09.indd 404 1/28/14 1:19 PM Su MMA rY & rES ourc ES National Public radio make clear just how bad air pollution conditions are in china ( http:// www.nytimes.com/2013/04/02/world/asia/air-pollution-linked-to-1-2-million-deaths -in-china.html and http://www.npr.org/blogs/health/2013/04/02/176017887/chinas - air-pollution-linked-to-millions-of-early-deaths ). these two web pages make use of satel - lite imagery to show just how bad air pollution is over china ( http://earthobservatory.nasa .gov/I ot D/view.php?id=80152 and http://www.chinaairdaily.com ). the EPA’s National Emissions Inventory can be found here ( http://www.epa.gov/ttnchie1/trends/).
the EPA’s National Pollutant Discharge Elimination System web page contains a lot of infor - mation on water pollution regulation and issues in the united States ( http://cfpub.epa.gov /npdes/ ). the u.S. Geological Survey also provides a lot of good information on water quality issues on its National Water-Quality Assessment web page ( http://water.usgs.gov/nawqa/).
though you may not want to know the details, you can learn more about what might be in your drinking water by visiting one of these sites (http://www.ewg.org/tap-water/ , http://water .epa.gov/drink/local/index.cfm/drink/local/index.cfm , or http://projects.nytimes.com/toxic -waters/contaminants ). Information on mercury pollution and how it gets into our food sys - tem and eventually our bodies can be found at these sites ( http://www.epa.gov/hg/, http:// grist.org/food/mercury-in-seafood-where-does-it-come-from/ , and http://www.scientific american.com/article.cfm?id=how-does-mercury-get-into ). this article from Nature maga- zine describes the problem of “acoustic pollution” and how it affects marine mammals (http:// www.nature.com/scitable/spotlight/acoustic-pollution-and-marine-mammals-\ 8914464 ).
A highly detailed review of how sanitary landfills are constructed and managed can be found here ( http://www.cedengineering.com/upload/An%20Introduction%20to%20Sanitary%20 Landfills.pdf ). the Story of Stuff Project takes a fascinating look at how our modern industrial system is designed in a way that promotes waste and environmental destruction (http://www.storyofstuff.org/ ). their videos Story of Stuff , Story of Electronics, and Story of Bottled Water are especially good at showing the environmental impacts of the produc- tion and disposal of so many products we use on a regular basis (http://www.storyofstuff .org/movies-all/story-of-stuff/, http://www.storyofstuff.org/movies-all/story-of-electronics/, and http://www.storyofstuff.org/movies-all/story-of-bottled-water/). A rather sad story of how massive volumes of waste are washing up on remote beaches in Alaska can be found here (http://e360.yale.edu/feature/carl_safina_gyre_tons_of_trash_covers_shore\ s _alaska/2668/ ). this EPA site provides a lot of good information on recycling, reduc - ing, and reusing ( http://www.epa.gov/osw/wycd/catbook/ ). A case for zero waste and how we might develop an economy that eliminates waste can be found here ( http://www .zerowaste.org/case.htm ). Lastly, this expert debate tackles the question of whether informed consumers can help the environment while they shop or whether “green consumerism” is a misguided attempt to get consumers to just buy even more ( http://www.nytimes.com /roomfordebate/2012/07/30/responsible-shoppers-but-bad-citizens ). ben85927_09_c09.indd 405 1/28/14 1:19 PM ben85927_09_c09.indd 406 1/28/14 1:19 PM