Write a 3 pages paper on limitations in risk assessment. basis of limited information on chemical contamination and assumptions about thepopulation. Exposure assessments should not be based on a hypot

Write a 3 pages paper on limitations in risk assessment. basis of limited information on chemical contamination and assumptions about the

population. Exposure assessments should not be based on a hypothetical maximally

exposed individual (MEI). Screening risk assessments should rely on more representative

estimates. Risk-management decisions should be based on refined exposure assessments

that evaluate the distribution of a population's varied exposures and should address

explicitly for any segments of the population that have unusually high exposures.

Whenever possible, measurements should be obtained to support or validate any generic

values used in exposure assessments, to check modeling results, or to provide more-

realistic estimates of exposure than can be obtained with models. Such measurements

might include collecting data at locations where exposures are anticipated, monitoring the

exposures experienced by individuals, collecting data on the physical and chemical

conditions that affect the movement and availability of chemicals, and providing

information that relates exposure to effects, possibly using biologic markers.

Measurements of exposure can be very different from estimated exposures based on

source characteristics "(Risk Assessment and Risk Management in Regulatory Decision-

Making, 28)

There are two broad types of mathematical models used in exposure assessment: those

that predict exposure to the agent, and those that predict the concentration of the agent.

Exposure models can be used to estimate the exposures of populations based on small

numbers of representative measurements. Models that predict concentration can be

combined with information on human time-activity patterns to estimate exposures.