Exposure Assessment: Definition and Models - According to the EPA

To me, the most interesting of the four stages of quantitative risk assessment is Exposure Assessment. This is the one area that would be of most importance to the general public. The common citizen is curious to know how an assessment and especially a risk assessment will effect either themselves or their families. Human exposure assessment is another area under the general term of 'Exposure Assessment' of which I find intriguing. This may be useful for upcoming posts!!

Upon further investigation on Exposure Assessment, I found some useful information from the United States Environmental Protection Agency (EPA).

ELEMENTARY DEFINITION:

First, for a baseline lets find an easy to understand definition of Exposure Assessment: "Exposure Assessment is the process of estimating or measuring the magnitude, frequency and duration of exposure to an agent, along with the number and characteristics of the population exposed. Ideally, it describes the sources, pathways, routes, and the uncertainties in the assessment." (Wikipedia, 2009) I understand that alot of the academic population frowns upon using Wikipedia, however I find that the definitions on Wikipedia are easy to understand.

Exposure Assessments are also used for determination of...

- what happens to chemicals when they are used and released to the environment

-how workers, the general public, consumers and the aquatic ecosystems may be exposed to chemicals.

MODELS:
The EPA Center for Exposure Assessment Modeling (CEAM) was established to meet the scientific and technical exposure assessment needs of the EPA as well as state environmental and resource management agencies. CEAM provides proven predictive exposure assessment techniques for aquatic, terrestrial, and multimedia pathways for organic chemicals and metals.

The four assessment models that the CEAM uses are found below...

Groundwater Models:

Groundwater models quantify the movement of subsurface water and provide inputs to subsurface contaminant transport models. Simulation provides insight into groundwater and contaminant behavior and quantitative assessments for environmental decision making.

Surface Water Models:

By modeling contaminant movement and concentration in lakes, streams, estuaries, and marine environments, researchers can better understand how exposure to contaminants affects aquatic environments.

Food Chain Models:

Contaminated aquatic and terrestrial environments typically result in the bioaccumulation of chemicals within all trophic levels of an ecosystem. Software models provide tools for tracking the movement of contaminants through food chains and for estimating chemical impacts on exposed biota.

Multimedia Models:

Contaminants may travel through the atmosphere, soil, surface water, and the organisms that inhabit these media. The multimedia approach to exposure modeling quantifies the impacts of contaminants as they travel through more than one of these environments.

Source:

(U.S. Environmental Protection Agency, Exposure Assessment Models, http://www.epa.gov/ceampubl/)