Skip to main content

Exposure Assessment

EXPOSURE ASSESSMENT

The field of exposure assessment has its origins in industrial hygiene. It has evolved rapidly since 1980, and is now used to examine personal contacts with toxicants found in the personal or community environments. The accurate characterizations of exposure to toxic agents can lead to identification of the distribution of exposure and determination of the mean and high-end values, all of which are central to effective risk assessment. The science to conduct exposure analyses and assessments can be placed within a continuum that follows the movement of a toxicant from its source, through to an ultimate health effect. Information on human exposure provides a firm scientific link between the information obtained by traditional environmental sciences, which focus on effluents, and health effects that can result from contact with environmental toxicants. Understanding and interdicting specific pathways for contact are essential in protecting the public health and the environment.

An exposure is defined as "an event consisting of contact at a boundary between a human and the environment at a specific contaminant concentration for a specified interval of time" (National Research Council). Understanding total exposure requires that its fundamental variables of concentration and time are summed over all possible microenvironments where people spend their time.

The data collected to complete an exposure assessment requires both indirect and direct measurements techniques. Direct measurements assess a person's exposure, using monitors attached to the individual, or through the sampling of biological media such as blood or urine. Indirect measurements involve collecting information about where, when, and how people spend their time, and about the concentrations of a contaminant associated with a medium that contributes to important routes of exposure. The data from indirect measurements are used to estimate a person's exposure using both simple and complex models. Detailed exposure and dose analyses frequently use a combination of direct measurements.

Theoretical advances for simulating exposure occurred in the early 1990s, contributing to an understanding of integrated multimedia and multiroute exposures and helping provide initial estimates of exposure within the general population and high-exposure subgroups. All modeling activities, however, must be validated by measurements.

The construction of models of individual or population exposures to contaminants is essential, since it is nearly impossible to measure all exposures experienced by an individual or by the general population. Therefore, statistically representative groups are selected from the population, and measurements from these groups are used to estimate the exposure of the population, using deterministic or fundamental models.

Exposure assessment is particularly pertinent to understanding risks associated with environmental hazards. Risk is a function of both hazard, which is intrinsic to the chemical or physical agent, and the intensity of a person's or population's exposure. Failure to pay attention to specific conditions within a community (e.g., consumption of homegrown vegetables) can lead to either underestimating risk. Community studies focus on measuring or estimating exposure of susceptible populations and of individuals or populations with the highest levels of exposure.

Paul J. Lioy

(see also: Pollution; Risk Assessment, Risk Management; Safety Assessment; Uncertainty Analysis )

Bibliography

Georgopoulos, P., and Lioy, P. J. (1994). "Conceptual and Theoretical Aspect of Exposure and Dose Assessment." Journal of Exposure Analysis and Environmental Epidemiology 4:253285.

Lioy, P. J. (1999). "Exposure Analysis: Reflection on Its Growth and Aspirations for Its Future." Journal of Exposure Analysis and Environmental Epidemiology 91:273281.

Lioy, P. J; Detels, R.; Holland, W. W.; McEwen, J.; and Omenn, G. S. (1997). "The Analysis of Human Exposure to Contaminants in the Environment." In Oxford Textbook of Public Health, 3rd edition, ed. R. Detels et al. Oxford, UK: Oxford Medical Publications.

National Research Council (1994). Human Exposure Assessment for Airborne Pollutants: Advances and Opportunities. Washington, DC: National Academy Press.

Ott, W. R. (1995). "Human Exposure Assessment: The Birth of a New Science." Journal of Exposure Analysis and Environmental Epidemiology 5:449472.

Zartarian, V. G.; Ott, W.; and Duan, N. (1997). "A Quantitative Definition of Exposure and Related Concepts." Journal of Exposure Analysis and Environmental Epidemiology 7:411438.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Exposure Assessment." Encyclopedia of Public Health. . Encyclopedia.com. 13 Dec. 2018 <https://www.encyclopedia.com>.

"Exposure Assessment." Encyclopedia of Public Health. . Encyclopedia.com. (December 13, 2018). https://www.encyclopedia.com/education/encyclopedias-almanacs-transcripts-and-maps/exposure-assessment

"Exposure Assessment." Encyclopedia of Public Health. . Retrieved December 13, 2018 from Encyclopedia.com: https://www.encyclopedia.com/education/encyclopedias-almanacs-transcripts-and-maps/exposure-assessment

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.