Exposure Assessment 



Exposure assessment is the process of characterizing the human 

 populations exposed to the chemicals of concern, the environmental 

 transport and fate pathways of those chemicals, and the frequency, 

 magnitude, and duration of the exposure dose (U.S. EPA 1986b). For 

 exposure assessment of contaminated fish and shellfish, the following 

 factors should be considered: 



• Concentrations of contaminants in aquatic biota of concern 



• Potential environmental transfer of contaminants from sources 

 through aquatic species to humans 



• Fisheries harvest activities, diet, and other characteristics of 

 exposed human populations 



• Numerical variables (e.g., food consumption rate, contaminant 

 absorption efficiency) used in models to estimate exposure 



• Purpose of the exposure assessment (e.g., assessment of poten- 

 tial closure of sport or commercial fishery; documentation of 

 health risk from local contaminant sources such as hazardous 

 waste site or wastewater discharges; development of sportfish 

 consumption advisories). 



Information on contaminant concentrations and the exposed popula- 

 tion is combined to construct an exposure profile, which includes 

 estimates of average rates of contaminant intake by exposed in- 

 dividuals. Key stages of an exposure assessment for contaminated fish 

 and shellfish are discussed in the following sections. 



Measurement of 

 Contaminant 

 Concentrations in 

 Tissues 



Guidance on development of study designs to measure concentrations 

 of toxic substances in edible tissues of fish and shellfish is provided in 



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