References 



and is a very conservative (that is, a "protective") approach to 

 determining whether there are any significant public health risks 

 posed by specific chemicals' contamination of fish or shellfish in a 

 given area. In instances of contamination by multiple chemicals, 

 ERA'S 1 986 guidance recommends that the risk estimates from the 

 individual chemicals be added together to obtain the overall risk 

 assessment. This additive approach is neither conservative nor 

 non-conservative because in a few instances effects could cancel 

 one another out, while in others, effects could enhance one 

 another. But the overall risk assessment will remain conservative 

 because each of the underlying individual risk estimates was 

 conservative. 



United States Environmental Protection Agency. 1987. Draft 

 guidance manual for health risk assessment of chemically 

 contaminated fish and shellfish. Prepared for U.S. EPA, Of- 

 fice of Marine and Estuarine Protection, Washington, DC, 

 by Battelle Memorial Institute, Duxbury, MA, and PTI 

 Environmental Services, Seattle, WA. 



U.S. Environmental Protection Agency. 1986. Guidelines for 

 health risk assessment. Parts ll-VI. U.S. EPA, Washington, 

 DC. Federal Register, Vol. 51 , No. 185. pp. 33992-34054. 



U.S. Environmental Protection Agency. 1987. Integrated Risk In- 

 formation System Supportive Documentation, Volumes I 

 and II. EPA 16001 8-861 032a, March 1987. U.S. EPA, 

 Washington, DC. 



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