MERCURY CONTAMINATION STANDARDS 

 FOR MARINE ENVIRONMENTS 



RONALD EISLER 



Environmental Protection Agency, Environmental Research Laboratory, 



Narragansett, Rhode Island 



ABSTRACT 



Selected technical literature on biological and ecological effects of mercury 

 compounds on marine and estuarine biota is reviewed. Potential and actual 

 hazards to public health through marine vectors are considered. Within this 

 framework, approaches for establishing mercury contamination standards in 

 saline environments are presented. 



Toxicological aspects of mercury and mercury compounds in coastal 

 and offshore environments as a result of anthropogenic or natural 

 processes have been extensively reviev^ed elsew^here (D'ltri, 1972; 

 Friberg and Vostal, 1972; Gavis and Ferguson, 1972; Harriss, 1971; 

 Holden, 1973; Jemelov, Landner, and Larsson, 1975; Keckes and 

 Miettinen, 1972; Newberne, 1974). Most of these authorities agree 

 on five points. First, forms of mercury v^ith relatively low toxicity 

 can be transformed into forms v^^ith very high toxicity through 

 biological and other processes. Second, uptake of mercury directly 

 from seawater or through biomagnification in marine food chains 

 returns mercury to man in concentrated form. Third, mercury 

 uptake may result in genetic changes. Fourth, elevated levels of 

 mercury in some marine fishes, such as tuna or swordfish, emphasize 

 the complexity of both natural mercury cycles and man's impact on 

 those cycles. Finally, man's use of mercury should be curtailed 

 because, in contrast to some other pollutants, the difference between 

 tolerable natural background levels of mercury and harmful levels in 

 the environment is exceptionally small. 



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