Robert A. Drummond

Cough Response and Uptake of Mercury by Brook Trout, Salvelinus fontinalis, Exposed to Mercuric Compounds at Different Hydrogen-ion Concentrations

Abstract The lowest concentration of methylmercuric chloride (MMC) and mercuric chloride added to Lake Superior water that caused a significant increase in cough frequency in brook trout was 3 μg Hg/liter. Cough frequency is a good short-term indicator of the long-term effects of MMC. The response can be used to predict the safe concentration of mercuric chloride since the long-term effects of this compound are not known. Increases in cough frequency were proportional to the concentration (from 3 to 12 μg Hg/liter) of both compounds at pH 7.5. The fish were more responsive to MMC when the pH of the test water was lowered to 6.0; response to mercuric chloride was not changed by lowered pH. Fish exposed to MMC at pH 6.0 contained more total mercury in their gills and red blood cells than fish tested at pH 9.0. The uptake of mercury by brook trout exposed to mercuric chloride did not differ significantly at pH 6.0 and 9.0.

Fish cough response—a method for evaluating quality of treated complex effluents

Abstract Bluegill sunfish ( Lepomis macrochirus ) showed increases in cough frequency commensurate with effluent concentration when exposed for 24 h to different industrial and municipal effluents. Effluents known to be toxic caused steadily increasing cough rates in the fish as effluent concentration approached acutely toxic levels. Bluegills exposed to three different samples of effluent, collected from the same source over an 8-month period, showed decreased levels of cough rate as the effluent improved in quality. Cough frequency is a rapid and sensitive physiological characteristic for evaluating the quality of industrial and municipal effluents and variation in quality of same-source effluents before discharge into receiving waters.

Predicting modes of toxic action from chemical structure

CHRISTINE L. RUSSOM,*y STEVEN P. BRADBURY,z STEVEN J. BRODERIUS**,y DEAN J. HAMMERMEISTER,y ROBERT A. DRUMMOND**,y and GILMAN D. VEITH**y yUS Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division, Office of Research and Development, Duluth, Minnesota, USA zUS Environmental Protection Agency, Office of Pesticide Programs, Office of Chemical Safety and Pollution Prevention, Washington, DC, USA