This study evaluated the acute toxicity of sodium selenate to two daphnid and three gammarid amphipod species. The daphnids, Ceriodaphnia dubia and Daphnia pulex, were evaluated in 48-hour static tests and the amphipods, Gammarus pseudolimnaeus, Gammarus lacustris, and Hyalella azteca, were evaluated in 96-hour static and flow-through tests. Tests resulted in mean LC50's of 1.92, 9.12, 1.82, 3.05, and 1.95 mg/L selenium for C. dubia, D. pulex, G. pseudolimnaeus, G. lacustris, and H. azteca, respectively. The LC50's for the G. pseudolimnaeus tests are more than 30-fold higher than previously reported LC50's for the same or similar species. The explanation for these differing results appears to be partially, but not entirely, explained by differences in ambient pH between the new studies and previous ones. Depending on how the new data are included in U.S. EPA's selenium freshwater quality criterion data set, the selenate acute water quality criterion (i.e., Criterion Maximum Concentration) increases from 12.8 to as high as 583 microg/L selenium.

This study reports concentrations of tributyltin in seafood collected from eight sites around the world and assesses potential human health risks. Samples of fish, crustaceans, cephalopods (i.e., squid), and bivalve molluscs were purchased from markets in two Asian cities, one Australian city, three European cities, and two North American cities. Samples were then analyzed for tributyltin, and the chemical concentrations observed were used to calculate potential human health risks from consumption of market-bought seafood. TBT residues in marketable seafood were consistent worldwide, averaging 185 ng/g dry weight. For different reasons, pelagic fish and bivalve molluscs tended to have slightly higher residues than squid, demersal fish (sole/flounder) and crustacea. TBT concentrations in seafood from France and Korea were at least twice as high as those from the other countries. Based on average per capita seafood consumption rates for each country, the amounts of TBT ingested did not exceed proposed thresholds for chronic effects, suggesting negligible risks to the average consumer.

Abstract-A site-specific marine water-quality criterion for cyanide was developed for Puget Sound, Washington, USA. The U.S. Environmental Protection Agency (U.S. EPA) national cyanide water-quality criterion is driven by toxicity data for the eastern rock crab, Cancer irroratus, a species not resident to the U.S. western coast (West Coast). The reported LC50 for C. irroratus is six times lower than any other marine species tested. Cyanide acute toxicity tests were conducted using first stage zoeae of all four species of Cancer spp. resident to Puget Sound to develop a site-specific criterion for this water body. Testing with Puget Sound Cancer spp. reveals sensitivities 24 times less, on average, than C. irroratus. Recalculation of the Puget Sound water-quality criterion for cyanide, by substituting the new Cancer spp. data for the C. irroratus data, results in water-quality criterion protecting marine life against acute and chronic toxicity of 9.4 and 2.9 g/L cyanide, compared to the U.S. EPA national value of 1.0 g/L for both acute and chronic toxicity.