Uwe Borgmann1, Yves Couillard2, Patrick J. Doyle2, D. George Dixon3
1National Water Research Institute, Environment Canada, 867 Lakeshore Road, Burlington, Ontario, L7R 4A6, Canada
2Existing Substances Branch, Environment Canada, 351 Saint‐Joseph Blvd, Gatineau, Quebec, K1A 0H3, Canada
3Department of Biology, University of Waterloo, Waterloo, Ontario, N2L 3G1 Canada
Tóm tắt
Abstracthe toxicityofall atomically s able metals in the periodic table, excluding Na, Mg, K, and Ca, was measured in one‐week exposures using the freshwater amphipod Hyalella azteca in both Lake Ontario, Canada, and soft water (10% Lake Ontario). Metals were added as atomic absorption standards (63 metals), and also as anion salts for 10 metals. Lethal concentrations resulting in 50% mortality (LC50s) were obtained for 48 of the metals tested; the rest were not toxic at 1,000 μg/L. The most toxic metals on a molar basis were Cd, Ag, Pb, Hg, Cr (anion), and Tl, with nominal LC50s ranging from 5 to 58 nmol/L (1 to 58 nmol/L measured). These metals were followed by U, Co, Os, Se (anion), Pt, Lu, Cu, Ce, Zn, Pr, Ni, and Yb with nominal LC50s ranging from 225 to 1,500 nmol/L (88–1,300 nmol/L measured). Most metals were similarly or slightly more toxic in soft water, but Al, Cr, Ge, Pb, and U were > 17‐fold more toxic in soft water; Pd was less toxic in soft water. Atomic absorption (AA) standards of As and Se in acid had similar toxicity as anions, Sb was more toxic as the AA standard, and Cr and Mn were more toxic as anions. One‐week LC50s for H. azteca correlate strongly with three‐week LC50s and three‐week effect concentrations resulting in 50% reduction in reproduction (EC50s) in Daphnia magna.
