Premium
Comparative toxicity of cadmium, zinc, and mixtures of cadmium and zinc to daphnids
Author(s) -
Shaw Joseph R.,
Dempsey Thomas D.,
Chen Celia Y.,
Hamilton Joshua W.,
Folt Carol L.
Publication year - 2006
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1897/05-243r.1
Subject(s) - daphnia magna , cadmium , daphnia pulex , ceriodaphnia dubia , zinc , pulex , cladocera , ecotoxicology , toxicity , daphnia , toxicology , environmental chemistry , chemistry , acute toxicity , population , metal toxicity , biology , ecology , crustacean , demography , organic chemistry , sociology
Investigations were conducted to determine acute (48‐h) effects of cadmium and zinc presented individually and in combination on Ceriodaphnia dubia, Daphnia magna, Daphnia ambigua , and Daphnia pulex. Toxicity tests were conducted with single metals to determine lethal effects concentrations (lethal concentrations predicted for a given percent [ x ] of a population, LC x value). These were used to derive metal combinations that spanned a range of effects and included mixtures of LC15, LC50, and LC85 values calculated for each metal and species. In single‐metal tests, 48‐h LC50 values ranged from 0.09 to 0.9 μmol/L and 4 to 12.54 μmol/L for cadmium and zinc, respectively. For each metal, D. magna was most tolerant and showed a different pattern of response from all others as determined by slope of concentration–response curves. In the combined metal treatments, all daphnids showed a similar pattern of response when LC15 concentrations were combined. This trend continued with few exceptions when LC15 concentrations of cadmium were combined with LC50 or LC85 values for zinc. However, when this treatment was reversed (LC15, zinc + LC50 or LC85, cadmium), responses of all species except D. magna indicated less‐than‐additive effects. For C. dubia , a near complete reduction in toxicity was observed when the LC15 for zinc was combined with LC85 for cadmium. Multimetal tests with D. magna did not differ from additive. Collectively, these studies suggest that D. magna may not be representative of other cladocerans.