Acute Toxicity to Daphnia Pulex of Six Classes of Chemical Compounds Potentially Hazardous to Great Lakes Aquatic Biota

Abstract

Of the six classes of chemicals potentially hazardous to Great Lakes aquatic biota, derivatives of polyaromatic hydrocarbons (PAHs) were the most acutely toxic (48-h EC 50) to Daphnia pulex. The other classes, listed in order of decreasing toxicity, were alky I halides, nitrogen-containing compounds, cyclic alkanes, heterocyclic nitrogen compounds, silicon-containing compounds. Of the 41 compounds representing the six chemical classes, 6 were extremely toxic (> 0.01 – 0.1 mg/L), 11 highly toxic (> 0.1 – 1.0 mg/L), 20 moderately toxic (> 1.0 – 10.0 mg/L), and 4 slightly toxic (>10 – 100 mg/L). The reference compound, p, p′DDT, was super toxic (< 0.01 mg/L). Based on toxicity and relative abundance (hazard ranking) of the 21 compounds that were detected in tissue of Great Lakes fishes, the classes of compounds that present the greatest threat to Great Lakes aquatic biota are PAH derivatives, alkyl halides, and cyclic aklanes.