Acute toxicity of trivalent thallium compounds to Daphnia magna

Daphnia magna was used to evaluate the aquatic toxicity of Tl(III) compounds including Tl(III) nitrate, Tl(III) chloride, and Tl(III) acetate. The results clearly show that Tl(III) is extremely toxic to daphnids. The 48-h LC50 values for Tl(III) nitrate, Tl(III) chloride, and T(III) acetate are 24, 6I, and 203 mu g/L, respectively. TI(III) is much more toxic than Tl(l) and many other metals such as Cd(II), Cu(II), and Ni(II); it is similar to the toxicity that of Hg(II). The formation of Tl(III)-complexes would significantly reduce TI(III) toxicity. (c) 2005 Elsevier Inc. All rights reserved.