Acute toxicity of thallium and indium toward brackish-water and marine organisms

We examined the toxic effects of thallium and indium on brackish-water and marine species. Acute toxicity tests were conducted on Americamysis bahia, Brachionus plicatilis, Artemia salina, and Sillago japonica. The LC₅₀ values of thallium ranged from 3.48 to 100mg/L, and this metal exhibited the strongest toxic effects on A. bahia. With regard to indium toxicity, the LC ₅₀ values ranged from 24 to 51 mg/L, and the strongest toxic effects were noted in B. plicatilis. The toxicity of thallium is higher than that of other rare metals toward both freshwater and marine species. Further, we examined the effects of salinity on thallium and indium toxicities toward A. salina. We found that the survival rates of A salina individuals following exposure to thallium or indium were strongly influenced by the salinity of the medium. The 48-h LC₅₀ of these metals decreased as the salinity of the medium decreased.