Assessment of mutagenic potential of thiram

Thiram is a widely used dithiocarbamate fungicide. In this study, the mutagenicity of thiram was investigated using the micronucleus and dominant lethal tests in Swiss albino mice. A single ip injection of 100 mg thiram/kg body weight, which is the maximum tolerated dose (MTD), significantly induced micronucleus formation in bone marrow cells after 30 and 48 hr of exposure; 50% and 25% of the MTD also induced micronucleus formation after the above time periods. A significant number of dead implants were induced when thiram was given to male mice in the diet at 10% of the oral LD50 during the whole spermatogenesis cycle (8 wk); this post-implantation loss indicates a dominant lethal mutation. (C) 1997 Elsevier Science Ltd.