Tumourigenic studies on deltamethrin in Swiss albino mice

Deltamethrin, an alpha -cyano type II synthetic: pyrethroid insecticide is used to control a wide range of insects on a variety of crops. Deltamethrin is reported to cause many adverse effects on non-target species. Deltameth rin is reported to cause DNA damage and micronuclei induction in human lymp hocytes. It is: highly toxic for other organisms such as aquatic invertebra tes, fish and Daphnia. About the tumorigenic risk (both tumour initiating a nd promoting) associated with deltamethrin exposure. very few reports are a vailable in literature. in the present set of investigations, deltamethrin has been evaluated for its tumorigenic and co-carcinogenic (tumour initiati ng and tumour promoting) potential following long term dermal exposure in S wiss albino mice. The results revealed that deltamethrin has only tumour in itiating potential in both the sexes of Swiss albino mice, initiated with d eltamethrin and promoted by standard tumour promoter. 12-O-tetra decanoyl p horbol-13-acetate (TPA). In the single dose initiated mice (deltamethrin 4 mg/kg body weight, once only), 44%, males and 43% females developed benign skin tumours. A much higher incidence of tumorigenesis was recorded in mult iple dose initiated animals (deltamethrin 4 mg/kg body weight, three times per week for 3 weeks), where 71% male and 75% female mice developed tumours at the site of application of deltamethrin. Deltamethrin exposure failed t o show any tumour promoting and complete tumorigenic potential at all the t hree tested dose levels. (C) 2001 Elsevier Science Ireland Ltd, All rights reserved.