Comparative acute systemic toxicity of sodium arsenite and dichloro(2-chlorovinyl)arsine in rabbits

The acute intravenous toxicity of sodium arsenite and dichloro(2-chlorovinyl)arsine (lewisite) has been compared in rabbits to provide a quantitative and qualitative model for future assessment of treatments of lewisite poisoning. The LD50 of sodium arsenite was 7.6 mg.kg-1; that for lewisite was 1.8 mg.kg-1. On the basis of arsenic content the former was 6.5 times less toxic than the latter. Significant differences in tissue arsenic content and pathology were found between the 2 materials. Histologically, changes were observed in the lungs and gall bladder after lewisite injection but not after sodium arsenite. It was concluded that use of sodium arsenite is not a suitable substitute model for lewisite poisoning.