Hexaclorociclohexanos contamination in an urban area of South-Eastern Brazil

Abstract

A factory for producing the pesticide hexachlorocyclohexane (HCR) in its technical grade (mix of the a, b, g, and s isomers), that belonged to the former Institute of Malaria Sciences, then Ministry of Education and Health, located in the "Cidade dos Meninos", county of Duque de Caxias, State of Rio de Janeiro, was closed down in 1955. Part of its production and wastes - many tons this mix - were left behind on the site. The action of winds and rain as well as the movement of the local inhabitants - approximately 1,000 people, including 400 children, have caused the scattering of this agent. Blood speciments from the inhabitants showed high human contamination levels, with the highest concentrations (b isomers) being found in pelople living within a 100 meter radius of the ruin of the factory. Local soil and pasture samples taken at distances of less than 100 m from the ruin of the former factory showed HCH isomer concentrations of the order of thousands of ppb, thus providing evidence of high environmental contamination.