Cytogenetic study on individuals occupationally exposed to DDT.

Workers from three insecticide plants in direct contact with 2,2-bis (beta-chlorophenyl)-I,I,I,-trichloroethane (DDT) did not differ significantly in the frequencies of cells with chromosomal aberrations when compared with controls from the same plants but not in direct contact with the drug. The same was true when a group of workers from one plant was compared with a control group from the Instituto Butantan, with no history of occupational exposure to DDT. Yet, when the control group from one of the three plants, which showed high DDT plasmic levels, was added to the group in direct contact with the insecticide, the frequency of cells with chromatid aberrations was significantly higher, suggesting that DDT causes chromatid lesions. A positive correlation was found between DDT levels and times of exposure, but being in direct or indirect contact with DDT was not always correlated with the degree of contamination.