Analysis of cytogenetic damage induced in cultured human lymphocytes by the pyrethroid insecticides cypermethrin and fenvalerate.

Two pyrethroid insecticides, cypermethrin and fenvalerate, were tested for their ability to induce chromosome structural aberrations and sister chromatid exchanges in cultured human peripheral blood lymphocytes. Fenvalerate, but not cypermethrin, increased the frequencies of chromosome-type aberrations and sister chromatid exchanges. In addition, both pyrethroids affected the cell cycle causing a decrease in the proliferative rate index at concentrations greater than 10 micrograms/ml.