t Thiocyclam (trade name Evisect) is a broad-spectrum nereistoxin analogue insecticide
used widely for agricultural applications. The aim of this investigation was to determine its genotoxic
effects in the chromosome aberration (CA) test and determining of mitotic index (MI), using
lymphocytes from peripheral blood samples of healthy human donors. A negative and a positive
control (MMC) were also included. Chromosomal analyses of the metaphase plates of the samples
treated with 14 different concentrations (from 0.1 to 120 lg/ml) of thiocyclam, indicating the lack
effect on chromosomes. Thus thiocyclam is not genotoxic but highly toxic on cell proliferation in
human lymphocytes.