Chlorothalonil is a widespread non-systemic fungicide used for the control of fungal infections in
agriculture of vegetables and fruits. Due to the widespread use of chlorothalonil, chlorothalonil
has been detected in all environmental systems, which poses potential risks to human health.
The genotoxic eff ects of the fungicide Chlorothalonil were analyzed in cultured human
peripheral lymphocytes by use of cytogenetic parameters including chromosomal aberrations,
sister chromatid exchange and mitotic index. Blood samples were obtained from two healthy
Non-smoker volunteers (aged 25 to 26 year old). Human lymphocytes were treated with four
diff erent concentrations of Chlorothalonil (1, 5, 20, and 50 µg/mL). The results of this study
showed that Chlorothalonil signifi cantly increased the frequency of chromosomal aberrations
and sister chromatid exchange compared to the negative control. Moreover, chlorothalonil
signifi cantly decreased the mitotic value at all concentrations. Current fi ndings show that
Chlorothalonil is clastogenic and induces in vitro DNA damage in human lymphocytes.