CHROMOSOMAL DAMAGE-INDUCED BY HERBICIDE CONTAMINATION AT CONCENTRATIONS OBSERVED IN PUBLIC WATER-SUPPLIES

Herbicide contamination of natural resources, specifically groundwater , has drawn considerable public attention in recent years, Although de leterious effects of herbicides at large dosages have been well docume nted, information is lacking about the possible effects of herbicide l evels that are found in public water supplies, Chromosomal damage is e xamined by Bow cytometry on Chinese hamster ovary (CHO) cells that are exposed to three herbicides (atrazine, simazine, and bentazon) at con centrations deemed safe by the U.S. Environmental Protection Agency (U SEPA) for drinking water, A known clastogen (ara-C) is also included a s a reference for comparing the magnitude of chromosomal damage caused by herbicides, Chromosomal damage was assessed by measuring the coeff icient of variation (CV) and percent chromosomes present in the larger chromosome distribution peaks, Exposure to atrazine hyl-N'-(1-methyle thyl)-1,3,5-triazine-2,4-diamine) increased the CV of the largest chro mosome distribution peak at concentrations considered safe by the USEP A. Chromosomes exposed to both simazine (6-chloro-N,N'-diethyl-1,3,5-t riazine-2,4-diamine) and bentazon -methylethyl)-(1H)-2,1,3-benzothiadi azin-4(3H)-one 2,2-dioxide) did not exhibit chromosomal damage, Furthe r analyses carried out on atrazine concentrations about equal to level s found in public water supplies revealed the potential of atrazine to induce chromosome breakages in CHO cells. Atrazine concentrations tha t were manyfold greater than the contamination limits exhibited a true clastogenic nature like ara-C, The results provide evidence for furth er investigations as to the potential health risk of consuming water c ontaminated with atrazine.