Organochlorine insecticides in drinking water in the city of Kraljevo [Serbia]

Organochlorine insecticides (OCI) belong to the group of chlorinated hydrocarbons with wide, but often uncontrolled, application in agricultural production. The consequence of this is that OCI and their residues are found in numerous examples in the ecosphere. Contamination of aquatic environments has been particularly emphasized. Although OCI are toxic substances for wildlife, especially for humans, a large part of the population is daily exposed to their activities in small quantities. OCI presence in drinking water is generally below the maximum allowable concentrations, whereas repeated doses can cause chronic toxic effects. For these reasons, it is necessary to continuously monitor the concentration of OCI in drinking water and perform its purification in order to obtain water with the lowest possible concentration. This work included the analysis of individual OCI concentration in drinking water in the city of Kraljevo. Individual concentrations of seven OCI have been measured: alpha-hexachlorocyclohexane (α-HCH), gamma-hexachlorocyclohexane (lindane), heptachlor, aldrin, dieldrin, endrin, dichloro-diphenyl-trichloroethane (DDT). OCI have been treated according to the appropriate EPA-608 methods, and then detected by gas chromatography method with the appropriate columns. The measured concentrations for individual OCI show significant increase in heptachlor, which is almost four times higher, and the concentration of aldrin, which is two times higher compared to the threshold limit values defined by the Regulation on Maximum Allowable Concentrations (MAC). Measured concentration of dieldrin is at the upper limit value of the MAC. Measured concentrations of endrin could not be discussed about because they are not regulated by the Regulation on MAC.Cumulative concentration of OCI in water from pumping station is 0.294 µg/l, which is in line with the maximum allowed concentration of 0.5 µg/l defined by the Regulation on the hygienic quality of drinking water. Given that only seven organochlorine insecticides have been analyzed in this paper, it is not surprising that the value of their overall concentration is unexpectedly high (over 50%). Total concentration of OCI presented in drinking water, especially measured increased concentrations of aldrin and heptachlor, indicate the processes of chemical contamination. For these reasons, it is necessary to continuously check the concentration of total and individual OCI in drinking water and take effective measures of water purification.