Banned DDT found in water samples in Andhra Pradesh: NGRI study

HYDERABAD: A research study by the city-based National Geophysical Research Institute (NGRI) has revealed the presence of banned organochlorine pesticides, DDT and HCH, in the water samples in Chittoor district of Andhra Pradesh.
Gajulamandyam region on the banks of Swarnamukhi river was chosen as the study area by the NGRI. Researchers found DDT residues in 63 per cent of groundwater samples in excess of the WHO recommendation for drinking water limits.This affects human health.

The study was published in the International Journal of Environmental Analytical Chemistry by NGRI scientists Rama Mohan Kurakalva and Keshav Krishna Aradhi. It gained significance in the wake of several research institutes finding organochlorides and organophosphates in samples in Eluru recently.
According to NGRI study, the concentration of HCH (hexachlorocyclohexane) was significant in all water samples. A metabolite of DDT (dichloro-diphenyl-trichloroethane) was found in 68.9 percent and 60.5 percent in surface water and groundwater respectively.
“Mean DDT residue levels in groundwater was found in the range of 527.3 ng/L. It exceeded in 63% of samples according to WHO guideline value of 0.001 mg/L for drinking purpose. Similar findings were reported on HCHs and DDTs in surface water and groundwater in other parts of India,” said NGRI scientists.
Researchers observed that that knowingly and unknowingly, people are still using HCHs and DDTs that were banned in India. The source of HCHs in surface water and groundwater might be due to the diverse agricultural practices. The present findings indicate that it is vital to develop a reliable monitoring system for organochlorine pesticide residues in water in order to assess any excess concentrations over environmental quality standards and to take appropriate action.
Organochlorine pesticides can impair the normal functioning of endocrine systems of human beings and animals The highest concentration levels of HCHs were found at the sampling points of Atturu and Papanaidupet area.
Researchers said locals might be using HCHs for agricultural and public health purposes. “Surface water bodies had an average concentration of DDT compounds at 1025 ng/L, 244 ng/L, and 692 ng/L DDE (dichlorodiphenyldichloroethylene, DDD (dichlorodiphenyldichloroethane), and DDT, respectively. The highest concentration levels of DDT was found in Atturu area suspected to be used for vector control purposes with commercial formulations.