Occurrence and distribution of HCHs and DDTs in surface water and groundwater from the Gajulamandyam region along the Swarnamukhi river basin, Andhra Pradesh, India

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ABSTRACT Organochlorine pesticides (OCPs) are growing concern and ubiquitous in the environment due to their chronic toxicity, persistence, bioaccumulation, and biomagnification properties. The concentration levels of selected organochlorine pesticides (OCPs) like HCH (hexachlorocyclohexane) isomers (α, β-, γ-, δ- HCH) and DDT (dichlorodiphenyltrichloroethane) family (p,p′ – DDT, p,p′ – DDE, p,p′ – DDD) and their distribution patterns in surface water and groundwater of the study area have been investigated. Gajulamandyam region has chosen as a study area that is lying on the banks of Swarnamukhi River basin in Andhra Pradesh, India. Water samples were extracted using the SPE procedure and determined using gas chromatography-mass spectrometer (GC-MS). Concentration profile of total HCH isomers in surface water and groundwater samples have ranged from n.d.- 2970 ng/L (mean 795 ng/L) and n.d.- 2150 ng/L (mean 649 ng/L) respectively. Similarly, the concentrations of ƩDDT in surface water in the range of n.d.- 2020 ng/L (mean 653.6 ng/L) and groundwater n.d.-1540 ng/L (mean 527.3 ng/L) had been observed. The concentration distribution of ƩHCH in surface water and groundwater varied significantly with different sampling sites that indicated their sources of contamination are diverse. The OCP residue levels, namely α – HCH/γ – HCH ratios in the water indicating that it might be from long historical to a recent mixed source of the technical grade of HCHs as well as lindane. Besides, the ratios of (DDE+DDD)/DDT metabolites reveal that the source of contamination may be due to technical DDT. The residue levels of DDTs found in this investigation signifying 63% of groundwater samples exceeded the WHO recommended drinking water limits, thereby affecting human health. The spatial distribution of OCPs demonstrated the variations in pesticide burden in water bodies. The present investigation on the occurrence of HCHs and DDTs in water has advantageous because it provides baseline data for the management of water resources.