| Summary: | Organochlorine insecticides (OCIs) are considered as one of the cost effective insecticides to provide quick impact on weed and pest control in agricultural application. The present investigation describes the spatio-temporal distribution pattern of OCIs and their concurrent environmental fate in surface soil samples collected from six provinces during monsoon and summer season from Palakkad district, the largest productive sector in the State of Kerala, India. The samples were analyzed to determine the residual levels of persistent OCIs (α-BHC (Cyclohexane), β-BHC, γ-BHC, heptachlor, aldrin, heptachlor epoxide (isomer B), 4,4′-DDE, dieldrin, endrin, 2,4′-DDD, 4,4′-DDD, 2,4′-DDT, 4,4′-DDT, α-endosulfan and β-endosulfan), by gas chromatographic technique using electron capture detector. The revealed results showed that the concentrations of ∑OCIs in soils of Palakkad ranged from non-detection to 150 ng g−1. The analysed samples mainly constitute endrin, followed by 2,4′-DDD, aldrin and γ-BHC. These xenobiotic residues could have resulted from the direct application into the soils and its persistent character in environment. These findings point out that their accumulation in the soil and risk of mobilization into the aquatic system would pose serious health hazards in the biota and in turn in the ecosystem. It was statistically interpreted that the sorption of OCIs in the soil matrix is influenced by the presence of organic matter, pH, temperature and the texture of the soil. The findings highlight the need of periodical monitoring of soil quality in and adjacent to the agricultural zones.
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