Abstract
Organochlorine pesticides (OCPs) are very hazardous and persistent compounds, endangering human health and the environment. This study reports the data analysis on profile distribution, residual level, ecological risk assessment, and soil-air exchange of OCPs in environmental compartments (water, sediments, soil, and air) of Uchalli and Khabeki Lakes. The samples were analyzed through GC-MS. Ʃ13OCPs in water, sediment, soil, and air of Uchalli Lake were in the range of 0.94-10.37 µg/L, 289.26-589.03 ng/g, 247.06-480.17 ng/g, and 3.31-168.65 pg/m(3), respectively. In contrast, the concentrations of Ʃ13OCPs in water, sediment, soil, and air of Khabeki Lake varied between 0.27 and 2.70 µg/L, 146.9-348.49 ng/g, 159.01-384.78 ng/g, and 187.43-1349.99 pg/m(3), respectively. Among all of the analyzed OCPs, the contamination of DDTs was highest across all matrices in both studied lakes. Independent sample t test showed highly significant variation (p < 0.01) of o, p'-DDE, p, p'-DDE, o, p'-DDD, o, p'-DDT, p, p'-DDT in water, p, p'-DDD in air, while cis-chlordane was found in the soil of both lakes. In contrast, sediments represent non-significant variation (p > 0.05) in the studied lakes. The principal components of PCA of Uchalli and Khabeki Lakes revealed 73.04% and 82.57% of the total variance, indicating strong association between the sources and distribution patterns of OCPs in environmental compartments. Moreover, HCHs and DDTs represent net volatilization from soil to the atmosphere of Khabeki Lake, with the fugacity fraction greater than 0.5. In contrast, the metabolites of endosulphan and chlordane displayed ff < 0.5, showing atmospheric deposition into the soil of Uchalli and Khabeki Lakes. All of the DDT metabolites in Uchalli Lake and the sole metabolite (o, p'-DDE) in Khabeki Lake were shown to pose a significant threat to the ecological integrity of the studied lakes, indicating a high risk with RQ > 1. This study suggests that exposed OCP stockpiles pose a danger and should be restricted until remediation to ensure the ecological integrity of Uchalli and Khabeki Lakes. Proper disposal of banned OCPs and strict enforcement of regulations are essential to prevent illegal use.