Assessment of organochlorine pesticides and health risk in tobacco farming associated with River Barandu of Pakistan

Diffuse pesticide pollution through tobacco fields is a serious threat to both natural integrities and living beings because tobacco is known as a pesticide-intensive crop. Upsurge in the knowledge of detrimental impacts caused by organochlorine pesticides (OCPs) has made them a burning issue particularly in developing countries. Pakistan is a country famous for its agro-based economy and simultaneously is the second most significant pesticide consumer in South Asian countries. The studied area is tobacco hub of the country. Thus, the present work is aimed to investigate the contamination profile that highlights the ecological and health risk posed by OCPs in River Barandu, located in the proximity of tobacco farming region. sigma OCP levels in sediments ranged between 32.918 and 98.810 ng/g and in water between 0.340 and 0.935 mu g/L. Hexachlorocyclohexanes (HCHs) and heptachlor were the most prevailing pesticides in both matrices of the river. Isomeric composition of DDTs and HCHs highlighted that the beta-HCH and p,p'-DDT were dominant isomers in water, while alpha-HCH and p,p'-DDT in sediment compartment. Enantiomeric compositions of HCH and DDT indicate both recent and historic uses of these compounds in the area. Indirect contamination through nearby tobacco clusters has been depicted through spatial analysis. Ecological risk assessment based upon the risk quotient (RQ) method revealed that alpha-endosulfan, dieldrin, heptachlor, and n-ary sumation HCHs represent a very high level of ecological risks. The OCPs' lifetime carcinogenic and non-carcinogenic health risks associated with dermal exposure to river's water were considered nominal for surrounding populations. However, detailed ecological and health risk studies are recommended considering the bio-accumulating nature of these contaminants in the food chain.

Automated summary

The study uncovered organic chlorine pesticide contamination in River Barandu near tobacco farming areas in Pakistan, with HCHs and heptachlor being the most prevalent. OCP levels in sediments ranged from 32.918 to 98.810 ng/g and in water from 0.340 to 0.935 μg/L. It is recommended to conduct detailed ecological and health risk studies considering the bio-accumulating nature of these contaminants in the food chain.