Screening levels spatial interpolation of lifetime carcinogenic risk by organochlorine pesticides across catchments of river chenab

Abstract

The present study has employed an advanced GIS based statistical technique for spatial interpolation of lifetime carcinogenic risk to OCPs in water and sediments from tributaries of River Chenab. The findings revealed that among all detected isomers, DDT exhibited the highest concentrations (mean 14.41 ng/l: range 9.33 – 20.21 ng/l and mean 16.47 ng/l: range 10.55 – 21.24 ng/g) for water and sediment, respectively. Results of OCPs fingerprints revealed the presence of dicofol confirmed fresh input of OCPs isomers along with the DDTs (Dichloro-diphenyl trichloroethane) historical usages in water bodies. The evaluation of ecological risk to benthic organisms’ fish, daphnia and green algae (RQ 2 × 10²) indicated that DDTs (DDD, DDE) pose potential hazardous risks (>1) to fish species across all the studied sites. Moreover, Spatial interpolation of the lifetime carcinogenic risk denoted the sites along downstream zone surpassed the permissible limit. The non-carcinogenic risk (∑HQ) ranged from 2 × 10^-3 – 1.0 with the highest value for DDT, indicating DDT as a potential hazard through oral exposure (∑HQ≥1). In the case of sediments results of SQGQs (Sediment Quality Guideline Quotient) levels for DDE (Dichloro-diphenyldichloromethane) and DDD (Dichloro-diphenyl dichloroethylene) denoted a severe biological risk to ecological integrities. The findings comprehend the more inclusive monitoring of OCPs usage and distribution in the studied region to reduce risks ecological integrities and to promote good health and wellbeing’s.