Assessment of non-dietary human health risk based on concentration of multiresidue pesticides in soil of irrigated farmland around Lake Ziway, Ethiopia.

Soil samples collected from irrigated farmlands around Lake Ziway were thoroughly analyzed for 35 different pesticides, yielding significant insights into contamination profiles and the non-dietary health risks associated with these substances in the region. The analysis utilized gas chromatography-mass spectrometry (GC-MS) techniques. To assess non-dietary health risks, the study employed metrics such as the hazard index (HI) and Incremental Lifetime Cancer Risk (ILCR), considering various exposure pathways, including ingestion, dermal contact, and inhalation for both children and adults. The results revealed a concerning level of pesticide contamination in the agricultural soils of the area. Propargite was identified as the most prevalent contaminant, with a concentration of 62.463 ± 21.963 µg/kg, followed by p,p'-DDE at 46.85 ± 10.052 µg/kg. Other pesticides were detected at significantly lower levels. Risk estimates based on HI values indicated a non-carcinogenic risk for children and adults at 1.08E-02 and 1.35E-03, respectively, suggesting that the non-carcinogenic risk remains within acceptable limits (HI <1). The ILCR for children across all exposure levels, as well as for adults in terms of ingestion was found to be range from 1.59E-08-3.38E-16, suggesting that there is no significant cancer risk to humans through these pathways. However, the ILCRs associated with dermal contact for adults indicate a potential cancer risk, with estimates ranging from 10-4 to 10-6. Furthermore, model estimates indicate that adults face a greater cancer risk of non-dietary pesticide exposure compared to children. These findings highlight the urgent need for enhanced monitoring programs that address both currently used and banned pesticides.