Surveillance of pesticide residues in tomato and eggplant and assessment of acute and chronic health risks to the consumers in Pakistan

Abstract

Pesticide application has become a mandatory requirement of the modern agricultural system, resulting in the objectionable levels of pesticide residues in the treated food commodities and posing health threats to the consumers. This study aimed at optimization and validation of an analytical method which can be reliably applied for routine monitoring of the selected eighteen widely reported pesticides in tomato and eggplant. The principle of quick, easy, cheap, effective, rugged, and safe, i.e., QuEChERS, involving the acetate-buffered extraction followed by cleanup using the primary secondary amines (PSA) was employed. The analytical method was validated at three spiking levels (0.05, 0.01, 0.005 mg/kg) using gas chromatograph-micro electron capture detector (GC-µECD). Gas chromatograph-mass spectrometric detector (GC-MSD) was also used for confirmation and quantification using selective ion monitoring (SIM) mode. The method was applied on fresh samples of tomato (n = 33) and eggplant (n = 27) collected from local markets of Khyber Pakhtunkhwa, Pakistan, in the crop season 2020-2021. Twenty-five (76%) tomato samples and fifteen (56%) eggplant samples were found positive for one or more pesticides. Though the chronic and acute health risk assessments indicate that both of these vegetables are unlikely to pose any unacceptable health threat to their consumers, yet the risks from regular intake of pesticides-contaminated food commodities should be regularly addressed for possible protection of the public health and assurance of safe and consistent agro-trade, alike.

Keywords: Maximum residue limits; Method validation; Pesticides screening; QuEChERS extraction; Tomato and eggplant.