Pesticide residues on vegetables pose food safety concerns. In this study, an assay called the Rapid Bioassay for Pesticide Residues (RBPR) was utilized to screen large number of vegetable samples (n = 443) from various markets and stalls in selected areas in Southern Luzon, Philippines from January 2016–March 2018. RBPR is an enzyme-based assay that quickly detects toxic and commonly used insecticides, namely, organophosphates and carbamates in samples. Vegetable samples include both organic-labeled and conventional commodities. Analyzed samples with >20% enzyme inhibition were considered positive for synthetic chemicals. Results show that 15.8% of all the samples were positive for pesticide residues. Vegetable stalls from Laguna and Quezon, and Laguna public markets got the highest positivity of samples. Based on the farming method, 18.3% were positive in the conventional samples, as compared to 12.2% in the organic-labeled samples. Positivity rate was observed to be highest in bitter gourd, pechay, and tomato. A few samples (n = 6) were then analyzed by gas chromatography–mass spectrometry (GC-MS) to confirm RBPR results. One organic-labeled sample was found to have exceeded the existing maximum residue limits based on GC-MS analysis. Overall, the study showed the presence of pesticide residues in commonly consumed conventional and even organic-labeled vegetables in Southern Luzon. The positivity of many organic-labeled samples is of serious concern as it may indicate fraud or mislabel and non-compliance with principles of organic farming. This also highlights the critical need for extensive intervention strategies to limit the potential health risk to consumers.

Read the full article: 10.56899/151.03.05