Determination and evaluation of pesticide residues in vegetables using gas chromatography-mass spectrometry

This study aimed to determine and evaluate the pesticide residues (mg kg-1) in the most commonly consumed vegetables and their health risk assessment in Ahvaz City, southwest Iran, in 2022. Gas-chromatography-mass spectrometry (GC-MS) was employed to analyze and identify the presence of pesticide residues in the vegetable samples. The analysis of pesticide residues in the vegetable samples revealed the presence of fifteen pesticides, including commonly used insecticides from the organophosphate class. In some samples, the levels of pesticide residues exceeded the national MRLs. Most pesticides' calculated hazard index (HI) was below 100, indicating a lower risk of adverse health effects. However, in the case of oxydemeton-methyl in tomatoes, the HI was found to be 190, suggesting a higher potential for health risks. The cumulative risk index of pesticide residues, measured as the pesticide toxicity index (PTI), was determined for tomatoes, cucumbers, and potatoes by GC-MS (recovery of more than 95%). The PTI values were 15.2, 11.7, and 12.6, respectively, which exceeded the standard value of 1. This indicates that long-term consumption of these vegetables containing various pesticide residues may pose a chronic health risk to humans. While most pesticides had a relatively lower risk of adverse health effects, the elevated PTI values in all three vegetable types indicate a potential chronic health risk associated with the long-term consumption of these contaminated vegetables. Sample preparation and determination of pesticide residues in vegetables by GC-MS helps continuous monitoring to maintain the safety and quality of vegetables in the local market.