Human health risk assessment of pesticide residues in pointed gourd collected from retail markets of Dhaka City, Bangladesh

The increased level of pesticide residues in vegetables is a potential threat to human health, especially in children. In this study, human health risk assessment associated with the presence of pesticide residues in fresh pointed gourd (Trichosanthes dioica Roxb.) samples purchased from different markets of Dhaka City, Bangladesh, was done. Six selected organophosphorus pesticide residues (dimethoate, fenitrothion, chlorpyrifos, quinalphos, diazinon and malathion) in the samples were determined using modified QuEChERS extraction and gas chromatography coupled with flame thermionic detector. The method was validated by assessing the accuracy, precision, linearity, limit of detection (LOD) and limit of quantification (LOQ). The average recoveries of the selected pesticides ranged from 85 to 106% with precision in case of repeatability  ≤ 10% and combined uncertainty < 7 % in five fortification levels of 0.01 mg kg−1, 0.05 mg kg−1, 0.1 mg kg−1, 0.2 mg kg−1 and 0.3 mg kg−1. The linearity of the calibration curve was very good and the relative residuals were <  20 %. The LOD ranged from 0.002 mg kg−1 to 0.003 mg kg−1 and the LOQ was determined at 0.01 mg kg−1 for all the selected analytes. This method was applied successfully for the residue analysis of fresh pointed gourd samples. Among the analyzed samples, 8 (11.43 %) had pesticide residues, of which none had multiple pesticide residues. All of the contaminated samples contained residue above European Union-Maximum Residue Levels. Out of the eight contaminated samples, health risk was exceeded the acceptable value (< 1) in five for adults and seven for children associated with the residues of chlorpyrifos, quinalphos, diazinon and dimethoate. This finding reveals the public health concern due to potential of pesticide toxicity in vegetables for the consumers. Therefore, continuous monitoring on the use of pesticides in vegetables should be strengthened.