Awareness on pesticide residues in food crops: A challenge

Abstract

A review of field research conducted at the ICRISAT in collaboration with national partners to monitor the insecticide residues on food crops (rice, chickpea, maize, pigeon pea) and vegetables and the recent studies by other researchers in this field revealed the presence of residues of selected pesticides on crops. These include monocrotophos, chlorpyrifos, endosulfan, and cypermethrin. Only 3 % of the rice had beta endosulfan residues, while 35 % of tomato and 56 % brinjal had residues of these insecticides; however, only 4 % of the samples had residues above the maximum residue limits (MRLs). The crop samples analyzed (56) for pesticide residues in 15 contact (nonchemical pesticide group of 41 farmers) and 5 noncontact (15 samples) villages revealed the presence of pesticide residues in 21 samples above 0.001 ppm, except for two Dolichos bean and tomato samples which had residues of monocrotophos and chlorpyrifos above MRL. Though the residues in pulses were observed at harvest, they were below detectable levels after processing, i.e., thrashing and splitting the seed into dhal, indicating their safety in food chain; however, their haulms had insecticide residues. Fields under integrated pest management (IPM) showed substantial reduction in pesticide use across crops, which reflected in the occurrence of low residues. Twenty percent of brinjal and tomato samples had residues compared to 47 % in non-IPM fields. Though the contamination levels in crops in IPM and non-IPM fields indicated substantial differences, the residue concentrations were below MRLs indicating safety to beneficial arthropods.