Pesticide residue in organic and conventional food-risk analysis

During the era of green revolution in the late sixties, introduction of high yielding varieties, expansion of irrigated areas, increased use of nitrogen, phosphorous, potassium (N, P and K) fertilizers; chemical pesticides and higher cropping intensity drove India toward self-sufficiency in food production. Use of chemical pesticides to control various insects, pests and diseases over the years destroyed many naturally occurring effective biological agents. Increased quantities of nutrients and pesticides in agricultural run off waters in recent years has caused serious problem of water pollution. The ill effects of green revolution include residues of extensively used chemical pesticides in various environmental components. Several studies showed that pesticides could cause health problem such as birth defects, nerve damage and cancer. Keeping in mind the problem of pesticide residues in various components of environment, the present study was conducted on different organic farms and market samples (conventional farms). Four groups of pesticides, i.e., organochlorine, carbamates, organophosphorous and pyrethrites were analyzed in wheat and rice samples. Presence of organochlorine pesticide residue was observed in two out of ten organic farms, which were converted from conventional to organic practices few years ago. This was attributed to excessive use of synthetic pesticides. Wheat and rice samples taken from market (conventional farm) showed significant level of pesticide residues. Method used for extraction of pesticides was validated with recovery studies, which showed more than 80% recoveries for organochlorine, organophosphorous, carbamates and pyrithroids, respectively. Pesticide residue contamination of food was assessed for risk analysis.