HYDERABAD: If the adage ‘you are what you eat’ is true, Hyderabadis stand the risk of exposure to lethal pesticides in the vegetables they consume. A study carried out by the National Institute of Nutrition (NIN) has found that pesticide residues in some of the vegetables and fruits sold at Rythu Bazaars or by street vendors are above the internationally stipulated maximum residual levels (MRL).
Green grapes and okra (lady’s finger) are the most contaminated. The NIN study analyzed fruits and vegetables sold by Rythu Bazars and street vendors in five zones in Hyderabad: Erragadda, Kukatpally, Mehdipatnam, Falaknuma and Lal Bahadur Nagar. It assessed residual pesticide levels in egg plant (brinjal), cauliflower, okra, tomato and chilli among vegetables, and grapes and apples among fruits.
The study found that green grapes, for instance, had residues of 18 pesticides, of which five were present in all the samples analyzed. The mean concentration of imidacloprid— a pesticide rated by WHO as moderately toxic to mammals— in green grapes was found to be 0.702 mg per kg whereas the acceptable MRL for spraying it is 1 mg per kg. Among the vegetables studied, okra too registered the presence of 18 pesticides of which 11 were present in all samples.
The study, reported in the journal Food Research International, also found that pesticide residue levels were higher than those reported by similar studies published earlier. The concentration of organophosphates was found to be especially high in the vegetable samples.
“This class of pesticides can cause neurotoxicity upon prolonged exposure which would result from consumption over some 20 years,” said Dr S N Sinha of NIN’s Food and Drug Toxicology Research Centre, who conducted the studies.
The main reason for the high residue levels is the unregulated use of pesticides by farmers who have no guidance on the permissible limits, says Dr Sinha.
India does not have in place a protocol of MRLs for all the pesticides used by farmers. So far, MRLs have been set for only 185 of the 815 molecules included in the schedule to the Insecticide Act, 1968. The study therefore relies on limits set by the Food and Agriculture Organization and World Health Organization (WHO).
“There are several banned pesticides farmers continue to use as they are unaware of proper limits. Further, farmers rely on information given by unqualified retailers on the choice of pesticides and their dosage,” said Dr Sinha.