Appraisal of Dichlorvos Residues in the Regularly Consumed Food Items of the Calabar City, Nigeria: A Health and Safety Evaluation
Julius U. Naku
*
Department of General Studies, College of Health Sciences, Management and Technology, Calabar, Nigeria.
Bassey I. Inah
Department of Pure and Applied Chemistry, University of Calabar, Nigeria.
Peter E. Idaka
Department of General Studies, College of Nursing Sciences, Itigidi, Nigeria.
Aliyu Adamu
Department of Medicinal Plant Research and Traditional Medicine, National Institute for Pharmaceutical Research and Development, Abuja, Nigeria.
Paul T. Ugosor
Department of Chemisry, College of Education Katsin-Ala, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Background: Dichlorvos is a widely used organophosphate insecticide in crop and postharvest protection, but its high toxicity poses serious risks to human health and food safety, particularly in developing countries.
Aim: The study aimed to evaluate the presence and concentration of dichlorvos residues in regularly consumed food items and compare the results with established safety standards. It assesses the degree of public compliance with the campaigns against the use of dichlorvos for food preservation.
Study Design: Samples A, B, and C representing three commonly consumed food items; stock fish (Gardus morhua), beans (Phaseolus vulgaris) and bush mango (Irvingia gabonensis) respectively were bought randomly from the two major markets in the City of Calabar.
Place and Duration of Study: This research was carried out in the Petroleum Technology Development Fund (PTDF) laboratory of the Chemistry Department, University of Calabar, for ten months.
Method: Homogenized samples (2 g of each) were weighed into a conical flask and mixed with 15 mL of a mixture of acetone and ethanol in the ratio of 1:1 and blended. The mixture was centrifuged at 2500 rpm for 5 minutes. The supernatant was collected thrice from each sample and reduced in a rotary evaporator to 5 mL, which was used for GC-MS analysis.
Results: Only sample A showed the presence of dichlorvos while Samples B and C were not within detection limits. These results show that from the food commodities bought, only stockfish had detectable concentration (0.021mg/kg) of dichlorvos, which is above the acceptable limits of 0.01mg/kg (Chinese standard), 0.0144mg/kg (USEPA), but below the European Union limit of 0.05mg/kg.
Conclusion: Overall, the findings suggest a positive impact of regulatory interventions in Nigeria, reflecting a gradual reduction in dichlorvos usage in food preservation. The presence of dichlorvos in stockfish stresses the need for continued effort in pesticide regulation and consumer education, as improper use of pesticides still poses a health risk.
Keywords: Dichlorvos, pesticide residues, food safety, Calabar, health concerns, food preservation.