Small scale and large scale farmers around Lusaka, the capital city of Zambia grow vegetables using intensive agriculture methods to satisfy the ever increasing demand. To ensure maximum yield farmers apply various types of pesticides to control pests and diseases that attack these vegetables. Organophosphate pesticides are widely used in agriculture for the control of various insect pests mainly in developing countries. The purpose of this study was to determine the residual levels of the most commonly used organophosphate, 2, 2-Dichlorovinyl dimethyl phosphate (Dichlorvos), in three common vegetables supplied at various study sites around Lusaka.
Samples of rape, lettuce and cabbage were randomly picked from the study sites around Lusaka. The vegetables were chopped into small pieces which were chemically treated to get methanol extracts. The extracts were then dissolved in an appropriate solvent and using Shimadzu High Performance Liquid Chromatography-Ultra-violet detector, levels of dichlorvos were determined.
The results of analysis showed that the levels of dichlorvos were significantly above the maximum accepted limit as set by Zambian Food and Drugs Act on vegetables. This higher than acceptable levels of dichlorvos may have implications on human health as the cumulative effect of organophosphates in human body has potential to cause long term health problems (Mackenzie Ross et al., 2010
