Detection of Pesticides Residues in Vegetables Raised under Protected Cultivation in Saudi Arabia.

Abstract

A market basket survey was conducted to monitor some pesticide residues on domestic vegetables (lettuce, cucumber, tomato, squash and cantaloupe) collected from different protected houses in three different regions of Saudi Arabia (i.e.EI-Riyadh, EI-Qassim and Tabuck) during Mar. 2002 to Feb. 2003. All samples were examined for a Multi- residues analysis of 36 pesticides, belonging to different functional groups such as insecticides, acaricides, fungicides and herbicides. Overall, 86.71 % of samples had no detectable pesticide residues, whereas of the contaminated samples, 13.29% contained detectable residues and 0.58% exceeded their maximum residue limits (MRLs). Data revealed that surveyed samples were contaminated with different levels of pesticide residues according to plant variety, type of pesticide and sampling season, whereas no clear relation was found between pes-ticide residues and sampling locations. A higher frequencies of pesticides positive samples were recorded with cucumber and tomato samples, while squash, cantaloupe pulp and lettuce samples came next in this respect. On the other hand the ma-jority of monitored residues were found in spring and summer seasons, whereas low or no occurrence frequencies of positive samples were achieved at autumn and winter seasons. In general organophosphorous insecticides were the most detected con-taminants on the tested samples. Almost all positive samples were found to contain residues of chlorpyrifos-methyl, pirimiphos-methyl and malathion insecticides. It is interesting to noticed that all monitored concurrently residues were not exceeding the Maximum Residues Limits (MRL) established by the Codex. Alimentarius Committee on pesticide residues with exceptions of Chlorpyrifos-methyl in lettuce and Heptachlor in cucumber.