Situation of Pesticide Contamination in Vegetables and Fruits Sold in Thailand

Abstract

Pesticides are widely used in agriculture and can be harmful to human health. In developed countries, maximum residue limits (MRL) for vegetables and fruits are well established to protect consumers’ health. In Thailand, MRL has been promulgated but not well implemented. The aim of this review is to determine the presence and severity of pesticide contamination/residues in vegetables and fruits in Thailand. It also provides information on how to minimize the risks from these pesticide residues/contamination. Findings from the project entitled “Food safety in Thailand” conducted by Mahidol University, were presented. Various vegetables and fruits were randomly purchased from different markets, and tested for pesticide residues using the Gas Chromatography Mass Spectrometer (GC-MS) method. During the first 4 years (2016-2020) of the project, we monitored 9 varieties of vegetables and 14 varieties of fruits. We found that there were considerably contamination with pesticide residues in the vegetables and fruits studied. The occurrence of pesticide detection ranged from 57% in salad vegetables to 100% in many vegetables and fruits, e.g., cabbage, orange, and guava. The study also revealed that large numbers of the produce sold domestically were of low quality, since there were high pesticide residues at levels exceeding the Thai MRL. For example, the incidence of exceeding MRL was 100% for cabbage, 99% for orange, and 81% for tomato. Watermelon and durian could be safe as they contained pesticide residues below the MRL. Pesticide residues did not differ between produce sold in supermarkets and those sold in fresh markets. Ways and means to minimize risks associated with harmful pesticide residues in vegetables and fruits, such as, thorough washing, cooking and peeling of vegetables and fruits have been demonstrated in the literature. In conclusion, this review provided evidenced-base information to demonstrate that pesticide residues contamination in vegetables and fruits in Thailand were significant and could be an important public health problem. It is strongly recommended that Thai government authorities implement an effective routine pesticide residues surveillance program to monitor pesticide residues in domestic produce to curb the potential health risk to Thai consumers.