Analysis of Pesticide Residues in Vegetables from Shenyang, China

Organ phosphorus pesticides (OPs) were first synthesized in large quantities in the 1940´s and are now widely used in China. Although OPs can degrade rapidly, they are also highly toxic. Indeed, many cases of poisoning in China, especially from vegetable sources, were attributed to the presence of OPs in large quantities. Even though the use of highly toxic pesticides in vegetables has been banned in China, in recent years high residual amounts of pesticides (mainly parathion and methamidophos) have been found in vegetable samples through routine monitoring efforts conducted by the Ministry of Agriculture. Hundreds of cases of acute poisoning resulting from the contamination of agricultural products with pesticides are now reported every year, posing a serious threat to the health of consumers and simultaneously leading to an increased level of awareness of the issue. In this study, we examine pesticide residue levels in vegetable samples (cucumber, celery, tomato, green pepper and eggplant) from four sources in Shenyang City. Our results show that OP levels in cucumber, celery and tomato samples were above the safe limits for consumption. Overall, samples from the larger supermarkets of Shenyang were safer than those from retailers and from the farmers´ market. Parathion was the most commonly detected residue. Omethoate, phorate and methyl parathion, currently prohibited due to their highly toxic nature, were also detected in some samples.