果品中有机磷农药联合毒性研究进展

Research progress of combined toxicity induced by organophosphorus pesticides in fruits

果品中的农药残留问题一直是果品质量安全工作中关注的重点,有机磷农药作为目前果树种植中应用最广泛的一类农药,在防治果树害虫方面占据重要地位。然而有机磷农药具有神经毒性、遗传毒性、免疫毒性、生殖发育毒性等多种潜在毒性,大量使用可能会在果品和环境中产生残留,通过环境和饮食进入人体后会对人体健康造成极大威胁。此外在果树种植过程中,往往复配或同时混合使用多种不同的农药,农药混合物的联合毒性值得引起人们更多的关注。文章归纳了有机磷农药对人体健康的影响、农药混合物的联合作用模式和评价方法,重点综述了不同实验模型在有机磷农药联合毒性中的应用和国内外研究进展,以期为今后果品中农药残留混合污染物风险评估提供相关参考依据。

With the continuous improvement of quality of life, people concern nutrition ana neatm more and more. The proportion of fruits on agricultural production and consumption is gradually increasing for its rich nutrition. And people has higher requirement for fruit quality and safety. In the process of fruit tree planting, people often use a variety of pesticides to control the disease, insects and pests. The protective effect of pesticides on fruit trees is worth affirmation. But pesticides have neurotoxicity, genotoxicity, immunotoxicity, reproductive and developmental toxicity, and other potential toxicity. Using high dose of pesticides can produce residue in the environment and fruits. It will enter the body through diet and cause great threat to human health. The pesticide residue in fruits has always been the focus on fruits quality and safety. In order to reduce the resistance of pests and achieve better control effect, people usually used compound pesticides or used different pesticides simultaneously in the process of fruit tree planting. This leads to that food products such as fruits may simultaneously contain residues of several different pesticides. It was also found in the actual detection that two or more kinds of pesticide residues can be detected in a fruit sample. As a result, the human body exposure to the complex mixtures of pesticides unavoidably through diet and environment. However current risk assessments of pesticide residues in fruits at home and abroad are mostly based on single pesticide toxicity evaluation. China has established some pesticide residue detection technologies for citrus, apples and other fruits. But the formulation of the standards about maximum residue limits for pesticides is limited to single pesticide. In fact, although a single pesticide may be limited within a standard, a variety of low dose pesticides exposure at the same time can bring harm to human body, increasing or decreasing the toxicity of each other and leading to a combined effect different from the single toxicity. According to the targets and mechanisms of the different components in the pesticide mixture, the combined effect mainly includes the following three modes： additive action, independent action and interaction. When the several kinds of pesticides in mixture have the same target and the similar action mechanisms, their combined toxicity effect presents additive action. When the several kinds of pesticides in mixture have the different targets and action mechanisms, their com- bined toxicity effect presents independent action. When the several kinds of pesticides in mixture have the same target and their action mechanisms may influence each other, their combined toxicity effect presents interaction. And this interaction is called synergism or antagonism respectively as the combined toxicity is stronger or weaker. The combined toxicity of pesticide mixture can be predicted by CA （concentration addition）, IA （independent addition） and CI （combination index） methods. Organophosphorus pesticides are widely used as insecticides on citrus, apple and other fruit trees. It is also the first group of pesticides to carry out joint exposure risk assessment in many countries and organizations. Organophosphorus pesticides are often used with pyrethroid and carbamate insecticides. Because they are all typical nerve poisons, having the same target organ and similar toxicity mechanism. Therefore, the combined toxicity of organophosphorus pesticides includes the joint toxicity effect induced by several organophosphorus pesticides and the joint toxicity effect induced by organophosphorus with pyrethroid or carbamate pesticides. Consequently, using genomics, proteomics and metabolomics methods to analyze the interaction patterns and the toxicity mechanisms between different pesticides, and then carrying out research of combined toxicity induced by organophosphorus pesticide mixtures in fruits have great important significance. This will not only provide the toxicological basis for the formulation of the standards about maximum residue limits for pesticide mixtures and risk assessments of organophosphorus pesticide residue mixtures in fruits in the future. When evaluating the combined toxicity of pesticide mixtures, in-vivo and in-vitro experiments can be used. In-vivo experiments commonly use mammals and aquatic animals as experiment models such as rats and fish. Most of the experimental animals have similar physiology, pathology and pharmacology metabolism to human, the results can be extrapolated to human. So the traditional studies on combined toxicity of organophosphorus pesticide mixtures mostly use living animals as experimental model in vivo. But animal experiments are time-consuming, high-energy and high cost. Cell culture in vitro is rapid, simple and low cost. And cell models can specifically study the toxic effect of pesticide mixtures to target cells, ruling out the interference of matrix and other systems. So this method is gradually used for evaluation of organophosphorus pesticide mixtures safety in recent years. This paper summarized the effects of organophosphorus pesticide on human health, the interaction patterns and evaluation methods of pesticide mixtures. It also reviewed the applications and research progress of different experimental models in com- bined toxicity induced by organophosphorns pesticides, comparing the advantages and disadvantages of different evaluation methods as well as in vivo and in vitro models. At the same time, it is worth noting that the current evaluations on the combined toxicity effect of organophosphorus pesticide mixtures have some problems, and putting forward the development directions in the future, so as to provide relevant reference about the risk assessment of organophosphorus pesticide residue mixtures in fruits in the future.