Risk Assessment Of Quality And Safety On Regional Agricultural Environment And Vegetables

This paper aims to explore the major risk factors affecting both the quality and safety of regional vegetables, by using a systemic and integrated assessment theory. On the basis of Analytic Hierarchy Process (AHP), a tentative risk assessment model was constructed by designing and quantifying the index system which was used for evaluating the quality and safety of regional vegetables. Finally, part of the evaluation indicators were intensively and empirically studied by taking Zhejiang Province as a case.From 2007 to 2010, agro-environmental qualities (irrigation water and soil) and pollutant residues in vegetables were investigated from the vegetable bases of 11 prefecture-level cities in Zhejiang Province. After that, the agro-environmental risks were assessed according to the single pollution index and Nemerow's composite pollution index. Besides, the safety risks of 26 main pollutants in 10 regional vegetables were respectively evaluated by using hazards'risk coefficients (R) and index of food safety (IFS). The results are as follows:1. A risk assessment model for the quality and safety of regional vegetables (in Zhejiang Province) was established. A three-level assessment system for 12 risk indexes was designed and quantified. The assessment system included:1) Agro-environment Risk Indexes (3 indicators)---irrigation water pollution index, soil pollution index, and atmosphere pollution index; 2) Agricultural Inputs Risk Indexes (5 indicators)----seed safety risk coefficient, fertilizer dosage risk coefficient, pesticide dosage risk coefficient, plant growth regulators dosage risk coefficient, and harvest hygiene risk coefficient; 3) Vegetable Products Quality and Safety Risk Indexes (4 indicators)----pesticide residues risk coefficient, heavy metal risk coefficient, vegetable safety index, and proportion of certified vegetables.2. The distribution features of Agro-environment Risk Indexes of Zhejiang Province were analyzed. Empirical studies were conducted in terms of the pollution indexes of irrigation water and soil among the assessment system of Agro-environment Risk Indexes. The results showed that:the irrigation water pollution index in Zhejiang Province from low to high would be Ningbo (0.057) < Taizhou (0.062)< Shaoxing (0.063)< Lishui (0.064)< Zhoushan (0.071)< Wenzhou (0.124)< Quzhou (0.143)< Hangzhou (0.222)< Jinhua (0.223)< Huzhou (0.324)< Jiaxing (0.520); the soil pollution index in Zhejiang Province from low to high would be Zhoushan (0.268)< Huzhou (0.280)< Lishui (0.284) < Jinhua (0.316)< Ningbo (0.317)< Taizhou (0.337)< Shaoxing (0.436)< Wenzhou (0.440)< Hangzhou (0.595)< Quzhou (0.748)< Jiaxing (0.826). On the whole, the agro-environmental risks (considering both irrigation water and soil) in Jiaxing would be the highest, while those in Ningbo, Zhoushan and Taizhou would relatively be the lowest.3. The agro-environmental risks of vegetable bases in various prefecture-level cities in Zhejiang Province were clarified. In all the assessed vegetable bases of different sub-regions, both the single pollution index (pi) and the composite pollution index (Pij) for irrigation water were below 1. Among the total study, the Pij for irrigation water in Jiaxing was 0.520, which was just below the standard pollution index, while the Pij for irrigation water in the other regions were below 0.5 which meant cleanness. Meanwhile, in these assessed vegetable bases, the Pij for oil were all below 1, among which the Pij in Jiaxing and Quzhou were 0.826 and 0.748 respectively, meaning comparative cleanness, and the Pij in the other assessed cities fell into cleanness. However, the pi,for soil Hg in Jiaxing was 1.050 (the only assessed city whose Pi for soil was above 1), meaning slightly pollution by the heavy metal Hg.4. The Vegetable Products Quality and Safety Risk Indexes in Zhejiang Province were detected. The results showed that the pesticide residues risk coefficients in different sub-regions were in the order of Hangzhou (0.105)< Quzhou (0.142)< Jinhua (0.155)< Shaoxing (0.156)< Taizhou (0.186)< Zhoushan (0.199)< Wenzhou (0.211)< Lishui (0.230)< Huzhou (0.242)< Ningbo (0.249)< Jiaxing (0.261); the heavy metal risk coefficients were in the order of Taizhou (0.036)< Ningbo (0.055)< Jiaxing (0.061)< Zhoushan (0.074) < Lishui (0.092)< Shaoxing (0.094)< Hangzhou (0.105)< Huzhou (0.107)< Jinhua (0.110)< Wenzhou (0.155)< Quzhou (0.192); and the vegetable safety index (IFS) were Hangzhou (0.007)=Lishui (0.007)=Shaoxing (0.007)< Jinhua (0.009)< Wenzhou (0.010)< Zhoushan (0.014)=Huzhou (0.014)< Taizhou (0.022)< Ningbo (0.024)< Quzhou (0.035)< Jiaxing (0.040).5. The quality and safety, as well as the existing pollutants risks of different vegetables across the entire province were analysed. Among the assessed 1,760 vegetables samples, the IFS was 0.017, showing a good status of their quality and safety. The most 10 safest vegetables would be:cucumber> cabbage > towel gourd> tomato> water bamboo> celery> leek> Chinese cabbage> eggplant> cowpea. Seventeen kinds of pollutants were detected and their pollution risk rates were cadmium> lead> mercury> cypermethrin> chlorpyrifos> cyhalothrin> triazophos> acephate> acephatemet> folimat= fenvalerate> fenpropathrin> malathion> parathion=dichlorvos> dipterex= deltamethrin; The pollutants with high risks would be:chlorpyrifos, cadmium, cypermethrin, lead, triazophos and acephatemet, while the pollutants with medium risks would be:cyhalothrin, folimat, fenvalerate, and the remaining pollutants showed low risks. Additionally, the pollutant indexes with limited acceptance would be:cadmium and triazophos, while the other indexes would have no side effect on vegetable safety.