Research On The Level Of Pesticide Residues In Marketed Fruits And Vegetables Of China And Its Influening Local Factors

Pesticide residues in food have caused many negative impacts on human health,but the current agricultural production still requires the use of pesticides.As one of the most commonly consumed foods,fruits and vegetables have received more and more attention to their pesticide residues.Therefore,evaluating the pesticide residue levels in commercially available fruits and vegetables,and identifying the influencing local factors,are of great significance to maintain public health and diet safety,and create a good social atmosphere for food consumption.At present,there are two main methods for evaluating pesticide residue levels in domestic studies.One is to use the Index of Food Safety(IFS)to evaluate the health risks of pesticide residues,and the other is to use a single indicator to determine whether the pesticide residues are compliant.There is a lack of comprehensive evaluation of pesticide residue levels by using multiple indicators,as well as the analysis on the influencing factors of pesticide residue level differences between cities.This thesis aims to analyze the pesticide residues level of marketed fruits and vegetabels across Chinese cities and their influencing local factors by building a comprehensive evaluation system.The thesis also compares the differences in pesticide residues at home and abroad to propose suggestions to improve Chinese food safety.Based on the detection data of pesticide residues on marketed fruits and vegetables in 42 cities in mainland China from 2013 to 2014,the thesis builds an evaluation system consisting of 5 indicators including compliance rate,undetected rate,detection rate of highly toxic pesticide samples,proportion of banned pesticide detection frequency,and the average number of pesticides detected in a single sample.The entropy weight method is used to calculate the pesticide residue index(PRI)to indicate the pesticide residue level in urban marketed fruits and vegetables.The higher the PRI value,the lower the pesticide residue level.The lower the PRI value,the higher the level of residues.Nine indicators were selected from the three aspects of economy,agriculture and government supervision.Analyzing the correlation between these indicators and PRI,and identifying the main influencing factors of pesticide residue of marketed fruits and vegetables by ordinal Logistic regression model.The thesis also compares the differences in pesticide residues on marketed fruits and vegetables between China,the USA,and the EU,and takes suggestions to improve pesticide residues in Chinese food.The results show that:(1)There are inter-city differences in pesticide residue levels of marketed fruits and vegetables across China,and the regional differences of PRI are obvious.The urban PRI values range from 0.213 to 0.854,with an average of0.54.The average PRI of cities in the Western China is 0.624,which means this region has a lower pesticide residues level.The average PRI of cities in the Eastern China is 0.501,which means this region has a higher pesticide residues level.The average values of urban PRI in the Northeast and the Central China are 0.527 and0.56,which means these two regions have the pesticide residues levels close to the national average.(2)PRI is affected by the local economy,agriculture and government supervision.Per capita GDP,the proportion of tertiary industry to GDP and foreign direct investment among economic factors,and provincial pesticide output,provincial cultivated area,and city’s pesticide usage per unit of cultivated area among agricultural factors,and number of provincial pesticide-related policies and the transparency of supervision of food safety among government supervision factors are significantly related to the pesticide residue levels of marketed fruits and vegetables across cities.Among them,per capita GDP,city’s pesticide usage per unit of cultivated area and the transparency of supervision of food safety are the main factors affecting pesticide residues level of marketed fruits and vegetables.The results of ordinal Logistic regression analysis show that:(1)For every 10,000 yuan increase in per capita GDP,the pesticide residue level decreased by 38.4%;(2)For every 1 ton /thousand hectares of pesticide use per unit of cultivated area in the city,the pesticide residue level increased by 16%;(3)The lower the transparency of supervision of food safety,the higher the level of pesticide residues.(3)Compared with USA and the EU,China has the highest pesticide residue compliance rate and the lowest violation rate,but the different MRL standards of them will affect the comparison of pesticide residue levels based on indicators.China has higher detection rate compared with USA and the EU,which means pesticide residues in marketed fruits and vegetables in China are more common.The top 5 pesticides detected in foods in China,USA,and the EU are all low-or medium-toxic pesticides.And high-toxic pesticide residues have been detected in this three countries or regions.This study provides a preliminary mathematical basis and scientific basis for promoting the improvement of food safety in the country,and has great significance to understand the quality and safety status of marketed fruits and vegetables,maintain public health and diet safety,and create a good social atmosphere for safe consumption.