| Microplastic,an emerging pollutant,has got widespread attention at international level.Some scholars that study microplastics in China mainly focused specific sectors,such as microplastic pollution investigation,toxicology,mechanism of microplastics production and so on.These subjects were of significant significance in clarifying the degree of environment damages caused by microplastics.In terms of microplastic prevention,the crux of cutting down microplastics is to formulate and implement management countermeasures at source,but the studies concerning this field is lacking to date.This study focused on the source management,to study the feasible options aiming at stopping the deterioration of microplastic pollution,to establish the system structure concerning microplastic prevention through the methods of surveying associated references,empirical analysis and so on.The specific works and conclusions were shown as below.（1）The basic information concerning microplastic were investigated in seven small-sized estuaries in Shanghai,the results showed that the range of microplastics abundance were13.53±4.6 to 44.93±9.41 particles L-1,with the mean abundance of 26.076±12.15 particles L-1,microplastic abundances in present study were higher than some previous domestic investigations about surface water microplastics.The study also found the correlation between surface water quality and microplastic abundance,namely the worse the water quality,the higher microplastic abundance.The range of microplastic diameter were 0.02-2.535 mm,the proportion of microplastics with particle sizes less than 2mm was reach up to 99.5%.Polyethylene and polypropylene were the dominant types in all detected microplastics,the proportion were 50%and 37.5%,respectively.Some main origins of microplastic in this study included plastic agricultural film,plastic packaging,fishery industry and so on.（2）The methods of questionnaire surveys and mathematical modeling were used to investigate the citizen participation in plastic bags reduction.The order of five potential variables influencing“behavioral intention”was shown as below:Consequence of awareness（0.894）>Moral norm（0.789）>Subjective norm（0.528）>Perceived behavioral control（0.256）>Attitude（-0.035）.In addition,the analysis shows that"perceived behavior control"plays a completely mediating role in"subjective norms"and"behavioral intentions".Finally,the policy proposals benefited to the enhancement of public involvement were put forward.（3）From the perspective of the whole process of“collection–transport-rubbish transfer station-incineration/landfill”,the total social cost loss caused by dry garbage is￥1154.06 per ton.Taking[16 pcs/（person per month）]as the monthly plastic bag consumption of residents in Shanghai,it is estimated that the plastic bags waste generated annually in Shanghai was 8.29tons,accounting for 1.7%of the residual waste.The selling price of a single plastic bag was estimated based on three aspects,including social cost,production cost,and public acceptance price.The social cost of a single plastic bag is￥0.021 in Shanghai,the production cost is￥0.36,and the price range that interviewee could accept was“￥0.5-1”.Finally,the range of“￥0.5-1”was preliminarily selected as the selling price of a single plastic bag,the specific value was affected by some factors,including costs resulting from the implementation of the plastic bag taxation policy,the cost difference of residual waste caused by plastic bags,the environment cost of microplastic that derived from broken plastic bag and so on.（4）Based on the whole process of“raw materials-production-distribution-dumping-recycling（treatment）”of plastic products,to analyze the reduction policies and practices involved in the derivation of microplastics in China,to draw on mature and effective management experience abroad,to combine with sampling analysis,questionnaire analysis and economic measures analysis.Finally,the proposals related to the establishment of microplastics reduction system were offered. |
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