宜昌市大气微塑料的分布、呼吸暴露及溯源

Distribution,Respiratory Exposure,and Traceability of Atmospheric Microplastics in Yichang City

微塑料作为一种新兴环境污染物备受关注,但大气微塑料的来源和健康危害尚不明晰.为探究宜昌市不同功能区微塑料的分布特征和人体呼吸暴露风险,分析不同地区大气微塑料的可能来源,于2019年10~12月,采集和分析宜昌市16个观测点的大气微塑料样品,并利用HYSPLIT模型模拟大气后向轨迹.结果表明,宜昌市大气微塑料有纤维状、碎片状和薄膜状这3种形状;透明、红色、黑色、绿色、黄色和紫色这6种颜色;尺寸最小的为10.42μm,最大的为4761.42μm;平均沉降通量为(4400±474)n·(m^(2)·d)^(-1);种类有:聚酯纤维(PET)、丙烯腈-丁二烯-苯乙烯共聚合物(ABS)、聚酰胺(PA)、橡胶(Rubber)、聚乙烯(PE)、醋酸纤维素(CA)和聚丙烯腈(PAN)这7种.各功能区沉降通量依次为:城市居民区>农业生产区>垃圾填埋场>化工园区>城镇居民区.人体呼吸暴露风险评估模型表明,城市居民区成人和儿童每天大气微塑料摄入量(EDI)高于城镇居民区.大气后向轨迹模拟表明,宜昌市各区县大气主要受周边地区影响,部分大气微塑料可能来自周边地区的短距离运输.总的来说,宜昌市大气微塑料沉降通量较大,潜在的生态暴露风险较高,各区县部分微塑料可能经由大气短距离传输而来.该结果可为长江中游地区大气微塑料研究提供基础数据支撑,对大气微塑料污染的溯源和健康风险研究具有重要意义.

As an emerging environmental pollutant,microplastics have attracted much attention,but the sources and health hazards of atmospheric microplastics(AMPs)remain unclear.In order to explore the distribution characteristics,assess the risk of human respiratory exposure,and analyze the sources of AMPs in different functional areas of Yichang City,AMPs samples from 16 observation points were collected and analyzed,and the HYSPLIT model was used.The results showed that the main shapes of AMPs in Yichang City were fiber,fragment,and film,and six colors were observed including transparent,red,black,green,yellow,and purple.The smallest size was 10.42μm,and the largest was 4761.42μm.The deposition flux of AMPs was(4400±474)n·(m^(2)·d)^(-1).The types of APMs were polyester fiber(PET),acrylonitrile-butadiene-styrene copolymer(ABS),polyamide(PA),rubber(Rubber),polyethylene(PE),cellulose acetate(CA),and polyacrylonitrile(PAN).The order of the subsidence flux in each functional area was as follows:urban residential area>agricultural production area>landfill>chemical industrial park>town residential area.The human respiratory exposure risk assessment models showed that the daily intake of AMPs(EDI)for adults and children in urban residential areas was higher than in town residential areas.The atmospheric backward trajectory simulation showed that the AMPs in the districts and counties of Yichang City mainly came from the surrounding areas via short-distance transportation.This study provided basic data support for the research on AMPs in the middle reaches of the Yangtze River and was of great significance for the traceability and health risk research of AMPs pollution.