沧州市郊采暖期大气颗粒物中重金属的粒径分布及健康风险评价

Size distribution and health risk assessment of heavy metals in atmospheric particulate matter during heating period in the suburb of Cangzhou

为了解沧州市郊采暖期大气颗粒物中重金属粒径分布和健康风险,于2018年11—12月使用分级撞击式采样器采集大气颗粒物样品(粒径符合总悬浮颗粒物(TSP)标准),采用电感耦合等离子体发射光谱(ICP-OES)测定Fe、Cu、Mn、Pb和Zn含量,利用富集因子法和美国环境保护署推荐的健康风险评价模型,分析重金属主要来源并对其经呼吸途径的人体健康风险进行评价。结果表明,Fe、Cu、Mn主要分布在粗粒子中,Zn和Pb主要分布在细粒子中。Fe为粗粒子单峰型,Cu和Mn为粗粒子峰值大于细粒子峰值双峰型,Pb和Zn为细粒子峰值大于粗粒子峰值双峰型。细粒子中Mn、Cu、Zn和Pb富集因子高于粗粒子,且Pb和Zn在细粒子中富集因子均高于100,发生高度富集;Zn、Pb、Mn和Cu富集因子峰值位于>0.43~1.10μm。TSP和PM 9.0中Mn对成人和儿童均存在非致癌风险,PM 2.1中Mn对成人和儿童的非致癌风险可以忽略;Pb对成人和儿童的致癌风险均可以忽略;Mn和Pb健康风险峰值均位于>1.10~2.10μm,健康风险评价时应考虑粒径对人群健康风险的影响。

In order to understand the size distributions and health risks of heavy metals in atmospheric particulate matter with different particle sizes during heating period in the suburb of Cangzhou,the atmospheric particulate matter samples(belong to TSP)with different particle sizes were collected by using impact sampler from November to December in 2018.The contents of Fe,Cu,Mn,Pb and Zn were determined by ICP-OES.The main sources of heavy metals were analyzed by enrichment factor method and the health risks of heavy metals through respiratory pathway were assessed by the USEPA health risk assessment model.The results showed that Fe,Cu and Mn were mainly distributed in coarse particles,while Zn and Pb were mainly distributed in fine particles.Fe exhibited unimodal distributions in the coarse particles.Cu and Mn exhibited bimodal distributions with the major peaks in the coarse particles and the minor peaks in fine particles.Pb and Zn exhibited bimodal distributions with the major peaks in the fine particles and the minor peaks in coarse particles.The enrichment factors of Mn,Cu,Zn and Pb in fine particles were higher than those in coarse particles.Especially,the enrichment factors of Pb and Zn in fine particles were higher than 100,resulting in high enrichment.The peak values of enrichment factors of Zn,Pb,Mn and Cu were at>0.43-1.10μm.Mn in TSP and PM_(9.0) had non-carcinogenic risks for both adults and children,while Mn in PM_(2.1) had negligible non-carcinogenic risks for both adults and children.Pb had no carcinogenic risks for both adults and children.The health risks of Mn and Pb exhibited peaks at>1.10-2.10μm,and the impact of particle size on the health risks should be considered in the health risk assessment.