上海某生活垃圾焚烧炉周边大气中二噁英类化合物监测以及人群呼吸暴露量评估

Monitoring of atmospheric PCDD/Fs and evaluation of human inhalation exposure levels in the vicinity of a municipal solid waste incinerator in Shanghai

[背景]焚烧发电是目前城市生活垃圾处理的一种主要方式,同时也会产生二噁英污染,其可直接进入呼吸系统,影响人体健康。[目的]利用被动采样技术获取上海某生活垃圾焚烧炉周边大气环境中二噁英类化合物(polychlorinated dibenzo-p-dioxins/furans,PCDD/Fs)的浓度、污染特征以及季节变化,并且评估周边人群的二噁英类化合物呼吸暴露量。[方法]选取上海地区某生活垃圾焚烧炉主导风向下风向距离圾焚烧炉950 m(西北向,采样点A)和700 m(东南向,采样点B)左右两个点位,利用被动采样技术在2017年逐月采集并分析环境大气中17种2,3,7,8位被氯取代的PCDD/Fs的含量,比较不同季节污染特征,并分析同系物的组成特征。利用主成分分析对生活垃圾焚烧炉周边环境大气中PCDD/Fs进行溯源分析。根据分析所得环境大气含量数据计算生活垃圾焚烧炉周边人群PCDD/Fs呼吸暴露量。[结果]上海地区某生活垃圾焚烧炉周边大气中PCDD/Fs的浓度平均值(范围)为1.23(0.378~2.49)pg/m3(采样点A)和1.37(0.487~3.36)pg/m3(采样点B);对应的毒性当量(TEQ)平均值(范围)为113(30.9~195)fg WHO-TEQ/m3(采样点A)和119(43.2~409)fg WHO-TEQ/m3(采样点B)。溯源结果表明研究区域环境大气中PCDD/Fs的主要来源为垃圾焚烧和交通污染。该生活垃圾焚烧厂周边成人的PCDD/Fs呼吸暴露量为9.16~39.1 fg WHO-TEQ/(kg·d);儿童的PCDD/Fs呼吸暴露量为18.5~79.0 fg WHO-TEQ/(kg·d)。[结论]上海某生活焚烧炉周边大气样品(被动采样)中PCDD/Fs的含量略高于上海城市背景(被动采样)中PCDD/Fs的含量。研究区域大气中PCDD/Fs可能主要来源于垃圾焚烧源和交通污染源。该焚烧厂周边成人和儿童的PCDD/Fs呼吸暴露量均低于人体每日可耐受摄入量的10%。

[Background] Waste incineration power generation is a main municipal waste disposal method, but it also releases dioxins into the air, which can directly enter respiratory system and produce adverse health effects. [Objective] Passive sampling technique is used to obtain the concentration, pollution characteristics, and seasonal changes of polychlorinated dibenzo-p-dioxins/furans(PCDD/Fs) in the atmosphere around a municipal solid waste incinerator(MSWI) in Shanghai, and to assess the exposure levels of PCDD/Fs in surrounding population.[Methods] The atmospheric samples were collected every month in 2017 using passive sampling technique from two sampling sites, 950 m(northwest, site A) and 700 m(southeast, site B)downwind of the MSWI in Shanghai. Seventeen kinds of 2, 3, 7, 8 substituted PCDD/Fs in the atmosphere were analyzed to compare the seasonal variation and composition characteristics of the homologues. Principal component analysis was applied for source identification of PCDD/fs in the ambient atmosphere around the MWSI. According to the atmospheric concentration data, the PCDD/Fs inhalation exposure levels of the surrounding population were calculated. [Results] The mean concentrations(ranges) of PCDD/Fs in the atmosphere around the MSWI in Shanghai were 1.23(0.378-2.49) pg/m3(Site A) and 1.37(0.487-3.36) pg/m3(Site B), respectively;the toxic equivalent quantity(TEQ) concentration ranges(means) were 30.9-195(113) fg WHO-TEQ/m3(Site A) and 43.2-409(119) fg WHO-TEQ/m3(Site B), respectively. The results of source identification showed that the main sources of PCDD/Fs in the atmosphere of the study area were waste incineration and traffic pollution. The PCDD/Fs inhalation exposure level for surrounding adults was in the range of 9.16-39.1 fg WHO-TEQ/(kg·d), and the level for surrounding children was in the range of 18.5-79.0 fg WHO-TEQ/(kg·d).[Conclusion] The concentration of PCDD/Fs in atmosphere(passive sampling) around the MSWI in Shanghai is slightly higher than that(passive sampling) in the background area of Shanghai. PCDD/Fs in the atmosphere of the study area are probably released from waste incineration and traffic pollution. The PCDD/Fs inhalation exposure levels for surrounding adults and children are all below 10% of the acceptable daily intake amount.