Department of Civil Engineering, SRM Research Institute, SRM Institute of Science and Technology, Kattankulathur, 603203, Tamil Nadu, India.
Department of Chemistry, Dr.B.R.Ambedkar University, Agra, Khandari Campus, 282002, India.
Chemosphere. 2021 Jan;263:127700. doi: 10.1016/j.chemosphere.2020.127700. Epub 2020 Aug 1.
Recent studies from India reported polychlorinated biphenyls (PCBs) associated with incomplete combustion processes. In this study we have monitored atmospheric PCBs in Agra, a non-metropolitan city of northern India. During first month of summer and winter of 2017, polyurethane foam based passive air sampler (PUF-PAS) was deployed at each of 14 locations across urban, suburban and rural transects and one background site. Range of ΣPCBs varied between 25 and 1433 pg/m (Avg ± Stdev: 460 ± 461) in summer and 26-205 pg/m (Avg ± Stdev: 106 ± 59) in winter. Mean ΣPCBs concentration, showed an urban > suburban > rural trend in summer while, in winter a rural > urban > suburban trend was observed. PCB-52 was the dominant congener and after excluding this congener no significant difference was observed between summer and winter PCB concentrations. Using a combination of K-means cluster and principal component analysis (PCA) four major source types were identified. Open burning source accorded 80% of atmospheric PCBs, majorly indicator PCBs while the remaining 20% was contributed by atmospheric transport, petrogenic combustion and biomass burning. From the ten days back trajectory of the air mass it can be suggested that atmospheric transport from the hotspots resulted in a minor percentage of dioxin like PCBs in Agra. Maximum TEQs was accorded by PCB-77 (30%) and it is consistent with previous observations from Agra. Levels observed in the current study are well within the public health guideline based on inhalation unit risk (10 ng/m) and United States Environmental Protection Agency's regional screening level high risk tier (4.9 ng/m) for ambient air.
最近来自印度的研究报告称，多氯联苯（PCBs）与不完全燃烧过程有关。在这项研究中，我们监测了印度北部非大都市城市阿格拉的大气 PCBs。在 2017 年夏季和冬季的第一个月，在城市、郊区和农村的 14 个地点以及一个背景地点，每个地点都部署了基于聚氨酯泡沫的被动空气采样器（PUF-PAS）。夏季 ΣPCBs 的范围在 25 到 1433 pg/m 之间（平均值 ± 标准差：460 ± 461），冬季在 26 到 205 pg/m 之间（平均值 ± 标准差：106 ± 59）。夏季平均 ΣPCBs 浓度表现出城市 > 郊区 > 农村的趋势，而冬季则观察到农村 > 城市 > 郊区的趋势。PCB-52 是主要的同系物，排除这种同系物后，夏季和冬季 PCB 浓度之间没有观察到显著差异。使用 K-均值聚类和主成分分析（PCA）相结合的方法，确定了四种主要的源类型。露天燃烧源占大气 PCBs 的 80%，主要是指示性 PCBs，其余 20%来自大气传输、石油燃烧和生物质燃烧。从空气团的十天回溯轨迹可以看出，大气从热点的传输导致阿格拉大气中二恶英样 PCBs 的比例较小。PCB-77（30%）赋予最大的 TEQs，这与阿格拉之前的观察结果一致。本研究中观察到的水平远低于基于吸入单位风险（10ng/m）的公共卫生指南和美国环境保护局的区域筛选水平高风险层（4.9ng/m）。
