School of Environmental Science and Engineering, Shandong University, Qingdao, 266237, China.
Department of Chemistry, State University of New York College of Environmental Science and Forestry, Syracuse, NY, 13210, USA.
Environ Res. 2023 Jan 1;216(Pt 1):114139. doi: 10.1016/j.envres.2022.114139. Epub 2022 Sep 6.
Hexachlorobutadiene (HCBD) was listed as a new persistent organic pollutant for global regulation under Stockholm Convention in 2015, and there has been scarce information on its atmospheric concentrations, distributions, and emission sources. HCBD air samples were collected and analyzed to characterize concentrations and distributions at high elevation and urban sites as well as emission source locations in Northern China. We found ambient concentrations of HCBD in Northern China averaged at 34 ± 16 and 36 ± 28 pptv at urban sites in Jinan and Tai'an, respectively, and 31 ± 21 pptv at a high-elevation site Mount Tai. HCBD concentrations at the high elevation and urban sites were found to be affected by long-range transport under the influence of the East Asian monsoon climate. Over potential sources areas, we found concentrations of 76 ± 33 pptv in a mixed factory park, 59 ± 21 pptv in a rubber plant and 74 ± 8 pptv in a municipal solid waste (MSW) landfill area, which were all several times higher than in urban sites. The large concentration gradient across the various environments revealed strong emission sources of HCBD, especially over MSW landfill and Cl-compound production and application areas. An emission rate of 9.2 × 10 kg/yr and an oxidation rate of 32.9 kg/yr for HCBD were estimated for the mixed factory park. OH and Cl are much more active in reaction with HCBD than other oxidants in the atmosphere. Dry deposition and oxidation removed about 5.3% and 0.04%, respectively, of the emitted, suggesting that ∼95% of the emitted HCBD remaining in the atmosphere and could be transported for redistribution. Our findings revealed significant emission sources of HCBD in northern China, which was in turn affected by major sources in East-central China. The regional influence of HCBD pollution warrants serious concerns and points to the need to develop mitigation strategies.
六氯丁二烯 (HCBD) 于 2015 年被《斯德哥尔摩公约》列为全球监管的新型持久性有机污染物，但有关其大气浓度、分布和排放源的信息却很少。本研究采集并分析了 HCBD 空气样本，以描述中国北方高海拔和城市地区以及排放源地点的浓度和分布。我们发现，中国北方空气中 HCBD 的环境浓度在济南和泰安的城市地区分别平均为 34±16 和 36±28 pptv，在泰山的高海拔地区为 31±21 pptv。在高海拔和城市地区，HCBD 浓度受到东亚季风气候影响下的长距离传输的影响。在潜在的污染源地区，我们发现混合工厂园区的浓度为 76±33 pptv，橡胶厂为 59±21 pptv，城市垃圾填埋场为 74±8 pptv，均高于城市地区的浓度数倍。在各种环境中存在的大浓度梯度表明 HCBD 排放源很强，特别是在城市垃圾填埋场和 Cl 化合物生产和应用区。混合工厂园区的 HCBD 排放速率为 9.2×10kg/yr，氧化速率为 32.9kg/yr。OH 和 Cl 在与 HCBD 的反应中比大气中的其他氧化剂更为活跃。干沉降和氧化分别去除了约 5.3%和 0.04%的排放物，表明约 95%的排放 HCBD 仍留在大气中并可能被输送重新分配。我们的研究结果表明，中国北方存在显著的 HCBD 排放源，而这些排放源又受到中国中东部主要污染源的影响。HCBD 污染的区域性影响值得严重关注，并表明需要制定缓解策略。
