School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China.
Environ Sci Technol. 2013 Jul 16;47(14):7615-23. doi: 10.1021/es400338h. Epub 2013 Jun 27.
Chlorinated polycyclic aromatic hydrocarbons (ClPAHs) have been reported to be formed during incineration processes. Despite dioxin-like toxicities of ClPAHs, little is known on the occurrence of these chemicals in the environment. In this study, concentrations of 24-h airborne PM10 and PM2.5-associated ClPAHs and their corresponding parent PAHs were monitored from October 2011 to March 2012 in a suburban area in Shanghai, China. In addition, daytime and nighttime particle samples were collected for 7 days in April from the same sampling site. Twelve of twenty ClPAH congeners were found in PM10 and PM2.5 at concentrations ranging from 2.45 to 47.7 pg/m(3) with an average value of 12.3 pg/m(3) for PM10, and from 1.34 to 22.3 pg/m(3) with an average value of 9.06 pg/m(3) for PM2.5. Our results indicate that ClPAHs are ubiquitous in inhalable fine particles. The concentrations of ∑ClPAHs and specific congeners such as 9-ClPhe, 3-ClFlu, 1-ClPyr, 7-ClBaA, and 6-ClBaP in particles collected during nighttime were higher than those collected during daytime, which suggests not only diffusion of ClPAHs in air by atmospheric mixing but also photochemical degradation during daylight hours. Among the individual ClPAHs determined, 6-ClBaP, 1-ClPyr, and 9-ClPhe were the dominant compounds in PM10 and PM2.5. The percent composition of 6-ClBaP, 1-ClPyr, 7-ClBaA, and 3-ClFlu between PM10 and PM2.5 was similar. Significant positive correlations were found between concentrations of ClPAHs and their corresponding parent PAHs, particle mass, and total organic carbon (organic carbon plus elemental carbon), indicating that ClPAHs are sorbed onto carbonaceous matter of PM. Concentrations of parent PAHs predicted by multiple linear regression models with PM mass, total organic carbon, temperature, and relative humidity as variables reflected the measured concentrations with a strong coefficient of determination of 0.917 and 0.946 for PM10 and PM2.5, respectively. However, the models generated to predict ClPAH concentrations in PM did not yield satisfactory results, which suggested the differences in physical-chemical properties and formation processes between ClPAHs and their corresponding parent PAHs. 7-ClBaA and 6-ClBaP collectively accounted for the preponderance of the total dioxin-like TEQ concentrations of ClPAHs (TEQClPAH) in PM samples. Exposure to toxic compounds such as ClPAHs and PAHs present in PM2.5 can be related to adverse health outcomes in people.
氯化多环芳烃（ClPAHs）已被报道在焚烧过程中形成。尽管 ClPAHs 具有类似二恶英的毒性，但对于这些化学物质在环境中的存在情况知之甚少。本研究于 2011 年 10 月至 2012 年 3 月在上海市郊区监测了 24 小时空气 PM10 和 PM2.5 相关 ClPAHs 及其相应母体多环芳烃（PAHs）的浓度。此外，在同一采样点于 2012 年 4 月的 7 天内采集了白天和夜间的颗粒物样本。在 PM10 和 PM2.5 中发现了 24 种 ClPAH 同系物，浓度范围为 2.45 至 47.7 pg/m3，PM10 的平均值为 12.3 pg/m3，1.34 至 22.3 pg/m3，PM2.5 的平均值为 9.06 pg/m3。我们的研究结果表明，ClPAHs 普遍存在于可吸入的细颗粒物中。夜间采集的颗粒中∑ClPAHs 和特定同系物（如 9-ClPhe、3-ClFlu、1-ClPyr、7-ClBaA 和 6-ClBaP）的浓度高于白天采集的浓度，这不仅表明 ClPAHs 通过大气混合在空气中扩散，而且表明在白天光照条件下会发生光化学降解。在所测定的个别 ClPAHs 中，6-ClBaP、1-ClPyr 和 9-ClPhe 是 PM10 和 PM2.5 中的主要化合物。6-ClBaP、1-ClPyr、7-ClBaA 和 3-ClFlu 在 PM10 和 PM2.5 中的百分比组成相似。ClPAHs 及其相应母体 PAHs、颗粒物质量和总有机碳（有机碳加元素碳）之间存在显著的正相关关系，表明 ClPAHs 被吸附到 PM 的碳质物质上。以颗粒物质量、总有机碳、温度和相对湿度为变量的多元线性回归模型预测的母体 PAHs 浓度与实测浓度的相关系数分别为 0.917 和 0.946，反映了这一结果，表明 ClPAHs 和其相应母体 PAHs 在物理化学性质和形成过程上存在差异。在 PM 中生成的预测 ClPAH 浓度的模型没有产生令人满意的结果。PM 样品中 ClPAHs 的总二恶英类似毒性当量浓度（TEQClPAH）主要由 7-ClBaA 和 6-ClBaP 组成。暴露于 PM2.5 中存在的类似二恶英的有毒化合物（如 ClPAHs 和 PAHs）可能会对人体健康产生不良影响。
