Sonwani Saurabh, Saxena Pallavi, Khillare P S
School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India.
Department of Environmental Studies, Zakir Husain Delhi College, University of Delhi, New Delhi, India.
Inhal Toxicol. 2022;34(1-2):39-50. doi: 10.1080/08958378.2022.2030442. Epub 2022 Feb 3.
This study focuses on the profile of ambient particulate polycyclic aromatic hydrocarbons (PAHs), their seasonal distribution, source identification and human health risk assessment due to inhalation exposure of ambient PAHs in Delhi, India. Two sampling sites were chosen, one at roadway (MH) and other at urban background (JNU) site in Delhi. Determination of PAHs was carried with the help of HPLC with UV detector. Principal component analysis and Molecular diagnostic ratios were used for the source apportionment of PAHs. Health risks associated with inhalation of particulate PAHs were assessed using benzo(a)pyrene equivalent concentration and incremental lifetime cancer risk (ILCR) approach. The results showed that the average mass concentration of Σ PAHs near roadway (67.8 ± 40.2 ng m) is significantly higher than urban background site (56 ± 30 ng m). Moreover, source apportionment study indicated that major PAH-emission sources in Delhi NCR are traffic and coal combustion. ILCR values at both the sites fall in the range of 10-10 that corresponds to the priority risk level (10) and higher than the acceptable risk level (10). The high PAHs concentration at MH site was due to it's nearness to busy traffic area. Thus, the spatial variations in PAHs were influenced by local emission sources. The high PAHs level during the winter season can be due to their higher emissions from local heating sources, shift of gas/particle partitioning toward the particulate phase at low temperature and reduced photochemical degradation of some PAHs in winter. The low level of PAHs in monsoon season can be attributed to their wet scavenging and higher percentage in vapor phase. PCA showed that the emissions from vehicles predominate at MH site; whereas, coal combustion and traffic both are the significant PAHs sources at JNU site. Health risk assessment revealed that the highest exposure risks occur at busy traffic site, thereby indicating a significantly higher health risk to the population of Delhi.
本研究聚焦于印度德里环境空气中颗粒态多环芳烃（PAHs）的特征、其季节分布、来源识别以及因吸入环境PAHs而导致的人体健康风险评估。选取了两个采样点，一个位于德里的道路旁（MH），另一个位于城市背景区域（JNU）。借助配备紫外检测器的高效液相色谱法对PAHs进行测定。采用主成分分析和分子诊断比值法对PAHs进行源解析。利用苯并(a)芘当量浓度和终生癌症风险增量（ILCR）方法评估吸入颗粒态PAHs相关的健康风险。结果表明，道路旁附近ΣPAHs的平均质量浓度（67.8±40.2 ng/m）显著高于城市背景点（56±30 ng/m）。此外，源解析研究表明，德里国家首都辖区主要的PAH排放源是交通和煤炭燃烧。两个采样点的ILCR值均落在10-10范围内，这对应于优先风险水平（10）且高于可接受风险水平（10）。MH采样点PAHs浓度较高是由于其靠近繁忙交通区域。因此，PAHs的空间变化受当地排放源影响。冬季PAHs水平较高可能是由于当地供暖源排放增加、低温下气/粒分配向颗粒相转移以及冬季部分PAHs光化学降解减少。季风季节PAHs水平较低可归因于其被雨水冲刷以及在气相中的占比更高。主成分分析表明，车辆排放物在MH采样点占主导；而在JNU采样点，煤炭燃烧和交通都是重要的PAHs来源。健康风险评估显示，最高暴露风险出现在繁忙交通站点，从而表明德里人群面临的健康风险显著更高。
