Department of Civil Engineering, Indian Institute of Technology Delhi, Delhi, India.
Department of Civil Engineering, Indian Institute of Technology Kanpur, Kanpur, India.
Environ Sci Pollut Res Int. 2018 Mar;25(9):8747-8764. doi: 10.1007/s11356-017-1174-9. Epub 2018 Jan 11.
This study presents the concentration of submicron aerosol (PM) collected during November, 2009 to March, 2010 at two road sites near the Indian Institute of Technology Delhi campus. In winter, PM composed 83% of PM indicating the dominance of combustion activity-generated particles. Principal component analysis (PCA) proved secondary aerosol formation as a dominant process in enhancing aerosol concentration at a receptor site along with biomass burning, vehicle exhaust, road dust, engine and tire tear wear, and secondary ammonia. The non-carcinogenic and excess cancer risk for adults and children were estimated for trace element data set available for road site and at elevated site from another parallel work. The decrease in average hazard quotient (HQ) for children and adults was estimated in following order: Mn > Cr > Ni > Pb > Zn > Cu both at road and elevated site. For children, the mean HQs were observed in safe level for Cu, Ni, Zn, and Pb; however, values exceeded safe limit for Cr and Mn at road site. The average highest hazard index values for children and adults were estimated as 22 and 10, respectively, for road site and 7 and 3 for elevated site. The road site average excess cancer risk (ECR) risk of Cr and Ni was close to tolerable limit (10) for adults and it was 13-16 times higher than the safe limit (10) for children. The ECR of Ni for adults and children was 102 and 14 times higher at road site compared to elevated site. Overall, the observed ECR values far exceed the acceptable level.
本研究展示了 2009 年 11 月至 2010 年 3 月期间在印度理工学院德里校区附近两个道路站点采集的亚微米气溶胶（PM）浓度。在冬季，PM 占 PM 的 83%，表明燃烧活动生成的颗粒占主导地位。主成分分析（PCA）证明二次气溶胶的形成是增强受体站点气溶胶浓度的主要过程，同时还有生物质燃烧、车辆尾气、道路灰尘、发动机和轮胎磨损以及二次氨。根据另一项平行研究提供的道路站点和高空站点的痕量元素数据集，对成年人和儿童的非致癌和超额癌症风险进行了估计。在道路和高空站点，Mn > Cr > Ni > Pb > Zn > Cu 的平均危害商（HQ）呈下降趋势。对于儿童，Cu、Ni、Zn 和 Pb 的 HQ 平均值处于安全水平；然而，Cr 和 Mn 的 HQ 值在道路站点超过了安全限制。道路站点的儿童和成年人的平均最高危害指数值分别估计为 22 和 10，高空站点分别为 7 和 3。道路站点的成年人和儿童 Cr 和 Ni 的平均超额癌症风险（ECR）接近可接受限值（10），而对于儿童，其 ECR 是安全限值（10）的 13-16 倍。与高空站点相比，道路站点的成年人和儿童的 Ni 的 ECR 分别高出 102 倍和 14 倍。总的来说，观察到的 ECR 值远远超过了可接受的水平。
