Abstract：
This study investigated the concentrations, seasonal variations, sources, and human health risks associated with exposure to heavy elements (As, Al, Pb, Cr, Mn, Cu, Zn, and Ni) of PM2.5 at an urban location of Delhi (28° 38\' N, 77° 10\' E; 218 m amsl), India, from January 2013 to December 2021. The average mass concentration of PM2.5 throughout the study period was estimated as 127 ± 77 µg m-3, which is exceeding the National Ambient Air Quality Standards (NAAQS) limit (annual: 40 µg m-3; 24 h: 60 µg m-3). The seasonal mass concentrations of PM2.5 exhibited at the order of post-monsoon (192 ± 110 µgm-3) > winter (158 ± 70 µgm-3) > summer (92 ± 44 µgm-3) and > monsoon (67 ± 32 µgm-3). The heavy elements, Al (1.19 µg m-3), Zn (0.49 µg m-3), Pb (0.43 µg m-3), Cr (0.21 µg m-3), Cu (0.21 µg m-3), Mn (0.07 µg m-3), and Ni (0.14 µg m-3) exhibited varying concentrations in PM2.5, with the highest levels observed in the post-monsoon season, followed by winter, summer, and monsoon seasons. Six primary sources throughout the study period, contributing to PM2.5 were identified by positive matrix factorization (PMF), such as dust (paved/crustal/soil dust: 29.9%), vehicular emissions (17.2%), biomass burning (15.4%), combustion (14%), industrial emissions (14.2%), and Br-rich sources (9.2%). Health risk assessments, including hazard quotient (HQ), hazard index (HI), and carcinogenic risk (CR), were computed based on heavy elements concentrations in PM2.5. Elevated HQ values for Cr and Mn linked with adverse health impacts in both adults and children. High carcinogenic risk values were observed for Cr in both adults and children during the winter and post-monsoon seasons, as well as in adults during the summer and monsoon seasons. The combined HI value exceeding one suggests appreciable non-carcinogenic risks associated with the examined elements. The findings of this study provide valuable insights into the behaviour and risk mitigation of heavy elements in PM2.5, contributing to the understanding of air quality and public health in the urban environment of Delhi.
摘要：
这项研究调查了浓度，季节性变化,来源,以及与接触重元素相关的人类健康风险(As，Al,Pb,Cr,Mn,Cu,Zn,和Ni）在德里市区（28°38N，东经77°10；218米amsl)，印度,从2013年1月到2021年12月。整个研究期间PM2.5的平均质量浓度估计为127±77µgm-3，超过了国家环境空气质量标准（NAAQS）的限值（每年：40µgm-3；24小时：60µgm-3）。PM2.5的季节性质量浓度表现为季风后（192±110µgm-3）>冬季（158±70µgm-3）>夏季（92±44µgm-3）和>季风（67±32µgm-3）。重元素,铝（1.19µgm-3），锌（0.49µgm-3），铅(0.43µgm-3)，Cr（0.21µgm-3），铜（0.21µgm-3），锰(0.07µgm-3)，和Ni（0.14µgm-3）在PM2.5中表现出不同的浓度，在季风后季节观察到最高水平，接着是冬天,夏天,季风季节。整个研究期间的六个主要来源，对PM2.5的贡献是通过正矩阵分解(PMF)确定的，如灰尘(铺面/地壳/土壤灰尘:29.9%)，车辆排放(17.2%)，生物质燃烧(15.4%)，燃烧（14%），工业排放量（14.2%），和富含溴的来源(9.2%)。健康风险评估,包括危险商(HQ)，危害指数(HI)，和致癌风险（CR），根据PM2.5中的重元素浓度计算。Cr和Mn的HQ值升高与成人和儿童的不利健康影响有关。在冬季和季风后季节，成人和儿童的Cr均具有较高的致癌风险值。以及夏季和季风季节的成年人。超过1的HI值表明与所检查的元素相关的明显的非致癌风险。这项研究的结果为PM2.5中重元素的行为和风险缓解提供了有价值的见解，有助于了解德里城市环境中的空气质量和公共卫生。
