Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China.
Guangdong Provincial Key Laboratory of Petrochemical Pollution Processes and Control, School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming 525000, China.
Int J Environ Res Public Health. 2023 Jan 31;20(3):2520. doi: 10.3390/ijerph20032520.
Traffic activities release large amounts of trace metal(loid)s in urban environments. However, the impact of vehicle operation-associated emissions on trace metal(loid) enrichment in road dust and the potential migration of these trace metal(loid)s to the surrounding environment remain unclear. We evaluated the contamination, sequential fraction, and bioaccessibility of trace metal(loid)s in urban environments by assessing their presence in road dust, garden vegetables, and tree tissues, including bark and aerial roots, at a traffic-training venue impacted by vehicle operation emissions and, finally, calculated the bioaccessibility-based health risk. The results indicated a significant accumulation of trace metal(loid)s in road dust, with the highest lead (Pb), cadmium (Cd), and antimony (Sb) concentrations in the garage entrance area due to higher vehicle volumes, frequent vehicle starts and stops, and lower speeds. Aerial roots exposed to hill start conditions exhibited the highest Pb, Zn, and Sb levels, potentially caused by high road dust resuspension, confirming that this tree tissue is an appropriate bioindicator. Sequential extraction revealed high percentages of carbonate-, Fe/Mn oxide-, and organic/sulphide-associated fractions of Pb, copper (Cu), and zinc (Zn) in road dust, while most Cd, Cr, Ni, and Sb occurred as residual fractions. According to the potential mobilizable fractions in sequential extraction, the in vitro gastrointestinal method could be more suitable than the physiologically based extraction test to evaluate the bioaccessibility-related risk of traffic-impacted road dust. The bioaccessibility-based health risk assessment of the road dust or soil confirmed no concern about noncarcinogenic risk, while the major risk originated from Pb although leaded gasoline was prohibited before the venue establishment. Furthermore, the cancer risks (CRs) analysis showed the probable occurrence of carcinogenic health effects from Cd and Ni to adults and from Cd, Cr, and Ni to children. Furthermore, the Cd and Pb concentrations in the edible leaves of cabbage and radish growing in gardens were higher than the recommended maximum value. This study focused on the health risks of road dust directly impacted by vehicle emissions and provides accurate predictions of trace metal(loid) contamination sources in the urban environment.
交通活动会在城市环境中释放大量痕量金属（类金属）。然而，车辆运行相关排放对道路灰尘中痕量金属（类金属）富集的影响以及这些痕量金属（类金属）向周围环境迁移的潜力仍不清楚。我们通过评估道路灰尘、花园蔬菜和树木组织（包括树皮和气生根）中痕量金属（类金属）的存在，评估了交通培训场地受车辆运行排放影响的城市环境中的污染、顺序分数和生物可利用性，并最终计算了基于生物可利用性的健康风险。结果表明，道路灰尘中痕量金属（类金属）的积累显著，由于车辆数量较高、车辆频繁启动和停止以及速度较低，车库入口区域的铅（Pb）、镉（Cd）和锑（Sb）浓度最高。暴露于斜坡起动条件下的气生根表现出最高的 Pb、Zn 和 Sb 水平，可能是由于道路灰尘再悬浮较高所致，证实该树木组织是一种合适的生物标志物。顺序提取显示，道路灰尘中 Pb、Cu 和 Zn 的碳酸盐、Fe/Mn 氧化物和有机/硫化物结合分数的百分比较高，而大多数 Cd、Cr、Ni 和 Sb 则以残余分数存在。根据顺序提取中可移动的潜在分数，体外胃肠道法可能比基于生理学的提取试验更适合评估受交通影响的道路灰尘的生物可利用性相关风险。道路灰尘或土壤的生物可利用性风险评估确认了非致癌风险没有问题，尽管在场地建立之前已禁止使用含铅汽油，但主要风险仍来自 Pb。此外，致癌风险（CR）分析表明，成人可能会因 Cd 和 Ni 而发生致癌健康影响，儿童可能会因 Cd、Cr 和 Ni 而发生致癌健康影响。此外，生长在花园中的白菜和萝卜的可食用叶片中的 Cd 和 Pb 浓度高于建议的最大值。本研究重点关注受车辆排放直接影响的道路灰尘的健康风险，并为城市环境中痕量金属（类金属）污染来源提供了准确的预测。
