School of Environmental Studies, Jadavpur University, Kolkata, India.
School of Environmental Studies, Jadavpur University, Kolkata, India; Earth Observatory of Singapore, Nanyang Technological University, Singapore.
Chemosphere. 2022 Nov;307(Pt 4):136029. doi: 10.1016/j.chemosphere.2022.136029. Epub 2022 Aug 23.
Southeast Asia has become a hotspot of anthropogenic particulate matter (PM) emissions due to increased coal combustion, high-temperature industrial operations, vehicular traffic, and agricultural biomass burning. Lead (Pb), a criteria pollutant, bound to such PM can be hazardous when inhaled, even at extremely low concentrations. Precise and accurate source apportionment of atmospheric Pb is thus, critical in order to minimize its exposure. This study investigates the sources of atmospheric Pb in Singapore aerosol samples (PM) using Pb isotopes and elemental composition as tracers of contamination sources. PM aerosol sampling was conducted over a period of 1 year from June 2017 to May 2018 to capture the seasonal variations in sources of atmospheric Pb. Elemental concentrations reveal particularly high enrichment factors for Pb, Cu, V, Ni and Zn, especially when under the influence of southwest (SW) and inter monsoon (IM) winds. Pb isotopic ratios across the three seasons (Pb = 1.147-1.150 and Pb = 2.420-2.428) are not significantly different. The Pb isotopic signatures and V/Ni ratios for all three seasons overlap with those of gasoline, diesel and ship emissions. Moreover, V/Pb values of more than unity for SW and IM winds suggest influence of transboundary coal combustion emissions particularly from Indonesia. Consequently, using Pb isotopic fingerprints and elemental ratios, we find that the primary sources of atmospheric Pb are vehicular & ship emissions, heavy oil combustion, transboundary coal combustion emissions, waste incineration and recirculation of historic leaded gasoline.
由于煤炭燃烧、高温工业作业、交通车辆以及农业生物质燃烧等因素的增加，东南亚已成为人为颗粒物（PM）排放的热点地区。与这些 PM 结合的铅（Pb）作为一种标准污染物，即使在极低的浓度下，吸入也会造成危害。因此，精确而准确地对大气 Pb 的来源进行分配，对于最小化其暴露风险至关重要。本研究利用 Pb 同位素和元素组成作为污染来源的示踪剂，调查了新加坡气溶胶样品（PM）中大气 Pb 的来源。从 2017 年 6 月到 2018 年 5 月，进行了为期一年的 PM 气溶胶采样，以捕捉大气 Pb 来源的季节性变化。元素浓度显示 Pb、Cu、V、Ni 和 Zn 的富集因子特别高，尤其是在西南（SW）和季风间歇（IM）风的影响下。三个季节的 Pb 同位素比值（Pb=1.147-1.150 和 Pb=2.420-2.428）没有显著差异。所有三个季节的 Pb 同位素特征和 V/Ni 比值与汽油、柴油和船舶排放的特征相似。此外，SW 和 IM 风的 V/Pb 值大于 1，表明存在跨境煤炭燃烧排放的影响，特别是来自印度尼西亚的影响。因此，利用 Pb 同位素指纹和元素比值，我们发现大气 Pb 的主要来源是车辆和船舶排放、重油燃烧、跨境煤炭燃烧排放、废物焚烧和含铅汽油的再循环。
