Earth and Environmental Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, New South Wales, 2109, Australia.
Earth and Environmental Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, New South Wales, 2109, Australia.
Environ Pollut. 2022 Jan 15;293:118462. doi: 10.1016/j.envpol.2021.118462. Epub 2021 Nov 4.
Trace metal exposure from environmental sources remains a persistent global problem, particularly in communities residing adjacent to metal extraction and processing industries. This study examines front yard soil and house dust from 62 residences throughout the Australian Ag-Pb-Zn mining city of Broken Hill to better understand spatial variability in metal distributions, compositions and exposures across an industrially polluted urban environment. X-ray fluorescence analysis of paired soil/dust samples indicated that geomean concentrations (mg/kg) of Cu (32/113), Zn (996/1852), As (24/34) and Pb (408/587) were higher in house dust while Ti (4239/3660) and Mn (1895/1101) were higher in outdoor soil. Ore associated metals and metalloids (Mn, Zn, As, Pb) in soil and house dust were positively correlated and declined in concentration away from mining areas, the primary source of metalliferous emissions in Broken Hill. The rate of decline was not equivalent between soil and house dust, with the indoor/outdoor concentration ratio increasing with distance from mining areas for Zn/Pb (geomean = 1.25/1.05 (<1 km); 2.14/1.52 (1-2 km); 2.54/2.04 (>2 km)). House dust and Broken Hill ore Pb isotopic compositions (Pb/Pb; Pb/Pb) were more similar in homes nearest to mining areas than those further away (geomean apportioned ore Pb = 88% (<1 km); 76% (1-2 km); 66% (>2 km)), reflecting spatial shifts in the balance of sources contributing to indoor contamination. Incorporation of house dust Pb reduced overestimation of IEUBK modelled blood Pb concentrations compared to when only soil Pb was used. These findings demonstrate that even in contexts where the source and environmental burden of metals are relatively apparent, geochemical relationships and exposures between outdoor and indoor environments are not always predictable, nor easily disaggregated.
从环境来源摄入痕量金属仍然是一个持续存在的全球性问题，特别是在紧邻金属开采和加工行业的社区中。本研究通过分析澳大利亚阿伯丁-铅-锌矿区破碎山（Broken Hill）62 个住宅的前院土壤和房屋灰尘，以更好地了解在工业污染的城市环境中金属分布、组成和暴露的空间变异性。对配对土壤/灰尘样本进行 X 射线荧光分析表明，室内灰尘中铜（32/113）、锌（996/1852）、砷（24/34）和铅（408/587）的地球均值浓度更高，而户外土壤中钛（4239/3660）和锰（1895/1101）的浓度更高。土壤和房屋灰尘中的矿石相关金属和类金属（锰、锌、砷、铅）呈正相关，且远离矿区，即破碎山富含金属排放的主要来源，浓度逐渐降低。土壤和房屋灰尘中浓度下降的速度并不相同，室内/室外浓度比随着与矿区的距离增加而增加，对于锌/铅（地球均值为 1.25/1.05（<1 公里）；2.14/1.52（1-2 公里）；2.54/2.04（>2 公里））。距离矿区最近的房屋灰尘和破碎山矿石铅同位素组成（Pb/Pb；Pb/Pb）与距离矿区较远的房屋灰尘和破碎山矿石铅同位素组成更为相似（地球均值分配矿石铅为 88%（<1 公里）；76%（1-2 公里）；66%（>2 公里）），反映了室内污染来源平衡的空间变化。与仅使用土壤铅相比，纳入房屋灰尘中的铅可以减少 IEUBK 模型预测的血液铅浓度的高估。这些发现表明，即使在金属来源和环境负担相对明显的情况下，室外和室内环境之间的地球化学关系和暴露也并不总是可以预测的，也不容易分解。
