Dietrich Matthew, Rader Shelby T, Filippelli Gabriel M
Department of Earth Sciences, Indiana University - Purdue University Indianapolis, Indianapolis, IN, USA.
Department of Earth and Atmospheric Sciences, Indiana University, Bloomington, IN, USA.
Environ Sci Pollut Res Int. 2023 Jan;30(2):4269-4277. doi: 10.1007/s11356-022-22561-4. Epub 2022 Aug 15.
Heavy metal contamination in urban environments, particularly lead (Pb) pollution, is a health hazard both to humans and ecological systems. Despite wide recognition of urban metal pollution in many cities, there is still relatively limited research regarding heavy metal distribution and transport at the household-scale between soils and indoor dusts-the most important scale for actual human interaction and exposure. Thus, using community-scientist-generated samples in Indianapolis, IN (USA), we applied bulk chemistry, Pb isotopes, and scanning electron microscopy (SEM) to illustrate how detailed analytical techniques can aid in interpretation of Pb pollution distribution at the household-scale. Our techniques provide definitive evidence for Pb paint sourcing in some homes, while others may be polluted with Pb from past industrial/vehicular sources. SEM revealed anthropogenic particles suggestive of Pb paint and the widespread occurrence of Fe-rich metal anthropogenic spherules across all homes, indicative of pollutant transport processes. The variability of Pb pollution at the household scale evident in just four homes is a testament to the heterogeneity and complexity of urban pollution. Future urban pollution research efforts would do well to utilize these more detailed analytical methods on community-sourced samples to gain better insight into where the Pb came from and how it currently exists in the environment. However, these methods should be applied after large-scale pollution screening techniques such as portable X-ray fluorescence (XRF), with more detailed analytical techniques focused on areas where bulk chemistry alone cannot pinpoint dominant pollution mechanisms and where community scientists can also give important metadata to support geochemical interpretations.
城市环境中的重金属污染，尤其是铅（Pb）污染，对人类和生态系统均构成健康危害。尽管许多城市对城市金属污染已有广泛认识，但关于土壤和室内灰尘之间家庭尺度的重金属分布与迁移的研究仍相对有限，而家庭尺度是实际人类接触和暴露的最重要尺度。因此，我们利用美国印第安纳州印第安纳波利斯市社区科学家采集的样本，应用整体化学、铅同位素和扫描电子显微镜（SEM）来说明详细的分析技术如何有助于解释家庭尺度的铅污染分布。我们的技术为一些家庭中铅漆的来源提供了确凿证据，而其他家庭可能受到过去工业/车辆来源的铅污染。扫描电子显微镜揭示了表明铅漆的人为颗粒以及所有家庭中普遍存在的富含铁的金属人为小球，这表明了污染物的迁移过程。仅在四个家庭中就明显存在的家庭尺度铅污染的变异性，证明了城市污染的异质性和复杂性。未来的城市污染研究工作最好对社区来源的样本采用这些更详细的分析方法，以便更好地了解铅的来源以及它目前在环境中的存在方式。然而，这些方法应在便携式X射线荧光（XRF）等大规模污染筛查技术之后应用，更详细的分析技术应集中在仅靠整体化学无法确定主要污染机制的区域，以及社区科学家也能提供重要元数据以支持地球化学解释的区域。
