Department of Earth and Environmental Sciences, Vanderbilt University, 5726 Stevenson Center, 7th floor, Nashville, TN 37240, United States.
Department of Geology & Environmental Earth Science, Miami University, 250 S. Patterson Avenue, 118 Shideler Hall, Oxford, OH 45056, United States.
Environ Int. 2019 Jul;128:175-192. doi: 10.1016/j.envint.2019.04.042. Epub 2019 May 3.
An investigation of road sediment in Gary, Indiana revealed high levels of various trace metals such as Zn, Mn, and Cr, often exceeding those of background reference concentrations as shown through geoaccumulation indices and contamination factors. The hazard index (HI) value for Mn in children was >1 (1.7), suggesting possible long-term non-carcinogenic health risk. Mn HI for children is even higher for the five samples closest to a US Steel facility, with an HI of 2.8. Through SEM-EDS analysis, the prevalence of small particulates (PM and PM) containing potentially harmful elements such as Mn and Pb illustrate a health risk through direct inhalation or ingestion. The small nature of particulates in general may also pose an increased health risk for respiratory diseases such as asthma. Mn concentrations in the road sediment were particularly high, with 30 out of 32 samples exceeding 1800 ppm. Mn and V concentrations show a strong spatial trend of decreasing concentration away from a US Steel facility. These spatial trends along with correlation plots of the bulk chemistry suggest that industrial steel manufacturing, particularly US Steel in Gary, is a major contributing source of Mn and V. Fe and Cr show a moderate decrease in concentrations away from the US Steel facility, which suggests some sourcing from the steel facility when coupled with bulk chemistry plots. Zn and Cu do not show much evidence of sourcing from the US Steel facility, likely due to increased mixing from other sources. Further work constraining anthropogenic sources, the bioaccessible fraction of metals, and analysis of direct atmospheric particulates can help with remedial activity and risk assessment.
对印第安纳州加里市道路沉积物的调查显示，各种痕量金属（如 Zn、Mn 和 Cr）的含量很高，通常超过背景参考浓度，这可以通过地质累积指数和污染因子来证明。儿童体内 Mn 的危害指数 (HI) 值大于 1（1.7），表明可能存在长期的非致癌健康风险。对于距离美国钢铁厂最近的五个样本，儿童体内 Mn 的 HI 值甚至更高，为 2.8。通过扫描电子显微镜-能谱分析（SEM-EDS），发现含有 Mn 和 Pb 等潜在有害元素的小颗粒（PM 和 PM）很普遍，这说明通过直接吸入或摄入会对健康造成危害。一般来说，颗粒物的微小性质也可能对哮喘等呼吸道疾病构成更高的健康风险。道路沉积物中的 Mn 浓度特别高，32 个样本中有 30 个超过 1800ppm。Mn 和 V 的浓度呈现出远离美国钢铁厂浓度降低的强烈空间趋势。这些空间趋势以及总体化学特征的相关图表明，工业钢铁制造，特别是加里的美国钢铁，是 Mn 和 V 的主要来源。Fe 和 Cr 的浓度远离美国钢铁厂呈适度降低，这表明与总体化学特征图结合时，一些来源来自钢铁厂。Zn 和 Cu 没有显示出太多来自美国钢铁厂的来源，可能是由于其他来源的混合增加。进一步限制人为来源、金属的生物可利用部分以及直接大气颗粒物的分析工作，可以有助于补救活动和风险评估。
