University of Wisconsin, Madison, Department of Soil Science, 263 King Hall 1525 Observatory Drive, Madison, WI, 53706, USA.
Wisconsin Department of Health Services, Bureau of Environmental and Occupational Health, Madison, WI, USA.
Environ Pollut. 2021 Jan 1;268(Pt B):115772. doi: 10.1016/j.envpol.2020.115772. Epub 2020 Oct 6.
Inputs of polycyclic aromatic hydrocarbons (PAHs) of regulatory interest from diffuse atmospheric sources within urban areas frequently elevate local soil concentrations to levels requiring remediation despite the lack of in-situ contamination. This research sought to determine the distribution and potential health effects of aerially deposited PAHs in soil within the urban core of metropolitan Milwaukee, Wisconsin, U.S.A. as part of a soil regulatory standards reevaluation. Park areas (n = 27) identified as undisturbed for 80+ years, containing no fill material, and receiving only atmospheric deposition were selected for composite surface and 92 cm core soil sample collection (n = 295). Samples were analyzed for the 16 USEPA priority PAHs, 1- and 2- methylnapthalene and ancillary soil properties. Soil core and ancillary data confirm lack of site disturbance. PAH diagnostic ratios and homologue summations indicate that diffuse multiple point source emissions contribute equally to PAH deposition throughout the area. Benzo(a)pyrene (BaP) and dibenz(a,h)anthracene mean concentrations exceed health-based clean up levels. Risk assessment shows only a worst-case exposure scenario (BaP at the 95% upper confidence limit) increasing cancer risk (1.67 × 10) over current regulatory thresholds (1.0 × 10). Health quotients show potential health risks from fluoranthene and pyrene for daily park users and from BaP for all others. Mean soil PAH values are similar to New Orleans, but lower than Chicago, Boston, and London reflecting industrial history and site selection protocols. The soil PAH results presented here for sites selected for non-manipulated soils combined with an almost 100-year uninterrupted atmospheric exposure effectively show the maximum potential PAH values that can be found at any given undisturbed location within the Milwaukee urban core due solely to atmospheric deposition.
来自城市地区漫散大气源的具有监管意义的多环芳烃（PAHs）输入物经常会使当地土壤浓度升高到需要修复的水平，尽管不存在原地污染。这项研究旨在确定美国威斯康星州密尔沃基都会区城市核心内空气沉积 PAHs 在土壤中的分布和潜在健康影响，作为土壤监管标准重新评估的一部分。选择了 80 多年来未被干扰、不含填充材料且仅接受大气沉积的公园区域（n=27）进行复合表面和 92cm 土壤芯样品采集（n=295）。对 16 种美国环保署优先 PAHs、1-和 2-甲基萘以及辅助土壤特性进行了分析。土壤芯和辅助数据证实了场地未受干扰。PAH 诊断比和同系物总和表明，漫散多点源排放对整个地区的 PAH 沉积具有同等贡献。苯并(a)芘（BaP）和二苯并(a,h)蒽的平均浓度超过基于健康的清理水平。风险评估显示，仅在最坏情况下的暴露情景（BaP 在 95%置信上限）下，癌症风险（当前监管阈值 1.0×10 的 1.67×10）才会增加。健康商数显示，对于日常使用公园的人来说，荧蒽和芘可能存在健康风险，而对于其他人来说，BaP 可能存在健康风险。与新奥尔良相比，土壤中 PAH 的平均值相似，但低于芝加哥、波士顿和伦敦，这反映了工业历史和选址协议。这里为非人为干预土壤选择的地点提出的土壤 PAH 结果，结合近 100 年不间断的大气暴露，有效地展示了在密尔沃基城市核心区任何给定未受干扰地点仅因大气沉积而可能存在的最大潜在 PAH 值。
