Washington State University, Washington Stormwater Center, Puyallup Research & Extension Center, 2606 W. Pioneer Ave, Puyallup, WA 98371, USA.
Washington State University, Washington Stormwater Center, Puyallup Research & Extension Center, 2606 W. Pioneer Ave, Puyallup, WA 98371, USA.
Environ Pollut. 2019 Dec;255(Pt 2):113262. doi: 10.1016/j.envpol.2019.113262. Epub 2019 Sep 19.
Urban stormwater is a major source of chemical pollution to receiving waters. Anthropogenic materials in the built environment can be an important source of chemicals to stormwater runoff. Roofing materials can leach significant amounts of metals, which vary over the life of the roof. We report concentrations of three metals (As, Cu, Zn) leaching into runoff from experimental panels of 14 roofing materials over 4.5 years of weathering. Ten roofing materials leached metals. Several leached >10 ppb during one or more study periods. The most common correlate with metal concentration was panel age, followed by precipitation amount. Extrapolating from these observations, we estimated the loading of metals from each roofing material during the first 10 years following installation. Eight materials were predicted to leach metals above background at the end of the 10 years. In combination with information on the prevalence of different roofing materials in the Puget Sound region of the Pacific Northwest, we estimated the relative amount of metals contributed from roofing materials in this basin. Most arsenic and copper was estimated to be contributed by residential roofing; nearly all arsenic from wood shakes manufactured with copper chromated arsenic, and copper contributed mainly from treated wood shakes followed by copper granule-containing asphalt shingles. Most zinc was estimated to be contributed by commercial roofs, including Zincalume and painted metal roofs. Overall our data shows that roofing materials can be an important long-term source of As, Cu, and Zn to stormwater runoff. Compared with atmospheric deposition, roof materials were a significant source, particularly of As and Cu. To get a complete picture of metals sourced from buildings, there is a need to study whole roof systems, including gutters, downspouts, and HVAC systems, as well as metals contributed from homeowner-applied treatments to their roofs.
城市雨水是受纳水体化学污染的主要来源。建筑环境中的人为物质可能是雨水径流水化学污染物的重要来源。屋顶材料会浸出大量金属，其浓度随屋顶寿命而变化。我们报告了在 4.5 年的风化过程中，从 14 种屋顶材料的实验板中浸出的三种金属（As、Cu、Zn）进入径流水的浓度。十种屋顶材料浸出金属。在一个或多个研究期间，有几种材料浸出量超过 10 ppb。与金属浓度最相关的是面板年龄，其次是降水量。根据这些观察结果推断，我们估算了每种屋顶材料在安装后的头 10 年中金属的排放量。预计 8 种材料在 10 年后会将金属浸出到背景值以上。结合太平洋西北地区普吉特海湾地区不同屋顶材料的流行情况，我们估算了该流域内屋顶材料贡献的金属相对量。据估计，砷和铜的大部分来自住宅屋顶；几乎所有来自含铜铬砷木瓦的砷，而铜主要来自经过处理的木瓦，其次是含铜颗粒的沥青瓦。锌估计主要来自商业屋顶，包括锌铝和涂漆金属屋顶。总体而言，我们的数据表明，屋顶材料可能是雨水径流水体中 As、Cu 和 Zn 的重要长期来源。与大气沉降相比，屋顶材料是一个重要的来源，特别是对 As 和 Cu 而言。为了全面了解建筑材料中的金属来源，需要研究整个屋顶系统，包括排水沟、落水管和暖通空调系统，以及房主对其屋顶应用处理措施所贡献的金属。
