Department of Environmental Science, College of Agriculture and Life Sciences, University of Arizona, Tucson, AZ, USA.
Sonora Environmental Research Institute, Inc., Tucson, AZ, USA.
J Environ Manage. 2023 Jul 1;337:117747. doi: 10.1016/j.jenvman.2023.117747. Epub 2023 Apr 3.
As climate change exacerbates water scarcity, rainwater harvesting for household irrigation and gardening becomes an increasingly common practice. However, the use and quality of harvested rainwater are not well studied, and the potential pollutant exposures associated with its use are generally unknown. There are currently no federal standards in the United States to assess metal(loid)s in harvested rainwater. Project Harvest, a community science research project, was created to address this knowledge gap and study the quality of harvested rainwater, primarily used for irrigation, in four environmental justice communities in Arizona, USA. Community scientists collected 577 unique rooftop harvested rainwater samples from 2017 to 2020, which were analyzed for metal(loid)s, where arsenic (As) concentrations ranged from 0.108 to 120 μg L and lead (Pb) concentrations ranged from 0.013 to 350 μg L and compared to relevant federal/state standards/recommendations. Community As and Pb concentrations decreased as: Hayden/Winkelman > Tucson > Globe/Miami > Dewey-Humboldt. Linear mixed models were used to analyze rooftop harvested rainwater data and results indicated that concentrations of As and Pb in the summer monsoon were significantly greater than winter; and contamination was significantly greater closer to extractive industrial sites in three of the four study communities (ASARCO Hayden Plant Superfund Alternative site in Hayden/Winkelman, Davis-Monthan United States Air Force Base in Tucson - Pb only, and Freeport McMoRan Copper and Gold Mine in Globe/Miami). Based on models, infrastructure such as proximity to roadway, roof material, presence of a cistern screen, and first-flush systems were not significant with respect to As and Pb when controlling for relevant spatiotemporal variables; whereas, cistern age was associated with Pb concentrations. These results however, indicate that concentrations vary seasonally and by proximity to industrial activity, not by decisions made regarding collection system infrastructures at the individual home level. This study shows that generally, individuals are not responsible for environmental contamination of rooftop harvested rainwater, rather activities and decisions of government and corporate industries control contaminant release.
随着气候变化加剧水资源短缺，家庭灌溉和园艺用雨水收集变得越来越普遍。然而，对雨水的使用和质量尚未进行充分研究，其使用相关的潜在污染物暴露情况通常也不为人知。目前美国没有联邦标准来评估雨水收集系统中的金属（类）物质。“丰收计划”（Project Harvest）是一个社区科学研究项目，旨在填补这一知识空白，并研究美国亚利桑那州四个环境正义社区中主要用于灌溉的雨水收集质量。社区科学家于 2017 年至 2020 年期间收集了 577 个独特的屋顶雨水收集样本，对其进行了金属（类）物质分析，砷（As）浓度范围为 0.108 至 120μg/L，铅（Pb）浓度范围为 0.013 至 350μg/L，并与相关联邦/州标准/建议进行了比较。社区的 As 和 Pb 浓度随着以下顺序而降低：海登/温克尔曼（Hayden/Winkelman）>图森（Tucson）>格罗夫/迈阿密（Globe/Miami）>迪威-洪堡（Dewey-Humboldt）。线性混合模型用于分析屋顶雨水收集数据，结果表明，夏季季风期间的 As 和 Pb 浓度明显高于冬季；并且在四个研究社区中的三个社区（海登/温克尔曼的 ASARCO 海登工厂超级基金替代场址、图森的戴维斯-蒙森美国空军基地——仅 Pb，以及格罗夫/迈阿密的自由港麦克莫兰铜金公司），靠近采矿业的地点的污染程度显著更高。基于模型，在控制相关时空变量的情况下，基础设施（如靠近道路、屋顶材料、蓄水池筛网的存在和首次冲洗系统）与 As 和 Pb 无关；而蓄水池的年龄与 Pb 浓度有关。然而，这些结果表明，浓度会随季节和与工业活动的距离而变化，而不是由个体家庭层面收集系统基础设施的决策决定。本研究表明，一般而言，个人无需对屋顶雨水收集的环境污染负责，而是政府和企业产业的活动和决策控制污染物的释放。
