Hesterberg Dean, Polizzotto Matthew L, Crozier Carl, Austin Robert E
Department of Soil Science, North Carolina State University, Raleigh, North Carolina, USA.
Integr Environ Assess Manag. 2016 Apr;12(2):353-63. doi: 10.1002/ieam.1669. Epub 2015 Sep 8.
Catastrophic events require rapid, scientifically sound decision making to mitigate impacts on human welfare and the environment. The objective of this study was to analyze potential impacts of coal ash-derived trace elements on agriculture following a 35,000-tonne release of coal ash into the Dan River at the Duke Energy Steam Station in Eden, North Carolina. We performed scenario calculations to assess the potential for excessive trace element loading to soils via irrigation and flooding with Dan River water, uptake of trace elements by crops, and livestock consumption of trace elements via drinking water. Concentrations of 13 trace elements measured in Dan River water samples within 4 km of the release site declined sharply after the release and were equivalent within 5 d to measurements taken upriver. Mass-balance calculations based on estimates of soil trace-element concentrations and the nominal river water concentrations indicated that irrigation or flooding with 25 cm of Dan River water would increase soil concentrations of all trace elements by less than 0.5%. Calculations of potential increases of trace elements in corn grain and silage, fescue, and tobacco leaves suggested that As, Cr, Se, Sr, and V were elements of most concern. Concentrations of trace elements measured in river water following the ash release never exceeded adopted standards for livestock drinking water. Based on our analyses, we present guidelines for safe usage of Dan River water to diminish negative impacts of trace elements on soils and crop production. In general, the approach we describe here may serve as a basis for rapid assessment of environmental and agricultural risks associated with any similar types of releases that arise in the future.
灾难性事件需要迅速做出科学合理的决策，以减轻对人类福祉和环境的影响。本研究的目的是分析在北卡罗来纳州伊登市杜克能源蒸汽电站向丹河排放35000吨煤灰后，煤灰中痕量元素对农业的潜在影响。我们进行了情景计算，以评估通过用丹河水灌溉和洪水导致土壤中痕量元素过量负载的可能性、作物对痕量元素的吸收以及牲畜通过饮用水摄入痕量元素的情况。在排放点4公里范围内采集的丹河水样中测得的13种痕量元素浓度在排放后急剧下降，5天内就与上游的测量值相当。基于土壤痕量元素浓度估计和标称河水浓度的质量平衡计算表明，用25厘米深的丹河水灌溉或洪水将使所有痕量元素在土壤中的浓度增加不到0.5%。对玉米籽粒和青贮饲料、羊茅和烟叶中痕量元素潜在增加量的计算表明，砷、铬、硒、锶和钒是最值得关注的元素。煤灰排放后河水中测得痕量元素的浓度从未超过牲畜饮用水的采用标准。基于我们的分析，我们提出了安全使用丹河水的指导方针，以减少痕量元素对土壤和作物生产的负面影响。一般来说，我们在此描述的方法可作为快速评估未来出现的任何类似类型排放所带来的环境和农业风险的基础。
