Nord Mari A, Maier Michelle A, Bijak Alexandra L, Crane Judy L, Pollard Amina I
Region 5, U.S. Environmental Protection Agency, 77 West Jackson Boulevard, Chicago, IL 60604, USA.
U.S. Environmental Protection Agency, 1301 Constitution Avenue Northwest, Washington, DC 20460, USA.
Sci Total Environ. 2024 Dec 15;956:177315. doi: 10.1016/j.scitotenv.2024.177315. Epub 2024 Nov 9.
This study provides the largest sediment quality assessment of lakes in the conterminous United States (U.S.). A variety of lakes (n = 1005) were selected based on the randomized, probabilistic sampling design of the broader 2017 National Lakes Assessment study. Surficial sediment samples (0-5 cm) were collected at one representative site (generally the deepest point) for each lake (n = 969). The samples were analyzed for 16 metal(loid)s, 25 polycyclic aromatic hydrocarbons (PAHs), 53 polychlorinated biphenyl (PCB) congeners, 27 legacy pesticides and metabolites, total organic carbon, and grain size. Metal(loid)s and PAHs were widely distributed due to natural and potential anthropogenic sources, with regional variations observed for lakes in the nine ecoregions encompassing the U.S. Most sites did not have detectable PCB congeners or legacy pesticides. An integrative chemical index of mean probable effect concentration quotients, composed of seven metal(loid)s and ƩPAH, was used to assess sediment quality for the estimated population of 224,916 lakes in the conterminous U.S. Nationally, 26.5% (CI of 20-33%) of lakes were in good condition (corresponding to predicted low incidences of toxicity to benthic organisms), 69.3% (CI of 63-76%) of lakes were in fair condition, and 1.8% (CI of 0.6-3%) of lakes were in poor condition (corresponding to predicted high incidences of sediment toxicity). Unweighted metal(loid) and ƩPAH concentrations were compared to lake, watershed, and land use data. Deeper lakes were significantly more contaminated (or naturally enriched) with As, Cd, Cu, Pb, Hg, Zn, and ƩPAH than shallow lakes. Lakes at lower elevation were also associated with more contamination (or natural enrichment) of As, Cr, Pb, Hg, Ni, Zn, and ƩPAH than higher elevation lakes. Greater contamination was associated with watersheds containing larger percentages of developed land. This study demonstrates an approach which can be used by others to assess sediment quality in their jurisdictions.
本研究对美国本土的湖泊进行了规模最大的沉积物质量评估。根据2017年更广泛的全国湖泊评估研究的随机概率抽样设计，选取了各类湖泊（n = 1005）。在每个湖泊的一个代表性地点（通常是最深点）采集表层沉积物样本（0 - 5厘米）（n = 969）。对样本分析了16种金属（类金属）、25种多环芳烃（PAH）、53种多氯联苯（PCB）同系物、27种遗留农药及其代谢物、总有机碳和粒度。由于自然和潜在的人为来源，金属（类金属）和多环芳烃分布广泛，在美国的九个生态区域的湖泊中观察到了区域差异。大多数地点未检测到多氯联苯同系物或遗留农药。使用由七种金属（类金属）和总多环芳烃组成的平均可能效应浓度商的综合化学指数，对美国本土估计的224,916个湖泊的沉积物质量进行评估。在全国范围内，26.5%（置信区间为20 - 33%）的湖泊状况良好（对应于对底栖生物毒性发生率较低的预测），69.3%（置信区间为63 - 76%）的湖泊状况一般，1.8%（置信区间为0.6 - 3%）的湖泊状况较差（对应于沉积物毒性发生率较高 的预测）。将未加权的金属（类金属）和总多环芳烃浓度与湖泊、流域和土地利用数据进行了比较。较深的湖泊中，砷、镉、铜、铅、汞、锌和总多环芳烃的污染（或自然富集）程度明显高于浅湖。海拔较低的湖泊中，砷、铬、铅、汞、镍、锌和总多环芳烃的污染（或自然富集）程度也高于海拔较高的湖泊。污染程度较高与开发土地所占百分比更大的流域相关。本研究展示了一种可供其他人用于评估其管辖范围内沉积物质量的方法。
