Oyewumi Oluyinka, Feldman Jonathan, Gourley Jonathan R
Department of Geological Sciences, Central Connecticut State University, 1615 Stanley Street, New Britain, CT, 06050, USA.
Department of Environmental Sciences, Trinity College, Hartford, CT, 06106, USA.
Environ Monit Assess. 2017 Apr;189(4):141. doi: 10.1007/s10661-017-5856-z. Epub 2017 Mar 3.
Recent arsenic pollution of drinking-water wells across Lebanon, northeastern USA has led to a growing concern about possible impact of agricultural activities on the hydrologic system. This study assessed the concentrations and distributions of arsenic and ten other elements (Al, Cd, Cr, Cu, Fe, K, Mn, P, Pb, and Zn) in stream sediments. The overall goal is to determine the extent of these elements within the fluvial systems, as well as overall sediment quality. A total of 65 stream sediments samples were collected, and analyzed for particle size distributions, organic matter contents, trace, and major elements concentrations. Results showed spatial variability in the concentrations of trace elements due to variation in sediments grain sizes, organic matter content, as well as land use activities within the study area. Calculation of sediment enrichment with respect to As, Cd, Cr, Cu, Mn, Pb, and Zn showed that about 48-52% of all the sampling locations are not enriched, nevertheless, approximately 2-11% of all the sampling locations are significantly enriched, an indication of anthropogenic input. However, results of ecological risk assessment showed no connection with sediment enrichment as most sampling locations have concentrations below the threshold probable effect concentration (PEC) value. Statistical analysis using principal component analysis (PCA) extracted three significant components explaining over 72% of total variance covering elements having origin in both natural and anthropogenic sources, thus suggesting that the concentrations and distribution of these elements within stream sediments are related to a combination of weathering processes on the bedrock geology, and anthropogenic activities.
近期，黎巴嫩和美国东北部地区饮用水井的砷污染问题引发了人们对农业活动可能对水文系统造成影响的日益关注。本研究评估了河流沉积物中砷及其他十种元素（铝、镉、铬、铜、铁、钾、锰、磷、铅和锌）的浓度和分布情况。总体目标是确定这些元素在河流系统中的含量范围以及沉积物的整体质量。共采集了65个河流沉积物样本，并对其粒度分布、有机质含量、微量元素和主要元素浓度进行了分析。结果表明，由于研究区域内沉积物粒度、有机质含量以及土地利用活动的差异，微量元素浓度存在空间变异性。对砷、镉、铬、铜、锰、铅和锌的沉积物富集计算表明，约48 - 52%的采样点未出现富集现象，然而，约2 - 11%的采样点有显著富集，这表明存在人为输入。然而，生态风险评估结果显示，由于大多数采样点的浓度低于阈值效应浓度（PEC）值，因此与沉积物富集无关。使用主成分分析（PCA）进行的统计分析提取了三个显著成分，解释了总方差的72%以上，涵盖了源于自然和人为来源的元素，这表明这些元素在河流沉积物中的浓度和分布与基岩地质的风化过程和人为活动的综合作用有关。
