Office of Research and Development, National Health and Environmental Effects Laboratory, Atlantic Ecology Division, US Environmental Protection Agency, 27 Tarzwell Drive, Narragansett, RI, USA.
Environ Monit Assess. 2012 Dec;184(12):7531-50. doi: 10.1007/s10661-012-2517-0. Epub 2012 Jan 28.
New Bedford Harbor (NBH), located in southeastern Massachusetts, was designated as a marine Superfund site in 1983 due to sediment contamination by polychlorinated biphenyls (PCBs). Based on risks to human health and the environment, the first two phases of the site cleanup involved dredging PCB-contaminated sediments from the harbor. Therefore, a long-term monitoring program (LTM) was developed to measure spatial and temporal chemical and biological changes in sediment, water, and biota to assess the effects and effectiveness of the remedial activities. A systematic, probabilistic sampling design was used to select sediment sampling stations. This unbiased design allowed the three segments of the harbor to be compared spatially and temporally to quantify changes resulting from dredging the contaminated sediments. Sediment was collected at each station, and chemical (e.g., PCBs and metals), physical (e.g., grain size), and biological (e.g., benthic community) measurements were conducted on all samples. This paper describes the overall NBH-LTM approach and the results from the five rounds of sample collections. There is a decreasing spatial gradient in sediment PCB concentrations from the northern boundary (upper harbor) to the southern boundary (outer harbor) of the site. Along this same transect, there is an increase in biological condition (e.g., benthic community diversity). Temporally, the contaminant and biological gradients have been maintained since the 1993 baseline collection; however, since the onset of full-scale remediation, PCB concentrations have decreased throughout the site, and one of the benthic community indices has shown significant improvement in the lower and outer harbor areas.
新贝德福德港（NBH）位于马萨诸塞州东南部，由于多氯联苯（PCBs）污染的沉积物，于 1983 年被指定为海洋超级基金站点。基于对人类健康和环境的风险，该场地清理的前两个阶段涉及从港口疏浚 PCB 污染的沉积物。因此，制定了一个长期监测计划（LTM），以测量沉积物、水和生物群中的时空化学和生物变化，评估补救活动的效果。采用系统的、概率抽样设计来选择沉积物采样站。这种无偏设计允许从空间和时间上比较港口的三个部分，以量化疏浚受污染沉积物所产生的变化。在每个站点采集沉积物，并对所有样品进行化学（例如，PCBs 和金属）、物理（例如，粒度）和生物（例如，底栖群落）测量。本文描述了总体 NBH-LTM 方法以及五轮样本采集的结果。从该地点的北部边界（上港）到南部边界（外港），沉积物中 PCB 浓度呈递减的空间梯度。沿着这条相同的横断面，生物状况（例如，底栖群落多样性）有所增加。从时间上看，自 1993 年基线采集以来，污染物和生物梯度一直保持不变；然而，自全面修复开始以来，整个场地的 PCB 浓度已经下降，并且其中一个底栖群落指数在下游和外港地区显示出显著改善。
