Haack Sheridan K, Duris Joseph W, Fogarty Lisa R, Kolpin Dana W, Focazio Michael J, Furlong Edward T, Meyer Michael T
U.S. Geological Survey, 6520 Mercantile Way, Suite 5, Lansing, MI 48911, USA.
J Environ Qual. 2009 Jan 13;38(1):248-58. doi: 10.2134/jeq2008.0173. Print 2009 Jan-Feb.
The objective of this study was to compare fecal indicator bacteria (FIB) (fecal coliforms, Escherichia coli [EC], and enterococci [ENT]) concentrations with a wide array of typical organic wastewater chemicals and selected bacterial genes as indicators of fecal pollution in water samples collected at or near 18 surface water drinking water intakes. Genes tested included esp (indicating human-pathogenic ENT) and nine genes associated with various animal sources of shiga-toxin-producing EC (STEC). Fecal pollution was indicated by genes and/or chemicals for 14 of the 18 tested samples, with little relation to FIB standards. Of 13 samples with <50 EC 100 mL(-1), human pharmaceuticals or chemical indicators of wastewater treatment plant effluent occurred in six, veterinary antibiotics were detected in three, and stx1 or stx2 genes (indicating varying animal sources of STEC) were detected in eight. Only the EC eaeA gene was positively correlated with FIB concentrations. Human-source fecal pollution was indicated by the esp gene and the human pharmaceutical carbamazepine in one of the nine samples that met all FIB recreational water quality standards. Escherichia coli rfbO157 and stx2c genes, which are typically associated with cattle sources and are of potential human health significance, were detected in one sample in the absence of tested chemicals. Chemical and gene-based indicators of fecal contamination may be present even when FIB standards are met, and some may, unlike FIB, indicate potential sources. Application of multiple water quality indicators with variable environmental persistence and fate may yield greater confidence in fecal pollution assessment and may inform remediation decisions.
本研究的目的是比较18个地表水饮用水取水口处或其附近采集的水样中粪便指示菌（FIB）（粪大肠菌群、大肠杆菌[EC]和肠球菌[ENT]）的浓度与一系列典型有机废水化学物质及选定细菌基因，以此作为粪便污染的指标。检测的基因包括esp（指示人类致病性肠球菌）以及9个与产志贺毒素大肠杆菌（STEC）的各种动物来源相关的基因。18个检测样本中有14个样本的基因和/或化学物质表明存在粪便污染，这与FIB标准关系不大。在13个EC浓度<50 CFU/100 mL的样本中，有6个样本检测到人类药物或污水处理厂出水的化学指标，3个样本检测到兽用抗生素，8个样本检测到stx1或stx2基因（指示STEC的不同动物来源）。只有EC的eaeA基因与FIB浓度呈正相关。在9个符合所有FIB娱乐用水水质标准的样本中，有1个样本的esp基因和人类药物卡马西平表明存在人类源粪便污染。在一个样本中检测到通常与牛源相关且具有潜在人类健康意义的大肠杆菌rfbO157和stx2c基因，而未检测到受试化学物质。即使符合FIB标准，也可能存在基于化学物质和基因的粪便污染指标，而且有些指标可能与FIB不同，能够指示潜在来源。应用具有不同环境持久性和归宿的多种水质指标，可能会在粪便污染评估中产生更高的可信度，并为修复决策提供依据。
