Haack Sheridan K, Fogarty Lisa R, Wright Christopher
U.S. Geological Survey, 6520 Mercantile Way, Suite 5, Lansing, Michigan, 48911, USA.
Environ Sci Technol. 2003 Aug 1;37(15):3275-82. doi: 10.1021/es021062n.
This study quantified Escherichia coli (EC) and enterococci (ENT) in beach waters and dominant source materials, correlated these with ambient conditions, and determined selected EC genotypes and ENT phenotypes. Bathing-water ENT criteria were exceeded more frequently than EC criteria, providing conflicting interpretations of water quality. Dominant sources of EC and ENT were bird feces (10(8)/d/bird), storm drains (10(7)/d), and river water (10(11)/d); beach sands, shallow groundwater and detritus were additional sources. Beach-water EC genotypes and ENT phenotypes formed clusters with those from all source types, reflecting diffuse inputs. Some ENT isolates had phenotypes similar to those of human pathogens and/or exhibited high-level resistance to human-use antibiotics. EC and ENT concentrations were influenced by collection time and wind direction. There was a 48-72-h lag between rainfall and elevated EC concentrations at three southern shoreline beaches, but no such lag at western and eastern shoreline beaches, reflecting the influence of beach orientation with respect to cyclic (3-5 d) summer weather patterns. In addition to local contamination sources and processes, conceptual or predictive models of Great Lakes beach water quality should consider regional weather patterns, lake hydrodynamics, and the influence of monitoring method variables (time of day, frequency).
本研究对海滩水域及主要源材料中的大肠杆菌（EC）和肠球菌（ENT）进行了量化，将其与环境条件相关联，并确定了选定的EC基因型和ENT表型。与EC标准相比，游泳水ENT标准被超过的频率更高，这对水质产生了相互矛盾的解释。EC和ENT的主要来源是鸟类粪便（每只鸟每天10⁸个）、雨水排放口（每天10⁷个）和河水（每天10¹¹个）；海滩沙子、浅层地下水和碎屑也是额外的来源。海滩水EC基因型和ENT表型与所有源类型的基因型和表型形成聚类，反映了分散的输入。一些ENT分离株的表型与人类病原体相似和/或对人类使用的抗生素表现出高水平抗性。EC和ENT浓度受采集时间和风向影响。在南部海岸线的三个海滩，降雨与EC浓度升高之间存在48 - 72小时的滞后，但在西部和东部海岸线海滩则不存在这种滞后，这反映了海滩朝向对夏季周期性（3 - 5天）天气模式的影响。除了当地污染源和过程外，五大湖海滩水质的概念模型或预测模型应考虑区域天气模式、湖泊水动力以及监测方法变量（一天中的时间、频率）的影响。
