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Bacterial Contamination in Long Island Sound: Using Preemptive Beach Closure to Protect Public Health
agriculture, wildlife, wastewater treatment plants, central sewer failures, private septic systems, and stormwater systems (Byappana- halli et al., 2012). Predicted increases in the frequency of heavy precipitation events and water temperature (National Oceanic and Atmospheric Administration, 2023) likely will increase the frequency and magnitude of future contamination events. The regulations and policies concerning beach closure at the federal and state level are potentially inadequate to protect public health. Current laboratory testing procedures require approximately 24–48 hr between sample collection and laboratory reporting of assay results, during which time the poten- tially contaminated beach remains open. Beaches are closed if enterococci levels are found to be above a threshold value; however, due to the long turnover time for analysis, beach closures based on previous-day bac- teria tests are accurate only 33% of the time (Morrison, 2003). Furthermore, beach water often is tested only once per week, which suggests that local health departments do not have the necessary information to determine if their beaches are contaminated on popular beach bathing days. Though the exposure-response association between bacterial indicators of fecal contami- nation in water and adverse health outcomes (e.g., gastroenteritis) among bathers has been Daryn Ramsden, MPH, PhD Yale School of Public Health Sarah Esenther, MPH Yale School of Public Health East Shore District Health Department Brandon Marks Yale College Aine Lehane, MPH Yale School of Public Health Rona Chen, MPH Yale School of Public Health Robert Dubrow, MD, PhD Yale School of Public Health Yale Center on Climate Change and Health Michael A. Pascucilla, MPH, REHS, DAAS Yale School of Public Health East Shore District Health Department
'786&(8 Public health ocials conduct water quality monitor- ing at marine beaches to reduce the risk of gastrointestinal illness. Climate change causes increased frequency of heavy rainfall events associated with pathogen-laden runo, necessitating review of beach closure policies to ensure they are adequate to protect public health. Specifically, the lag of approximately 24–48 hr between collecting the water sample and report- ing of assay results represents a period when the potentially contaminated beach remains open. Preemptive beach closure—the shutdown of beaches following a rainfall event of predetermined size—could serve as a solution. We surveyed 15 health departments of Connecticut towns along Long Island Sound and found that only 3 sampled after heavy rainfall events and only 6 practiced preemptive beach closure. We then used historical meteorological and water sampling data in logistic models to develop rainfall thresholds for preemptive closure for four Connecticut coastal towns and identified 2-day precipitation as the primary predictor of enterococci levels. Because preemptive beach closures can cause daily life and economic disruptions and are not widely popular, we engaged with stakeholders, town ocials, and the public at each stage of the project. Through collaboration and transparency with communities, preemptive beach closure policies were implemented in two towns.
Introduction U.S. public health ocials at state and local levels are responsible for conducting water quality monitoring at marine beaches. It is evident that our changing climate and other human impacts necessitate review and revi- sion of beach closure policies to reduce the risk of gastrointestinal illness in communities with recreational water activities. Alterations related to climate change in weather patterns have led to increased con-
tamination of marine waters (Heaney et al., 2014; Shehane et al., 2005). Transport and growth of enterococci—a fecal indicator bac- teria distinguished by its ability to grow well in high salinity environments—is enhanced by heavy rainfall events that increase microbe- laden runo and results in the release of fecal material into watersheds and eventually water bodies including coastal waters (She- hane et al., 2005). Sources of this potential contamination and runo include animal
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