Extreme Precipitation and Beach Closures in the Great Lakes Region: Evaluating Risk among the Elderly

Kathleen Bush,Cheryl Fossani,Carina Gronlund,Bhramar Mukherjee,Shi Li,Marie O'Neill

doi:10.3390/ijerph110202014

Abstract

As a result of climate change, extreme precipitation events are expected to increase in frequency and intensity. Runoff from these extreme events poses threats to water quality and human health. We investigated the impact of extreme precipitation and beach closings on the risk of gastrointestinal illness (GI)-related hospital admissions among individuals 65 and older in 12 Great Lakes cities from 2000 to 2006. Poisson regression models were fit in each city, controlling for temperature and long-term time trends. City-specific estimates were combined to form an overall regional risk estimate. Approximately 40,000 GI-related hospital admissions and over 100 beach closure days were recorded from May through September during the study period. Extreme precipitation (≥90th percentile) occurring the previous day (lag 1) is significantly associated with beach closures in 8 of the 12 cities (p < 0.05). However, no association was observed between beach closures and GI-related hospital admissions. These results support previous work linking extreme precipitation to compromised recreational water quality.

Highlights

The concentration of bacterial indicators in recreational water, such as Escherichia coli (E. coli), has been linked to cases of waterborne disease [1,2,3]
No consistent trend was observed between beach closures and gastrointestinal illness (GI)-related hospital admissions among the elderly
According to the IPCC Special Report on managing the risks of extreme events and disasters, a changing climate is linked to changes in frequency, intensity, duration, and timing of extreme events [56]

Summary

Introduction

The concentration of bacterial indicators in recreational water, such as Escherichia coli (E. coli), has been linked to cases of waterborne disease [1,2,3]. Health risks associated with exposure to contaminated recreational water include skin, eye, ear, and upper respiratory irritations and infections, as well as gastrointestinal illness (GI) [4]. The 1986 United States Environmental Protection Agency (EPA) recreational water quality criteria for freshwater beaches include a daily E. coli concentration of less than 235 colony forming units (CFUs) per 100 milliliters of water [2,3,4,5,6]. Bacteria concentrations exceeding these criteria trigger swimming advisories and/or beach closures to prevent exposure to waterborne pathogens. Recreational water quality is influenced by precipitation and other hydrometeorological parameters [9,10]

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