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THE NATIONAL EPIDEMIOLOGICAL AND ENVIRONMENTAL ASSESSMENT OF RECREATIONAL WATERS: RESULTS FROM THE FIRST SUMMER FULL-SCALE STUDIES
Citation:
WADE, T. J., R. L. CALDERON, E. A. SAMS, K. P. BRENNER, M. BEACH, A. H. WILLIAMS, AND A. P. DUFOUR. THE NATIONAL EPIDEMIOLOGICAL AND ENVIRONMENTAL ASSESSMENT OF RECREATIONAL WATERS: RESULTS FROM THE FIRST SUMMER FULL-SCALE STUDIES. Presented at International Society for Environmental Epidemiologists, New York, NY, August 01 - 04, 2004.
Impact/Purpose:
The objectives of this research are: (1) to evaluate rapid state-of-the-art measuement methods of pathogens that may indicate the presence of fecal pollution in recreational waters (beaches); (2) to obtain, jointly with a sister laboratory (NHEERL), a new set of water quality data and related health effects data at a variety of beaches across the U.S., in both marine and non-marine waters; (3) to analyze the research data set to evaluate the utility of the tested measurement methods, the new EMPACT monitoring protocol, and the health effects data / questionnaire, in order to establish a relationship between measured pathogens and observed health effects; and (4) to communicate the results to the Office of Water in support of their efforts to develop new state and/or federal guidelines and limits for water quality indicators of fecal contamination, so that beach managers and public health officials can alert the public about the potential health hazards before exposure to unsafe water can occur.
Description:
Introduction
The National Epidemiological and Environmental Assessment of Recreational Waters (NEEAR) is a multi-year study of recreational water conducted by the United States Environmental Protection Agency and the Centers for Disease Control and Prevention (CDC), designed to evaluate new rapid and specific indicators of recreational water quality and to determine their relationship to health effects. These studies are the first to evaluate the association between health effects and novel rapid indicators of recreational water quality.
Methods
We conducted epidemiologic studies at a Lake Michigan beach and a Lake Erie beach during the summer of 2004. Interviewers approached beach goers and solicited their enrollment in the study. Interviewers asked beach-goers to return to the interview station to complete a series questions relating to whether or not the beach-goers went in the water and what other types of activities they did on the beach as the left the beach for the day. Ten to 12 days after the beach interview, interviewers telephoned each household to ascertain health symptoms (gastrointestinal, respiratory, eye, ear, skin) experienced in the days following the beach interview.
At each beach water samples were collected at several transects (three at Lake Michigan and five at Lake Erie) at two depths, 0.3 m (shin depth) and 1 m (knee depth), three times a day. Samples were tested for enterococci using the standard method (Method 1600) and for enterococci and Bacteroides sp. using novel methods including rapid PCR and an antibody based, fiber-optics system.
Results
At the Lake Michigan Beach, we conducted surveys on 20 days between June 1 and August 3. 2834 household interviews were attempted, 1683 household interviews were completed. Data were available on 2877 individuals. At the Lake Erie beach, we conducted surveys on 13 days between August 2 and September 14. 2962 households interviews were attempted, and 1634 household interviews were completed. Data were available for 2840 individuals.
Both beaches experienced significant variability in water quality over the summer. At Lake Michigan, daily geometric means of enterococci (Method 1600) ranged from 1 to over 1000 with and 3 days exceeded the current US EPA guideline value. At Lake Erie daily geometric means of enterococci ranged from 1 to over 800 and 6 days exceeded. Gastrointestinal, ear, eye, and skin rash symptoms were significantly associated with swimming. The relationships between health symptoms and the traditional and rapid indicators will be fully evaluated and presented in detail.