The 131st Annual Meeting (November 15-19, 2003) of APHA

Abstract #56279

Timothy J. Wade, PhD, MPH¹, Nitika Pai, MD, MPH², Joseph NS Eisenberg, PhD MPH², and Jack Colford, MD, PhD³. (1) UC Berkeley School of Public Health, 1918 University Ave. Suite 3B, Berkeley CA, CA 94704, 510 643 0252, tjwade@cal.berkeley.edu, (2) Epidemiology, UC Berkeley School of Public Health, 140 Warren Hall, Berkeley, CA, CA 94720, (3) Division of Public Health Biology & Epidemiology, University of California, Berkeley School of Public Health, 140 Warren Hall, Berkeley, CA 94720

Despite numerous epidemiologic studies, there remains uncertainty about how water quality indicators can best be used in the regulation of recreational water environments. We conducted a systematic review and a meta analysis of this topic with the goal of quantifying the association between specific microbial indicators of recreational water quality and gastrointestinal (GI) illness. A secondary goal was to evaluate the potential for health effects at or below the current suggested regulatory standards for indicator organism levels. We screened 976 potentially relevant studies and from these identified 27 studies. Using these data we determined summary relative risks for GI illness in relation to levels of specific indicators of water quality. Our results support the use of E. coli and enterococci in marine water at the guideline levels proposed by the USEPA. In fresh water, E. coli was a more consistent predictor of GI illness than enterococci and other bacterial indicators of water quality. Indicators of viral contamination were strong predictors of GI illness in both fresh and marine environments. Our analysis of the sources of variability found that studies that used a non-swimming control group; studies that focused on children; and studies of athletic or other recreational events resulted in elevated relative risks. Future studies should focus on differentiating the health effects related to human versus non-human sources of contamination, and to better estimate the risks of recreational water exposure among children, the immunocompromised and other susceptible persons.

Learning Objectives:

• Identify and describe study designs used to study health effects associated with recreational water
• Decribe and discuss the use of systematic reviews and meta analysis in the review of existing literature
• Discuss and evaluate the acceptability of USEPA recreational quality regulations

Keywords: Water Quality, Regulations

Presenting author's disclosure statement:
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.