Health Effects of Exposure to Microbiological Contaminants in Recreational Sea Waters of Puerto Rico

EPA Grant Number: F07D81096
Title: Health Effects of Exposure to Microbiological Contaminants in Recreational Sea Waters of Puerto Rico
Investigators: Cordero, Lyzbeth
Institution: University of Puerto Rico - Medical Sciences Campus
EPA Project Officer: Zambrana, Jose
Project Period: September 1, 2007 through September 1, 2010
RFA: GRO Fellowships for Graduate Environmental Study (2007) RFA Text |  Recipients Lists
Research Category: Academic Fellowships , Health Effects , Fellowship - Environmental Health


This study tests whether the incidence of gastrointestinal (GI) disease in bathers in recreational marine waters of Puerto Rico is associated with exposure to microbiological contaminants, and what is the increased risk associated with poor microbiological quality of sea waters. Throat, eye, skin and ear infections of bathers are also studied. The study applies an Environmental Protection Agency (EPA) questionnaire previously used in temperate bathing waters to a tropical environment.

The specific aims are to describe the population of bathers in recreational marine waters of Puerto Rico; measure densities of water quality indicators such as fecal coliforms and enterococci in coastal bathing areas in collaboration with the Puerto Rico Environmental Quality Board; control for non-water related risk factors and confounders for the illness studied; collect information about GI and other diseases for bathers and non-bathers; evaluate dose-response relationships between GI disease and bathing water quality; and estimate the incidence rates of throat, eye, skin and ear infections among bathers and non-bathers.


This is a prospective cohort study of bathers in coastal waters of Puerto Rico, to quantify the risk of morbidity in beach bathers exposed to fecal bacteria. It determines densities of microbial indicators in water where and when the study sample is selected. It is performed in two parts: a survey using a validated questionnaire completed on the beach, and a follow up telephone interview (both adapted from the EPA Questionnaire for the National Epidemiological and Environmental Assessment of Recreational Water Study, 2004). The study is designed to control for confounding factors such as long term conditions (GI problems, respiratory diseases or allergies, ear and skin problems), symptoms suffered during the week before the interview, food consumption, protective clothing or equipment, use of insect repellant, use of sunscreen, and water related activities while at the beach. Study subjects are recruited from three bathing beaches sufficiently distant from each other so that possible site-specific differences in the risk of bathing associated illnesses can be assessed. Non bathers present at the beach are included in the study. The recruited sample should include 2116 subjects. The study will abide by all Human Subjects guidelines applicable.

Expected Results:

It is expected that we will be able to discard the null hypothesis, so that we will find that the incidence of GI disease in bathers exposed to higher densities of microbiological contaminants in recreational marine waters of Puerto Rico is greater than in those less exposed. This prospective study will also help an international effort to develop a protocol for epidemiological investigations in recreational bathing waters and to determine the applicability of the World Health Organization Guidelines for Safe Recreational Water Environments to the tropical waters and conditions of the Caribbean. Its results will help in the protection of public health and to provide a framework for local decision making based in health risks encountered by bathers.

Supplemental Keywords:

gastrointestinal disease, recreational marine waters, microbiological contaminants, bathers, cohort study, fecal coliforms, enterococci, tropical waters, Caribbean, protocol,, RFA, Scientific Discipline, Water, POLLUTANTS/TOXICS, Health Risk Assessment, Recreational Water, Microorganisms, recreational water monitoring, risk assessment, bacteria, recreational beaches, interstitial zones, swimming-associated gastroenteritis, aquatic environments, fecal coliform, water quality, enterococci

Progress and Final Reports:

  • 2008
  • 2009
  • Final