Urban runoff poses increased health threat for surfers, other beach users, UCI study shows


Findings suggest current pollution guidelines may not be sufficient

Irvine, Calif., April 5, 2004 -- Surfing the beaches south of Los Angeles can make you sick to your stomach … literally. According to a UC Irvine study of hundreds of surfers, urban beach water made surfers ill twice as often as did ocean surf in more rural areas. The findings suggest that widespread exposure to urban runoff at beaches in highly populated areas increases health risks to all swimmers, even when pollution levels are within current environmental monitoring guidelines.

The researchers compared rates of reported health symptoms among California surfers in urban north Orange County and rural Santa Cruz County during the winters of 1998 and 1999. The urban surfers reported almost twice as many symptoms as the rural surfers in the rainy El Niño winter of 1998. During both study years, reported symptoms for both groups increased by about 10 percent for each 2.5 hours of weekly water exposure. These symptoms ranged from fever, nausea, stomach pain and diarrhea to sore throat, eye redness and skin infection This study is one of the first to quantify the health effects of ocean water by monitoring beach users from both urban and rural areas. It was led by Ryan H. Dwight of the UCI Environmental Health Science and Policy Program and Dr. Dean Baker, professor of medicine and director of the UCI Center for Occupational and Environmental Health. Study results appear in the April edition of the American Journal of Public Health.

North Orange County – which includes America's "Surf City," Huntington Beach, and the popular vacation destination, Newport Beach – was designated as the urban site because its watershed is in one of the most developed areas in the world and generates highly polluted runoff, which discharges primarily through the Santa Ana River. Santa Cruz County was selected as the rural site because of its cleaner coastal water quality and watershed characteristics. Both are highly popular surfing locales.

"Surfers are an excellent group to study, because they are in the water almost every day and are exposed to more bacterial pathogens from runoff than casual beach users," said Dwight, himself an avid surfer. "These potential health risks warrant greater public health surveillance, as well as greater efforts to reduce pollutants discharged on public beaches."

According to Baker, this study differs from others because it looked into the health impacts of general exposure to beach water, not to specific sites where pollutants released by sources such as industrial plants or wastewater treatment plants can be monitored. "Because our study looked at the health effects associated with open beaches, it suggests that the current guidelines to monitor and close beaches in urban areas such as Orange County may not be sufficient to protect the public's health from general water runoff," Baker said. Betty H. Olson of UCI and Jan C. Semenza of Portland State University collaborated on the study, which was supported by the University of California Toxic Substances Research and Teaching Program.

Source: Eurekalert & others

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
    Published on PsychCentral.com. All rights reserved.