UCI Ocean Study Blames Familiar Suspect: Runoff

Ocean swimmers near densely populated areas are more likely to get sick than those who swim off rural coastlines, a UC Irvine study has found.

The reason: The ocean off populated regions contains more germs because of the amount of untreated urban runoff discharged into the water, according to the study published in the April issue of the American Journal of Public Health.

“These potential health risks warrant greater public health surveillance, as well as greater efforts to reduce pollutants discharged onto public beaches,” the study concluded.

Researchers found that over a two-year period, surfers in Newport Beach and Huntington Beach were almost twice as likely to get sick than their counterparts in Santa Cruz County, about 400 miles north.

Surfers in both regions reported that their symptoms increased about 10% for each 2 1/2 hours in the water, the study found.

“It means the more you are exposed, the more likely to see an effect, and it gives an indication that the water quality is what’s causing it,” said Ryan H. Dwight, who conducted the study as part of his dissertation in environmental health science and policy.

The illnesses, which seldom required a hospital visit, included fever, nausea, stomach disorders, sore throats and skin infections.

Orange County surfers and coastal environmentalists said the study confirmed what they’d long known -- that spending time in the ocean can cause illness.

“There’s a whole lot of concern now that people who recreate in the water are exposed to a whole teeming soup of harmful pathogens,” said Matt McClain, communications director for the Surfrider Foundation in San Clemente.

Scott Morlan, coach of the Newport Harbor High School surf team, said the study confirmed what he had assumed to be the case when his students called in sick.

“I couldn’t pin it on the ocean, but you have your suspicions,” he said.

Urban runoff, which includes water from rainfall, landscaping, car washing and similar sources, flows through storm drains, picking up detritus including animal waste, and is channeled to the ocean.

Huntington Beach has been especially hit by beach closures triggered by poor water quality, including in the summer of 1999, when miles of shoreline were off-limits to beachgoers during the peak of tourist season.

Even though Huntington Beach’s coastline has become one of the most researched in the country, researchers still aren’t sure what caused the bacteria levels to jump five years ago, although many point the finger at urban runoff.

Dwight said his study confirmed what others had previously found:

If you swim in polluted water, you’re more likely to get sick.

A 1996 study by USC epidemiologist Robert W. Haile in Santa Monica found that people who swam near storm drains were nearly 50% more likely to contract colds and other illnesses than those who kept their distance.

The UCI study is one of the few to have studied the effects of urban runoff over time, according to the researchers.

Dr. Dean B. Baker, director of the UCI Center for Occupational and Environmental Health, who was one of the authors of the study, said in a news release that the study “suggests 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.”

Dwight said they focused on surfers because of their frequent exposure to the water, much as they would conduct an occupational health study.

He chose two contrasting areas, both popular with surfers: relatively rural Santa Cruz County, with a population of 255,000, and Orange County, with a population of 2.8 million and the coastal recipient of urban runoff from the three largest rivers in Southern California -- the Santa Ana, San Gabriel and Los Angeles.

Although the Los Angeles River empties into the ocean at Long Beach, Dwight said that the breakwater and current deliver the payload south into Orange County waters.

In April 1998 and April 1999, researchers asked surfers at the selected beaches how often they were sick during the previous three months and to describe their symptoms. Water quality is worst during the spring because of increased rain.

They found that in the especially rainy El Nino year of 1998, when water quality at Orange County beaches was much worse, surfers there reported twice as many symptoms as did those in Santa Cruz.

The next year, when there was more rainfall and runoff in Santa Cruz, the number of illnesses among surfers in the two regions were proportionately about the same, indicating to researchers that, unit for unit, the Orange County runoff was more polluted.

Dwight, a surfer himself, said he stays out of the ocean during the rainy season when the increased runoff brings the worst water quality.

“I have to adjust my recreation because I know what’s going on,” he said.

Roger von Butow, 58, of the Clean Water Now Coalition in Laguna Beach, has surfed most of his life and said surfers know to stay out of the water after a storm “if they have a brain.”

“It’s tough,” he said. “You’re looking at big waves but also at possible illness.”