UCI graduate and professor examine water quality in northern Orange County. One says viruses, not bacteria, should be tracked.
Two new studies point to urban runoff as the delivery system for bacteria and viruses that make swimmers sick in northern Orange County.
A paper by a UC Irvine graduate, just published in the American Journal of Public Health, says that urban runoff sickened surfers using Newport and Huntington beaches nearly twice as often as those surfing in rural Santa Cruz County during the winter of 1998.
Another study by a UC Irvine professor, to be published later this month in the Journal of Applied Microbiology, says when looking for potential health hazards in water, the state would be better served looking for viruses rather than bacteria levels.
The studies are among a crop of recent research looking at the causes of pollution in Orange County’s coastal waters. Studies co-authored by UCI professor Stanley Grant, published online in late March by the American Chemical Society, criticized the state’s beach warning system as too slow to be effective, and on Thursday the Orange County Health Care Agency cautioned about fish contamination in Newport Bay based on preliminary results of a study still being completed by the Southern California Coastal Water Research Project.
“These findings certainly aren’t going to be a surprise to anybody who surfs in Orange County, but this is the first time it’s been quantified,” said Ryan Dwight, a 2001 UCI graduate who wrote the surfer sickness study for his PhD dissertation.
Dwight interviewed about 850 surfers about symptoms such as stomach pain, fever, cough and skin infections and correlated those with how often they were in the water during the winter in 1998 and 1999. His results showed that the more exposure to water surfers had per week, the more often they reported symptoms, he said.
Dwight used Santa Cruz County as a comparison area because it’s more rural and generally has better water quality and less runoff than Orange County. Surfers there reported fewer symptoms in both study years and reported close to half as many symptoms as Orange County surfers in 1998, when El Niño storms were blamed for spreading pollutants along the Orange County coast.
“What I think this study brings [to light] is quantified awareness of this health problem and the need to address it,” Dwight said. “Epidemiology studies need to be conducted with urban runoff.”
UCI environmental health, science and policy professor Sunny Jiang studied viruses in urban rivers in Southern California and concluded that current water-quality standards may not accurately depict the amount of viruses in the water.
Water-quality resources would be better spent searching for the sources of viruses in the water than looking for bacterial contamination, Jiang said.
“I feel like if we are spending millions of dollars treating indicator bacteria, which may be coming from multiple different sources including soil, we are spending money in the wrong place,” she said. “We could miss the target we’re looking for, which is preventing human diseases.”
Her study also notes that urban runoff, which carries viruses into coastal waters, should be managed better during storms to prevent illness.
Runoff from urban areas, which can carry nutrients from fertilizers and other chemicals, has often been targeted as the culprit in coastal pollution.
“That’s why we’re diverting 2 1/2 million gallons a day off the beach [into the sewer system], to try and minimize the impact of those discharges,” said Ken Theisen, an environmental scientist with the Santa Ana Regional Water Quality Control Board.
The water board is trying to stop runoff wherever it can, and other agencies also are working on the issue, he said.
Dwight’s study probably overestimates pollution levels in northern Orange County, but it is in the ballpark, Theisen said.
Solving runoff problems can be costly. Theisen estimates a $250,000 price tag per storm drain to control runoff, divert it to sewer systems, create a wetland treatment system or install filters.
