How Often Do Surfers Get Sick from the Water? Study Says…

Cajoled with a free bar of wax and surf forecast subscription, more than 600 Southern California surfers helped quantify water-borne illness.


Rain swept through Southern California yesterday, and if you’re a surfer you know that you should probably stay out of the water today, as storms wash all matter of contaminants into our mother ocean. We know that rains flush E. coli and Enterococcus into our favorite playground—but just how bad is it? A recent study by a coalition led by UC Berkeley attempts for the first time just how likely you are to end up with something nasty in the stomach if you paddle out post-storm.

More than 650 San Diego area surfers agreed to download a smartphone app and record all their surf sessions, as well as any illness they experienced, in exchange for a free bar of wax, a subscription to a forecast service, and the furthering of knowledge for the human species. The study was conducted during SoCal’s rainy season, such as it is these days, in the winters of 2013-14 and 2014-15.

“Much of Southern California’s beach water quality during the dry, non-rainy portions of the year is quite good,” the study reports. “Bacteria contamination levels, for the most part, remain well under the water quality standards that state and federal regulators have set to protect human health. However, when rain storms wash pollution off the land and send it through storm drains to the coastal zone, public health officials routinely issue countywide advisories urging beachgoers to not enter the water because of concerns about microbial contamination. Southern California simply does not possess the infrastructure to store and treat large volumes of stormwater runoff prior to its discharge at the beach. It also is unclear if building this infrastructure – estimated to cost many billions of dollars – would be the most effective solution because state and federal beach water quality standards for health risk are based on scientific studies conducted exclusively during dry conditions in the summer.”

Winter’s a different deal. One of the major issues facing Southern Californians is that the long intervals between rain storms allow more gunk to build up, which is then all washed down at once.

The study measured how often surfers went out (on average, twice a week for two hours), whether they submerged their heads (96 percent did), and whether they got sick if they had a session within 72 hours of a rain event. The results? Surfers suffered gastrointestinal illness about 30 times out of 1,000 during a “wet” session (after a rain) and 25 out of a 1,000 during a “dry” session. Put another way, there’s a 2.5 percent chance of getting sick on a normal day and a 3 percent chance after a storm.

“While state and federal regulations focus largely on GI illness, the Surfer Health Study also examined illness rates for six non-GI symptoms – skin rashes, open wound infections,
earache/infections, sinus pain/infections, fever, and upper respiratory infections. Nearly all of the illness rates for these symptoms increased when surfers entered the ocean compared to when they didn’t go in the ocean, although not all of these symptoms can be directly related to water quality impairments. Cumulatively, across all infectious symptoms, there was an excess risk of 19 surfers per 1,000 on average who became ill when they entered the ocean in wet weather, compared to when they did not enter the ocean,” the study said.

The takeaway? Regular old sessions aren’t that much better than post-storm ones. The water might meet state and federal guidelines, but there’s still too much crap in it.

Photo by Daniel Hoherd

Showing 4 comments
  • scott sterbenz
    Reply

    interesting article.

    fwiw, I swim in SFBay every day rain or shine.

    no waterborne illnesses yet or that I’ve heard of at the south end rowing club.

  • Len
    Reply

    The study does not tell us if surfers are getting sick from the ocean at all really because I don’t see a control group of people who didn’t go in the ocean charting if they got sick. The difference in illness rates between post rain and dry day surfing is small and could have occurred by chance alone. If you figure a 2.5 percent chance of getting gi illness per week and there is 52 weeks in a year the average surfer seems to get ill about once per year. That sounds fairly infrequent and likely close to the rate in the general population.

  • JT
    Reply

    We white water kayakers have similar problems. Here in the eastern US a lot of runoff into creeks contain fecal matter from farm animals as well as chemical fertilizers that I’m sure aren’t doing us much good. There’s a ritual that if you swim via wet exit rather than roll when you flip you must drink a beer from your bootie. I carry a glass ‘boot’ shaped mug in my car for those occasions.

  • Alex
    Reply

    @len . the study itself includes “unexposed” participants (participant time ranges) which covers for people not surfing at all. Surprisingly to me, the numbers for unexposed are not much below the “dry” results which makes it sound like surfing really ain’t all that bad!

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