With all the news reports—about everything from shark activity to “flesh-eating” bacteria—the ocean is getting a lot of nasty press this summer. But actually, it may be the sand that’s the ickier part of the beach, according to a new study in the journal Environmental Science & Technology. It harbors far more fecal bacteria (yes, that means poop) than the water.
“Beach goers should be aware of the health implications of contaminated beach sand, and should not assume that sand is always safe,” lead researcher Tao Yan, PhD, explained to Health.
It turns out that previous studies have shown that the sand is actually grosser compared to the water; it often has 10 to 100 times the fecal bacteria than the water, the study authors note.
For the most recent investigation, however, Yan and his team wanted to understand why.
In a lab, the researchers created a set up of three “microcosms” using samples from three Hawaii beaches, including sand and seawater normally found in those places, and then contaminated them with fecal bacteria commonly found on beaches. They then watched the samples to see how the bacteria populations changed over time. Ultimately they found that the decay process of harmful bacteria was much slower in the beach sand than in the water, which might explain why sand seems to be more of a hotbed.
But can this bacteria really hurt you? A 2012 study in the journal Epidemiology suggests that yep, it’s possible dirty sand can make you sick. The researchers analyzed sand samples from two beaches (one in Alaska and one in Rhode Island) within two miles of waste-water treatment facilities. Then, they surveyed nearly 5,000 visitors to those beaches, and found that those who played in the sand or got buried in the sand were more likely to develop diarrhea, nausea, vomiting, or other GI upset in the weeks after their visit.
Still, researchers insist their findings are no reason to quit the beach all together—just take the obvious precautions.
“The symptoms we observed are usually mild and should not deter people from enjoying the beach, but they should consider washing their hands or using a hand sanitizer after playing in the sand or water,” senior author Timothy Wade, PhD, said in a U.S. Environmental Protection Agency press release.
Also, rinsing off in the public access showers ASAP, and following that with a good shower at home after a day at the beach might not be a bad idea either. Just sayin’.
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