Here’s What a Microbiologist Wants You to Know About RFK Jr.’s Creek Swim

When the temps heat up, there’s nothing better than a refreshing swim to cool off—but if the water you’re wading in isn’t exactly up to snuff, the experience can turn way less chill. And earlier this week, the top public health official in the US reminded us all of that.

Over the weekend, Robert F. Kennedy, Jr., the head of the US Department of Health and Human Services, went viral for taking a dip in Rock Creek, a notoriously sewage-saturated channel that runs through Washington, DC’s Dumbarton Oaks Park. In a Mother’s Day post on the social media platform X (formerly known as Twitter), Kennedy shared photos of himself hanging out in the water (in what appeared to be jeans, no less), accompanied by two of his grandchildren as well as other family members. The pics sparked a lot of…thoughts, so we decided to do a deep dive (sorry) into why this activity could be a legit health risk—in case the words “sewage-saturated” didn’t already clue you in.

Some important background: Thanks to issues like trash accumulation, polluted runoff, and, yes, “sewage overflows,” Rock Creek is known for “high levels of bacteria and other infectious pathogens that make swimming, wading, and other contact with the water a hazard to human (and pet) health,” according to the National Park Service. One example is E. coli bacteria, which also serves as a telltale sign of contamination with fecal matter (a.k.a. poop), Bill Sullivan, PhD, a microbiologist and professor at the Indiana University School of Medicine, tells SELF. “If there is animal feces or agricultural waste in proximity to the waterway, storms or rain can push that contaminated soil into the water,” he says. Besides E. coli, other potentially present pathogens include Salmonella; viruses like rotavirus, norovirus, and hepatitis A; and parasites like Cryptosporidium, Giardia, and Toxoplasma gondii, according to Dr. Sullivan. What’s more, the water doesn’t have to look visibly dirty (or feel different on your skin) to contain any of the above, so you can’t know if you’re in the clear just by eyeballing it.

Coming into contact with these bugs isn’t only nasty, it can also be dangerous, since they can make you seriously sick. Think of entering Rock Creek (or a similarly dirty body of water, like Paris’s River Seine, a venue for the 2024 Olympic open swimming events despite widespread controversy over its safety) as an “aquatic Russian roulette,” Dr. Sullivan says. “When you’re dealing with these fecal-contaminated waters, you might get lucky on one day, but you might not get lucky the next day, so it’s just not worth the risk.” If you do develop an infection, you can expect symptoms of stomach distress like cramps, nausea, vomiting, and diarrhea, according to Dr. Sullivan.

Besides those GI issues, Dr. Sullivan adds, you could potentially also be at risk for more serious side effects, like severe dehydration (if the diarrhea or vomiting is bad enough), liver failure (in the case of hepatitis A), or miscarriage or birth defects during pregnancy (in the case of Toxoplasma gondii). What’s more, older people—like Kennedy, who is 71—and young children tend to be especially vulnerable to more intense illness and complications.

Due to this laundry list of health hazards, swimming in Rock Creek and other DC waterways has actually been banned since the early 1970s, according to the DC Department of Energy and Environment—a policy specifically mentioned by the National Park Service on its Rock Creek webpage. “Please protect yourself and your pooches by staying on trails and out of the creek,” the federal agency states, adding, “This means wading, too!”

When it comes to that Mother’s Day creek swim, Dr. Sullivan’s concerns extend beyond the health risks to Kennedy as an individual—it’s “normalizing behaviors that are downright dangerous,” he says. Now, he adds, “people are going to see this post or hear about it in the news and think that it’s perfectly fine for them and their kids or maybe their dog to go play in Rock Creek,” when, in fact, the opposite is true. And like we mentioned before, the issue isn’t limited to Rock Creek (or DC) specifically, either—it’s a nationwide problem. In a 2022 analysis of data encompassing more than 1.4 million miles of rivers and streams in the US, the Environmental Integrity Project found that 51% were “too polluted to meet standards for swimming and recreation, aquatic life, fish consumption, or as drinking water sources.”

Still, after months of watching Kennedy push dubious public health policies like removing fluoride from public water supplies, Dr. Sullivan wasn’t exactly shocked when he heard about this latest controversy: “Even if RFK says that he and his grandkids were perfectly fine, they had a great day, nothing happened, no one got sick—that’s not the point,” Dr. Sullivan says. “We cannot communicate to the American public that this is a safe activity to do.” We’re all for getting outside and finding ways to cool off when you do so—just make sure it’s in a body of water that’s clean enough for it.

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