Floodwaters from Hurricane Harvey soaked up billions of bacteria that could pose a lingering threat to Texans affected by the storm.
A new analysis of the water organized by the New York Times found that at least two Houston neighborhoods showed levels of bacteria hundreds of times above normal – and even contained the fecal microbe E. coli.
In the living room of one home that was filled with murky brown water, researchers found levels of E. coli that were 135 times what’s considered safe, the Times reported. In that home’s kitchen, they found elevated levels of arsenic and lead.
The heightened numbers are no surprise to Rachel Noble, a professor of marine biology at the University of North Carolina at Chapel Hill. As floodwaters bubble past city streets and inundate cars and homes, they collect sharp objects, sweep up insects and wildlife, and gather human waste, Noble told Business Insider.
“As long as people are not eating and drinking items that have been in floodwater and they are following any boil advisories for municipal water sources, they should be okay with washing hands and regular hygiene,” she said.
There is one type of bacteria in the water that concerns Noble, however: Vibrio.
Unlike fecal bacteria that make you sick only when ingested, Vibrio bacteria pose a rare but potentially deadly risk to anyone with an open wound. In the wake of Hurricane Katrina, five people died and 22 lost limbs as a result of Vibrio infections. The microbes thrive in the open ocean, but storms and floods sweep them into urban areas where they can pose unforeseen risks to people.
“For Vibrio, open wounds and scrapes are a major concern. If people with those are exposed to floodwaters and things that came in contact with flood waters, they need to be vigilant about red infection wounds with cellulitis, they need to be seen, and they need to NOT sleep on the wounds,” said Noble. “These things can progress over a 10 hour period to a point of no return requiring amputation.”
Noble said that anyone in direct contact with floodwater and who is experiencing infection-like symptoms should keep a close eye on themselves. She advises paying close attention to any open wounds and looking out for those that get “hot and angry,” or red and raised. Symptoms like fever and chills can also be a warning sign for Vibrio infection, she said.
Other floodwater contamination risks include industrial chemicals and solvents, as well as tetanus, an infection caused by bacteria in soil, dust, and manure that can enter the body via a cut or puncture wound.
Richard Bradley, the chief of emergency medical services and disaster medicine at the University of Texas’ McGovern Medical School, told Time that because the bacterial count in floodwater gets so high, the chance of getting a skin infection is serious.
“Floodwater mixes with everything below it,” he said. “If it covers a field with pesticides, it picks up the pesticides. It can also carry animal waste from fields and forests.”
Yet another problem in flooded areas is unexpected wildlife, since snakes, insects, and other wild animals can be drawn to the water or swept up in it.
“Storm activity definitely increases the potential for snakebite as the snakes get flooded out and seek higher ground,” Bryan Fry, an expert on venomous snakes at the University of Queensland in Australia, told The Washington Post.
Other dangers persist even after floodwaters recede, since wet environments in houses and buildings are ideal for mold. In the wake of Hurricane Katrina in 2005, close to half of all inspected homes had visible mold, according to the CDC. Mosquitoes and other pests are also attracted to standing water.
Regardless of where you are, the ways to keep yourself safe are the same: ensure you’ve gotten your vaccinations, wash your hands frequently, and let your doctor know if you have any cuts or open wounds that have come into contact with potentially dangerous water.