Even after Florence passes, the hazards from the hurricane won't be over: Lingering floodwaters can pose a potential risk to anyone exposed to them.

"The water is not going to be safe, both from chemical and biological contamination. After a disaster, we tend to see a lot of skin infections and skin rashes," said Jeff Schlegelmilch, deputy director of the National Center for Disaster Preparedness at Columbia University.

There can also be waterborne illnesses, ranging from inconvenient but fairly harmless gastrointestinal ones, such as norovirus, to rarer, more serious bacteria, such as vibrio, a potentially deadly micro-organism.

And while North Carolina is susceptible to all of these usual threats that breed in waters left behind by a major storm, the state is also vulnerable to an additional unique — and unpleasant — set of problems.

As a top producer of hogs, North Carolina faces the distinct possibility of getting inundated with nasty pollutants through hog feces that overflow into Florence's floodwaters.

"Those waste materials are going to contain antibiotics, of which hogs are fed very high quantities to speed up their growth rate, in addition to the viruses and bacteria that are naturally found in hog feces," said Rachel Noble, a professor at the Institute of Marine Sciences of the University of North Carolina at Chapel Hill.

Among other things, hog feces can carry campylobacter or salmonella, Noble said — bacteria that if ingested, can cause diarrhea, fever and abdominal cramps, according to the Centers for Disease Control and Prevention.

It wouldn't be the first time hogs contributed to flooding woes in North Carolina. In 1999, when Hurricane Floyd slammed into the area, the carcasses of thousands of hogs and other livestock floated through toxic floodwaters that were also laced with feces, pesticide and fertilizer. The stench of the sludge was so overpowering, rescue workers had to put Vick's Vapo-Rub under their nostrils to try to numb their sense of smell as they waded through floodwaters, according to The Associated Press.

The state also has more than two dozen coal-ash pits run by Duke Energy, North Carolina's main electricity provider. The ash, a byproduct of coal burned to generate electricity, contains mercury, arsenic and lead. Duke Energy spokesman Bill Norton told the AP earlier in the week that crews would be monitoring water levels at coal-ash pits throughout the storm to try to prevent overflow.

"I think it's safe to say if there's standing floodwater, and you're back in the neighborhood, it's not clean."

There are ways for residents to prevent getting sick. Tap water typically gets contaminated by sewage treatment systems and flooding of septic systems, destroying their ability to filter out animal or human fecal pathogens; before drinking water or using it to brush teeth, boil it first. (Local and state health officials may have additional requirements depending on the contaminant.)

As for floodwaters, it's important to not let any seep into open wounds — something that can be tricky for people who are escaping a hurricane's wrath.

"Have skin protection if you're in the water," Schlegelmilch said. "Use gloves wherever you can. If you have any kinds of cuts or nicks on your leg, make sure to keep those areas very clean, and just try to avoid exposure to any of it as much as possible."

Those exposed to floodwaters should be particularly vigilant for any signs of vibrio — which is very rare, but can quickly become life-threatening. The bacteria, which is more often associated with consuming raw or undercooked oysters, can cause diarrhea and fever and skin infection, and can enter through an open cut or sore.

"If they have a really red, angry infection that makes them feel really, really bad, you have a situation where they need to seek medical help as quickly as possible," Noble said.

Don't assume water is safe to drink

The CDC offers additional recommendations for how to stay safe in floodwaters after a disaster.

Donna Knutson, deputy director for the national center for environmental health with the CDC, warned that bacteria that cause diarrheal illnesses, in the form of salmonella and E. coli, are likely to be present in floodwaters after the storm. She cautioned people who rely on well water not to assume that their water is safe to drink once they return home after Florence.

"Even if your wells don't look like they've been contaminated, talk to your local officials about testing the water after the hurricane is gone," she said.

What's most important for people returning to flooded areas, according to experts, is to not assume that water left over from the storm is OK to consume or wade through without protection, even if days have passed.

"I think it's safe to say if there's standing floodwater, and you're back in the neighborhood, it's not clean," Schlegelmilch said.