Hurricane Irene's powerful one-two punch of high winds and heavy rainfall will undoubtedly result in dangerous airborne debris, fallen trees and flash floods.
But after her winds die down and her storm surges recede, a "whole suite of issues that may not have been considered" will remain, said Ronald Kendall, director of The Institute of Environment and Human Health at Texas Tech University.
Victims of Hurricanes Katrina, Rita and Ike know all too well that the lingering risks of contaminated water, toxic mold, weakened structures and infectious diseases can prove harmful over the days, weeks, and even months after the hurricane winds have passed. But this dangerous reality may not be on the radar of people along Hurricane Irene's unusual path.
While people all the way up the Eastern Seaboard probably heard the staggering numbers of deaths and injuries directly related to these earlier disasters, "some of the more subtle effects may not have stayed in the news for people outside the immediate area," said Kim Knowlton, a senior scientist with the Natural Resources Defense Council.
One of these potentially unrecognized risks is what Patrick Breysse of Johns Hopkins Bloomberg School of Public Health calls the "soupy mess," which is likely to flow down the streets in heavy populated areas. And dodging the risk of drowning in it may not be enough to stay safe.
Floodwaters can be contaminated by a wide array of toxins and pathogens in metropolitan areas, Breysse told HuffPost. Chemicals from cars, machinery, gas stations, dry cleaners, toxic waste dumps and oil distributors are just some of its likely ingredients. Pesticides, solvents and other household products stored in flooded basements and garages may also find their way into the mix.
"There are a lot of toxic substances that may be stored appropriately -- until there is flooding," said Knowlton. "The risk could be substantial."
What's more, Kendall's research has found that floodwaters can churn up sediments carrying arsenic, polycyclic aromatic hydrocarbons (PAHs) and neurotoxic lead -- which can later be redeposited in backyards and playgrounds.
Then, of course, there is the notorious sewage problem. In older cities like New York and Boston, combined sewage and stormwater systems often get overloaded -- even after just moderate amounts of rainfall.
"Storm surges can overflow and shut down treatment plants," said Breysse, noting that a big sewage treatment plant sits near the Chesapeake Bay, threatening Baltimore.
Add to this the hurricane-induced risks of flooded wells and pressure losses from lost electrical power, and there is good reason that residents have been advised to stock up on bottled water.
But drinking the dirty water isn't the only problem. Kids that play in streets full of standing water can run the risk of contracting a skin rash or water-borne illness from microbial agents -- the same reason you shouldn’t go to the beach after it rains.
Depending on what is in the water, chemicals can also penetrate through the skin and increase a person's future risk of cancer, added Breysse.
"Given the uncertainty about what’s in the water, it is prudent to avoid contact," he said.
Indoor water hazards can be even worse. Indoor flooding or water intrusion due to roof damage can quickly lead to the growth of mold within spaces where people live and work.
Molds are known to cause respiratory problems, particularly for people with asthma. New York City, which falls in Irene's path, has especially high rates of childhood asthma -- up to 12 times the national average in some neighborhoods.
"This was one of the big problems that occurred in post-Katrina," Kendall said. "It can be very deadly to people that are allergic."
"Children with asthma should not be exposed to mold," added Maureen Lichtveld, who is currently studying the link between mold resulting from Hurricane Katrina's floodwaters and childhood asthma.
Lichtveld, chair of environmental policy at Tulane University School of Public Health and Tropical Medicine in New Orleans, recommended either hiring a professional or cleaning up any spots of mold with a chlorine solution yourself. But beware that mold isn't always visible, she added. It is known to grow between walls.
The confounding effects of wind and water increases other health hazards as well. If storm winds blow screens off of windows or doors, and take down electrical supplies, Hurricane Irene may be a "recipe for mosquitoes," said Knowlton.
Outbreaks of disease could also result if people are stuck in shelters over a long period of time without adequate sanitation. As Brysse noted, this became a major problem for New Orleans.
"Still, safety is first and foremost," said Breysse. "Even after the fact, there are going to be structural concerns with housing. People need to be careful."
This could be all the more important with Irene. Infrastructure along the Mid-Atlantic and New England coastline is less well designed to withstand a hurricane than around veteran hurricane cities.
There's perhaps at least one health hazard that East Coasters don't have to worry too much about: ozone pollution. With fewer cars and air conditioners running, these levels could drop.
Breysse referred back to the Atlanta Olympics, when a ban on driving improved the air "noticeably." Still, he warns that the inhalation of mold particles could become a concern over time.
"We've learned from past major storms," said Kendall. "But as time goes by, we lower our guard."
Kendall recently visited both New Orleans and Galveston, and noted the devastation that remains from both Katrina and Ike, including boarded up homes and mold infestations.
"It's not like the flood waters just come and go, and people can go back to normal," he added. "For somewhere like New York City, this is uncharted territory. This storm is as big as the state of Texas."