BOSTON -- Bay Staters bailing out after days of flooding were cautioned to be mindful of dangerous mold as they start cleaning out homes, businesses and basements.

NewsCenter 5's Liz Brunner reported that it takes a few days for mold to form.

"If you've got mold growing in your house in places, for a lot of people that's very unhealthy" said Harvard-trained scientist Jeffrey May, who has authored several books on mold and inspects buildings for mold problems.

May said after a house is pumped out, it's wise for residents to dry the area with heat or a good dehumidifier.

"One of the big mistakes people make is they try and ventilate the basement using air from the house. They'll have the door to the basement open and they'll have all these fans and if there's mold situation, they're actually going to be blowing all those spores all over the basement and then into the house," May said.

For major flooding, May said, residents should just cut out soaked drywall and baseboard, even if looks clean.

"If you've got drywall that's gotten really saturated, it's just got to be removed. A hundred percent of the time, in a basement anyway, it's just going to get moldy," May said.

Residents should also make sure to take all items out of the basement, drying them out and wiping down furniture, boxes and children's toys. If there are any rugs that are wet, they should be thrown out.

"I've sampled hundreds and hundreds of basement carpets for molds and I could count on two hands the number of carpets that didn't have some mold," May said.

Floors should be washed with a solution of two capfuls of bleach to each gallon of water.