Every month, Ann Mason leaves town for a week or two and does her best to make a budget vacation of it.

But when she gets into the 1980s Winnebago on the appointed Friday morning with her husband, they are careful to leave on time. They usually head for a campground near Orlando, one they checked out carefully.

“I’m fleeing for my life,” Mason said, in a voice that sounds hoarse, as usual.

They leave on time because being late could trigger another severe health crisis, she says, and she isn’t sure how many more she can handle now that she is well into her 70s.

Within hours of their exits from town, she says, the very air in their ordinary Sarasota neighborhood becomes toxic to her. So much so, Mason says, that she has often had severe respiratory problems, extreme face and body swelling and terrible flu-like symptoms “three times worse than any flu you have ever had.”

Most people would see and feel no pollution problem in her quiet neighborhood on Clematis Street. It’s not near a sewage plant, incinerator, or waste dump. In fact, the toxins Mason is dodging are probably less plentiful there than in most Florida neighborhoods.