Prompted by air quality concerns and complaints from parents, Hampstead Elementary School has closed four portable classrooms until Monday while cleaning crews scrub walls, floors, ceilings and desks.
The school has shifted the fifth-graders into other spaces in the main school building.
An indoor air study was conducted last month by an independent research company after a problem with portables at Mount Airy Middle School last fall prompted a countywide inspection of that type of classroom. The study detected "elevated levels" of carbon dioxide and fungus in the four Hampstead portable classrooms, according to results released to school officials March 31.
Hampstead Principal Theresa Ball said two pupils in the portables frequently visited the school's health room complaining of nausea and headaches.
Ball said she sent letters with the results of the inspection to parents this month, but they complained that the message was not specific about when the problem would be remedied.
"The letter listed the problems and how to remedy them, but there was no timetable when the solutions would be put into action," said Alisae Ostendorf, mother of a 10-year-old daughter who has been complaining of chronic nausea.
"A side effect of the elevated levels is nausea," she said. "The letter got parents riled up, and it just snowballed."
Parent Leo Korotki said, "Basically, they said they would do something, but they didn't know when." His 10-year-old son has had nausea and fatigue for several months.
"Something is going on, and it should be fixed immediately," Korotki said.
His wife, Robin Korotki, volunteers in her son's portable classroom and usually comes home with a headache, he said.
"They got abnormal test results and should have done something right away," said Korotki, a physician. "Is it deadly? No. Can it cause problems? Yes."
The two probable sources of the fungus are carpeting and the ventilation system, according to the report.
To remedy the situation, the county will clean the carpet and examine the heating and air-conditioning systems to ensure there is adequate intake of outside air. When the school closes for the summer, maintenance workers will probably replace the carpet with some type of tile, officials said.
"We are working through the weekend to sanitize the carpet, walls and furniture," Ball said.
Ray Prokop, the school system's facilities director, said schools across the country are experiencing similar problems with portables.
"These things are made as inexpensively as possible," Prokop said. "We can't do anything about the original construction, but we can address installation and maintenance. We are dealing with the causes."
Mount Airy Middle School faced air-quality problems with several portables last fall when moldy carpets, water-damaged windowsills and a musty odor sickened teachers and children.
"The situation in Hampstead is vastly different," said Prokop, attributing the elementary school's problems to recent heavy rain. "The levels at Hampstead are not anywhere near what we had at Mount Airy."
Hampstead Elementary's portables will be retested for carbon dioxide levels Monday.
"I won't be comfortable with my daughter going back into the portable if levels are still high," Ostendorf said. "Portables are supposed to be a short-term fix, but we are using them as a permanent fix."