Mount Airy Elementary School will be expelling millions of bacteria, school officials say, when contractors rip out the carpet in the first- and second-grade section of the building.
And just so the microorganisms don't try to re-enroll, a less hospitable tile floor will replace the carpet by the time students return in September, said Vernon Smith, director of support services for the Carroll County school system.
Test results last week showed that carpet in at least four classrooms on the ground floor is a breeding ground for bacteria suspected of causing some children and a teacher to have chronic headaches, sore throats, sinus congestion and other problems, Mr. Smith said.
He said he hoped that the cost to replace the carpeting would come in well under $7,500 for the six classrooms, totaling about 4,800 square feet.
He said the air-quality firm he hired to check the building has reported that the carpet in at least four rooms contained high levels of two bacteria: enterobacter, which is found in animal and human feces, and acinetobacter, usually found only in animal feces.
The report said that in a rural area, the feces probably could have been on the shoes of anyone who entered the school, Mr. Smith said.
"Maybe kids went on a field trip to a farm and tracked it back on their shoes," he guessed. But the school's assistant principal, Ruth Riddle, told him she didn't know of any such field trips recently.
But people in town sometimes walk their dogs on the playground, she told him.
The bacteria may have been tracked into other parts of the building, but have found an especially hospitable environment in the carpet on the ground floor, Mr. Smith said.
The floor is built on a concrete slab that does not have a waterproof layer beneath it, he said.
"The concrete serves as a wick," he said. Moisture can seep up from the ground, through the layers of stone and concrete and up to the carpet.
Meanwhile, a physician with the Maryland Department of the Environment is still studying the results of a telephone survey of parents of all first- and second-graders that requested information about health problems the children had this year.
Also, a group of parents is asking a federal agency, the National Institute for Safety and Health, to lend its expertise to the investigation.