Identifying and indoor air threat.

Researchers taking a white glove to nine office buildings around the country where workers reported symptoms such as sore throat and dizziness have uncovered a new indoor air pollutant. The culprit is mineral fibers, such as fiberglass, often used in thermal and acoustic insulation in ventilation systems and ceilings, report Alan Hedge and his colleagues at Cornell University in Ithaca, N.Y., in PROCEEDINGS OF INDOOR AIR '93, published in November.

The extent of the problem is unknown, but the fibers get loose "very easily," hang out in dust, and irritate people's eyes and throats, Hedge says. Installing an air filtration system solved the problem, he adds.

Exposure to the fibers, primarily silicon oxide or calcium oxide, was known to cause breathing and other problems, the researchers write. But the fibers had not been linked to "sick building syndrome," in which people complain that their office environment is making them ill, says Hedge.

Of the six pollutants the researchers studied, including nicotine, only the amount of fibers in the dust correlated with workers' complaints. Previous research has tied sick building syndrome to poor ventilation and excessive amounts of volatile organic compounds, such as benzene, in the air, Hedge says.