By Janet Raloff
Over the years, many studies have linked skin rashes in some people to working long hours at personal computers. A Swedish study now finds a possible explanation: Certain computer monitors emit a chemical that can cause allergic reactions.
Three years ago, while analyzing pollution in samples of outdoor air, Conny –stman and his colleagues at Stockholm University realized that something in their lab was tainting the glassware they used. It was triphenyl phosphate, a flame retardant added to many plastics.
The chemists eventually traced this contact allergen—which they later also found in the air of schools, daycare centers, and offices—to computers.
In the new study, the scientists tested 18 computers, each a different model. The plastic case on 10 of the monitors contained up to 10 percent triphenyl phosphate by weight. When turned on, the monitors’ heat caused the compound—which is not bound to the plastic—to start evaporating. Soon, a small but measurable amount of the pollutant tainted the air.
The emissions dropped quickly, however. After 10 days of operation, they had fallen to one-third the initial amount, the chemists report in the September Environmental Science and Technology. After the equivalent of 2 years of office use, the monitors emitted the chemical at just 10 percent of their initial rate.
There’s no way for a consumer to identify which monitors harbor triphenyl phosphate, –stman observes. In fact, he obtained manufacturers’ documentation on all the polluting monitors stating that they didn’t contain the flame retardant.
–stman says his team is expanding its search to other air pollutants emitted by computers and to other electronic products that might be polluting indoor air. He notes, for instance, that after one of his coworkers bought a new television, “we analyzed the air in his living room and found nearly three times the triphenyl phosphate [concentrations] that we measured from new computers.”
There are other flame retardants that chemically bond to plastic and so won’t evaporate during a device’s operation. Using them, –stman notes, would “eliminate unnecessary chemical exposure [to a known allergen].”
