Occupational exposure to formaldehyde can cause neurological problems, such as slowed reaction times and impaired memory, at levels well below the current government safety standards, a USC scientist has found.
As many as 1.6 million American workers, including 500,000 in the textile industry, are exposed to formaldehyde, a chemical widely used in the manufacture of plywood and insulation and for treating fabric to make clothing wrinkle resistant.
Since 1981, the U.S. Occupational Health and Safety Administration has been under pressure from unions and other groups to reduce permissible levels of formaldehyde exposure in the workplace. In November, 1985, a U.S. Circuit Court of Appeals in Washington gave OSHA until September, 1987, to promulgate a new limit.
The current limit, adopted in 1970, is three parts per million of formaldehyde in the air over an eight-hour day. In hearings last summer, OSHA tentatively proposed lowering the limit to either 1 or 1.5 parts per million.
The new findings may well add pressure to the agency to lower the standard further; its preliminary results were presented at the summer hearings, but the full results appear in the current issue of the Archives of Environmental Health.
In his study, Dr. Kaye H. Kilburn, a professor of medicine at USC, examined the neurological functions of 305 female laboratory technicians from around the country who had used formaldehyde in preparing human and animal tissues for studies of pathology. The study was undertaken, Kilburn said, because the technicians complained of memory impairment.
Kilburn and his colleagues studied 10 types of neurological functions, including balance, eye-hand dexterity, reaction times, and the ability to recall a story, remember a visual design, and recall digits repeated backwards.
The study was quite difficult, he said, because it had to eliminate other factors such as age, exposure to other chemicals, and cigarette smoking (cigarettes produce formaldehyde). But when such factors were eliminated, he said, researchers found that the technicians did not do as well on the tests as women who had not been exposed to formaldehyde.
"The impairment was relatively minor, in degree, on each of the tests," Kilburn said, "but it stretches across a number of function areas. . . ."
Some of the technicians were retested four years later, Kilburn said. "What we found suggests that, for all intents and purposes, the impairment is permanent," he said.
The average formaldehyde level in the labs was about 1 part per million, Kilburn noted.
A spokesman for OSHA said that the agency is aware of Kilburn's results but cannot discuss them until the new rule is ready.
OSHA's reconsideration of the formaldehyde rule was prompted by a 1979 study which showed that the chemical causes cancer in rats. Several subsequent epidemiological studies have shown at least a slight increase in cancer among people exposed to it. Scientists for the unions, however, argue that those studies have understated the risks.
Dr. Eric Frumin, a health and safety expert for the Amalgamated Clothing and Textile Workers Union, termed Kilburn's results "a significant finding."