Women who are exposed to radiation from video display terminals do not appear to have a higher risk of miscarriages, according to a long-awaited federal government study published today in the New England Journal of Medicine.
However, several independent work-safety advocates said that more research is needed to conclusively prove that VDT radiation is not hazardous.
The seven-year study, done in eight Southeastern states, compared the pregnancies of 323 young telephone operators who worked with VDTs and 407 who worked in similar jobs without VDTs. It is the latest in a series of conflicting analyses of whether low-level radiation emitted by the machines affects the female reproductive system.
Conducted by the National Institute for Occupational Safety and Health, the study found that 14.8 percent of pregnant women who worked at VDTs reported miscarriages, compared with 15.9 percent for women who did not work at VDTs -- a statistically negligible difference. Both figures fell within medical research estimating that the miscarriage rate for the general population of pregnant women is 11 percent to 20 percent.
"I think the study is reassuring for women who are concerned about working with VDTs and the subsequent risk of miscarriages," said Dr. Teresa M. Schnorr, principal author of the report. "This was the most detailed and the most focused study performed on miscarriages and VDT technology."
Past studies have suggested that appliances such as VDTs and electric blankets were responsible for increased rates of miscarriages. Other, more recent studies of VDTs contradicted those findings.
The concern has been strong enough to persuade some U.S. computer makers to introduce terminals that are shielded to reduce some low-frequency electromagnetic radiation.