Oct. 5, 2004.ELAINE CAREY
The study looked at 32 women exposed to organic solvents at work for at least eight weeks in their first trimester of pregnancy. It was published today in the journal Archives of Pediatrics and Adolescent Medicine.
The women worked in a variety of occupations and included a hair stylist, lab technicians, graphic designers, embalmers, photo lab workers, conservators and factory workers who were exposed to a total of 78 organic solvents for one to 40 hours a week. Many wore protective equipment at work.
They were matched to a control group of women who had similar incomes and IQs but were not exposed to chemicals. All had voluntarily gone to the Motherisk program at the Hospital for Sick Children, which counsels women on the risks of drugs, chemicals, radiation and infection during pregnancy.
"These are not poor women — they are women who make good salaries, not the working poor," said Dr. Gideon Koren, the study's principal investigator and director of the Motherisk program. "It was very important to say they were not poor so that we could say the symptoms were not the result of that."
They also had not been exposed to lead, alcohol, drugs or heavy lifting, and the children did not differ in birth weight or the age at which they reached developmental milestones.
But the children of the women exposed to solvents, who ranged in age from 3 to 9, had lower scores on a variety of language, memory and dexterity tests than the children in the control group, although their over-all IQs were not affected.
They also had lower behavioural and motor functioning scores and more attention and hyperactivity problems.
All the children were perceived by their mothers as doing well, but "still, when we compare them meticulously to a control group, there were changes that were quite clear and that could not be ignored — and should not," Koren said. "These tendencies are at times more challenging to a child, and clearly, we think women should try to minimize their exposures."
Koren said he wouldn't tell women of childbearing age not to work in professions where they're exposed to solvents, "but we have to recognize that they have to be careful."
While it's reassuring that their over-all IQs were not affected, that measure is not specific enough, he said. "A kid can be very smart, but if hyperactive he will not do very well."
Koren said the small sample size actually made the findings even more significant. "If you get so many statistical differences in 32, it's quite powerful," he said.
"But of course, like everything, this study should be repeated by other people."