Hairdressers have slightly smaller babies
Birth defects also more common, Swedish study finds.
"Hairdressers are more likely to give birth to slightly smaller babies or to babies
with birth defects.
That's the conclusion of a new Swedish study, but the increased risks were found
to be moderate. And an American genetics expert says there's no cause for alarm
for hairdressers or their clients.
Researchers from the University Hospital in Lund, Sweden, compared the responses
of 2,410 hairdressers who had given birth with the responses of 3,462 non-hairdressers
who had given birth during the same 21-year period, 1973 to 1994. The hairdressers
supplied details about their working hours and their exposure to shampoos, permanent
waves, sprays and other chemicals commonly used in salons.
Hairdressers were more likely to give birth to babies that were small for their
gestational age - 4.5 percent of the hairdressers had low birth-weight babies, compared
to 4.1 percent of the women who did not work as hairdressers. Low birth-weight babies,
defined as weighing less than 5.5 pounds, are more prone to health problems.
The hairdressers' babies weighed 7.6 pounds, on average, while the non-hairdressers'
babies averaged 7.7 pounds.
Hairdressers who reported performing frequent permanent waving and spraying tended
to have the lower birth-weight infants, the researchers found. Those who worked
more than 30 hours a week during pregnancy also were more likely to have small babies.
Hairdressers also had more babies born with birth defects - 2.8 percent of hairdressers'
babies had birth defects, compared with 2.1 percent of babies born to non-hairdressers.
"It is no problem for the customers, just for the workers," says Dr. Kjell Toren,
an associate professor at the Institute of Internal Medicine at Sahlgrenska University
Hospital in Gothenburg, one of the study authors.
The birth defects among the hairdressers' children included spina bifida, cleft
palate and lip, heart defects, bladder problems, limb abnormalities and Down's syndrome.
But a Los Angeles genetics expert says that there's no cause for alarm, and that
the chemicals might not be entirely to blame for the findings.
"Low birth-weight could be associated with standing on the feet all day," says Dr.
Karen Filkins, an associate professor of obstetrics and gynecology at the UCLA School
of Medicine. The reduced uterine blood flow, a result of excess standing, could
cause the baby not to grow as much, she says.
Filkins also points out that the differences between hairdressers and non-hairdressers,
both in terms of defects and birth weights, was not that great. The moderate increases
in both birth defects and low birth weight could have happened "by chance," she
says.
The researchers' study appears in the current issue of Occupational and Environmental
Medicine.
Even so, the Swedish researchers recommend the regular use of protective gloves
by hairdressers, especially during pregnancy.
"In general, the exposure must be minimized," Toren says. He recommends "working
with protective gloves and local ventilation in mixing rooms."
Conditions are improving in Sweden, he says. "In Sweden, this research has initiated
improved ventilation and improved handling of chemicals in this business."
For pregnant women, Filkins says, there's less concern than for hairdressers because
they aren't exposed to the chemicals on a daily basis.
Her advice for pregnant women who might be worried about the effects of hair chemicals
on their unborn infants?
"Wait until after the first trimester [to get hair colored] to minimize the risk
further," she says."