Hairdressers are more likely to have babies that are either born small or with major birth defects, suggests research in Occupational and Environmental Medicine. Over 7000 Swedish hairdressers who had gained their diploma at major hairdressing schools between 1970 and 1995 were monitored. A comparison group in other occupations, but matched for age and sex, was also monitored. In Sweden training to become a hairdresser lasts three years, and until 1993 the third year was spent practising in salons.
Between 1973 and 1994, 3706 women gave birth to 6960 babies. These women were surveyed to find out the degree to which they had been exposed to hairdressing chemicals while pregnant.
Around two thirds of the women responded (n = 2410). Their answers showed that compared with the comparison group, hairdressers were more likely to give birth to babies that were small for dates - 4.5 per cent compared with 4.1 per cent. And they had a higher percentage of babies born with birth defects - 2.8 per cent compared with 2.1 per cent.
Although there was no clear link between individual exposure and birth defects, frequent perming and spraying during pregnancy were associated with an increased risk of having a small for dates baby, say the authors.
Other factors, which could have biased the results, such as mother's age, weight, height and smoking habit, had only marginal impact on the results.
The authors conclude that while the risk seems to be moderate, hairspray contains chemicals, such as ethanol and acetone, that have sometimes been linked to reduced birth weight.
One limitation of the study is that alcohol consumption and spouses age and height were not obtained. These may also have a detrimental effect on infant size.
The authors recommend that protective gloves should be worn and that steps should be taken to ensure proper ventilation throughout salons, but especially in mixing areas.