Children exposed in the womb to chemicals in cosmetics and fragrances are more likely to develop behavioral problems commonly found in children with attention deficit disorders, according to a study of New York City school-age children published Thursday.
Scientists at Mount Sinai School of Medicine reported that mothers who had high levels of phthalates during their pregnancies were more likely to have children with poorer scores in the areas of attention, aggression and conduct.
Children were 2.5 times more likely to have attention problems that were “clinically significant” if their mothers were among those highest exposed to phthalates, the study found. The types of behavior that increased are found in children with Attention Deficit Hyperactivity Disorder and other so-called disruptive behavior disorders.
“More phthalates equaled more behavioral problems,” Stephanie Engel, a Mount Sinai associate professor of preventive medicine and lead author of the study, said in an interview Thursday. “For every increase of exposure, we saw an increase in frequency and severity of the symptoms.”
The connection was only detected for the types of phthalates used in perfumes, shampoos, nail polishes, lotions, deodorants, hair sprays and other personal care products. No behavioral effects were found for the phthalates used in vinyl toys and other soft plastics.
A federal law that went into effect a year ago bans phthalates in children’s vinyl toys and other products. But there are no U.S. restrictions on phthalates in cosmetics and other personal care items. They are, however, banned in cosmetics sold in Europe. Manufacturers of the products maintain that the chemicals are safe after being widely used for about 50 years.
Scientists said the study has uncovered a new problem that could be related to phthalates - effects on a child’s developing brain. Until now, most research has focused on their potential to block male hormones and feminize boys or contribute to male reproductive problems.
“Clearly environmental toxicants play a role in child neurodevelopment, and phthalates, in particular, have been understudied in this area,” Engel said.
Dr. Philip Landrigan, a pediatrician at Mount Sinai and director of the Children's Environmental Health Center, called it “a new area of concern” about phthalates.
“Clearly it needs to be replicated, as does any study that breaks new ground, but the study itself is very well done and very credible,” he said.
The research involved 188 children between the ages of 4 and 9 who were born between 1998 and 2002, according to the study published online in the journal Environmental Health Perspectives. Most were from East Harlem or the Upper East Side of Manhattan, and three-quarters of them were low-income.
The children’s scores were based on the answers that their mothers provided to standardized questions commonly used by psychiatrists and other clinicians to help diagnose attention deficit disorders. The mothers responded to 130 questions designed to detect problematic behaviors on a 4-point scale ranging from “never” to “almost always" and to 86 questions on another test designed to measure cognitive function, such as memory.
Some effects were stronger in boys than girls, but the associations to the chemicals were still considered significant in the girls, Engel said.
The researchers did not use doctors or other clinicians to evaluate the children. Instead, the findings were based on the mothers’ evaluations.
"A parent's report about a child's behavior is certainly subjective,” Engel said. But she added that mothers have been found to be very accurate in assessing poor conduct, aggression and attention problems.