Public Release: 

Mount Sinai finds prenatal exposure to certain chemicals affects childhood neurodevelopment

The Mount Sinai Hospital / Mount Sinai School of Medicine

A new study led by Mount Sinai researchers in collaboration with scientists from Cornell University and the U.S. Centers for Disease Control and Prevention, has found higher prenatal exposure to phthalates--manmade chemicals that interfere with hormonal messaging--to be connected with disruptive and problem behaviors in children between the ages of 4 and 9 years. The study, which is the first to examine the effects of prenatal phthalate exposure on child neurobehavioral development, will be published January 28, on the Environmental Health Perspectives website.

"There is increasing evidence that phthalate exposure is harmful to children at all stages of development," said Stephanie Engel, PhD, lead study author and Associate Professor of Preventive Medicine at Mount Sinai School of Medicine. "We found a striking pattern of associations between low molecular weight phthalates - which are commonly found in personal care products - and disruptive childhood behaviors, such as aggressiveness and other conduct issues, and problems with attention. These same behavioral problems are commonly found in children diagnosed with Attention-Deficit Hyperactivity Disorder (ADHD), Oppositional Defiant Disorder, or Conduct Disorder."

Phthalates are part of a group of chemicals known as endocrine disruptors, that interfere with the body's endocrine, or hormone system. They are a family of compounds found in a wide range of consumer products such as nail polishes, to increase their durability and reduce chips, and in cosmetics, perfumes, lotions and shampoos, to carry fragrance. Other phthalates are used to increase the flexibility and durability of plastics such as PVC, or included as coatings on medications or nutritional supplements to make them timed-release.

"Recently, the government instituted regulations limiting certain phthalates in things like child care articles or toys that a young child might put in their mouth," continued Dr. Engel. "But it's their mother's contact with phthalate-containing products that causes prenatal exposure. The phthalates that we found most strongly related to neurodevelopment were those commonly found in cosmetics, perfumes, lotions and shampoos. Current US regulations do not address these kinds of phthalates."

For the study, phthalate metabolite levels were analyzed in prenatal urine samples of a multiethnic group of 404 women who were pregnant for the first time. The women were invited to participate in follow-up interviews when their children were between the ages of 4 and 9. The mothers were not informed of their phthalate metabolite levels and the researchers were unaware of their exposures when testing the children.

Follow-up visits were completed by 188 of the women and their children. At each follow-up visit, the mothers completed validated questionnaires designed to assess their behavior and executive functions. The researchers found that mothers with higher concentrations of low molecular weight phthalates consistently reported poorer behavioral profiles in their children. The strongest trends were in the categories of conduct and externalizing problems, characteristics typically associated with Oppositional Defiant Disorder, Conduct Disorder and ADHD.

"These are high level, chronic exposures that start before the child is even born, but continue throughout their life. More research is needed to examine the effects of cumulative exposure to phthalates on child development. But what this study suggests is that it's not enough to regulate childhood exposure to these chemicals. The regulations need to include products that moms use," said Dr. Engel.

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About The Mount Sinai Medical Center

The Mount Sinai Medical Center encompasses The Mount Sinai Hospital and Mount Sinai School of Medicine. The Mount Sinai Hospital is one of the nation's oldest, largest and most-respected voluntary hospitals. Founded in 1852, Mount Sinai today is a 1,171-bed tertiary-care teaching facility that is internationally acclaimed for excellence in clinical care. Last year, nearly 60,000 people were treated at Mount Sinai as inpatients, and there were nearly 450,000 outpatient visits to the Medical Center.

Mount Sinai School of Medicine is internationally recognized as a leader in groundbreaking clinical and basic science research, as well as having an innovative approach to medical education. With a faculty of more than 3,400 in 38 clinical and basic science departments and centers, Mount Sinai ranks among the top 20 medical schools in receipt of National Institute of Health (NIH) grants. For more information, please visit www.mountsinai.org.

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