Public Release: 

Prenatal exposure to air pollution linked to impulsivity, emotional problems in children

Columbia University's Mailman School of Public Health

Exposure to common air pollutants during pregnancy may predispose children to problems regulating their thoughts, emotions, and behaviors later on, according to a new study led by researchers at the Columbia Center for Children's Environmental Health within Columbia University's Mailman School of Public Health and New York State Psychiatric Institute. The new study is the first of its kind to examine the effects of early life exposure to a common air pollutant known as PAH (polycyclic aromatic hydrocarbons) on self-regulating behaviors and social competency that incorporates multiple assessment points across childhood. Children with poor self-regulation skills have difficulty managing disruptive thoughts, emotions, and impulses; poor social competency limits their ability to get along with others. The study appears in the Journal of Child Psychology and Psychiatry.

PAH are ubiquitous in the environment from emissions from motor vehicles; oil, and coal burning for home heating and power generation; tobacco smoke; and other combustion sources. (More on PAH and ways to limit exposure can be found on the CCCEH website.) Prenatal exposure to PAH has been associated with ADHD; symptoms of anxiety, depression and inattention; and also behavioral disorders, which are all thought to be related to deficits in self-regulation.

Lead investigator Amy Margolis, assistant professor of medical psychology in the Department of Psychiatry at Columbia University Medical Center and New York State Psychiatric Institute, and colleagues analyzed maternal blood samples and child tests results from 462 mother-child pairs, a subset of CCCEH's ongoing urban birth cohort study in New York City, from pregnancy through early childhood. Maternal exposure to PAH was determined by presence of DNA-PAH adducts in a maternal blood sample.

Children were tested with the Child Behavior Checklist at ages 3-5, 7, 9, and 11. Scores obtained from the CBCL were used to create a composite score for the Deficient Emotional Self-Regulation Scale (DESR), and higher scores on the DESR indicated reduced capabilities to self-regulate. Investigators found that children whose mothers had higher exposure to PAH in pregnancy had significantly worse scores on the DESR at ages 9 and 11 than children whose mothers had lower exposure to PAH in pregnancy. Over time, low-exposure children followed a typical developmental pattern and improved in self-regulatory function, but the high-exposed children did not, underscoring the long-term effect of early-life exposure to PAH. Additionally, researchers found that DESR score had a mediating effect on tests of social competence, indicating that self-regulation is an important factor in developing social competence.

The evidence that prenatal exposure to PAH leads to long-term effects on self-regulatory capacities during early and middle childhood suggests that PAH exposure may be an important underlying and contributing factor to the genesis of a range of childhood mental health problems. In terms of a potential mechanism, researchers suggest that prenatal exposure to PAH damages neural circuits that direct motor, attentional, and emotional responses. Further deficits in self-regulation may predispose children to becoming engaged in high-risk adolescent behaviors.

"This study indicates that prenatal exposure to air pollution impacts development of self-regulation and as such may underlie the development of many childhood psychopathologies that derive from deficits in self-regulation, such as ADHD, OCD, substance use disorders, and eating disorders," says Margolis.

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Support for the study was provided by the National Institute of Environmental Health Sciences (NIEHS) and the U.S. Environmental Protection Agency (US EPA): NIEHS/EPA P01ES09600/R82702701, NIEHS/EPA P01ES09600/RD83214101, NIEHS/EPA P01ES09600/RD83450901, NIEHS R01ES08977, NIEHS R01ES015579; and the National Institute on Drug Abuse (NIDA): NIDA R01DA027100, NIDA R01ES015282. The study was also made possible in part by the New York Community Trust, the Blanchette Hooker Rockefeller Foundations, and the John and Wendy Neu Foundation. The authors declare no conflicts.

Co-authors include Virginia Rauh, Julie Herbstman, Frederica Perera, Deliang Tang, Ya Wang, Shuang Wang, and Valerie Thomas from Columbia's Mailman School; Katie Davis of Columbia University Medical Center; and Bradley Peterson from the University of Southern California.

The Columbia Center for Children's Environmental Health

The Columbia Center for Children's Environmental Health was founded in 1998 when an interdisciplinary team of researchers at Columbia University, led by Frederica Perera, was awarded the distinct status of becoming one of eight Centers for Children's Environmental Health and Disease Prevention by the National Institute of Environmental Health Sciences (NIEHS) and the Environmental Protection Agency (EPA). The Center's seminal research has shown that exposure to air pollutants such as polycyclic aromatic hydrocarbons (PAH), pesticides, and chemicals such as flame-retardants, bisphenol A (BPA) and phthalates during the sensitive fetal and early childhood periods can increase risk of asthma, cognitive and behavioral problems, and obesity in childhood. In order to prevent childhood illness and developmental impairment, the Center communicates study findings to policymakers and shares information with community members to protect children's health.

Columbia University's Mailman School of Public Health

Founded in 1922, Columbia University's Mailman School of Public Health pursues an agenda of research, education, and service to address the critical and complex public health issues affecting New Yorkers, the nation and the world. The Mailman School is the third largest recipient of NIH grants among schools of public health. Its over 450 multi-disciplinary faculty members work in more than 100 countries around the world, addressing such issues as preventing infectious and chronic diseases, environmental health, maternal and child health, health policy, climate change & health, and public health preparedness. It is a leader in public health education with over 1,300 graduate students from more than 40 nations pursuing a variety of master's and doctoral degree programs. The Mailman School is also home to numerous world-renowned research centers including ICAP (formerly the International Center for AIDS Care and Treatment Programs) and the Center for Infection and Immunity. For more information, please visit http://www.mailman.columbia.edu.

New York State Psychiatric Institute and Columbia University Department of Psychiatry(NYSPI/Columbia Psychiatry)

NYSPI/Columbia Psychiatry holds the top ranking in US News and World Report and in NIH research funding among the psychiatric departments and research facilities in the nation, and has contributed greatly to the understanding and treatment of psychiatric disorders. Located at the New York State Psychiatric Institute on the NewYork-Presbyterian Hospital/Columbia University Medical Center campus in Washington Heights, the institute and department enjoy a rich and productive collaborative relationship with physicians in various disciplines at Columbia University's College of Physician's and Surgeons. NYSPI/Columbia Psychiatry is home to distinguished clinicians and scientists noted for advancing the field in basic research and in the diagnosis and treatment of depression, suicide, schizophrenia, bipolar and anxiety disorders, eating disorders, and childhood psychiatric disorders.

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