Air pollution and poverty stack the deck for ADHD

October 4, 2017, Columbia University's Mailman School of Public Health

Scientists at the Columbia Center for Children's Environmental Health (CCCEH) at the Mailman School of Public Health report the first evidence that prenatal exposure to polycyclic aromatic hydrocarbons (PAH)—carcinogenic and neurotoxic combustion byproducts commonly found in urban air—combines with material hardship to significantly increase ADHD symptoms in children. Results are online in the journal Environmental Research.

In the latest paper from the ongoing, longitudinal Mothers and Newborns Study in low-income communities of color in New York City, scientists assessed levels of the babies' to PAH by measuring a molecular marker of exposure in maternal blood collected at delivery. Mothers reported their experience of material hardship (lack of adequate food, housing, utilities, and clothing) at multiple time points, from pregnancy to when their child was age 9, at which time researchers assessed the child's ADHD behaviors.

Among 351 children in the study sample, those with higher prenatal PAH exposure generally had more ADHD symptoms than those with low PAH exposure, with the greatest difference in symptoms in children experiencing persistent hardship from pregnancy through childhood.

The new paper is the first to look at the combined effects of PAH exposure and material hardship on ADHD, building on prior research looking at PAH and socioeconomic stress separately. Previously, CCCEH researchers reported that children exposed prenatally to higher levels of PAH and whose mother reported material hardship scored significantly lower on IQ tests at age 7, compared with children born to mothers with greater economic security and less to the pollutants.

During the prenatal period, the fetus is undergoing rapid development, making it highly susceptible to DNA damage and other effects of pollutants such as PAH. PAH can cross the placenta and fetal blood-brain barrier and trigger inflammation that is toxic to the developing brain. Psychosocial stress also promotes inflammation and can be damaging to neurodevelopment. The researchers believe the combination of psychosocial and physical "toxicants" may amplify each other through common inflammation pathways.

Approximately 11 percent of American ages 4-17 have been diagnosed with ADHD. Symptoms of hyperactivity, impulsivity, and inattention often persist and may lead to poor performance in the academic and occupational settings throughout the adult years.

"There is no single trigger for ADHD," says first author Frederica Perera, director of CCCEH and professor of Environmental Health Sciences at the Mailman School. "Air pollution and economic hardship are part of a mix of genetic, environmental, and social factors contributing to childhood behavioral problems, including ADHD. Children would be best served by a multifaceted response that combines economic assistance for women with policy interventions to reduce in urban areas, especially in low-income communities of color."

Explore further: Toxic combination of air pollution and poverty lowers child IQ

Related Stories

Toxic combination of air pollution and poverty lowers child IQ

April 29, 2015
Children born to mothers experiencing economic hardship, who were also exposed during pregnancy to high levels of PAH (polycyclic aromatic hydrocarbons), scored significantly lower on IQ tests at age 5 compared with children ...

Breathing dirty air during pregnancy raises odds of childhood ADHD-related behavior problems

November 5, 2014
Prenatal exposure to polycyclic aromatic hydrocarbons, or PAH, a component of air pollution, raises the odds of behavior problems associated with attention deficit hyperactivity disorder, or ADHD, at age 9, according to researchers ...

Prenatal BPA exposure linked to anxiety and depression in boys

August 16, 2016
Boys exposed prenatally to a common chemical used in plastics may be more likely to develop symptoms of anxiety and depression at age 10-12. The new study by researchers at the Columbia Center for Children's Environmental ...

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

March 17, 2016
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 ...

Prenatal exposure to certain pollutants linked to behavioral problems in young children

April 12, 2011
Mothers' exposure during pregnancy to pollutants created by the incomplete combustion of fossil fuels and other organic material may lead to behavioral problems in their children, according to a new study. Researchers found ...

Air pollution and psychological distress during pregnancy

October 7, 2013
Maternal psychological distress combined with exposure to air pollution during pregnancy have an adverse impact on the child's behavioral development, according to researchers at the Columbia Center for Children's Environmental ...

Recommended for you

After-school programs a blessing for kids with ADHD

May 8, 2018
(HealthDay)—After-school activities might be just what the doctor ordered for kids with attention-deficit/hyperactivity disorder (ADHD), researchers suggest.

Computerized test may help improve ADHD diagnoses

May 4, 2018
The prevalence of attention deficit hyperactivity disorder (ADHD) diagnoses in children and young people has increased, but diagnostic practice among clinicians remains variable, with significant diagnostic delays and reliance ...

Kids with severe brain injuries may develop ADHD: study

March 19, 2018
(HealthDay)—Young children who sustain a severe head injury may struggle with attention problems as they grow older, researchers say.

For children with ADHD, a brief, school-based program can help dramatically with homework problems, study finds

December 6, 2017
Children with attention deficit hyperactivity disorder who took part in a brief, school-based program displayed significant improvements in their homework, organization and planning skills, according to a new study led by ...

What can twitter reveal about people with ADHD?

November 9, 2017
What can Twitter reveal about people with attention-deficit/hyperactivity disorder, or ADHD? Quite a bit about what life is like for someone with the condition, according to findings published by University of Pennsylvania ...

Brain imaging reveals ADHD as a collection of different disorders

November 8, 2017
Researchers have found that patients with different types of attention-deficit/hyperactivity disorder (ADHD) have impairments in unique brain systems, indicating that there may not be a one-size-fits-all explanation for the ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.