Air Pollution and Early Stress Can Lead to Cognitive Difficulties in Children: Study
Sun, April 18, 2021

Air Pollution and Early Stress Can Lead to Cognitive Difficulties in Children: Study

In a recent study, researchers found out that air pollution and exposure to early life stress can lead to cognitive difficulties in children. / Photo by Vadym Marty via 123RF


In a recent study published by Our World in Data, a scientific online publication that focuses on large global problems, researchers found out that air pollution and exposure to early life stress can lead to cognitive difficulties in children. Cognitive difficulties can include Attention-Deficit/Hyperactivity Disorder (ADHD), which is a chronic condition that affects millions of children and can persist until adulthood. In 2017, most cases of ADHD have been reported in Australia that affects 2.53% of their total pollution, followed by Turkey with 2%, and New Zealand with 1.91%, as reported on Our World in Data. 


All About Air Pollution

According to the Natural Resources Defense Council, a United States-based 501 non-profit international environmental advocacy group with headquarters in New York City, air pollution refers to the release of different gaseous pollutants into the air and they are considered to be detrimental to human health and the planet as a whole. Most air pollution comes from energy use and production. For example, the burning of fossil fuels releases gases and chemicals into the air. Air pollution does not only contribute to climate change but it is also exacerbated by it. Another type of air pollution is worsened by increased heat, such as smog, which is formed when the weather is warmer and there is more ultraviolet radiation. 

Moreover, hazardous air pollutants can cause severe health risks in small amounts. Benzene, which is classified as a carcinogen by the EPA, can cause eye, skin, and lung irritation in the short term and also blood disorders in the long term. Also, dioxins can affect the liver in the short term and harm the body’s immune, nervous, and endocrine system in the long run. 

Effects of Air Pollution and Early Childhood Stress

Researchers from the Columbia University Mailman School of Public Health and Columbia Psychiatry claim that children who are exposed to early life stress at home and elevated prenatal exposure to air pollution are more likely to have symptoms of attention and thought problems. Early life stress is most common in children from disadvantaged backgrounds who also live in areas with greater exposure to air pollution. The study was published in the Journal of Child Psychology and Psychiatry. 

This new study is one of the first to examine the effects of air pollution and early life stress on school-age children. It is already known that air pollution has negative effects on physical health and it can also have negative effects on mental health. Life stress is also one of the most common contributors to poor mental health in children and adults. According to Dr. David Pagliaccio, an assistant professor of clinical neurobiology in psychiatry at Columbia Psychiatry and the first author of the study, prenatal exposure to polycyclic aromatic hydrocarbons, which is the neurotoxicant commonly found in air pollution, seems to sustain the effects of early life social and economic stress on the mental health in children. 

Dr. Amy Margolis, an assistant professor of medical psychology in psychiatry at Columbia Psychiatry and the senior author of the study, added that air pollutants are common in our environment especially in cities and given the socioeconomic inequities and environmental injustice, children who grow up in disadvantaged circumstances are the ones who are more likely to experience both early life stress and exposure to neurotoxic chemicals during childhood. 

The data that the research team collected were from the CCCEH Mothers and Newborns longitudinal birth cohort study in Northern Manhattan and the Bronx. Many of the participants self-identified as African American or Dominican. Mothers wore an air monitoring backpack during the third trimester of pregnancy to measure the exposure of air pollutants in their daily lives. Then when the children were 5 years old, the mothers reported on the stress levels on their lives, and this includes neighborhood quality, material hardship, intimate partner violence, perceived stress, lack of social support, and general distress levels. The mothers also had to report on their child’s psychiatric symptoms at the ages of 5, 7, 9, and 11. 

According to Dr. Julie Herbstman, an associate professor of environmental health science and the director of the Columbia Center for Children’s Environmental Health at Columbia Mailman School of Public Health, these exposures add to the combined effect on poor mental health. She added that authorities should point out the importance of public health programs that lessen the exposure to these critical factors in order to improve both the physical and psychological health of children and mothers. 

The combined effect of air pollution and early life stress are seen across several mental attention problems such as attention-deficit/hyperactivity disorder or ADHD and it can already manifest at the age of 11 or younger. According to the Mayo Clinic, a nonprofit academic medical center based in Rochester, Minnesota, focused on integrated clinical practice, education, and research, ADHD is a chronic condition that affects millions of children and it can persist until adulthood. It includes a combination of persistent problems such as difficulty sustaining attention, hyperactivity, and impulsive behavior. Moreover, children with ADHD can also struggle with low self-esteem, troubled relationships, and poor performance in school. 

Symptoms of ADHD can include inattention and hyperactive-impulsive behavior and, in some children, they are noticeable as early as three years of age. The symptoms can also be mild, moderate, or severe and can continue into adulthood. Inattention may often pertain to the failure of the child to consider details or to make careless mistakes, have trouble staying focused on tasks, appear not to listen, have difficulty in following through on instructions, and dislikes tasks that require mental effort such as schoolwork. 

However, not all inattentive children have ADHD. It is typical for preschoolers to have short attention spans and be unable to stick with one activity for too long. Even normal teenagers have short attention spans and it often depends on their level of interest. But when the problems in school and at home become too severe than normal and the child is not able to maintain healthy regular friendships, then it can be a symptom of ADHD. 

How to Protect Children From Air Pollution

It is not the easiest task since clean air is not easily accessible especially in highly urbanized areas. However, parents can always tune in on the radio or see the weather report whether the pollution levels are high or low and they can limit the time when children go outside or when they do go outside they can stay away from heavily trafficked roads. When the air quality is bad, it is best to just stay indoors with the windows closed. Lastly, it is also important to wear sunscreen because ultraviolet radiation comes through the weakened ozone layer and it can cause skin damage and even cancer.