New study reveals what parents need to know about the link between air pollution and autism

A recent study published in the journal Brain Medicine has added to the growing body of research suggesting a connection between air pollution and the risk of autism spectrum disorder (ASD). The findings highlight how prenatal exposure to the chemicals commonly found in car emissions may affect fetal brain development during critical periods.

How exposure to air pollution affects fetal brain development

Professor Haitham Amal, senior author of the study, explained: “Different kinds of neurological disorders, including autism spectrum disorder, can be associated with [pollutants]. The timing of exposure appears crucial, with heightened vulnerability during prenatal development.” The researchers also found a connection between autism and exposure to pollutants before conception.

Related: New study finds no link between acetaminophen use during pregnancy and autism and ADHD

Autism: A complex condition influenced by multiple factors

The causes of autism are believed to be complex. While genetics play a significant role in autism—an estimated 80% of cases are believed to have hereditary links, according to UCLA—this new study underscores the importance of environmental factors as part of a more complex picture. According to researchers, pollutants may cross the placenta and disrupt fetal brain growth through various biological pathways, including interference with the body’s chemical messaging systems and hormone functions.

The role of environmental factors in autism development

Dr. Andy Shih, Chief Science Officer at Autism Speaks, told Motherly: “In terms of causation, research suggests that autism develops from a combination of genetic and nongenetic, or environmental, influences. 

The study reinforces findings from several studies, specifically those from Heather Volk, 2013 (partly funded by Autism Speaks), that share that exposure to traffic-related air pollution, nitrogen dioxide, PM2.5, and PM10 during pregnancy and the first year of life was associated with autism.”

(PM2.5 and PM10 refer to particulate matter, which are tiny particles in the air, often found in vehicle emissions. They can enter the lungs and even the bloodstream, potentially affecting brain development during critical periods like pregnancy and early childhood.)

Further, epidemiological and toxicological examinations of likely biological pathways are needed to help determine whether these associations are causal.” In short, Dr. Shih emphasizes the need for more research to confirm whether these pollutants directly cause autism or if there are other contributing factors involved.

Related: 1 in 36 kids in the U.S. are diagnosed with autism, CDC says

The importance of clean air for children and families

The American Academy of Pediatrics (AAP) has long recognized the health hazards of air pollution to children. In their policy statement, they note that current levels of air pollutants are associated with many pediatric morbidities, including adverse birth outcomes like low birth weight and preterm birth, as well as behavioral and cognitive development issues. They emphasize that “air pollution exposures are widespread, and children are uniquely vulnerable.” 

All of this information, we know, can feel overwhelming to parents who want to keep their babies safe, but are raising families in an increasingly polluted world. Solving the climate crisis and fighting for clean air are important, yet it will take decades to make the air and overall environment safer for families.

What can parents do today to protect their children?

While experts stress that these findings require further research, they also emphasize the importance of protective measures for pregnant women living in areas with high pollution levels.

As a parent or someone planning for a family, this research serves as a reminder of the importance of advocating for clean air policies and making small changes where possible—whether by investing in indoor air purifiers, reducing exposure to high-traffic areas, or supporting community efforts to address pollution.

As we continue to learn more about the complex interplay of genetics and environment, one thing is clear: supporting parents means supporting healthier futures for all. 

Sources:

1. Air pollution: an emerging risk factor for autism. 2024. Brain Medicine Genomicpress. Air pollution: an emerging risk factor for autism spectrum disorder.
2. Air pollution may increase risk of a child developing autism. 2024. Science Focus. Air pollution may increase risk of a child developing autism.
3. As pollution increases, world falls further behind climate targets. 2024. NOAA Research. As pollution increases, world falls further behind climate targets.
4. Outdoor Air Pollutants. American Academy of Pediatrics. Outdoor Air Pollutants.
5. Traffic-related air pollution, particulate matter, and autism. 2013. National Library of Medicine. Traffic-related air pollution, particulate matter, and autism.
6. Is Autism Genetic? 2024. UCLA Health. Is Autism Genetic?