Autism risk could rise with air pollution, study suggests

A new study led by Hebrew University of Jerusalem suggests that air pollution, particularly the type emitted in car exhaust, could be a trigger for Autism spectrum disorder (ASD) and other neurodevelopmental disorders. The findings, published in the journal Brain Medicine, analyzed multiple studies related to autism and cellular activity.

The researchers focused on four specific types of particles that make up air pollution: fine particulate matter (PM), nitrogen oxides (NO, NO2), sulfur dioxide (SO2), and ozone (O3). They investigated four different ways in which these particles could impact the fetus, including neuroinflammation, oxidative/nitrosative stress, epigenetic modifications, and disruptions to neurotransmitters.

Lead study author Haitham Amal, PhD, an associate professor at The School of Pharmacy at Hebrew University of Jerusalem, explained that the risk of neurodevelopmental disorders, especially ASD, is significantly raised due to gene-environment interactions. The brain is most susceptible to external factors during times of accelerated development, such as the prenatal and early childhood periods.

Georges Ghacibeh, M.D., a neurologist at Hackensack University Medical Center in New Jersey, who was not involved in the study, emphasized that the brain undergoes significant changes from conception until about age 5, making it more susceptible to the impact of external factors during this period.

Another study by the same research team found that nitric oxide (NO), one of the particles in air pollution, is a key factor in autism. Ghacibeh explained that chemicals inhaled by pregnant mothers or young children can affect various metabolic pathways, interfering with normal brain development and causing brain cells to lose their function.

While the study had limitations and did not prove causation, future research should focus on understanding pollution’s effects on genetically susceptible individuals and developing ways to protect those at greatest risk. Amal suggested that this knowledge could inform public health policies aimed at minimizing ASD risk from environmental pollutants.

Living in areas with lower pollution levels, using air filters, and maintaining good nutrition while limiting exposure to smoking, alcohol, and drugs can help mitigate the risks associated with air pollution. The study was funded by grants from the U.S. Department of Defense (DoD) and the Eagles Autism Foundation, among others.

In conclusion, the study highlights the potential link between air pollution and neurodevelopmental disorders, emphasizing the importance of further research and public health interventions to address this issue.