Air pollution and autism: How exposure during pregnancy can disrupt development of fetal brain

Pregnancy complications: Fine particulate matter (PM2.5), often emitted from vehicles and industrial sources, can penetrate deep into the lungs and bloodstream, making their way to the placenta and potentially disrupting brain development (Image: Canva)

Air pollution has been topping the charts of harmful health hazards in recent weeks, with concerns growing over its widespread effects on both the environment and public health. While the dangers of pollutants such as smog and vehicle exhaust are well known, a recent research has uncovered a troubling connection between air pollution and autism spectrum disorder (ASD) in children. According to new studies, exposure to common air pollutants during pregnancy may increase a child’s risk of developing ASD, potentially altering the course of their neurological development before birth.

It is not uncommon for pregnant women to walk through a busy street covered in a haze of car exhausts and industrial emissions. However, what may seem normal, could be affecting her unborn child. A recent study, published in Brain Medicine, suggests that ultra-small pollutants, particularly fine particulate matter (PM2.5) and nitrogen oxides (NO), can have a profound effect on a child’s developing brain. These pollutants, which originate primarily from traffic, industrial activity, and the burning of fossil fuels, are most harmful during the prenatal period when the brain is rapidly developing. The researchers found that the timing of exposure is crucial, with heightened vulnerability during prenatal development.

Pollutants that  affect brain development:

• Fine particulate matter (PM2.5): These tiny particles, often emitted from vehicles and industrial sources, can penetrate deep into the lungs and bloodstream, making their way to the placenta and potentially disrupting brain development.

• Nitrogen oxides (NO): Released during the combustion of fossil fuels, these pollutants have been linked to various neurological disorders, including ASD, by affecting brain functions during critical developmental stages.

• Timing of exposure: The study shows that exposure to these pollutants during the early stages of pregnancy, when the brain is still forming, poses the greatest risk to a child’s development.

• Genetic factors: Those with a genetic predisposition for autism may be particularly vulnerable to the effects of air pollution. Studies suggest that as much as 80 percent of autism cases may be hereditary, and pollutants may amplify the risk in genetically predisposed individuals.

• Disruption of brain function: Pollutants can interfere with how the brain transmits chemical signals, processes hormones, and carries out critical chemical reactions necessary for proper brain growth and function.