A new study from Monash University has linked industrial emissions, fine particles from vehicle exhaust, and other sources of air pollution to an increased risk of autism. The study was focused on children in Shanghai from birth to three years old, who were found to be 78 percent more likely to develop autism spectrum disorder (ASD) when exposed to long-term air pollution.
For the investigation, 124 ASD children and 1,240 healthy children were examined over a nine-year period. While previous research has linked prenatal air pollution exposure to ASD in children, this study is the first to analyze the potential for this association in early life.
Study co-author Yuming Guo is a professor in Monash University’s School of Public Health and Preventive Medicine.
“The causes of autism are complex and not fully understood, but environmental factors are increasingly recognized in addition to genetic and other factors,” said Professor Guo. “The developing brains of young children are more vulnerable to toxic exposures in the environment and several studies have suggested this could impact brain function and the immune system.”
“These effects could explain the strong link we found between exposure to air pollutants and ASD, but further research is needed to explore the associations between air pollution and mental health more broadly.”
According to the World Health Organization, air pollution is the cause of up to 4.2 million deaths every year. Professor Guo explained that global air pollution is rapidly becoming worse, and there is no safe level of exposure.
“The serious health effects of air pollution are well-documented, suggesting there is no safe level of exposure. Even exposure to very small amounts of fine particulate matter have been linked to preterm births, delayed learning, and a range of serious health conditions, including heart disease.”
The current study analyzed the health impacts from three types of particulate matter including PM1, PM2.5, and PM10. These airborne particles are produced by emissions from factories, vehicle exhaust, road dust, and construction. Experts have established that the smallest airborne particles are more capable of penetrating the lungs and entering the bloodstream, which can lead to serious health issues.
“Despite the fact that smaller particles are more harmful, there is no global standard or policy for PM1 air pollution,” explained Professor Guo. “Given that PM1 accounts for about 80% of PM2.5 pollution in China alone, further studies on its health effects and toxicology are needed to inform policy makers to develop standards for the control of PM1 air pollution in the future.”
The study is published in the journal Environment International.