Autistic children face an increased risk of hospitalisation if exposed to air pollution for relatively brief periods, with boys more at risk than girls, new research suggests. Admissions for issues such as hyperactivity, aggression or self-injury may be prevented by minimising their exposure, and cutting air pollution levels could lower the risks, the researchers behind the study concluded. The findings were published in the journal BMJ Open. “Short-term exposure [to air pollution] was associated with a higher risk of hospital admissions for autism spectrum disorder,” the researchers wrote. “The associations were demonstrated to be more prominent among boys than among girls in sex-stratified analyses.” Autism spectrum disorder (ASD) is a neurodevelopmental disorder with a range of symptoms and severity. It is often accompanied by neuroinflammation and systemic inflammation meaning drugs, supplements and diet can improve the core symptoms, according to the report in the BMJ Open. It is believed that exposure to air pollution in the short-term, over several days or weeks for instance, can induce systemic inflammation and neuroinflammation, potentially increasing the risk of hospital admission in autistic people. But previous studies have focused on the association between long-term exposure to air pollution over years during pregnancy and the early postnatal period, and ASD development among children. The researchers sought to find out if short-term exposure may also pose a risk of aggravating ASD symptoms among school-age children. A child’s developing nervous system is more susceptible to environmental exposures than an adult’s, the report said. Globally, one in 100 children are autistic, according to the World Health Organization. Researchers from the Institute of public health and medical care at Seoul National university hospital drew on official government data on daily hospital admissions for autism among children aged five to 14 between 2011 and 2015. They also collected data on national daily levels of fine particulate matter (PM2.5), nitrogen dioxide (NO2), and ozone (O3) in each of the 16 regions in the Republic of Korea. Analysis of the data revealed that short-term exposure to PM2.5, NO2 and O3 was associated with a heightened risk of hospital admission for autism, and that boys were at greater risk than girls. The researchers acknowledged limitations to the study and called for further research in the area. “This study suggests that short-term exposure to air pollution affects ASD symptom aggravation, which is more prominent among boys than among girls,” the researchers concluded. “Air pollution mixtures were also found to be associated with ASD symptom aggravation, mostly driven by PM2.5 and NO2. “These results emphasise that reduction of air pollution exposure needs to be considered for successful ASD symptom management, which is important with regard to quality of life and economic costs. “Because this is the first study on this subject, further studies, especially studies directly investigating ASD symptoms in more detail, are warranted to confirm the results and draw policy implications.”