Children who breathe in toxic air may be at a higher risk of growing up with autism spectrum disorder (ASD), new research suggests.
Researchers discovered youngsters living in highly polluted parts of Shanghai have a 86 per cent greater chance of developing ASD.
The scientists, based at Monash University in Australia, said children are most at risk in their first three years of life.
Lead author Dr Yuming Guo said: ‘The developing brains of young children are more vulnerable to toxic exposures in the environment.’
Exposure air pollution early in childhood can significantly raise the risk of developing symptoms associated with autism, a new study has found. Those aged two and three are most at risk
ASD is the name for a range of conditions, including Asperger syndrome, that affect a person’s social interaction, communication, interests and behaviour.
Figures estimate about one in every 100 people in the UK has ASD, and more boys are diagnosed with the condition than girls.
Currently, the exact cause of ASD is unknown.
The latest study, published in Environment International, has gone a step further to throw up some clues about its potential cause.
Nearly 1,500 children were included in the research. Of those, 124 had ASD, while 1,240 were not considered to be on the spectrum.
The children were selected from primary schools and kindergartens in Shanghai in 2014, and were between three and 12 years of age.
The researchers then matched daily readings of pollution particles with where the children lived in the first three years of the life.
The study looked at three sizes of particles – referred to as PM1 (the smallest variety), PM2.5 and PM10.
Dr Guo and colleagues saw a clear link, with children most likely to be diagnosed with ASD if exposed to tiny pollutants.
The team of scientists are unsure why, but they suspect disruptions to the immune system could be at least partially to blame.
Inhalable particles up to 10 micrometres in size are a major source of air pollution around the world.
They include fine bits of carbon, sulphur oxides, and organic compounds produced by traffic, industrial processes, and fossil fuel burning.
Dr Guo said PM1 contributed to an even greater risk of children developing autism, and added ‘there is no safe level of exposure to air pollutants’.
There are a multitude of health conditions linked with air pollution, mostly involving cardiovascular and pulmonary disease.
The research comes after the World Health Organization (WHO) revealed 90 per cent of the world’s children are breathing unsafe air.
The WHO also states that more than four million people die each year from outdoor air pollution.
The deaths are mainly due to heart disease, stroke, chronic obstructive pulmonary disease, lung cancer, and acute respiratory infections in children.