Teenagers exposed to toxic air ‘at risk of psychotic episodes’

Teenagers who live in areas of high pollution in the UK are more likely to suffer psychotic experiences, a groundbreaking study reveals today.

The research from King’s College London provides the first known evidence of an “association” between toxic air and mental health problems.

Pollution was already known to be a factor in cardiovascular disease, lung disease, stroke and asthma as well as babies being too small or premature.

Today’s research provides a potential explanation for why growing up in cities such as London is a risk factor for psychosis, at the “less extreme” end of mental disorders.

It is the first time geographical air pollution data has been cross-checked against the addresses and experiences of young people across the UK. Psychotic experiences — such as “hearing voices” or feeling paranoid about being “spied on” — were “significantly more common” among adolescents with the highest exposure to exhaust gases, such as nitrogen dioxide (NO2) and nitrogen oxides (NOx), and PM2.5 soot particles from diesel exhausts, tyres and brakes. Lead author Dr Joanne Newbury said: “Our findings suggest air pollution could be a contributing factor in the link between city living and psychotic experiences.”

She said teenagers exposed to the highest level of NO2, NOx and PM2.5 had respectively 71 per cent, 72 per cent and 45 per cent greater odds of psychotic experiences. About 30 per cent of the 2,232 respondents said they had one or more psychotic experiences between the ages of 12 and 18. This means they are more likely to develop psychotic disorders or attempt suicide in later life.

Dr Newbury said there was a “need to be cautious” as the study did not show that air pollution caused psychotic experiences or increased the risk of suffering from them. Noise pollution from traffic could also play a significant role. It is thought pollution particles cause inflammation in the brain and potentially stunt development, and children living in urban areas are twice as likely as those in rural areas to develop psychosis as an adult.

Co-author Professor Frank Kelly said as vehicles were responsible for the bulk of emissions, improvements in London were likely from the Mayor’s new ultra low emission zone.