Air pollution cause psychotic experiences

Teens living in place with dirty air have 70% more likely to have symptoms like paranoia. That’s what the study had found by analyzing the experiences of more than 2,000 17-year-olds boys and girls across England and Wales. The main cause of dirty air is nitrogen oxides, which have reached high levels. It comes from diesel vehicles and it is at illegal levels in most British towns and cities. 

People growing up in cities were already known to have more psychotic experiences than those outside urban areas (toxic air is one potential reason), but this type of study can’t prove a causal link, and other factors such as noise could be important. Psychotic experiences are much more common in adolescents than in adults, but young people who today suffer from these problems will inevitably have them later, and scientists are particularly keen to uncover the reasons for mental ill health in urban centres.

The new study, published in the journal "Jama Psychiatry", combined high-resolution air pollution data and psychotic experiences observed by the adolescents in private interviews. A third of the young people from urban areas, one fifth being rural and the rest suburban. Psychotic experiences were significantly more common among teens living in the top 25% most polluted places. The study took into account other potential causes of psychotic experiences, like smoking, alcohol, drugs. «The nitrogen oxides explained about 60% of the associations between urban living and psychotic experiences» said Joanne Newbury at King’s College London, who led the research. The research is linking air pollution with an increasing range of ill health, including reduced intelligence, dementia and depression, while other works has revealed that air pollution can reach the brain.

«There seems to be some link between exposure to air pollution and effects in the brain and this is perhaps another example of this» said Prof Frank Kelly about the new research, at King’s College London and also part of the research team. «Children and young people are most vulnerable to the health impacts of air pollution owing to the juvenility of the brain and respiratory system». 

Stefan Reis, the head of atmospheric chemistry and effects at the Centre for Ecology & Hydrology said: «The study makes a valuable contribution to the growing body of evidence that air pollution may affect more than just cardiovascular and respiratory health, this new study makes a compelling case to investigate a range of mental health outcomes of air pollution exposure». 

Dr Ellen Wood, from the Doctors Against Diesel campaign group, said: «This study adds to the growing evidence that air pollution could have devastating and far reaching consequences on our physical and mental health, that is put at further risk if policymakers do not address this public health emergency». 

Finally, «we urgently need to see policies that equitably reduce polluting vehicles on our roads, and replace them with affordable, sustainable and accessible public transport» said Rebecca Daniels, at the global health charity Medact.