Car pollution increases the rate of psychotic episodes and worsens mental illness, a groundbreaking study suggests.

The first research ever to investigate the link between psychotic experiences and poor air quality found teenagers living in areas of high pollution suffered more than those in cleaner environments.

The researchers, from King's College London, used data from 2,232 children born in England and Wales.

They found that, overall, approximately a third of adolescents reported hearing or seeing something that wasn’t there, or feeling paranoid on at least one occasion between the ages of 12 and 18.

Such episodes, while not necessarily serious in themselves, can be a gateway to graver mental conditions such as schizophrenia.

The mental health data was compared against with hourly estimates of air pollution at their home addresses and two other locations where they spent a lot of time at the age of 17 such as a school.

"This study found that psychotic experiences were significantly more common among teens exposed to higher levels of air pollution," lead author Dr Joanne Newbury said.

"For example, teenagers exposed to the highest levels of nitrogen oxides had a 72 per cent greater odds for psychotic experiences compared to those with lower exposure.”