Air pollution linked to severe mental illness: study
Exposure to air pollution is linked to an increased severity of mental illness, according to a new study published in the British Journal of Psychiatry.
The research, involving 13,000 people in London, found that a relatively small increase in exposure to nitrogen dioxide led to a 32% increase in the risk of needing treatment and an 18% increase in the risk of being admitted to hospital.
The researchers said the findings were likely to apply to most cities in developed nations.
"Air pollution is modifiable, and on a big scale as well, reducing population-level exposure," said Joanne Newbury, of the University of Bristol, part of the research team.
"We know there are interventions that can be used, such as expanding low-emission zones. Mental health interventions at the individual level are actually quite difficult."
The study used the frequency of admission to hospital or visits to community doctors and nurses as a measure of severity.
The researchers calculated that a small reduction in one pollutant alone could reduce illness and save the National Health Service tens of millions a year.
Levels of air pollution in London have fallen in recent years but there is no safe level, said Ioannis Bakolis, of King's College London, who led the research. "Even at low levels of air pollution, you can observe this kind of very important effect."
Recent research has shown that small increases in air pollution are linked to significant rises in depression and anxiety, reports The Guardian.
It has also linked dirty air to increased suicides and indicated that growing up in polluted places increases the risk of mental disorders.
Other research has found that air pollution causes a "huge" reduction in intelligence and is linked to dementia. A global review in 2019 concluded that air pollution may be damaging every organ in the human body.
The World Bank has estimated that air pollution costs the global economy $5tn a year.