Acute mental illness linked to pollution?

Researchers from the University of St. Andrews used sixteen years of data taken between 2002 and 2017 from Public Health Scotland of more than 200,000 adults to track those attending hospital for depression, anxiety and psychosis as well as respiratory disease.

Their findings revealed that air pollution levels affected their chances of being sent to hospital. For every additional microgram of nitrogen dioxide (NO2) in the air, the participants were 2.1% more likely to be taken to hospital for a mental illness.

Nitrogen dioxide emissions principally emanate from vehicle exhausts but also from gas fired power stations and boilers. Fluctuations in pollution levels were observed across the study period with the highest levels recorded between 2002 and 2004. Average annual levels for nitrogen dioxide were lower than the 2005 World Health Organisation  guidelines but higher than the 2021 guidelines.

Air pollution has long been known to cause physical illnesses to include a range of cardiovascular and respiratory illnesses but its effect on mental illness is less well documented.

The research was published in the British Medical Journal (BMJ Open access). The lead researcher Dr Mary Al Ahad (University of St. Andrews) said ”Policies and interventions targeting air pollution emissions such as zero-emission zones or incentives for renewable energy in transportation and energy producing sectors would ease the hospital-care burden in the long-term both locally and globally”.

Peter Ward