Scots living in areas with polluted air are at greater risk of hospital admission for mental health as well as physical illness, according to new research. Scientists at the University of St Andrews linked cumulative exposure to air pollution to an increased chance of hospitalisation for both mental and physical conditions, including heart and lung problems and mental illness or behaviour disorders.
Previous research has focused on deaths rather than hospital admissions, and on physical health rather than mental health. Now, new data analysis has examined four key pollutants between 2002 and 2017 and the impact of “ambient” air pollution.
The study looked at Public Health Scotland data on 202,237 adults and compared this to levels of four key air pollutants where they lived between 2002 and 2017. The pollutants from road traffic and industry were nitrogen dioxide (NO2); sulphur dioxide (SO2); particulate matter diameter of at least 10 microns (PM10) and small particulate matter of 2.5 microns or less (PM2.5).
Hospital admissions for cardiovascular, respiratory, or infectious diseases and mental illness/behaviour disorders were tracked – with cumulative exposure to air pollution strongly associated with higher rates of hospitalisations. Higher cumulative exposure to NO2, PM10, and PM2.5 was associated with a higher incidence of hospital admissions for all causes.
Sulphur dioxide was mainly associated with hospital admissions for respiratory disease while nitrogen dioxide was associated with a higher number of admissions for mental illness or behavioural disorders.
Dr Mary Abed Al Ahad, from St Andrews Uni, led the data review on the health effects of long term exposure, and concluded stricter environmental restrictions are needed to curb the impact on secondary care. She said: “Policies and interventions targeting air pollution emissions such as zero-emission zones or incentives for renewable energy in transportation and energy production sectors could help ease the hospital-care burden in the long-term both locally and globally.”
Researchers drew on individual level data from the Scottish Longitudinal Study, which represents 5 per cent of the Scottish population and includes demographic information from linked censuses. In all, 202,237 people aged 17 and above were included in the research which was published in the open access journal BMJ Open using data from 16 years.
Exposure to ambient air pollution was assessed yearly rather than monthly or daily, so masking seasonal variations, while people’s personal exposure to air pollution was worked out based on their residential postcode.
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