Long-term exposure to air pollution increases the risk of poor mental health in older adults

July 16, 2024

Health and Quality of Life
Energy and Environment
Social Inclusion and Equality
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Research published today (16 July) by the Economic and Social Research Institute (ESRI) and funded by the Environmental Protection Agency (EPA) finds that long-term exposure to air pollution is associated with poorer mental health in older people. One of the most damaging forms of air pollution is fine particulate matter (PM2.5), which in Ireland is caused mainly by the burning of solid fuels (coal, peat and wood) for heating. The research used data on the annual average level of fine particulate matter (PM2.5) over a 17-year period (1998-2014) linked to survey data from the Irish Longitudinal Study on Ageing (TILDA) to investigate the impact of PM2.5 on mental health. 

Key Findings:

  • Over the 17-year period 1998-2014, the average annual PM2.5 level for TILDA respondents was 7.7 μg/m3 (range 5-12), with over half the sample experiencing levels between 5 and 7 μg/m3. These levels were low by international standards (e.g., EU countries such as Poland and Bulgaria had annual average levels greater than 25 μg/m3 in 2014). However, they are above current World Health Organization (WHO) guideline levels - the WHO air quality guideline level for annual PM2.5 exposure is 5 μg/m3.
  • The statistical modelling showed that higher annual average PM2.5 levels were significantly associated with higher depression and anxiety.
  • No evidence of associations between long-term PM2.5 air pollution and other indicators of mental health and well-being (stress, worry and overall quality of life) was identified. It is possible that different dimensions of mental health may be influenced by the length of exposure or the specific type of pollutant.

Prof Anne Nolan, one of the authors of the paper noted ‘The study results add to the body of evidence that suggests that the health-damaging effects of air pollution can operate at low levels of exposure. In Ireland, the recent Clean Air Strategy commits to the achievement of the WHO air quality guidelines by 2040. Hitting this target will require substantial measures to decarbonise home heating, alongside measures to reduce pollution from industry, transport and agriculture.’

Dr Eimear Cotter, Director of the EPA Office of Evidence and Assessment, noted: “Our health and wellbeing are intrinsically linked to the quality of our environment. This research provides further evidence of that long-term exposure to air pollution, even at low levels, is damaging to health. The findings reinforce the need for policy measures to encourage the transition away from solid fuels towards alternative, less harmful forms of home heating.”