A breath of fresh air: understanding the impact of air pollution on public health
This research, undertaken by Administrative Data Research Centre Northern Ireland (ADRC NI) researchers at Queen’s University Belfast, used Northern Ireland Longitudinal Study (NILS) and Enhanced Prescribing Database (EPD) data linked with air pollution data to assess the impact of outdoor air pollution on health.
The World Health Organisation (WHO) has identified outdoor air pollution as a top environmental risk factor for mortality and disease globally. In the United Kingdom, Public Health England has broadly estimated that between 28,000 and 36,000 deaths a year can be attributed to long-term air pollution exposure. In Northern Ireland (NI), improving both public health and air quality are two policy objectives set out in the NI Executive Programme for Government.
To understand the link between these two objectives in NI, and thus to understand how far reductions in air pollution might improve public health, this project used linked person-level data to investigate the impact of outdoor air pollution on several dimensions of health (from self-reported health at Census, to medication receipt, to risk of death) for a large representative sample of the population at various stages of the life course (from birth to death).
The dataset used in this study links NILS and EPD data with annual modelled 1x1 km grid square air pollution data published by the Department for Environment, Food and Rural Affairs. The health impacts of air pollution – including exposure over a 10-year period to fine particles such as PM 10 and PM 2.5, as well as gases such as Nitrogen Dioxide and Sulphur Dioxide, was assessed using statistical techniques.
The findings show that individuals with higher levels of pollution exposure between 2001 and 2010 are more likely than individuals with lower exposure to report adverse health outcomes at the 2011 Census. They are more likely to rate their general health as ‘bad’ or ‘very bad’; more likely to report a long-term illness which limits their day-to-day activities; and more likely to report suffering from long-term health conditions including breathing difficulties, memory loss, long-term pain, chronic illness, deafness, mobility difficulties, or a mental health condition. Work is ongoing to understand the links between pollution and prescription receipt and mortality.
The research team has presented research findings and discussed local air quality issues with charities and policymakers at the highest level. This has included a webinar organised by British Heart Foundation Northern Ireland and joint presentations with Asthma UK and British Lung Foundation (BLF).
Dr Neil Rowland and Elizabeth Nelson, Public Engagement and Impact Manager for ADRC NI, presented research findings to the All Party Group (APG) on Lung Health (alongside Asthma UK and BLF), engaging with attending Members of the Legislative Assembly (MLAs), health and community groups, and members of the public. Further follow-up with Paula Bradshaw MLA, chair of the APG, led to her submitting an Assembly Written Question regarding bridging legislation from the Digital Economy Act to allow the sharing and linkage of health data to other administrative data in Northern Ireland, which would support further data-driven research in this area.
The team also presented their work at a ministerial meeting (alongside Asthma UK and BLF) with Minister of Agriculture, Environment and Rural Affairs, Edwin Poots MLA, and key officials. Minister Poots asked detailed questions related to how the findings could shape the Clean Air Strategy and requested a further written and oral briefing from Dr Rowland when further findings were available, to further inform the strategy and action plan development.
The research team has also been developing an interactive air pollution map of Northern Ireland which will allow users to explore how levels of air pollution in their local area have changed through time. The dashboard will be showcased at the Economic and Social Research Council Festival of Social Science in November 2021 and is scheduled for public launch in autumn 2021.