DEP0001

Written evidence submitted by Mary Abed Al Ahad

(PhD student at University of St Andrews)

My name is Mary Abed Al Ahad and I am a 3rd year PhD student at the School of Geography and Sustainable Development, at the University of St Andrews, Scotland, UK. I am supervised by Professor Hill Kulu, Professor Frank Sullivan, and Dr. Urška Demšar. For the past three years, I have been researching on the association between long-term exposure to air pollution and multiple objective and self-reported health outcomes. I have also studied whether the association between air pollution and health is stronger for ethnic minorities and foreign-born individuals in the United Kingdom (UK). When I saw the call for evidence for “Defra Recall: Environmental protection”, I became interested in submitting evidence from my PhD research on the topic of air pollution and health in the UK.

In my PhD thesis, I linked yearly high-resolution spatial data on air pollution from DEFRA to individual-level longitudinal data from the 2011 UK micro-census, UK Household Longitudinal Study, and Scottish Longitudinal Data at different geographical scales including local authorities, census output areas, and postcodes of residence to study the association between long-term exposure to several air pollutants (e.g., Nitrogen Dioxide NO2, Sulphur Dioxide SO2, Carbon Monoxide CO, Particulate matter with diameter ≤ 10 µm PM10, Particulate matter with diameter ≤ 2.5 µm PM2.5, and Ozone O3) and various objective and self-reported health measures including general health, limiting long-term illness, mental well-being, mortality, and hospital admissions. My PhD thesis also investigated how the association between air pollution and health outcomes varies by ethnicity and country of birth in the UK.

Results showed that higher concentrations of NO2, SO2, CO, PM10, and PM2.5 air pollutants are associated with limiting long-term illness, poor self-reported health, lower ratings of mental well-being, and increased rates of mortality and hospital admissions. Particulate matter was mainly associated with all-causes, respiratory, cardiovascular, infectious and cancer mortality and hospital admissions, while SO2 was mainly related to mental/behavioural disorders/suicide mortality and respiratory hospital admissions. NO2 was associated with all mortality and hospital admission causes. The greatest impact was shown for PM2.5 pollution on respiratory mortality and hospital admissions. For example, the incidence rate of respiratory hospital admissions increased by 12% and the mortality hazard increased by 11% for every 1 μg/m3 increase in cumulative exposure to PM2.5 air pollutant.

Results also showed that ethnic minorities including Indians, Pakistani/Bangladeshi, and Black/African/Caribbeans and non-UK-born individuals tend to report poorer health with higher exposure to air pollution than the British-white and UK-born individuals. For example, people from an Indian, and Black/African/Caribbean origins were 50% more likely to report poor health with every 10 μg/m3 increase in PM10 pollutant compared to British-White individuals in the UK. However, differences by ethnicity were not noted in the association between air pollution and mental well-being.

In summary, my PhD thesis supports the presence of an association between air pollution and poor health outcomes, which is exacerbated for ethnic minorities and foreign-born individuals in the UK. The findings of this research contribute to the evidence needed by researchers and policymakers to take forward legislations related to air pollution and health and to address the ethnic inequalities in air pollution exposure and health. Introducing more strict measures on industries and encouraging the usage of renewable energy in transportation and energy production sectors can help in lowering the air pollution emissions. This would lead to better health and would ease the hospital-care and mortality burden not only for physical diseases but also for mental and behavioural illness.

March 2023

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