Air Pollution Linked To Increased Risk Of Stroke Interview with:
Dr Anoop Shah

Cardiology Research fellow
Centre of Cardiovascular sciences
University Of Edinburgh Edinburgh

Medical Research: What is the background for this study? What are the main findings?

Response: Stroke accounts for five million deaths each year and is a major cause of disability. The incidence of stroke is increasing, particularly in low and middle income countries, where two thirds of all strokes occur. The global burden of stroke related disability is therefore high and continues to rise. This has been primarily attributed to an aging population in high income countries and the accumulation of risk factors for stroke, such as smoking, hypertension, and obesity, in low and middle income countries. The impact of environmental factors on morbidity and mortality from stroke, however, might be important and is less certain.

From 103 studies and across 6.2 million fatal and non-fatal strokes, our findings suggest a strong association between short term exposure to both gaseous (except ozone) and particulate air pollution, and admissions to hospital for stroke or mortality from stroke. These associations were strongest in low and middle income countries, suggesting the need for policy changes to reduce personal exposure to air pollutants especially in highly polluted regions.

Medical Research: What should clinicians and patients take away from your report?

Response: Clinicians should realize that in addition to more traditional risk factors for stroke such as high blood pressure, environmental risk factors also play a significant role. However unlike traditional risk factors such diabetes or hypertension where only a fraction of the pollution are exposed, air pollution affects the whole population. If you work in somewhere like a factory, it may be a good idea to suggest oil mist elimination in your workplace as this can actually reduce pollution and improve workplace air quality. If this is something you’re interested in, check out Integrated Air Systems website here.

Medical Research: What recommendations do you have for future research as a result of this study?

Response: There are two areas of research that now need to take place. One to study effective measures that may reduce exposure to air pollution and how this may improve health in the future and two to understand the underlying mechanisms by which air pollution triggers stroke.


Short term exposure to air pollution and stroke: a systematic review and meta analysis

  1. Anoop S V Shah, clinical lecturer in cardiology,
  2. Kuan Ken Lee, core medical trainee,
  3. David A McAllister, senior lecturer in epidemiology,
  4. Amanda Hunter, specialist trainee in cardiology,
  5. Harish Nair, senior research fellow in epidemiology,
  6. William Whiteley, MRC clinician scientist and consultant neurologist,
  7. Jeremy P Langrish, clinical lecturer in cardiology,
  8. David E Newby, professor of cardiology,
  9. Nicholas L Mills, reader in cardiology and consultant cardiologist.

BMJ 2015; 350 doi: (Published 24 March 2015 Interview with: Dr Anoop Shah (2015). Air Pollution Linked To Increased Risk Of Stroke

Last Updated on March 26, 2015 by Marie Benz MD FAAD