Air pollution research and stroke

Long-term exposure to high levels of outdoor air pollution has been linked with poor health in many cities around the world.

Using information from the South London Stroke Register (SLSR), a team including researchers from King’s College London wanted to find out if people who had a stroke were affected by higher levels of outdoor air pollution. They looked at the health of 1800 people who had a stroke between 2005-2012.

The researchers found that those living in areas with lower levels of particulate matter live longer after a stroke. Particulate matter is a type of air pollutant made up of tiny bits of matter floating in the air from natural sources such as dust and pollen as well as man-made sources like soot, smoke and car exhausts.

SLSR researchers and air pollution scientists from King’s College London are doing more research to find out how particulate matter causes poor health effects in people.

The article, published in the journal Stroke, requires a subscription or payment to view:


3 thoughts on “Air pollution research and stroke

  1. The article is behind a paywall.

    In this (and other) blog posts, you do not explicitly compare the outcome for people who have had strokes with an identified control group, so it is impossible for the reader to assess the significance of the findings. Please will you do this in future (and, ideally, add the control group description, the comparison and the statistical significance to the existing blog entries too)?


  2. Thanks for your comment. For this blog, we ask researchers to provide a lay-friendly summary of their study, as lay people (such as participants in the South London Stroke Register) are the primary intended readership. For that reason we have not included technical details of the methodologies, statistical significance and so on. It is unfortunate that this article is paywalled and I will update the blog post to state this.

    I hope the following information from the article will be of use:

    This particular study was a survival analysis of South London Stroke Register participants, linked with an air pollution exposure model. It did not use a control group but compared the survival of register participants with different levels of exposure to air pollution. Models controlled for the following confounders: age, sex, ethnicity, year of stroke, deprivation (Index of Multiple Deprivation rank subdivided into quarters), transient ischemic attacks before stroke, and stroke severity (National Institutes of Health Stroke Scale total). The hazard of death associated with particulate matter less than 2.5 micrometres in diameter up to 5 years after stroke was significantly elevated (P=0.006) for all strokes (hazard ratio [HR]=1.28; 95% confidence interval [CI], 1.08–1.53) and ischemic strokes (HR, 1.32; 95% CI, 1.08–1.62).

    For further information about this study, please contact the lead author anita.desikan AT


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