New Study Suggests Short-Term Exposure to Pollution Increases the Risk of Stroke

Pollution has been linked to all kinds of illnesses – from respiratory infections to reduced lung activity in infants – but a recent study conducted at The University of Edinburgh and published in the British Medical Journal indicates that exposure to outdoor pollution can also trigger an increased risk of stroke.

The findings published in a report last month suggest that even short-term exposure to pollution can have an adverse effect on health, and this risk was higher in low to middle income countries. When put in perspective, this means the health of 1.6 billion people could be at risk as a result of poor air quality in urban areas.

The link between air pollution and strokes

The study found a direct link between spikes in the level of air pollution, and spikes in the number of people admitted to hospital for stokes. The study also revealed the correlation was more apparent in low-income countries, such as China. Lead author of the study, Dr Anoop Shah said: "This study now demonstrates that even short-term exposure to air pollution can trigger disabling strokes or death from stroke.” 

While it was previously thought that only the vulnerable were at risk, this study revealed that an increase in exposure to pollution puts everyone at increased risk of stroke or cardiovascular events – not just the elderly and the very young. Likewise, it was previously thought that only long-term exposure to pollution would cause stroke, but this study suggest this isn’t the case, and even short-term exposure can have significant impact.

The major components of air pollution are nitrogen dioxide, ozone, and suspended solid or liquid particles. While exposure to these elements might not directly cause strokes, it is suggested that exposure to these particles can cause an increase in blood pressure and constrict the blood vessels.

For more information about air pollution in the UK, read this article: Improving Air Quality and Reducing Transport Related Pollution.

Air Quality in the UK

This information is particularly pertinent for people in the UK, where 40 out of the 43 zones used to measure air pollution have been found to exceed EU limits. New targets were set after Britain failed to meet the 2010 targets, but the government has admitted that some areas won’t be within target until 2020, or as late as 2025.

London, Manchester and Merseyside have all been identified as problem areas – and diesel engines are the worst offender. Some streets in London have recorded pollution levels at four times the legal limit, which puts people in those areas at increased risk of a multitude of health problems. The British Heart Foundation, which funded the study, has suggested that urgent action needs to be taken to cut the amount of pollution in the UK’s skies. It also suggests those with existing heart conditions should monitor pollution levels where they live and work and try to limit exposure.

Spanish study on pupils and air pollution

In Spain, a year-long study tested 2,715 children across 39 schools for memory and attentiveness. The study revealed that children who attended schools with good air quality tended to fare better than their peers in more polluted areas. For more information on this topic, read: Does Pollution Affect Intelligence?