Winter air pollutants linked to stroke-related hospital admissions, research finds

File photo: John Giles/PA Wire

The research, led by a team from RCSI University of Medicine and Health Sciences, and published in the current edition of Cerebrovascular Diseases, looked at the effects of pollutants in Dublin and Cork.

Researchers analysed daily hospitalisation for all strokes and ischaemic stroke by residence in Dublin or Cork, combined with air pollution level monitoring data with a lag of between zero and two days from exposure.

The study focused on those two locations as the two largest metropolitan areas in Ireland and the highest density of air pollution monitoring sites.

Across the study period in the two centres there were 15,086 stroke cases, of which 10,830 were ischaemic strokes, the researchers said.

While the study found that there was no significant association between all stroke admission and any individual air pollutant, it did find that during winter in Dublin, there was an association between all stroke cases and various pollutants.

There was no significant association found in Cork, it found.

In Dublin during wintertime, higher levels of fine particles, coarse particles, sulphur dioxide and nitrogen dioxide were found in the air. 

The sources of these are solid fuel burning, such as coal, peat, and wood, as well as road traffic – especially diesel engines, the study found.

“Every year, more than 10,000 people in Ireland have a stroke. Our research adds evidence that there needs to be a national ban on solid fuel burning to help in our efforts to reduce this number,” said Dr Colm Byrne, the study’s lead author and clinical lecturer in the RCSI Department of Geriatric and Stroke Medicine.

There was no significant association for all air pollutants found in Cork, but there was a significant association between hospitalisations for strokes and higher levels of nitrogen dioxide and fine particles in the air.

“Because Ireland has relatively low air pollution when compared internationally, this highlights the need to introduce additional policy changes to reduce air pollution in all countries,” said Professor David Williams, professor of stroke medicine at RCSI.

In 2015, the Global Burden of Disease Study estimated that air pollution contributed to 6.5 million deaths globally.

Stroke and cardiovascular disease were increasingly recognised as major contributors to this morbidity and mortality, the RCSI authors said.

Climate Action Minister Eamon Ryan recently signed regulations to extend the smoky coal ban to all towns with populations over 10,000 people, including Carrigtwohill, Cobh, Midleton and Mallow.