How much smoke exposure is enough to trigger an asthmatic attack or cardiac arrest?

Date posted: 
Tuesday, January 17, 2017

As the global climate changes we are seeing more intense and frequent forest fires in British Columbia. Forest fires cause some of the worst air pollution that many Canadians will ever experience, and smoke affects everyone in exposed communities.

There is clear evidence that exposure to forest fire smoke affects all measures of respiratory health in large populations, including use of medications, outpatient physician visits, emergency room visits, hospital admissions, and mortality. There is also emerging evidence that smoke is similarly associated with cardiovascular outcomes.

“All of this evidence has been generated using smoke measurements that are averaged over 24-hour periods, so the time scale of the effects remains unclear,” says Jiayun Yao, a PhD student in the School of Population and Public Health at the University of British Columbia. “At this time we simply do not know whether a community exposed to a few hours of smoke is at risk of experiencing significant increases in adverse health outcomes, and nor do we know whether communities that are smoked in for days or weeks are at higher risk during periods of peak exposure.”

Yao hopes to address these questions in her thesis project, funded by the British Columbia Lung Association. The study will investigate the potential health effects of sub-daily exposure to forest fire smoke by developing a model to produce hourly maps of smoke-related fine particulate matter concentrations, and assessing their relationship with ambulance dispatch data from across British Columbia. Study results will address two gaps related to forest fire smoke and public health: the health risks associated with transient exposures that last for less than one day; and the health risks associated with peak exposures within smoky days.

“If one hour of smoke exposure is enough to trigger an asthmatic attack or a cardiac arrest, we need to know so that we can improve public health policies, such as when to issue air quality advisories, to help populations to prepare for fire seasons that are getting more intense as the global climate changes,” says Yao.

For the project, PopData will link BC Ministry of Health data with data from BC Ambulance Service and researcher-collected exposure model estimates.

Page last revised: January 17, 2017