U.S. study links Canadian wildfire smoke to doctor visit spike in Baltimore

Raging Canadian wildfires that choked North America under clouds of smoke last year may have contributed to a spike in doctor visits for lung and heart problems thousands of kilometres away.

U.S. researchers published peer-reviewed findings Friday that suggest doctor visits in the Baltimore area for heart and lung problems increased by almost 20 per cent on six "hotspot" days linked to wildfire smoke from Western Canada.

Canada's worst wildfire season on record saw plumes of smoke drift across the continent made up of fine-particle pollution that's tiny enough to get deep in the lungs and create serious health effects.

Researchers at the University of Maryland identified six days in June 2023 when wildfire smoke-related pollution was the highest and compared it with anonymized patient records, including hospital admissions and visits to the ER and outpatient clinics.

The study says those hotspot days were associated with an 18 per cent higher likelihood that patients visited the doctor for a cardiopulmonary condition, compared to the volume of visits on days in June 2018 and June 2019.

Researchers say in the study published by Jama Network Open that patients tended to be more affluent overall than those who made visits on days with good air quality, suggesting disadvantaged patients may not be getting the care they need on high-risk days.