During the summer of 2023, residents of Baltimore watched their skies turn dark as smoke from massive Canadian wildfires drifted thousands of miles across the continent. Now, researchers have documented a stark reality: this distant smoke triggered a significant surge in heart and lung-related medical visits, highlighting how climate-driven disasters can impact human health across vast distances.Published in JAMA Network Open | Estimated reading time: 5 minutes
“Baltimore had very dark skies, and we could all smell the smoke in the air,” says Dr. Mary Maldarelli, a pulmonary critical care fellow at the University of Maryland School of Medicine and the study’s lead author. “But most importantly, my patients came in to me saying they were coughing quite a bit more and needed their medications more often, so they felt much sicker than they usually did when these wildfires occurred.”
The unprecedented 2023 Canadian wildfire season saw 6,551 fires destroy 18.5 million hectares of forested land. To understand the health impact of this distant disaster, researchers analyzed data from nearly 2 million de-identified patient records across the University of Maryland Medical System.
The research team identified six “hotspot” days in June 2023 when wildfire smoke dramatically degraded air quality across all 23 Maryland counties. During these periods, particulate matter pollution spiked to more than nine times normal levels in Baltimore City.
“We found that hotspot days were associated with an 18 percent increased likelihood of patients going to the doctor for complications related to a cardiopulmonary condition,” explains study corresponding author Dr. Bradley Maron, Professor of Medicine and Co-Executive Director of the University of Maryland Institute for Health Computing. “We also found a 55 percent increase in the risk for an outpatient visit for heart and lung conditions; these patients tended to be older, non-smokers, and more socio-economically affluent than typical patients who see their doctors for cardiovascular conditions on good air quality days.”
This socioeconomic disparity raises concerning questions about healthcare access. The researchers suggest that more economically disadvantaged patients may not be receiving the medical care they need during these high-risk periods.
Looking ahead, the research team emphasizes the need for proactive solutions. “We have the opportunity to leverage the capabilities of the UM-IHC to proactively identify patients who are most at risk and provide them with anticipatory care,” says Dr. Mark T. Gladwin, Dean of the University of Maryland School of Medicine. “There may be crucial ways we can prevent cardiovascular complications on polluted smoke air days simply by providing them with telehealth visits or other ways to access care.”
Glossary
- PM2.5
- Particulate matter with aerodynamic diameter smaller than 2.5 μm, a key measure of air pollution that can penetrate deep into the lungs.
- Hotspot Days
- Calendar days when air pollution levels exceeded the EPA’s National Ambient Air Quality Standard of 35 μg/m3.
- Area Deprivation Index (ADI)
- A measure of socioeconomic disadvantage in a given area, incorporating factors like income, education, employment, and housing quality.
Test Your Knowledge
How far did the Canadian wildfire smoke travel to reach Maryland?
The smoke traveled approximately 2,100 miles (3,400 km) from Western Canada to Maryland.
What percentage increase in medical visits was observed during hotspot days?
There was an 18 percent increase in the likelihood of patients seeking medical care for cardiopulmonary conditions during hotspot days.
What unique pattern emerged regarding patient demographics during smoke exposure?
Patients seeking care during hotspot days tended to be older, non-smokers, and more socio-economically affluent than typical cardiovascular patients on good air quality days.
What solution did researchers propose for future smoke events?
Researchers suggested leveraging telehealth visits and other alternative care access methods to help prevent cardiovascular complications during polluted air days, particularly for disadvantaged patients.
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