Best Health Advice for Smoky Skies: Stay Inside and Wear a Mask When Outdoors

June 9, 2023 By Bryan McKenzie, bkm4s@virginia.edu Bryan McKenzie, bkm4s@virginia.edu

Smoke from more than 400 Canadian wildfires at least 1,000 miles away is wafting into Virginia, turning the Blue Ridge Mountains into a smoky landscape and decreasing visibility around the University of Virginia to less than 3 miles.

According to federal and state officials, the smoke is made up of carbon monoxide, carbon dioxide and particulate matter, or PM, but better known as soot.

Considering the wildfires are burning vegetation, buildings, vehicles and other things in their path, officials say the smoke can contain low levels of chemicals such as formaldehyde, sulfur dioxide, nitrogen oxide, polycyclic aromatic hydrocarbons, benzene, toluene, styrene, metals and dioxins.

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When you can see, smell and even taste the air you breathe, it is likely an indication the air is unhealthy. UVA Today checked with Dr. Kyle Enfield, a pulmonologist and medical director of the medical intensive care unit at UVA Health, to find out who is most at risk and how that risk can be limited.

Q. For whom is the current air quality situation most dangerous, and why?

A. Recently, we have seen air quality indices in Charlottesville between 150 and 200, peaking over 200 [on Thursday]. The air quality index (AQI) is a measure that puts together factors like ozone, nitrogen and sulfur dioxide levels, carbon monoxide, and particulate matter (PM 2.5). The major contributor to our poor air quality right now is PM 2.5.

When the AQI is above 150, many people will experience problems like coughing, watery eyes, and sneezing; however, those with chronic pulmonary conditions like asthma and COPD and those with heart conditions are at the most risk.

Canada wildfire smoke around Rotunda on Grounds
The gray sky that settled over Grounds and across the state resulted in poor air quality that could increase the risk of heart attacks, hospitalizations and strokes, according to a UVA Health expert. (Photo by Sanjay Suchak, University Communications)

For people with chronic conditions, an AQI of more than 100 increases the risk for health problems. Poor air quality adds additional strain to the body, and for those with chronic conditions, this strain can push someone from well to unwell.

Q. For people who do not have breathing or lung issues, is the smoke something that needs to be taken seriously?

A. Yes, we know that poor air quality increases hospitalizations and health care visits.

Q. According to the National Weather Service, the smoke has decreased visibility in some areas of the state to a mile or less, which means there’s a lot of smoke to breathe. What sort of things are in the smoke that could affect our immediate health?

A. The major component to both the poor visibility and health problems associated with wildfires is fine particulate matter, measured as PM 2.5. This is particles with aerodynamic diameters smaller than 2.5 micrometers. Because of their size, these particles deposit deep into the lung and lead to damage at the alveolar level, that is, the level where oxygen enters the blood and carbon dioxide leaves the lung.

Q. The wildfires have created conditions that have gone from what the National Oceanic and Atmospheric Administration ranked as “moderate” to “unhealthy” in just a few days. Officials say those conditions could linger for several more days as fires continue to burn. Are there possible long-term health impacts from the smoke?

A. Long-term exposure to high levels of PM 2.5 can impact human health, but more on the time scale of months to years of exposure, not days to weeks. That said, short-term exposure to poor air quality increases the risk of heart attacks, hospitalizations from respiratory illness, and strokes – and the personal impact of any of these can have lasting effects.

Q. What steps can people take to protect themselves from the adverse effects of the smoke?

A. First, we must recognize that it is hard to know when air quality will improve. The wildfires in Canada are ongoing and, as such, could impact our air quality for days and weeks to come; however, many things influence air quality, not just the production of particulate matter. This includes temperature, wind, and other atmospheric conditions.

Q. How about all those masks everyone already has from the pandemic?

A. Masks, like those we have all been using recently to protect ourselves from COVID, will help in this setting as well. The best masks remain N95 masks, as they will provide the greatest level of protection; however, surgical masks also help.

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Studies from the University of Colorado demonstrate that N95 provides the best protection. Surgical masks are good but because they allow for a significant amount of leak, their protection is limited. Staying inside with filtered air is also helpful, recognizing that the quality of the air in our houses is impacted by the outside air.  Replacing the air filters in your house can help with this by looking for a “MERV” – minimum efficiency reporting value – of 8 or higher.

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Bryan McKenzie

Assistant Editor, UVA Today Office of University Communications