Americans are wondering how to protect themselves against smoke inhalation as over 93 million people across 18 states have been affected by pollution from Canadian wildfires, and many are wearing masks.

The Centers for Disease Control and Prevention on Thursday morning advised that properly wearing a respirator mask could be effective against the damaging health consequences of wildfire smoke, as an alternative to staying indoors.


Air pollution is responsible for 100,000 deaths in the United States per year, according to the National Weather Service.

Why is wildfire smoke dangerous?

Although the physical destruction and material cost of fighting wildfires is obvious, the health effects of wildfire smoke are less apparent but also deleterious — and pervasive.

Wildfire smoke consists of toxic air pollutants, such as carbon monoxide, and particulate matter, or dust, soot, ash, and other various chemicals. Particulate matter makes up at least 80% of wildfire smoke.

“[T]he same harmful particulate matter and gasses that are in tobacco smoke are in wildfire smoke,” explained Dr. John Balmes, a pulmonologist at the University of California Berkeley School of Public Health, in an interview with the Washington Examiner.

Dr. Mary Prunicki, director of air pollution and health research at the Sean N. Parker Center for Allergy and Asthma Research at Stanford University, told the Washington Examiner that anyone can experience serious health consequences from exposure to wildfire smoke.

"After a wildfire, you’ll see increases in emergency room visits and hospitalizations for respiratory events — things like asthma exacerbation, COPD exacerbation, or bronchitis and pneumonia. You see that in the very young — up to age five — as well as the elderly, and anybody with a preexisting condition,” Prunicki said.

What are the highest risk factors for complications?

Roughly 83 million Americans suffer from a condition that would put them at a greater risk of developing more severe complications from smoke exposure, putting them in the “sensitive group,” according to Environmental Protection Agency and National Oceanic and Atmospheric Administration standards.

An estimated 25 million people have asthma, and 12.5 million have COPD, chronic conditions that make breathing difficult even during periods of good air quality.

Diabetes is also a comorbidity for adverse health outcomes during episodes of diminished air quality. Nearly 29 million Americans have been diagnosed with diabetes, and 96 million have been diagnosed with pre-diabetes based on blood glucose readings.

Pregnant women are also at severe risk of developing birth complications due to wildfire smoke. A 2021 study found that women who have not built up a tolerance to recurrent air pollution are more likely to experience premature birth and low birth weights.

“Very pregnant women are one of the vulnerable populations, just like the elderly, the very young, those with preexisting conditions, homeless people — those groups that really need to pay more attention to exposure to the smoke,” Prunicki said.

Do masks work against wildfire smoke?

If staying indoors is not an option, the EPA and CDC recommend wearing an N95 or P100 respirator mask to filter out the particulate matter that makes wildfire smoke especially toxic.

N95 respirators have been found to have a 95% filtration efficacy for particles of 0.1-0.3 microns. A micron is one-millionth of a meter, or about one-sixth the size of a red blood cell.

Although there remains significant controversy as to the effectiveness of N95 masks against the SARS-CoV–2 virus, ranging from 0.07-0.09 microns, particulate matter from wildfire smoke is significantly larger.

The EPA identifies that the majority of the toxins in wildfire smoke are fine particulate matter, which ranges from 0.1-2.5 microns. There are also trace elements of coarse particulate matter in wildfire smoke, which can be up to 10 microns in size.

“Cloth (wet or dry), paper masks, and tissues will NOT filter out wildfire smoke,” says the EPA.

Are there other public health recommendations?

The CDC and EPA recommend staying indoors or evacuating affected areas if possible.

“Use a respirator only after first trying other, more effective methods to avoid smoke. That includes staying indoors and reducing activity," according to the EPA.


Outdoor exercise during dangerous air quality conditions should also be avoided.

“The worst thing to do is to go exercise like running or biking when the air quality is bad, because that increases your dose of exposure to the wildfire smoke. People often start breathing through the mouth and bypass the filtering mechanism of the nose,” Balmes said.

Tags: Wildfire, Healthcare, Smoking, Environment, EPA, CDC

Original Author: Gabrielle M. Etzel, Breanne Deppisch

Original Location: Wildfire smoke: Masks making a return over respiratory harm fears — what to know

2023-06-08T18:14:16Z dg43tfdfdgfd