The longer the fires burn, the more people are exposed to the harmful chemicals in the air that can trigger acute health problems, according to Northeastern researchers who study the effects of smoke inhalation.
More than a week after a series of wildfires broke out in and around Los Angeles, winds are starting to let up, giving firefighting crews the upper hand in containment efforts.
But the dangers are far from over. The longer the fires burn, the more people are exposed to the harmful chemicals in the air that can trigger acute health problems, according to Northeastern University researchers who study the effects of smoke inhalation.
“Based on the literature we have now, exposure and inhalation of fire smoke is positively associated with the number of hospital admissions or visits for different types of cardiovascular disease,” says Chiara Bellini, an associate professor of bioengineering at Northeastern. “Most of these visits occur within the first few days after the fire begins.”
The smoke created from wildfires contains toxic chemicals and particulate matter that can harm both firefighters and civilians in the area. The smoke can exacerbate pre-existing conditions, such as asthma and chronic obstructive pulmonary disease (COPD), but also lead to the development of other conditions later in life, says Jessica Oakes, a Northeastern associate professor of bioengineering.
“What’s worrisome about the L.A. fires is they include both housing materials as well as forest materials,” Oakes says. “The houses themselves have plastics, shingles and foams for the beds and the furniture, the cars have tires, and burning those materials can be very toxic to the respiratory and cardiovascular systems.”
Bellini and Oakes are studying the short-, medium- and long-term health effects of smoke inhalation on woodland firefighters — research that is funded by a $1.5 million grant from the Federal Emergency Management Agency.
The pair have been studying how the respiratory and cardiovascular systems in mice respond to smoke exposure over time. Specifically, they have focused on how the effects of smoke can accelerate aortic stiffening, a condition affecting the main artery of the heart, among other changes affecting blood vessels.
“The changes in the active and passive properties of the vasculature tell us that the continuous and repeated exposure to fire smoke carries cardiovascular risk,” Bellini says.
The human body is equipped to handle air pollutants — but only to a certain point. Mucus and tiny hair-like filaments in the upper respiratory system can help filter out harmful particles, and white blood cells deep in the lungs work to destroy debris associated with pollutants.
Researchers know that smoke exposure from wildfires causes acute — meaning short-term — damage to a person’s health by looking at hospitalization data. There is some evidence, Oakes says, that suggests that exposure can lead to changes in the respiratory system that evolve over time.
“So the work associated with breathing, or how hard it is to breathe, can change,” Oakes says.
Researchers are still trying to piece together exactly what those long-term effects are. There’s still lots unknown — even basic differences between fire smoke and cigarette smoke exposure remain unclear. There was a recent paper, Oakes says, that suggests that inhalation of fire smoke may be worse for our health than diesel exhaust or other sources of air pollution.
What kinds of chemicals and pollutants are found in the air during fires? Often there’s formaldehyde, polycyclic aromatic hydrocarbons, alcohols and carbon monoxide, among a whole host of others — all toxic and potentially carcinogenic, Oakes says.
Even after a fire is put out, many of these chemicals can persist in the air for quite some time, Bellini says.
“We are looking at months,” she says. “These particles from the smoke stay in the air for a long time.”
As more and more wildfires occur in drier regions of the U.S. and elsewhere, it’s important that people be aware of the risks not only to property and infrastructure, but to human health, the researchers say.
“The immediate challenge is always getting people evacuated and safe,” Oakes said this week. “But the long-term challenges — we don’t even have a great understanding of what those might be.”
What should you do to avoid the harmful effects of fire smoke?
If there is a fire burning in your area, Bellini recommends staying indoors, putting a filter in your HVAC system, and ensuring that your filter is clean. If you do go outside, be sure to wear a mask.
“When it comes to the particulate matter, the N95 is pretty good, especially if the fit around the nose and mouth is sufficiently tight,” Bellini says.