Study finds that short-term exposure to smoke from 2016 Fort McMurray wildfires in Alberta affected lung function

Equipment more sensitive than a conventional spirometer was able to detect lung damage

Horse River Fire Alberta, Canada 2016
A police officer walks past burned homes in Fort McMurray, Alberta, Canada May 5, 2016. AFP photo / Alberta RCMP / HO

A study on the health of Royal Canadian Mounted Police (RCMP) officers who were deployed in Alberta, Canada in 2016 to the Horse River Fire at Fort McMurray found that their airway function was compromised in the first three months after deployment. An analysis of health data from 218 officers revealed that the small airways in their lungs underwent structural changes after they were deployed, potentially increasing their risk for respiratory diseases in the future. The median exposure duration of the officers was eight days.

“We cannot tell from our study whether it’s long-lasting damage, but we do know from other studies that if people are exposed to high levels of particulate matter in the air, they are more likely to suffer from long-lasting damage to the lungs,” said Paige Lacy, professor of medicine at the University of Alberta and former director of research for the Alberta Respiratory Centre.

The Horse River Fire caused the largest evacuation in Canadian history, with more than 80,000 people rapidly removed from the community as fires encroached on the city. Hundreds of RCMP members were sent to the community to assist with the evacuation and to secure the area in the following days. The fire burned 589,552 hectares (1.4 million acres) in 2016 and destroyed 2,400 structures. The extreme fire behavior created lightning in the pyrocumulonimbus cloud atop the smoke column that started a number of new wildfires 40 kilometers (26 miles) ahead of the main wildfire front according to a report released in June of 2017.

Horse River Fire Alberta
These two fires started at about the same time on May 1, 2016 near Fort McMurray, Alberta, Canada. On the left is the MMD-004 fire inside the city limits of Fort McMurray. The Horse River Fire, often referred to as the Fort McMurray Fire, is on the right.

Subtle changes in lung function detected
The lung-function data were gathered as part of a larger study being conducted by Synergy Respiratory and Cardiac Care, looking at the health of RCMP officers dispatched to the Fort McMurray wildfire. According to the researchers, the subtle differences in lung function that were found were not measurable using traditional lung-function tests, and could only be observed through the use of more sensitive instruments. Researchers employed both spirometry and body plethysmography testing methods.

“Small airways are potentially more vulnerable and there is no way that a spirometer (a device commonly used to measure lung function) can detect the progression of their damage over time,” said Subhabrata Moitra, first author on the study and a post-doctoral fellow in the U of A’s Division of Pulmonary Medicine. “So if we use highly sensitive instruments, we can immediately get some signals whether there are any acute yet subtle changes caused by physiological factors or occupational or environmental hazards.”

The researchers noted that because the officers only came in for testing once after being deployed, they were not able to observe potential recovery of lung function or measure long-term damage.

The authors of the study pointed out the importance of having a health-surveillance program in place so responders who are exposed to such hazards can have their health monitored.

Survey finds that firefighters also complained of respiratory issues
A survey found that some firefighters who fought the fire at Fort McMurray also battled respiratory and mental health issues.

Below is an excerpt from a 2017 CBC news article:

The University of Alberta study surveyed 355 firefighters and found a “very large proportion” of them complained of respiratory issues including coughing, breathlessness, wheezing and chest tightness in the immediate aftermath of the fire.

“When we saw them later, probably about one in five of those still had problems with their chests that they felt had been caused or made worse by the fire,” said Nicola Cherry, the epidemiologist leading the study.

And they’re battling more than just physical ailments — mental-health issues affect one in six of study participants.

“When we collected this information, it was early days and people may develop bigger issues as time goes forward,” Cherry said.

Our Take
It is likely that wildland firefighters are routinely exposed to far higher concentrations of smoke and for longer periods of time than the RCMP officers at Fort McMurray. It is important that agencies who employ wildland firefighters establish a health-surveillance program that includes lung function tests using methods such as body plethysmography that are much more sensitive than a conventional spirometer.

Researchers find that wildfire smoke poses neurological hazards

Inhaled microscopic particles from wood smoke can work their way into the bloodstream and reach the brain, putting people at risk for premature aging and various forms of dementia, depression, and even psychosis

Satellite photo, smoke from California fires
Satellite photo, smoke from California fires at 7:01 p.m. PDT Aug 4, 2021.

The research outlined below by the University of New Mexico Health Sciences Center is further evidence of the importance of smoke management. Land managers, agency administrators, and incident management teams need to constantly consider methods of reducing smoke exposure to firefighters and the downwind population when planning, conducting, or suppressing wildfires and prescribed burns.

Woodsmoke from massive wildfires burning in California shrouded much of the West last summer, making it harder for people suffering from respiratory illnesses to breathe.

Those respiratory consequences can be dangerous — even life-threatening — but Matthew Campen, PhD, a professor in The University of New Mexico College of Pharmacy, sees another hazard hidden in the smoke.

In research published online this week in the journal Toxicological Sciences, Campen and his colleagues report that inhaled microscopic particles from woodsmoke work their way into the bloodstream and reach the brain, and may put people at risk for neurological problems ranging from premature aging and various forms of dementia to depression and even psychosis.

“These are fires that are coming through small towns and they’re burning up cars and houses,” Campen says. Microplastics and metallic particles of iron, aluminum and magnesium are lofted into the sky, sometimes traveling thousands of miles.

In the research study conducted last year at Laguna Pueblo, 41 miles west of Albuquerque and roughly 600 miles from the source of wildland fires, Campen and his team found that mice exposed to smoke-laden air for nearly three weeks under closely monitored conditions showed age-related changes in their brain tissue.

The findings highlight the hidden dangers of woodsmoke that might not be dense enough to trigger respiratory symptoms, Campen says.

As smoke rises higher in the atmosphere heavier particles fall out, he says. “It’s only these really small ultra-fine particles that travel a thousand miles to where we are. They’re more dangerous because the small particles get deeper into your lung and your lung has a harder time removing them as a result.”

When the particles burrow into lung tissue, it triggers the release of inflammatory immune molecules into the bloodstream, which carries them into the brain, where they start to degrade the blood-brain barrier, Campen says. That causes the brain’s own immune protection to kick in.

“It looks like there’s a breakdown of the blood-brain barrier that’s mild, but it still triggers a response from the protective cells in the brain — astrocytes and microglia — to sheathe it off and protect the rest of the brain from the factors in the blood,” he says.

“Normally the microglia are supposed to be doing other things, like helping with learning and memory,” Campen adds. The researchers found neurons showed metabolic changes suggesting that wildfire smoke exposure may add to the burden of aging-related impairments.

The research team included colleagues from the College of Pharmacy and the UNM Departments of Neurosciences, Geography & Environmental Studies, and Earth and Planetary Sciences, as well as researchers at Arizona State University, Michigan State University and Virginia Commonwealth University.

Story provided by University of New Mexico Health Sciences Center. Original written by Michael Haederle.

Journal Reference:

David Scieszka, Russell Hunter, Jessica Begay, Marsha Bitsui, Yan Lin, Joseph Galewsky, Masako Morishita, Zachary Klaver, James Wagner, Jack R Harkema, Guy Herbert, Selita Lucas, Charlotte McVeigh, Alicia Bolt, Barry Bleske, Christopher G Canal, Ekaterina Mostovenko, Andrew K Ottens, Haiwei Gu, Matthew J Campen, Shahani Noor. Neuroinflammatory and neurometabolomic consequences from inhaled wildfire smoke-derived particulate matter in the Western United States. Toxicological Sciences, 2021; DOI: 10.1093/toxsci/kfab147

Thanks and a tip of the hat go out to Gerald.

This time of the year can be a challenge for wildland firefighters

Six hotshot crews
Six hotshot crews: Los Padres, Horseshoe, Fulton, Springville, Breckenridge & Kern Valley

The holidays at the end of the year can be tough for many people, including wildland firefighters. With that in mind we are re-running this article from a few months ago.

Wildland firefighters on crews that are often deployed on endless 14-day assignments far from home may become acclimated to the high energy adrenaline-fueled environment. They are part of a team working toward the same clear objective, constructing fireline, installing hose lays, or mopping up. The goal is usually very obvious, and when done they can look back and see what they accomplished while part of a group that over months together could complete each other’s sentences. They know what each would do when faced with a pulse-elevating situation, or how they deal with boredom while waiting for a ride back to fire camp.

When the fire season is over, their environment goes through a metamorphose. Almost overnight they may find themselves with their spouse, significant other, children, parents, non-fire friends, or, alone — a completely different situation from the previous six months. Some firefighters adapt more easily than others. Those that don’t, may experience mental health issues and mild or severe depression. Spouses or children of the often-absent firefighter may also show symptoms.

In the last five years we have learned that the suicide rates of wildland firefighters is “astronomical”, according to information developed by Nelda St. Clair of the Bureau of Land Management in 2017. It is high even when compared with structural firefighters, which is also higher than the general population.

As we approach the slower part of the fire year, especially for those who are employed less than full time, if you know someone who seems very depressed, it is OK to ask them if they are thinking about suicide. Some people think this will spur suicide attempts but that is not accurate. Encouraging them to talk could be the first step leading them to safety.

This video encourages that communication. (I’m told that some of the people in the video are YouTubers. It features Hannah Hart, Liza Koshy, Markiplier, Meredith Foster, Orion Carloto, Remi Cruz, Shannon Beveridge, Tyler Oakley, and Tyler Posey.)

Members of the military returning from deployment can also have difficulties readjusting to life back at home. A Department of Defense webpage has information on the subject that appears to be directed toward the spouse. Here is an excerpt.

Depression and Suicide Prevention
Depression can happen to anyone – resulting in long-term feelings that affect an individual’s mood and daily activities. Service members may be facing challenges during reintegration that seem completely overwhelming, but understanding the warning signs for depression and suicide can help you intervene and get the them the help that they need. Signs to be aware of include:

–A range of emotions and changes in personality, including repeated and intense feelings of sadness, anxiety, hopelessness or pessimism
–A loss of interest in life or hobbies and prolonged periods of crying or sleeping
–Substance abuse or withdrawal from friends and family
–Displays of emotional distress in online activity
–Excessive feelings of guilt, shame or a sense of failure
–Physical symptoms like weight loss or weight gain, decreased energy, headaches, digestive issues or back pain
–Talking about dying or seeking information about death.


Help is available for those feeling really depressed or suicidal.

NWCG restores previously removed video about firefighter mental health

Check it out before it is shut down again

Lone firefighter in smoke
Image from the “Wildland Firefighter Mental health” video.

Three months after it was removed from YouTube, today the National Wildfire Coordinating Group restored a video about mental health for firefighters. Previously it had been available for two months but not publicized. We learned about it on September 29, 2021 when @DOIWildlandFire encouraged people on Twitter to view it. Seeing that it was an excellent video that could potentially help thousands of emergency management personnel, we embedded it right away on Wildfire Today. Within 24 hours it was removed from YouTube, because, as @NWCG explained, it was “accidentally posted” and was not “finalized.”

Here is what we wrote on Sept. 29:

The National Wildfire Coordinating Group has published a video for firefighters about mental health. It features several former or current firefighters who have been trained as critical incident stress management peer supporters or CISM Clinicians.

@DOIWildlandFire tweeted about the video today, encouraging everyone to view it. The video was posted July 19, 2021 but as of today it has only been viewed 83 times, perhaps because it is “unlisted”.  We suggested to them that the status be changed, which should make it possible to search for it and also show up on lists of NWCG videos.

The presenters make an interesting point comparing physical fitness and mental fitness. As a firefighter you have to work at both of them, and they lay out several ways to stay mentally fit.

If you are a firefighter or the spouse or family member of one, spend 18 minutes watching this video.

It really is a very good video. Check it out before it is removed again. It’s below.

Processing the trauma of a near miss

Dozens of firefighters had a very close call on the Route Fire

Fire crews on the Route Fire entrapped
Fire crews on the Route Fire, 4:40 p.m. Sept. 11, 2021, five minutes before they were nearly entrapped. Photo by one of the firefighters.

Many of the firefighters on the Route Fire who escaped from what was close to becoming a mass casualty incident on September 11, 2021 no doubt had stress levels that were very high as it was happening, and possibly for days, weeks, or months later.

As we covered in an article on December 11, dozens of firefighters on the fire north of Los Angeles suddenly found themselves on a road with fire on all sides of them. Even though it occurred three months ago the story had not been publicly told, until yesterday. As flames closed in on them, a Captain on a US Forest Service engine took charge and organized an effort for 13 firefighters on foot with no access to their regular transportation, to take refuge in two USFS Type 3 engines, each already carrying their normal complement of 5 firefighters. Almost unbelievably, 7 crammed into one engine and 6 got in another. There were a total of 23 bodies in the two engines. Then with flames on both sides of the road, they drove through smoke to safety. Two firefighters were treated in a hospital burn unit and released.

It could have been much worse. One person thought he was going to die.

“The more experienced firefighters were more shaken up than the new guys,” a firefighter told Wildfire Today. “Firefighters on the outside looking in were pretty shaken up, but as best as I can tell I think we are all doing good.”

One person said that as they were becoming entrapped and during the escape from the nearby flames he realized later that he does not have a complete memory of the event, “My memory blacked out from time to time…It’s psychology I don’t fully understand.”

Today I found a reference by Mike Degrosky to an article in the Harvard Business Review written by Diane Musho Hamilton that might shed some light on the topic. Interestingly, at the top of the article is an old photo of a P3 air tanker dropping retardant, even though the word “fire” is not mentioned anywhere in the piece. It starts with describing the two amygdala in the brain which were characterized by Dr. Bessel Van Der Kolk, in his book The Body Keeps the Score, as the brain’s “smoke detector.” (Which may be the genesis for the photo of the air tanker.) The amygdala’s job is to detect fear and help the body prepare for an emergency response.

Here is an excerpt:

“…When we perceive a threat, the amygdala sounds an alarm, releasing a cascade of chemicals in the body. Stress hormones like adrenaline and cortisol flood our system, immediately preparing us for fight or flight. When this deeply instinctive function takes over, we call it what Daniel Goleman coined in Emotional Intelligence as “amygdala hijack.” In common psychological parlance we say, “We’ve been triggered.” We notice immediate changes like an increased heart rate or sweaty palms. Our breathing becomes more shallow and rapid as we take in more oxygen, preparing to bolt if we have to.

“The flood of stress hormones create other sensations like a quivering in our solar plexus, limbs, or our voice. We may notice heat flush our face, our throat constrict, or the back of our neck tighten and jaw set. We are in the grip of a highly efficient, but prehistoric set of physiological responses. These sensations are not exactly pleasant — they’re not meant for relaxation. They’re designed to move us to action.

“The active amygdala also immediately shuts down the neural pathway to our prefrontal cortex so we can become disoriented in a heated conversation. Complex decision-making disappears, as does our access to multiple perspectives. As our attention narrows, we find ourselves trapped in the one perspective that makes us feel the most safe: “I’m right and you’re wrong,” even though we ordinarily see more perspectives.

“And if that wasn’t enough, our memory becomes untrustworthy. Have you ever been in a fight with your partner or friend, and you literally can’t remember a positive thing about them? It’s as though the brain drops the memory function altogether in an effort to survive the threat. When our memory is compromised like this, we can’t recall something from the past that might help us calm down. In fact, we can’t remember much of anything. Instead, we’re simply filled with the flashing red light of the amygdala indicating “Danger, react. Danger, protect. Danger, attack.”

“In the throes of amygdala hijack, we can’t choose how we want to react because the old protective mechanism in the nervous system does it for us — even before we glimpse that there could be a choice.  It is ridiculous.”

The first large fire I was on, with El Cariso Hotshots, we had a near miss in Washington state, and had to escape uphill. It was a long, steep, hike out of a canyon with spot fires igniting around us. At the time I was not too concerned, in part because our Superintendent, Ron Campbell, seemed calm, as did the more experienced crew members. I was a sawyer and when another firefighter asked if I needed relief carrying the saw, I was too proud to give it up, and kept it. If I had known the true gravity of our situation I probably would have accepted his offer. As a rookie, I did not appreciate at the time how dangerous the incident was.

Five years later our Laguna Hotshot crew was directed to walk downhill on a partially completed fireline and extend it further. Two other crews were ahead of us. We only got a fairly short distance down the line when all of us were ordered out. We hiked back up to safety with no problem and later the fire ran uphill. After five years on a hotshot crew I didn’t really think too much about it, since to me it did not fall into the near miss category. It can be fairly routine to pull back when it becomes obvious nothing worthwhile can be accomplished or that it can become unsafe. However several days later after we had returned from the fire, one of the rookies quit, citing the event as the reason.

It can be impossible to predict how rookies or experienced firefighters will react to a terrifying narrow escape. It might be life-altering in a negative way, or something that is dealt with, and put away in the “slide file” of experiences to help make better, more informed decisions down the road.

I hope the firefighters on the Route Fire who were nearly entrapped, and those who witnessed it through smoke from a distance, are able to receive counseling if needed and can process what happened September 11, 2021. It’s the kind of traumatic event that can stick with a person and everyone is impacted differently.

As Sgt. Phil Esterhaus used to tell his Hill Street Blues cops as they left the briefing to begin their shift, “Hey. Let’s be careful out there.”

Victoria’s parliament passes presumptive rights compensation for wildland firefighters

Wildland firefighters are at high risk for cardiovascular disease, lung cancer, and other conditions

6:48 a.m. PDT Nov. 3, 2021

firefighters Dixie Fire
Firefighters near the site of a venting propane tank on the Dixie Fire. Posted Aug 6, 2021. Lassen National Forest photo.

The Parliament in Victoria, Australia has passed legislation that extends the presumptive disease program to wildland firefighters. It also includes “surge firefighters” who are government employees normally in other roles, but who perform firefighting duties during the fire season as part of their agency’s surge capacity as needed.

The presumptive disease program ensures that if a firefighter is diagnosed with any of the 12 listed cancers, they will not have to prove that it was caused by their employment, and it will be considered an on the job injury.

The cancers covered are brain, bladder, kidney, non-Hodgkins lymphoma, leukemia, breast, testicular, multiple myeloma, prostate, ureter, colorectal, and esophageal. The employee must have been on the job for 5 to 15 years, depending on which disease they have.

The presumptive right will apply to individuals diagnosed on or after June 1, 2016 if the diagnosis occurs during the course of a person’s service as a firefighter or within 10 years after they have ceased to serve.

Lily D’Ambrosio, the Minister for Energy, Environment and Climate Change, explained the program in detail during the second reading of the bill. Here is a link to the legislation.

Wildland firefighters are at high risk for cardiovascular disease, lung cancer, and other illnesses, including chronic conditions in their knees, shoulders, and backs.

This is an important issue that should also be addressed for federal firefighters in the United States. The Grassroots Wildland Firefighters organization endorsed this type of a program in a position paper.