Long-term effects of smoke exposure can be difficult to determine

Above: Firefighters arrive at the White Tail Fire in South Dakota, March 8, 2017. Photo by Bill Gabbert.

Researchers are finding it difficult to conduct research on the long-term effects of exposure to smoke from wildfires. Last year in some areas of the Northern Rockies in the United States and Canada residents suffered through one of the worst seasons of smoke in a while.

Below are excerpts from an article at Pacific Standard. Most of it is about the effects on residents, but it also mentions firefighters.

“Seeley Lake was the worst smoke event we have ever seen, and I think possibly has been seen, at least in the United States and Canada,” [Sarah] Coefield says. “Every single day, the smoke is hazardous. I’d wake up every hour at night, and check the smoke, and then fret about Seeley Lake. What do I say in the morning? ‘It’s terrible. Again.'”

[…]

Then there is the difficulty of securing the financial resources to undertake a long-term study. Even researching the effects of smoke on firefighters—who, with their regular and intense exposures to wildfires, are among the worst affected—can be difficult, says John Balmes, professor of environmental health sciences at the Berkeley School of Public Health.

“Occupational studies of wildland firefighters are a problem because it’s a workforce that tends to turn over a lot,” he says. For one study, he followed a group of firefighters across the fire season to monitor their exposure, but didn’t get the funding needed to follow up on their health the next year—a progression that could have shed light on the long-term effects of smoke.

Smoke affecting much of the U.S.

Above: Blue Sky’s prediction for PM2.5 particulate matter for May 1, 2018.

Smoke from four large wildfires, agricultural burning, and prescribed fires are pumping a great deal of smoke and particulate matter into the atmosphere. These maps, created by the Forest Service’s Blue Sky program, show predictions for the amount of very small smoke particles, 2.5 micrometers in diameter or smaller, which can only be seen with an electron microscope. Fine particles, known as PM 2.5, are produced from all types of combustion, including motor vehicles, power plants, residential wood burning, forest fires, agricultural burning, and some industrial processes.

map prediction smoke particulate matter pm2.5
Blue Sky’s prediction for PM2.5 particulate matter for May 2, 2018.

The Tinder Fire has burned 11,420 acres in central Arizona and is being suppressed.

The OK Bar Fire in extreme southern New Mexico is 44,000 acres and is not being fully suppressed.

A Type 1 Incident Management Team has been ordered for the 2,000-acre McDannel Fire in west Texas 21 miles west of Ft. Davis.

The 5,800-acre North County Road 7 Fire is burning in northern Minnesota five miles south of the Canadian border 11 miles northwest of Greenbush. The fuels burning are mostly grass and swampland, said Christi Powers, an information officer for the Minnesota Interagency Fire Center in Grand Rapids, Minn.

 

2017 North American wildfire smoke equivalent to volcano eruption

The pollution remained in the stratosphere at measurable levels for several months.

Southern California wildfires satellite view
Southern California wildfires, satellite view, December 5, 2017. NASA

The smoke and pollution created during the very active wildfire season in Canada and the United States last year was equivalent to a moderate volcano eruption according to scientists.

Below is an excerpt from an article at GeoSpace:

The overall impact of the 2017 North American fires on the stratosphere surpassed all other documented wildfire events since the beginning of stratospheric observations in the 1980s and had an effect equivalent to a volcanic eruption, according to the study’s authors.

“This event was so big and its fires were so powerful that not only did they inject material into the stratosphere, they injected enough material that the stratosphere was polluted on a hemispheric scale,” said Sergey Khaykin, an atmospheric scientist at Versailles University (UVSQ) in France, and lead author of the new study in Geophysical Research Letters, a journal of the American Geophysical Union. “The effect really was comparable to a moderate volcanic eruption.”

arizona wildfire volcano
This wildfire in Arizona in 1988 only LOOKS like a volcano.

Study shows firefighters’ exposure to smoke increases disease risk

Depending on the type of work performed and the number of years of exposure, the increased risk can be 22 to 39 percent.

Above: Smoky conditions on the Legion Lake Fire in Custer State Park in South Dakota, December 12, 2017. Photo by Bill Gabbert.

Originally published at 6:02 p.m. MT, February 6, 2018.

After collecting data from wildland firefighters in the field, a group of researchers concluded that firefighters’ exposure to smoke can increase the risk of mortality from lung cancer, ischemic heart disease, and cardiovascular disease. In this first section we cover what is in vegetation fire smoke, and after that we have details about the additional mortality risk faced by firefighters who can’t help but breathe the toxic substances.

What is in the air that firefighters breathe?

There have been many studies about smoke dating back to the 1988 NIOSH project at the fires in Yellowstone National Park. Most of them confirmed that yes, wildland firefighters ARE exposed to smoke and in most cases they quantified the amount.

In 2004 Timothy E. Reinhardt and Roger D. Ottmar  found a witches’ brew of methyl ethyl bad stuff that firefighters are breathing. All of these are hazardous to your health:

  • Aldehydes (volatile organic compounds); can cause immediate irritation of the eyes, nose, and throat, and inhalation can cause inflammation of the lungs. Short-term effects include cough, shortness of breath, and chest pain. The most abundant aldehyde in smoke is formaldehyde. When formaldehyde enters the body, it is converted to formic acid, which also is toxic.
  • Sulfur dioxide (SO²); causes severe irritation of the eyes, skin, upper respiratory tract, and mucous membranes, and also can cause bronchoconstriction. It forms sulfuric acid in the presence of water vapor and has been shown to damage the airways of humans.
  • Carbon monoxide (CO); As CO is inhaled it displaces O2 as it attaches to red blood cells and forms COHb. COHb reduces the ability of the blood to carry oxygen and causes hypoxia (a condition in which the body does not receive sufficient oxygen). Due to their strenuous work, wildland firefighters often have increased respiratory rates, which will increase the amount of CO being inhaled when smoke is present. COHb has a half-life (the time it takes half of the COHb to dissipate from the body) of about 5 hours. Symptoms of CO exposure include headaches, dizziness, nausea, loss of mental acuity, and fatigue. Prolonged, high exposure can cause confusion and loss of consciousness
  • Particulate matter; Respirable particulates are a major concern as they can be inhaled into the deeper recesses of the lungs, the alveolar region. These particles carry absorbed and condensed toxicants into the lungs
  • Acrolein; may increase the possibility of respiratory infections. It can cause irritation of the nose, throat, and lungs. Long-term effects can include chronic respiratory irritation and permanent loss of lung function if exposure occurs over many years.
  • Benzene; can cause headaches, dizziness, nausea, confusion, and respiratory tract irritation. Although the human body can often recover and repair damage caused by irritants, prolonged exposure from extended work shifts and poorly ventilated fire camps can overwhelm the ability to repair damage to genes and deoxyribonucleic acid (DNA).
  • Crystalline silica; can cause silicosis, a noncancerous lung disease that affects lung function. But OSHA classifies it as a carcinogen.
  • Intermediate chemicals; have been shown to cause a variety of health problems including bronchopulmonary carcinogenesis, fibrogenesis, pulmonary injury, respiratory distress, chronic obstructive pulmonary disease (COPD), and inflammation.

One of the more recent research efforts, from 2009 to 2012, was led by George Broyles of the U.S. Forest Service, National Technology and Development Program, in Boise, Idaho. They collected data in 11 fuel models in 17 states on initial attack, prescribed burns, and large project fires. The group measured carbon monoxide (CO) with electronic datalogging dosimeters and particulate matter using air pumps and filters.

carbon monoxide exposure firefighters
Data from the 2009-2012 wildland firefighter study led by George Broyles. “TWA” stands for Time Weighted Average. CO is carbon monoxide. OEL is Occupational Exposure Limits.

Monitoring carbon monoxide (CO) can be important, and is also fairly easy to do and not terribly expensive. Researchers have found that it can be a surrogate for the primary irritants of concern in wildland smoke near the combustion source. If CO is present, it’s almost certain that the smorgasbord of nasty stuff is in the air.

wildfire smoke monitoring firefighters
Jon Richert displays the various devices the National Technology Development Center research crews use to measure the amount of smoke firefighters deal with during wildfire suppression. This equipment was used in 2016 in a different but similar study than the one described in this article.
Diffusion tube
Diffusion tube.

Electronic CO monitors are available for $100 to $300. Another option is the little disposable CO monitors called diffusion tubes. With the holder they are about the size of a dry erase marker. Many are made by Drager, and for eight hours can record the cumulative CO. You can’t get an instantaneous reading, but the total hourly exposure can be monitored. They cost about $13 each. If one or two people on the crew carry them it can provide a heads up if the air quality is really bad.

What are the health effects of smoke exposure on a wildland fire?

Employers in most if not all workplaces are required to minimize hazards and provide a safe working environment. But of course it is impossible to totally eliminate all risks to firefighters. A cynic might assume that leadership in the wildland fire community may be hesitant to ask the question if they don’t want to hear the answer.

In spite of numerous studies confirming that yes, there is smoke where wildland firefighters work, there has been little in the literature that quantifies the effects on a person’s health. A new study published in August, 2017 contains a preliminary analysis addressing that question.

It is titled Wildland Fire Smoke Health Effects on Wildland Firefighters and the Public – Final Report to the Joint Fire Science Program. The authors are Joe Domitrovich, George Broyles, Roger D. Ottmar, Timothy E. Reinhardt, Luke P. Naeher, Michael T. Kleinman, Kathleen M. Navarro, Christopher E. Mackay, and Olorunfemi Adetona.

They used the field data collected in the 2009 to 2012 George Broyles study to extrapolate the physical and health effects on humans. The authors actually came up with numbers that indicate firefighters’ relative mortality risk for lung cancer, ischemic heart disease, and cardiovascular disease.
Continue reading “Study shows firefighters’ exposure to smoke increases disease risk”

Grapes exposed to wildfire smoke may produce smoke-flavored wine

Wine grapes
Wine grapes. Photo by Fir0002.

From CFJC Today:

A new study out of the University of British Columbia Okanagan has looked at what happens to wine grapes when they are exposed to wildfire smoke.

Researchers found chemicals in the smoke can give wine an off-putting smoky flavour and aroma known as smoke taint — and those volatile phenols are absorbed quickly and remain in the grape long after the smoke has cleared.

The authors say while wine from those grapes can be smoke-flavoured, the grapes themselves taste normal, likely a result of the volatile phenols changing during the fermentation process.