A woman wears a mask in central Moscow to "protect" herself from smoke from fires outside the city. August, 2010. Photograph: Mikhail Voskresensky/Reuters
When the Fourmile Canyon fire was burning west of Boulder, Colorado in September, 2010, Jim Roberts, a chemist with NOAA’s Earth System Research Laboratory, was surrounded by something he had previously studied at the U.S. Forest Service’s Missoula Fire Science Laboratory in Montana — smoke, and lots of it. In Missoula he used a new instrument they had built, a custom mass spectrometer, to examine the levels of isocyanic acid in the atmosphere and in smoke. Isocyanic acid has been difficult to detect with conventional measurement techniques. At Missoula, he measured the levels of the chemical in smoke generated when the researchers burned vegetation in the lab and in cigarette smoke.
When the Fourmile Canyon fire started, Roberts had the mass spectrometer at the University of Colorado at Boulder’s Cooperative Institute for Research in Environmental Sciences.
Here is an excerpt from the Daily Camera:
Isocyanic acid easily dissolves in water, which makes it possible for the acid to also dissolve into moist tissues in the body, including the lungs. The full health effects of exposure to isocyanic acid in the air aren’t fully understood, but the chemical has been linked to cataracts, cardiovascular disease and rheumatoid arthritis.
Last September, the researchers had the opportunity to measure the presence of the acid in a real wildfire. On Labor Day, the Fourmile Fire began burning in the foothills west of Boulder, just a few miles upwind of the state-of-the-art atmospheric instruments housed at NOAA’s campus on Broadway.
“Boulder has a world-class atmospheric chemistry building and only once in its lifetime is it going to have a full-on hit from a wildfire,” said Joost de Gouw, a co-author of the study and a researcher at the Cooperative Institute for Research in the Environmental Science. “So just everyone in that building turned on their instruments.”
CIRES is a joint institute of the University of Colorado and NOAA.
The sensitive new spectrometer used in Missoula also picked up the isocyanic acid in the plume of smoke from the Fourmile Fire.
More information
Smoke from the Fourmile fire as imaged by the MODIS satellite on September 6, 2010.
More information has come to light regarding the article we wrote last week about “Cancer risk and smoke exposure among wildland firefighters“. In response to an email, we heard from Brian Sharkey of the USFS’ Missoula Technology and Development Center, an exercise physiologist who was instrumental in the design of the Step Test and Work Capacity Test for wildland firefighters. We asked Mr. Sharkey if he was aware of any studies that considered a possible increased cancer risk for wildland firefighters. He said no, and:
However, our 1997 risk assessment (Booze in Health Hazards of Smoke, 1997) showed an increased risk only when we used “worst case scenario” – which estimated career exposure at exposure levels 95% of highest values measured. No one works for 25 years anywhere near those values. Also, some carcinogens are not as high on fires as they are in winter (from burning wood in stoves) (Smith et al.).
Structural FF do not have increased risk of lung cancer. Chinese women who cook over coal fires have more cancer – those who cook over wood fires do not.
We need a study of health effects that looks at all causes of morbidity and mortality – not just cancer (where risk is about 1 in 3 for US population). We also need an injury/illness surveillance system that tells us the impact of fire on respiratory, cardiovascular and – yes – cancer.
We asked Mr. Sharkey what data supported his statement that “structural FF do not have an increased risk of lung cancer”, and he was in a hurry, about to leave for a “smoke meeting”, but referred to a study on Philadelphia firefighters. We found the 24-year old study to which Mr. Sharkey may be referring. Here is an excerpt, the Methods, Results, and Conclusions:
Methods
We conducted a retrospective cohort mortality study among 7,789 Philadelphia firefighters employed between 1925 and 1986. For each cause of death, the standardized mortality ratios (SMRs) and 95% confidence intervals were estimated. We also compared mortality among groups of firefighters defined by the estimated number of career runs and potential for diesel exposure.
Results
In comparison with U.S. white men, the firefighters had similar mortality from all causes of death combined (SMR = 0.96) and all cancers (SMR = 1.10). There were statistically significant deficits of deaths from nervous system diseases (SMR = 0.47), cerebrovascular diseases (SMR = 0.83), respiratory diseases (SMR = 0.67), genitourinary diseases (SMR = 0.54), all accidents (SMR = 0.72), and suicide (SMR = 0.66). Statistically significant excess risks were observed for colon cancer (SMR = 1.51) and ischemic heart disease (SMR = 1.09). The risks of mortality from colon cancer (SMR = 1.68), kidney cancer (SMR = 2.20), non-Hodgkin’s lymphoma (SMR = 1.72), multiple myeloma (SMR = 2.31), and benign neoplasms (SMR = 2.54) were increased among firefighters with at least 20 years of service.
Conclusions
Our study found no significant increase in overall mortality among Philadelphia firefighters. However, we observed increased mortality for cancers of the colon and kidney, non-Hodgkin’s lymphoma and multiple myeloma. There was insufficient follow-up since the introduction of diesel equipment to adequately assess risk. Am. J. Ind. Med. 39:463-476, 2001. Published 2001 Wiley-Liss, Inc.
Wildfire Today has called for a study on the cancer risks associated with wildland fire. Not just lung cancer. The study needs to be conducted by medical doctors and epidemiologists.
We also learned that a proposal was prepared by Joseph Domitrovich in December, 2008, for the US Forest Service Technology and Development Program to study the effects that carbon monoxide may have on the cognitive function of wildland firefighters. Here is an excerpt.
An extensive EPA review on CO effects (2000) concluded that behavioral impairments in healthy adults are not significant below 20% carboxy hemoglobin (COHb). However, some studies have showed mild impairments at 5% COHb or below. Cigarette smokers have COHb levels of 5-10%, sometimes as high as 15%. In view of the reported adverse effects among fire staff, suspect additive or synergistic interactions among pollutants that worsen the neurobehavioral effects that would be predicted from CO exposure alone.
PROPOSED TECHNOLOGY & DEVELOPMENT WORK:
The deliverable outcome of the proposed project is a report detailing the levels of smoke exposure and cognitive effects. This could then be used by IMT, crew bosses along with training (RX-410) to help better understand the potential cognitive effects when exposed to wildland fire smoke.
POTENTIAL BENEFITS:
This project will help us to better understand the effects of wildfire smoke on our cognition, which would increase safety of fire personal.
Wildfire Today recommends that this study be funded.
A “smoke meeting” is being held in Boise this week. It will interesting to see if anything that will benefit the health of firefighters will come out of the meeting. We understand that at least one actual medical doctor is beginning to be involved in smoke studies related to wildland firefighters, which is a step in the right direction.
NIOSH and the U.S. Fire Administration are conducting a study of cancer among firefighters. I talked with the physician/epidemiologist, Dr. Tom Hales, who is a co-investigator for the study which began in October, 2009 led by Travis Kubale, the study’s primary project officer. He said that over the next four years they will study firefighters from three fire departments: San Francisco, Chicago, and the District of Columbia. They will look at the causes of death of firefighters that have worked for the departments over the last 50 years and compare that with tumor registries in their local communities and the National Death Index for cause of death.
Dr. Hales said that they will ask the firefighters in the study if they have ever worked on wildland fires, but other than that, they will not collect data on firefighters who specialize in wildland fires. He also said that NIOSH has no plans to specifically study cancer rates among wildland firefighters, but emphasized that NIOSH has collected data on smoke exposure on active wildfires and prescribed fires (see below).
What about wildland firefighters?
It is unfortunate that wildland firefighters will not be evaluated in this study, but you have to consider that the probably-flawed TriData study only looked at structural firefighters, and the IAFF and IAFC who helped to push for this new study spend most of their energy and political capital on structural fire.
There needs to be a concerted effort to conduct a similar study on wildland firefighters. It should be led by a physician/epidemiologist and should evaluate the long term health and occurrence of cancer and other diseases among wildland firefighters. There is a lot of grant money out there and it should be possible to get some of it pointed towards this overlooked niche of firefighting.
Wildfire Today is calling out the following organizations to get together and put some pressure on FEMA, NIOSH, and the U.S. Fire Administration to get this done:
National Park Service
Bureau of Land Management
U.S. Fish and Wildlife Service
Bureau of Indian Affairs
U. S. Forest Service
National Wildfire Coordinating Group and their Risk Mgt. Comm.
State land management agencies
International Association of Wildland Fire
International Association of Fire Chiefs
International Association of Fire Fighters
Federal Wildland Fire Service Association
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Below are links to studies about smoke exposure on wildfires, as well as excerpts from a bibliography on the same subject.
Researchers have linked exposure to air pollution before birth with lower IQ scores in childhood. From an AP article:
The results are in a study of 249 children of New York City women who wore backpack air monitors for 48 hours during the last few months of pregnancy. They lived in mostly low-income neighborhoods in northern Manhattan and the South Bronx. They had varying levels of exposure to typical kinds of urban air pollution, mostly from car, bus and truck exhaust.
At age 5, before starting school, the children were given IQ tests. Those exposed to the most pollution before birth scored on average four to five points lower than children with less exposure.
That’s a big enough difference that it could affect children’s performance in school, said Frederica Perera, the study’s lead author and director of the Columbia Center for Children’s Environmental Health.
[…]
In earlier research, involving some of the same children and others, Perera linked prenatal exposure to air pollution with genetic abnormalities at birth that could increase risks for cancer; smaller newborn head size and reduced birth weight. Her research team also has linked it with developmental delays at age 3 and with children’s asthma.
The researchers studied pollutants that can cross the placenta and are known scientifically as polycyclic aromatic hydrocarbons. Main sources include vehicle exhaust and factory emissions. Tobacco smoke is another source, but mothers in the study were nonsmokers.
The study does not mention smoke from forest fires. The subjects were exposed to urban air pollution, such as vehicle exhaust.
But they do point out that polycyclic aromatic hydrocarbons (PCH) can cross the placenta, and researchers HERE and HERE have identified PCH as being produced by forest fires. We don’t want to stir up a hornets nest, but if there is a link between PCH, forest fires, and low IQ scores, it could be an earth-shaking revelation. We can only hope that the PCH in forest fires is different from that found in vehicle exhaust, and is benign.
It was just on November 21 that Wildfire Today covered a new study about the effects of smoke on wildland firefighters. Now another new study on the emissions from wildland fires provides more data on the particulates produced by the fires and how they affect the public. Some of the findings include:
The health threat to city dwellers posed by Southern California wildfires like those of November 2008 may have been underestimated by officials.
Detailed particulate analysis of the smoke produced by previous California wild fires indicates that the composition posed more serious potential threats to health than is generally realized, according to a new paper analyzing particulate matter (PM) from wildfires in Southern California.
The paper, entitled “Physicochemical and Toxicological Profile of Particulate Matter (PM) in Los Angeles during the October 2007 Southern California Wildfires,” will appear in Environmental Science and Technology. It confirms earlier studies by air polllution specialist Constantinos Sioutas of the USC Viterbi School of Engineering, who is also co-director of the Southern California Particle Center.
For the study Sioutas and colleagues from USC, the University of Wisconsin-Madison and RIVM (the National Institute of Health and the Environment of the Netherlands) analyzed the particular matter gathered during the fall 2007 blazes.
“Fire emissions produce a significantly larger aerosol in size than typically seen in urban environments during periods affected by traffic sources, which emit mostly ultrafine particles,” Sioutas said.
“Staying indoors may not provide protection from smoke particles in the absence of air conditioning or the ability to recirculate filtered indoor air. This is because the fire particles can penetrate indoor structures more readily than particles from vehicular emissions.”
According to Sioutas, the fires produce a dangerous mix. “The chemical composition of particles during the fire episodes is different than that during ‘normal’ days impacted by traffic sources.
The ability of the particulates to penetrate structures, even if windows are closed, and their potential ability to be absorbed by human tissues are a matter of concern. “More aggressive measures to avoid smoke seem to deserve study, including distribution of masks and evacuation to air conditioned environments, and closure of non-smoke secured schools,” said Sioutas, who holds the school’s Fred Champion Professorship of Civil and Environmental Engineering.
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The study’s recommendation about the “distribution of masks” is questionable, in light of other data reported by Wildfire Today. If they are referring to the cheap, disposable dust masks, the information we have seen (below) indicates that they cannot remove the small particulates in wildland fire smoke.
There have been a number of reports about the effects of smoke on firefighters. Now there is a new one by the Institut de recherché Robert-Sauvé en santé et en sécurité du travail (IRSST).
The substances of greatest concern are carbon monoxide, formaldehyde, acrolein, and respirable and inhalable particles. A second group of concern, but present at proportionally lower concentrations, includes benzene, carbon dioxide (CO2), nitrogen oxides, PAH, ammonia, and furfural. A third group of concern, but present at proportionally lower concentrations again, includes acetaldehyde, 1,3-butadiene, methane, methanol, styrene, acetonitrile, propionaldehyde, toluene, methyl bromide, methylethylketone, acetone, methyl chloride, xylenes, phenol, tetrahydrofuran, methyl iodide, and mercury. Data suggests that if wildland firefighters are exposed to 25 ppm of carbon monoxide (below the permissible exposure value), they may be overexposed to formaldehyde, acrolein, PAH (benzo[a]pyrene), and respirable particles.
The U.S. National Fire Protection Association has recently announced that it is proceeding with the development of a new wildland firefighting respiratory protection Standard, but it will be some time still before respirators certified for wildland firefighting will become available.
If administrative controls are unsuccessful in reducing exposures to acceptable levels, wildland firefighters should be provided with air purifying respirators for formaldehyde, respirable particulate matter, organic vapours and acids, acrolein, and PAH. However, wildland firefighters should be cautioned that at high work levels the effectiveness and duration of air purifying cartridges is unknown. There is also a concern that firefighters using air purifying respirators may unknowingly expose themselves to higher levels of contaminants not removed by their respirator than they would otherwise. Until a respirator is developed for wildland firefighting that effectively removes carbon monoxide, air purifying respirators should be used in conjunction with a carbon monoxide alarm.
Like “a mosquito through an open door”.
Firefighters, especially new ones, frequently ask if bandannas over the face will protect them from smoke. The answer is hell no.
“Respirable smoke particles, gases, and vapours would pass through a bandanna as readily as a mosquito thorugh an open door.”
Click on the image above to see a larger version.
In fact, even respirators, as inconvenient as they are, will not do the job according to the report.
None of the filtering respirators remove carbon monoxide (CO). All of the currently available respirators have serious shortcomings for use in a wildland fire situation. Even if they were effective, some wildland firefighters are understandably reluctant to accept negative pressure air purifying face masks for use at high work levels for long periods of time.
A full face mask is generally more comfortable than a half-face mask and it provides full eye protection. Full eye protection is necessary the case of contaminants exceeding the threshold limit value where the threshold limit value is based on irritant effects.
Since the contaminants having warning properties such as odour or irritant effects are removed by air purifying respirators, there is a legitimate concern that firefighters wearing such respirators might unknowingly expose themselves to higher levels of toxic contaminants not removed by the respirator than they would otherwise. This could easily result in over exposure to carbon monoxide and lead to serious, perhaps deadly, consequences. To avoid this, a carbon monoxide monitor with alarm should be used in conjunction with air purifying respirators used when fighting wildland fires.
So, forget about the bandanna, and throw away that $84 piece of crap Hot Shield mask that is advertised to have the “ benefit of blocking & reducing the inhalation of smoke & ash particulate”. These smoke particulates are so small, that if one were released near the ceiling in a room with calm air, it would take eight hours to fall to the floor.
The sad truth is, in 2008 there is no practical way to protect wildland firefighters from the byproducts of combustion. Maybe the new 8-pound SCBA being developed will lead to something that could benefit wildland firefighters. Using this new technology, perhaps a 15-pound unit would give you an hour’s worth of air? This might help for initial attack, but for the hot shot crew on the line for 16 hours, sorry, you’re out of luck.
