Study: firefighters’ lung function decreases after exposure to smoke

A new study from the University of Georgia found that lung function decreases for firefighters who work on prescribed fires for multiple days and are exposed to smoke. Further, it showed that respiratory functions slowly declined over a 10-week season.

Unfortunately, even though the study was probably funded by taxpayers, you will have to pay a second time see the study’s results. It will cost you $41 to purchase the article that contains the detailed findings uncovered during the research. The University of Georgia decided to pay a private journal to publish the article, rather than placing it on the

Smoke, fire-N-of-Cascade-Rd-2006
Firefighter working in smoke, fire near Hot Springs, SD in 2006. Photo by Bill Gabbert

University’s web site for free. We have written previously about taxpayers not being able to access taxpayer-funded research. Why does the government continue to fund research, if the product of the research is not made available? A call to Luke Naeher, the senior author of the study, was not immediately returned.

Here is a summary of the report, which thankfully, is provided by the University of Georgia at no cost.

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December 5, 2011

After monitoring firefighters working at prescribed burns in the southeastern United States, University of Georgia researchers found that lung function decreased with successive days of exposure to smoke and other particulate matter.

“What we found suggested a decline in lung function across work seasons,” said Olorunfemi Adetona, a postdoctoral research associate and lead author of the study published recently in the journal Inhalation Toxicology.

Luke Naeher, senior author and associate professor in the UGA College of Public Health, explained that the study was designed to investigate whether the 26 firefighters experienced a decrease in lung function working at prescribed burns compared with days they spent away from the fires. Previously, researchers had looked only at changes in lung function of wildland firefighters on days with exposure to smoke.

“Over a 10-week season, these workers’ respiratory functions slowly declined,” Naeher said, adding that there is need to investigate the degree to which these declines returned to their baseline after the burn season. Although results of the study show that lung function at the start of two burn seasons in a limited number of nine firefighters in 2003 and 2004 did not vary significantly, more definitive answers relating to the issue of longer term effect of exposure on lung function would require a different study design.

In recent years, the U.S. Forest Service has sought to better understand and improve its occupational exposure limits for firefighters across the country. Most studies have concentrated on burns in Western states where exposure to and composition of wood-smoke particulate matter may vary to some degree when compared with fires in the Southeast, including South Carolina, where the study was done.

Naeher said the study provides some preliminary information regarding the health effects of fine particulate matter exposure that is intermediate between two exposure extremes. On the low extreme lies ambient air levels typical for developed countries, while inhalation of particles by a smoker represents the opposite extreme. Much research in the field has focused on health effects at both extremes. However, the study of exposure at intermediate levels, like that experienced by wildland firefighters, and women and children exposed to indoor air pollution from cook stoves in developing countries is limited. Naeher’s research focuses on these two different populations, and he explains that the study of the body’s response tothese intermediate exposures may now be more urgent. For example, Naeher said, an initiative led by the United Nations Foundation aims to put clean-burning cooking stoves in 100 million homes in developing countries by 2020.

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UPDATE: We heard from Luke Naeher on December 14, 2011. He told us that the research was funded by the University of Georgia, and the Department of Energy-Savannah River Operations Office through the U.S. Forest Service. He sent us copies of two research papers that were published in journals owned by Informa, a company with their head office in Switzerland: Personal PM2.5 Exposure Among Wildland Firefighers Working at Prescribed Forest Burns in Southeastern United States, and Lung function changes in wildland firefighters working at prescribed burns. Mr. Naeher said he cannot change the system in place for reporting science in the peer-review literature, but he will always share his published work freely with anybody who asks

Wildland firefighters: rhabdomyolysis or “rhabdo” can be extremely serious

Employee's left leg after 5 surgeries
From the FLA. Employee’s left leg after 5 surgeries

I will have to admit that when the National Wildfire Coordinating Group’s Risk Management Committee distributed some information earlier this year about rhabdomyolysis, which is frequently referred to as “rhabdo”, I didn’t pay much attention. But today when the Wildfire Lessons Learned Center announced that a Facilitated Learning Analysis (FLA) for a severe case of rhabdo was available, I read it carefully and am now converted. The injury in the FLA occurred September 21, 2011 while a firefighter was taking the Work Capacity Test, or “pack test”. I have seen the light and realize how serious this condition can be.

Left untreated, or if not treated early enough, rhabdo can  lead to irreversible muscle damage, permanent disability, kidney failure possibly requiring lifelong dialysis, and even death. Up to 8% of cases of rhabdomyolysis are fatal according to a NIOSH report. And all of this can be the result of exercising hard or engaging in a strenuous fire assignment if other risk factors are also present.

Rhabdomyolysis is the breakdown of muscle fibers resulting in the release of muscle contents (myoglobin) into the bloodstream which are harmful to the kidneys and may lead to kidney failure.

The link between rhabdo and “compartment syndrome”, the condition that is emphasized in the FLA, is certain, but it is not clear to me, having much more fire training than medical training, if compartment syndrome leads to rhabdo or vice versa, and my research found conflicting information. But that is not really important, in that both conditions are similar in that they are caused by damaged muscle tissue. Compartment syndrome occurs when the damaged muscle is inside an enclosed compartment in a fibrous sheath with other muscles, as is found in the arms and legs. Rhabdo can occur with any muscles, but both can lead to the same outcome, including death.

I was disappointed that the recently released FLA did not state the cause of the injured employee’s compartment syndrome/rhabdo, nor did it provide much useful information about how to prevent a similar occurrence, other than to “prioritize staying physically fit”, and the “incorporation of healthy lifestyle choices and better nutrition”. So I attempted to gather some information here in one place that will hopefully be useful for wildland firefighters, to increase their chances of avoiding rhambdo, or diagnosing it if it occurs.
Continue reading “Wildland firefighters: rhabdomyolysis or “rhabdo” can be extremely serious”

The myth of drinking water

Above: Firefighter on the Shep Canyon fire in South Dakota, September 6, 2011. Photo: Bill Gabbert/Wildfire Today.

After reading our excerpt and later the full document from the the Serious Accident Investigation Factual Report  for the hyperthermia fatality on the CR 337 fire in Texas, we heard from Dr. Brent Ruby, who has completed studies on this exact issue, even having studied wildland firefighters while they were working on fires. In one of his studies he was monitoring a wildland firefighter outfitted with a core temperature monitor, an ambient temperature sensor, and a special Camelback hydration system that monitored his water intake. This firefighter experienced a heat-related illness, heat exhaustion, and had to be evacuated off the fireline by a helicopter. That was a terrible thing to happen to a firefighter, and I’m sure the researchers thought the same thing, but it was probably a once in a lifetime cornucopia of incredibly useful data. Dr. Ruby sent us this message, reprinted here with his permission:

I was bothered by the findings of the CR337 fatality report from the investigation team. There are issues within this case that are very similar to a published heat exhaustion case study we published recently (Wilderness and Environmental Medicine 22, 122-125, 2011, http://www.ncbi.nlm.nih.gov/pubmed/21664560). In this report, we document drinking behavior, activity patterns, skin and core temperatures in a subject that suffered heat exhaustion and required evacuation. The lessons learned from this research clearly indicate that the best protection against a heat injury is reducing work rate. [*the abstract from the study is below]

Aggressive hydration strategies are over-preached and may provide a false sense of protection. It should be emphasized that the autopsy report as described in the fatality report indicated no signs of dehydration or electrolyte imbalance. I have tried to push these concepts to crews and safety officers when I get a chance to speak to them at meetings. I was bothered by this fatality knowing that it is seemingly directly linked to some of our research findings. I have tried to emphasize this to anyone that will listen in the world of wildfire.

You can certainly review our website to gain a better understanding of the publications we have done from research with the WLFF http://www.umt.edu/wpem. We have a great deal of physiological data, hydration, energy demands of the job, importance of supplemental feedings, etc. from all our work over the years. This peer reviewed research provides objective, scientific evidence that can be used to to change or influence policy to enhance safety on the line.

Let me know if you have any questions.

Regards, Brent Ruby

Brent C. Ruby, Ph.D., FACSM

Director, Montana Center for Work Physiology and Exercise Metabolism, The University of Montana

* Here is the abstract from the study:

Wilderness Environ Med. 2011 Jun;22(2):122-5.

High work output combined with high ambient temperatures caused heat exhaustion in a wildland firefighter despite high fluid intake.

Cuddy JS, Ruby BC.

Montana Center for Work Physiology and Exercise Metabolism, The University of Montana, Missoula, MT 59812-1825, USA.

The purpose of this case study is to examine the physiological/behavioral factors leading up to heat exhaustion in a male wildland firefighter during wildland fire suppression. The participant (24 years old, 173 cm, 70 kg, and 3 years firefighting experience) experienced heat exhaustion following 7 hours of high ambient temperatures and arduous work on the fire line during the month of August. At the time of the heat-related incident (HRI), core temperature was 40.1 °C (104.2 °F) and skin temperature was 34.4 °C (93.9 °F). His work output averaged 1067 counts·min(-1) (arbitrary units for measuring activity) for the 7 hours prior to the HRI, a very high rate of work over an extended time period during wildfire suppression.

In the 2.5 hours leading up to the heat incident, he was exposed to a mean ambient temperature of 44.6 °C (112.3 °F), with a maximum temperature of 59.7 °C (139.5 °F). He consumed an average of 840 mL·h(-1) in the 7 hours leading up to the incident and took an average of 24 ± 11 drinks·h(-1) (total of 170 drinks). The combined effects of a high work rate and high ambient temperatures resulted in an elevated core temperature and a higher volume and frequency of drinking than typically seen in this population, ultimately ending in heat exhaustion and removal from the fire line.

The data demonstrate that heat-related incidents can occur even with aggressive fluid intake during wildland fire suppression.

Unfortunately, even though Dr. Ruby’s research is funded by taxpayers through the National Institutes of Health, the National Science Foundation, and the Department of Defense, taxpayers are blocked from seeing the full results unless they pay a fee to the privately owned company that published the paper. We have written before about the results of taxpayer-funded wildfire-related research being held hostage by private companies. Dr. Ruby told Wildfire Today that he will send a copy of his paper to individuals that write to him at brent dot ruby at mso dot umt dot edu

The combined information about the fatality of Caleb Hamm on the CR 337 fire and Dr. Ruby’s study on wildland firefighters, is shocking. From the abstract, again:

The data demonstrate that heat-related incidents can occur even with aggressive fluid intake during wildland fire suppression.

Working on a wildfire on a hot day can lead to heat exhaustion and hyperthermia, and can be fatal EVEN IF a person drinks plenty of water and is not dehydrated.

Symptoms and prevention

We asked Dr. Ruby for more information:

Exertional hyperthermia occurs when the metabolic heat production from hard work overwhelms the bodies ability to off load it to the environment. This unloading can be blocked by clothing and/or slowed due to high radiant heat from the sun or an adjacent fire.

The basic symptoms of heat exhaustion are commonplace and can include profuse sweating, weakness, nausea, sometimes vomiting, lightheadedness, headache and sometimes mild muscle cramps.

The best approach [to prevent heat exhaustion and hyperthermia] is to know thyself and thy physical limits. Establishing a pace schedule that allows temperature to come back down in between periods of work that result in a rise in temperature. The factors of importance are pace, fitness level for the task at hand, hydration behaviors and simultaneously electrolyte concentrations in the blood.

It is important for wildland firefighters to drink plenty of water, but this will not, by itself, totally eliminate all chances of heat-related illness.

Be careful out there.

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UPDATE  October 27, 2011:

Dr. Ruby sent us the following list of other publications on similar topics that are in peer reviewed journals. I assume that most of them are not available to the public (don’t get me started on that again!) unless you pay the ransom fees at the private companies, or send a message to Dr. Ruby:  brent dot ruby at mso dot umt dot edu

Dr Ruby articles

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UPDATE October 28, 2011:

The U.S. National Library of Medicine has an excellent article about heatstroke, which can follow heat cramps and heat exhaustion and is life-threatening. The article includes causes, symptoms, first aid, what not to do, when to call 911, and prevention (including “avoid exercise or strenuous physical activity outside during hot or humid weather”. Good luck with that one, firefighters.)

9/11 health care bill does not cover firefighters’ cancer

Remember the huge battles to get the bill passed to provide health care for the firefighters that were suffering from medical issues after working in the debris from the towers that fell during the 9/11 attacks? Most of us felt a huge relief when the “S. 1334: James Zadroga 9/11 Health and Compensation Act of 2009“ was finally passed. We wrote about it several times, with the latest being HERE.

It turns out that the bill, or at least the way the provisions are being interpreted, does not cover the treatment of cancer for the firefighters that worked on the debris pile. Cancer — you would think this would be close to the number one condition covered for the people that worked in that toxic environment.

John Howard, the World Trade Center Health Program administrator, said in a statement that cancer would not be covered because there is not adequate “published scientific and medical findings” that a causal link exists between September 11 exposures and the occurrence of cancer in responders and survivors. So if we wait, and study the link for another, what, 20 or 30 years we can prove it then?

This is a disgrace.

Jon Stewart of the Daily Show, in a piece named “I Thought We Already Took Care of This S@#t”, expresses his opinion on the issue. The clip has profanity, but it is bleeped out.

NorthJersey.com has more details about this development.

Meanwhile, the Canadian government has a vastly different approach. For years the provinces of Alberta and Manitoba have had presumptive coverage for a list of conditions for firefighters. If they are diagnosed with one of the cancers on the list, it is considered an occupational disease and they may be eligible for workers compensation benefits. In fact, Alberta expanded their list in May to include prostate, breast, skin and multiple myeloma, bringing the total to 14 types covered under the Workers Compensation Board. Their government acknowledges that firefighters are at a greater risk of contracting cancer than the general public, and it can be difficult or impossible to prove that a particular case of cancer was caused by a specific incident or exposure, on or off the job.

The future of wildland fire smoke research

JFSP smoke research planThe Joint Fire Science Program (JFSP) has released their plan for wildland fire smoke research. The 58-page document outlines their priorities for funding smoke research through 2015.

Much of the emphasis appears to be directed at how to deal with the public’s perception and tolerance of smoke. Smoke is becoming an increasingly sensitive subject to the population due to larger wildfires burning for longer periods of time, concern about the effects of wildfire smoke on global warming, and prescribed fires continuing to be an important tool for land managers.

One aspect of wildfire smoke that Wildfire Today has written about frequently is the short and long term effects of smoke on the health of firefighters. On April 23, 2010 we covered the study that NIOSH and the U.S. Fire Administration are conducting about cancer among structural firefighters. We called out the land management agencies and the firefighting associations:

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.

Followups to that article are HERE and HERE.

The JFSP five-year plan does mention research on the effects of smoke on wildland firefighters, but at times it seems like an afterthought. For example, the objective for one of four research themes, “Smoke and Populations”, sometimes includes the “impact of smoke on populations” (page 26), and in other places it is described as “impact of smoke on populations and fire fighters” (page 21).

However, the plan does list some specific “Smoke Science Foci” that may benefit firefighters:

  • 2011: (SSP T3 -2): Epidemiological research/literature review to determine human health risk from high PM loadings.
  • 2011 (SSP T3-4): Fire fighter smoke health hazards: trends in health and exposure.
  • 2012 (SSP T3-5): Review of epidemiological research to determine human health risk from high PM, high ozone and high aromatic hydrocarbon loadings with a focus on synergisms between pollutants.

We hope that the “foci” turns into actual research.

Siren settlement: Federal Signal agrees to pay firefighters $3.8 million for hearing loss

sirenFederal Signal Corporation has reached a settlement with 1,125 firefighters who claim they have hearing loss caused by the company’s sirens. Federal Signal has been fighting numerous law suits from firefighters for years. In the settlement the company agreed to pay $3.8 million to the firefighters represented by attorney Joseph Cappelli.

If you are an emergency responder who rides in a piece of apparatus with a siren mounted on the cab roof, or if you keep the windows down while the siren is blasting, you may have an increased risk of hearing loss.  But even if your siren is on the front bumper you may still be at risk from the siren as well as the low frequency engine sounds which are transmitted through the bones in your skull to your ear. Headsets and ear plugs will provide little protection from the low frequency sounds.

To reduce your chances of hearing loss from the siren:

  1. Wear ear plugs or a sound-attenuating headset.
  2. Keep the windows up while responding.
  3. Remove the siren from the top of the cab and install it on the front bumper.
  4. Turn off the siren when you don’t need it.

More information about the dangers of hearing loss from sirens is HERE and HERE. And HERE is an interesting article that compares electronic sirens to electro-mechanical sirens.

And if your fire engines participate in parades, do not blast the sirens, no matter where they are located on the apparatus. In my town, the fire department has been known to blast the sirens from six to eight engines all at the same time in parades, while they drive very slowly past hundreds of spectators 10 feet away.