Study shows firefighting puts a strain on the heart

A new study conducted in Scotland found that fighting fires could increase the risk of a heart attack.

Wildland firefighter fatality data collected by the National Interagency Fire Center from 1990 to 2014 shows that most of the deaths in that period were caused by medical issues (primarily heart related). The top four categories which account for a total of 88 percent are, in decreasing order, medical issues, aircraft accidents, vehicle accidents, and entrapments. The numbers for those four are remarkably similar, ranging from 23 to 21 percent of the total.

The new UK study suggests that exposure to heat and the physical exertion required to control a fire can cause firefighter’s blood to clot and is putting firefighters at risk of heart attack.

Physical analysis of 19 firefighters in Scotland also found that tackling blazes put a strain on their hearts and worsened the functioning of their blood vessels.

Previous work has shown that firefighters have the highest risk of heart attack of all the emergency services.

The new study reported that a heart attack is the leading cause of death for on-duty firefighters and they tend to suffer cardiac arrests at a younger age than the general population.

Nationwide in the US, around 45% of on-duty deaths each year among firefighters are due heart issues, and researchers at the British Heart Foundation (BHF) and Edinburgh University believe the situation in the UK is comparable, although they did not know the cause.

On two occasions, at least one week apart, they either performed a mock rescue from a two-storey building for 20 minutes or undertook light duties, in the case of the control group, for 20 minutes.

The firefighters wore heart monitors that continuously assessed their heart rate and its electrical activity.

Blood samples were also taken before and after, including measurement of a protein called troponin that is released from the heart muscle when it is damaged.

Those taking part in the rescue had core body temperatures that rose by 1C and stayed that way for three or four hours.

There was also some weight loss among this group, while their blood vessels also failed to relax in response to medication.

Their blood became “stickier” and was more than 66% more likely to form potentially harmful clots than the blood of people in the control group.

Dr Mike Knapton, associate medical director at the BHF, said: “Firefighters routinely risk their lives to save members of the public. The least we can do is make sure we are protecting their hearts during the course of their duties.”

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Below is a representation of the wildland firefighter data from NIFC, compiled by Wildfire Today. 

Wildland firefighter fatalities 1990-2014

Looking into the forces that drive wildfires

Pioneer Fire northeast of Boise, Idaho, August, 2016. USFS photo.

High Country News has an excellent article written by Douglas Fox that looks under the hood, so to speak, at the science that causes wildfires to burn the way they do. There are forces, unknown until the last decade or two, that are major influences on the spread of a fire, such as the 100 mph flamethrower-like jets of flame that may have contributed to the deaths on the 1994 South Canyon fire near Glenwood Springs, Colorado.

Mr. Fox writes in illuminating detail about state-of-the-art research being conducted by Janice Coen, David Kingsmill, Craig Clements, Mark Finney, Michael Reeder, and Brian Potter, as well as legacy research done by the the U.S. military in the 1940s that provided data on how to design incendiary bombs to burn down many of the buildings in Hamburg, Germany on July 27, 1943 in order to demoralize the workers in Germany’s critical U-boat industry.

Most of the article is about recent research on wildfires, but here is an excerpt about the military’s work in the 1940s in northwest Utah that facilitated the attack on Hamburg by the British that killed at least 42,000 people.

…The U.S. Army’s Chemical Warfare Service had commissioned Standard Oil Development Company to construct a row of steep-roofed European-style apartment buildings. Erich Mendelsohn, an architect who had fled Nazi Germany, specified every detail: 1 1/4-by-2-inch wood battens, spaced 5 7/8 inches apart, to hold the roof tiles; 1-inch wood flooring underlain by 3 1/2-inch cinderblocks, and so on — all to replicate the dwellings of German industrial workers. The wood was maintained at 10 percent moisture to mimic the German climate. Rooms were outfitted with authentic German curtains, cabinets, dressers, beds and cribs — complete with bedding — laid out in traditional floor plans.

Then, military planes dropped various combinations of charges on the buildings, seeking the most efficient way to penetrate the roofs and lace the structures with flame.

Those experiments offered clues on what factors could cause firestorms. And in the years following World War II, scientists would study Hamburg and other bombing raids to derive basic numbers for predicting when a firestorm might form: the tons of munitions dropped per square mile, the number of fires ignited per square mile, and the minimum area that must burn. They concluded that Hamburg’s unusually hot weather set the stage for the firestorm, by making the atmospheric layers above the city more unstable and thus easier for a smoke plume to punch through. Scientists theorized that this powerful rise had drawn in the winds that whipped the flames into even greater fury.

Research on firefighters that is not Open Access should be boycotted

For Throwback Thursday, here’s an article we originally published in 2011:

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Open Access logo
Open Access logo

We all hate paying for something and then not receiving what we paid for. That is what is happening now to taxpayers who pay for government-funded research and then have no access to the findings.

We have ranted about this before, and documented another example a few days ago when we discovered that it will cost us $41 to obtain a copy of the findings from research conducted by the University of Georgia. Associate Professor Luke Naeher and others 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.

This is not the only research that has explored the effects of smoke on wildland firefighters, but it may significantly add to the limited body of knowledge we have on the topic. We won’t know, however, unless we pay a second time in order to see their conclusions.

Researchers at some organizations receive pay raises and promotions based partially on the “publish or perish” meme. A system that requires researchers to publish in journals that are not completely open to the public, is antiquated and has no place in 2011 when a paper can be published in seconds on the internet at little or no cost.

Some of the research that has been conducted on firefighters requires a great deal of cooperation from the firefighters, including for example, ingesting core temperature monitors, carrying a drinking water system that monitors every drink they take, and even lubricating and then inserting a rectal thermistor probe attached to wires.

The Boycott

There is no reason for firefighters to go to extreme lengths to help researchers advance the researcher’s career paths unless the firefighters can receive some benefits from the project. So, we are jumping on the idea proposed by Rileymon in a comment on the University of Georgia article:

Maybe it’s time to suggest that firefighter/research subjects boycott new research studies unless the findings are put into the Public Domain?

Here is what we are proposing:

  1. Firefighters, administrators, and land managers should not cooperate with researchers unless they can be assured that findings from the research will be available to the public at no charge immediately following the publication of the findings, or very shortly thereafter.
  2. Researchers should conform to the principles of Open Access.
  3. Scientists who assist in the peer review process for conferences or journals should pledge to only do so only if the accepted publications are made available to the public at no charge via the internet.

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UPDATE February 22, 2017: There is a sign that the new Trump administration will be even less transparent than his predecessor. A great deal of data is now unavailable on the White House open data portal. It is possible this is just an unannounced temporary change…. we’ll see.

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More information:

 

Researchers find tree-bark thickness is affected by fire occurrence

The researchers found that the bark thickness of closely related species is linked to whether the species lived in a fire-prone or non-fire-prone region, which provided further evidence that bark thickness is an evolutionary adaptation to fire.

Above: firefighters mop up hot spots near a residence on the Eiler Fire in northern California, August 6, 2014. Photo by Bill Gabbert.

Researchers have determined that the thickness of bark on a tree can be affected by the frequency of fires within the region. Findings released in a paper today suggest that bark thickness could help predict which forests and savannas will survive a warmer climate in which wildfires are expected to increase in frequency.

Trees in regions where fire is common, such as savannas and the forests of western North America, tend to have thicker bark, while trees in tropical rainforests have thinner bark, researchers at Princeton University and collaborating institutions reported Jan. 11 in the journal Ecology Letters. Bark protects the inside of the trunk from overheating and is one of a handful of adaptations that trees use to survive fire.

“We found large-scale evidence that bark thickness is a fire-tolerance trait, and we showed this is the case not just in a particular biome such as a savanna, but across different types of forests, across regions and across continents,” said first author Adam Pellegrini, a NOAA Climate and Global Change Postdoctoral Fellow at Stanford University who led the study while a graduate student in Princeton’s Department of Ecology and Evolutionary Biology.

The research suggests that the link between bark thickness and fire resistance should be included in global climate models, Pellegrini said. “Trees from regions that burn frequently could still become vulnerable if the risk of fire increases,” he said. “The open question is whether the bark is thick enough to help trees survive.”

Pellegrini and his colleagues looked at 572 tree species in regions across the globe. They compared bark thickness from trees in areas that experience frequent wildfires — and where rain falls only seasonally — to trees in regions where fires are rare, such as tropical rainforests. They found that in areas where fires are frequent, most trees, no matter the species, have thicker bark than closely related tree species growing in low-fire areas.

The study suggests that tropical rainforests — which are mostly composed of thin-barked trees — may have a more difficult time recovering from fire, whereas savannas and seasonal forests with thickly barked trees should be able to better withstand fire. A savanna was defined as land with continuous grass cover that is 20 to 80 percent trees, while a forest was defined as having complete tree coverage and little to no grass.

Periodic fires are necessary for the health of some types of savannas and forests. Fires burn off excess plant matter such as dead wood and grass — as well as competing fire-sensitive species — and rejuvenate the soil so that the dominant, fire-resistant plant species can flourish. However, fires also can be detrimental to the environment by releasing stored carbon back into the atmosphere, and causing the decades-long loss of a valuable carbon-storage system.

North Pole Fire
North Pole Fire, west of Custer, South Dakota March 10, 2015. Photo by Bill Gabbert.

The researchers also addressed the question of where thick-barked trees come from: Did they evolve to have thick bark in response to living in a fire-prone region, or do thick-barked trees come from plant families with species that all tended to develop thick bark irrespective of fire activity? Continue reading “Researchers find tree-bark thickness is affected by fire occurrence”

Study links firefighter accidents to sleep problems

fire Whiskeytown National Recreation Area
An incident base at Whiskeytown National Recreation Area in California, 2009. Photo by Carol Jandrall.

A study of almost 7,000 firefighters from municipal fire departments found that 37 percent screened positive for common sleep disorders, including obstructive sleep apnea, insomnia, restless leg syndrome, and shift work disorder.

The researchers found that compared with sound sleepers, those with a sleep disorder were about twice as likely to have a motor vehicle crash, to nod off while driving, and to have cardiovascular disease or diabetes. They were more than three times as likely to suffer from depression and anxiety.

The study, published in the Journal of Clinical Sleep Medicine, said that nationwide 61 percent of firefighter on-duty fatalities are caused by heart attacks or motor vehicle crashes.

National Interagency Fire Center data that we reported for 1990 through 2014 shows that 45 percent of the wildland fire fatalities were from vehicle accidents or medical issues.

Wildland firefighter fatalities 1990-2014
Wildland firefighter fatalities, 1990-2014. Data from NIFC, compiled by Wildfire Today.

Most, 97 percent, of the 7,000 firefighters in the study worked extended shifts of at least 24 hours. Wildland firefighters work 8-hour shifts —  except when they don’t. While on fires their shift schedules and sleep routines are often disrupted. The 8-hour shift can be extended to 12 to 16 hours, and their usual sleeping times may be changed and sometimes shortened; not unlike the jet lag of traveling to a different time zone. The first shift on a fire may be longer than 16 hours and a crew used to working during the day can be placed on a night shift.

The municipal firefighters in the study work very different schedules from their brothers and sisters in wildland fire, so a direct comparison of sleep disorders and accidents is probably not valid, but this issue should be watched closely. Crew supervisors and incident management teams should, at least, see that firefighters have an opportunity to get an adequate amount of quality sleep.

The same journal that published this study has another interesting one titled, “The Association between Sleep Disturbances and Depression among Firefighters: Emotion Dysregulation as an Explanatory Factor”.

Australians expect to put wildfire modeling in the hands of firefighters

Above:  the Aurora national bushfire prediction, detection, simulation and early warning system.

Researchers in Australia are designing a wildfire modeling system that firefighters can access on a portable device in the field even if they are not connected to the internet. The Australis Wildfire Simulator is intended to be part of Aurora, a national fire prediction, detection, simulation and early warning system that simulates bushfires in real time and rapidly communicates the spread predictions via the web, email and the National Telephone Early Warning System (NTEWS).

Researchers at The University of Western Australia are developing the new touchscreen device that can be mounted in a fire truck to help firefighters predict where and when a bushfire will spread.

The researchers are modifying bushfire simulation software Australis into a high-end tablet to provide accurate predictions of fire behaviour more rapidly than current methods.

UWA Professor George Milne
UWA Professor George Milne.

Professor George Milne from UWA’s School of Computer Science and Software Engineering said the technology could protect lives, homes, crops and livestock in Western Australia’s bushfire prone areas.

“Having the Australis fire prediction technology in the cab of a fire truck or a farmer’s ute will enable first-responders to get the best information necessary to create appropriate firefighting and evacuation strategies,” Professor Milne said.

“This can happen in the very early stages of a bushfire, when time-critical responses are required.”

Professor Milne said the touchscreen device would complement the Aurora system used by the Department of Fire and Emergency Services (DFES) which currently runs the simulator from one central location for all fires in WA.

“On a day where there are several bushfires across the state, it may take too long to predict each individual fire’s progress using a single system in the central headquarters,” Professor Milne said.

“The advantage to local brigades with access to this technology is that it will give them location-specific information about which communities are at risk and which need to be evacuated.”

The Australis system analyses data including geographical topography, vegetation types, WA bushfire prone hotspots, time since last burn, rate of spread, fuel accumulation and forecasted weather.

Australis
Screen capture from the Australis fire modeling system.

In a matter of minutes, and without internet connectivity, it can accurately predict where the fire could be from 30 minutes to 24 hours into the future.

Professor Milne said WA is unique in the world; it has bushfires burning every day of the year, from the north during the winter dry to the south in summer.

“This technology could significantly minimise the impact of bushfires, the loss of lives and homes, by predicting the direction, intensity and rate of bushfire spread in real time,” he said.

Funding is still required to get the technology off the ground and made available to local bushfire brigades.

Along with DFES, Department of Parks and Wildlife and Landgate, the University of Western Australia has an application for Royalty for Regions funding under consideration by the WA State Government.