Follow-up on cancer risk among wildland firefighters

(Revised @ 2:50 MT, April 26, 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.

More information about wildland firefighters and smoke. It begins on page 8 (page 74 of the main publication).

Cancer risk and smoke exposure among wildland firefighters

(Note: after we wrote this article, more information came to light, and we wrote a follow-up piece.)

NIOSH and the U.S. Fire Administration are conducting a study of cancer among firefighters. HERE is a 2.1 Mb Powerpoint presentation describing the project.  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.

Continue reading “Cancer risk and smoke exposure among wildland firefighters”

FEMA awards grant to study whole-house fire shelter

In May, 2008, Wildfire Today wrote about two patents that were issued in the 1990’s for systems to deploy fire shelters, or fire-resistant blankets, to cover entire houses. These may or may not be feasible, but now the Federal Emergency Management Agency has awarded a $1 million grant to research the best material for whole-house fire-resistant blankets.

More information is here.

Thanks Dick

Mega-sized wind tunnel to test homes against 140 mph winds

A huge testing facility is being built in South Carolina that will be able to test the effects of winds up to 140 mph on full-size homes. In addition to testing for category 4 hurricane conditions, the lab will simulate the spread of burning embers in a vegetation fire. Researchers will evaluate the ignition potential of embers and look at ways to make homes less likely to burn when exposed to flaming debris.

The facility will use over 100 huge fans which consume so much electricity that it will only be used at full strength during off-peak hours, because it will draw enough electricity to power 9,000 homes.

Here is a video from WISTV. (If the video is not visible below, go to WISTV and on the right side of the article, click on the little red video symbol.)

Humbolt State’s fire lab

Morgan Varner in the HSU fire lab. Photo: Preston Drake-Hillyard

Humbolt State University in northern California is one of three universities in the U.S. with a fire lab. Here is an excerpt from an article in the student-run newspaper:

You smell it as soon as you walk into the Natural Resources building: that familiar campfire smell. What you’re experiencing is HSU’s fire lab. Students come here to start fires.

The fire lab is an opportunity for students to learn about wildfires in a hands-on environment and provide fire science research for agencies throughout the nation. It’s a rare resource: only three universities in the U.S. have fire labs.

J. Morgan Varner III is an associate professor of wildland fire science. He oversees the fire lab, and he’s visibly excited by his work. “Most research is mundane stuff” he says, eyebrows raised. “We get to burn stuff.”

At first glance, the lab is nothing special. It’s a medium-sized classroom with 24 seats. The fire table is a piece of steel tabletop with a low-tech, hand-drawn ruler rising vertically off of it. Varner lowers an enormous ventilation hood. Smoke is sucked out of the building, allowing indoor burns.

Varner starts a burn. He lays down cotton strings soaked in an accelerant and casually tosses a handful of Washoe Pine needles on top. He lights the ends of the string with a standard barbecue lighter. The pile of duff quickly ignites.

As the pile burns, Varner points out the height of the flames. This simple datum is the core of the fire lab’s work. It shows the energy contained in wildfire fuel- leaves, pine needles, sticks and logs – and how it burns. The way different fuels burn is key to the prevention of wildfires. Flame patterns, color and the ash and residue left behind all add to the understanding of how fuels burn. Temperature is crucial. The goal is to see how hot fires get and how much plants can withstand.

[…]

Varner laments the lack of field opportunities provided by the school. Fears of liability from the state prevent the forestry department from carrying out field studies in fire season. Some students take on summer internships involving wildfires. Varner expresses excitement and jealousy about the stories that students bring back from their experiences. He feels the learning process would be best if he could share it with them.

Soils major Katia Keston has heard great things about Varner’s program. She says almost everyone she knows in the forestry department is emphasizing in fire ecology. “There’s tons of wildland fire jobs.”

Is prescribed fire science still developing?

Last week the Secretary of the Department of Sustainability and Environment (DSE) in Victoria, Australia told the Royal Commission that is looking into last year’s Black Saturday fires that he would not support a 4 to 6 percent increase in prescribed burning, partly because the science was still developing.

But a seven-member panel made up of fire ecologists, CSIRO fire researcher Phil Cheney, and Jerry Williams, former Chief of the U. S. Forest Service, said there is plenty of science available to support burning 5 to 10 percent of Victoria’s forests each year.

Cheney said a good prescribed fire will stop a bushfire for one to two years, and after three years will have a “profound effect” in reducing the rate of spread. For as long as 20 years embers and flame height will be reduced.

Jerry Williams said prescribed fire had an effect even in extreme conditions.

A person might say the science of prescribed burning has been developing for many centuries since indigenous people began routinely setting prescribed fires to enhance the habitat for the plants and animals they needed for survival. In 1804 and 1805 Lewis and Clark documented the use of prescribed fire by native Americans (but at least one of them had an unfortunate result). At some point we have to admit that the science has reached a level of maturity.

Abraham Lincoln said:

Things may come to those who wait…but only the things left by those who hustle.

From the DSE’s Fire Ecology web page:

Fire is a natural part of the Australian environment and has been so for millions of years. Natural ignition (lightning) and indigenous burning practices have shaped our ecosystems over tens of thousands of years.

From Bill Gabbert, February 22, 2010:

Prescribed fire, when applied wisely by experienced fire management personnel, is an essential land management tool.


via @FireInfoGirl