Study finds firefighters more likely to get two types of cancer

According to a recently published study, firefighters in three major municipal fire departments were more likely to be diagnosed with lung cancer and leukaemia than the general population.

Researchers examined the firefighting exposure and medical histories of 20,000 firefighters with over 1,300 cancer-related deaths and 2,600 cancer incidence cases in Chicago, Philadelphia, and San Francisco who were on duty between the years 1950 and 2009. This was one of the largest studies of its kind, and was the first to relate the time elapsed during fire runs to cancer risk.

Among eight types of cancers examined, they found slight, but statistically significant positive exposure–responses for lung cancer and leukaemia risk. The researchers wrote:

These findings contribute to the evidence of a causal association between firefighting exposures and cancer.

The study did not address the health effects on wildland firefighters who, unlike structural firefighters, do not have access to an effective breathing apparatus to provide them clean air to inhale into their lungs. There could also be significant differences between the harmful effects of vegetation smoke and that produced by materials in structure fires.

Some wildland firefighters, especially those on hand crews, are routinely exposed to smoke-filled air for hours each day when assigned to a large fire, sometimes for 14 days. At other times they can be stationed in a smoky environment 24 hours a day for weeks at a time when inversions trap smoke. This frequently occurs in northwestern California, for example on the Six Rivers, Klamath, and Shasta-Trinity National Forests. In those cases even non-firefighters working in administrative positions at the Incident Base have been adversely affected by breathing contaminated air.

As we wrote in January, 2011:

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.

Other articles on Wildfire Today tagged cancer and firefighter health.

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Long-term changes in dead wood reveal new forest dynamics

Healthy forest ecosystems need dead wood to provide important habitat for birds and mammals, but there can be too much of a good thing when dead wood fuels severe wildfires. A scientist with the U.S. Forest Service’s Pacific Southwest Research Station (PSW) compared historic and recent data from a forest in California’s central Sierra Nevada region to determine how logging and fire exclusion have changed the amounts and sizes of dead wood over time. Results were recently published in Forest Ecology and Management.

DeadwoodPSW Research Ecologist Eric Knapp and a field crew visited three research plots initially established in 1929 in old-growth, mixed conifer stands on the Stanislaus National Forest. The stands had not burned since 1889 and were logged with a variety of methods later in 1929, shortly after the first survey of the plots. In this study, Knapp and a research crew first used digitized maps to locate and re-measure all live and dead trees in the plots. They later used old plot maps to reconstruct the number and size of downed logs in the 1929 plots and also surveyed logs in the present-day plots.

The research crew compared their present-day data with those from 1929 and documented a more than nine-fold increase in the density of standing dead trees (snags) coupled with a decrease in the average diameter of the snags. Additionally, they observed nearly three times as many logs on the ground (coarse woody debris), but found a substantial decrease in the size of these logs. The majority of downed logs in the present-day re-measurement were highly decayed.

“Because larger-sized dead wood is preferred by many wildlife species, the current condition of more, smaller, and more decayed woody pieces may have a lower ratio of habitat value relative to potential fire hazard,” says Knapp. Long-term dead wood changes in these forests pose a challenge for forest managers who must balance concerns for wildlife habitat with reducing the chance for damaging wildfires.

But dead trees, like live trees, can be managed. “To restore dead wood to conditions more like those found historically will require growing larger trees and reducing the addition of dead wood from small and intermediate-sized trees,” says Knapp. “Forest thinning, through mechanical means and/or fire has been shown to slow the mortality rate of the remaining trees. In addition, using prescribed fire and low-intensity wildfire, which preferentially consume smaller and more decayed wood, would shift the balance to larger and less decayed pieces of dead wood, and help reduce fuels that contribute to uncharacteristically severe wildfires.”

To read the paper, view or download the publication from Treesearch, the U.S. Forest Service online system for sharing free, full text publications by Research and Development scientists.

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Researchers link smoke from fires to tornado intensity

Some university and federal government scientists have concluded there is a link between smoke generated by vegetation fires in Central America and the intensity of tornadoes in the southeast United States. Their research was funded primarily by the federal government, but if you want a copy of their results it will cost you $38 — rather than making the government funded product available to taxpayers as an Open Access document.

Below are some highlights of their research.

Can smoke from fires intensify tornadoes?

“Yes,” say University of Iowa researchers, who examined the effects of smoke—resulting from spring agricultural land-clearing fires in Central America—transported across the Gulf of Mexico and encountering tornado conditions already in process in the United States.

The UI study, published in the journal Geophysical Research Letters, examined the smoke impacts on a historic severe weather outbreak that occurred during the afternoon and evening of April 27, 2011. The weather event produced 122 tornadoes, resulted in 313 deaths across the southeastern United States, and is considered the most severe event of its kind since 1950.

The outbreak was caused mainly by environmental conditions leading to a large potential for tornado formation and conducive to supercells, a type of thunderstorm. However, smoke particles intensified these conditions, according to co-lead authors Gregory Carmichael, professor of chemical and biochemical engineering, and Pablo Saide, Center for Global and Regional Environmental Research (CGRER) postdoctoral fellow.

They say the smoke lowered the base of the clouds and increased wind shear, defined as wind speed variations with respect to altitude. Together, those two conditions increased the likelihood of more severe tornadoes. The effects of smoke on these conditions had not been previously described, and the study found a novel mechanism to explain these interactions.

“These results are of great importance, as it is the first study to show smoke influence on tornado severity in a real case scenario. Also, severe weather prediction centers do not include atmospheric particles and their effects in their models, and we show that they should at least consider it,” says Carmichael.

“We show the smoke influence for one tornado outbreak, so in the future we will analyze smoke effects for other outbreaks on the record to see if similar impacts are found and under which conditions they occur,” says Saide. “We also plan to work along with model developers and institutions in charge of forecasting to move forward in the implementation, testing and incorporation of these effects on operational weather prediction models.”

In order to make their findings, the researchers ran computer simulations based upon data recorded during the 2011 event. One type of simulation included smoke and its effect on solar radiation and clouds, while the other omitted smoke. In fact, the simulation including the smoke resulted in a lowered cloud base and greater wind shear.

Future studies will focus on gaining a better understanding of the impacts of smoke on near-storm environments and tornado occurrence, intensity, and longevity, adds Carmichael, who also serves as director of the Iowa Informatics Initiative and co-director of CGRER.

Paper co-authors are Scott Spak ofthe UI Departments of Urban and Regional Planning and Civil and Environmental Engineering; Bradley Pierce and Andrew Heidinger of National Oceanic and Atmospheric Administration Satellite and Information Service Center for Satellite Applications and Research; Jason Otkin and Todd Schaack of the Cooperative Institute for Meteorological Satellite Studies, University of Wisconsin-Madison; Arlindo da Silva of NASA Goddard Space Flight Center; and Meloë Kacenelenbogen and Jens Redemann of NASA.

The paper “Central American biomass burning smoke can increase tornado severity in the U.S.” can be found online [for a fee of up to $38].

The research was funded by grants from NASA, U.S. Environmental Protection Agency, National Institutes of Health, National Oceanic and Atmospheric Administration, and the Fulbright-CONICYT scholarship program in Chile.

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National Ecological Observatory Network studies the High Park Fire

This video was published June 6, 2013.
In response to one of the worst wildfires in Colorado history, scientists from the Warner College of Natural Resources at Colorado State University (CSU) are leading a first of its kind, large-scale wildfire impact study on the High Park Fire in partnership with Colorado’s newest research facility, the National Ecological Observatory Network (NEON). The study will provide critical data to communities still grappling with how to respond to major water quality, erosion and ecosystem restoration issues in an area spanning more than 136 square miles.

Supported by a National Science Foundation (NSF) RAPID grant, the collaboration will integrate airborne remote sensing data collected by NEON’s Airborne Observation Platform (AOP) with ground-based data from a targeted field campaign conducted by CSU researchers. RAPID, short for Grants for Rapid Response Research, are used for proposals having a real urgency, including quick-response research on natural disasters. This effort is the first time a comprehensive airborne remote sensing system of this caliber will be used to enhance research on wildfire causes and impacts. The system will be able to detect remaining vegetation, identify plant species, ash cover, soil properties and other details to help illustrate how the fire burned–over the span of the entire fire scar.

“The NEON Airborne Observatory is transforming research by providing data to researchers and resource managers at temporal and geographic scales that could not previously be captured,” says Elizabeth Blood, NSF program director for NEON. “By combining ground measurements with data gathered from cutting-edge instruments in NEON airplanes, scientists are gathering potentially pivotal information about small scale and large scale processes that affect the spread of fires through forests and subsequent forest recovery.”

NEON will be to ecological health what an EKG is to heart health. Like an EKG generates snapshots of heart health by measuring heart activity at strategic locations on a patient’s body, NEON will generate snapshots of ecosystem health by measuring ecological activity at strategic locations throughout the U.S. Resulting ecological data will enable scientists to generate the first apples-to-apples comparisons of ecosystem health throughout large regions of the U.S. and the entire country over multiple decades.

Some of NEON’s data collection and educational operations have already begun, and others will begin incrementally until NEON becomes fully functional in 2017. All of NEON’s data, synthesized data products and associated educational materials will be made freely available on the Internet. These materials will thereby provide grist for groundbreaking analyses and educational activities by researchers, students, decision-makers, educators and the public.

NEON will be fully operational for some 30 years.

Articles at Wildfire Today tagged “High Park Fire”.

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Researchers: insects and drought more of a threat to forests than wildfires

custer engine highland fire

Custer FD’s Engine 6 at the Highland Fire west of Custer, SD, July 1, 2012. Photo by Bill Gabbert.

New research shows that the most significant current threat to western dry forests is from insect outbreaks and droughts, not wildfires; and historically abundant small trees offer the greatest hope for forest survival and recovery after these events. Dry forests are low-elevation western forests with tall pines. The study used government records of insect and wildfire damage to compare current threats to dry forests and used records from land surveys conducted in the late-1800s to understand how dry forests persisted for thousands of years in spite of insect outbreaks, droughts, and fires. These forests persisted, this study suggests, by having both young and old trees that together provided bet-hedging.

Data on recent threats to dry forests used government maps of insect outbreaks and wildfires from 1999-2012 across 64 million acres of western dry forests or 80% of the total dry-forest area. “When comparing the rates of insect outbreaks and wildfire over the past fourteen years, we were surprised to discover insect outbreaks impacted 5 to 7 times the area that wildfire did.” said Dr. Mark Williams, a co-author of the study and recent PhD graduate of the University of Wyoming’s Program in Ecology. “In contrast, restoration efforts to increase resilience of dry forests to changing climate focus primarily on threats from wildfire. Our work suggests that impacts from insect pests should be considered with greater weight when formulating restoration prescriptions.”

To understand how forests were resilient to multiple disturbances in the past, the researchers utilized historical data which included 45,171 tree sizes measured along 13,900 section-lines traversed by land surveyors in about 4.2 million acres of dry forests in Arizona, California, Colorado, and Oregon in the late-1800s.

“The late-1800s land surveys provide us with a spatially extensive and detailed view of how these dry forests persisted through unpredictable episodes of insect outbreaks, droughts, and wildfires” said Dr. William Baker, a co-author of the study and Professor Emeritus in the Program in Ecology and Department of Geography at the University of Wyoming. “What we see from the surveys is that dry forests historically had many large trees, that often survived wildfires, but even more small trees that were less prone to be killed during insect outbreaks and droughts. The combination of abundant youth and older trees provided bet-hedging insurance that allowed these forests to survive and recover regardless of whether an insect outbreak, drought, or wildfire occurred. These unpredictable events may increase with global warming.”

The study’s findings suggest current programs that remove most small trees to lower the intensity of wildfires in dry forests and restore large trees lost to logging, may reduce forest resilience to the larger threats from insect outbreaks and droughts. “Using historical forests as a guide, our study suggests we may want to modify our restoration and management programs so they do not put all our eggs in one basket, but instead hedge our bets by keeping both large trees and abundant small ones” said Dr. Baker.

Key findings:

  • Over the last fourteen years, insect outbreaks have impacted 5 to 7 times more dry forests than have wildfires.
  • Historically, dry forests had large trees, but were numerically dominated by small trees, 52-92% of total trees.
  • The variable structure of past forests provided bet-hedging insurance against multiple disturbances and continued persistence. Removing most small trees for modern restoration treatments may reduce the resilience of these forests.

The study was published Open Access online in the international scientific journal, Frontiers in Ecology and Evolution and is freely available to download on their website.

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New research outlines global threat of smoldering peat fires

peat fire

A smoldering peatland fire in shown in a drained lakebed in Florida, where the fire smoldered for months and consumed several feet of organic soil in some places. Credit: Desert Research Institute, the environmental research arm of the Nevada System of Higher Education.

“The scary thing is future climate change may … dry out peatlands. If peatlands become more vulnerable to fire worldwide, this will exacerbate climate change in an unending loop.”  Guido R. van der Werf

Six researchers have written a paper about how climate change is expected to increase the number of peat fires worldwide. This is disturbing for a number of reasons, including the health effects of the additional smoke that humans must breathe, and the additional carbon in the atmosphere may “exacerbate climate change in an unending loop.”

The researchers — Merritt R. Turetsky, Brian Benscoter, Susan Page, Guillermo Rein, Guido R. van der Werf, and Adam Watts — all work for universities. Even though the funding was supplied by five government agencies, if you want to read their paper at Nature Geoscience it will cost you between $5 and $32. Open Access is apparently not a priority for the universities and government agencies that are responsible for this important taxpayer funded research. The agencies that funded the research, other than the universities that employ the scientists, are National Science Foundation (NSF), NASA, The European Research Council, the Natural Sciences and Engineering Research Council of Canada, and the Desert Research Institute’s Division of Atmospheric Sciences (the environmental research arm of the Nevada System of Higher Education).

Government agencies should not fund research unless there is a guarantee that the results will be immediately, freely, and easily available on the internet.

Below is an article about their findings, supplied by the Desert Research Institute, the environmental research arm of the Nevada System of Higher Education, the employer of Mr. Watts.

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The natural disaster plays out like a movie script – ash falling from the sky, thick smoke shutting down airports and businesses across the globe, and uncontrollable fires burning for days and weeks. But this is not from a script; rather, it is a vivid description of a future climate change scenario in which the Earth’s peat-rich regions become more susceptible to drying and burning.

New research published this week in the journal Nature Geoscience, co-authored by Adam Watts, a fire ecologist at Nevada’s Desert Research Institute (DRI) and deputy director of DRI’s Climate, Ecosystems, Fire and Applications Program, outlines the threat of drying peatlands (also known as mires) across the globe and their increased vulnerability to fire and carbon loss.

Peatlands – which make up around three-percent of the Earth’s land surface and store approximately 25-percent of the world’s soil carbon – are deposits of plant material and organic matter mixed with soil that is too wet to support high levels of decomposition. Peatlands are found on all seven continents.

Already the largest fires on Earth in terms of their carbon footprint, these smoldering fires burn through thick layers of peat, built up over thousands of years, which blanket the ground in ecosystems ranging from the tropics to the arctic.

“When people picture a forest fire, they probably think of flames licking up into tree tops, and animals trying to escape,” said the study’s lead author Merritt Turetsky, a professor of Integrative Biology at University of Guelph in Ontario, Canada. “But peat fires tend to be creeping ground fires. They can burn for days and weeks, even under relatively wet conditions. They lack the drama of flames, but they produce a lot of smoke.”

That smoke contains large amounts of carbon and makes peat fires dangerous to human health. It can worsen air quality and even trigger asthma and other respiratory problems.

“In addition to the amount of carbon released, the types of emissions also can make smoldering fires of greater concern than fires where most of the combustion takes place in flames,” said Watts, who is studying the emissions from burning peat and many other types of organic fuels with his DRI colleagues to determine their potential effects in the atmosphere and on our global climate.

“Peat fires are an example of wildfires having effects far beyond the areas where they occur, and these effects can last for a very long time,” he added.

Turetsky and former University of Guelph post-doctoral researcher Brian Benscoter teamed up with temperate and tropical fire scientists to summarize what is known about peat fires, from massive lightning-ignited fires that burn large areas of the boreal region to tropical fires often triggered by human activity.

“The tropical peatlands in Southeast Asia are a clear demonstration of how human activity can alter the natural relationships between ecosystems and fire,” explained Susan Page, a University of Leicester professor and co-author on the study. “Tropical peatlands are highly resistant to natural fires, but in recent decades, humans have drained peatlands for plantation agriculture. People cause the deep layers of peat to dry out, and also greatly increase the number of fire ignitions. It’s a double threat.”

This causes a host of problems, including health issues, airport and school closures, and political tensions.

The paper concludes that almost all peat-rich regions will become more susceptible to drying and burning with a changing climate. The authors also note that the ecology of peat fires and the role of peat fires in long-term Earth system processes need to be explored more thoroughly in future research.

“Thanks to satellite data, we are fully aware of the vast scale of burning in drained peatlands, mostly in Indonesia,” said co-author Guido van der Werf, a professor at Amsterdam’s VU University. “The scary thing,” Werf added,” is future climate change may actually do the same thing: dry out peatlands. If peatlands become more vulnerable to fire worldwide, this will exacerbate climate change in an unending loop.”

This research was supported by the National Science Foundation (NSF), NASA, The European Research Council, the Natural Sciences and Engineering Research Council of Canada, and the Desert Research Institute’s Division of Atmospheric Sciences.

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