 |
|
Wildfires Cause Ozone Pollution to Violate Health Standards, New Study Shows
October 10, 2008BOULDER-Wildfires can boost ozone pollution to levels that violate U.S. health standards, a new study concludes. The research, by scientists at the National Center for Atmospheric Research (NCAR), focused on California wildfires in 2007, finding that they repeatedly caused ground-level ozone to spike to unhealthy levels across a broad area, including much of rural California as well as neighboring Nevada.
The study was published today in Geophysical Research Letters. It was funded by NASA and by the National Science Foundation, which sponsors NCAR.
"It's important to understand the health impacts of wildfires," says NCAR scientist Gabriele Pfister, the lead author. "Ozone can hit unhealthy levels even in places where people don't see smoke."
Although scientists have long known that wildfires can affect air quality by emitting particles and gases into the air, there has been little research to quantify the impacts. Fires worsen ozone levels by releasing nitrogen oxides and hydrocarbons, which can form ozone near the fire or far downwind as a result of chemical reactions in sunlight.
The researchers, using a combination of computer models and ground-level measurements, studied intense California wildfires that broke out in September and October of 2007. They found that ozone was three times more likely to violate safe levels when fire plumes blew into a region than when no plumes were present.
At the time of the wildfires, the public health standard for ozone set by the Environmental Protection Agency (EPA) was 0.08 parts per million over an eight-hour period. The EPA has since tightened the standard to 0.075 parts per million. Under the stricter standard, the number of violations would have nearly doubled.
While ozone in the stratosphere benefits life on Earth by blocking ultraviolet radiation from the Sun, ozone in the lower atmosphere can trigger a number of health problems. These range from coughing and throat irritation to more serious problems, such as aggravation of asthma, bronchitis, and emphysema. Ground-level ozone pollution also damages crops and other plants.
"Wildfires are expected to worsen in the future, especially as our climate grows warmer," Pfister says. "But we are only now beginning to understand their potential impacts on people and ecosystems, not only nearby but also potentially far downwind."
Rural impacts
The unhealthy levels of ozone the researchers detected occurred mostly in rural areas. This finding may be a result of the computer modeling, which lacked the fine detail to zoom in on relatively compact urban areas. However, the authors also speculate that wildfire emissions have a greater impact on ozone levels in the countryside than on cities. The reason has to do with chemistry. Cities tend to have more nitrogen dioxide, a pollutant that can, at high levels, reduce the efficiency with which ozone is produced or even destroy ozone.
"The impact of wildfires on ozone in suburban and rural areas, far from urban sources of pollution, was quite noticeable," says NCAR scientist Christine Wiedinmyer, a co-author of the paper.
The paper notes that ozone levels would likely have been even greater except that Santa Ana winds in October blew wildfire plumes over the Pacific Ocean, safely away from populated areas.
Tracking the emissions
To measure the impact of the fires on ozone formation, the researchers turned to a pair of computer models developed at NCAR. With the first one, a specialized fire model, they estimated the amount of vegetation burned and resulting emissions of nitrous oxides, sulfur dioxide, and other pollutants. Those results went into a global air chemistry model that simulated the movement of the emissions and evolving chemistry and tracked the resulting formation of ozone as the fire plumes spread downwind.
The scientists compared their modeling results with ozone measurements from a network of EPA ground stations at various sites in California. This enabled them to determine both the number of ozone violations and the extent to which the wildfires contributed to those violations. It also enabled them to verify the accuracy of the model.
The University Corporation for Atmospheric Research
Although scientists have long known that wildfires can affect air quality by emitting particles and gases into the air, there has been little research to quantify the impacts. Fires worsen ozone levels by releasing nitrogen oxides and hydrocarbons, which can form ozone near the fire or far downwind as a result of chemical reactions in sunlight.
The researchers, using a combination of computer models and ground-level measurements, studied intense California wildfires that broke out in September and October of 2007. They found that ozone was three times more likely to violate safe levels when fire plumes blew into a region than when no plumes were present.
At the time of the wildfires, the public health standard for ozone set by the Environmental Protection Agency (EPA) was 0.08 parts per million over an eight-hour period. The EPA has since tightened the standard to 0.075 parts per million. Under the stricter standard, the number of violations would have nearly doubled.
While ozone in the stratosphere benefits life on Earth by blocking ultraviolet radiation from the Sun, ozone in the lower atmosphere can trigger a number of health problems. These range from coughing and throat irritation to more serious problems, such as aggravation of asthma, bronchitis, and emphysema. Ground-level ozone pollution also damages crops and other plants.
"Wildfires are expected to worsen in the future, especially as our climate grows warmer," Pfister says. "But we are only now beginning to understand their potential impacts on people and ecosystems, not only nearby but also potentially far downwind."
Rural impacts
The unhealthy levels of ozone the researchers detected occurred mostly in rural areas. This finding may be a result of the computer modeling, which lacked the fine detail to zoom in on relatively compact urban areas. However, the authors also speculate that wildfire emissions have a greater impact on ozone levels in the countryside than on cities. The reason has to do with chemistry. Cities tend to have more nitrogen dioxide, a pollutant that can, at high levels, reduce the efficiency with which ozone is produced or even destroy ozone.
"The impact of wildfires on ozone in suburban and rural areas, far from urban sources of pollution, was quite noticeable," says NCAR scientist Christine Wiedinmyer, a co-author of the paper.
The paper notes that ozone levels would likely have been even greater except that Santa Ana winds in October blew wildfire plumes over the Pacific Ocean, safely away from populated areas.
Tracking the emissions
To measure the impact of the fires on ozone formation, the researchers turned to a pair of computer models developed at NCAR. With the first one, a specialized fire model, they estimated the amount of vegetation burned and resulting emissions of nitrous oxides, sulfur dioxide, and other pollutants. Those results went into a global air chemistry model that simulated the movement of the emissions and evolving chemistry and tracked the resulting formation of ozone as the fire plumes spread downwind.
The scientists compared their modeling results with ozone measurements from a network of EPA ground stations at various sites in California. This enabled them to determine both the number of ozone violations and the extent to which the wildfires contributed to those violations. It also enabled them to verify the accuracy of the model.
The University Corporation for Atmospheric Research
Ozone Current Events and Ozone News RSSNew Satellite Data Reveal Impact of Olympic Pollution Controls
Chinese government regulators had clearer skies and easier breathing in mind in the summer of 2008 when they temporarily shuttered some factories and banished many cars in a pre-Olympic sprint to clean up Beijing's air. And that's what they got.
Chemist tames longstanding electron computation problem
When the University of Chicago's David Mazziotti talks about chemistry, perhaps he is thinking about how the behavior of all of the electrons in a molecule can be anticipated from the behavior of just two of its electrons.
Smokers see decline in ability to smell, rise in laryngitis, and upper airway issues
As Americans prepare for a day without cigarettes and tobacco products as part of the American Cancer Society Great American Smokeout (R) (November 20), new research gives them more reasons to extend that break to a lifetime.
Potent greenhouse gas more prevalent in atmosphere than previously assumed
A powerful greenhouse gas is at least four times more prevalent in the atmosphere than previously estimated, according to a team of researchers at Scripps Institution of Oceanography at UC San Diego.
2008 ozone hole larger than last year
The 2008 ozone hole - a thinning in the ozone layer over Antarctica - is larger both in size and ozone loss than 2007 but is not as large as 2006.
International Field Campaign examines impact of beetle kill on Rocky Mountain weather, air quality
Mountain pine beetles appear to be doing more than killing large swaths of forests in the Rocky Mountains. Scientists suspect they are also altering local weather patterns and air quality.
Pine Bark Beetles Affecting More than Forests
Pine bark beetles appear to be doing more than killing large swaths of forests in the Rocky Mountains. Scientists suspect they are also altering local weather patterns and air quality.
IMPACTS: On the Threshold of Abrupt Climate Changes
Abrupt climate change is a potential menace that hasn't received much attention. That's about to change. Through its Climate Change Prediction Program, the U.S. Department of Energy's Office of Biological and Environmental Research (OBER) recently launched IMPACTS - Investigation of the Magnitudes and Probabilities of Abrupt Climate Transitions - a program led by William Collins of Berkeley Lab's Earth Sciences Division (ESD) that brings together six national laboratories to attack the problem of abrupt climate change, or ACC.
Pollution, everyday allergens, may be sources of laryngitis
Everyday exposure to environmental tobacco smoke, allergens, and air pollution may be the root of chronic cases of laryngitis, says new research presented at the 2008 American Academy of Otolaryngology - Head and Neck Surgery Foundation (AAO-HNSF) Annual Meeting & OTO EXPO in Chicago, IL.
Breaking harmful bonds
Everybody loves the way breakfast eggs conveniently slide off of Teflon without leaving any pesky pieces of egg in the pan. Indeed, the carbon-fluorine bond at the heart of Teflon cookware is so helpful we also use it in clothing, lubricants, refrigerants, anesthetics, semiconductors, and even blood substitutes.
More Ozone Current Events and Ozone News Articles
 | OZONE A New Medical Drug by Velio Bocci Oxygen-ozone therapy is a complementary approach less known than homeopathy and acupuncture because it has come of age only three decades ago. This book clarifies that, in the often nebulous field of natural medicine, the biological bases of ozone therapy are totally in line with classic biochemical, physiological and pharmacological knowledge. Ozone is an oxidising molecule, a sort of... |
 | Ozone Diplomacy: New Directions in Safeguarding the Planet, Enlarged Edition by Richard Elliot Benedick Hailed in the Foreign Service Journal as "a landmark book that should command the attention of every serious student of American diplomacy, international environmental issues, or the art of negotiation," and cited in Nature for its "worthwhile insights on the harnessing of science and diplomacy," the first edition of Ozone Diplomacy offered an insider's view of the politics, economics, science,... |
 | Flood Your Body with Oxygen by Ed Mccabe Flood Your Body With Oxygen is "Mr. Oxygen" Ed McCabe's follow-up to his best-seller Oxygen Therapies, and is the seminal work on the subject and encompasses its' entirety. DISEASES CAN'T LIVE IN ACTIVE OXYGEN. Proven safe solutions for all the major problems facing our health, our animals, our food supply, and our environment are explained simply and backed up with testimonials and industry and... |
| Surprise! by Lucy Ozone | |
 | Oxygen-Ozone Therapy: A Critical Evaluation by V. Bocci Univ. of Siena, Italy. Explains the fundamental basis of ozonetherapy. For scientists, clinicians, and patients. Argues that scientists and clinicians should abandon their prejudice and consider the profound difference between the endogenous oxidative stress and the new concept of ozonetherapeutic... |
 | Stratospheric Ozone Depletion by Larry Parker, Wayne A. Morrissey For two decades, scientists have been warning that chlorofluorocarbons (CFCs) and halons (bromine-containing fluorocarbons) may deplete the stratospheric ozone shield that screens out some of the Sun's harmful ultraviolet rays and thus regulates the amounts which reach the Earth's surface. CFCs have been used as refrigerants, solvents, foam blowing agents, and outside the United States, as... |
 | Ozone: The Revolution In Dentistry |
| The Use of Ozone in Medicine: A Practical Handbook by Renate Viebahn | |
| Ozone Friendly Biodegradable Joke by Teresa Green | |
 | Tropospheric Ozone: Human Health and Agricultural Impacts by David McKee Tropospheric ozone has long been recognized as a major environmental concern. Levels of ozone concentration have grown dramatically and the effects of ozone exposure have been examined in virtually thousands of studies worldwide. This timely new reference presents the state of the art in ozone regulation, human health effects, agricultural implications, and the economics of ozone reduction.... |
| © 2009 BrightSurf.com |