Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 
Datenbankrecherche:

 

Wildfires Cause Ozone Pollution to Violate Health Standards

13.10.2008
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 manages the National Center for Atmospheric Research under sponsorship by the National Science Foundation. Any opinions, findings and conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Gabriele Pfister, NCAR Scientist
303-497-2915
pfister@ucar.edu

David Hosansky | Newswise Science News
Further information:
http://www.ucar.edu

More articles from Earth Sciences:

nachricht Oceans may be large, overlooked source of hydrogen gas
21.07.2016 | Duke University

nachricht Groundwater discharge to upper Colorado River Basin varies in response to drought
21.07.2016 | US Geological Survey

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Superschneller Internetfunk dank Terahertz-Strahlung

Wissenschaftler aus Dresden und Dublin haben einen vielversprechenden technologischen Ansatz gefunden, der Notebooks und anderen mobilen Computern in Zukunft deutlich schnellere Internet-Funkzugänge ermöglichen könnte als bisher. Die Teams am Helmholtz-Zentrum Dresden-Rossendorf (HZDR) und am irischen Trinity College Dublin brachten hauchdünne Schichten aus einer speziellen Verbindung von Mangan und Gallium dazu, sehr effizient Strahlung im sogenannten Terahertz-Frequenzbereich auszusenden. Als Sender in WLAN-Funknetzen eingesetzt, könnten die höheren Frequenzen die Datenraten zukünftiger Kommunikations-Netzwerke spürbar erhöhen.

„Wir halten diesen Ansatz für technologisch sehr interessant“, betont Dr. Michael Gensch, Leiter einer Arbeitsgruppe am HZDR, die sich mit den...

Im Focus: Newly discovered material property may lead to high temp superconductivity

Researchers at the U.S. Department of Energy's (DOE) Ames Laboratory have discovered an unusual property of purple bronze that may point to new ways to achieve high temperature superconductivity.

While studying purple bronze, a molybdenum oxide, researchers discovered an unconventional charge density wave on its surface.

Im Focus: Forschen in 15 Kilometern Höhe - Einsatz des Flugzeuges HALO wird weiter gefördert

Das moderne Höhen-Forschungsflugzeug HALO (High Altitude and Long Range Research Aircraft) wird auch in Zukunft für Projekte zur Atmosphären- und Erdsystemforschung eingesetzt werden können: Die Deutsche Forschungsgemeinschaft (DFG) bewilligte jetzt Fördergelder von mehr als 11 Millionen Euro für die nächste Phase des HALO Schwerpunktprogramms (SPP 1294) in den kommenden drei Jahren. Die Universität Leipzig ist neben der Goethe-Universität Frankfurt am Main und der Technischen Universität Dresden federführend bei diesem DFG-Schwerpunktprogramm.

Die Universität Leipzig wird von der Fördersumme knapp 6 Millionen Euro zur Durchführung von zwei Forschungsprojekten mit HALO sowie zur Deckung der hohen...

Im Focus: Mapping electromagnetic waveforms

Munich Physicists have developed a novel electron microscope that can visualize electromagnetic fields oscillating at frequencies of billions of cycles per second.

Temporally varying electromagnetic fields are the driving force behind the whole of electronics. Their polarities can change at mind-bogglingly fast rates, and...

Im Focus: Rekord in der Hochdruckforschung: 1 Terapascal erstmals erreicht und überschritten

Einem internationalen Forschungsteam um Prof. Dr. Natalia Dubrovinskaia und Prof. Dr. Leonid Dubrovinsky von der Universität Bayreuth ist es erstmals gelungen, im Labor einen Druck von 1 Terapascal (= 1.000.000.000.000 Pascal) zu erzeugen. Dieser Druck ist dreimal höher als der Druck, der im Zentrum der Erde herrscht. Die in 'Science Advances' veröffentlichte Studie eröffnet neue Forschungsmöglichkeiten für die Physik und Chemie der Festkörper, die Materialwissenschaft, die Geophysik und die Astrophysik.

Extreme Drücke und Temperaturen, die im Labor mit hoher Präzision erzeugt und kontrolliert werden, sind ideale Voraussetzungen für die Physik, Chemie und...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

IHR
JOB & KARRIERE
SERVICE
im innovations-report
in Kooperation mit academics
Veranstaltungen

Kongress für Molekulare Medizin: Krankheiten interdisziplinär verstehen und behandeln

20.07.2016 | Veranstaltungen

Ultraschnelle Kalorimetrie: Gesellschaft für thermische Analyse GEFTA lädt zur Jahrestagung

19.07.2016 | Veranstaltungen

Das neue Präventionsgesetz aktiv gestalten

19.07.2016 | Veranstaltungen

 
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Superschneller Internetfunk dank Terahertz-Strahlung

25.07.2016 | Informationstechnologie

Neue Protein-Analyse für Therapie und Diagnose von Krankheiten

25.07.2016 | Biowissenschaften Chemie

Wussten Sie, dass UV-Licht für sicheres Baden während der Sommermonate sorgt?

25.07.2016 | Energie und Elektrotechnik