Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 


Wildfires Cause Ozone Pollution to Violate Health Standards

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

David Hosansky | Newswise Science News
Further information:

More articles from Earth Sciences:

nachricht UCI and NASA document accelerated glacier melting in West Antarctica
26.10.2016 | University of California - Irvine

nachricht Ice shelf vibrations cause unusual waves in Antarctic atmosphere
25.10.2016 | American Geophysical Union

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neuartige Lichtquellen aus zweidimensionalen Materialien

Physiker der Universität Würzburg haben eine Lichtquelle hergestellt, die Doppelpacks von Photonen emittiert. Zwei-Photonen-Quellen eignen sich besonders gut, um Informationen abhörsicher zu verschlüsseln. Wesentliche Zutaten des Experiments waren ein Halbleiter-Kristall – und etwas Tesafilm.

Im Zentrum der Arbeit stehen so genannte Monolagen. Um diese „Super-Materialien“ (so das renommierte Wissenschafts-Magazin „Nature“) ist in den vergangenen...

Im Focus: Novel light sources made of 2D materials

Physicists from the University of Würzburg have designed a light source that emits photon pairs. Two-photon sources are particularly well suited for tap-proof data encryption. The experiment's key ingredients: a semiconductor crystal and some sticky tape.

So-called monolayers are at the heart of the research activities. These "super materials" (as the prestigious science magazine "Nature" puts it) have been...

Im Focus: Medica 2016: Neuer Kunststoff der TU Kaiserslautern macht medizinische Steckverbindungen sicherer

Kanülen, Spritzen oder Katheter – ein Großteil medizintechnischer Produkte besteht aus Kunststoff. Auch beim sogenannten Luer-System, einer Steckverbindung für Medizin-Schläuche, ist dies der Fall. Aufgrund von Spannungen kann es hier mit der Zeit zu Rissen kommen, wodurch etwa Luft in eine Infusionslösung geraten kann. Die Folge kann eine Embolie sein. Ingenieure der TU Kaiserslautern haben ein Luer-System mit einem neuen langlebigeren Kunststoff entwickelt. Risse breiten sich deutlich später aus. Auf der Medizintechnikmesse Medica in Düsseldorf stellen die Forscher ihre Arbeit vom 14. bis 17. November am Gemeinschaftsstand Rheinland-Pfalz (Halle 7a, Stand B06) vor.

Bei Infusionen kommt das sogenannte Luer-System zum Einsatz. Es verbindet zum Beispiel verschiedene Spritzen, Schläuche sowie Kanülen – etwa mit...

Im Focus: Mikrostrukturen mit dem Laser ätzen

Mit dem Ultrakurzpulslaser lassen sich nicht nur feine Strukturen schneiden, in einem Verbundprojekt haben Wissenschaftler untersucht, wie man damit auch Mikrostrukturen in Dünnglas erzeugen kann. Anwendungen gibt es im Analytikbereich (lab-on-a-chip), aber auch in der Elektronikbranche und im Consumer-Bereich gibt es großes Interesse.

Am Anfang dieser neuen Methode stand ein überraschender Effekt: Wenn Glas mit dem Ultrakurzpulslaser in der richtigen Weise bestrahlt wird, wird es so...

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Alle Focus-News des Innovations-reports >>>



im innovations-report
in Kooperation mit academics

Copycat: Natur als Blaupause für Innovation?

28.10.2016 | Veranstaltungen

Heilbronner Verkehrsgespräche zum Thema Logistikinnovationen am 7. November 2016

28.10.2016 | Veranstaltungen

Instandhaltung der Bauwerke an den Wasserstraßen

28.10.2016 | Veranstaltungen

Weitere VideoLinks >>>
Aktuelle Beiträge

Wenn Fettzellen die Farbe ändern

28.10.2016 | Biowissenschaften Chemie

MHH-Forscher reparieren geschädigte Blutgefäße mit Nanopartikel-Therapie

28.10.2016 | Medizin Gesundheit

Sand- oder Marmorkuchen? - Neue Einblicke zum Plattenrecycling der Erde

28.10.2016 | Geowissenschaften