Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Gasoline worse than diesel when it comes to some types of air pollution

05.03.2012
The exhaust fumes from gasoline vehicles contribute more to the production of a specific type of air pollution-secondary organic aerosols (SOA)-than those from diesel vehicles, according to a new study by scientists from the Cooperative Institute for Research in Environmental Sciences (CIRES), NOAA's Earth System Research Laboratory (ESRL) and other colleagues.

"The surprising result we found was that it wasn't diesel engines that were contributing the most to the organic aerosols in LA," said CIRES research scientist Roya Bahreini, who led the study and also works at NOAA's ESRL. "This was contrary to what the scientific community expected."

SOAs are tiny particles that are formed in air and make up typically 40 percent to 60 percent of the aerosol mass in urban environments. This is important because fine-particle pollution can cause human health effects, such as heart or respiratory problems.

Due to the harmful nature of these particles and the fact that they can also impact the climate and can reduce visibility, scientists want to understand how they form, Bahreini said. Researchers had already established that SOAs could be formed from gases released by gasoline engines, diesel engines, and natural sources-biogenic agents from plants and trees-but they had not determined which of these sources were the most important, she said. "We needed to do the study in a location where we could separate the contribution from vehicles from that of natural emissions from vegetation," Bahreini said.

Los Angeles proved to be an ideal location. Flanked by an ocean on one side and by mountains to the north and the east, it is, in terms of air circulation, relatively isolated, Bahreini said. At this location, the scientists made three weekday and three weekend flights with the NOAA P3 research aircraft, which hosted an arsenal of instruments designed to measure different aspects of air pollution. "Each instrument tells a story about one piece of the puzzle," she said. "Where do the particles come from? How are they different from weekday to weekend, and are the sources of vehicle emissions different from weekday to weekend?" she said.

From their measurements, the scientists were able to confirm, as expected, that diesel trucks were used less during weekends, while the use of gasoline vehicles remained nearly constant throughout the week. The team then expected that the weekend levels of SOAs would take a dive from their weekday levels, Bahreini said.

But that was not what they found.

Instead the levels of the SOA particles remained relatively unchanged from their weekday levels. Because the scientists knew that the only two sources for SOA production in this location were gasoline and diesel fumes, the study's result pointed directly to gasoline as the key source.

"The contribution of diesel to SOA is almost negligible," Bahreini said. "Even being conservative, we could deduce from our results that the maximum upper limit of contribution to SOA would be 20 percent."

That leaves gasoline contributing the other 80 percent or more of the SOA, Bahreini said.

The finding will be published in Geophysical Research Letters, a journal of the American Geophysical Union. "While diesel engines emit other pollutants such as soot and nitrogen oxides, for organic aerosol pollution they are not the primary culprit," Bahreini said.

If the scientists were to apply their findings from the LA study to the rest of the world, a decrease in the emission of organic species from gasoline engines may significantly reduce SOA concentrations on a global scale as well. This suggests future research aimed at understanding ways to reduce gasoline emissions would be valuable.

Notes for Journalists
Journalists and public information officers (PIOs) of educational and scientific institutions who have registered with AGU can download a PDF copy of this paper in press by clicking on this link:

http://dx.doi.org/10.1029/2011GL050718

Or, you may order a copy of the final paper by emailing your request to Kate Ramsayer at kramsayer@agu.org. Please provide your name, the name of your publication, and your phone number.

Neither the paper nor this press release are under embargo.

Title:
"Gasoline emissions dominate over diesel in formation of secondary organic aerosol mass"
Authors:
R. Bahreini: Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Colorado, USA, and Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, Colorado, USA;

A.M. Middlebrook: Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, Colorado, USA;

J.A. de Gouw and C. Warneke: Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Colorado, USA, and Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, Colorado, USA;

M. Trainer and C.A. Brock: Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, Colorado, USA;

H. Stark: Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Colorado, USA, and Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, Colorado, USA, and now also at Aerodyne Research, Inc., Billerica, Massachusetts, USA;

S.S. Brown: Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, Colorado, USA;

W.P. Dube and J.B. Gilman: Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Colorado, USA, and Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, Colorado, USA;

K. Hall: Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Colorado, USA, and Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, Colorado, USA, and now at Nutritional Science and Toxicology Department, University of California, Berkeley, California, USA;

J.S. Holloway: Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Colorado, USA, and Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, Colorado, USA;

W.C. Kuster: Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, Colorado, USA;

A.E. Perring: Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Colorado, USA, and Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, Colorado, USA;

A.S.H. Prevot: Laboratory of Atmospheric Chemistry, Paul Scherrer Institut, Villigen, Switzerland;

J.P. Schwarz: Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Colorado, USA, and Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, Colorado, USA;

J.R. Spackman: Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Colorado, USA, and Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, Colorado, USA, and now at Science and Technology Corporation, Boulder, Colorado, USA;

S. Szidat: Department of Chemistry and Biochemistry and Oeschger Centre for Climate Change Research, University of Bern, Switzerland;

N.L. Wagner: Cooperative Institute for Research in Environmental Sciences, University of Colorado at Boulder, Colorado, USA, and Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, Colorado, USA;

R.J. Weber: School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA;

P. Zotter: Laboratory of Atmospheric Chemistry, Paul Scherrer Institut, 5232 Villigen, Switzerland;

D.D. Parrish: Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, Colorado, USA.

Contact information for the authors:
Roya Bahreini, Email: Roya.Bahreini@noaa.gov, Telephone: +1 (303) 497-4804

Kate Ramsayer | American Geophysical Union
Further information:
http://www.noaa.gov
http://www.agu.org

More articles from Earth Sciences:

nachricht Strength of tectonic plates may explain shape of the Tibetan Plateau, study finds
25.07.2017 | University of Illinois at Urbana-Champaign

nachricht NASA flights gauge summer sea ice melt in the Arctic
25.07.2017 | NASA/Goddard Space Flight Center

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Carbon Nanotubes Turn Electrical Current into Light-emitting Quasi-particles

Strong light-matter coupling in these semiconducting tubes may hold the key to electrically pumped lasers

Light-matter quasi-particles can be generated electrically in semiconducting carbon nanotubes. Material scientists and physicists from Heidelberg University...

Im Focus: Flexible proximity sensor creates smart surfaces

Fraunhofer IPA has developed a proximity sensor made from silicone and carbon nanotubes (CNT) which detects objects and determines their position. The materials and printing process used mean that the sensor is extremely flexible, economical and can be used for large surfaces. Industry and research partners can use and further develop this innovation straight away.

At first glance, the proximity sensor appears to be nothing special: a thin, elastic layer of silicone onto which black square surfaces are printed, but these...

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA mission surfs through waves in space to understand space weather

25.07.2017 | Physics and Astronomy

Strength of tectonic plates may explain shape of the Tibetan Plateau, study finds

25.07.2017 | Earth Sciences

The dense vessel network regulates formation of thrombocytes in the bone marrow

25.07.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>