Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Pitt professor says harmful byproducts of fossil fuels could be higher in urban areas

24.10.2007
3-year project applies on a large scale a method for tracing sources of nitrate in rainfall

Nitrogen oxides, the noxious byproduct of burning fossil fuels that can return to Earth in rain and snow as harmful nitrate, could taint urban water supplies and roadside waterways more than scientists and regulators realize, according to research published Oct. 20 in the online edition of the journal Environmental Science and Technology.

The three-year study, led by Emily Elliott, a professor of geology and planetary science in the University of Pittsburgh’s School of Arts and Sciences, recommends that urban areas and roadways be specifically monitored for nitrogen deposition. Nitrogen oxides can contribute to a wide variety of environmental and health ills. Nitrate—which forms when exhaust from vehicles and smokestacks oxidizes in the atmosphere—is an important contributor to acid rain and can result in stream and soil acidification, forest decline, and coastal water degradation.

Elliott and her colleagues conducted the first large-scale application of a method for determining the source of atmospheric nitrate on rain and snow samples from 33 precipitation collection sites across the Midwestern and Northeastern United States, including Pennsylvania. The sites belong to the National Atmospheric Deposition Program (NADP), a cooperative of private organizations and U.S. government agencies that analyzes precipitation for chemicals such as nitrogen, sulfur, and mercury from more than 250 sites in the United States, Puerto Rico, and the Virgin Islands.

Although vehicles are the single largest source of nitrogen oxides in this region, the researchers found by analyzing the stable isotope composition of nitrate that the primary source of nitrate in their samples were stationary sources, such as power plants and factories, located hundreds of miles away. Stationary sources pump pollutants high into the atmosphere where they can be transported for long distances before falling to the ground. Vehicle exhaust is released close to the ground and more likely deposited over shorter distances near roadways. Most monitoring sites in the NADP network are deliberately located in relatively rural settings away from urban, industrial, or agricultural centers.

The amount of nitrate pouring over the cities and busy roadways thick with vehicles could be higher than monitoring data at most NADP sites reflect, and it is possible that a significant amount of this atmospheric nitrate finds its way into sensitive water supplies, such as the Ohio River or Chesapeake Bay. In aquatic ecosystems, excess nitrate can promote an overgrowth of oxygen-consuming algae and lead to an oxygen deficiency in the water known as hypoxia. Hypoxia kills marine creatures and creates “dead zones” akin to the lifeless area of the Gulf of Mexico at the mouth of the Mississippi River. Determining the fate of major sources of nitrogen emissions is necessary to develop sound regulatory and mitigation strategies for both air and water quality, Elliott said.

“Our results highlight the need to improve our understanding of the fate of vehicle emissions—one way we can do this is by expanding monitoring networks to include more urban sites,” Elliott said, adding that both vehicle and stationary sources are major contributors to air pollution in the region studied.

Elliott said that future research will further characterize the isotopic ratios of nitrogen oxides from various emission sources and quantify how these values change during transport and with different emission controls. She is looking for industrial partners who can provide samples from smokestacks for analysis. Additionally, Elliott is interested in establishing an urban precipitation monitoring site in Pittsburgh to assess pollution sources that contribute to nitrate deposition in the Pittsburgh region.

Morgan Kelly | EurekAlert!
Further information:
http://www.pitt.edu

More articles from Ecology, The Environment and Conservation:

nachricht Safeguarding sustainability through forest certification mapping
27.06.2017 | International Institute for Applied Systems Analysis (IIASA)

nachricht Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Ecology, The Environment and Conservation >>>

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

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | 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

 
Latest News

CCNY physicists master unexplored electron property

26.07.2017 | Physics and Astronomy

Molecular microscopy illuminates molecular motor motion

26.07.2017 | Life Sciences

Large-Mouthed Fish Was Top Predator After Mass Extinction

26.07.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>