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 Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen

nachricht A new indicator for marine ecosystem changes: the diatom/dinoflagellate index
21.08.2017 | Leibniz-Institut für Ostseeforschung Warnemünde

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: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>