Scientists have underestimated the dangers of nitrogen oxide emissions, according to a University of Innsbruck study. Traffic in Europe has contributed to nitrogen oxide pollution to rise by up to a factor of four.
The nitrogen cycle, a process during which atmospheric nitrogen and nitrogenous elements are changed into materials that can be used by plants, is important for monitoring ozone in the lower atmosphere. Sudden industrialization and changes in agriculture have contributed to a growth of atmospheric nitrogen oxide in the 20th century.
Nitrogen oxide pollution is now unfolding as the chief environmental issue in Europe. Nitrogen oxide is characterized as a dangerous air pollutant that also causes ground level ozone to increase. While multiple European cities are already violating EU safety regulations regarding nitrogen oxide, this occurrence is not limited to urban regions anymore.
Rural areas have levels of nitrogen oxide that match those of urban areas. In Innsbruck, an Austrian city where the study was conducted, the standard level of nitrogen oxide is 36 times higher than the recent emission policy described in the Clean Air Act in the United States.
These violations in Europe can be traced back to the popularity of diesel cars: 55 percent of recently registered vehicles in the European Union were activated by diesel fuel in 2012, with 30 percent of drivers in Germany owning a diesel car and 70 percent in France.
The exhaust from the gasoline-activated engines ruin the ozone layer, since there is an extreme air-fuel ratio during combustion.
Scientists led by Thomas Karl from the Institute of Atmospheric and Cryospheric Sciences at the University of Innsbruck set out to analyze the major polluters of nitrogen oxide emissions.
The chosen location of the study was Innsbruck at the center of the Inn Valley, which sits as one of the most crucial Alpine crossing positions for the movement of goods between Northern and Southern Europe. An annual 6 million vehicles pass through the valley, which is about 10 kilometers wide and enclosed by mountain ranges about 2.5 kilometers high.
The team used the eddy-covariance method, or a procedure that measures and tallies vertical rough fluctuation within atmospheric border coverings. This method enabled the scientists to track the level of gases in the air. This helped them to discover the emissions in metropolitan regions.
“We continuously measure the concentration of carbon dioxide, nitrogen oxide and volatile organic compounds at our urban observatory in Innsbruck. We record 36,000 data points per hour,” Karl explained.
The team received data from the statistical procedures. The data was taken from a radius of approximately one kilometer of the evaluation site.
The results revealed that there was a link between carbon dioxide and nitrogen oxide ratios. The amount of nitrogen oxide emissions correlative to carbon dioxide from road traffic was 50 to 70 percent higher.
Varying combustion and exhaust produced notably higher nitrogen oxide/carbon dioxide emission correlation for diesel-generated cars than for gasoline. The typical present-day Austrian car released a factor of eight to 10 more nitrogen oxide than Euro emission regulations. When considering the differences in fuel economy between European and U.S. cars, this Austrian car factor reveals that there are more nitrogen oxide emissions per traveled distance than the up-to-date established emission regulations.
Scientists also investigated differences in weekend and weekday traffic. In Austria, heavy-duty vehicle traffic is prohibited between 4 p.m. on Saturday and 11 p.m. on Sunday and on public holidays between midnight and 11 p.m.
The data illustrated that there were fewer vehicles on Saturdays than on weekdays, as levels of benzene and toluene, two liquid chemicals that are used to make fuel for automobiles, dropped.
As a result, local ozone creation can rise by 39 to 70 percent when nitrogen oxide decreases in Innsbruck. It will be reduced between 70 to 85 percent when carbon dioxide is reduced.
By tracking carbon dioxide in the atmosphere, scientists were able to explain why the levels of nitrogen oxide barely decreased since the Euro emission standards were created in Central Europe.
While diesel cars may withstand carbon dioxide releases through superior fuel economy better than gasoline activated cars, they contribute to an extensive nitrogen oxide pollution issue in Europe.
Because of the increasing nitrogen oxide pollution, driving prohibitions and speed limits were added to the Austrian Clean Air Protection Act.
In the future, scientists wish to examine the effects of the highways in the Lower Inn Valley, conduct studies in Innsbruck during the winter months and inspect the effect of agricultural events.