Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Long-term study shows acid pollution in rain decreased with emissions

17.11.2011
Emissions regulations do have an environmental impact, according to a long-term study of acidic rainfall by researchers at the University of Illinois.

The National Atmospheric Deposition Program collects rainfall samples weekly from more than 250 stations across the United States and analyzes them for pollutants. The program recently released a report detailing trends in acidic rainfall frequency and concentration over 25 years, from 1984 to 2009.

"This is the longest-term, widest-scale precipitation pollution study in the U.S. In particular, we wanted to see how the trends in the pollution and the rain correlated back to emissions regulations," said Christopher Lehmann, a researcher in the program, which is part of the Illinois State Water Survey at the U. of I. "We're seeing regulations on emissions sources having direct and positive impact to reduce pollutants in rain."

The phenomenon commonly known as "acid rain" has widespread effects not only on the ecosystem, but also on infrastructure and the economy. Polluted precipitation adversely affects forestry, fishing, agriculture and other industries. Acid also erodes structures, damaging buildings, roads and bridges.

According to the report, acidic precipitation – rain or snowfall with a pH value of 5.0 or less – decreased in both frequency and concentration over the 25-year span.

The researchers largely attribute the decrease to the amendments to the Clean Air Act in 1990 regulating emissions of sulfur dioxide and nitrogen oxide, the gases that become sulfuric and nitric acid when mixed with rain water.

"What goes up does come down," Lehmann said. "Rainfall chemistry directly correlates with air pollution. When we looked at the magnitude of the trend, we found it compared very well to the magnitude of the decrease in emissions reported by the EPA (Environmental Protection Agency)."

According to EPA data, sulfate emissions dropped more than 50 percent during the period covered by the study and nitrate emissions dropped more than 30 percent. The National Atmospheric Deposition Program report found that concentrations of corresponding acid ions in rainwater have dropped by similar magnitudes. In addition, frequency of acidic precipitation has decreased across the U.S.

"You want to make sure that the regulations you put in place are effective, that they do what they were designed to do," said David Gay, the coordinator of the deposition program. "That's why we're here. We spend a lot of money to promulgate regulations. There's a lot of concern about their impact on industry. This study shows clear, significant evidence of the direct impact of regulation."

The deposition program continues to monitor sulfur and nitrogen compounds in rain. Although acidic precipitation has decreased, it has not disappeared, particularly remaining prevalent across the eastern U.S. In addition, the program has expanded its screening and monitoring other problematic pollutants such as ammonia and mercury.

"We still have acid rain," Lehmann said. "Yes, the trend is down, and we should celebrate that, but it's still a problem. There is still progress to be made, and there are new regulations coming along to continue to reduce emissions of sulfur and nitrogen compounds."

The Illinois State Water Survey is a unit within the Prairie Research Institute at the U. of I.

Editor's notes: To reach Chris Lehman, call 217-265-8512; email clehmann@illinois.edu.

To reach David Gay, call 217-244-0462; email dgay@illinois.edu. Data are available in the public domain at the National Atmospheric Deposition Program website.

Liz Ahlberg | University of Illinois
Further information:
http://www.illinois.edu

Further reports about: EPA pesticide Illinois River Watershed Water Snake acid rain

More articles from Life Sciences:

nachricht New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg

nachricht Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>