. Earth Science News .

Long-term study shows acid pollution in rain decreased with emissions
by Staff Writers
Champaign, IL (SPX) Nov 18, 2011

The mean concentration of sulfuric acid ions in rainwater in 1985, as measured by the National Atmospheric Deposition Program's network of collection sites across the United States. Credit: National Atmospheric Deposition Program, Illinois State Water Survey.

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."

Related Links
University of Illinois at Urbana-Champaign
Water News - Science, Technology and Politics

Get Our Free Newsletters Via Email
Buy Advertising Editorial Enquiries


. Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Climate change threatens Nile, Limpopo rivers: study
Johannesburg (AFP) Nov 14, 2011
Rising global temperatures and shifting rainfall patterns could affect water flows on Africa's mighty Nile and Limpopo rivers, an agricultural research group said Monday. The Consultative Group on International Agricultural Research, a global think-tank, warned the changes could have major effects for countries that share the rivers - raising the risk of conflicts erupting over water use, a ... read more

Haiti leader moves towards restoring army

Chemical plant blast kills 14 in China

Fukushima 'not obstacle' to Japan business: PM

Rescue service orders helicopters

Hungary likely source of elevated radioactivity levels: IAEA

New 'smart' material could help tap medical potential of tissue-penetrating light

Amazon sells Kindle Fire below cost: research firm

World's lightest material invented

Tuna fishing countries vow to protect shark

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

At least 141 workers fired at site for Brazil's Amazon dam

La Nina returns, but weaker impact seen: UN weather agency

Gamburtsev Mountains enigma unraveled in East Antarctica

Prof Helping To Unravel Causes Of Ice Age Extinctions

International Team to Drill Beneath Massive Antarctic Ice Shelf

Preparing for a thaw: How Arctic microbes respond to a warming world

Asian thirst for wine feeds new investment market

Evidence supports ban on growth promotion use of antibiotics in farming

China launches farm project in Bulgaria

Warnings as sustainable palm oil effort falters

Fears for ancient Thai temples as floods recede

Floods help Thai army clean up reputation

Quake hits eastern Japan, nuclear plant stable

Supervolcanoes: Not a threat for 2012

China says Mugabe 'old friend' as Zimbabwe head visits

Nobel laureate Gbowee to lead Liberian peace initiative

Sudan beefing up border air strike capacity: monitors

US condemns bombing by Sudan Armed Forces

Moderate drinking and cardiovascular health: here comes the beer

Is a stranger genetically wired to be trustworthy? You'll know in 20 seconds

Live longer with fewer calories

Asian couples rush to wed on auspicious date


The content herein, unless otherwise known to be public domain, are Copyright 1995-2011 - Space Media Network. AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement