Featured Research

from universities, journals, and other organizations

UF Technique Detects Tiny, Potentially Harmful Airborne Particles

Date:
September 25, 2000
Source:
University Of Florida
Summary:
A University of Florida professor has found a way to detect and identify extremely low levels of air pollution, a step that comes as concerns mount over the health impacts of breathing in small particles.

GAINESVILLE, Fla. --- A University of Florida professor has found a way to detect and identify extremely low levels of air pollution, a step that comes as concerns mount over the health impacts of breathing in small particles.

Related Articles


David Hahn, a UF professor of mechanical engineering, developed the technique -- a unique application of a well-known technique called Laser Induced Breakdown Spectroscopy -- with the assistance of Sandia National Laboratories in Livermore, Calif.

The process begins with an air sampler, located on a rooftop at UF's nuclear sciences building, that filters out relatively large particles and pumps the air into a nearby lab. Next, the air passes through the pulsing beam of a powerful infrared laser, and a small part of it heats up to over 35,000 degrees.

The heat vaporizes airborne molecules and particles, resulting in a flash of light and a loud crack. Although the eye can't see it, each atomic element in the vaporized sample produces a different wavelength of light. A spectrometer records these "fingerprints" and determines which elements are present, providing a real-time picture of the airborne particles.

Hahn tested his technique over the Fourth of July holiday, measuring increased airborne concentrations of magnesium, a metal used in fireworks, for as long as a week after fireworks displays ended. The increases were so small they posed no threat to human health, but the test demonstrated the technique could also detect similarly low levels of more harmful particles, such as arsenic, chromium or lead.

"The test really demonstrated the ability of this technique to measure particulate concentration levels several orders of magnitude below regulatory standards," Hahn said. "That's steadily becoming more important as people involved in pollution control seek to more accurately monitor pollution and better determine its sources."

The diameter of a human hair ranges from 50 to 100 microns, with 1 micron measuring a millionth of a meter. Hahn says his technique can measure particles as small as one-tenth of a micron, determining both mass and composition. The technique also detects particles in extremely low concentrations. With the fireworks, the technique measured week long post-fireworks magnesium concentrations at an average of 44.4 parts per trillion, compared with 2.8 parts per trillion before the fireworks.

Hahn said recent research indicates that very small particles are more dangerous than larger ones because the body's natural defenses capture and expel the larger particles, while small ones lodge in the lung cavities and cause damage over time. A major component of smog, airborne particles have been tied to asthma and other diseases. One recent study attributed 3 percent of deaths annually in Austria, France and Switzerland to particluates.

In response to such research, federal regulators increasingly have sought to study and regulate small particles. Two years ago, for example, the Environmental Protection Agency dropped its standard to regulate particulate matter down to particles as small as 2.5 microns.

Environmental officials would like to know more about what small particles the air contains -- at different times of the day and in different weather conditions -- and where the particles are coming from. The LIBS technique can help answer both questions because it picks up the presence of low levels of small particles in real time, Hahn said. That creates the potential for regulators to create much more effective, more targeted regulations, he said. "Right now, there's not a very good feel for what sources are producing what particles,"Hahn said. "If we can determine with a lot more specificity that these particles are coming from cars or plants or agriculture, then we can go after these sources and fix them."

Ben Smith, a scientist in UF's chemistry department, said Hahn's technique is one of two current techniques that can detect and measure extremely small, sparsely distributed particles. The equipment for the other technique, however, is both more complex and more expensive, costing at least $150,000 compared with about $80,000 for Hahn's technique.

"Scientists are becoming more and more interested in really small particles and how they impact human health," Smith said. "David's technique has real potential for both industrial and environmental monitoring."

###

Color or black & white photo available with this story. For information, please call News & Public Affairs photography at 352-392-9092.

Writer: Aaron Hoover, [email protected]

Source: David Hahn, 352-392-0807, [email protected]


Story Source:

The above story is based on materials provided by University Of Florida. Note: Materials may be edited for content and length.


Cite This Page:

University Of Florida. "UF Technique Detects Tiny, Potentially Harmful Airborne Particles." ScienceDaily. ScienceDaily, 25 September 2000. <www.sciencedaily.com/releases/2000/09/000913210118.htm>.
University Of Florida. (2000, September 25). UF Technique Detects Tiny, Potentially Harmful Airborne Particles. ScienceDaily. Retrieved November 24, 2014 from www.sciencedaily.com/releases/2000/09/000913210118.htm
University Of Florida. "UF Technique Detects Tiny, Potentially Harmful Airborne Particles." ScienceDaily. www.sciencedaily.com/releases/2000/09/000913210118.htm (accessed November 24, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Monday, November 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Car Park Solution for Flexible Green Energy

Car Park Solution for Flexible Green Energy

Reuters - Innovations Video Online (Nov. 24, 2014) A British solar power start-up says that by covering millions of existing car park spaces around the UK with flexible solar panels, the country's power problems could be solved. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Ebola-Hit Sierra Leone's Late Cocoa Leaves Bitter Taste

Ebola-Hit Sierra Leone's Late Cocoa Leaves Bitter Taste

AFP (Nov. 23, 2014) The arable district of Kenema in Sierra Leone -- at the centre of the Ebola outbreak in May -- has been under quarantine for three months as the cocoa harvest comes in. Duration: 01:32 Video provided by AFP
Powered by NewsLook.com
NY Gov. on Flood Prep: 'prepared for the Worst'

NY Gov. on Flood Prep: 'prepared for the Worst'

AP (Nov. 23, 2014) First came the big storm. Now comes the big melt for residents of flood-prone areas around Buffalo. New York's governor says officials are preparing for the worst as the temperature is expected to rise and potentially melt several feet of snow. (Nov. 23) Video provided by AP
Powered by NewsLook.com
Anglerfish Rarely Seen In Its Habitat Will Haunt You

Anglerfish Rarely Seen In Its Habitat Will Haunt You

Newsy (Nov. 22, 2014) For the first time Monterey Bay Aquarium recorded a video of the elusive, creepy and rarely seen anglerfish. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins