Symposium examines aerosols from World Trade Center collapse

ARGONNE, Ill. (Sept. 5, 2003) — Contaminants from the collapse of the World Trade Center in New York City two years ago hit the city in two waves, according to researchers at the U.S. Department of Energy's Argonne National Laboratory, who are organizing a presentation on research results.

The first wave came from the initial collapse of the buildings, and featured large particulate aerosols; the second came from fires that smoldered long after the initial attack, and produced smaller particulates that were inhaled.

The environmental and health effects of the millions of pounds of debris released after the terrorist attack is the subject of a symposium led by Argonne researchers at the 226th American Chemical Society meeting Sept. 7-11 in New York City.

Argonne chemists Jeffrey Gaffney and Nancy Marley will lead Wednesday's symposium on urban aerosols and their impact.

According to Gaffney, the World Trade Center collapse led to the release of millions of pounds of debris, much of which was distributed as particles and aerosols in the cloud that hung over Manhattan. Aerosols are solid or liquid particles suspended in air. Their size ranges from 0.01 microns to several tens of microns. (There are 25,400 microns in an inch.)

Although the aerosols released during the World Trade Center collapse were both coarse and fine, those released by continuing fires under the debris were fine, combustion-related aerosols. These fine aerosols were in the air long enough and were small enough to travel deep into the lungs of humans.

Gaffney and Marley will each preside over a symposium session, in which U.S. and Canadian experts will present papers on the lifetimes, transport and removal process of aerosols; the acute and chronic health effects of exposure to fine aerosols; and the environmental impacts of aerosols.

"Researchers have measured the coarse and fine fractions of aerosols released from the World Trade Center," Gaffney said. "These were released from both the original tragedy and from fires afterward. The symposium will have lectures from researchers who have looked at both aspects of this: risk assessment and health effects."

The symposium will bring together atmospheric chemists, meteorologists, health workers and biologists to discuss what they know and what they need to know regarding the composition and transport of aerosols in urban environments, especially those from the World Trade Center collapse.

Marley and Gaffney will present a paper focusing on the chemical and physical properties of aerosols and how these properties determine the lifetimes of aerosols in the atmosphere and their movement throughout the troposphere, the lowest layer of the atmosphere.

Although learning about the effects of aerosols released from the World Trade Center collapse and fire is important, the ACS symposium has a much larger purpose. The aerosols released in the collapse signify a single episode; Gaffney hopes that the symposium will increase awareness of the possible health and climate problems that aerosols pose.

The nation’s first national laboratory, Argonne National Laboratory conducts basic and applied scientific research across a wide spectrum of disciplines, ranging from high-energy physics to climatology and biotechnology. Since 1990, Argonne has worked with more than 600 companies and numerous federal agencies and other organizations to help advance America's scientific leadership and prepare the nation for the future. Argonne is operated by the University of Chicago as part of the U.S. Department of Energy's national laboratory system. — Rhianna Wisniewski

For more information, please contact Steve McGregor (630/252-5580 or media@anl.gov) at Argonne.