Joint
Chemical Engineering and Env. Engr. Sci Seminar
Monday, March 22, 2004
2:30
pm
Cupples II, Room 100
“Fine
Particle Formation in Combustion Systems and Its
Implications for Human Health”
Prof. Joseph Helble
University of Connecticut
ABSTRACT OF TALK:
In 1997, the U.S. Environmental Protection Agency proposed new ambient air quality standards for particles less than 2.5 microns in size, particles generally known as PM2.5. These standards were established as a result of epidemiological studies that indicated a link between PM2.5 concentrations and elevated human mortality in the United States. Although many additional epidemiological and toxicological studies have been conducted in the past few years, scientists have yet to establish a mechanistic link between such particles and human health.
Much of the PM2.5 present in the atmosphere is derived from combustion sources, either as directly emitted primary particles or as secondary particles formed by reaction and condensation in the atmosphere. Although secondary particles often dominate the mass of PM2.5, primary particles such as carbonaceous soot and inorganic particles derived from coal, oil, biomass, and waste combustion may contain trace metals which are surface-enriched and can be carcinogenic or toxic. Measurements of both classes of particles are, however, generally made on a bulk basis, revealing little regarding their potential mechanism of interaction with the body. The research that will be discussed takes a different approach, relying upon single particle analysis of ambient particulate coupled with fundamental studies of metal transformations in combustion systems to unravel the complex formation and behavior of PM2.5. Recent studies of atmospheric particulate collected in a rural location suggest that there is little atmospheric transformation of primary particles, making control of the combustion process critical to reduction of these particles. This work will be discussed, as will our efforts to understand and model the transformations and chemistry of several of the more toxic metals in combustion systems with the goal of reducing emissions to the environment.
Biosketch:
Dr. Joseph Helble
is Professor and Department Head, Department of Chemical
Engineering and a Member of the
Environmental Engineering Program at the
University of Connecticut. He received his B.S. degree in
Chemical Engineering from Lehigh University
in 1982, and his doctoral degree in
Chemical Engineering from the Massachusetts
Institute of Technology in 1987.
Prior to joining the Univ of Connecticut in 1995, he has been an AAAS/EPA
Environmental Fellow at the USEPA and a Principal Scientist at Physical Sciences
Inc. His research interests include both
fundamental and applied studies of aerosols, with emphasis on aerosols produced
during combustion processes and nanostructured ceramics materials processing.
He has won several acclaims for his work:
Outstanding Young Faculty Award, University of
Connecticut, School of Engineering, 1999; NSF Young
Faculty CAREER Award, 1998; American Association for
the Advancement of Science (AAAS) Barnard
Environmental Science and Engineering Award, 1994; BCR/R.A.
Glenn Award for best paper, ACS Fuel Chemistry, 1989; and
PSI Technology Award 1988, 1989, 1990, 1995
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