• Zarbl, Helmut (PI)
  • Willey, James (PI)
  • Howard, Jack (PI)
  • Zarbl, Helmut (PI)
  • Thilly, William (PI)
  • Sarofim, Adel (PI)
  • Thilly, William (PI)
  • Tannenbaum, Steven (PI)
  • Lafleur, Arthur (PI)
  • Busby, William (PI)
  • Utell, Mark (PI)
  • Sarofim, Adel (PI)
  • Thilly, William (PI)
  • Tannenbaum, Steven (PI)
  • Lafleur, Arthur (PI)
  • Busby, William (PI)
  • Utell, Mark (PI)
  • Sarofim, Adel (PI)
  • Tannenbaum, Steven (PI)
  • Lafleur, Arthur (PI)
  • Busby, William (PI)
  • Utell, Mark (PI)

Project Details


The objectives of the proposed research are to determine the most
important mutagenic chemical compounds present in atmospheric particulate
matter and in urban source effluents using newly developed human cell
assays. The results on concentrations of the most important mutagens in
the ambient organic aerosols and source samples will be used to track
those compounds back to their source. The research initially will involve
ambient organic particulate matter samples representative of the full
range of seasonal conditions and spatial pollutant gradients found in the
heavily polluted Los Angeles area atmosphere. Bioassay-directed chemical
analysis will be used to determine the identity of the most important
mutagens. An integral part of the study will be the determination of the
effect of atmospheric transformations on the composition and
concentrations of the most important mutagens. One measure of atmospheric
transformation is the difference between the observed atmospheric
concentrations of the most important mutagens and the values calculated
from the contributions of the primary sources. The calculated values will
be obtained using either atmospheric transport models that follow
dispersion from the sources or molecular tracer techniques. Another
measure is provided by the distribution of the primary mutagens between
the different size fractions of the fine aerosols in the atmosphere.
Particles in the 0.05 to 0.5 mum size range are representative of primary
effluents whereas particles in the size range of 0.5 to 2.0 mum have
undergone atmospheric reactions and agglomeration in the atmosphere. An
understanding of the partitioning of PAH and its atmospheric
transformation products is important for the interpretation of the data on
the distribution of the most important mutagen between the different size
fractions. Preliminary results with human cell assays on fractions,
obtained by gradient elution liquid chromatography, of extracts from
particles collected in Los Angeles, CA, Saint Louis, MO, and Washington,
DC, show that polycyclic aromatic hydrocarbons (PAH) and their nitro
derivatives are two classes of compounds that account for a significant
portion of the observed mutations. While the PAH are emitted primarily by
combustion sources, the nitro-substituted PAH may be either present in the
primary effluents from the combustors or be produced from combustion-
generated PAH by atmospheric reactions. The mechanism of formation of PAH
and its derivatives will be studied in order to help distinguish between
the combustion and atmospheric pathways to nitro-substituted PAH as well
as to explain the observation of high specific mutagenicity (mutant
fraction per microgram of organic carbon) of certain combustion sources
(e.g., natural gas appliances). Key to the mechanism is the measurement
of the PAH radicals in flames. The transferability of the results from
Los Angeles to other locations, after due allowance is made for
differences in the magnitudes of the major sources of organic emission and
for differences in dispersion and atmospheric chemistry, will be assessed
by studying samples from two locations in each of Rochester, NY, and
Woburn, MA, and selected indoor samples.
Effective start/end date1/1/017/31/03


  • Analytical Chemistry
  • Pollution
  • Transplantation
  • Genetics
  • Spectroscopy
  • Oncology
  • Cancer Research
  • Pulmonary and Respiratory Medicine
  • Cell Biology
  • Toxicology
  • Pharmacology
  • Atmospheric Science