The Atmospheric Chemistry of Particulate-bound Polycylcic Aromatic

210 Pages·2005·8.05 MB·English

AN ABSTRACT OF THE DISSERTATION OF
Narumol Jariyasopit for the degree of Doctor of Philosophy in Chemistry presented on
May 17, 2013.
Title: The Atmospheric Chemistry of Particulate-bound Polycyclic Aromatic
Hydrocarbons: Concentration, Prediction, Laboratory Studies, and Mutagenicity

Abstract approved:

________________________________________________________________________
Staci L. Massey Simonich

The trans-Pacific atmospheric transport of particulate matter (PM)-bound
polycyclic aromatic hydrocarbons (PAHs) to remote sites in western North America has
been well documented and has triggered research questions regarding to atmospheric
transformation of PM-bound PAHs and the potential impacts on human health from their
inhalation exposure. In this dissertation, field measurements, theoretical studies,
laboratory experiments, and mutagenicity studies were used to begin the address the
questions as to whether PM-bound PAHs undergo atmospheric transformation into
mutagenic nitro-PAHs (NPAHs) during trans-Pacific atmospheric transport. PM extracts
were tested in the Salmonella mutagenicity assay, using Salmonella typhimurium strain
TA98 (with and without metabolic activation), to determine the mutagenic activities in
relation to the chemical composition of the extracts.
The sampling of atmospheric PM with diameter < 2.5 µm (PM ) before, during,
2.5
and after the Olympic Games 2008 in Beijing provided some insights into the
concentrations, chemical composition, photochemistry, and mutagenicity at the source of
emission. The PAH, NPAH and OPAH composition of the PM was similar throughout
2.5
the sampling periods, which included the period when a wide range of combustion
sources were controlled. In addition, it showed that PAHs were associated with both local
and regional emissions, while the NPAH and OPAH concentrations were only correlated
with the NO concentrations, indicating that the NPAH and OPAH were primarily
associated with local emissions. The characteristic NPAH ratios suggested a
predominance of photochemical formation of NPAHs through OH radical-initiated
reactions in the atmosphere.
Subsequently, the heterogeneous reactions of PAHs bound to Beijing ambient PM
with various oxidants, including NO /N O , OH radical and O , were studied using an
3 2 5 3
environmental reaction chamber under simulated trans-Pacific transport conditions. In
addition, PM collected from Riverside, CA was simultaneously exposed along with the
Beijing PM in order to allow us to compare the reactivity between two different sites. In
general, O was most effective in degrading PM-bound PAHs with more than five rings,
3
except for benzo[a]pyrene which was degraded by O and NO /N O equally well.
3 3 2 5
However, the NPAHs were most effectively formed during the NO /N O exposure. The
3 2 5
reactivity of the PM could be explained by the degree to which the PM had been
photochemically aged because the accumulation of degradation products on the surface
of PM appeared to inhibit further atmospheric degradation of parent PAHs. For the
NO /N O exposure, the increase in direct-acting mutagenicity was associated with the
3 2 5
formation of mutagenic NPAHs.
Additional laboratory experiments were carried out in order to identify
NPAH products of 5- to 6-ring PAHs through the heterogeneous reactions of surface-
bound PAHs with NO , NO /N O , O , and OH radicals. Five PAHs, benzo[a]pyrene-d ,
2 3 2 5 3 12
benzo[k]fluoranthene-d , benzo[g,h,i]perylene-d , dibenzo(a,i)pyrene-d , and
12 12 14
dibenzo[a,l]pyrene, were spiked onto quartz fiber filters and exposed in the chamber.
Some of the identified NPAH products have not yet been measured in the environment. In
parallel to the laboratory experiments, a theoretical study was conducted to assist in
predicting the formation of NPAH isomers based on the gas-phase OH radical-initiated
reaction. This study has shown that NO and NO /N O were effective oxidizing agents
2 3 2 5
in transforming PAHs deposited on filters to NPAHs, under these experimental
conditions. The lighter of the PAHs studied, including benzo[a]pyrene-d ,
12
benzo[k]fluoranthene-d and benzo[ghi]perylene-d , yielded more than one mono-nitro
12 12
isomer product, whereas dibenzo[a,l]pyrene and dibenzo[a,i]pyrene-d resulted in the
14
formation of only one mono-nitro isomer product. The direct-acting mutagenicity
increased the most after NO /N O exposure, particularly for benzo[k]fluoranthene-d in
3 2 5 12
which dinitro PAHs were observed.
©Copyright by Narumol Jariyasopit
May 17, 2013
All Rights Reserved
The Atmospheric Chemistry of Particulate-bound Polycyclic Aromatic Hydrocarbons:
Concentration, Prediction, Laboratory Studies, and Mutagenicity

by
Narumol Jariyasopit

A DISSERTATION
submitted to
Oregon State University

in partial fulfillment of
the requirements for the
degree of

Doctor of Philosophy

Presented May 17, 2013
Commencement June 2013
Doctor of Philosophy dissertation of Narumol Jariyasopit presented on May 17, 2013
APPROVED :

Major Professor, representing Chemistry

Chair of the Department of Chemistry

Dean of the Graduate School

I understand that my dissertation will become part of the permanent collection of Oregon
State University libraries. My signature below authorizes release of my dissertation to
any reader upon request.

Narumol Jariyasopit, Author
ACKNOWLEDGEMENTS
I wish to express my sincere thanks to my major advisor, Dr. Staci Simonich for
her advice, guidance, support, and patience over the years. I am grateful to her for this
precious opportunity to work on this project. I would also like to thank my committee
members, Dr. William Baird, Dr. Jennifer Field, Dr. Claudia Maier and Dr. Fredrick
Prahl, Dr. Paul Ha-Yeon Cheong for sharing your expertise and time on this research. I
wish to thank Dr. Janet Arey and Dr. Roger Atkinson, for their profound scientific
perspectives, advice, precious time, and resources. Also, I thank their last Ph.D. student,
Dr. Kathryn Zimmermann for her assistance and input in our collaborative projects. I
would like to thank Dr. Paul Ha-Yeon Cheong for teaching and advising on the
computational project. I thank Dr. Shu Tao and his graduate students at Peking
University for sample collection. I would also like to thank Dr. Joseph Nibler, my
undergraduate research advisor, for introducing me to scientific research and his
mentorship. I thank Dr. David Yu for teaching me the Salmonella mutagenicity assay and
providing the service.
I wish to express my thanks to my fellow laboratory members (Jill, Wentao, Leah
G., Carlos, Jing, Julie, Rita, Oleksii, Yuling, Leah C., Christopher, Scott, Melissa, Pun,
Kevin, Shelby, Anna), and friends in Corvallis for their encouragement and support,
especially when my right hand did not want to work. I am grateful to Jill, Nathan, and
Peter for editing my drafts. I appreciate all the help from the staff in the Chemistry and
Environmental and Molecular Toxicology departments at Oregon State University.
I am extremely thankful to my family and friends in Thailand for their infinite
support and sincerely tough criticisms. Lastly, I thank all the misfortune and failures that
have happened or will happen, I welcome them.
CONTRIBUTION OF AUTHORS
Dr. Staci L. Massey Simonich from Oregon State University provided advice and
support in all aspects of this dissertation.
For all the following studies, Dr. Tian-Wei Yu and Dr. Roderick H. Dashwood
provided advice and service in the Salmonella mutagenicity assay. Jill Schrlau assisted in
sample preparation and analysis and provided guidance in instrumental use and
maintenance. Dr. Shu Tao provided assistance in air sample collection.
Chapter 2. Dr. Shu Tao, Dr. Wentao Wang, Wei Zhang, Xuejun Wang from
Peking University provided assistance in air sample collection. Dr. Wentao Wang also
assisted in the particulate matter sample method development, sample preparation, and
sample analysis. Dr. Yuling Jia provided the high molecular weight polycyclic aromatic
hydrocarbon data.
Chapter 3. Melissa McIntosh synthesized the nitrated polycyclic aromatic
hydrocarbon standards. Dr. Rich Carter provided advice during the syntheses. Dr. Paul
Ha-Yeon Cheong provided advice and support in computational studies.
Chapter 3 and 4. Dr. Janet Arey, Dr. Roger Atkinson and Dr. Kathryn
Zimmermann from University of California, Riverside, provided Riverside particulate
matter samples, advice on experimental design, and technical support in environmental
chamber studies which were carried out at the Air Pollution Research Center, University
of California, Riverside. Additionally they also provided advice in data interpretation.