United States
Environmental Protection
Agency
Environmental Monitoring Syste
Laboratory
Research Triangle Park NC 2771
Research and Development
EPA-600/S4-85-045 Aug. 1985
&ERA Project Summary
Review of Sampling and
Analysis Methodology for
Polynuclear Aromatic
Compounds in Air from
Mobile Sources
C. C. Chuang and B. A. Petersen
The objective of this program was to
review and recommend test compounds
and sampling and analysis methods for
a future EPA study of polynuclear
aromatic hydrocarbons (PAH) in micro-
environments.
A literature survey was performed by
a computer search of nine data bases:
Chemical Abstracts (1967-1983), En-
viroline (1971-1983), Pollution Ab-
stracts (1970-1983), APTIC (1966-
1978), NTIS (1964-1983), Engineering
Index (1970-1983), BIOSIS (1970-
1983), Excerpta Medica (1970-1983),
and Medline (1970-1983). Additional
materials representing state-of-the-art
practice were also reviewed.
Review of PAH profiles in ambient air
indicated that concentrations of PAH
were generally higher in winter than
summer and varied with climate and
between sampling sites within an urban
area. Levels of several PAH were found
to be proportional to traffic density.
Studies of the biological activity of
ambient air samples showed that some
PAH and their nitrated derivatives are
extremely carcinogenic and mutagenic.
The following compounds were deter-
mined to be the most prevalent and
mutagenic or carcinogenic in ambient
air and were recommended for the
future EPA study: phenanthrene, py-
rene, cyclopenta(c,d)pyrene, benzo(a)-
pyrene, dibenz(a,h)anthracene, 1 -nitro-
pyrene, fluoranthene, benz(a)anthracene,
benzo(e)pyrene, benzo(g,h.i)perylene,
coronene, and 3-nitrofluoranthane.
In the review of PAH sampling me-
thods, collection of both gaeous and
particulate-bound PAH was determined
to be necessary to accurately character-
ize health effects of PAH in ambient air.
Most studies have used filters to sample
particulate-bound PAH and adsorbents
to collect vapor phase PAH. The major
sampling problems encountered in
these studies were PAH losses due to
volatilization and reactivity. A modified
high volume (Hi-Vol) sampler which can
remove large particulates (>10 yum) and
collect both particulate and vapor phase
PAH was recommended for the EPA
study.
Both screening and analytical meth-
ods for PAH determination were re-
viewed. Luminescence techniques, thin
layer chromatography, ultraviolet (UV)
spectroscopy, and a fluorescence spot
test have been successfully applied in
previous PAH screening studies and
were recommended for the EPA study.
For PAH analysis, combined gas
chromatography/mass spectrometry
(GC/MS) with either electron impact or
negative ion chemical ionization was
found to provide higher sensitivity and
specificity than other techniques re-
viewed and was recommended for the
future study.
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This Project Summary was developed
by EPA's Environmental Monitoring
Systems Laboratory, Research Triangle
Park, NC, to announce key findings of
the research project that is fully docu-
mented in a separate report of the same
title ~(see Project Report ordering in-
formation at back).
Introduction
The Methods Development Branch is
developing sampling and analytical
methodology for an experimental study of
human exposure to polynuclear aromatic
hydrocarbons (PAHs) and PAH derivatives
in ambient air within microenvironments,
emphasizing those which originate from
mobile sources. The form and concentra-
tion in which these PAH materials appear
in microenvironments are matters of
increasing interest and importance be-
cause of the increasing use of diesel
powered vehicles. Of particular concern
is the presence of nitrated PAHs in diesel
exhaust. PAHs, especially pyrene, have
been reported to react readily with nitro-
gen oxides to form nitrated derivatives,
which are powerful direct acting muta-
gens. Both the PAHs and nitrogen oxides
are present in combustion emissions;
thus the formation of nitroaromatics in
these emissions or in subsequent atmos-
pheric reactions is possible. In recent
studies conducted by Battelle Columbus
Laboratories, nitrated PAHs have been
identified in urban air particulate samples.
Reliable sampling and analytical tech-
niques need to be established before
potential effects of PAHs and PAH deriva-
tives on the environment can be assessed.
The specific objectives of this project
were to survey and review the current
knowledge of PAHs found in ambient air
and to use the results of the review to
develop a design and analytical method-
ology for an experimental study of human
exposure to PAH found in ambient air
within microenvironments.
The first phase of this project is a
review of the available literature to de-
termine:
• Sampling and analysis methodology
for PAHs in ambient air.
• Specific PAH compounds and sub-
classes of the PAHs that are potentially
most important because of their long-
term health risk.
• PAH profiles from specific mobile
sources that can be used to relate the
PAH concentrations m air to those
sources.
Procedure
A literature survey was performed by a
computer search of nine data bases:
Data Base
Chemical Abstracts
Enviroline
Pollution Abstracts
APTIC
NTIS
Engineering Index
BIOSIS
Excerpta Medica
Medline
Years Searched
1967-1983
1971-1983
1970-1983
1966-1978
1964-1983
1970-1983
1970-1983
1970-1983
1970-1983
Because the citations obtained from
Chemical Abstracts listed only the authors
and topics, a manual search of the
abstracts of those topics of interest was
performed. To collect information that
might have been missed in the computer
search, a manual review was also con-
ducted of other sources considered to
represent current state-of-the-art prac-
tice, such as handbooks, manuals, and
research reports published by the USEPA
and recognized professional organizations.
Over 1000 citations were obtained as a
result of both computer and manual
searching. Abstracts and citations con-
sidered most relevant to the subject area
were reviewed and divided into two
subsets, sampling methods and analysis
methods, for further evaluation. Photo-
copies of some important articles were
obtainedtoallowfora morecritical review
than abstracts alone provided
Results
The results of this review are presented
in these three sections of the report:
• PAH profiles and biological activity
from ambient air samples,
• Sampling methodology for the collec-
tion of PAHs, and
• Chemical analysis methodology.
The relative importance of PAHs that
are found in ambient air and that originate
from mobile sources, in terms of their
long-term health risk, is addressed in the
first section. Sampling, analytical and
screening methodologies for the meas-
urement of PAHs and PAH derivatives
that may be suitable for a USEPA pro-
posed experimental study are identified
and evaluated in the other two sections
These methodologies will be usedtoguide
the development of an experimental pla
for a human exposure study.
Conclusions and
Recommendations
Several important characteristics c
PAH profiles in ambient air and the!
biological activity have been identified ii
this review. PAH concentrations in ambi
ent air vary widely and in general an
higher in winter than in summer. Thi
concentrations of PAH compounds alsi
vary between sampling sites within ai
urban area and vary with climate. How
ever, levels of several PAHs such a
cyclopenta(c,d)pyrene, benzo(g,h,i)pery
lene, and coronene are directly proper
tional to traffic density. These compound
can be used, therefore, as indicators ti
identify the origin of mobile source con
lamination within microenvironments
Based on these characteristics, sucl
compounds should be considered fo
monitoring in the EPA experimental study
Several carcinogenic and mutagenn
PAHs and PAH derivatives found n
ambient air should also be investigated ii
the EPA study. Benzo(a)pyrene, benzo
fluoranthenes, cyclopenta(c,d)pyrene am
dibenz(a,h)anthracene are known carcmo
gens and therefore should be considerei
important compounds to be monitored n
the future study.
Nitropyrenes and mtrofluoranthenei
are potent direct-acting mutagens an<
have been identified in both ambient ai
and automobile exhaust. Dmitropyreni
andhydroxynitropyrenearetwo material;
with the highest mutagenicity known t<
date and have been found in mobil<
source emissions. While these two com
pounds have not yet been found u
ambient air, they will probably be found n
microenvironments polluted by thesi
sources
Based on the available information, tht
following PAH compounds are potentia
candidates to be monitored in the EPX
experimental study, phenanthrene, flu
oranthene, pyrene, benz(a)anthracene
cyclopenta(c,d)pyrene, benzo(e)pyrene
benzo(a)pyrene, benzo(g,h,i)perylene, di
benz(a,h)anthracene, coronene, 1-nitro
pyrene, 3-nitrofluoranthene, benzofluo
ranthenes, and mdeno(1,2,3-c,d)pyrene
Monitoring for the above species wouli
provide a general characterization of PAH
concentration in ambient air The meas
urement of these compounds can be usei
to assess the PAH profile in a wide variet'
of microenvironments, including thosi
containing emissions from mobile an|
stationary sources. Furthermore, thi
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same compounds can be used to assess
the PAH concentration within residential
sites. For this application, it would be
highly desirable to correct for PAH con-
tributed by tobacco smoke. This correction
can be made, if a correlation exists
between PAH compounds and several
tobacco smoke products such as quinoline
and isoquinoline. If such a correlation
exists, then an adjustment of the PAH
concentration due to tobacco smoke can
be made. Thus, by including tobacco
smoke marker compounds in the list of
compounds to be monitored, residences
and work places can be included as
microenvironments.
Sampling methods used in the EPA
future study must collect representative
samples of potentially harmful PAHs in
ambient air and must also minimize
sampling losses frequently encountered
with PAHs. PAHs exist in vapor and
particulate phases in the atmosphere,
and most particle-bound PAHs are found
in the submicron range. These small
particles also produce a major percentage
of the mutagenic activity of airborne
particulate matter. Both the vapor and
respirable particle-bound PAHs should be
considered for collection, and an appro-
priate sampling and analysis system
should be designed for the experimental
study.
PAH losses in sampling are mainly due
to volatilization and reactivity with N02,
03, and UV radiation. Volatilization of
PAHs cannot be avoided, but can be
minimized by the use of back-up traps in
the sampling system for collection of
vapor phase material. Some reactive
PAHs are believed to undergo atmos-
pheric reaction, such as nitration, to
convert PAHs to nitro PAHs. Erroneous
results will occur if these reactions
continue during the sampling and analy-
sis procedure. In general, reactivity
mechanisms of PAHs in the atmosphere
are not well defined, and a simple solution
to eliminate reactivity losses in sampling
has not yet been demonstrated. A device
to remove Oa and NOz prior to particle
sampling should be considered to mini-
mize this degradation.
The recommended sampling device for
the EPA experimental study is a modified
Hi-Vol sampler. With a properly designed
sampler inlet, a modified sampler can
remove larger particles (>10 /jm) before
passage of the air sample through the
collection system. The collection system
should consist of a filter medium to collect
particulate matter and a solid sorbent
cartridge to trap vapors. Proper sampling
procedures need to be designed and
validated to avoid volatilization losses and
reduce reactivity problems.
The procedures to be developed should
consider the following parameters:
Sampler configuration
Sampling time
Sampling temperature
Sampling flow rate
Filter face velocity
Frequency of samples
Quantity of sample necessary for
measurement
Once ranges have been established, the
operation of samplers can be optimized
for the specific site selected.
Rapid screening methods for PAHs
identified in this review include a sensi-
tized spot test, UV spectroscopy, TLC with
fluorescence and/or UV detection, and
luminescence techniques.
Several analytical techniques such as
HPLC with UV and/or fluorescence de-
tection, GC/FID, and GC/MS have been
used successfully to measure PAHs in
ambient air and can be considered for the
EPA experimental study. The HPLC tech-
nique is very sensitive and less expensive
than the GC/MS technique. It may be
possible to determine PAHs using HPLC
methods without sample cleanup. If so, it
may be possible to perform HPLC analyses
in the field. No reference has been found
describing the use of synchronous fluo-
rescence (SF) detection with HPLC for the
determination of PAHs in air. This tech-
nique offers several advantages in terms
of improved sensitivity and specificity.
Therefore, development and evaluation
of SF detection with HPLC is also sug-
gested for the future study. It should be
noted that single column GC or HPLC
analyses employing single detectors do
not give unambiguous results, and con-
firmation of these analytical results with
specific techniques such as GC/MS is
necessary.
Capillary column GC/FID has been
demonstrated to be useful as a routine
analytical tool for PAH determinations. A
sample cleanup procedure is required to
remove the interference from aliphatic
hydrocarbons, few analytical methods
for detection of nitro PAHs are reported in
the literature. The negative ion Cl GC/MS
technique is very sensitive, but requires
the use of expensive and sophisticated
equipment. Therefore, less expensive
methods such as GC and/or HPLC tech-
niques should be developed and evaluated
for the determination of nitro compounds
in the future study. In the future EPA
experimental study—for the most impor-
tant sample types, which demonstrate
unusually high mutagenicity and/or car-
cinogenicity—more sophisticated analyt-
ical techniques (such as El GC/MS and
NCI GC/MS) will be required to provide,a
more complete chemical characterization.
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C. C. Chuang is withBattelle Columbus Laboratories, Columbus, OH 43201, and
B. A. Petersen is with SCIEX, Inc., Worthing/ton, OH 43085.
Nancy K. Wilson is the EPA Project Officer (see below).
The complete report, entitled "Review of Sampling and Analysis Methodology
for Polynuclear Aromatic Compounds in Air from Mobile Sources," (Order No.
PB 85-227 759/AS; Cost: $10.00, subject to change) will be available only
from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Environmental Monitoring Systems Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
United States
Environmental Protect1 ->n
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
EPA/600/S4-85/045
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