AIR TOXICS MONITORING NEWSLETTER
A PUBLICATION OF THE STAPPA/ALAPCO/USEPA AIR TOXICS MONITORING STEERING COMMITTEE
October 2001
National Air Toxics Monitoring Program
Two major projects are underway as part of the first
year of national air toxics monitoring:
1.	Pilot monitoring programs in four urban
areas and six small city/rural areas; and
2.	Analysis of existing (and the new pilot
project) air toxics monitoring data.
The U.S. Environmental Protection Agency (USEPA)
provided $3 million in FY2000 money for these two
projects. The status of these projects is summarized
below. In addition, USEPA provided another $3
million in FY2001 money for additional monitoring
projects by state and local agencies. These new
projects are also summarized below.
2001 Monitoring Pilot Project: The 2001 pilot
project, which is being funded out of the FY2000
money, is intended to generate information on the
spatial and temporal variability of ambient air toxics
concentrations. Ten state and local agencies are
participating in the project (see map below).
carbonyls, and metals. (Several small cities are not
monitoring for metals, however.) Preliminary data
collected has not shown any surprises. The data will
be included in the air toxics data analysis project
discussed below.
2002 Monitoring Projects: The 2002 projects,
which are being funded out of the FY2001 money,
are scheduled to begin monitoring in January 2002
(refer to the July newsletter for background on these
sites.) Some work has already begun, however, with
the Mobile, Alabama and Mississippi projects. All
data from these projects will be uploaded to AIRS
and will aid in network design decisions.
FY2002 Funding: The Air Toxics Monitoring Steering
Committee meets October 31 to formulate plans for
the $3 million grant allocation of FY2002 funds.
Grant guidance will be developed soon thereafter and
distributed to the Regions. The January newsletter
will include information on this outcome.
Air Toxics Data Analysis Project: The data analysis
project is intended to "mine" the existing monitoring
data to provide information about the spatial pattern,
temporal profile, and general characteristics of air
toxics compounds. The work is being performed by
Battelle Memorial Institute and Sonoma Technology,
Inc., under contract to LADCO. To supplement
Battelle's work, ICF Consulting is analyzing air toxics
modeling data to assess the spatial, seasonal, daily,
and diurnal variability of air toxics concentrations
from USEPA's recent ASPEN modeling performed as
part of their National Air Toxics Assessment and a
special ISCST modeling analysis by USEPA.
Draft reports were received from Battelle/STI and ICF
in September 2001. Based on the draft reports,
several key findings should be noted:
Map of Ten Cities in 2001 Monitoring Pilot Project
All 10 pilot cities are monitoring on their planned
schedules. Two of the "small" cities, Rio Rancho NM
and Keeney Knob, WV, had multiple equipment and
weather problems and thus their start dates were
delayed into August. Operations for the Detroit pilot
were transferred to the state of Michigan, due to the
closure of the Wayne County Air Monitoring Group.
All sites will provide at least 12 months of data.
Sampling is being conducted on primarily a 1-in-6
day frequency in the four urban areas, and a 1-in-12
day frequency in the six small city/rural areas. Each
area is sampling for at least 18 "core" VOCs,
• A nationally-consistent monitoring network is
needed with common sampling and analysis
procedures, a common set of compounds,
and common data reporting. This network
must reflect the following monitoring
objectives:
o characterize ambient
concentrations;
o support modeling; and
o assess trends.
To address all these needs, a nested
approach with a national "core" set of
monitors is recommended. The network of
core monitors may not be sufficient to

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address local concerns, in which case a
strategic planning decision must be made
as to whether monitoring for local concerns
should be a component of the national
program/network, or an activity that should
remain at the discretion and funding of
state and local agencies, as it has been in
the past.
•	In the absence of local major point sources,
very few monitoring stations (possibly only
one) may be needed to meet the objective of
characterizing annual average
concentrations across an urban area.
•	Monitor siting should consider all available
local information, especially any reliable
modeling data, current emissions
inventories, and representative wind data.
ASPEN modeling, in particular, can be used
to help establish neighborhood- or
urban/regional-scale monitors.
•	Mobile monitoring stations provide a cost-
effective, flexible approach to measuring
ambient concentrations over a wider
geographic area (as compared to fixed
monitoring stations).
•	To provide a reliable annual average
concentration, sampling should be
performed year-round for a 24-hour period
(midnight-to-midnight) at least every sixth
day (or every third day for higher
concentration or source-oriented sites).
•	A basic suite of air toxics compounds (e.g.,
the 18 compounds of interest in the pilot city
monitoring) can be measured adequately
with current monitoring methods. To
measure other compounds of interest, it will
be necessary to develop more cost-
effective, practical methods.
This analysis of existing air toxics data represents an
important first step in developing network
recommendations. Additional steps include
completion of the full year of pilot city monitoring in all
10 areas (which should be done by summer 2002), a
thorough analysis of these data (which can be done
by late 2002), and consideration of any additional
material, such as updated emissions inventories and
modeling, and information on current monitoring
methods. Of course, implementation of a national (as
well as a regional and local) monitoring network is
expected to require substantial resources. It is
unclear exactly how much this would cost or how it
will be paid for.
Portland Air Toxics Monitoring Program
As planning for the national air toxics monitoring
network proceeds, several state/local agencies will
continue to operate their own air toxics monitoring
programs. The existing monitoring network operated
by the State of Oregon in Portland is discussed here.
(Other state/local programs will be discussed in
future editions of the newsletter.)
The State of Oregon collected data from July 1999
through July 2000 at five sites relying on one-time-
only grant funds. Volatile organics, semi-volatile
organics, carbonyls, and total suspended particulate
trace metals were measured on a 1 -in-6 day
sampling schedule. All of the sites were deployed
within the Portland urban area (shown on the map
below) in residential and/or commercial areas where
significant population exposures would occur.
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Map of Monitoring Sites in Portland, Oregon
Characterizing air quality with respect to air toxics, in
order to provide (measured) data to the citizens of
Portland, was the primary objective of the project.
Finding a single site that might be considered
representative of the urban area, and could be used
for trend analysis, was also an important objective of
the study.
After initial examination of the data, it was evident
that no one site stood out as being universally
representative. Relatively simple correlation
analyses done by both EPA Region X and Oregon
DEQ staff pointed to some sites being better
predictors for some key organics, but showed little
correlation between sites for the metals. In general,
the N/NE and SE sites were more typical of
residential exposure to mobile and area sources,
while pollutant levels were generally higher at the NW
and N/NE sites. The NW site was closest to a large
concentration of industrial sources located near the
confluence of the Willamette and Columbia Rivers.
Overall, the N/NE site was chosen for the Portland
trend site, as it seemed to best meet the objective of

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a residential neighborhood-scale site with relatively
high levels of toxic air pollution resulting from a
variety of sources. The monitoring results were
presented at two community meetings, and the
process used to select the trend site was described.
An opportunity to provide additional information or
arguments for either supporting that selection, or
recommending an alternative, resulted in several
comments, but no change was made in the initial
selection of the N/NE site.
These Portland project data were used by Battelle as
one of the case studies. The Battelle analysis also
suggests that local emissions sources contribute to
local spatial variability, but in the absence of these
sources, the spatial gradients are so flat, especially
on an annual basis, that little information is to be
gained from adding more sites. Their analysis also
indicates that what is a source-oriented site for some
compounds may not be so for others, suggesting a
potential need to monitor different compounds (or
classes of compounds) at different sites in some
cases.
Because Oregon has no stable source of funding for
an air toxics monitoring network, it will have to
continue to rely on project-specific grants to keep
operating in the foreseeable future and needs to find
economic al ways to do that. Oregon DEQ found
another one-time grant to support the Portland site in
2001, and will use funding from the national FY01
grant to continue monitoring in 2002.
(Thanks to Gregg Lande, Oregon DEQ for this
article.)
October Air Toxics Workshop
On October 29 - 30, 20001, a workshop will be held
in Rosemont, IL (near Chicago's O'Hare Airport) to
review the results (to date) from the 2001 monitoring
pilot projects and the data analysis work. The
workshop will begin at 1:00 pm CST on Monday,
October 29. The first half-day of the workshop will
include reports from each of the 10 pilot city areas.
The second full day will include reports from Battelle
and ICF on their data analyses. The workshop will
end at 5:00 pm CST on Tuesday, October 30. To
register for the workshop, please contact Winnie
Leva, LADCO, leva@ladco.ora. 847-296-2181.
For information on the monitoring pilot projects,
please contact Sharon Nizich, USEPA, OAQPS,
nizich.sharon@epamail.epa.aov. 919-541-2825.
For further information on the data analysis projects,
please contact Michael Koerber, LADCO,
koerber@ladco.ora. 847-296-2181. This newsletter
will be issued on a regular (quarterly) basis to provide
status reports on air toxics monitoring activities.

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