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Appendix B
Review of Air Monitoring Data from Joint Base Balad
This appendix provides supplemental information on the air monitoring data collected at Joint Base Balad
(JBB) and discussed in Chapter 4. The main focus of the appendix is on the strengths and limitations in the sample
collection and analysis. A discussion of the sampling issues for specific chemical classes detected at JBB—poly -
cyclic aromatic hydrocarbons (PAHs), particulate matter (PM), metals, volatile organic compounds (VOCs), and
polychlorinated dibenzo-para-dioxins/furans (PCDDs/Fs)—is also given.
STRENGTHS AND LIMITATIONS OF THE AMBIENT DATA
In each monitoring campaign at JBB, ambient air concentrations of PM 10, metals, speciated VOCs, PAHs, and
PCDDs/Fs were determined using standard EPA methodologies. In the 2009 campaign, PM 2.5 was also measured.
The following standard EPA sampling methods for toxic organics (TO) were used (EPA 1990):
• T
O-9 sampling for PCDDs/Fs;
• T
O-13A sampling for PAHs;
• T
O-14 sampling for VOCs in 2007;
• T
O-15 sampling for VOCs in 2009; and
• M
iniVol sampling for particulate matter with aerodynamic diameter less than 10 mm (PM10) in 2007 and
also less than 2.5 mm (PM2.5) in 2009; the PM10 samples were also analyzed for individual metals by
inductively coupled plasma mass spectrometry (ICPMS; Method 200.8).
For each method, samples are obtained by passing ambient air at a constant rate through a sampling apparatus
for a fixed time, either to collect the materials (generally air pollutants) on a filter and/or sorbent (TO-9, TO-13A,
Mini-Vol methods) or to collect a sample of the air itself (TO-14, TO-15 methods). The TO-9, TO-13A, TO-14,
and TO-15 methods are designed to capture both vapor-phase and particulate-phase material. Photographs of the
monitoring equipment are given in the CHPPM report and each instrument appears to have collected samples at
about 4 feet above the ground (Taylor et al. 2008). The collected material is subsequently analyzed for specific
chemicals. The measurements at JBB are the average concentration of the measured material in the air over the
(approximately) 24-hour sampling period. Any spikes in concentration that may occur because of variations in
133
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134 HEALTH CONSEQUENCES OF EXPOSURE TO BURN PITS
source conditions or meteorology during the measurement period are incorporated into the 24-hour average, and
are not discernible in the data except insofar as they affect the average.
The measurements also include all amounts of the material in ambient air regardless of the source. They
do not directly measure emissions from the burn pit or from any other particular source. There are likely to be
multiple sources of all the measured chemicals either on or in the vicinity of JBB, and the measurements include
background concentrations due to those other sources as well as concentrations from the burn pit. The background
concentrations from those other sources vary between sample times as a result of variations in time, number of
sources, or location of those sources, as well as variations in meteorological conditions.
Several details of the sampling design and methodology affect the committee’s ability to analyze the sampling
data. Such details have different effects on different analyses, so the following comments should not be interpreted
as criticisms of the sampling design or methodology, since the samples were collected for a different purpose.
• amples were not collected simultaneously at all locations for each sampling event. An effort was made
S
to sample all the individual pollutant types (VOCs, semivolatiles, PM, PCDDs/Fs) on the same day, and
there is substantial overlap in the sampling start times and the length of time for each sample, but they
vary by as much as several hours both within and between pollutant types. This limits the comparability
of samples, since the weather conditions and sources of pollutants are likely to be different in character,
number, and strength at different times of day. Consequently, comparisons between the different sites are
made more difficult, and identification of distinct sources from the sample data is compromised to some
extent.
• amples were not collected on any planned schedule. Instead a “convenience sampling” approach was used
S
in which samples were collected when logistically possible. As a result, averages of the sample results may
be unrepresentative of long-term average exposures because of unrecognized patterns in exposure (e.g.,
daily, weekly, monthly, or seasonal variations) not compensated by averaging the measurements.
• he PM methodology used is not suited for collecting samples with high concentrations of PM, such as
T
occur during dust storms, or even on many non-dust-storm days at JBB (NRC 2010). As a result, some
of the filter samples probably suffer from sampling artifacts (underestimates or overestimates of PM con -
centration). The 2009 samples, where PM10 and PM2.5 samples were collected simultaneously at the same
locations, show evidence of such problems. The ratio of PM2.5 to PM10 was between 0.25 to 0.6 for most
samples, but a few showed substantially higher or lower ratios. In particular, for some samples the ratio
•
exceeded unity (the ratio should always be less than unity except for measurement errors, since PM 2.5 is a
component of PM10). Similar problems are likely to have occurred with PM10 sampling in 2007, and may
have been masked in some 2009 samples by occurring simultaneously in both PM 10 and PM2.5 samples.
Further evidence of these problems is provided by some large discrepancies in measurements of the same
parameter (PM2.5 or PM10) at the different sampling sites on the same day.
• onitoring at different areas of the site would have been helpful. A site closer to the burn pit might have
M
been more strongly and clearly affected by this source, allowing better characterization of the burn pit
emissions. Sites in all the housing areas would allow better evaluation of exposures to all personnel on
base rather than just those initially thought to be most highly exposed. Use of paired sites relatively close
together, rather than single sites, may have compromised the analytic methods the committee attempted to
use, since the paired sites were sufficiently far apart to be affected differently by local sources. Moreover,
since these closely spaced sites were not sampled simultaneously, they do not provide any useful informa -
tion on the variation of exposures within the housing area.
• he TO-14/TO-15 methodology (in which a sample of air is collected in an initially evacuated stainless
T
steel flask) is not well suited to measure polar or reactive organics such as acrolein and 1,3-butadiene.
Such materials may react on the walls of the stainless steel flask or in the gas phase during storage and
transport of the sample. For example, 1,3-butadiene will decompose inside the canister during storage,
mostly by reactions with nitrogen oxides. For risk assessments this is an important issue, because acrolein
and butadiene are often the major risk contributors in screening risk assessments.
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135
APPENDIX B
TABLE B-1 Average PAH Concentrations (ng/m3) at JBB
Guard Tower/
Transportation Field H-6 Housing/CASF Mortar Pit
Spring Fall Spring Fall Spring Fall
Analyte 2007 2007 2009 2007 2007 2009 2007 2007 2009
Acenaphthene 3.3 5.6 1.8 5.6 3.0 2.2 3.2 2.4 2.0
Acenaphthylene 5.7 24.4 3.5 12.1 14.2 8.3 4.9 8.7 2.7
Anthracene 2.8 6.2 1.3 3.4 2.8 1.0 2.0 2.0 0.5
Benz[a]anthracene 1.6 2.8 0.9 1.7 1.4 0.7 1.6 0.8 0.6
Benzo[a]pyrene 1.0 2.7 1.0 0.9 1.7 1.0 0.9 1.7 1.0
Benzo[b]fluoranthene 2.8 5.5 1.9 2.2 3.0 1.9 2.8 2.2 1.8
Benzo[e]pyrene 1.6 3.0 1.1 1.2 1.5 1.1 1.5 1.2 1.0
Benzo[g,h,i]perylene 1.5 3.3 1.3 1.2 2.7 1.7 1.4 1.7 1.4
Benzo[k]fluoranthene 0.6 1.2 0.5 0.5 0.7 0.4 0.6 0.5 0.5
Chrysene 2.5 3.7 2.5 2.4 2.3 1.6 2.1 1.3 1.4
Dibenz[a,h]anthracene 0.3 0.7 0.3 0.2 0.3 0.1 0.3 0.3 0.1
Fluoranthene 7.8 10.9 4.8 7.9 6.6 4.5 5.5 4.3 4.1
Fluorene 12.3 24.1 9.3 16.1 11.7 8.0 8.7 8.1 6.6
Indeno[1,2,3-cd]pyrene 1.4 3.2 1.1 1.1 2.0 1.2 1.3 1.7 1.3
Naphthalene 200.0 536.9 205.3 242.9 348.4 283.8 133.7 335.5 201.9
Phenanthrene 29.4 45.1 19.5 34.6 23.2 17.4 20.5 15.8 15.1
Pyrene 6.4 9.1 3.4 6.9 6.1 3.5 4.6 3.6 2.9
Number of samples 9 10 19 11 7 17 10 6 18
• he sampling locations were chosen to evaluate concentrations downwind of the burn pit (Taylor et al.
T
2008). The committee was initially informed that no military personnel serviced the burn pit at JBB, but
subsequent information indicated that military personnel worked at or very near the pit. The concentration
of contaminants in or near the pit cannot be inferred from any of the samples obtained, so there could be
a subpopulation of military personnel who were highly exposed but whose exposure cannot be estimated
from available data.
Polycyclic Aromatic Hydrocarbons
Measurements of PAHs were obtained at five sampling sites at JBB, but for 2007 these were reported as
three locations—the guard tower/transportation field (20 samples),1 H-6 housing/CASF (18 samples) and mortar
pit (16 samples) (Table B-1). In 2007, samples were collected on each of 22 days, but on only 12 days were all
three locations sampled. The 2009 measurements were again taken at the five sampling sites, and were reported
separately for the five sites; but they are treated here as the three sampling locations as was done for the 2007
samples—the guard tower/transportation field (19 samples), H-6 housing/CASF (17 samples) and mortar pit (18
samples). Some samples were collected on each of 20 days, but only on 15 days were all three locations sampled.
The nominally 24-h samples were not obtained simultaneously at the three locations on the common sampling
days, but began within 2.5 hours in 2007, and within 1.6 hours in 2009; the sample times varied from 17.4 hours
to 25.4 hours in 2007, and 21.1 hours to 25.2 hours in 2009. In both 2007 and 2009 each sample was analyzed for
17 PAH analytes, with all of the analytes detected in most samples. 2
1 Twenty-one samples results are reported in the data provided to the committee and used by Taylor et al. (2008), but one clearly corresponds
to an unexposed sample and is omitted from further consideration here.
2 The omitted sample was nondetect for every PAH except naphthalene, which was measured at a level 50 times lower than the next lowest
sample. The committee considers this to be an unexposed sample.
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136 HEALTH CONSEQUENCES OF EXPOSURE TO BURN PITS
Particulate Matter and Metals
The 2007 PM measurements included 28 to 32 samples at each of the three sampling locations (total 90
samples) on a total of 32 sampling days. PM10 samples were obtained by specifically collecting particles with
aerodynamic diameters less than 10 mm on filters. The measurement consists of a careful weighing of the filter
before and after the collection period; then knowledge of the amount of air directed through the filter allows
computation of the average concentration of PM10 in the air. The PM on the filter was then analyzed for the fol-
lowing metals: antimony, arsenic, beryllium, cadmium, chromium, lead, manganese, nickel, vanadium, and zinc.
For the CHPPM samples at JBB in 2007, the measurements of individual metals were not useful, because the
detection limit of the method used was too high to detect the metals of interest in the PM 10 material in the great
majority of samples. Only 6 detections, all of lead, were made in the 90 samples; these detections were all made
on 2 consecutive days in November 2007 and all were less than 0.7 mg/m3. The committee therefore disregarded
the metals measurements as not providing useful information.
In 2009, 50 measurements were available for 19 days of near-simultaneous PM 10 or PM2.5 samples, together
with another 8 samples of PM10 or PM2.5 individually, although four of the PM10 measurements were clearly
affected by measurement artifacts and were ignored by the committee. The collected PM 10 material was analyzed
for metals, and again the detection limits were sufficiently high that most of the samples had nondetectable levels
of the metals of interest. There were, however, many more detections than in 2007—25 of 108 samples had at least
one metal detected—despite detection limits that were very similar; the concentrations of the metals varied, with
individual concentrations up to 5 mg/m3. The third highest PM10 measurement was discounted because it suffered
from measurement artifact (by comparison with the simultaneous PM2.5 measurement), and the consistency of the
two available PM2.5 measurements on the same day strongly suggests that the second highest PM 10 measurement
also suffered from the same problem.3
Volatile Organic Compounds
VOCs were detected in 66 samples in 2007 and in 55 samples in 2009. The likely sources were considered to
be combustion (including petroleum fuel combustion), fuel additives, solvents, and refrigerants. The 2007 measure-
ments of VOCs included 66 samples on 26 days, using TO-14 methodology for sample collection. Each sample
was analyzed for 78 VOCs. Fifty-five of these analytes were detected in six or fewer samples. The frequency of
detection and likely major sources or uses for the other 28 analytes are shown in Table B-2.
The 2009 measurements included 57 samples on 20 days. There was a change to TO-15 methodology, so each
sample was analyzed for up to 62 VOCs, including some not measured in 2007, and some of those measured in
2007 were omitted from the analyte list in 2009. Forty of the VOCs were detected in six or fewer samples. The
frequency of detection and likely major sources or use for the other 22 analytes are shown also in Table B-2.
The differences between these lists largely arise from the different analytes measured or different detection
limits in 2007 and 2009. Octane, isooctane, chlorodifluoromethane and pentane were analyzed in 2007 but not in
2009, while the xylenes were analyzed in different combinations. Isopropyl alcohol and cyclohexane were analyzed
in 2009 but not in 2007. The detection limits for acrolein, 2-butanone, methylene chloride, and 1,4-dichlorobenzene
were lower in 2009 than in 2007, although as discussed earlier the method used for acrolein was inadequate. The
detection limit for MtBE was higher in 2009 than in 2007, and the average detected concentration in 2007 was
half the 2009 detection limit. However, 4-ethyltoluene was detected less frequently and at lower concentrations in
2009 (even with a lower detection limit).
Table B-3 presents average concentrations of the twelve most frequently detected VOCs by location and
sampling campaign, with nondetects assumed to contribute one-half the detection limit (for these VOCs, setting
nondetects to zero alters the mean estimate by a factor of 1 to 2.4). Like PM 10, VOC concentrations were similar
3 This assumes negative artifacts (underestimation of concentrations). Since positive artifacts are also quite likely at high PM concentrations
with the methodology used for measurement at JBB (NRC 2010), this evaluation of artifact could be entirely backward. In that case the majority
of high concentration measurements could be artifacts.
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137
APPENDIX B
TABLE B-2 Number of Detects and Likely Source for Analytes Detected More than Occasionally in 2007 and
2009
Number of detectsa
2007 2009
Analyte Likely major source or use
Acetone 66 55 Solvent, combustion
Benzene 66 56 Combustion
Chloromethane 66 54 Natural sources (ATSDR 1998, 1999)
Toluene 63 56 Petroleum-based fuel combustion
Hexane 65 53 Petroleum-based fuel combustion
Pentane 65 NA Petroleum-based fuel combustion
Dichlorodifluoromethane 64 55 Refrigerant
Propylene 32 55 Petroleum-based fuel combustion
2-Butanone (MEK) 20 53 Solvent, combustion
Methylene chloride 27 52 Solvent
o-Xylene 51 52 Combustion
n-Heptane 60 36 Petroleum-based fuel combustion
Ethylbenzene 49 49 Combustion
m,p-Xylene 55 NA Combustion
Xylenes, total NA 45 Combustion
1,2,4-Trimethylbenzene 51 41 Combustion
Octane 46 NA Petroleum-based fuel combustion
Trichlorofluoromethane 42 37 Refrigerant
Chlorodifluoromethane 41 NA Refrigerant
Acrolein 4 34 Combustion
4-Ethyltoluene 38 12/30 Combustion
Isopropyl alcohol NA 27 Solvent, disinfectant
Methyl tert-butyl ether (MtBE) 29 0 Anti-knock fuel additive
1,3,5-Trimethylbenzene 24 11 Combustion
Isooctane 17 NA Anti-knock fuel additive
Styrene 17 14 Combustion
1,4-Dichlorobenzene 4 9 Mothballs, pesticide
Cyclohexane NA 8 Petroleum-based fuel combustion
NOTE: NA = not analyzed.
aTotal possible detects 66 in 2007 and 57 in 2009 except 4-ethyltoluene.
for many analytes at all the measurement locations at JBB, and there did not appear to be any consistent gradients
in concentration, although differing gradients exist for some analytes at some times.
Polychlorinated Dibenzo-Para-Dioxins/Furans
During 2007, 18, 21, and 21 PCDD/F nominal 24-hour samples were collected at the guard tower/transpor-
tation field, H-6 housing/CASF, and mortar pit locations, respectively, on 20 sampling days (TO-9 method; 60
samples total). Two of the samples for the H-6 housing/CASF and mortar pit locations were obtained on the same
day (about 2 hours and 20 minutes apart in starting time, respectively), and on 2 of the 20 sampling days the
guard tower/transportation field was not sampled. All samples were analyzed for the seventeen 2,3,7,8-chlorinated
PCDD/F congeners, with all congeners detectable in 41 or more of the 60 samples except 1,2,3,7,8,9-hexaCDF
(detected in 14/60 samples).
The 2009 sampling data for PCDD/PCDFs included 19, 17, and 18 PCDD/F nominal 24-hour samples at the
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138 HEALTH CONSEQUENCES OF EXPOSURE TO BURN PITS
TABLE B-3 Average Concentration (mg/m3) of the 12 Most Frequently Detected VOCs at JBB
Guard Tower/
Transportation Field H-6 Housing/CASF Mortar Pit
Spring Fall 2009 Spring Fall 2009 Spring Fall 2009
Analyte 2007 2007 2007 2007 2007 2007
Benzene 6.8 9.1 4.9 4.8 5.0 3.8 3.3 8.3 2.7
Acetone 37.9 10.8 29.6 25.7 9.4 42.7 13.8 6.8 29.7
Chloromethane 2.0 1.6 1.9 1.9 1.1 1.7 1.5 1.2 1.8
Dichlorodifluoromethane 4.3 2.5 2.5 3.0 2.6 2.6 2.7 2.3 2.5
Toluene 11.8 23.0 10.7 8.6 30.2 13.1 5.0 55.2 9.8
Hexane 5.1 4.5 5.3 2.9 5.4 31.6 2.1 16.2 7.2
Xylenes 7.2 22.4 7.7 9.6 18.3 8.9 4.6 52.6 6.4
Ethylbenzene 4.0 4.8 2.9 3.2 5.3 2.7 2.4 9.6 1.7
n-Heptane 3.6 2.9 2.1 4.1 3.5 2.8 1.8 6.5 1.9
1,2,4-Trimethylbenzene 2.6 18.0 2.0 3.7 9.3 2.9 2.2 11.9 1.8
Propylene 2.7 3.8 2.2 1.6 2.8 2.0 1.2 4.8 1.3
Methylene chloride 10.1 2.7 17.3 2.3 2.1 17.9 2.5 3.0 8.3
Number of samples 15 8 19 12 9 18 15 7 19
guard tower/transportation field, H-6 housing/CASF, and mortar pit locations, respectively, on 19 sampling days,
with 3 different days missing a sample at one location (TO-9 method; 54 samples total). The concentrations mea -
sured in May and June of 2009 were consistently lower for all congeners, and at all measurement locations, than
those measured in January, February, April, October, and November 2007, with a larger proportion of nondetects
than in 2007 (206/918, 22%, versus 126/1173, 11%). Again, 1,2,3,7,8,9-hexaCDF was the most frequent nondetect
(only 4/54 samples measurable).
CHPPM also provided the committee with PCDD/PCDF sample data for 9 samples collected on 9 dates in
2006, but no location for these samples was given. At JBB, the distributions of concentrations of total PCDD/Fs
(the sum of the seventeen 2,3,7,8-chlorinated congener concentrations) and individual congeners at each loca -
tion are approximately lognormal with high correlations between congeners. In the 2007 measurements, there is
no significant difference in individual congeners or in total PCDD/F between the January–April and October–
November measurements at each location, although there is a slight trend for the January–April concentrations
to be higher than the October–November concentrations at the guard tower/transportation field and H-6 housing/
CASF locations.
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GA: Agency for Toxic Substances and Disease Registry. http://www.atsdr.cdc.gov/toxprofiles/tp.asp?id=587&tid=109
(accesed March 3, 2011)
EPA (U.S. Environmental Protection Agency). 1990. Technical assistance document for sampling and analysis of toxic organic
compounds in ambient air. Washington, DC: Atmospheric Research and Exposure Assessment Laboratory.
NRC (National Research Council). 2010. Review of the Department of Defense Enhanced Particulate Matter Surveillance
Program report. Washington, DC: The National Academies Press.
Taylor, G., V. Rush, A. Peck, and J. A. Vietas. 2008. Screening health risk assessment burn pit exposures Balad Air Base, Iraq
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