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DISCLAIMER
This material has been funded wholly or in part by the United States
Environmental Protection Agency under Contract 68-03-4006 to PEI Associates, Inc.
It has been subject to the Agency's review and it has been approved for publication
as an EPA document. Mention of trade names or commercial products does not
constitute endorsement or recommendation for use.
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for asbestos, the decision to select an air sampling protocol for determining
successful abatement completion is left to the abatement project manager. Thus, the
determination of work-area cleanliness depends on which method is chosen for
measuring asbestos fibers.
Although the Purple Book reflects current EPA guidance for work practices and
procedures to be used in performing asbestos-abatement projects, the book's
guidance on clearance testing has been superseded by a procedure set forth in the
final rule (52 CFR 41821) promulgated under the Asbestos Hazard Emergency
Response Act (AHERA) of 1986. The final rule sets forth TEM as the analytical
method to be used for analysis of samples taken for clearance air monitoring on
projects involving removal of greater than 150 square feet or 260 linear feet of
asbestos. The final rule also specifies a procedure for determining when an
asbestos site is sufficiently clean for the critical coriainment barriers to be removed.
The procedure involves collecting five samples from inside and five samples from
outside the abatement work area but not necessarily outside of the building. The
average of the work area concentrations must be statistically (Z-test) no larger than
the average of measured concentrations outside the work area.
This report presents a statistical evaluation of airborne asbestos data collected
before, during, and after removal of ACM at three abatement projects that were
conducted in accordance with the procedures recommended in the Purple Book.
This study assesses the effectiveness of EPA-recommended work practices and
procedures for controlling asbestos fiber concentrations outside the work area during
abatement. It also examines whether an abated site meets both the TEM and PCM
release criteria. For one abatement project, the report also presents 1) a comparison
of TEM analysis on 0.4-nm pore polycarbonate and 0.8-^m pore mixed cellulose
ester membrane filters, and 2) asbestos fiber concentrations in discharge air from a
HEPA-filtered negative air pressure filtration system.
OBJECTIVES
The -Allowing were the primary objectives of the study:
Determine the effectiveness of containment barriers in preventing the
release of as', estos fibers outside of the work area.
• Determine the effectiveness of final cleanup procedures.
• To evaluate the TEM clearance criteria for both the t-test and to the extent
that the data allow, the Z-test.
Determine if an abated site meets both TEM and PCM clearance criteria
and evaluate whether PCM provides false positives for clearance
decisions.
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Determine if 0.8-nm pore size mixed cellulose ester and 0.4-nm pore size
polycarbonate membrane filters produce equivalent estimates of airborne
asbestos concentrations.
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SECTION 2
CONCLUSIONS AND RECOMMENDATIONS
CONCLUSIONS
The principal conclusions reached during this study are presented below:
1. Asbestos concentrations measured outside the work area before, during,
and after abatement at Sites 1 and 3 did not vary significantly. This
indicates that the containment barriers at these two sites were effective in
preventing the release of asbestos fibers outside the work area. At Site 2,
however, the asbestos concentrations measured after abatement were
significantly higher than those measured before and during abatement.
The mean asbestos concentrations after abatement was approximately 80
times higher than the mean concentration before abatement. These
elevated asbestos concentrations suggest that 1) the containment barrier
was not effective at this site, 2) work practices recommended in the Purple
Book3 were not followed, or 3) asbestos-containing material outside the
abatement containment was disturbed resulting in elevated asbestos
concentrations in that area.
2. At Site 1, asbestos concentrations did not increase significantly after
abatement and were not significantly higher than the ambient
concentrations. At Sites 2 and 3, however, asbestos concentrations did
increase significantly after abatement and were also significantly higher
than ambient concentrations. The higher postabatement concentrations
may be attributable to improper or inadequate implementation of final
cleanup procedures, or they may be due to sampling conditions (i.e., static
conditions in the preabatement phase versus aggressive conditions in the
postabatement phase), or both.
3. Sites 1, 2, and 3 passed the TEM clearance criteria for both the t-test
recommended in the Purple Book and Z-test specified in the final rule
under AHERA. At Site 2, the increase in the postabatement asbestos
concentration outside the work area, as noted in the preceding discussion,
enabled the site to pass both clearance tests. Conversely, a comparison of
the postabatement concentrations inside the work area with ambient
concentrations resulted in the site failing both clearance tests. This single
incident identifies a serious limitation in the comparison of postabatement
asbestos concentrations inside the work area with those outside the work
area.
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4. Sites 1, 2, and 3 passed the TEM clearance criteria based on both the t-test
(Purple Book) and the Z-test (AHERA final rule). Sites 1 and 2 also passed
the PCM clearance criterion (0.01 f/cm3); however, Site 3 failed. Thus, this
study identified a false positive PCM clearance situation where a site failed
PCM and passed TEM.
The differences in conclusions reached by the two protocols are probably
due to the limited ability of PCM to distinguish asbestos from nonasbestos
materials. Airborne fiber concentrations estimated by PCM reflect total
fiber concentrations, not just asbestos fiber concentrations; therefore, they
may lead to erroneous conclusions regarding abatement clearance.
5. The TEM analysis of 69 paired 0.8 |im pore size mixed cellulose ester and
0.4 |im pore size polycarbonate membrane filters revealed a statistically
significant difference in asbestos concentrations on the two filter types.
(The Purple Book recommends that 0.4 urn pore size polycarbonate filters
or 0.8 |im pore size mixed cellulose ester filters be used to collect airborne
asbestos fibers, whereas, AHERA specifies the same filter types but a
different pore size (0.45 jam) for the mixed cellulose ester filters.) Asbestos
concentrations on 0.4 ^m pore size polycarbonate filters were significantly
higher than those on 0.8 u.m pore size mixed cellulose ester filters. The
two types of filters do not produce equivalent estimates of airborne
asbestos concentrations. The difference in asbestos concentrations may
be due to the differences in the pore sizes or chemical composition of the
two types of filters.
RECOMMENDATIONS
Because the elevated levels outside the containment area at Site 2 would have
allowed a contaminated site to pass under the AHERA sampling strategy, monitoring
of contamination level outside the work area during abatement or after abatement
should be strongly considered as a prerequisite to using this area as a clearance
reference point. If additional monitoring is not considered reasonable, the guidance
should be revised to emphasize the importance of the location of the "outside"
samples.
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SECTION 3
STUDY DESIGN AND EXPERIMENTAL METHODS
SITE DESCRIPTIONS
The objectives of this study, which are formally presented in Section 1, stipulate
that air monitoring will be conducted before, during, and after removal of ACM at
three asbestos-abatement sites. The three sites selected, which are all school
buildings, met the following criteria:
1. No significant abatement of ACM had occurred inside the building site
within the last 12 months.
2. Each abatement site was in a different geographical location or building.
3. The abatement project involved the removal of spray-applied asbestos-
containing fireproofing from structural members and decking.
4. The abatement project was governed by written specifications that comply
with the minimum requirements in the latest EPA guidance document (the
Purple Book3).
5. The building owner and abatement contractor agreed to cooperate with the
EPA and to provide access to selected areas of the building.
During the site selection process, representative bulk samples of the ACM to be
removed at each candidate site were collected in accordance with the EPA-
recommended sampling scheme for friable surfacing materials and analyzed by
polarized light microscopy.4'5 The type and percentage (by weight) of asbestos in
the spray-applied fireproofing removed at the three sites were as follows: 5 to 10
percent chrysotile at Site 1, 20 to 25 percent chrysotile at Site 2, and 20 to 60 percent
chrysotile at Site 3. The abatement efforts at Sites 1, 2, and 3 involved the removal of
approximately 10,000, 17,000, and 5,000 square feet, respectively, of surface area
treated with the spray-applied material.
The abatement contractors prepared the work areas, removed the asbestos-
containing fireproofing, and conducted decontamination activities in accordance with
the latest EPA guidance (the Purple Book). The abatement activities were performed
in three distinct stages: preparation, removal, and decontamination. Work areas
were prepared by removing all movable objects; turning off the ventilation and
electrical systems; sealing off all air ducts and openings; covering the floors, walls,
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and immovable objects with plastic sheeting; installing HEPA-filtered, negative-
pressure air filtration systems; and constructing two entrance and egress
contamination-control facilities-one with showers and change rooms for personnel
and the other for waste-material handling. Suspended ceilings and carpeting were
either removed and disposed of as contaminated waste or cleaned and disposed of
by conventional means.
Workers wearing full protective clothing and approved respiratory protection
removed the fireproofing by first wetting the material with an amended water solution
and then scraping it off. The asbestos-containing debris was placed in double 6-mil
polyeliiylene bags and disposed of at an approved sanitary landfill. All substrate
surfaces from which asbestos was removed were wire-brushed and wet-wiped
repeatedly to remove as much of the fireproofing material as possible. All stripped or
potentially contaminated surfaces were sprayed with an asbestos sealant to bond
any residual fibers to the substrate. During decontamination of the work area, all
loose debris was removed, as was the plastic sheeting from the walls and floors.
Decontamination also involved two complete final cleanups entailing wet-wiping or
mopping of the walls and floors. At Site 1, an 8-hour period elapsed between the
final cleanings; at Site 2, a 24-hour period elapsed between cleanings. The work
areas were then visually inspected to assure the absence of debris and visible dust
on surfaces. When the work area passed a thorough visual inspection and air
monitoring showed that the total fiber concentrations were less than 0.01 1/cm3 (by
phase contrast microscopy), all remaining critical containment barriers (on windows,
doors, and vents) were removed, and the area was considered acceptable for
reoccupancy.
SAMPLING STRATEGY
At each of the three abatement sites, area air samples were collected before,
during, and after removal ol the spray-applied asbestos-containing fireproofing.
Samples were collected inside the work area (i.e., the abatement area); outside the
work area (i.e., the perimeter area outside the abatement area); and ambient air (i.e.,
outside of the building). Side-by-side samples were collected at each location for
separate PCM and TEM analysis. The sampling matrix is presented in Table 1.
The preabatement air samples were collected inside and outside the work area
before the containment barriers were constructed. The sampling was conducted
under static conditions (i.e., activity in the area was minimal and the heating,
ventilation, and air-conditioning system was not in operation).
During the removal phase of the abatement, air samples were collected at
scheduled intervals outside the work area under static sampling conditions. Table 2
shows the sampling scheme that was followed:
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TABLE 1. AIR SAMPLING MATRIX
00
Location and number of samples
Inside work area
Site
t
2
3
Total
Abatement phase PCM
Before
During
After
r
Total
Before
During
After
Total
Before
During
After
Total
Samples
10
0
5
15
5
0
5
10
8
0
7
15
40
TEM
10
0
5
15
5
0
5
10
8
0
7
15
40
Outside
PCM
12
31
5
48
5
31
7
43
3
61
5
69
160
work area Outdoors
TEM
12
31
5
48
5
31
7
43
3
49
2
54
145
PCM
3
4
5
12
5
5
0
10
3
0
3
6
28
TEM
3
4
4
11
5
5
0
10
3
0
3
6
27
Field blanks
PCM
3
4
1
8
1
3
1
5
2
11
1
14
27
TEM
3
5
1
9
1
3
1
5
2
10
1
13
27
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TABLE 2. SAMPLING SCHEME FOR SAMPLING OUTSIDE WORK AREA
UNDER STATIC SAMPLING CONDITIONS
Removal Phase Sampling Phase
Site 1 November 13-24, 1987 November 13, 18. 19, 20, 21, 24
Site 2 April 6-8, 1987 April 6,7,8
Site 3 August 20 - September 12 August 20, 31 - September 1, 2,
3,4,8,9,10,11,12-
Th e postabatement air samples outside the work area also were collected
under static sampling conditions. The postabatement air samples inside the work
area were collected under aggressive sampling conditions. The aggressive
sampling conditions were created in the work area by an initial "blowdown" of all
horizontal and vertical surfaces with a hand-held electric-powered leaf blower,
followed by the use of floor fans to generate continuous air turbulence throughout the
duration of the sampling period.
At Site 3, additional limited sampling was conducted during the removal phase
to determine the asbestos fiber concentrations in the discharge air of the operating
HEPA-filtered negative-air filtration systems.
SAMPLING METHODS
Area Air Samples
Two side-by-side area air samples were collected at each sampling location
inside and outside the work area and outdoors. Each pair of samples consisted of a
25-mm, 0.4-u.m pore size, Nuclepore polycarbonate filter and a 25-mm, 0.8-u.m pore
size, Millipore mixed cellulose ester filter. Each 25-mm filter was mounted on a 5-jim
pore size, mixed cellulose ester, backup diffusing filter and cellulose support pad and
was contained in a three-piece cassette with a 50-mm conductive cowl and face cap.
The base and cowl sections of the cassettes were sealed with vinyl adhesive tape to
prevent air filtration through the seams of the cassettes during sampling. The filter
cassettes were positioned 4 to 5 feet above the floor and were arranged in a
horizontal line by clipping them to a sturdy stand. The filter cassettes were placed
approximately 5 cm apart and were oriented in the same direction with the filter face
angled slightly downward. During sampling, the face cap was removed to expose
the full face of the filter to the air stream.
The filter assembly was attached to an electric-powered vacuum pump. An
inline calibrated precision rotameter was used to regulate the air-flow rate through
the filter assembly at 8 to 12 liters per minute (l/min).
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The air samples were generally collected for a period of approximately 6 to 9
hours to achieve a minimum air volume of 3000 liters for each sample; however, a
limited number of samples were collected for periods extending up to 17 hours,
which yielded air volumes of approximately 11,000 liters. At the end of the sampling
period, filters were turned upright before being disconnected from the vacuum pump
and were stored in this position.
Ispkinetic Air Samples-Negative Air Filtration Unit
An isokinetic sampling train was designed to determine asbestos
concentrations in the exhaust duct discharge air from a negative-air filtration unit.
Isokinetic sampling is a method of sampling in which the velocity of air entering the
sample nozzle (Vn) is the same as the velocity of the air stream (Vs). That is, the
sample nozzle,tip opening area (An, ft2) and sample volume flow rate (Vm, ft3) must
be adjusted to obtain a velocity (Vn => Vm/n) equal to the air stream velocity (Vs) at the
sampling point. The sampling constraint Vn =» Vs is called isokinetic or equal velocity
sampling.
The isokinetic sampling train consisted of a nozzle (approximately 10 cm in
length); a three-piece filter cassette containing a 25 mm diameter membrane filter; a
precision flow control device; and an electric powered vacuum pump. The nozzle
was mounted directly to the filter caco«=t*e to minimize sample loss, and the assembly
was positioned in the duct with the nozzle at the centerline of the duct. Two side-by-
side air samples were collected during each test. Each pair of samples consisted of
a 25-mm, 0.4-jim pore size Nuclepore polycarbonate filter and a 25-mm, 0.8-pore
size Millipore mixed cellulose ester filter. Each 25-mm filter was mounted on a 5-jam
pore size, mixed cellulose ester, backup diffusing filter and cellulose support pad.
The sampling flow rate was based on duct velocity measurements made before
each test. The centerline air velocity was monitored throughout each test by a
calibrated velometer, and the flow rate through the system was adjusted to
accommodate the isokinetic sampling procedure. An in-line precision calibrated
rotameter was used to regulate the air-flow rate through the filter assembly at 7.5 to
8.3 liters/min (mean 7.7 ± 0.33 liters/min). The sampling period range from 5.1 to
18.6 hours (mean 9.8 ± 6.6 hours) to achieve an air volume of 2.33 to 9.03 cubic
meters (mean 4.58 ± 3.20 m3).
ANALYTICAL METHODS
The mixed cellulose ester membrane filters were analyzed by phase contrast
microscopy (PCM), and the polycarbonate membrane filters were analyzed by
transmission electron microscopy (TEM). The PCM and TEM analytical protocols are
presented in the Quality Assurance Project Plan prepared for this research study.6
The mixed cellulose ester filters were prepared and analyzed for total fibers by
PCM in accordance with NIOSH Method 7400.7 All fibers or fibertike particles
measuring at least 5 ^m in length and having a 3:1 length-to-width aspect ratio were
10
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counted in accordance with the 7400-A counting rules. Because NIOSH Method
7400 is nonspecific for asbestos, all the fibers counted cannot be assumed to be
asbestos, as every fiber or.fiberlike particle meeting the NIOSH dimension criteria
was counted. Analyses were performed by PEI Associates, Inc., in Cincinnati, Ohio.
The polycarbonate filters were prepared and analyzed for asbestos fibers by
TEM in accordance with the Yamate Method.8 The Yamate methodology8 describes
three levels of TEM analysis. Two of these levels are briefly summarized here. Level
I TEM analysis involves examination of the particulates deposited on the sample filter
by a 100-kV transmission electron microscope. Asbestos structures (fibers, bundles,
clusters, and matrices) are counted, sized, and identified as to asbestos type
(chrysotile, amphibole, ambiguous, or no identity) by morphology and by observance
of the selected arec electron diffraction (SAED) patterns. The width-to-length ratio of
each counted particle is calculated and recorded. Level II TEM analysis consists of a
Level I analysis plus chemical elemental identification by energy-dispersive
spectrum (EDS) analysis. Energy-dispersive analysis is used to determine the
spectrum of the x-rays generated by an asbestos structure. X-ray elemental analysis
is used for further categorization of the amphibole fibers, identification of the
ambiguous fibers, and confirmation or validation of chrysotile fibers. All
polycarbonate filter samples collected in this study were analyzed by Level II TEM.
Three laboratories performed the TEM analysis on the field samples under
separate contract with EPA's Water Engineering Research Laboratory (WERL) in
Cincinnati. The complete set of samples from each abatement site was assigned to a
different analytical laboratory designated by the EPA Technical Project Monitor: Site
1 samples to Chatfield Technical Consulting Limited in Mississauga, Ontario,
Canada; Site 2 samples to R. J. Lee Group, Inc. (formerly Energy Technology
Consultants) in Monroeville, Pennsylvania; and Site 3 samples to Battelle
Laboratories, Columbus, Ohio.
Battelle Laboratories also performed TEM Level II analysis on the mixed
cellulose ester filter samples collected at abatement Site 3. For consistency across
all sites, statistical comparisons were made with polycarbonate filter samples.
QUALITY ASSURANCE
The Quality Assurance Project Plan (QAPP) contains the complete details of the
quality assurance procedures followed during this research project.6 These
procedures are summarized in the following subsections.
Sample Chain-of-Custody
Sample chain-of-custody procedures were an integral part of both sampling and
analytical activities during this study. They were implemented for all air and bulk
samples collected. The applied field custody procedures documented the existence
of a sample from its time of collection until its receipt by the analytical laboratory.
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Internal laboratory records then documented the custody of the sample through its
final disposition.
Standard sample custody (traceability) procedures were used during this
project. Each sample was labeled with a unique project identification number, which
was recorded in the field log book along with other information specified by the
QAPP.
Quality Assurance Sample Analyses
Specific quality assurance procedures used to ensure the accuracy and
precision of the TEM and PCM analyses of air samples included the use of laboratory
and field blanks and replicate analyses. Laboratory blanks are filters chosen before
the start of field work. These blanks are analyzed by the analytical laboratory to
check for filter contamination. Field blanks are filters taken into the field and handled
in the same manner as exposed air sample filters to check for contamination that
might not be a result of air sampling. Replicate analysis refers to analysis of the
same sample twice by the analytical laboratory. The degree of agreement between
the two analyses indicates the level of precision in the laboratory analysis
procedures.
Laboratory blanks--
Two laboratories (McCrone Environmental Services, Inc., Norcross, Georgia,
and R. J. Lee Group, Inc., in Monroeville, Pennsylvania) analyzed 5 percent of the
total number of polycarbonate filters and 5 percent of the total number of mixed
cellulose ester filters used in the 1987 field studies by TEM Level II in accordance
with the Yamate procedure.8 The polycarbonate filters were all from the same lot.
The filters were considered "acceptable" for use if the average asbestos structure
count per 10 grid openings was less than 3. If the average asbestos structure count
for the group exceeded 3 asbestos structures per 10 grid openings, the entire lot of
filters was considered contaminated. The TEM analysis of the polycarbonate filter
laboratory blanks showed background filter contamination of 1.8 asbestos structures
per 10 grid openings (or 180 asbestos structures in 1000 grid squares examined).
The TEM analysis of tiie mixed cellulose ester filter laboratory blanks showed
background filter contamination of 0.12 asbestos structure per 10 grid squares (or 12
asbestos structures in 1000 grid openings examined). Therefore, the analysis of the
laboratory blanks showed that the background asbestos filter contamination was
within specified limits.
The mixed cellulose ester filters were pretested by PCM analysis before their
use in the field in the same manner as that described for the polycarbonate filters.
The filters were from the same lot. PEI Associates, Inc., Cincinnati performed the
prescreening analyses. The analysis of the laboratory blanks indicated that
background filter contamination was not a problem.
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Field blanks--
Ouring setup of the air sampling pump, preloaded filter cassettes were selected
as field blanks. These filters were labeled and handled in a similar manner as the
sample filters were, but they were not attached to the sampling pump. Field blanks
for both polycarbonate and mixed cellulose ester filters were collected at each of the
three abatement sites. A total of 27 polycarbonate filter field blanks were collected at
Sites 1, 2, and 3 and analyzed by TEM Level II. Table 3 presents the results of these
analyses.
TABLES. RESULTS OF ANALYSES OF POLYCARBONATE
FILTER FIELD BLANKS
Asbestos structures
Site
1
2
3
Number of
field blanks
9
5
13
Total
number
21
0
9
Blank Guideline
Average number
per 1 0 grid
openings
2.3
0
0.69
3.0
Range
per 10 grid
openings
0-6
0
0-5
Therefore, the analysis of the field blanks showed that asbestos filter contamination
was within the guideline of 3 asbestos structures average per 10 grid openings.
A total of 10 mixed cellulose ester filter field blanks were collected and analyzed
by TEM Level II. An of the mixed cellulose ester filters were collected at Site 3. No
asbestos fibers were detected on any of the filters.
A total of 27 mixed cellulose ester filter field blanks were collected and analyzed
by PCM (NIOSH Method 7400). Table 4 presents the results of these analyses.
TABLE 4. RESULTS OF ANALYSES OF MIXED CELLULOSE
ESTER FILTER FIELD BLANKS
Total fibers
Site
1
2
3
Number of
field blanks
8
5
14
Total
nunber
5.5
0
17.5
Average number
per 100 grid
openings
0.69
0
1.3
Range
per 100 grid
openings
0-1.5
0
0-4.5
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All sample concentrations determined by PCM were blank-corrected by the
laboratory; i.e., the fiber contamination level (fibers per 100 fields) was subtracted
from the field samples before the sample concentration (f/cm3) was calculated.
Replicate analysis--
Eleven air samples v=re selected at random to investigate within-laboratory
TEM analysis performance. The samples were reanalyzed by the original laboratory
(replicate analysis). Table 5 presents the results of the original and replicate
analyses. There was no evidence of inconsistency among the two sets of analyses.
A Wilcoxon signed rank test10 did not detect any significant tendency for any one
analysis (original or replicate) to give higher or lower fiber counts (p = 0.820).
STATISTICAL ANALYSIS METHODS
The data were grouped for each site by abatement phase (before, during, and
after); location of sample (inside the work area, outside the work area, and ambient);
and analytical protocol (TEM and PCM). The data were then tested for normality by
using the Shapiro-Wilk statistic to determine an appropriate statistical analytic
approach for the comparisons.9 Although most of the TEM data suggested
reasonable normality, most of the PCM data were non-normal.
Because the test for normality was on five or fewer samples (which decreases
the power of the test to detect aberrations from normality) and to be consistent for all
three abatement sites and analytical procedures with respect to analytical approach,
nonparametric procedures were chosen to make all comparisons of interest.
Nonparametric procedures analyze the relative ranks of the data rather than actual
data values and do not require the normality assumption of the parametric
procedures.
Tiie only exception to the use of nonparametric procedures was the TEM
clearance comparison of postabatement samples inside the work area with those
outside the work area. The Purple Book recommends that this comparison be
conducted with a Student's t-test; the final rule for AHERA requires that this
comparison be conducted with a Z-test. Because all three sites used negative*
pressure air filtration systems during abatement and the makeup or "background" air
came from other parts of the building rather than directly from outdoors, the
postabatement samples inside the work area were compared with the postabatement
samples outside the work area but within the building.3
Samples with a fiber (PCM) or structure (TEM) count of zero were assigned an
estimated airborne concentration of 0 structures per cubic centimeter (s/cm3). A
concentration of 0 s/cm3 was used in all summary statistic calculations and statistical
analyses except the t-test and Z-test used for TEM clearance. The t-test and Z-test
are standard comparisons of means for data that are normally distributed. Because
these tests are based on a log transformation of the data, the Purple Book and
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TABLE 5. COMPARISON OF AIRBORNE ASBESTOS CONCENTRATIONS
ON ORIGINAL AND REPLICATE TEM ANALYSES
Original
No. of fibers
8
10
6
8
15
0
5
13
9
2
5
f/cm3
0.00990
0.01509
0.01013
0.00956
0.01965
0
0.00827
0.02115
0.02943
0.00254
0.00683
Replicate
No. of fibers
1
13
9
7
4
0
13
11
14
2
3
f/cm3
0.00124
0.01962
0.01519
0.00837
0.00524
0
0.02150
0.01790
0.04578
0.00254
0.00410
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AHERA suggests that 0 concentrations be replaced by the analytical sensitivity for
the sample before the t-statistic and Z-statistic are calculated. (The analytical
sensitivity for TEM, also referred to as the detection limit, is the estimated airborne
structure concentration calculated when a single structure is counted in a sample.)
When more than one analysis was completed on a single filter, the average of
these results was used in the statistical analysis.
Summary statistics (arithmetic mean and standard deviation) were calculated
for each site by abatement phase (before, during, and after), location of sample
(inside the work area, outside the work area, and ambient), and microscopic
technique (TEM and PCM).
Statistical analyses were designed to address each of the following objectives
for samples analyzed by PCM and TEM:
Comparison of Fiber Concentrations Outside the Work Area Before. During, and After
Abatement
The Krjskall-Wallis one-way analysis of variance test was used to examine the
differences between airborne fiber concentrations outside the work area before,
during, and after the abatement activity.10 When overall differences were detected,
Dunn's multiple comparison procedure, which is based on the Kruskall-Wallis rank
sums, was used to identify where the differences occurred.10
Comparison of Fiber Concentrations Inside the Work Area Before and After
Abatement
The Wilcoxon rank sum test was used to examine the differences between
airborne fiber concentrations inside the work area before and after the abatement
activity.10 It is important to note that static sampling techniques were used for
preabatement sampling, whereas aggressive sampling techniques were used for
postabatement sampling inside the work area. For this reason, this is not strictly a
comparison of preabatement and postabatement concentrations inside the work
area, but rather a comparison of prestatic and postaggressive sampling
concentrations.
TEM Clearance Comparison
All three sites in this study used negative-pressure air filtration systems during
the abatement activity. Thus, for clearance comparison purposes it is appropriate to
compare postabatement concentrations inside the work area with postabatement
concentrations outside the work area (but inside the building). The averages of
inside and outside log concentrations are compared by using the Studf nt's t-test, as
described in the Purple Book. As noted earlier, the samples with an asbestos count
of 0 structures were assigned a concentration equal to the analytical sensitivity for
that sample (defined as the concentration that would be present if a single fiber were
detected). If the mean asbestos concentration inside the work area is not statistically
16
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greater than the mean asbestos concentration outside the work area (but inside the
building), the abatement site passes the clearance test.
Although the monitoring data (Table 4) are not totally consistent with the
requirements in the final rule (October 30,1987; 52 FR 41826) under AHERA, the
postabatement concentrations inside the work area and those concentrations outside
the work area (but inside the building ) are also compared using the Z-test to
determine if abated work areas meet the AHERA TEM clearance criteria. The Z-test
is a standard comparison of means for data that are normally distributed with a
known variance. Because it is based on a log transformation of the data, the
particular form of the Z-test required under the AHERA final rule (October 1987; 52
FR 41286) specifies that 0 concentrations are to be replaced by the analytical
sensitivity before the Z statistic is calculated. The abatement work area passes the
test if the asbestos concentrations inside the work area are not statistically higher
than the asbestos concentrations outside the work area. The clearance test is based
on a minimum of five samples inside the abatement work area and five samples
outside the abatement v/crh area to control the false negative error rate. "Outside"
means outside the abatement work area, but not necessarily outside the building.
PCM Clearance Comparison
The release criterion the Purple Book recommends for use with PCM involves
comparing postabatement fiber concentrations inside the work area with the PCM
limit of reliable quantitation (approximately 0.01 f/cm3 for 3000 liters of air sampled).
Abatement activity for which PCM protocols are used is considered complete if the
airborne asbestos concentration for each sample concentration is no higher than
0.01 f/cm3.
Comparison of Concentrations Inside the Work Area With Ambient Air
Concentrations After Abatement
The Wilcoxon rank sum tost was used to determine whether asbestos
concentrations inside the work area after abatement were statistically greater than
postabatement ambient air concentrations.
Comparison of TEM Analysis on 0.4-f.im Pore-Size Polycarbonate and 0.8-}im Fore-
Size Mixed Cellulose Ester Filters
The Wilcoxon signed rank test for paired samples was used to determine if a
statistically significant difference in airborne asbestos fiber concentration existed
between the filter types.
The Purple Book recommends that 0.4-nm pore size polycarbonate filters
(preferred) or 0.8-|im pore size mixed cellulose ester filters be used to collect
airborne asbestos fibers for TEM analysis. The final rule under AHERA specifies the
same sample filter types, but a difvorent pore size (0.45-nm) for the mixed cellulose
ester filter.
17
-------
SECTION 4
RESULTS AND DISCUSSION
Summary statistics (arithmetic mean and standard deviation) for Sites 1, 2, and
3 are presented in Tables 6, 7, and 8, respectively. The results are presented for
Sites 1, 2, and 3 by abatement phase (before, during, and after) and location of
sample (inside the work area, outside the work area, and ambient). The mean
asbestos concentrations are graphically presented for Sites 1, 2, and 3 according to
abatement phase and location of sample in Figure 1. The individual air sampling
results by TEM analysis are listed in Appendix A and those by PCM analysis are
listed in Appendix B. The statistical evaluation of the data for each site is presented
according to the objectives stated in Section 3.
SITE 1
Comparison of Fiber Concentrations Outside the Work Area Before. During, and After
Abatement
The Kruskall-Wallis test revealed no statistically significant differences in the
airborne asbestos concentrations outside the work area between the three abatement
phases (Figure 2) for those samples analyzed by TEM (p = 0.773). The test, however,
did reveal a statistically significant difference in fiber concentrations between the three
phases (Figure 3) for those samples analyzed by PCM (p = 0.0002). The fiber
concentrations outside the work area both during abatement and after abatement were
significantly greater than the fiber concentrations before abatement (Table 6).
The apparent differences in the conclusions reached by the two analytical
protocols confirm the two serious limitations in the use of PCM for measuring
airborne asbestos. First, PCM cannot distinguish asbestos from nonasbestos fibers;
all particles of the required length and aspect ratio are counted. Second, only
particles >0.25 jim in dimeter are detected and only particles 25 urn in length are
counted. These lim/M-yM in PCM analysis are illustrated in Figures 4, 5, and 6,
which show the struc^L characteristics (length and diameter) of particles in
samples collected outside the work area and analyzed by TEM. The asbestos
concentrations are based primarily on particles outside the PCM window (i.e.,
particles <0.25 jim in diameter and <5 urn in length), which PCM resolution and
counting protocols will not detect, Hence, differences in mean PCM fiber
concentrations among the three abatement phases at Site 1 are probably due to
nonasbestos particles.
18
-------
TABLE 6. SUMMARY STATISTICS OF TEM AND PCM ANALYSES FOR SITE 1
Airborne concentration, f/cm3
Location
Ambient
Perimeter
Work area
Ambient
Perimeter
Work area
Ambient
Perimeter
Work area
Sample
size
3
12
10
4
31
0*
4
5
5
TEM
Standard
Mean deviation
Preabatement
0.0041 0.0009
0.0052 0.0035
Sample
size
Phase
3
12
0.0091 0.0053 10
During Abatement Phase
0.0034 0.0040
0.0089 0.0098
•
Postabatement
0.0067 0.0045
0.0057 0.0046
0.0056 0.0039
4
31
0*
Phase
5
5
5
PCM
Standard
Mean deviation
0.0007 0.0006
0.0003 0.0006
0.0000 0.0000
0.0008 0.0010
0.0023 0.0019
0.0002 0.0004
0.0022;; 0.0011
0.0015 0.0010
No samples were collected.
19
-------
TABLE 7. SUMMARY STATISTICS OF TEM AND PCM ANALYSES FOR SITE 2
Airborne concentration, f/cm3
Location
Ambient
Perimeter
Work area
Sample
size
5
5
5
TEM
Standard
Mean delation
Preabatement
0.0011 0.0016
0.0030 0.0030
0.0367 0.0739
PCM
Sample
size Mean
Phase
5 0.0012
5 0.0014
5 0.0012
Standard
d
-------
TABLE 8. SUMMARY STATISTICS OF TEM AND PGM ANALYSES FOR SITE 3
Airborne concentration, f/cm3
Location
Ambient
Perimeter
Work area
Sample
S'ze
3
3
8
TEM
Standard
Mean deviation
PreabatQment
0.0000 0.0000
0.0008 0.0014
0.0001 0.0004
PCM
Sample
size Mean
Phase
3 0.0020
3 0.0040
8 0.0020
Standard
deviation
0.0017
0.0010
0.0011
During Abatement Phase
Ambient
Perimeter
Work area
Ambient
Perimeter
Work area
0'
49
0*
3
2
7
-
0.0129 0.0270
* *
Postabatement
0.0000 0.0000
0.0028 0.0039
0.0023 0.0019
0*
61 0.0106
0*
Phase
3 0.0107
5 0.0074
7 0.0080
-
0.0133
-
0,0015
0.0068
0.0031
No samples were collected.
21
-------
Average Airborne Asbestos Concentration (s/cm3)
to
to
0.35
0.3
0.25
0.2
0.15
0.05
PRE OUR POST
SITE 1
PRE OUR POST
SITE 2
PRE OUR POST
SITE 3
Work Area
Perimeter
Outdoor
Figure 1. Mean airborne asbestos concentrations before, during, and
after abatement for samples analyzed by TEM at sites 1, 2,
and 3.
-------
M
OJ
DURING
ABATEMENT. PHASE
BOB AMBIENT
INSIDE WORK AREA
PERIMETER
POST
Figure 2. Mean airborne asbestos concentrations before, during, and
after abatement for samples analyzed by TEM at site t.
-------
10
0.0026
0.0024
0.0022
o
o
PRE
DURING
ABATEMENT PHASE
ooo AMBIENT
ooo INSIDE WORK AREA
PERIMETER
POST
Figure 3. Mean airborne fiber concentrations before, during, and
after abatement for samples analyzed by PCM at site t.
-------
10
Ot
STRUCTURE LENGTH. MICROMETERS
o o o , «.
O • • «• — OJ en O
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STRUCTURE DIAMETER. MICROMETERS
METHOD 7400 * * *
HRYSOTILE M » » «
MPHIBOLE B 000
MBIGUOUS F OGO
MBIGUOUS C N N N
ON ASBESTOS M Y Y Y
1 CHRYSOTILE F o o o 1 CHRYSOTILE B
1 CHRYSOTILE C x x x \ AMPHIBOLE F
1 AMPHIBOLE M o a o 1 AMPHIBOLE C
1 AMBIGUOUS B z z z 1 AMBIGUOUS M
1 NON ASBESTOS F V V V 1 NON ASBESTOS B
* NON ASBESTOS C
Figure 4. Plot of structure length and diameter for preabatement
air samples coiiected outside the work oreo (perimeter)
for site 1.
-------
PCM Method 7400
ro
o>
to
(XL
UJ
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STRUCTURE DIAMETER. MICROMETERS
A A
8 8
C C
W W
PCM METHOD 7400
1 CHRYSOTILE M
1 AMPHIBOLE B
1 AMBIGUOUS F
1 AMBIGUOUS C
1 NON ASBESTOS M
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1
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CHRYSOTILE F
CHRYSOTILE C
AMPHIBOLE M
AMBIGUOUS B
NON ASBESTOS
NON ASBESTOS
F
C
o o
X X
a a
z z
V V
o
x
a
z
V
1
1
1
1
1
CHRYSOTiLE B
AMPHIBOLE F
AMPHIBOLE C
AMBIGUOUS M
NON ASBESTOS B
Figure 5. Plot of structure length and diameter for oir samples
collected outsjde the work area (perimeter) during the
abatement at site 1
-------
to
to
UJ
o
o:
o
UJ
10.0-
5.6-
1.0
0.56
0.32-
0.18-
O.I-
Method 7400
0
*
*
0.01 0.032 O.i 0.32 1.0
STRUCTURE DIAMETER. MICROMETERS
3.2
10.0
prw uFTHnn 74nn
> + 1 CHRYSOTILE M
A A 1 AMPHIBOLE B
8 8 t AMBIGUOUS F
C C J AMBIGUOUS C
W W t NOW ASBESTOS M
* *
« «
0 0
O 0
N N
Y Y
*
tt
0
o
N
Y
1
1
1
1
1
1
CHRYSOTILE f
CHRYSOTILE C
AMPHIBOLE M
AMBIGUOUS B •
MON ASBESTOS
WON ASBESTOS
F
C
o
x
D
Z
V
o
X
a
z
V
O
X
a
z
V
1
1
1
1
t
CHRYSOTILE B
AMPHIBOLE F
AMPHIBOLE C
AMBIGUOUS M
NON ASBESTOS
B
Figure 8. Pjot of structure length and diameter for post abatement
air samples collected- outside the work area (perimeter)
a t s i t e 1.
-------
Comparison of Fiber Concentrations Inside the Work Area Before and After
Abatement
The Wilcoxon rank sum test revealed no statistically significant difference in
mean airborne asbestos concentration inside the work area before and after
abatement (Figure 2) for TEM-analyzed samples (p = 0.254). The test, however, did
reveal a significant difference in concentrations for the PCM-analyzed samples (p =
0.012). The mean fiber concentration increased approximately 1.5 times after
abatement activity (Figure 3).
As in the case of samples taken outside the work area, the difference found in
the PCM-analyzed samples is probably due to nonasbestos particles (Figure 7). The
TEM-determined asbestos concentrations for the postabatement samples inside the
work area are based on particles outside the PCM resolution window (i.e., particles
that are too small for PCM detection).
Plot of Mean Asbestos Concentrations Based on Minimum Fiber Length
Figures 8 and 9 graphically present the mean asbestos fiber concentrations of
the samples analyzed by TEM based on minimum fiber length for samples outside
the work area and samples inside the work area, respectively. Because PCM
analysis counts only particles >5 |im in length, these plots show the portion of the
total asbestos fiber concentrations consisting of those particles <5 urn in length.
TEM Clearance Comparison
The clearance comparison made with the Student's t-test indicated that the
mean asbestos concentration (0.0056 f/cm3) inside the work area after the
abatement was not statistically greater than the mean asbestos concentration
(0.0057 f/cm3) outside the work area after abatement (t a 0.14, p a 0.447). The
comparison made with the Z-test also showed that the concentrations inside the work
area were not significantly greater than the concentrations outside the work area (Z =
0.14, p a 0.444). Therefore, Site 1 passed both the Purple Book and AHERA TEM
clearance criteria.
Comparison of the postabatement asbestos concentrations inside the work area
with those outside the building also show no statistically significant differences with
either the t-test (t = 0.45, p = 0.666) or the Z-test (Z = 0.45, p = 0.674). Thus, this
comparison would also result in Site 1 passing both Purple Book and AHERA
clearance criteria.
PCM Clearance Comparison
Each postabatement sample collected inside the work area showed a fiber
concentration of <0.01 f/cm3. Therefore, Site 1 also passed the PCM clearance
criteria.
28
-------
M
(O
tA
a:
LLJ
cm
-
x
t—
0
-^
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8
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it o;
• •••""•••'I11**1*'11! .,....,.,,, | ....,.,.. j ..........
0.01 0.032 0.1 0.32 1.0 3.2 10.0
STRUCTURE DIAMETER. MICROMETERS
PCM METHOD 7400 * * * 1 CHRYSOTtLE F o o o 1 CHRYSOTILE B
1 CHRYSOTILE M tt « » 1 CHRYSOTILE C x x x 1 AMPHIBOLE F
\ AMPHIBOLE B 0001 AMPHIBOLE M o o a 1 AMPHIBOLE C
\ AMBIGUOUS F 000! AMBIGUOUS B Z z z \ AMBIGUOUS M
t AMBIGUOUS C W N N • 1 NON ASBESTOS F V V V 1 NON ASBESTOS B
\ NON ASBESTOS M v v v 1 NON ASBESTOS C
Figure 7. Pjot of structure length ond diameter for pos{abatement
oir samples collected inside the work area for site 1.
-------
(0
o
o
o
o
•—
<
I—
z
LU
O
o
o
0.0091
0.0084
0.0077-
0.0070
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0.0056
0.0049
0.0042
0.0035-
0.0028-
0.0021 -
0.0014 -
0.0007-
0.0000-
0
D O O PRC
DURING
POST
-0.0091
-0.0084
-0.0077
-0.0070
-0.0063
0.0056
•0.0049
•0.0042
0.0035
0.0028
0.0021
0.0014
0.0007
0.0000
.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5
MINIMUM LENGTH OF FIBER. MICROMETERS
Figure 8. Plot of meon osbestos concentrations based on minimum fiber
length (or samples collected outside the work area (perimeter)
for site 1.
-------
o
o
o
0.0091-
0.0084-
0.0077
0.0070
0.0063-
0.0056-
0.0049-
0.0042-
0.0035-
0.0028-
0.0021
0.0014-
0.0007:
0.0000-
0.0 0.5
i
1.0
I
t.5
i
2.0
*
2.5
3.0 3.5 4.0 4.5
MINIMUM LENGTH OF FIBER. MICROMETERS
5.0
ODD PR£
POST
•0.0091
0.0084
0.0077
•0.0070
-0.0063
0.0056
•0.0049
-0.0042
-0.0035
0.0028
0.0021
0.0014
0.0007
0.0000
5.5
Figure 9. Plot of raeon osbestos concenlrotions bosed on minimum
fiber length for somples collected inside the work oreo
for site i.
-------
Comparison of Concentrations Inside the Work Area With Ambient Air
Concentrations After Abatement
The Wilcoxon rank sum test indicated that the mean airborne asbestos
concentration for TEM-analyzed samples inside the work area after abatement was
not statistically greater than the mean ambient concentration after abatement (p =
0.635). For PCM-analyzed samples, however, analysis indicated that the mean fiber
concentration inside the work area after abatement was significantly greater than the
mean ambient concentration after abatement (p = 0.038). The mean fiber
concentration inside the work area after abatement was approximately twice as high
as the mean fiber concentration in the ambient air after abatement (Table 6). This
difference found in the PCM-analyzed samples is probably due to the presence of
nonasbestos form particles. As shown in Figure 7, the asbestos fiber concentration
determined by TEM for the postabatement samples inside the work area is based on
particles outside the resolution window of PCM.
SITE 2
Comparison of Fiber Concentrations Outside the Work Area Before. During, and After
Abatement
The Kruskall-Wallis test revealed statistically significant differences in airborne
asbestos concentrations outside the work area between the three abatement phases
(Figure 10) for TEM-analyzed samples (p = 0.0002). The mean asbestos
concentration after abatement was approximately 8 times greater than the mean
concentration during abatement and approximately 80 times greater than the mean
concentration before abatement (Table 7). The asbestos concentrations outside the
work area before abatement were not significantly different from the concentrations
during abatement.
The Kruskall-Wallis test revealed no statistically significant difference in the
mean fiber concentrations between the three abatement phases (Figure 11) for those
samples analyzed by PCM (p = 0.229). The PCM mean fiber concentrations are
considerably lower than the corresponding TEM mean asbestos concentrations
(Table 7) even though PCM counts all fiber types and TEM counts only asbestos
fibers. This suggests that most of the fibers counted by TEM are too small to be
detected by PCM. This corroborates previous findings that PCM estimates of
airborne fiber concentrations do not accurately reflect estimates of asbetos
concentrations based on TEM.3-12
Plot of Mean Asbestos Concentrations Based on Minimum Fiber Lenolh
Figures 12 and 13 graphically present mean asbestos fiber concentrations of
the samples analyzed by TEM based on minimum fiber length for inside-work-area
samples and outside work area samples, respectively. Because PCM analysis
counts only particles >5 p.m in length, these plots show the portion of the total
asbestos fiber concentration consisting of those particles <5 urn in length.
32
-------
b)
DURING
ABATEMENT PHASE
ODD AMBIENT
INSIDE WORK AREA
PERIMETER
POST
figure 10. Mean airborne asbestos concentrations before, during, ond
after abatement for samples analyzed by TEM at site 2.
-------
CO
OUR J NG
ABATEMENT PHASE
a D a AMBIENT
ooo INSIDE WORK AREA
PERIMETER
POST
Figure 11. Mean airborne fiber concent rot ions before, during.
and after abatement for samples analyzed by PCM ot
s i t e 2 . '
-------
Ol
en
o
o.3i ^
0.29
0.26
^ 0.24
^ 0.22
z
o 0.19
< 0. 17
z 0.14
UJ
z 0.12-!
0 0.10,-]
S 0.07-
S 0.05-
0.02-
0,00-
0
.0
i
0.5
1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
MINIMUM LENGTH Of FJ8ER. MICROMETERS
o a o PRE
POST
-0.31
-0.29
0.26
-0.24
0.22
0. 19
0. 17
0.14
0. 12
-0. 10
-0.07
0.05
0.02
0.00
5.0 5.5
Figure 1-2. Plot of mean asbestos concentrations based on minimum
fiber length for samples collected inside the work oreo
for si te
-------
o
C7>
O
O
o
(—
<
o
o
3.0 3.5 4.0
MINIMUM LENGTH OF FIBER. MICROMETERS
ooo PRE
DURING
POST
00
5.0 5.5
figure 13. Plot of meor> asbestos concentrations based on minimum fiber
length lor samples collected outside the work area {perimeter)
for site 2.
-------
Comparisgn of Fiber Concentrations Insidq the Work Area Before and After
Abatement
The Wilcoxon rank sum test revealed a statistically significant difference in the
mean airborne asbestos concentration of TEM-analyzed samples inside the work
area after abatement (p = 0.008). The mean asbestos concentration increased
significantly after abatement (Figure 10). This increase may be attributable to the
difference in sampling conditions (i.e., static sampling conditions in the preabatement
phase versus aggressive sampling conditions in the postabatement phase).11
The test revealed no statistically significant difference in the mean fiber
concentration of PCM-analyzed samples after abatement (p » 0.096) (Figure 11).
TEM Clearance Comparison
The clearance comparison made with the Student's t-test indicated that the
mean asbestos concentration inside the work area after abatement (0.308 f/cm3) was
not statistically greater than the mean asbestos concentration outside the work area
after abatement (0.241 f/cm3) (t = 0.97, p = 0.179). This same comparison made
using the Z-test also showed that the concentrations inside the work area were not
significantly higher than the concentrations outside the work area (Z => 1.26, p =
0.104). Therefore, Site 2 passed both the Purple Book and AHERA TEM clearance
criteria.
Although the site passed both statistical clearance tests, there was a statistically
•:; rjnificant increase in the concentration of airborne asbestos fibers between the
preabatement and postabatement periods. As shown earlier, there was a significant
increase inside the abatement work area (p = 0.008), as well as outside the
abatement area (p = 0.0002). This increase in asbestos concentration outside of the
abatement area enabled the site to pass both the Purple Book and AHERA clearance
criteria. However, comparison of the postabatement inside work area concentrations
with outside building concentrations show statistically significant differences using
both the t-test (t = 17.3, p => 0.0001) and Z-test (Z « 12.4, p « 0.0001). Thus,
comparison of the inside work area concentrations with outside building
concentrations causes the site to fail both Purple Book and AHERA release criteria.
(Because no postabatement ambient air samples were taken outside the building, it
is assumed that postabatement ambient air concentrations are consistent with
preabatement and during-abatement ambient concentrations.)
A single incident such as this is not sufficient basis for proposing a change in
the clearance criteria; however, it does identify a serious limitation of comparing
postabatement asbestos concentrations inside the work area to 4hose outside the
work area, but inside the building. In essence, it demonstrates that a significant
increase in asbestos concentration outside the abatement work area could facilitate
passing of the clearance test. As preabatement samples for TEM analysis typically
are not collected inside or outside of the abatement work area, the increase in
concentration would not be detected. Thus, an asbestos abatement project could
result in an overall increase in the asbestos contamination level in a building.
37
-------
PCM Clearance Comparison
Each postabatement sample collected inside the work area showed a fiber
concentration of <0.01 f/cm3. Therefore, Site 2 also passed the PCM clearance
criteria.
Comparison of Concentrations Inside the Work, Area With Ambient Air
Concentrations After Abatement
No postabatement ambient air samples were collected at this site; however,
ambient air samples were collected both before and during abatement. Tho
Wilcoxon rank sum test indicated no statistically significant difference between the
mean asbestos concentrations of the preabatement ambient samples and the
ambient samples taken during abatement as determined by JEM analysis (p = 0.766)
or PCM analysis (p = 0.690). Therefore, the ambient air results were pooled for
comparison with the postabatement asbestos concentration inside the work area.
Analysis revealed that the mean asbestos concentration inside the work area
after abatement was significantly greater than the overall mean ambient asbestos
concentration for samples analyzed by both TEM (p = 0.0001) and PCM (p = 0.012).
The mean asbestos concentration after abatement as determined by TEM was
approximately 385 times greater than the overall mean ambient concentrations,
whereas the mean fiber concentration determined by PCM analysis inside the work
area after abatement was about twice as high as the overall mean ambient
concentrations (Table 7).
SITE 3
Comparison of Fiber Concentrations Outside the Work Area Before. During, and After
Abatement
The Kruskall-Wallis test revealed no statistically significant differences in
asbestos concentrations outside the work area between the three abatement phases
for samples analyzed by either TEM (p = 0.276) or PCM (p = 0.762) (Figures 14 and
15, respectively).
Although the mean TEM-determined asbestos concentration outside the work
area during the abatement (0.0129 «':;m3) is larger than both preabatement (0.0008
f/cm3) and postabatement (0.0028 f/cm3) mean concentrations, no statistically
significant differences exist in asbestos concentrations among the three abatement
phases (Table 8). The mean asbestos concentration outside the work area during
the abatement is heavily weighted by samples taken on September 11, 1987, which
suggests a breach in the containment barrier. The omission of these samples would
decrease the mean concentration to 0.0064 f/cm3.
38
-------
G>
to
O
O
O
z
O
O
DURING
ABATEMENT PHASE
POST
ODD AMBIENT
ooo INSIDE WORK AREA
PERIMETER
Figure H. Meon airborne asbestos concentrations before, during.
and after abatement for samples analyzed by TEM ot
si te 3.
-------
OUR t NG
ABATEMENT PHASE
ODD AMBIENT
ooo INSIDE WORK AREA
PERIMETER
POST
Figure J5. Mean airborne fiber concentrations before, during.
and after abatement for samples analyzed by PCM at
site 3.
-------
A comparison of median asbestos concentrations between the three abatement
phases actually illustrates the comparability of these concentrations better than an
examination of the mean concentrations. The median concentrations before, during,
and after abatement were 0.0000, 0.0032, and 0.0028 f/cm3, respectively.
Compgrispn of Fiber Concentrations Inside |he Work Area Before and Affer
Abatement
; The Wilcoxon rank sum test revealed a statistically significant difference in the
mean airborne asbestos concentration inside the work area before and after
abatement for samples analyzed by both TEM (p = 0.012) and PCM (p = <0.001).
Mean asbestos concentrations increased significantly after abatement for samples
analyzed Dy both techniques (Table 8). The increase may be attributable to the
difference in sampling conditions (i.e., static conditions in the preabatement phase
versus aggressive conditions in the postabatement phase.
TEM Clearance Comparison
The clearance comparison made with the Student's t-test indicated that the
mean asbestos concentration inside the work area after the abatement (0.0023
f/cm3) was not statistically greater than the mean asbestos concentration outside the
work area after abatement (0.0028 f/cm3) (t = -0.43, p = 0.659). This same
comparison made using the Z-test also showed that the concentrations inside the
work area were not significantly greater than the concentrations outside the work
area (Z « -0.41, p = 0.659). Therefore Site 3 passed both the Purple Book and
AHERA TEM clearance test.
Comparison of the postabatement asbestos concentrations inside the work area
with those outside the building also show no statistically significant differences with
either the t-test (t« 1.58, p = 0.077) or the Z-test (Z « 1.22, p => 0.111). Thus,
comparison of postabatement concentrations inside the work area with those outside
the building also result in Site 3 passing both Purple Book and AHERA clearance
criteria.
PCM Clearance Comparison
One of the postabatement samples collected inside the work area showed fiber
concentrations of 0.014 f/cm3 versus the clearance criterion of 0.01 f/cm3 (Table 8).
Therefore, Site 3 failed the PCM clearance criteria.
As discussed under Site 1, the difference in the conclusion reached by the two
analytical protocols confirms a serious limitation of PCM analysis (i.e., PCM cannot
distinguish asbestos from nonasbestos fibers). Figure -!6 suggests that the fibers
counted by PCM were nonasbestos forms. Therefore, this site's failure to pass the
abatement clearance criteria, in terms of the presence of airborne asbestos, is
believed to be erroneous.
41
-------
10
to
j5 to.o
UJ
o 5.6
- 3.2
£ '-8
§ i. 0
on
o
0.56-
0.32 -
0. 18 -
0. I -
PCM Method 7400
0.01 0.032 O.I 0.32 t.O 3.2 10.0
STRUCTURE DIAMETER, MICROMETERS
PPU UFTHOn 7dfin
-»• + 1 CHRYSOTILE M
A A t AMPHIBOLE B
8 8 1 AMBIGUOUS F
C C 1 AMBIGUOUS C
W W J NON ASBESTOS M
* * * t CHRYSOTILE F
» a a t CHRYSOTILE C
0001 AMPHIBOLE M
o o o \ AMBIGUOUS B
N N N 1 NON ASBESTOS F
y Y Y 1 NON ASBESTOS C
o o o 1 CHRYSOTILE B
x x x 1 AMPHIBOLE f
Q a a 1 AMPHIBOLE C
2221 AMBIQUOUS M
V V V 1 NON ASBESTOS. B
Figure 16. Pjot of structure lenglh ond diometer for postobptement
oir samples coJ'tected inside the work oreo for site 3.
-------
Plot of Mean Asbestos Concentrations Based on Minimum Fiber Length
Figures 17 and 18 graphically present mean asbestos fiber concentrations of
the samples analyzed by TEM based on minimum fiber length for samples outside
the work area and samples inside the work area, respectively. Because PCM
analysis counts only particles >5 urn in length, these plots show that portion of the
total asbestos fiber concentration consisting of particles <5 urn in length.
Comparison of Concentrations Inside. the, Work Are, a With Ambient Air
Concentrations After Abatement
The Wilcoxon rank sum test revealed that the mean asbestos concentration
inside the work area after abatement was significantly greater than the mean ambient
air asbestos concentration for TEM-analyzed samples (p = 0.025), but not for PCM-
analyzed samples (p = 0.918). The mean asbestos concentration for TEM analyzed
samples inside the work area after abatement was approximately twice as large as the
mean ambient air concentration in TEM-analyzed samples after abatement (Table 8).
Comparison of Concentrations in Samples Collected on 0.4 ^im Pore Size
Polcarbonate and 0.8 im Pore Size Mixed Cellulose Ester Membrane Filters
The asbestos concentrations measured on 0.8 urn pore size mixed cellulose
ester filters are plotted against the corresponding measurements made on 0.4 pm
pore size polycarbonate filters (Figure 19). The asbestos concentrations are higher
on 0.4 urn pore size polycarbonate filters than on the 0.8 urn pore size mixed
cellulose ester filters.
The Wilcoxon signed rank test revealed a significant difference in mean
asbestos concentrations between the two filter types (p » 0.0001 ). The mean
asbestos concentration of samples collected on 0.4 (im pore size polycarbonate
filters was 0.0058 f/cm3 greater than the mean asbestos concentration of samples
collected on 0.8 ^im pore size mixed cellulose ester filters.
Asbestos Concentrations in Exhaust Duct Discharge Air From a Negative Air
Filtration Unit
Rgure 20 graphically presents the mean asbestos concentrations of the sample
analyzed by TEM based on cumulative fiber length for five mixed cellulose ester and
six polycarbonate filter samples obtained in the exhaust duct from a negative air
filtration unit at Site 3. Overall, the mean asbestos concentrations were 0.0010 f/cm3
on mixed cellulose ester filters and 0.0029 f/cm3 on polycarbonate filters. A higher
mean concentration on the polycarbonate filters is consistent with the concentration
comparison presented above for these two filter types.
43
-------
o
o
o:
»—
z
UJ
O
Z
O
O
0.0 0.5
2.5 3.0 3.5 4.0 4.5 5.0
MINIMUM LENGTH OF FIBER. MICROMETERS
BOB PRE
DURING
POST
5.5
Figure 17. Plot of meon osbestos concent rot ions bosed on minimum fjber
length for samples collected outside the work area (perimeter)
for site 3.
-------
0.0026
0.0024
0.0022
^ 0.0020
**". 0.0018-
o 0.0016-
< 0.0014-
a:
z 0.0012-
^ 0.0010-
*- o
01 ° 0.0008
2 o.'oooe-
2 0.0004-
0.0002
0.0000
0
•l ft _.-,-. ^^^
-0.0026
-0.0024
-0.0022
-0.0020
•0.0018
-0.0016
-0.0014
•0.0012
•0.0010
•0.0008
0.0006
0.0004
-0.0002
^0.0000
l'4'l'J't'I'l'l'l'l'l'l
.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5
MINIMUM LENGTH OF fIBER. MICROMETERS
ODD PRE A-A-A POST
figure 18. Plot of meon osbestos concentrations based on minimum
fiber length for samples collected inside the work area
for si te 3.
-------
o>
(This line represents a 1:1
correspondence between filters)
* Represents 19 pairs where no
fibers were detected.
-10 -9 -8 -7 --6 -5 -4 . -3 -2 -1
POLYCARBONATE LOG CONCENTRATION. F/CC
Figure 19. Relationship between average airborne asbestos
concentrations measured on 0.8 pore-size mixed
cellulose ester and 0.4 pore-size polycarbonate
merabr one (i U er s.
-------
o
o
o
t—
<:
ca
»—
z:
UJ
o
z
o
o
.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5
MINIMUM LENGTH Of fIBER. MICROMETERS
DOB CELLULOSE ESTER
POLYCARBONATE
figure 20. Plot of raeon osbestos concent rot ions bosed on minimum
fiber length for samples collected inside the exhaust
duct from o negative air filtration system at site 3.
-------
REFERENCES
1. U.S. Environmental Protection Agency. Asbestos-Containing Materials in
School Buildings: A Guidance Document, Part 1. Office of Toxic Substances,
Washington, D.C. 20460. March 1979.
2. U.S. Environmental Protection Agency. Guidance for Controlling Friable
Asbestos-Containing Materials in Buildings. Office of Toxic Substances,
Washington, D.C. EPA 560/5-83-002. March 1983.
3. U.S. Environmental Protection Agency. Guidance for Controlling Asbestos-
Containing Materials in Buildings. EPA 560/5-85-024. June 1985.
4. U.S. Environmental Protection Agency. Friable Asbestos-Containing Materials
in Schools: Identification and Modifications, Washington, D.C. Office of Toxic
Substances. EPA 40 CFR Part 763. 1982.
5. U.S. Environmental Protection Agency. Asbestos in Buildings: Simplified
Sampling Scheme for Friable Surfacing Materials. Office of Toxic Substances,
Washington, D.C. EPA 560/5-85-030a. 1985a.
6. PEI Associates, Inc. Assessment of Asbestos Removal Under Latest Guidance
Conditions Quality Assurance Project Plan. U.S. Environmental Protection
Agency, Contract No. 68-03-3197. June 1986.
7. NIOSH. Method 7400, National Institute for Occupational Safety and Health.
NIOSH Manual of Analytical Methods. Third Edition, Volume 2, March, 1987
Revision. Cincinnati, Ohio. U.S. Department of Health and Human Services.
DHHS (NIOSH) Publication No. 84-100. 1987.
8. Yamate, G, S. C. Agarwal, and R. D. Gibbons. Methodology for the
Measurement of Airborne Asbestos by Electron Microscopy. Draft Report.
Office of Toxic Substances, Washington, D.C. EPA Contract No. 68-02-3266.
1984.
9. SAS Institute Inc. SAS User's Guide: Basics, Version 5 Edition. SAS Institute
Inc., Gary North Carolina. 1985. pp.1187.
10. Hollander, M. and D.A. Wolfe. Nonparametric Statistical Methods. John Wiley
and Sons, New York. 1973. pp. 68, 115, and 129.
48
-------
11. U.S. Environmental Protection Agency. Assessment of Assay Methods for
Evaluating Asbestos Abatement Technology at the Corvallis Environmental
Research Laboratory. Water Engineering Research Laboratory, Cincinnati,
Ohio, EPA 600/S2-86/070. January 1987.
12. U.S. Environmental Protection Agency. Evaluation of Asbestos Abatement
Techniques. Phase 3: Removal. Washington, D.C. Office of Toxic Substances.
U.S. Environmental Protection Agency, Draft Final Report, January 6, 1988.
49
-------
APPENDIX A
AIRBORNE TOTAL FIBER CONCENTRATIONS BEFORE, DURING,
AND AFTER ABATEMENT FOR SAMPLES ANALYZED BY
TRANSMISSION ELECTRON MICROSCOPY
The column headings for Appendix A are defined below:
DATE_SAM a Date sampled
SAMP a Sample number
CONC a Asbestos concentration in structures per cubic
centimeter of air sampled
N a Total number of asbestos particles
SENSTVTY a Analytical sensitivity
STRMM2 a Asbestos structures per square millimeter
50
-------
TABLE A-1. SITE 1 PREABATEMENT AIRBORNE ASBESTOS
CONCENTRATIONS (l/cm3) BY TEM
AMBIENT
OATE^SAfl
10/31/86
11/01/86
11/01/86
PERIMETER
DATE.SAR
10/31/86
10/31/86
10/31/86
10/31/86
10/31/86
10/31/86
11/01/86
11/01/86
11/01/86
11/01/86
11/01/86
11/01/86
SAHP
2013
2019
2025
SAflP
200U
2005
2006
2010
2011
2012
2016
2017
2018
2022
2023
2021
cone
0.005080
0.003182
0.004150
CO»C
0.003383
0.00695<4
0.003510
0.009762
0.008101
0.001573
0.003244
0.011U76
0.001732
0.008UU5
0.001433
0.002836
N
3
2
3
I
2
u
2
6
5
1
2
7
1
6
1
2
SKHSTVTT
0.002
0.002
0.001
SEISTTTT
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.001
0.001
0.001
STRHII3
02.1
28.0
42.1
28.0
56.1
28.0
84.2
70.1
11.0
28.0
98.2
14.0
84.2
14.0
28.0
ABATEMENT AREA
DATE.SAH
SAHF
CO»C
10/31/86
10/31/86
10/31/86
10/31/86
10/31/86
10/31/86
11/01/86
11/01/86
11/01/86
11/01/86
FIELD BLANK
DATE_SAfl
10/31/86
11/01/86
11/01/86
2001
2002
2003
2007
2008
2009
2014
2015
2020
2021
SAflP
2026
2027
2028
0.011728
0.003620
0.008459
0.008160
0.014886
0.003225
0.006540
0.019525
0.001396
0.008730
CO*C
•
•
•
7
5
5
5
9
2
4
12
1
6
•
2
•
4
S«»ST»Tt
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.001
0.031
SBHSTfTT
ST8HH2
98.2
70.1
70.1
70.1
126.3
28.0
56.1
168.4
14.0
84.2
STIHN2
28.0
<14.0
56.1
51
-------
TABLE A-2. SITE 1 DURING ABATEMENT AIRBORNE ASBESTOS
CONCENTRATIONS (f/cm3) BY TEM
AMBIENT
DATE_SA« SAHP COIIC
11/18/86 2039 0.007999
11/19/66 2044 O.OOSS68
11/21/86 2079 <0. 001188
11/20/86 2086 <0. 001290
PERIMETER
DATE.SAH SAUP COHC
11/13/86 2029 0.037603
11/13/86 2030 0.0025U1
11/13/86 2031 0.001215
11/13/86 2032 0.007486
11/13/86 2033 0.038808
11/13/86 203U 0.001935
11/18/86 2035 0.005U60
11/18/86 2036 0.002781
11/18/96 2037 0. 005411
11/18/86 2038 0.001<4U2
11/19/86 2040 0.003547
11/19/86 2011 0.02S067
11/18/86 2042 0.001U67
11/19/86 20<43 0.007245
11/19/86 20U5 0.0014897
11/19/06 2046 <0. 001238
11/2H/86 2052 0.012936
11/21/86 2055 0.009483
11/24/86 2056 <0. 001183
11/24/86 2057 0.018719
11/21/86 2064 0.017358
11/24/86 207«l 0.001192
11/21/S6 2078 0.007131
11/21/86 2080 0.008965
11/21/86 2083 0.003568
11/20/86 208ti 0.009163
11/20/87 2090 0.001540
11/20/86 2091 0.013056
11/20/86 2092 0.012445
11/20/86 20<53 O.OOS192
ll.-2<4/86 2095 0.007468
FIELD BLANK
DATE..SAH SAflP COKC
11/18/86 20147
11/20/86 2062
11/20/86 2065
11/19/86 2072
11/21/86 2075
II
4.0
4.5
•
*
N
11.5
2.0
1.0
6.0
29.0
1.0
<4.0
2.0
3.0
1.0
3.0
16.0
1.0
6.0
U.O
*
11.0
8.0
•
16.0
11. 5
1.0
6.0
7.5
3.0
7.0
1.0
10.0
9.5
U.O
5.0
N
1
•
2
2
4
SE»SI»TT
0.002
0.001
0.001
0.001
SEHSTYTI
0.003
0.001
0.001
0.001
0.001
0.002
0.001
0.001
0.002
0.001
0.001
0.002
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.002
0.001
0.001
0.001
0.031
0.001
0.002
0.001
0.001
0.001
0.001
SEM3ITTT
*
•
•
•
•
STRBH2
56.1
63.1
<1U.O
<14.0
STRHH2
161.4
28.0
14.0
84.2
407.1
14.0
112.3
28.0
02.1
14.0
<42.1
22U.6
14.0
84.2
56.1
<14.0
154. 4
112.3
<14.0
224.6
161.4
14.0
84.2
105.2
«2.1
98.2
14.0
140.3
133.3
56.1
70.1
3Tnnn2
14.0
<14.0
28.0
28.0
56.1
52
-------
TABLE A-3. SITE 1 POSTABATEMENT AIRBORNE ASBESTOS
CONCENTRATIONS (f/cm3) BY TEM
AMBIENT
OATE_SAH
12/03/86
12/03/86
12/03/86
12/03/86
PERIMETER
0»T£_SAF1
12/03/86
12/03/86
12/03/86
12/03/86
12/03/86
SAflP
20SO
205U
2089
2094
SAIIP
20U9
2066
2076
2077
2085
cone
0.009836
<0. 001525
0.008017
0.008978
CONC
0.001S7U
0.0126S6
0.004950
0.00757«
0.001709
M
6
•
5
5
N
1.0
7.5
3.0
5.0
1.0
SENSTVTT
0.002
0.002
0.002
0.002
SEMSTtTT
0.002
0.002
0.002
0.002
0.002
5TRHH2
84.2
<1U.O
70.1
70.1
STRHH2
14.0
105.2
42.1
70.1
14.0
ABATEMENT AREA
OATE^SIR SiflP
cone
12/03/86
12/03/86
12/03/86
12/03/86
12/03/86
FIELD BLANK
DATE_SAH
12/03/86
2068
2069
2070
2071
2073
SAflP
2058
0.008260
0.0110UO
0.003517
0.001783
0.003213
cone
.
5
7
2
1
2
N
6
SENSTVTT
0.002
0.002
0.002
0.002
0.002
SEHSTVTY
STRKH2
70.1
98.2
28.0
14.0
28.0
STRHI12
84.2
53
-------
TABLE A-4. SITE 2 PREABATEMENT AIRBORNE ASBESTOS
CONCENTRATIONS (f/cm3) BY TEM
AMBIENT
OAT8_SAfl
OU/03/87
OU/03/87
OU/03/87
OU/03/87
OU/03/87
SAflPLE
2151
21SU
2157
2163
2167
CONC
<0. 001659
<0. 001632
<0. 001702
0.001837
0.003612
N
1
2
SEKSTtTI
0.002
0.002
0.002
0.002
0.002
578(102
<16.0
<16.0
<16.0
16.0
32.0
PERIMETER
OATE_SAI!
OU/03/87
OU/03/87
OU/03/87
OU/03/87
OU/03/87
SAMPLE
21U9
2156
2159
2162
2165
CO!»C
0. 00<4910
<0. 002059
0.003323
<0. 001717
0.006827
II
3
•
2
•
a
SENST»TT
0.002
0.002
0.002
0.002
0.002
STRHH2
U8.0
<16.0
32.0
<16.0
6U.1
ABATEMENT AREA
OATE_SA(1 SAHPLE
CONC
SENSTVTI
FIELD BLANK
DATE_SA!1
OU/03/87
SABPLE
2166
CONC
SEHST»TI
3T8HB2
OM/03/87
OU/03/87
OU/03/87
OU/03/97
OU/03/87
21S2
2160
2161
2163A
2168
<0. 001609
0.168596
<0. 001671
0.013UU6
0.001674
•
05
.
8
1
0.002
O.OOU
0.002
0.002
0.002
<16.0
802.8
<16.0
128.2
16.0
<16.0
54
-------
TABLE A-S. SITE 2 DURING ABATEMENT AIRBORNE ASBESTOS
CONCENTRATIONS (t/cm3) BY TEM
AMBIENT
OATB,SAfl
04/06/87
04/06/87
04/06/97
04/06/87
04/06/37
PERIMETER
DAIE.SAn
OU/03/97
OU/07 '87
OU/06/S7
OU/06/87
04/07/87
OU/06/97
04/06/87
04/07/87
OU/07/J7
04/06/37
Ou/06/87
O'l/OS/37
04/07/37
OU/09/97
Ou/08/87
OU/08/87
OU/08/07
OH/08/87
OU/08/S7
OU/09/8 1
OU/08/87
04/08/87
OU/09/87
OU/07/«7
0'l/08/87
OU/08/87
04/07/87
OU/OS/87
04/09/87
04/08/87
09/08/87
FIELD BLANK
OATE.SAB
04/07/87
04/06/87
0»/08/87
SAMPLE
2298A
2307
2333
2334
2336
SAHPLE
2270
2297
22988
2299
2300
2306
2308
2309
2310
2329
2331
2332
2333
2J7U
2375
2376
2371
2378
2379
2380
2381
23S2
2383
238U
238b
2J86
2387
2368
2389
2390
2393
S«BPLt
2267
2274
219?
co»c
0.001034
<0. 000551
CO. 000572
<0. 000613
0.001226
cone
0.015«>72
0.006121
0.058950
O.OOU759
0.09951"
<0. 000558
0.011790
0.012350
1.01U012
0.000538
0.000623'
0.019655
0.017689
0.021215
0.016553
0.003270
0.027337
0.003453
0.09S269
0.016122
0.033610
0.038957
0.015430
0.013108
0.017865
0.091711
0.228608
0.001169
0.001331
0.045762
O.OU46U
CO«C
.
.
.
1
2
•
2
N
29
1
22
8
39
22
1
12
1
1
31
15
3u
23
5
23
3
40
26
28
37
27
6
17
40
18
1
2
28
10
1
.
.
. •
Se«STTTT
0.001
0.001
0.001
0.001
0.001
SEHSTtTT
0.001
0.006
0.003
0.001
0.003
0.001
0.001
0.012
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.002
0.001
0.001
0.001
0.001
0.002
0.001
0.002
0.013
0.001
0.001
0.002
0.001
S8»ST»TT
.
•
•
STRHH2
32.0
<16.0
<16.0
<16.0
32.0
STI««2
464.7
80.1
762.8
128.2
250.0
<16.0
352. 5
160.2
192.3
16.0
16.0
620.9
240.3
544.0
460.7
80.1
368.5
U8.0
282.0
416.6
448.7
592.9
432.6
160.2
4S4.0
282.0
184.6
16.0
32.0
6«1.0
160.2
STIHH2
<16.0
<16.0
<16.0
55
-------
TABLE A-6. SITE 2 POSTABATEMENT AIRBORNE ASBESTOS
CONCENTRATIONS (f/cm3) BY TEM
PERIMETER
OATE_SAfl
OU/09/87
OU/09/87
OU/09/87
OU/09/87
Ou/09/87
OU/09/87
OU/09/87
SAMPLE
23U4
23US
23U6
2355
2356
236U
2365
COHC
0.298708
0.3U1U01
0.328SS3
0.027676
0.35U70U
0.019832
0.316302
N
29
18
57
1«
18
10
48
SE«ST»TT
0.010
0.019
0.006
0.002
0.020
0.002
0.007
STHI1f!2
323.7
881.6
UU.8
721.3
88U.6
160.2
56U.1
ABATEMENT AREA
DATE_SA.1 ' SAflPLE
COHC
OU/09/87
OU/09/97
OU/09/87
OU/09/87
OU/09/87
FIELD BLANK
DATE_SAfl
OU/09/87
23U7
23S7
2358
2366
2367
SAMPLE
2368
0.173197
0.230291
0.617811
0.266739
0.2S3060
cose
•
17
36
30
13
37
N
^
SEKSTVTY
0.010
0.006
0.021
0.021
0.007
SEHSTtTT
STRHH2
362.1
923.0
807.6
63. 3
976.U
STRHH2
<32.0
56
-------
TABLE A-7. SITE 3 PREABATEMENT AIRBORNE ASBESTOS
CONCENTRATIONS (»/cm3) BY TEM
AMBIENT
DATe_SAH
08/19/87
08/19/87
08/19/87
08/19/87
08/19/87
08/19/87
PERIMETER
0»TE_SAH
08/19/87
08/19/87
08/19/87
08/19/87
08/19/87
08/19/87
SAflp"
P1494
P1S04
P1505
2429
2440
246S
SAnP
P1U85
P1190
P1495
24U1
2442
2452
COMC N
0.001193 1
<0. 001205
<0. 001197
<0. 001193
<0. 001197
<0. 001205
COUC N
<0. 001210
<0. 001205
<0. 001205
<0. 001205 .
0.002419 2
<0.00120S
SE»ST»TT
0.001
0.001
0.001
0.001
0.001
0.001
SEHSTfTT
0.001
0.001
0.001
0.001
0.001
0.001
STRHH2
8.8
<8.8
<8.8
<8.8
<8.8
<8.8
5Tlnn2
<8.6
-------
TABLE A-8. SITE 3 DURING ABATEMENT AIRBORNE ASBESTOS
CONCENTRATIONS (f/cm3) BY TEM
NEGATIVE AIR EXHAUST
om.sAii
09/01/87
09/02/87
09/04/87
09/04/87
09/08/87
09/08/87
09/04/87
09/03/87
09/04/87
09/01/87
09/02/87
PERIMETER
DATE_S»n
09/01/87
09/01/87
09/01/87
09/01/87
08/31/87
09/01/87
08/31/87
08/31/87
08/20/87
08/20/87
08/20X87
08/31/87
08/31/87
09/01/87
09/04/87
08/20/87
09/01/87
08/20/87
09/01/87
08/20/87
08/20/87
08/20/87
09/01/87
09/01/87
08/20/87
09/03/87
09/03/8V
09/04/87
09/03/87
09/04/87
09/04/87
09/08/87
09/08/87
09/08/87
09/08/87
(continued)
S»«P
P1555
P1571
P16S3
P1660
P1669
2405
2521
2531
2532
2548
2553
s*np
P14S7
P1497
P1498
. P1S01
P1S08
P1512
P1524
P1549
P1S50
P1SS1
P1SS2
P1554
P1SS8
P1569
P1570
P1573
P1S7U
P1577
P1579
P1580
P1S81
P1S86
P1590
P1S92
P1595
P1652
P1655
P16S6
P1658
P1661
P1662
P1670
P1671
P1672
P1674
cone
0.000376
<0. 001249
0.004061
<0. 001337
<0. 001462
0.002924
<0. 001341
0.006867
0.004061
<0. 000376
0.003746
COMC
<0. 000826
<0. 000822
<0.0008S7
<0. 000912
<0. 00083$
0.000794
0.001512
<0. 000743
<0. 001416
<0. 001416
<0. 000236
0.000897
<0. 000994
0.001157
<0. 000876
<0. 001662
<0. 001030
<0. 001416
<0. 001100
<0. 001416
<0. 001416
<0. 000236
<0. 001149
<0. 001233
<0. 000276
<0. 001185
0.002215
<0. 000823
0.001028
<0. 001068
<0. 001196
<0. 001130
<0. 001040
•
<0. 001028
II SCISTTTT
1 0.000
0.001
10 0.000
0.001
0.001
2 0.001
0.001
S 0.001
10 0.000
0.000
, 3 0.001
N SE»ST»TT
0.001
0.001
0.001
0.001
0.001
1 0.001
2 0.001
0.001
0.001
0.001
0.000
1 0.001
0.001
1 0.001
0.001
0.002
0.001
0.001
0.001
0.001
0.001
0.000
0.001
0.001
. 0.000
0.001
2 0.001
0.001
1 0.001
0.001
0.001
0.001
0.001
2
0.001
STIHH2
8. 6
<8.6
86.2
<8.8
<8.8
17.6
<8.8
14.1
88.2
<8.8
26.4
STRIinZ
<8.8
<8.8
<8.8
<8.8
<8.8
8.8
17.6
<6.8
<8.3
<8.8
<8.3
8.8
<8.8
8.8
<8.8
<8.8
<8.«
<8.8
<8.8
<8.8
<8.8
<8.8
<8.8
-------
TABLE A-8 (continued)
PERIMETER
OATE.SAN
09/09/87
09/09/87
09/09/87
09/09/87
09/10/87
09/10/87
09/09/87
09/10/87
09/09/87
09/09/87
09/10/87
09/10/87
09/11/87
09/09/87
09/10/87
09/11/97
09/10/87
09/11/87
09/10/87
09/11/87
09/11/87
09/OU/87
09/10/97
09/1J/87
09/10/87
08/20/87
09/10/97
08/20/87
09/09/87
09/11/87
08/20/87
09/11/87
09/11/87
09/11/97
09/11/87
09/09/87
09/09/87
09/10/87
09/13/87
09/09/87
09/09/87
09/08/87
09/03/87
09/03/37
09/08/87
09/03/87
09/02/87
09/014/87
09/01/87
09/CI/87
09/01/87
09/01/87
SAHP
P167S
P1676
P1677
P1678
P1681
P1682
P1686
P1687
P1689
P1690
P1693
P169«
P1696
P1697
P1696
P1699
P170U
P1706
P1707
P1709
P1715
2«2<4
2»3U
2<438
2«<45
2«U7
2<463
2 "46 7
2069
2«76
2<477
2180
2«82
2U83
2tt90
2«93
2195
2H97
2"498
250J
2505
2510
2511
2512
2520
252.2
2523
2521
2520
2526
2527
2528
cone
<0. 001079
0.0076UX
0.002130
<0. 001098
0.002081
0.00166(4
<0.0022«9
0.000951
<0. 003582
<0. 002179
0.003791
<0. 000977
0.008300
0.019609
<0. 002179
0.133702
O.OOU358
0.001787
<0. 002179
0.071121
o.miiai
<0.0008U2
0.03126U
0.000803 '
0.013311
0.000236
0.067297
<0. 00027U
0.019167
0.022826
< 0.00027 6
0.095536
0.030372
0.102366
0.12207U
0.006585
<0. 000981
C0.0010UO
<0. 000808
0.0076<4l
0.003236
0.003390
<0. 001185
. O.OOUU30
<0.0010<40
O.OOU353
0.00103U
0.001199
0.0016S2
0.023813
0.006386
0.005753
«
•
7
2
•
2
2
•
1
•
.
4
* •
a
9
•
12t)
2
2
.
67
133
,
32
1
1«
1
71
.
18
22
.
90
3«
98
115
6
•
•
.
7
3
3
•
14
.
14
1
1
2
30
' 7
7
SdSTVff
0.001
0.001
0.001
0.001
0.001
0.001
0.002
0.001
O.OOU
0.002
0.001
0.001
0.001
0.002
0.002
0.001
0.002
0.001
0.002
0.001
0.001
0.001
0.001
0.001
0.001
0.000
O.C01
0.000
0.001
0.001
0.000
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
STHRH2
-------
TABLE A-8 (continued)
PERIMETER
SAHP
cone
StMSTVTT
08/31/87
09/08/87
09/02/87
09/02/87
09/04/87
OV/04/87
09/01/87
09/08/87
09/03/87
09/02/87
09/04/87
09/03/87
09/02/87
09/08/87
08/31/87
08/31/87
08/31/87
03/31/87
FIELD BLANK
DATE_SAH
08/31/87
09/02/87
09/01/87
08/20/87
08/20/87
09/04/87
09/10/87
09/11/87
09/13/87
08/20/87
08/20/87
09/11/87
09/10/87
09/02/87
09/01/87
09/04/87
08/31/87
09/03/87
2529
2530
2533
2534
2536
2537
2538
2540
2542
2544
2545
2546
2547
2550
2554
2555
2556
2557
SAilP
P1566
P1583
P1589
P1596
' P1597
P1663
P1685
P1717
2455
2459
2473
2488
2496
2535
2539
2541
25U9
2552
0.003587
0.004536
<0. 001157
0.002297
0.003205
0.000876
0.006001
0.001028
0.016455
0.004933
0.000023
0.006509
0.002199
0.001170
0.000835
0.002268
<0. 000994
<0. 000743
CO!tC
f
,
,
„
.
.
.
.
m
.
,
.
.
f
.
,
m
.
<|
a
.
2
3
1
7
1
16
4
I
6
2
1
1
3
.
-
N
9
t
.
.
,
.
• .
.
.
.
.
,
2
^
',
,
a
2
0.001
0.001
0.001
0.001
0.001
o.oox
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
S8NSTVTT
*
^
•
.
.
,
.
.
a
,
.
.
^
w
.
,
.
.
STBnn2
35.3
35. 3
<8.8
. 17.6
26.a
8.8
61.7
8.8
1U1.2
35.3
8.a
52.9
17.6
8.8
8.8
26.4
<8.8
<8.8
STdnn2
<8.8
<8.8
<8.8
<8.8
<8.8
<8.8
<8.8
<8.8
<8.8
<8.8
<8.8
<8.8
17.6
<8.8
<8.8
<8.8
<8.8
17.6
P1000 series are mixed cellulose ester filters; 2000 series are
polycarbonate filters.
60
-------
TABLE A-9. SHE 3 POSTABATEMENT AIRBORNE ASBESTOS
CONCENTRATIONS (t/crr>3) BY TEM
AMBIENT
S««P
CO«C
STtflfQ
09/10/87
09/14/87
09/14/87
09/14/87
09/14/87
09/14/87
P1713
P1716
P1722
2613
2636
2637
<0. 001019
<0. 001082
<0. 000957
<0. 001019
<0. 000957
<0. 001082
—
.
.
.
.
.
0.001
0.001
0.001
0.001
0.001
0.001
-------
APPENDIX B
AIRBORNE ASBESTOS CONCENTRATIONS BEFORE, DURING,
AND AFTER ABATEMENT FOR SAMPLES ANALYZED BY
PHASE CONTRAST MICROSCOPY
62
-------
TABLE B-1. SlfE 1 PREABATEMENT AIRBORNE ASBESTOS
CONCENTRATIONS (l/cm3) BY PCM
DATS
10/31/86
11/01/86
11/01/86
10/31/86
10/31/86
10/31/86
10/31/86
10/31/86
10/31/86
11/01/86
11/01/86
11/01/86
11/01/86
11/01/86
11/01/86
10/31/86
10/31/86
10/31/86
10/31/86
10/31/86
10/31/86
11/01/86
11/01/86
11/01/86
11/01/86
10/31/86
11/01/86
11/01/86
SAMPLE
NUMBER
CONCENTRATION
AMBIENT
1013
1019
1025
0.001
0.001
<0.001
PERIMETER
1004
1005
1006
1010
1011
1012
1016
1017
1018
1023
1022
1024
0.001
0.002
0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
ABATEMENT AREA
1001
1002
1003
1007
1008
1009
1014
1015
1021
1020
FIELD BLANK
1026
1027
1028
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
1.5 f/100 fleldo
0 f/100 fieldB
1.0 f/100 fields
63
-------
TABLE B-2. SITE 1 DURING ABATEMENT AIRBORNE ASBESTOS
CONCENTRATIONS (f/cm?) BY PCM
DATS
11/18/86
11/19/86
18/20/86
11/21/86
11/13/86
11/13/86
11/13/86
11/13/86
11/13/86
11/13/86
11/18/86
11/18/8$
11/18/86
11/18/86
11/18/86
11/19/86
11/19/86
11/19/86
11/19/86
11/19/86
11/20/86
11/20/86
11/20/86
11/20/86
11/20/86
11/21/86
11/21/86
11/21/86
11/21/86
11/21/86
11/24/86
11/24/86
11/24/86
11/24/86
11/24/86
11/19/86
11/20/86
11/21/86
11/24/86
SAMPLE
NUMBER CONCENTRATION
AMBIENT
1039
1041
1072
1058
PERIMETER
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1042
1049
1040
1050
1051
1052
1066
1068
1070
1074
1076
1056
1057
1055
1059
1060
1079
1062
1086
1054
1064
FIELD BLANK
1063
1078
1061
1065
0.002
0.001
<0.001
<0.001 .
0:003
0.006
0.002
0.009 .
0.002
0. 006
0.003
0.002
0.001
0.001
0.002
<0.001
<0.001
0.001
0.002
0.001
0.003
0.001
0.002
0.002
<0.001
0.003
0.001
0.002
0.002
0.003
0.002
0.001
0.001
0.004
0.003
0 f/100 fields
0 f/100 fields
1.0 f/100 fields
0.5 f/100 fields
64
-------
TABLE 8-3. SITE 1 PQSTA8ATEMENT AIRBORNE ASBESTOS
CONCENTRATIONS (l/cm3) BY PCM
DATE
12/03/86
12/03/86
12/03/86
12/03/86
12/03/86
12/03/86
12/03/86
12/03/86
12/03/86
12/03/36
12/03/86
12/03/86
12/03/86
12/03/86
12/03/86
12/03/87
SAMPLE
NUMBER
CONCENTRATION
AMBIENT
1093
1092
1105
1238
1244
PERIMETER
1237
1241
1239
1243
1232
<0.001
<0.001
0.001
<0.001
<0.001
0.002
0.002
0.004
0.002
0.001
ABATEMENT AREA
1100
1240
1234
1094
1242
FIELD BLANK
1084
0.002
0.002
0.002
0.001
<0.001
1.5 f/100 fields
65
-------
TABLE 8-4. SITE 2 PREABATEMENT AIRBORNE ASBESTOS
CONCENTRATIONS (l/cm3j BY PCM
DATE
1/21/87
1/21/87
1/21/87
1/21/87
1/21/87
1/21/87
1/21/87
1/21/87
1/21/87
1/21/87
1/21/87
1/21/87
1/21/87
1/21/87
1/21/87
1/21/87
SAMPLE
NUMBER
CONCENTRATION
AMBIENT
1276
1290
1270
1291
1269
0.001
0.001
0.001
0.002
0.001
PERIMETER
1281
1 1274
1288
1287
1273
ABATEHENT AREA
1282
1272
1289
1259
1257
FIELD BLANK
1266
0.001
0.002
0.001
0.001
0.002
0.001
0.001
0.001
0.002
0.001
0 f/100 fields
66
-------
TABLE B-5. SITE 2 DURING ABATEMENT AIRBORNE ASBESTOS
CONCENTRATIONS (f/cm3) BY PCM
DATE
4/6/87
4/6/87
4/6/87
4/6/87
4/6/87
4/6/87
4/6/87
4/6/87
4/6/87
4/6/87
4/6/87
4/6/87
4/6/87
4/7/87
4/7/87
4/7/87
4/7/87
4/7/87
4/7/87
4/7/87
4/7/87
4/7/87
4/7/87
4/7/87
4/8/87
4/8/87
4/8/87
4/8/87
4/8/87
4/8/87
4/8/87
4/8/87
4/9/87
4/9/87
4/9/87
4/9/87
4/6/87
4/7/87
4/8/87
SAMPLE
NUMBER
AMBIENT
1435
1437
1430
1432
1431
CONCENTRATION
0.001
0.001
0.001
0.001
0.001
PERIMETER
1443
1444
1445
1434
1453
1436
1433
1391
1442
1439
1448
1429
1440
1454
1451
1399
1471
1458
1464
1476
1474
1461
1438
1473
1452
1441
1450
1470
1477
1469
1475
1447
1463
1446
0.001
0.001
0.001 '
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.005
0.004
0.007
0.001
0.001
0.001
0.001
0.001
0.002
0.003
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
0.001
FIELD BLANKS
0 f/100 fields
0 f/100 fields
0 f/100 fields
67
-------
TABLE B-6. SITE 2 POSTABATEMENT AIRBORNE ASBESTOS
CONCENTRATIONS (l/cm3) BY PCM
SAMPLE
DATS NOHBER CONCENTRATION
PERIMETER
4/9/87 1462 0.002
4/9/87 1468 0.001
4/9/87 1466 0.003
4/9/87 1449 0.003
4/9/87 1455 0.008
4/9/87 1457 0.001
4/9/87 1390 0.001
ABATEMENT AREA
4/9/87 1501 0.002
4/9/87 1502 0.002
4/9/87 1504 . 0.001
4/9/87 1503 0.003
4/9/87 1459 0.004
FIELD BLANK
4/9/87 1456 0 f/100 fields
68
-------
TABUS 8-7. SITE 3 PREABATEMENT AIRBORNE ASBESTOS
CONCENTRATIONS (f/cm3) BY PCM
DATE
7/14/87
7/14/87
7/14/67
7/14/87
7/14/87
7/14/87
8
7/14/87
7/14/87
7/14/87
7/14/87
7/14/87
7/14/87
7/14/87
7/14/87
7/14/87
7/14/87
SAMPLE
NUMBER
CONCENTRATION
AflBIENT
P1504
P1505
P1494
PEBIMETER
0.001
0.004
0.001
PI 490 0.003
P1495 0.004
P1485 0.005
ABATEMENT AREA
P1478
P1489
P1488
P1486
P1480
P1481
P1479
P1491
FIELD BLANK
P1500
P1506
0.001
0.002
0.001
0.003
0.002
0.004
0.001
0.002
1 J/100 llcido
0 f/100
69
-------
TABLE 8-8. SITE 3 DURING ABATEMENT AIRBORNE ASBESTOS
CONCENTRATIONS (f/cm3) BY PCM
DATB
8/20/87
8/20/87
8/20/87
8/20/87
8/20/07
C/20/87
8/20/87
8/20/87
8/20/87
8/31/87
8/31/87
8/31/87
8/31/87
8/31/87
9/01/87
9/01/87
9/01/87
9/01/87
9/01/87
9/02/87
9/02/87
9/02/87
9/02/87
9/02/87
9/03/87
9/03/87
9/03/87
9/03/87
9/03/87
9/04/87
9/04/87
9/04/87
9/09/87
9/09/87
9/09/87
9/09/87
9/09/87
9/08/87
9/08/87
9/08/87
9/08/87
9/08/87
9/09/87
9/09/87
9/09/87
9/09/87
9/09/87
SAMPLE
NUMBER
CONCENTRATION
PERIMETER
P1595
P1572
P1586
P1577
P1551
P1581
P1573
PliSO
P1580
P1549
P15J.8
P1524
P1554
P1508
P1512
P1497
P1487
P1498
P1501
P1574
P1592
P1579
P1590
P1569
P265S,
P1652
P1658
P1654
P1656
P1667
P1661
P1662
P1677
P1678
P1675
P1680
P1676
P1671
P1668
P1674
P1670
P1683
P1686
P1689
P1688
P1690
P1697
0.008
0.003
0.009
0.006
0.004
0.007
0.006
0.010
0.009
0.006
0.013
0.047
0.027
,0.01?
C.028
0.001
0.001
0.004
0.004
0.005
0.003
0.013
0.014
0. 004
0.011
0.006
0.028
0.007
0.002
0.001
0.005
0.007
0.024
0.008
0.004
0.001
0.002
0.006
0.002
O.C03
0.003
0.017
0.009
0.010
0.003
0.001
0.046
70
-------
TABLE B-8 (continued)
DATE
9/10/b7
9/10/87
9/10/8V
9/10/87
9/10/87
9/10/87
9/10/87
9/10/87
9/11/87
9/11/87
9/11/87
9/11/87
9/11/87
9/1.3/87
8/20/87
8/20/87
8/31/87
9/01/87
9/02/87
9/03/87
9/03/87
9/09/87
9/10/87
9/11/87
9/13/87
SAMPLE
NUMBER
CONCENTRATION
PERIMETER
P1693
P1694
P1667
P1682
P1681
P1707
P1704
P1698
P1715
P1709
P1699
P1706
P1696
P1679
FIELD
P1597
P1S96
P1666
P1089
P1588
P1560
P1663
P1672
P1685
P1717
P1570
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
0,
0.
c
BLANK
1
0
1
0
1
0
2
3
1
4
052
015
003
001
,001
001
.006
.001
061
026
,026
,002
,001
.002
.0 f/100
0 f/100
.5 f/100
.£ f/100
.5 f/100
.5 f/100
.5 f/100
.5 f/100
.0 f/100
.0 f/100
.5 f/100
fields
fields
fields
fields
fields
fields
fields
fields
fields
fields
fields
71
-------
TABLE B-9. SITE 3 POSTABATEMENT AIRBORNE ASBESTOS
CONCENTRATIONS (l/cm3) BY PCM
DATE .
9/14/87
9/14/87
9/14/87
9/14/87
9/14/87
9/14/87
9/14/87
9/14/87
9/14/87
9/14/87
9/14/87
9/14/87
9/14/87
9/14/87
9/14/87
9/14/87
SAMPLE
NUMBER
CONCENTRATION
AMBIENT
P1718
P1722
P1713
0.012
0.011
0.009
PERIMETER
P1723
P1692
P1714
P1695
P1720
0.006
0.015
0.014
0.001
0.001
ABATEMENT AREA
P1721
P1702
P1724
P1710
P1708
P1719
P1711
0.008
0.006
0.006
0.005
0.010
0.007
0.014
FIELD BLANK
P1705
0 f/100 fields
72
-------
APPENDIX C
PAIRED SAMPLES COLLECTED ON 0.4 urn PORE SIZE
POLYCARBONATE AND 0.8 urn PORE SIZE MIXED
CELLULOSE ESTER MEMBRANE FILTERS
73
-------
TABLE C-1. PAIRED SAMPLES COLLECTED ON 0.4 urn PORE SIZE
POLYCARBONATE AND 0.8 urn PORE SIZE MIXED
CELLULOSE ESTER MEMBRANE FILTERS
Polycarbonate *
2429
2465
2440
2442
2452
2441
2444
2443
2425
2428
2501
2451
2460
2456
2548
2553
2532
2521
2405
2613
2637
2636
2602
2612
2603
2611
2627
2621
2619
2525
2528
2538
2527
2554
2526
2555
2557
Mixed cellulose ester*
P1494
P1504
P1505
P1485
P1490
P1495
P1478
P1479
P1480
P1481
P1486
P1488
P1489
P1491
P1555
P1571
P1653
P1660
P1669
P1713
P1718
P1722
P1701
P1702
P1708
P1711
P1719
P1721
P1724
P1487
P1497
P1498
P1501
P1508
P1512
P1524
P1549
(continued)
74
-------
TABLE C-1 (continued)
Polycarbonate * Mixed cellulose ester*
2529
2556
2533
2537
2523
2547
2447
2534
2544
2477
2511
2512
2545
2542
2536
2524
2510
2520
2540
2505
2503
2469
2493
2497
2445
2463
2434
2476
2483
2482
2490
2480
P1554
P1558
P1569
P1570
P1574
P1579
P1586
P1590
P1592
P1595
P1652
P1655
P1656
P1658
P1661
P1662
P1670
P1671
P1674
P1675
P1676
P1677
P1678
P1681
P1687
P1693
P1694 _
P1696
P1699
P1706
P1709
P1715
* See Tables A-7, A-8, and A-9 for the corresponding sample concentrations.
75
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