Passive/Diffusive Samplers for Pesticides
in Residential Indoor Air
Robert G. Lewis
U.S. Environmental Protection Agency
MD-44, Research Triangle Park, NC 27711, USA
Tel. 919-541-3065
Fax 919-541-3527
e-mail lewis.bob-dr@epa.gov
C. R. Fortune, F. T. Blanchard, and W. D. Ellenson
ManTech Environmental Technology, Inc.,
Research Triangle Park, NC 27709, USA
Pesticides applied indoors vaporize from treated surfaces (e.g., carpets and baseboards)
resulting in elevated air concentrations that may persist for long periods after applications.
Estimating long-term respiratory exposures to pesticide vapors in residential indoor
environments using active (pump-based) sampling systems has been costly and
burdensome on occupants. Diffusion-controlled passive sampling devices (PSDs), which
do not require a noisy pump and can be situated unobtrusively within the home, would
offer distinct advantages. The U.S. EPA is investigating the applicability of diffusive
PSDs, semipermeable membrane devices (SPMDs), solid-phase microextraction (SPME),
and other gas-sorbent partitioning samplers for estimating semivolatile organic compound
(SVOC) pesticides in homes. This paper presents the results of the initial evaluations of
two diffusion-controlled PSDs for determination of three pesticides in room air.
Keywords: pesticides, semivolatile, residential indoor, diffusive, gas-sorbent partitioning
1. Introduction
The United States Environmental Protection Agency (EPA) has for two decades been
interested in potential applications of passive sampling devices (PSDs) for estimating the
concentrations of various pollutants in air. During the early 1980s, several commercial PSDs
designed for workplace use were evaluated for determination of volatile organic compounds
(VOCs) in ambient air but were found to be limited by excessive background contamination
and inadequate sensitivity [1], This led to the development of a stainless steel diffusion-
controlled PSD capable of high sensitivity for VOCs through thermal desorption [2], While this
PSD was manufactured during the 1980s and 1990s by Scientific Instrumentation Specialists,
Inc., Moscow, Idaho, it saw little use [3, 4]. A version of the EPA PSD modified to collect
nitrogen oxides also had limited use for indoor and outdoor air monitoring [5]. By the early
1990s, EPA had adopted a simple diffusive sampler for inorganic gases manufactured in Japan
and marketed by Ogawa & Company USA, Pompano Beach, Florida, and Rupprecht &
Patashnick Co., Inc., Albany, New York [6], The Ogawa 3300 passive sampler for ozone,
developed jointly by EPA and Harvard University, has enjoyed widespread use for ambient air
monitoring in the U.S. [7, 8, 9], Until very recently, however, there has been little interest in
passive sampling for organic compounds.
Exposure to pesticides in indoor air has been a concern for many years, especially after a large
study conducted by EPA in the 1980s showed that 85% of the total daily adult exposure to
airborne pesticides was from breathing air inside the home [10]. Indoor residential sampling
can be restricted because of the lack of available space for sampler placement or by
homeowner objections, particularly regarding equipment noise. Therefore, PSDs, which do not
depend on an air pump, would be attractive for estimating respiratory exposures to pesticides
-------
inside occupied homes. Furthermore, unlike active samplers, PSDs may be deployed for days,
weeks, or months to obtain integrated exposure estimates.
Although the current trend in the U.S. is toward the use of nonvolatile or low-volatility
insecticides for residential pest control, most pesticides fall into the semivolatile category
(vapor pressure range 10"2—-10"8 kPa at 25 °C). This is especially true for disinfectants and room
deodorizers. Semivolatile pesticides will be present in air primarily as vapors, which may be
collected by diffusion onto a sorbent or by gas-sorbent partitioning. PSDs based on these
sampling principles may be employed for estimation of respiratory exposures to pesticides
within the home.
2, Materials and Methods
Two diffusive samplers with which the EPA has extensive experience were chosen for initial
evaluation: the thermally desorbable PSD developed by Lewis et al. [2] and the Ogawa 3300
sampler (see Fig. 1). Both PSDs are cylindrical, dual-faced samplers that employ a series of
diffusion plates and screens to control the sampling rate. The EPA PSD is constructed
primarily of stainless steel and measures 3.8 cm o.d. by 1.2 cm (sorbent bed size 3.0 cm by 0.2
cm). The sorbent selected for this work was Amberlite™ XAD-2 resin (Supelpak-2™,
Supelco, Belafonte, Pennsylvania); 0.73 g was used. The 2-cm o.d by 3-cm Ogawa PSD, which
is designed to collect inorganic gases on treated filters by reactive sampling, was modified by
hollowing out the solid body and filling the 1.5-cm by 1,5-em void with 1.21 g of XAD-2. One
of the two Ogawa stainless steel diffusion screens was placed on either end of the sorbent bed,
and the snap-in diffusion caps were replaced to contain the sorbent.
Figure 1, EPA (left) and modified Ogawa passive samplers.
Three insecticides were chosen for evaluation of the PSDs: diazinon (0,0-diethyl
0-[6-methyl-2-(l-methylethyl)-4-pyrimidinyl]phosphorothioate, CAS No. 333-41-5; vapor
pressure = 1.1 x 10"5 kPa at 25 °C), chlorpyrifos (0,0-diethyl-0-(2-isopropyl-6-methyl-
4-pyrimidinyl) phosphorothioate, CAS No. 2921-88-2; vapor pressure = 2.6 x 10~6 kPa), and
permethrin(0,0-diethyl-0-[6-methyl-2-(l-methylethyl)-4-pyrimidmyl]phosphorothioate, CAS
RETAINER
RING
PERFORATED
PLATE
DIFFUSION
CAP
DIFFUSION
SCREEN
DIFFUSION
SCREEN
SORBENT
COMPARTMENT
SORBENT
CARTRIDGE
-------
No. 333-41-5; vapor pressure = 4.5 x 10"8 kPa) [11], The diffusion coefficients at 25 °C for
these compounds were estimated by the method of Fuller et al. [12] to be 0.045, 0.043, and
0.040 cm/s, respectively. (Note: The Fuller method was modified to utilize the molecular
volume increments of Bondi [13]; in cases where volume increments were not available for
specific molecular groups, they were estimated by comparison with values for other similar
groups.) The sampling rate for the EPA PSD, Re?a, was estimated by multiplying the ratio of
the diffusion coefficient of test pesticide to that of chlorobenzene (DCb = 0.075 cm3/s) by the
empirically-determined sampling rate for chlorobenzene (Rqb = 66.8 cm3/min [2]). The
calculated sampling rates for diazinon, chlorpyrifos, and permethrin were 39.6, 37.8, and 35.2
cm3/min, respectively. The sampling rate for the Ogawa PSD was calculated from Fick's first
law of diffusion (DCp x A/L) to be 6.2, 5.9, and 5.2 cm3/min for diazinon, chlorpyrifos, and
permethrin, respectively. These values are in approximate agreement with the values derived
by multiplying the ratio of the known sampling rate of the Ogawa PSD for N02 (21 cm3/min)
to that of the EPA PSD (154 cm3/min) by Re? a-
The performance of the PSDs was evaluated in a 30-m3 (2.2-m W by 5.9-m L by 2.4-m H)
room (mobile office) with smooth composite wall paneling, vinyl flooring, and painted gypsum
board ceiling. Heating and air conditioning were provided by a 12,100 kj heat pump operating
on 100% recycled air. All cracks and crevices except the door and the windows were sealed.
Exposures were performed in the dark (except when retrieving samples). Continuous
temperature, humidity, and air velocity were monitored with a Davis Weather Monitor II
(Davis Instruments Corp., Hayward, California). The PSDs were deployed at a height of 1.8 m
above the floor by suspending them from wires, each PSD separated by at least 20 cm. The
EPA PSDs were held in a metal protective cage with openings covered with perforated plates
containing 3-mm openings (no significant effect on sampling rate) and O-ring-sealed metal
caps for closure before and after sampling [5]. The Ogawa PSD was held in a plastic mounting
bracket. Three active samplers, with inlets 1.8-m above the floor and situated 117 cm apart,
were evenly placed between the PSDs to determine reference air concentrations of the study
pesticides. The active samplers sampled air at a rate of 1.2 L/min through a 2.5-cm quartz-fiber
filter followed by a 2.2-cm by 7.6-cm polyurethane (PUF) vapor trap [14] and were operated
continuously for 3-d intervals. The emitter source was a cut-pile nylon carpet, 1.8 m by 4.2 m,
placed on the floor and uniformly broadcast-sprayed with aqueous emulsifiable concentrate
pesticide formulations made up from Dursban™ L.O. (Dow Elanco, Indianapolis, Indiana),
41.5% (w/w) chlorpyrifos; Diazinon 4E (Bonide Products, Inc., Yorkville, New York), 47.5%
(w/w) diazinon; and Spectracide Pro™ (Spectrum Group Division of United Industries Corp.,
St. Louis, Missouri), 10.0% (w/w) permethrin.
All samplers were prepared in a clean room free of pesticide contamination. Prior to exposure,
the assembled samplers were enclosed in glass jars with PTFE-lined lids sealed with PTFE
tape. After exposure, the PSDs were returned to their respective containers and kept at -80°C
until extracted. The jars were allowed to equilibrate to room temperature for 2 h before
opening. Once opened, PSDs were handled with tweezers or nitrile-gloved hands and received
only brief exposures to laboratory air. The EPA PSD was removed from its protective cage,
one sampling face was spiked with 400 (iL of a 2.0-ng/jiL standard of p-terphenyl-di4 in n-
hexane (surrogate recovery standard), and the intact device was quickly placed in a 500-mL
Soxhlet extractor and immediately covered with the extraction solvent. The Ogawa PSD was
removed from its mounting bracket, wiped with hexane (since its outer surfaces were exposed),
spiked with the recovery standard, placed in a 250-mL extractor, and covered with solvent. The
filter and PUF trap were removed from the active sampler cartridge and likewise placed in a
250-mL extractor. The Ogawa PSDs and active samples were extracted with 125 mL of 6%
ethyl ether/94% n-hexane (pesticide quality) for 16 h at 7-12 cycles/h. The EPA PSDs were
extracted with the same solvent in the same manner, except that 250 mL of solvent was
-------
required (4-6 cycles/h). All extracts were concentrated to approximately 10 mL by rotary
evaporation and reduced to a final volume of 2 mL at room temperature under a stream of high-
purity nitrogen. Immediately prior to analysis, the final extract was spiked with an internal
standard consisting of either a mixture of dI4-labeled polycyclic aromatic hydrocarbons for
analysis by gas chromatography/mass spectrometry (GC/MS) or 2,4,5-tribromobiphenyl for gas
chromatography/electron capture detection (GC/ECD). Recoveries of the test pesticides spiked
onto XAD-2 were quantitative. Laboratory and field blanks of both PSDs and the active
sampling cartridge were nearly always below levels of detection.
3. Results and Discussion
The EPA and modified Ogawa PSDs were exposed in triplicate for 3, 6,12, and 21 days in the
test room to vapors of the study pesticides emitted following broadcast spray application of
formulation containing 1% (w/w) each of chlorpyrifos, diazinon, and cis, /ra«s-permethrin
(application rate 1.1 g/m2). In addition, one set of three of each PSD was exposed from day 3 to
day 21 postapplication. Sampling commenced 2 h after application, when the carpet was dry to
the touch. Active samples were also taken in triplicate for sequential 3-d periods starting on
day 1 after application and continuing through day 21. Included also were three field blanks of
each sampler type, which were taken from the preparation area to the exposure room and
returned without opening their containers. The temperature in the exposure room ranged from
17 to 31 °C (mean 21 °C) and the relative humidity varied from 44% to 55% (mean 50%).
Results from the room test presented in Table 1 show that air concentrations were relatively
constant over the 21-d test period, indicating that the room was well sealed. While the air
levels of chlorpyrifos and diazinon, averaging 8.3 and 22.2 |ig/m3, respectively, were higher
than those typically encountered in residential indoor air, they were comparable to those found
in residences within the first several days of an indoor application [15]. Diazinon, which is
approximately four times more volatile than chlorpyrifos, was generally found at levels 3-4
times higher than those of chlorpyrifos. Permethrin, which is a nonvolatile compound, was not
detected in any of the passive samples, but was detected in all active samples at 2-5 ng/m3.
Mean air concentrations calculated from the vapors collected by the EPA PSD agreed very well
with the active sampler data for chlorpyrifos, ranging from 77.5% to 98.8% of the active
measurement (overall mean 85.9%, a = 7.2), although precision between PSDs was poor (21-
38% relative standard deviation [RSD] vs. 4-11% RSD for the active samplers). However, the
results were less favorable for diazinon (range 49.1-70.4%, overall mean 61.9%, 0 = 7.7;
precision between PSDs 8-31 % RSD vs. active 1.5-9% RSD). The low bias for the EPA PSD
may be attributable to boundary layer resistance during quiescent periods in the test room,
where air velocities near the PSDs ranged from 0.2 to 4.2 cm/s (mean 1.2 cm/s) when the heat
pump was off to 6.1 to 116 cm/s (mean 20.8 cm/s) when it was on [2]. Air concentrations
calculated for the Ogawa PSD were 5-12 times greater than the active sampler measurements
for chlorpyrifos and 4-5 times those for diazinon, making it apparent that the device was not
sampling according to Fick's first law of diffusion. Rather than sampling at the predicted 5.9-
6.2 cm3/min (approximately 15% that of the EPA PSD), the Ogawa PSD collected 1-2 times as
much pesticide as the EPA PSD. These data are presented graphically in Figure 2.
The large amount of oversampling by the Ogawa PSDs implies sorption of pesticide vapors by
the materials from which the devices were constructed. This possibility was investigated by
suspending three of the empty PSDs inside sealed 3.8-L metal cans (paint cans) over
approximately 5 mL of the aqueous pesticide formulation contained in open petri dishes. After
three days in the can, the empty Ogawa PSDs had collected 7.5-7.8 jag (mean 7.6 jig) of
chlorpyrifos and 27-29 |ig (mean 28 |ig) of diazinon, some of which may have been from
condensation under the highly humid conditions inside the cans (condensed moisture was
-------
visible on the interior walls of the cans). Simultaneous exposures of empty EPA PSDs also
resulted in collection of lesser quantities of the pesticides, presumably by condensation or
surface adsorption; i.e., 0.8-2.7 pg (mean 2.0 pg) of chlorpyrifos and 4.0-11.0 pg (mean
8.1 pg) of diazinon. Examination of the reconstructed mass chromatograms from the test room
samples revealed a large amount of contamination in the extracts from the Ogawa PSDs,
suggesting an origin in the construction materials. Extracts of EPA PSDs were largely free of
extraneous contamination. It was also observed that the diffusion plates of the Ogawa PSD did
not fit tightly after extraction, suggesting that exposure to the solvent had adversely affected
the plastic. The manufacturer's literature and distributors' Internet sites stated that the Ogawa
Table 1. Comparison of EPA and Ogawa PSDs with active sampler, n = 3.
Active Sampler
Passive Samplers
Estimated* Air Cone., pg/m
Sampling Mean Mass Mean Air
Exposure
Mean Mass
Period,
Collected
Cone.,
Period,
Collected, pg
EPA
Ogawa
Active
Days
pg (%RSD)
pg/m3,
days
(%RSD)
3d
EPA
Ogawa
Chlorpyrifos
0-3
44.5
8.2
0-3
1.3
1.0
8.1
40.0
8.2
(4.1)
(34.3)
(65)
3-6
32.7
6.0
0-6
1.8
4.2
5.5
83.1
7.1
(J.I)
(34.9)
(6.2)
6-9
47.1
8.5
0-12
4.4
7.9
6.6
77.4
7.6
(OS)
(33.5)
(14.5)
9-12
57.1
10.6
0-21
8.2
12.8
7.1
71.9
8.3
(4.4)
(20.9)
(1.1)
12-15
38.2
6.9
3-21
5.7
11.4
6.8
74.5
8.4
(5.4)
(38.5)
(8.9)
15-18
69.8
12.8
(10.6)
18-21
30.6
5.6
(6.1)
Diazinon
0-3
166.8
30,7
0-3
3.7
1.9
21.6
69.6
30.7
(5.0)
(30.6)
(33.9)
3-6
117,2
21.5
0-6
6.0
4.6
17.5
85.7
26.1
(5.6)
(23.8)
(6.0)
6-9
147.1
26.5
0-12
11.6
7.9
16.9
74.3
26.8
(1.5)
(15.4)
(20.3)
9-12
155.6
16.9
0-21
17.1
9.8
14.2
52.2
23.6
(5.5)
(.8.3)
(1.2)
12-15
93.3
26.2
3-21
11.4
8.0
11.0
49.7
22.4
(8.2)
(23.7)
(10.8)
15-18
143.2
10.4
(9.2)
18-21
57.0
23.6
(4.0)
Calculated based on 5.9 and 37.8 crn3/min sampling rates for chlorpyrifos for the Ogawa and
EPA PSDs, respectively; 6.2 and 39.6 cm3/min for diazinon. Air concentrations determined
with the active sampler are mean values calculated from 3-d samples.
-------
Chlorpyrifos
CO
E 70 —
o>
c 60 —
0
1 50 —
C
-------
stainless steel (especially high-carbon types) may also compete with diffusional sampling
processes.
Studies are currently under way to investigate the potential of the EPA PSD construction
materials to collect pesticide vapors from room air. Additional room tests are being conducted
to evaluate the performance of the EPA PSD at lower air concentrations. A 122-cm ceiling fan
has been installed to assure that air velocities near the PSDs are always above 10 cm/s. In
addition, two other devices are undergoing tests: the semipermeable membrane device (SPMD)
developed by the U.S. Geological Survey for water monitoring [18] and the MPS badge, a gas-
sorbent partitioning sampler developed by Midwest Research Institute for organophosphate
vapors. The SPMD, which collects vapors passing through LDPE tubing into triolein by the
processes of permeation and air-solvent partitioning, has been found to be highly efficient at
recovering semivolatile compounds, including pesticides, from ambient air [19]. The SPMDs
currently under study contain 0.25 mL of triolein encased in flat tubes of LDPE measuring 2.5
cm by 15 cm, and have estimated sampling rates for diazinon and chlorpyrifos of 1100 and 660
cnrVmin, respectively. Pesticides collected by the SPMD are recovered by dialysis in «-hexane.
Because of its very high sampling rate, boundary layer resistance may have a profound effect
on the SPMD. The MPS device is a simple 1.6-cm by 3-cm by 1-mm-thick piece of material
made from a proprietary carbon-based mixture cross-linked to a high-temperature polymeric
material that is directly exposed to air. Its estimated sampling rate for the study pesticides is on
the order of 100 cm3/min. Analytes are recovered by extraction with a polar organic solvent.
Also planned are investigation of semipermeable membrane extractors (SPMEs), which can be
used to sample in either the gas-sorbent partitioning or diffusive modes [20, 21]. PSDs with
satisfactory test room performance will be further tested in the EPA IAQ Test House, a single-
story 121 m2 home, and subsequently subjected to field evaluations in occupied homes in
which pesticides are routinely used.
5. Acknowledgments
The authors wish to thank David Stiles and Kathryn Humphries of ManTech for laboratory
support and chemical analyses; David Camann and Alice Yau of Southwest Research Institute,
San Antonio, Texas, for GC/MS analyses; and Robert Coutant, formerly of Battelle, Columbus,
Ohio, for calculation of diffusion coefficients.
This work has been funded wholly by the United States Environmental Protection Agency
under contract 68-D-00-206 to ManTech Environmental Technology, Inc. It has been subjected
to Agency review and approved for publication. Mention of trade names or commercial
products does not constitute endorsement or recommendation for use.
6. References
[1] Coutant RW, Scott DR. Applicability of passive dosimeters for ambient air
monitoring of toxic organic compounds. Environ. Sci. Technol. 1982, 75:410-413.
[2] Lewis RG, Mulik JD, Coutant RW, Wooten GW, McMillin CR. Thermally
desorbable passive sampling device for volatile organic chemicals in ambient air.
Anal. Chem. 1985, 57:214-219.
[3] Spicer CW, Holdren MW, Slivon LE, Coutant RW, Graves ME, Shadwick DS,
McClenny WA, Mulik JD, Fitz-Simons TR. Intercomparison of sampling techniques
for toxic organic compounds in indoor air. In Proceedings of the 1986 EPA/APCA
Symposium on Measurement of Toxic and Related Air Pollutants, Raleigh, NC, 1986,
p. 45-50.
[4] Mulik JD, Lewis RG. Recent developments in passive sampling devices. Chapter 9 in
Advances in Air Sampling, W. John, ed., Industrial Hygiene Science Series, Lewis
-------
Publishers, Chelsea, MI, 1988, pp. 117-131.
[5] Mulik JD, Lewis RG, McClenny WA, Williams DD. Modification of a high-
efficiency passive sampler to determine nitrogen dioxide and formaldehyde in air.
Anal. Chem. 1989, 67:187-189.
[6] Mulik JD, Varns JL, Koutrakis P, Wolfson W, Bunyaviroch A, Williams DE,
Kronmiller KG. Using passive sampling devices to measure selected air volatiles for
assessing ecological change. In Measurement of Toxic & Related Air Pollutants:
Proceedings of the 1993 U.S. EPA/A&WMA International Symposium, VIP-21, Air &
Waste Management Association, Pittsburgh, Pennsylvania, 1991, pp. 428-290.
[7] Koutrakis P, Wolfson JM, Bunyaviroch A, Froehlich SE, Hirano H, Mulik JD.
Measurement of ambient ozone using a nitrite-coated filter. Anal. Chem. 1993,
65:209-214.
[8] Cooper SM, Peterson DL. Spatial distribution of tropospheric ozone in western
Washington, USA. Environ. Pollut. 2000,107:339-347.
[9] Varns JL, Mulik JD, Sather ME, Glen G, Smith L, Stallings C. Passive ozone network
of Dallas: A modeling opportunity with community involvement. 1. Environ. Sci.
Technol. 2001,35:845-855.
[ 10] Whitmore RW, Immerman FW, Camann DE, Bond AE, Lewis RG, Schaum JL. Non-
occupational exposure to pesticides for residents of two U.S. cities. Arch. Environ.
Contain. Toxicol. 1994, 26:47-59.
[11] Tomlin CDS, ed. The e-Pesticide Manual, 12th ed. British Crop Protection Council,
Surrey, UK, 2000.
[12] Fuller EN, Schettler PD, Giddings JC. A new method for prediction of binary gas-
phase diffusion coefficients. Ind. Eng. Chem. 1966, 55:18-27.
[13] Bondi A. Physical Properties of Molecular Crystals, Liquids, and Glasses. John
Wiley & Sons, Inc., New York, 1968.
[14] Lewis RG, MacLeod KE. Portable sampler for pesticides and semivolatile industrial
organic chemicals in air. Anal. Chem. 1982, 54:310-315.
[15] Lewis RG. Pesticides. In Spengler JD, Samet JM, McCarthy JF, eds. Indoor Air
Quality Handbook, McGraw-Hill, New York, 2000, pp. 35.1-35.21.
[16] Weast RC, ed. Handbook of Chemistry and Physics, 57th ed. CRC Press, Inc., Boca
Raton, Florida, 1977, pp. C733-C800.
[17] Reynolds GW, Hoff JT, Gillham RW. Sampling bias caused by materials used to
monitor halocarbons in groundwater. Environ. Sci. Technol. 1990, 24:135-142.
[18] Huckins JN, Tubergen MW, Manuweera GK. Semipermeable membrane devices
containing model lipid: A new approach to monitoring the bioavailability of lipophilic
contaminants and estimating their bioconcentration potential. Chemosphere 1990,
20:533-552.
[19] Petty JD, Huckins JN, Zajicek JL. Application of semipermeable membrane devices
(SPMDs) as passive air samplers. Chemosphere 1993, 27:1609-1624.
[20] Chai M, Pawlisyn J. Analysis of environmental air samples by solid-phase
microextraction and gas chromatography/ion trap mass spectrometry. Environ. Sci.
Technol. 1995,29:693-701.
21 ] Koziel JA, Jia M, Pawlisyn J. Indoor air sampling with solid phase microextraction. In
Proceedings of the Air & Waste Management Association's 93rd Annual Conference
& Exhibition, VIP-97, Air & Waste Management Association, Pittsburgh,
Pennsylvania, 2000, paper #53.
-------
NERL-RTP—HEASD—01-092(a)
TECHNICAL REPORT DATA
1, REPORT NO.
EPA/600/A-02/080
TITLE AND SUBTITLE
Passive/Diffusive Samplers for Pesticides
in Residential Indoor Air
3.
5,REPORT DATE
6.PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
R, G. Lewis, C. R. Fortune, F. T. Blanchard,
and W. D. Ellenson
8.PERFORMING ORGANIZATION REPORT NO,
9. PERFORMING ORGANIZATION NAME AND ADDRESS
U. S. EPA/ORD/NERL, Research Triangle Park, NC 27711
ManTech Environmental Technology, RTP, NC 27709
10, PROGRAM ELEMENT NO.
80201F
11. CONTRACT/GRANT NO.
6 8-D5- 004 9
12. SPONSORING AGENCY NAME AND ADDRESS
National Exposure Research Laboratory
U. S. Environmental Protection Agency
Research Triangle Park, NC 27711
13.TYPE OF REPORT AND PERIOD COVERED
Conference Paper
14. SPONSORING AGENCY CODE
EPA/600/09
15 . SUPPLEMENTARY NOTES
16. ABSTRACT
Pesticides applied indoors vaporize from treated surfaces (e.g., carpets and
baseboards) resulting in elevated air concentrations that may persist for long
periods after applications. Estimating long-term respiratory exposures to
pesticide vapors in residential indoor environments using active (pump-based)
sampling systems has been costly and burdensome on occupants. Diffusion-
controlled passive sampling devices (PSDs), which do not require a noisy pump
and can be situated unobtrusively within the home, would offer distinct
advantages. The U.S. EPA is investigating the applicability of diffusive PSDs,
semipermeable membrane devices (SPMDs), solid-phase microextraction (SPME),
and other gas-sorbent partitioning samplers for estimating semivolatile
organic compound (SVOC) pesticides in homes. This paper presents the results
of the initial evaluations of two diffusion-controlled PSDs for determination
of three pesticides in room air.
17 .
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/
OPEN ENDED TERMS
c.COSA
TI
18. DISTRIBUTION STATEMENT
19. SECURITY CLASS
(This Report)
20. SECURITY CLASS
(This Page}
21.NO.
OF
PAGES
8
22 .
PRICE
------- |