Transport of Lawn-Applied 2,4-D from
Turf to Home: Assessing the Relative
Importance of Transport Mechanisms
and Exposure Pathways
by
Marcia G. Nishioka, Hazel M. Burl&older, Marielle C. Brinkman, Charles Hines
Battelle
505 King Avenue
Columbus, Ohio 4320 1-2693
Cooperative Agreement CR-822082
Project Officer
Robert G. Lewis
National Exposure Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
March 1999
NATIONAL EXPOSURE RESEARCH LABORATORY
U.S. ENVIRONMENTAL PROTECTION AGENCY
RESEARCH TRIANGLE PARK, NC 27711
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Disclaimer
The information in this document has been funded wholly or in part by the United States
Environmental Protection Agency under Cooperative Agreement CR-822082 to Battelle. It has
not been subjected to the Agency's peer and administrative review, and it has not been approved
for publication as an EPA document. In no event shall either the U.S. Environmental Protection
Agency or Battelle have any responsibility or liability for any consequences of any use, misuse,
inability to use, or reliance on the information contained herein, nor does either warrant or
otherwise represent an any way the accuracy, adequacy, efficacy, or applicability of the contents
hereof. Mention of trade names or commercial products does not constitute endorsement or
recommendation for use.
V ••• S:'"
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Foreword
The National Exposure Research Laboratory, Research Triangle Park, North Carolina, conducts
intramural and extramural research in the chemical, physical, and biological sciences. This
research is intended to characterize and quantify ambient pollutant levels and the resulting
exposures of humans and ecosystems; to develop and validate models to predict changes in
pollutant levels; to determine source-receptor relationships affecting environmental quality and
pollutant exposures; and to solve scientific problems relating to EPA's mission through long-
term investigation in the areas of environmental methods, quality assurance, biomarkers, spatial
statistics, exposure assessment, and modeling. The Laboratory provides support to Program and
Regional Offices and state and local groups in the form of technical advice, methods research
and development, quality assurance, field monitoring, instrument development, and modeling for
quantitative risk assessment and regulation. The Laboratory also collects, organizes, manages,
and distributes data on air quality, human and ecosystem exposures and trends for the Program
and Regional Offices, the Office of Research and Development, the scientific community, and
the public.
Traditional considerations of indoor human exposure to pollutants have focused primarily on
indoor use of products containing toxic chemicals and/or infiltration of pollutants from the
outdoor environment. It is becoming increasingly evident, however, that other mechanisms of
contaminant transport are very important. The current work provides quantitative evidence for
the importance of familial activity patterns as significant contributors to the indoor levels of
lawn-applied pesticides following applications. Important activity patterns include the activity
levels of children and pets, and whether outdoors shoes, those of the applicator and the children,
are worn indoors. The data gathered here allow estimates of in-home 2,4-D exposures of
children from the inhalation and non-dietary ingestion pathways.
Gary J. Foley
Director
National Exposure Research Laboratory
Research Triangle Park, NC 27711
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Abstract
Transport of 2,4-D from the residential lawn into the home was measured following both
homeowner and commercial application of this herbicide. Collection of floor dust in five rooms
of each house, both prior to and after application, indicated that turf residues are transported
indoors and that the gradient in 2,4-D surface loading (|ag/m2) through the house follows the
traffic pattern from the entry. Removal of shoes at the door, and the activity level of the children
and pets, were the most significant factors affecting residue levels indoors after application.
Spray drift and fine particle intrusion accounted for relatively little of the residues on floors.
Prior to application, 2,4-D floor dust surface loadings were approximately 0.1 to 5 ng/m2; one
week after application, these levels were 1-228 ng/m2 on carpeted floors in occupied homes, and
0.5 to 2 (ig/m2 in unoccupied homes. Dislodgeable carpet surface residues of 2,4-D were highly
correlated with 2,4-D dust levels, and indicated that approximately 1% of the dust is readily
available for dermal contact. Tabletop levels of 2,4-D were approximately 10% of carpet
loadings, and were largely due to in-home dust resuspension.
Non-dietary ingestion of carpet dust and inhalation for a 1-yr old child in these homes may
produce exposures of 0.04-7 |ig/day. These exposure estimates would be-substantially higher, 4-
70 jig/day, if the non-dietary ingestion was based on contact and transfer from hard surfaces such
as contaminated table tops. In limited cases, these hypothetical exposures would approach the
U.S. EPA IRIS RfD limits for 2,4-D of 10 |ig/kg/day.
iv
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Contents
Foreword iii
Abstract iv
Figures vi
Tables vii
Acknowledgment ix
1. Introduction 1
2. Conclusions 4
3. Recommendations 6
4. Experimental Methods 7
5. Results and Discussion 25
References 59
Appendices
A. Data from First Year Study
B. Data from Second Year Study
C. Data from Third Year Study
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Figures
1. Pesticide transport mechanisms in the residential environment 3
2. Sampling locations and study design for homeowner and
commercial application studies 10
3. Sampling location and study design for temporal intrusion and
exposurestudy 12
4. Air sampling tools for particle size selective sampling 15
5. Schematic representations of PUF roller and HVS3 vacuum samples 17
6. 2,4-D floor loadings following homeowner application 26
7. 2,4-D floor loadings following commercial application 30
8. 2,4-D in indoor air by particle size ranges 35
9. 2,4-D in indoor air by particle size PM2.5 and PM10 36
10. 2,4-D on table tops following homeowner application 40
11. 2,4-D on window sills following homeowner application 41
12. 2,4-D on window sills and table tops following commercial application 42
13. Temporal profile of 2,4-D on table tops, floor and in air for
highactivityhomes 48
14. Comparison of activity patterns and indoor levels of 2,4-D 53
VI
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Tables
1. Sampling Methods used to Link Transport Mechanisms
and Exposure Pathways 8
2. Sampling Sequence at Each Home: Pre-application, Application
and Post-application 13
3. Variations in Extraction/Cleanup Methods for Differing
Media Analyzed 21
4. Recoveries of Herbicide Acids from Sampling Media 24
5. Comparison of 2,4-D. Dust Loadings and Dust Concentrations
for Homes with and without a Carpeted Entry 28
6. Comparison of 2,4-D Loading on Bare Floors with Wipe and
Vacuum Sampling 33
7. Comparison of 2,4-D Air Concentrations by Particle Size 37
8. Ranges of 2,4-D Surface Loadings in Homes: Post-application
Ranges of 2,4-D Surface Loadings along Traffic Gradient of
Each Home 39
9. Correlations Between 2,4-D Air Particulate Levels on Day 3
and 2,4-D Surface Loadings in the Living Area 44
10. Temporal Profile of 2,4-D Intrusion on Floors and Table Tops 46
11. Temporal Profile of 2,4-D on Application and Resident Child Hands 47
12. Temporal Profile of 2,4-D in Adult Applicator and Resident
Child Urine 50
vii
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Tables (Continued)
13. Contributions of Transport Mechanisms to 2,4-D Loadings on
Living Area Surfaces 51
14. Estimated Post-Application 2,4-D Daily Exposure (Non-Dietary
Ingestion and Inhalation) for One-Yr Old Child in Different
Home Environments: Comparison between Four Methods for
Estimating the Non-Dietary Ingestion Component 56
15. Estimated Pre-Application 2,4-D Daily Exposure (Non-Dietary
and Inhalation) for One-Yr Old Child in Different Home Environments:
Comparison between Three Methods for Estimating Non-Dietary
Ingestion Component 58
vm
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Acknowledgment
This work could not have been completed without the cooperation of the participant families
from the Columbus, Ohio area and we thank them for their effort. We also acknowledge the
expertise and assistance of TruGreen-ChemLawn, and in particular Dr. David Martin, in the
second year of the study for providing commercial applications. We acknowledge the use of Key
and Nicholas Homes model homes, and assistance by John Menkedick of Battelle for ANOVA
analyses.
We also wish to acknowledge the encouragement, assistance and review of Dr. Robert G. Lewis
of the U.S. EPA, in serving as the Project Officer, and Dr. Robert Burton of the U.S. EPA, for his
advice and consultation on particle size selective sampling approaches.
IX
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Chapter 1
Introduction
Approximately 80-90% of U.S. households report using pesticides (1,2). With detection of
pesticides in indoor air and house dust months to years post-application, researchers have
concluded that pesticides are highly persistent in the indoor residential environment (3- 10). The
ubiquitous presence of insecticides such as chlorpyrifos and permethrins in indoor air and dust
suggests primary indoor use. However, migration of residues from the house foundation, crawl-
space or basement, and track-in from lawn and garden may be contributory (3,4,5). The
presence of discontinued organochlorine pesticides, such as dieldrin and chlordane, appears to be
due to the infiltration and migration into the home of residues originally applied to foundations
(4,6,7). For 2,4-dichlorophenoxyacetic acid (2,4-D), carbaryl and chlorothalonil, which are
applied exclusively outdoors, their presence indoors implies that residues have been transported
indoors via one or more transport mechanisms, including track-in (i.e., transport via foot traffic).
Recent studies of pesticide levels in the air and house dust of farmers' and farm workers' homes
have shown that pesticide residues are transported from the outside to the indoor environment
(9,11). In one study, organophosphate insecticides were detected in house dust inside the houses
of pesticide applicators living adjacent to the orchard in which they were used, as well as those
of non-applicator farm workers living more than 50 feet from the orchard, and in nearby homes
of families not engaged in agricultural activities (9). Job activity and home location were
interdependent predictors of indoor pesticide levels. Spray drift, volatilization, soil/foliar
resuspension, track-in on shoes and/or transport on clothing are assumed to have played
important roles in the transport of residues.
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Agricultural spray drift of 3-5% of application rates has been measured for nonvolatile 2,4-D
amine formulations (12,13). Soil resuspension rates of a nonvolatile dicamba salt in an aerated
chamber were determined to be 6-8% of the application rate (14). Since both of these
mechanisms involve the airborne transport of submicron to micron (|am) particles and/or aerosols
(15), it is reasonable to assume that tine particles containing 2,4-D can be resuspended from
residential turf by wind, penetrate the exterior of the home through cracks and crevices, windows
and doors, and be deposited on interior surfaces. Field simulated studies following lawn
applications of 2,4-D, chlorpyrifos and chlorothalonil have shown that residential track-in of
pesticide residues can occur, and that walking over treated turf as much as one week after
application results in transport of residues by shoes from turf to carpets. The residues on carpets
following track-in were proportional (3-4%) to the dislodgeable turf residues, and the loadings of
the pesticides on the carpet surface were well correlated with carpet dust residues.(10,16).
The study discussed here was carried out in actual homes to determine the relative importance of
spray drift, foliar resuspension intrusion and track-in of 2,4-D in the residential environment, to
assess the effects of family activity patterns on 2,4-D transport, and estimate potential indoor
residential exposure of young children.
The line drawing in Figure 1 depicts the integration of transport and exposure. As illustrated
there, the application of a pesticide to a lawn can result in transport to the indoor environment by
a variety of factors and mechanisms, and young children inside the home may be exposed to
residues brought indoors by their hand contact with contaminated surfaces. The hand-to-mouth
activities of young children are assumed to be major routes for their non-dietary ingestion of
contaminated materials.
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Residential Pesticide Exposure Scenario
PpVTteNoka/35-*
Figure 1. Pesticide transport mechanisms in the residential environment.
3
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Chapter 2
Conclusions
This manuscript provides data on the extent to which lawn-applied 2,4-D was tracked into actual
homes, and disbursed throughout the floors of the house along the family traffic pattern,
following lawn applications by both homeowners and commercial applicators. It also shows
dislodgeable carpet surface residues of 2,4-D to be well correlated with 2,4-D carpet dust levels
in these homes, suggesting that a portion of the residues transported indoors onto floors may be
readily available for dermal contact.
The inferences that may drawn here are limited by the relatively small number of homes.
However, to the extent that these homes represent the general population, we can deduce that
familial factors (children, pets, and shoes) may have a greater effect on indoor residential
exposures than application factors such as spray drift.
Indoor air, surface wipe and floor dust samples were collected at multiple locations within
occupied and unoccupied homes both prior to and following lawn application of 2,4-D to assess
the relative importance of pesticide transport mechanisms from turf to indoor environment.
Spray drift and foliar resuspension intrusion were minimal contributors (<1%) to indoor levels in
homes with high child and pet activity, but these mechanisms were important (-100%) in homes
with low activity levels and a policy of consistent removal of outdoor shoes. Track-in was the
most significant factor in high activity homes, with the applicator's shoes, the pet, and children
with shoes responsible for ~65%, 25%, and 10%, respectively, for floor levels. Resuspension of
floor dust was the major source of 2,4-D for levels in air (up to 10 ng/m3 in PM10) and on tables
and window sills (-10% of floor levels).
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Four different approaches were considered here to estimate the potential pre- and post-
application exposures of a 1 -yr old child in these homes. Three methods of estimating exposures
assumed non-dietary ingestion (NDI) exposures due to hand-to-mouth transfer of carpet dust, and
the fourth method assumed NDI exposures due to contact and transfer from smooth surfaces such
as a table top. The pre-application exposures (inhalation and NDI) due to carpet dust were
approximately 0.0l-o. 1 ng/day. The post-application exposures (inhalation and NDI) due to
carpet dust were approximately 10-100 fold higher, 0.04-7 &day. Contact with solid surfaces
suggested post-application exposures of 4-70 M-g/day, which is approximately 10 fold higher than
exposures predicted from carpet dust contact and ingestion. Exposures may occur in some
homes shortly after application that approach the U.S. EPA IRIS Reference Dose (RfD) for 2,4-D
(10 ng/kg/day; 100 |ig/day for a 10 kg 1-yr old child).
5
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Chapter 3
Recommendations
The data generated in these field studies suggest that contact with smooth surfaces, followed by
non-dietary ingestion (via hand-to-mouth transfer) may result in exposures 10 fold higher than
contact with carpeted floors. These exposure estimates are based on very limited studies of child
activity patterns and dermal transfer rates. Both activity patterns of children and dermal transfer
rates require additional investigation to refine exposure estimates that might be made from these,
and other, micro-environmental measurements.
In addition, 2,4-D is applied agriculturally to grains, and thus may enter the food chain and result
in dietary exposures. Studies need to be carried out in which 2,4-D is either measured directly in
the foods consumed within the home, or estimated exposure profiles drawn from databases of
residue levels in commonly-consumed foods. These dietary ingestion levels need to be
compared with the non-dietary ingestion levels to elucidate the relative routes of exposure in the
residential environment.
Since exposure must be assessed definitively through the monitoring of biological markers,
studies need to be conducted to compare 2,4-D levels in residents' urine with both dietary and
micro-environmental measurements. In this regard, dietary ingestion rates need to be compared
with non-dietary ingestion rates for better assessment of the relative importance of the several
routes contributing to total or aggregate human exposures.
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Chapter 4
Experimental Methods
Study Design: In designing this study, we assumed that specific sampling methods and sampling
locations inside the home could be used to assess the magnitude and relative importance of
transport mechanisms and exposure pathways. Our linkage of these two concepts is shown in
Table 1. As indicated there, we assumed that spray drift, intrusion of resuspended foliar
residues, and track-in contributed to indoor residue levels. We anticipated that foliar
resuspension intrusion might be detectable in indoor air on the third day post-application, and
lacking that, that this intrusion would result in detectable and equal deposition to floors, sills, and
table tops throughout a house. Track-in would include residues brought in on the applicator's
shoes and clothing, as well as residues tracked in subsequent to the application, and would result <
in a residue concentration gradient from the entry point. In-home particle resuspension (17) could
overshadow distinct intrusion mechanisms, but the differences between homes and between
occupied and unoccupied homes was expected to provide data for the disaggregation of these
effects.
To carry out this design we identified sampling locations through a home, including a frequently
used entry area, a main living area, dining area, kitchen and child's bedroom that would
constitute the primary living spaces of any home. To collect the necessary data, sampling
methods would include vacuum sampling for floor dust residues, wipes of solid surfaces such as
bare floors, table tops and indoor window sills, dislodgeable residue sampling of carpet surfaces,
and air sampling by particle size.
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Table 1. Sampling Methods used to Link Transport Mechanisms and Exposure Pathways
Sampling Method 2,4-D Transport Mechanism Exposure Pathway
2-h Air sampling
Spray drift intrusion
Inhalation
24-h Air sampling
Spray drift/applicator clothing (Dayl)
In-home dust resuspension (Day3)
Inhalation
Inhalation
Air exchange rate
Foliar resuspension intrusion
Inhalation
Sill/table wipe
Foliar resuspension intrusion
In-home dust resuspension
Non-Dietary Ingestion
(NDI)
Dislodgeable carpet
surface residue
Track-in
Dermal Contact/ NDI
Floor dust
(vacuum/wipe)
Track-in
Foliar resuspension intrusion
Ncn-Dietary Ingestion
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Homeowners in the Columbus, OH area who routinely use lawn chemicals were recruited for this
study. Each family consisted of two adults, two to three school-age children, and one pet (one
home had no pets). Homes were single story with basement (except one split level), surrounded
on all sides by turf, and carpeted in the main living room and a child's bedroom. The sampling
period at each home consisted of two one-week periods: a pre-application (background) week,
and a post-application week. Pre-application sampling took place late March through April, and
post-application sampling took place mid-April through mid-June. The post-application week
was initiated by the lawn application of 2,4-D.
The sampling in pre- and post-application weeks was nearly identicial and consisted of indoor air
sampling for 24 hrs on the first and third days (Day 1 and Day 3) of the week; wipe sampling of
sills, tables, and bare floors after a week (on Day 8); collection of a carpet surface dislodgeable
residue sample on Day 8; and vacuum sampling of floors on Day 8. An additional indoor air
sample was collected during the actual 2,4-D lawn application. Deposition coupons on the lawn
were used to estimate 2,4-D application rates. An integrated air exchange rate measurement was
made during the post-application week. All air sampling was conducted in the main living area of
the home. A schematic representation of the sampling locations is shown in Figure 2.
During both the pre-and post-application week, homeowners were asked to refrain from cleaning
(sweeping, vacuuming, mopping) so as not to disturb the normal deposition and distribution of
residues. Since approximately 47% of Americans vacuum floors only once or twice a week (1 8),
standardization of this activity for this study is not inconsistent with typical activity patterns.
Otherwise, families had no constraints on their normal activities. Due to mild weather during the
monitoring period, heating and air-conditioning were not needed; windows were frequently open.
The above sampling design was used in both the first and second years of the study, with
homeowners making their own lawn applications in the first year, and a commercial applicator
making the lawn applications in the second year. Seven families participated in the first year;
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Measuring Transport of Pesticides
Surfaces:
Indoor Air: During Application *\
Day i - 24 hr
Day 3 - 24 hr
Air Exchange Rate - 1 wk
'Turf:
Sill:
Table
Deposition
coupon [c]
Wipe I s l
Wipe 0
Bare floor: Wipe & HVS3
Carpet:' HVS3 <$>
Carpet: PUF Roller &
:>
by particle size, pm
total
<10
<2.5
cl
Figure 2. Sampling locations and study design for homeowner and commercial application
. studies.
10
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four of these families (representing several important activity patterns) were included in the
second year, together with two recently-constructed, unoccupied homes. Homeowners applied
any one of about eight commercially-available post-emergence herbicide formulations consisting
of dicamba, mecoprop and 2,4-D (e.g., KMart K-Gro™), with a desired lawn application rate of
approximately 80 mg 2,4-D/m2. Homeowners used their own application equipment, either a
hose-end sprayer or pressurized pump sprayer. The commercial applicator applied the K-Gro
formulation with a commercial (ChemLawn) spray gun designed to minimize small droplets.
The third year of the study focussed on collection of simultaneous dermal wipe samples, table
wipe samples, and vacuumed floor dust samples on three separate days after the lawn
application. First morning void urine samples were also collected on the morning following each
dermal wipe sample, so as to ascertain whether urinary excretion of 2,4-D could be tied to
microenvironmental levels and/or dermal contaminant levels. The dermal wipe samples and
urine samples were collected from the adult applicator and one resident child. During this study,
families were asked to live as normally as possible, and they were free to vacuum and dust on
their normal schedule. This study included four families. A schematic representation of this
sampling design is shown in Figure 3.
In accordance with HHS regulations, the study design, protocol and informed consent were
reviewed and approved by Battelle's Human Subjects Review Panel.
Sampling Sequence: The sampling events in each home for the studies conducted in the first
two years, and the sequence of events on Day 8, the rooms where samples were collected, and
the areas (or volumes) sampled are detailed in Table 2. As listed there, all sample collection was
carried out in either the entry room (Entry), the central/main living area (Liv) of the home, a
dining room (Din), kitchen (Kit), or a child's bedroom (Bed).
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Measuring Residential 2,4-D Exposure
Application: Homeowner
0 E 0
Applicator Child
Jif
Liv
Air - Appl, Day 1, Day 3
u
Post-Application: Day 1
Day
Air Air
Floor, Table Floor, Table
Hand Hand
2 3 4
Urine Urine Urine
\J
U
[f] Table wipe
0 Vacuum floor
Dermal wipe
U 1st void urine
Floor, Table
Hand
8
Urine
Figure 3. Sampling location and study design for temporal intrusion and exposure study.
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Table 2. Sampling Sequence at Each Home: Pre-application, Application and
Post-application
Day
Sample/Sequence"
Air Volume or Area
Sampled
Roomb
Day 1-
¦ Application
2 h Indoor air
1.76 m3
Liv
Day 1
(Pre and Post)
24 h Indoor air
5.76 m3
Liv
Day 3
( Post)
24 h Indoor air
5.76 m3
Liv
Day 8
(Pre and Post)
Sill wipe
area available
Liv, Dind, Kit, Bed
Table wipe
0.08 m2
Liv, Din, Kit, Bed
Bare floor wipe
0.2 m2; adjacent to
area to be vacuumed
Entry, Din, Kit
(as available)
Dislodgeable carpet .
surface residue
0.48 m2; perimeter of
area to be vacuumed
Liv
Vacuumed dust;
1-2 m2; as available
Entry, Liv, Din,
bare or carpet floor Kit, Bed
a) Samples collected on Day 8 Were collected in the order listed here, with wipe collection of
settled surface dust being collected prior to vacuum collection to avoid contamination of
surfaces with resuspended dust.
b) Room in which sample collected: Liv- main living room, Din- dining room or area,
Kit-kitchen, Bed- child's bedroom, Entry- primary entry area.
c) Samples collected in both pre-application week (Pre) and in post-application week (Post).
d) No samples collected in Din during commercial applicator study.
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Air Sampling: A four-stage cascade impactor sampler (Delron Research Products) was used for
indoor air sampling during application events. It consisted of a series of stages (glass plates
coated with polyethylene glycol 1000 to limit particle bounce) and a final filter (PTFE coated
glass fiber filter, T60A20; Pall/Gelman) separated by impactor jets for the following
particle/aerosol sizes: <1 Jim, 1-2 |xm, 2-8 nm, and >8 |im. The outlet critical orifice provided a
consistent sampling rate of 12.5 L/min with a 370 watt diaphram pump.
Indoor air sampling on the first and third days of each sampling week (Dayl, Day3) was carried
out for 24 h with four collocated samplers (Model 2500; URG), each designed to collect a
different air particulate size: <1 |im, <2.5 (PM2.5), <10 (PM10), and total suspended
particulate (TSP) matter (generally <20 nm). Each sampler consisted of an inlet jet and impactor
plate for particle size discrimination, 27-mm filter (T60A20; Pall/Gelman), and polyurethane
foam (PUF) sorbent trap (27-mm x 76-mm; URG). Impactor plates were oiled with 50 (iL of
silicone oil (Dow-Coming 704). Samplers were located within the breathing zone height, 1.1 m
above the floor, separated from each other by 45 cm, and operated at 4 L/min. Pumps were
placed in a ventilated polystyrene foam box. The volume of sound produced by the URG
sampler pumps was sufficiently low that families could talk and watch television in the same
room.
Schematic representations of these air sampling tools are shown in Figure 4. As shown there, the-
cascade impactor separates a single air stream into four separate particle sizes. Four separate
URG 2500 samplers must be used to achieve the same particle size information. The advantage,
though, to the URG samplers is the fact that all particles less than the designated cut point 'are
collected, rather than a slice of the airstream. Because measured levels are increasingly greater
in each succeeding particle size sample, the chances of detecting low air level concentrations are
enhanced with each successively larger particle size inlet used.
Air exchange and infiltration rates were determined using the Brookhaven National Laboratory
(BNL) Air Infiltration Measurement System, which employs small diffusive perfluorocarbon
14
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Size Selective Air Sampling: Two Approaches
Aerosol
Collected
Air
1-2
Mm CT
cl pm
2-10 pm
Inlet
Glass Plate
> 10 pm Coated with
PEG 1000
Filter
Cascade Impactor
12.5 Lymin for 2 h
Indoor Air
Spray Drift Intrusion
Inlet
Impactor
Filter
PUF
Total
(< 20 pm)
<10
pm
( ( (
<2.5
pm
Aerosol/Particles Collected >
URG 2500 Sampler
4 L/min for 24 h
Indoor Air
Dust Resuspension
<1
pm
Figure'4. Air sampling tools for particle size selective sampling.
15
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tracer sources and small diffusive samplers (19). Sources and samplers were deployed
throughout the homes at the time of applications and retrieved at the conclusion of the one week
sampling period. The 3-zone model was used by BNL in these analyses.
Wine Samnling: A similar sampling method was used for collecting residues from window sills,
table tops and bare floors. A cotton gauze wipe (one-half of a Johnson&Johnson SOF-WICKR
dressing sponge) was moistened with 2 mL of a "sweat simulant" (70:30 phosphate
buffenacetonitrile) just prior to use. The moistening solution bears similarity to sweat in both
the salt content and organic content (20). The designated surface was wiped once in a single
direction, the wipe was then folded to the inside, and the surface was wiped a second time,
orthogonal to the first direction of wipes. The entire flat surface of a window sill was wiped.
Instead of sampling homeowners' table tops, an 850 cm2 FormicaR square was placed on each
designated table surface at time zero each week, for wipe sampling on Day 8. As indicated in
Table 2, a 0.2 m2 area was wiped on bare (uncarpeted) floors. In the first year's study, side-by-
side wipe and vacuum samples were collected from many bare floors. The wipe sample was
collected first, as the vacuum exhaust was likely to disturb adjacent surface residues.
Floor Dust Samnling: The dislodgeable carpet surface residue samples were collected with the
EPA/SwRI Polyurethane Foam (PUF) Roller; floor dust samples were collected using the HVS3
vacuum sampler. Line drawings of these two sampling tools are included in Figure 5. The PUF
Roller and HVS3 have been described in detail elsewhere (3,9). The PUF Roller collection
sleeve was moistened with the aforementioned "sweat simulant". With this solvent mixture, the
otherwise rigid PUF becomes soft, pliable, and slightly moist to the touch, so that the PUF
surface is consistent with the intent of the roller to simulate a child's hand contact with a surface.
(Water-moistened PUF is somewhat rigid, with discontinuous beads of water, and it may not be
a good surrogate for skin.) The carpet surface dislodgeable residue sample was collected around
the perimeter of the floor area to be vacuumed. A single pass with the PUF Roller was made
16
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I
over this area; the sleeve was removed from the core and placed in the zip-seal polyethylene bag
that was used for storage and extraction.
Each floor dust sample was collected by four passes with the HVS3 vacuum over the designated
area, two passes each in orthogonal directions. The sampled area was as close to a 2 m2 area as
possible, while remaining in an area of general foot traffic. Schematic representations of the
floor plan of each home, and the locations where samples were collected, are included in
Appendices A and B.
Dermal Wine Samnling: Homeowners and children were supplied with individually bottled
wipes (a single SOF-WICK gauze), each wipe pre-moistened with 4 mL of a 50:50 mixture of
isopropanol:water. Each participant received their allotment of wipes for the post-application
week in a small cooler containing chemical ice packs (Blue Ice). After wiping their hands for 10
sec, the participants returned the wipe to its individual container. Samples were stored there
during the sampling week. Homeowners were asked to recycle several Blue Ice packs between
their own freezer and the cooler, to maintain temperatures in the coolers. Wipe samples were
returned to the laboratory at the end of the sampling week. The pre-application period consisted
of a single day of sampling, in which participants were instructed how to wipe hands. This one
sample from the adult and the child was returned to the laboratory together with the table top and
vacuumed floor dust samples.
Urine Samples: In a manner similar to the dermal wipe samples, each participant was supplied
with pre-labelled polyethylene urine bottles, that were stored in a small cooler containing two
Blue Ice packs. Homeowners were asked to recycle several Blue Ice packs between their own
freezer and the cooler, to maintain a cool temperature in the sample cooler. Urine samples, eacl
a first morning void sample, were collected in individual polyethylene bottles. Urine samples
were retrieved frequently during the week and returned to the laboratory for storage.
18
-------
Lawn Application Rates: Deposition coupons placed on the lawn consisted of a full
Johnson&Johnson SOF-WICKR dressing gauze backed by aluminum foil, pinned lightly to the
ground. After application, the gauze was placed in an extraction tube, and the foil backing was
rinsed into this container.
Preparation of Samnlinn Media: All SOF-WICK wipes were pre-extracted overnight using
Soxhlet extraction in methylene chloride prior to use. The wipes were dried thoroughly in a
heated vacuum chamber and then pre-packaged in zip-seal bags by home for use. The air
sampler filters were pre-extracted by rinsing with methylene chloride. The air sampler PUF
sorbents were pre-extracted with acetone before use, and then dried in the vacuum dessicator.
The PUF Roller sleeves were pre-cleaned individually by extraction in a zip-seal polyethylene
bag, with solvent squeezed manually through the PUF sleeves ten times. The solvents that were
used in sequence included 200 ml of distilled/deionized water (one extraction; xl), then 150 mL
of 70:30 acetonitrile:phosphate buffer (sodium acid phosphate) pH=3, repeated four times (x4).
Sleeves were squeezed to near dryness and dried further for 30 min using a vacuum dessicator
held at 23-25 in. Hg at 40°C with a stream of dry N2 (approximately 10 mL/min) flowing
through the dessicator. The cleaned filters, wipes, PUF were stored in polyethylene zip-seal bags
at -78°C prior to use.
The cascade impactor plates were cleaned with concentrated acid, rinsed with distilled/deionized
water, and muffled overnight at 450 °C before use. The urine and HVS3 dust collection bottles
were pre-rinsed with high purity acetone and dried. The glass bottles for the dermal wipe
samples were rinsed with acetone and methanol and then muffled overnight before placing
moistened wipes into them.
Samnle Storage: Prior to field use, all pre-cleaned media were stored at -78°C. During field
collection at a home, collected samples were stored in coolers with either dry ice or Blue Ice for
chilling. Environmental media and dermal wipe samples were returned to the laboratory and
stored at -78°C until extraction. Urine samples were stored at 4°C until extraction.
19
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Field and Laboratory OA/OC: All sample media included both blank and spike field and
laboratory QC samples. Each home had a field collected wipe blank and a wipe spike in both pre-
and post-application weeks; a field blank and field spike for the 24 h air samplers. There was
one field blank cascade impactor for the entire suite of homes each year, and one field blank and
field spike of a PUF sleeve for the entire suite of homes each year. All QA/QC results are
detailed in Appendices A, B, and C.
Chemical Analysis Methods: A similar extraction and cleanup methodology was applied to all
environmental and dermal wipe matrices, albeit scaled to the size of the sample type. The basic
methodology is presented below; with variations for each matrix as listed in Table 3.
Each sample was spiked with the 3,4-D as a surrogate recovery standard (SRS) at a level similar
to that expected for 2,4-D, viz., 100 ng for air samples (filters, PUF, plates), surface wipe
samples, dermal wipe samples, and carpet dislodgeable residue samples, and 500 ng for dust,
samples. Samples were extracted with 70:30 acetonitrile:phosphate buffer (0.1 M sodium acid
phosphate) at pH 3. Wipe, filter and impactor plate media were extracted using sonication for
10 min; dust samples were sonicated for 10 min, centrifuged, and 80% of the extract was
removed. PUF samples (air and dislodgeable residue sleeves) were extracted in an appropriately-
sized, zippered polyethylene bag by squeezing the solvent through the PUF.
Distilled/deionized water was added to the extract, the pH was adjusted to 12 with 1M NaOH,
and the extract was partitioned twice with n-hexane. Rotary evaporation at 48°C was used to
remove excess acetonitrile from the PUF sample extracts (80 mL for air PUF and 400 mL for
PUF Roller sleeve), after adjusting to pH 12. Emulsions at the interface of dust extracts were
broken using either NaCl, a few drops of AntifoamR A (Aldrich), and/or by chilling the
20
-------
Table 3. Variations in Extraction/Cleanup Methods for Differing Media Analyzed
Variation in Standard Procedure, Scaled to Size of Sample Matrix
Sample type
Extraction
solvent®
Extraction
method
First water
addition
Hexane
partition
Second water
addition
Air filter
5 mL x 2
Sonicate
loomL
20 mL x 2
100 mL
Air PUF
30 mL x 4
Squeeze
80mL
20 mL x 2
70 mL
Impactor plate
5 mL x 2
Sonicate
100 mL
20 mL x 2
100 mL
Impactor filter
10 mL x 2
Sonicate
100 mL
20 mL x 2
100 mL
Surface wipe
20 mL x 2
Sonicate
360 mL
20 mLx 2
0 mL
PUF Roller sleeve
150 mL x 4
Squeeze
150 mL
25 mLx 2
0 mL
Floor dust
25 mL
Sonicate
100 mL
20 mL x2
80 mL
Dermal wipe
40 mLx 2
Sonicate
0 mL
25 mL x 2
40 mL
a) Solvent volume added and number of repeats.
21
-------
I
separator-y funnel for a few minutes. After discarding the hexane, additional water was added
and a solid phase extraction (SPE) method was used for further cleanup.
An octadecyl hydrocarbon-bonded silica SPE extraction cartridge (C 18 SPE; 6 niL volume, 500
mg loading; Baker) was conditioned in sequence with 10 mL methanol, 10 mL
distilled/deionized water, and 4 mL of 1: 10 acetonitrile: 0.025 M phosphoric acid. The extract
and rinses were loaded onto the conditioned SPE cartridge without allowing the cartridge to go
dry. After loading, the SPE cartridge was air-dried for 2 h on the manifold and then eluted with
2 mL of 1: 1 hexane:diethyl ether (x2).
The SPE eluate was concentrated to near dryness; the internal standard (IS) 2,6-D was added at
the same level as the SRS, the extract was adjusted to 1 mL with 5% methanol in methyl-t-butyl
ether, then methylated with ethereal diazomethane generated in situ from Diazald, carbitol and
37 percent aqueous KOH. After methylation, the solutions were allowed to stand for 30 min.
Dry N2 was used to purge the residual diazomethane; the solution was adjusted to a final 1 mL
volume. Multi-level calibration standards were analyzed concurrently with samples. Samples
that exceeded the. calibration range were diluted, respiked with IS, remethylated, and reanalyzed.
A 100 mL aliquot of each urine sample was spiked with the SRS 3,4-D and analyzed by the
following procedure. A 20 mL aliquot of concentrated HC1 was added to the urine, and it was
heated at 90°C for 1 hr to hydrolyze the protein-conjugated herbicide acids. After, cooling to
room temperature, the sample was transfered to a separator-y funnel, and the pH was adjusted to
pH=12 with 10 N NaOH. The extract was partitioned twice with 25 mL of hexane, and the
hexane extract was discarded. The urine sample was then acidified to pH=l with concentrated
HC1. This sample was applied to a C18 SPE cartridge, which was topped with silanized glass
wool for collection of the denatured protein. The SPE, concentration and derivatization methods
that followed were identical to those described above for the environmental media.
22
-------
I
Sample extracts of environmental media and dermal wipes were analyzed using gas
chromatography with electron capture detection (GC/ECD; Hewlett Packard 5890 GC).
Chromatographic conditions included the following: 60 m DB-5 column (0.25 mm i.d., 0.25 urn
film thickness; J&W Scientific); temperature program from 100-150 °C at 6 °C/min, 150-215 °C
at 2 °C/min, and 2 15-300 °C at 25 °C/min. Confirmation analyses were conducted using GC/MS
with similar chromatographic conditions and full scan electron impact (EI) analyses. The urine
sample extracts were analyzed using GC/MS, with chromatographic conditions identical to those
listed above, in the multiple ion detection (MID) mode. The ions monitored for 2,4-D, 3,4-D and
2,6-D were identical: m/z 234 for identification and quantification, m/z 236 for verification.
Method Validations: Recoveries of dicamba and 2,4-D from the various sampling media were
generally 85-95%, and are summarized in Table 4, Section A. Retention and atmospheric phase
distribution of both free acids and amine salts during 24 h air sampling at 4 L/min with room
temperature air and varying levels of humidity are detailed in Table 4, Section B. The free acids
were found to migrate from filter to PUF sorbent at both 50 and 80% relative humidities (RH).
In contrast, the amine salts, though water soluble, remain largely (>80%) on the filter.
Average percentage recoveries for 3,4-D in field samples were: 99 ± 11 (n=28) for cascade
impactor samples; 96 ± 21 (n=84) for URG air filter samples; 83 ± 23 (n=126) for surface wipe
samples; 93 ± 17 (n=70) for floor dust samples; 99 ± 21 (n=14) for surface dislodgeable residue
PUF Roller samples. Field spike recoveries of 2,4-D were: 92 ± 27% (n=l 1) for wipes, 77 ± 3
(n=2) for air filters, and 80% (n=l) for PUF.
23
-------
Table 4. Recoveries of Herbicide Acids from Sampling Media
Section A: Recovery of Spike, %
Spike of Free Acid
Spike of Amine Salt Formulation
Dicamba
2.4-D
3,4-D
Dicamba
2,4-D
3,4-D
0.5 ng
1 Mg
1 Hg
0.1 ng
1 Hg
1 ^g
Air filter (n=3)
86±2
90±2
99±6
90±1
93±1
95±4
Air PUF (n=3)
84±3
86±3
88±3
93±1
90±1
95±4
Impactor plate(n=2)
82±3
83±2
88±1
92±2
93±1
91±1
Surface wipe (n=2)
68±3
86±1
87±1
NT"
NT
NT
PUF Roller (n=2)
84±6
105±4
105±2
NT
NT
NT
Dust (n=3)
87±2
84±9
93±6
NT
NT
NT
Deposition
Coupon(n=2)
NT
NT
NT
86±3
(6.5 UR)b
89±1
(65 ^g)b
NT
a) NT= not tested
b) spike level equivalent to anticipated lawn application deposition
Section B:
Retention and Distribution with 24 h Air Sampling, %
Free Acid Amine Salt
Dicamba
2,4-D
Dicamba
2,4-D
Temp/humidity1
0.5 \ig
1 Hg
0.1 jig
1 ^g
RT/50% RH: filter
26±3
72±2
81(n=l)
82±1
PUF
57±5
21±1
22(n=l)
NDb
Sum
83
93
103
82
RT/80% RH: filter
13±1
67±1
77±1
85±3
PUF
83±1
30±1
12±2
ND
Sum
96
97
89
85
a) Temperature; RT= Room Temperature; Humidity; RH= Relative Humidity.
b) ND= not detected
24
-------
Chapter 5
Results and Discussion
Establishing Track-In in the Residential Environment: The potential for transport of lawn-
applied herbicides into the home via walking over treated turf was demonstrated earlier in a
series of track-in simulations (10,16). For those demonstrations, at selected times during a one
week period following a lawn application, five adults walked through a defined area of pesticide-
treated turf 20 times each, stepped onto a low, rigid platform after each pass over the turf, and
proceeded to walk across a section of residential carpet before walking over the treated turf on
the next pass. A very good correlation was observed between the dislodgeable 2,4-D turf
residues and both the 2,4-D carpet dust loading (|ig/m2) and the 2,4-D carpet surface
dislodgeable residues, with r2 equal to 0.81 and 0.98, respectively. Based on these results, and
the fact that 2,4-D was present at readily detectable levels in nine (out of nine tested) residential
house dust samples, we designed the present study to verify whether track-in also occurs under
actual residential conditions, and the extent to which it occurs following a lawn application.
The 2,4-D floor dust loadings in six occupied homes are shown in Figure 6. This figure includes
both the pre-application 2,4-D levels and the levels of 2,4-D one week after the homeowner's
lawn-application. Three phenomena are readily identified from these data. First, 2,4-D is
detectable on all floors in all homes one week after the lawn application. Second, 2,4-D is
present on all floors in all homes prior to lawn application; however, 2,4-D floor dust loadings
one week post-application are significantly higher than those levels at the end of the
pre-application week. Third, there appears to be a gradient in the 2,4-D floor dust loading
throughout each home which corresponds to the traffic pattern through the house that family 1
members follow when entering from the outdoors.
25
-------
2,4-D in Floor Dust (pg/m^)
250-
Home A 125-
0
100
Home B50-
0.5
0.6
0.4
117
I
i i Pre-appllcation, Vacuum
Post-application,Vacuum
1 Post-application, Wipe
. Bare Floor
45
<0.1 2
1
25
0-i ¦
100-
Home C 50-
Entry Living Room Dining Room
74
I."
.1 B 0-4
Kitchen'
Bedroom
0.25..
Entry
Kitchen
Living Room Dining Room Bedroom
70
12
.1 0-7 F^I r——
0.3
10
0.5
Li
25.0-1
Home D 12.5-
Entry/Kitchen' Front Hall' Dining Room' Living Room Bedroom
17
LI
<0.1 0.3
0.1 0-7
Entry
Kitchen* Dining Room' Living Room Bedroom
5.0-1
Home E 2.5"
Entry/Hall' Dining Room' Kitchen'
Living Room Bedroom
5.01
Home F 2.5-
0.1
2 2
jM iJI
Kitchen/Entry' Dining Room Living Room Bedroom Family Room
-~Tratfic Flow
C07WWeUf4l'1
Figure 6. 2,4-D floor loadings following homeowner application.
26
-------
I
For completely (or nearly completely) carpeted homes, the 2,4-D floor dust loadings were
highest in the entry area, and dropped to sequentially lower levels throughout the house along the
traffic pattern of the home. This gradient in 2,4-D floor levels from high to low was evident
whether calculated on the basis of 2,4-D surface loading (|ig/m2) or 2,4-D dust concentration
(|ig/g), and is consistent with our expectation of track-in from an external location. This same
gradient in the 2,4-D floor levels was evident in both the pre-and post-application floor dust
samples, although much more pronounced in the post-application period. The average
pre-application 2,4-D level in these homes, 0.5 Hg/m2, is similar to the average level reported
previously for the nine homes in which sampling was done approximately 5-6 months after the
general 2,4-D application period in Columbus, OH. In the main living room area (Liv) of these
homes, post-application levels ranged from approximately 2-200 |ig/m2, or a 4-400 fold increase
over pre-application background levels. [Note: Dicamba was detected in these samples in the
same ratio as found in the formulation, 10% of the 2,4-D level. Dicamba will not be discussed
further because of this similarity. The data for dicamba are listed in Appendices A, B, and C.]
The track-in gradient is most readily discernible in this data set in Homes A and B which had
carpeted entryways and carpeting throughout most of the house. Any bias in accumulation mode
or sampling between bare and carpeted floors may have been largely eliminated by virtue of
having carpeting throughout the house. A slightly different track-in gradient is observed for
homes such as Home C and E (Figure 6) which had a substantial number of uncarpeted floors in
the early sections of the house traffic pattern. Two distinct gradients in 2,4-D floor dust loadings
appeared within these homes: one gradient established for the uncarpeted floor areas and a
second established for the carpeted areas. Note that the bare floor areas (sheet vinyl, wood, etc)
are designated in Figure 6 with an asterisk (*). The post-application 2,4-D loadings on these bare
floors are 5-20 fold lower than the loading on the nearest sequential carpeted area.
Contrary to intuition, the difference in 2,4-D loadings between bare and carpeted areas is due to
factors other than the dust loading, as illustrated by data in Table 5. For representative Home B
27
-------
I
Table 5. Comparison of 2,4-D Dust Loadings and Dust Concentrations for Homes with
and without a Carpeted Entry
2,4-D in HVS3-Collected Floor Dust
Home B: Carpeted Throughout Home C: Many Bare Floors Throughout
Room Floor" 2,4-D 2,4-D Room Floor 2,4-D 2,4-D
Loading, Cone, Loading, Cone,
Hg/m2 Hg/g Hg/m2 |ig/g
Entry
C
74
67
Entry /Kit
V
0.71
1.6
Kit
c
35
57
Hall
W
3.1
1.2
Liv
C
13
28
Din
W
1.7
1.7
Din
C
12
20
Liv
C
70
14
Bed
C
5.3
7.8
Bed
C
27
11
a) Flooring Types: C- carpet; V- sheet vinyl; W- wood.
28
-------
(carpeted throughout), the dust loading was remarkably similar in all rooms (0.5- 1.1 g/m2), and
the single 2,4-D gradient throughout the house was observed in both the 2,4-D loading and the
2,4-D dust concentration. This suggests that if track-in is the primary transport/intrusion
mechanism, the 2,4-D initially tracked into the home at the entry is diluted as it is dispersed
along the traffic pattern. For Home E (having both bare and carpetted floors), not only is the
dust loading low on the bare floors, but the concentration of 2,4-D in that dust (1-2 f-tg/g) is also '
quite low, relative to the concentration of 2,4-D in the carpeted Liv floor dust (14 JJ-g/g). If track-
in was the primary transport mechanism in these homes, then the 2,4-D tracked in at the
beginning of the week, presumably at higher concentrations, is transported to, and accumulates
in, the carpeted areas of the house by in-house activity. The 2,4-D tracked-in later in the week at
lower levels, may be that which was found on the entry floors at sampling time.
The 2,4-D floor dust loadings in homes one week after commercial lawn application are shown
in Figure 7. [Note: Floor dust samples were not collected in the dining area (Din) this time, and
only wipe sampling was used for bare floors.] Trends identified above are again evident. First,
2,4-D was detected, with one exception, in all post-application floor dust samples, including the
floor dust from the unoccupied homes (X and Y). Second, with exception of a few wipe samples
from bare floors, 2,4-D was present in pre-application dust samples, but at levels that were more
variable than in the previous year, ranging here from 0.2-5 |ig/m2. Again, the post-application
levels were significantly higher than pre-application levels. Third, the track-in traffic gradient
was again evident in these.homes. This latter observation indicates that track-in cannot be
attributed solely to track-in upon reentry by the applicator, since in no case did the commercial
applicator come into the house.
Several additional trends were also identified. First, in the main living areas of Homes A and B
there was approximately a three-fold reduction in 2,4-D levels relative to the first study,
contrasted with a three-fold increase in 2,4-D levels in Homes E and F. Since the homeowners
in Homes B, E and F removed or thoroughly rinsed shoes after self-application and
29
-------
2,4-D in Floor Dust (jjg/m*)
100-1
Home A 50-
25.0-1
Home B 12.5-
0.41
Entry
2.50
Unoccupied . ..
Home X
2.50
Unoccupied . ..
HomeY
1
Entry"
25.0-i
Home E 12.5-
0.7 I
I I Pro-application
Post-application
I /1 Not sampled
. Bare floor
32
/ I / l
Entry Living Room Dining Room
Kitchen' Bedroom
1
0.2
0.5
<0.1
I / I / I
0.7 '
05
10.0-
Home F 5.0-
«"¦ J J.
4
J
0.2
0.2
Kitchen Living Room Dining Room Bedroom
I
Entry' Living Room Kitchen* Dining Room Bedroom
0.1
Living Room Kitchen* Dining Room* Bedroom
20
Entry/Hall' Dining Room' Kitchen' Living Room Bedroom
Kitchen/Entry* Dining Room Living Room Bedroom Family Room
>• Traffic Flow
Figure 7. 2,4-D floor loadings following commercial application.
30
-------
before reentry, the differences observed here between homeowner and commercial application
methods may indicate that activity patterns of the family can overshadow the effect of a variable
such as the applicator's reentry into the home. Second, in the four occupied homes participating
in both studies (A, B, E and F), the 2,4-D loadings in the child's bedroom were nearly identical
for homeowner and commercial application. This may suggest that a child will establish an
individualized track-in pattern that is most evident in his/her bedroom. Third, the increase in
2,4-D loadings in the floor dust of the unoccupied homes after lawn treatment may point to
transport mechanisms other than track-in.
Due to the ethical obligation of informing homeowners of results of the first study before inviting
them to participate in the second study, the design of the commercial-applicator study was
somewhat compromised. Changes in family behavior were evident, and the results tended to
confirm the overarching importance of family activity patterns to track-in. In Homes A and B,
greater vigilance was exercised with respect to track-in by pets and children in the first few days
after commercial application. In homes E and F, parental reminders to children to remove shoes
at the door was not enforced as stringently as in the first year of the study, with the higher 2,4-D
floor loadings suggestive of increased track-in of residues. The change in lifestyle apparently
resulted from the E and F homeowners' conclusion, reached upon reviewing the data from the
first study, that they had been overly cautious relative to other participants.
Although Homes X and Y are designated as unoccupied, some traffic did occur in these homes
during the study. In Home X, the builder's agent spent 4 h/day there answering phone calls; this
agent entered through the garage and spent her time indoors. Access to Home Y was more
restricted, although one client inadvertently visited the home near the end of the week. In both
homes, sampling teams made multiple visits to the homes, but limited their potential foot track-in
by removing shoes at the door. These scenarios, in comparison with fully occupied homes,
suggest that the post-application 2,4-D floor dust levels of Homes X and Y were caused
minimally by track-in; other intrusion mechanisms may have been more important, notably
resuspension of 2,4-D from turf followed by fine particle intrusion of the closed house
31
-------
(Home Y), and an incremental addition of fine particle penetration as doors and windows were
opened (Home X).
Comuarison of Wine and Vacuum Sampling for Rare Floors: While not the focus of this
sampling effort, some minor conclusions may be drawn about wipe and vacuum sampling from
data obtained. The surface loadings of 2,4-D are listed in Table 6 for bare floors where both
wipe and vacuum samples were collected. Data are categorized by the sampling time (pre- or
post-application), by the floor type, and whether outdoor shoes were worn indoors.
In the pre-application period, wipe and vacuum sampling appear to give comparable results for
relatively smooth wood floors, as indicated by the ratio approximately equal to 1. The collection
efficiencies of these techniques differ significantly for smooth vinyl and grooved wood (e.g.,
parquet or worn) floors, with wipe collection being more efficient on the vinyl floor. Vacuum
collection gives apparently higher loadings than the wipe on the grooved wood floor, but this is
probably due to collection of dust from within grooves that is not reached by a wipe. Wipe data
may be preferable for comparisons of surface loadings in rooms that have wood floors.
If trends from these limited number of samples are meaningful, it appears that equivalent
efficiency in sampling bare floors shifts in the post-application period. Approximately equal
loadings are now measured in the samples from vinyl floors in cases where outdoor shoes were
not worn indoors, and from grooved wood floors (with or without shoes worn). Data for smooth
wood floors is equivocal. The major difference in collection is observed in 2,4-D loadings from
smooth vinyl floors where outdoor shoes are worn, with wipe sampling providing a more
efficient collection of residues.
Comnarison of 2.4-D Loadings in Dust and Carpet Surface Dislodgeable Residues: We observed
here a very high degree of correlation (1^=0.98) between the 2,4-D floor dust loading (collected
32
-------
Table 6. Comparison of 2,4-D Loading on Bare Floors with Wipe and Vacuum Sampling
Flooring type and
shoes worn indoors?
2,4-D Loading, Hg/m2
Pre-application Post-application
Wipe Vacuum W/Va Wipe Vacuum W/V
Vinyl
yes
no
Wood-smooth"
yes
no
Wood-groovedd
yes
no
0.32
NT
0.08
NT
NT
0.34
0.55
NT
0.32
NT
0.30
0.61
NT
5.74
NT
0.9
NT
0.06
NT
22.7
9.17
0.67
0.56
5.09
NT
2.50
1.58
1.6
0.71
0.59
0.26
1.65
NT
3.13
1.47
14
13
1.1
2.2
3.1
NT
0.8
1.1
a) W/V: Ratio of 2,4-D Loading, Wipe to Vacuum.
b) NT: not tested (sample not collected or no home available with those characteristics).
c) Tongue and groove wood floor with few gaps or breaks in surface.
d) Parquet flooring and/or worn tongue and groove flooring with uneven surface.
33
-------
I
with the HVS3) and the 2,4-D carpet surface dislodgeable residue loading (collected with the
PUF Roller). This correlation appears to hold well despite the diversity of carpet types involved.
The slope of 0.0085 corresponds to an approximate 100: 1 ratio between 2,4-D dust loading and
2,4-D carpet surface dislodgeable residue, and thus implies that aproximately 1% of the dust is
located on the carpet surface and readily available for dermal contact.
2.4-D in Indoor Air bv Particle Size: The averages and ranges of indoor air 2,4-D concentrations
by particle size following homeowner and commercial applications are shown in Figure 8. The
indoor 2,4-D PM2.5 and PM10 concentrations for both applications are shown in Figure 9. The
average data are summarized in Table 7. As seen in Figure 8 and Table 7, concentrations found
indoors during homeowner applications covered more narrow ranges, especially for the two
smallest particle size ranges, than that found on either the first day (Dayl), or the third day
(Day3). Since windows and doors at all homes were open during applications (except at
unoccupied homes), spray drift intrusion was anticipated. The average 2,4-D level in each
particle size range was lower by about a factor of 2 during commercial applications than during
homeowner applications. There was also a significant difference in the <1 nm particle size
concentrations between the two types of applications, but this may have been due to slightly
different collection protocols. For the homeowner applications, a consistent air sample collection
time of 2 h was used. Because this sampling time exceeded the time required for application,
most homeowners completed spray application and reentered the home before the cascade
impactor sampler was stopped. Therefore, from the Application vs Dayl air data alone, we
cannot separate the contributions of spray drift from that of the homeowner reentering wearing
contaminated clothing. For example, much of the fine particulate 2,4-D concentration, especially
<1 pm, in the application sample may have been due to tine particles released from the
homeowner's clothing. [Note: 2,4-D was not detected in any pre-application air sample.]
In the days following both types of applications, most of the respirable concentrations (<2.5 (j.m)
were associated with sub-urn particles. Following homeowner applications, approximately
34
-------
2,4-D in Air by Particle Size, ng/nr
Average Across All Homes
Application:
Homeowner:
Year 1
During Application
2 Hr
13.1
7.5-,
2.5
<1 I - 2 2-8 >8 pm
8.9
7.5 n
Commercial:
Year 2
2.5-
"p rh
Day 1
24 Hr
5-i
4-
3-
2-
1 -
<1 I-2.5 2.5-10 >10 pm
5-
4-
3-
2
1
|-T-' rh i i
Day 3
24 Hr
8.8 6.4
5-i
4-
3-
2-
1
0
cl 1-2.5 2.5-10 >10 Pm
<1 I - 2 2-8 >8 pm
<1 I-2.5 2.5-10 >10 pm
5-.
4-
3-
2-
1
0
-J- rn
<1 I-2.5 2.5-10 >10 pm
Figure 8. 2,4-D in indoor air by particle size ranges.
35
-------
I
Application:
Commercial:
Year 2
2,4-D on PM2.5 and PM10 Particles, ng/rrf
During Application
2 Hf
17.7
Homeowner:
Year 1
10
8
6
4
2
0
10
8-
6-
4-
2-
I -
pm2^ pm10
3xl
y 12.1
_CtL
pm15 pm10
10
t
•
4
2
0
10
8
6-
4-
2
0-
Day 1
24 Hr
PMjj PM,
1-2x
m
PM2j PM
10
8
6
4
2
0
11
3
«
4-
2-
0-
Day 3
24 Hr
10.8
jh
PMj.5 pm10
jl-2x
pm2.5 pm10
Figure'9. 2,4-D in indoor air by particle size PM2.5 and PM10.
36
-------
Table 7. Comparison of 2,4-D Air Concentrations by Particle Size
A:Homeowner Application Application Dayl Day3
2,4-D TSP Concentration, ng/m3 13.5 9.2 8.7
PM Size Range Deposition Distribution of Total 2,4-D by Size Range, %
<1 Jim
alveoli
14
9
9
1-2.5 Jim
(1-2 Jim for application)
alveoli
15
13
5
2.5-10 |im
(2-8 Jim for application)
trachea/larynx
43
33
33
>10 (im
(>8 (am for application)
nose/mouth
28
45
53
PM Size
Designation
Percent of Total 2,4-D, %
PM2.5 (<2.5 |im)
respirable PM
29
22
14
PM10 (<10 pm)
inspirable PM
72
55
47
B: Commercial Application
Application
Dayl
Day3
2,4-D TSP Concentration, ng/m3
7.8
2.7
3.8
PM Size Range
Deposition
Distribution of Total 2,4-D, %
<1 nm
alveoli
0
'64
46
1-2.5 Jim
(1-2 Jim for application)
alveoli
15
5
2
2.5-10 Jim
(2-8 Jim for application)
trachea/larynx
53
8
14
>10 Jim
(>8 Jim for application)
nose/mouth
33
22
38
PM Size
Designation
Percent of Total 2,4-D, %
PM2.5 (<2.5 Jim)
respirable PM
15
69
48
PM10 (<10 nm)
inspirable PM
68
77
62
37
-------
65% of the 2,4-D found on TSP was associated with inspirable particles (<10 pm), and 25% was
on respirable particles (<2.5 urn). Following the commercial application, approximately 75%
was inspirable, and 70% was respirable. It is interesting to note that approximately the same
level of 2,4-D on <1 |i.m particles was found in indoor air following both application methods,
despite the absence of these particles during the initial application event by the commercial
applicator.
Following homeowner applications, calculations of 2 h vs. 24 h air levels suggested that on Dayl
for active homes and homes where the applicator wore shoes indoors, only 25% of the indoor air
level could be attributed to intrusion during the first 2 h; in contrast, in a low activity home
where the applicator did not wear shoes indoors, 100% of the Dayl air level could be attributed
to 2,4-D intrusion during the first 2 h.
When examining the air data on a home by home basis, the higher 2,4-D air levels were
associated with homes with active children and pets, and especially with those where shoes were
also worn indoors. Likewise, the homes where 2,4-D was not detected in air were those with
low levels of activity and/or no shoes worn indoors.
2.4-D on Table Tods and Window Sills: The 2,4-D was not detected on table tops during the
pre-application period, and on only three (out of 40) window sills. However, 2,4-D was detected
at measurable levels on all sills and table tops at the end of the post-application period in all
homes, with the minor exception of a few sills and table surfaces in one unoccupied home. The
ranges of post-application surface loadings on floors, tables and window sills in each home are
listed in Table 8. These levels are depicted in graphical form in Figures 10-12. Figures 10 and
11 show the pre- and post-application levels of 2,4-D on table tops and indoor window sills,
respectively, by home and by room in the homeowner-application study. Figure 12 shows the
post-application levels of 2,4-D on window sills and table tops in the commercial applicator
study.
38
-------
Table 8. Ranges of 2,4-D Surface Loadings in Homes: Post-application Ranges of 2,4-D
Surface Loadings along Traffic Gradient of Each Home
Range of 2,4-D Surface Loadings, ug/m2
Carpeted
Bare
Window
occupancy
Home
Application
floor
floor
Table
sill
Occupied
A
Homeowner
228-25
45
27-6.4
22-4.8
A
Commercial
76-32
7.9
10-3.2
8.2-2.6
B
Homeowner
74 - 5.3
NS"
5.1 -2.1
3.4- 1.7
B
Commercial
24 - 5.2
NS
2.5 - 1.9
1.8-1.2
C
Homeowner
70-27
12-5
3.1 - 11
3.8-1.1
D
Homeowner
17-4.5
0.7 - 0.3
2.0 - 1.4
2.0 - 0.6
E
Homeowner
5.0-3.6
2-0.7
4.8 - 1.3
1.4-0.9
E
Commercial
20 - 5.0
3 - 1
4.8-0.8
3.9-0.5
F
Homeowner
1.9-1.2
0.2
3.5 -0.5
1.9-0.8
F
Commercial
6.5 - 4.4
2.2
1.3 -0.9
5.7-0.5
Unoccupied X
Commercial
1.9-0.8
1.0-0.8
0.8-0.4
0.2-0.02
Y
Commercial
0.5 - 0.05
1.0
ND, co.02
ND, co.02
a) NS- not sampled; no bare floors in designated areas.
39
-------
Spatial Distribution
2,4-D on Tables After 1 Week Accumulation (/ig/m2)
Horns A
10
Homo B
I ¦ I ¦ ¦ | rj rj jrJI
Diing Uving Kitchen Bedroom living Kitchen Dining Bedroom
Pm-application
H Post-application
0 Not Detected, <0.1
Kitchen Dining Bedroom
Home C
Home D
Ding Living Kitchen Bedroom
ILli
Bedroom Hal Uving Dining
s -I
Home E
Oil,
Family ii»i.» Kitchen Bedroom
Home F
Ding Living Bedroom Family
Figure 10. 2,4-D on table tops following homeowner application.
40
-------
Spatial Distri bution
2,4-D on Sills After 1 Week Accumulation (/ig/m1)
50 -i
40-
30-
Home A
Home B
20-
10-
10-
8-
6
4'
~ Pm-application
¦1 Past-application
0 Not Detected, <0.04
LMng Kitchen Bedroom Bedroom
Back Bide
LMng Dining Kitchen Bedroom
Home C
5
4-
3-
Home D
Living Diing Kitchen Bedroom
Url-TL
Dining LMng Bedroom Bedroom
Side Back
5"1
4,
3 -
Home E
Home F
2.
2.
n4i *-• | rJ rtM n rrm rJ rJ rjJ
Family Bedroom Kitchen • Dining livina Bedroom Kitchen Family
living Bedroom Kitchen Family
WMUtMflu
•Sample Lost
Figure II. 2,4-D on window sills following homeowner application.
41
-------
2,4-D Loading on Surfaces (|jg/mz)
after Commercial Lawn Application
Home A
Home B
Unoccupied
Home X
Unoccupied
Home Y
Home E
Home F
Table
Sill
10-1
Liv Kit Bed Llv Kit Bed
5-1
111 ¦
Kit Liv Bed Kit Liv Bed
5t
nd
nd
Liv Kit Bed Liv Kit Bed
5-1
nd nd nd
nd nd nd
Liv Kit Bed Liv Kit Bed
111-
Kit Llv Bed
I 1
Kit Liv Bed
5-1
Kit Liv Bed
Kit Liv Bed
CQ7*a— w
-------
As shown in these figures, in most homes the 2,4-D levels on sills and table tops showed a
gradient similar to that seen for the floor loadings, from high to low with the direction of traffic
through the home. In those homes exhibiting pronounced gradients (e.g., homes A, B, and C),
the 2,4-D loadings on tables and sills were approximately 10% and 8%, respectively, of the floor
loadings. The observation of traffic-dependent gradients in table and sill surface 2,4-D loadings,
combined with the levels of activity in these homes, strongly implies that dust resuspension
within the home was the major source of 2,4-D residues found on sills and tables. The 10 to 1
ratio here of floor to table 2,4-D surface loadings closely resembles the 10: 1 ratio for
resuspension rates by activity: 10" h~' for normal traffic and play and 10"4 h"1 for reading (10). In
one home carpeted throughout, and thus a similar surface for resuspension, post-application
2,4-D floor loadings were highly correlated with both sill and table loadings, 1*= 0.82 and 0.95,
respectively.
The 2,4-D loadings on surfaces in the principal living area and the 2,4-D air concentrations were
compared, and correlations among the matrices are listed in Table 9. Correlations are high
(>0.85) between surface loading and 2,4-D TSP and PM10 concentrations, and poor between
surfaces and 2,4-D PM2.5 concentrations. These results are consistent with other reports that
deposition of larger particles contributes more to surface loadings than smaller particles (21).
For several homes characterized as having limited child and pet activity and/or homes where
shoes were not worn indoors, the gradient on the sills, and to some extent on the tables, was
barely evident (e.g., homes E and F with homeowner application). In these homes, the 2,4-D
loadings on floors, sills, and tables were comparable and generally in the range of 1-2 Hg/m2.
These consistent levels of 2,4-D on all surfaces are suggestive of foliar resuspension intrusion,
and are low compared with the levels that were found following resuspension of floor dust in
high activity homes, up to 25 ng/m2.
43
-------
Table 9. Correlations Between 2,4-D Air Particulate Levels on Day 3 and 2,4-D Surface
Loadings in the Living Area
Pearson correlation: 2.4-D Liv surface loading (ug/m2) and 2.4-D air level (ng/m3)
Surface TSP PM10 PM2.5
Table 0.96 0.90 0.46
Window sill 0.93 0.87 0.44
Floor 0.89 0.88 0.45
44
-------
Temnoral Profile of Intrusion: The data gathered in the third year of the program were used to
assess the temporal profile of intrusion and appearance of residues on table surfaces. Data were
collected at four homes, each with a distinctly different set of family activity patterns. Despite
the differences in activity patterns, especially with respect to cleaning and vacuuming, which
were allowed this time during the one week post-application period, there was still a distinct
trend in accumulation in all homes. The intrusion and accumulation of 2,4-D on the living room
floor and living room table continued through the sampling week, albeit at different rates for the
four homes. The totals by week's end and the percentage of that total accumulated between
each sampling period (application to Dayl, Dayl to Day3, and Day3 to Day7) are listed in
Table 10. As shown there, the peak accumulation on the table top follows after the peak
accumulation on the floor. This finding is consistent with earlier data suggesting that most of the
residues on tables comes from resuspension of material originally tracked-in onto the floor.
The 2,4-D levels on the hands of the adult applicator and the resident child are listed in Table 11.
There were substantial differences, a factor of 2000, between the levels on the different
applicator's hands, from as little as 29 ng on the hands of the applicator wearing heavy gloves to
57 fig on the hands of the applicator not wearing gloves. Over the one-week sampling period,
the 2,4-D levels on the applicator hands declined to approximately 2X pre-application levels.
The levels on the children's hands showed some apparently different trends. In the high activity
home, the levels on the child's hands appeared to increase throughout the week, as did the floor,
air and table residue levels. In the other homes, the levels on the child's hands varied throughout
the week. In one case the level was highest on the day of application, possible from touching
contaminated clothing. The comparison of 2,4-D levels in air, on surfaces, and on hands for the
high activity home is shown in Figure 13. There was a substantial amount of rain at this home
24 h after application; despite the wash-off effect of the rain in removing turf residues, there
were sufficient residue levels remaining for track-in over the remainder of the week.
The urine analysis method remained problematic, and we do not ascribe much significance to the
data, albeit to show trends. The total 2,4-D amounts excreted in the first morning void of
45
-------
Table 10. Temporal Profile of 2,4-D Intrusion on Floors and Table Tops
Home Activity Descriptors" Surface 7-day Cumulative Accumulation, %
Loading, jig/m2
D1
D3
D7
By
HiC
HiP
S
As
Floor
17
35
43
21
Table
3.1
6
30
64
Zm
ModC
LoP
S
NAS
Floor
4.1
15
59
26
Table
1.6
13
34
53
Rr
HiC
LoP
NS
NAS
Floor
2.5
62
30
8
Table
0.12
nd
58
42
cs
LoC
LOP
s
NAS
Floor
2.4
14
36
50
Table
0.12
nd
42
58
a) activity descriptors:
HiC- high child activity,
ModC- moderate child activity
LoC- low child activity
HiP- high pet activity
LoP- low pet activity
S- family outdoor shoes worn indoors
NS- family outdoor shoes not worn indoors
AS- applicator shoes worn indoors
NAS- applicator shoes not worn indoors
46
-------
Table 11. Temporal Profile of 2,4-D on Application and Resident Child Hands
Total 2,4-D on Hands, ng
Home Subject Pre-Appl. Post-Appl. Post-Appl. Post-Appl.
Dav 1 Day 3 Day 7
BY
adult
26
56,900"
378
51
child
100
10b
95
1060
Zm
adult
1740"
28,300
864
179
child
17
92
8
53
Cs
adult
ndd
29"
40
25
child
n d
ndf
68
nd
Rr
adult
24
927
600
52
child
46
41
nd
22
a) Application made just before dinner; applicator finished job and then wiped hands for
sample.
b) Child not at home during application (at swim practice); came in and wiped hands for
sample.
c) Residual level from application made 3 weeks earlier (washed out by heavy rains within 12
hours of application, so reapplied).
d) By the looks of the lawn, no 2,4-D had been applied for 1-2 years.
e) Applicator wore gloves during application.
f) Child not at home during application.
47
-------
2,4-D Temporal Profile
in High Activity Home
Figure 13. Temporal profile of 2,4-D on table tops, floor and in air for high activity homes.
48
-------
applicator and child are listed in Table 12. As shown there, the applicator values rise about 500
ng over background within the first few days, and return to baseline, and this is consistent with
literature values of -36 h half-life. The excretion profiles of the children also seem to show an
increase over background levels within the first few days after application. Since the air levels,
as determined from the stationary micro-environmental samplers, do not indicate sufficient
exposure levels for these biomarker levels, we assume that the personal inhalation exposure
levels of the children were significantly higher than what might be inferred from the central air
monitoring location. It remains possible that contact with the applicator or a trip across the lawn
may have been responsible for the urine levels. There does not appear to be a correlation with
dermal wipe amounts; however, this results was not unexpected, as the children were typically
10-12 yrs old, and not prone to extensive hand-to-mouth activity. Their dermal wipe levels,
though, may be better used to assess their contact with contaminated surfaces. In that regard, the
children's hand wipe data and table surface loadings are moderately well-correlated: ?= 0.73 for
a linear fit and 1^=0.97 for a polynomial fit. Using recently derived transfer coefficients and
contact areas (22), it appears that children may have contacted hard surfaces 10-100 times before
hands were wiped.
Role of Activity Patterns: The two-year study presented above is limited by the small number of
homes studied. However, the extent to which these homes represent important trends and factors
in the general population, we hypothesize that familial factors have a greater effect on transport
and residential exposure than application factors such as spray drift. In particular, the levels of
child and pet activities, and whether family members wear their outdoor shoes indoors are the
factors that were significantly different among these homes. A multivariate analysis, with
ANOVA, was used to deconvolute the data into the contributions from different activities to the
post-application 2,4-D loadings on the floor, sill and table top surfaces of the main living area.
The incremental contributions of these factors are listed in Table 13. As shown there, a high
activity dog and the applicator's shoes worn indoors were the most significant factors, followed
49
-------
Table 12. Temporal Profile of 2,4-D in Adult Applicator and Resident Child Urine
Total 2,4-D Excreted in First Morning Void, ng
Home
Subject
Pre-Appl.
Post-Appl.
Day 2
Post-Appl.
Day 3
Post-Appl.
Day 4
• Post-Appl.
Day 8
BY
adult
1097
1116
1568
1220
655
child
107"
78
597
503
198
Zm
adult
116"
419
220
405
65
child
625(?)a,b
190
175
714
288
Cs
adult
1875(?rb
199
159
615
237
child
109"
405
876
316
nd
Rr
adult
2122(7)^
1208
836
300
560
child
97"
a) Analysis using GC/ECD rather than GC/MS.
b) ? - suspect value; not repeated with GC/MS analysis.
50
-------
Table 13. Contributions of Transport Mechanisms to 2,4-D Loadings on Living Area
Surfaces
Parameter
Application
Spray drift
Ventilation of home
Closed home8
Open homeb
Track-in
Applicator shoes
High activity children
with shoes
Moderate activity children
with shoes
Ug/m2
-0
0.3
1.4
50.5
8.7
17.3
2.4
-0
0.1
0.4
-0
5.3
5.1
4.2
4.1
% of total
Floor Table Sill Floor Table Sill
-0
0.1
1.2
2.4
2.5
2.5
2.5
0.2 0.4 0.4
0.8 0.7
27
-0
18
Low activity children
with shoes
-0
3.0
0.3
0.1
0.4
0.5
Low activity dog
13.7
3.0
3.4
High activity dog
.17.5
22.8
18.4 63
80
80
a) Closed home intrusion through cracks.
b.) Open house intrusion via opening/closing of doors and windows.
c) Calculation of parameter distribution limited to high activity children with shoes and high
activity dog.
51
-------
I
by high activity children and their shoes. Only the high pet activity factor and applicator's shoes
were significant at p<0.05 confidence level.
The applicator's shoes contributed significantly to floor loadings (27%), but less so to levels on
sills and tables (0-5%). Instead, the activity levels of children and dogs seemed to drive the
loadings on the sills and table, and this presumably through the resuspension of floor dust during
their play. In fact, an active dog may have been responsible for 63% of the residues on the floors
and 80% of the residues on the tables and sills one week after lawn application.
While the absolute contributions or relative order of these parameters in affecting indoor levels
may not have been predicted intuitively, the results appear consistent with our understanding of
family dynamics. In particular, the high activity homes studied were those with at least two boys
in the 8-12 age bracket who were within two to three years of each other in age and who had
friends in the immediate neighborhood. In the case of the home with the high activity dog, the
dog was in contact with the treated turf within an hour of application, whereas children were not.
Turf Application Rates and Air Exchange Rates: The application rates and air exchange rates
may also affect indoor air and surface levels. Five of the seven homes at which homeowner
applications were made had similar air exchange rates, 250-300 m3/h; one was substantially
higher, 400 m3/h, and one was substantially lower, 125 m3/h. The manufacturer-suggested
application rate of 80 mg/m2 for 2,4-D was rarely achieved. Most deposition coupons indicated
application rates of 30-70 mg/m2, and many homeowners deliberately applied less in areas where
children played frequently. Deposition rates at one home averaged 150 mg/m2 and rates at
another home were extremely low, 10 mg/m2 and this was probably due to the fact that
application was made on a slightly windy day.
Effects of Activity Patterns on Indoor Levels: The post-application levels of 2,4-D in three
homes are shown in Figure 14. This figure presents the levels on floor, table and sill surfaces, air
52
-------
2,4-D
Concentration
On floor,
Home A
Home E
Home £
pg/m1
On table,
pg/m'
On window
sill, pg/m'
200
In living
room air, ng/ms
Lawn application
rate, mg/m'
Air infiltration
rate, m'/hr
Activity descriptors
Llv Din Kit' Bed
Din' Kit* Llv Bed Klt/DIn* Llv Bed Fam
30-
Llv Din Kit Bed
25
5 n
NS
Dirt Kit Llv Bed Kit/Din Llv Bed Fam
JZL
20
Llv Din Kit Bed
Day 1 Day 31
Din Kit Llv Bed* Kit/Din Llv Bed Fam
7.5 -i
I
~ay 3 a Day 1 Day 3__
-I rrlrTI
PM, HI, TSP Pm, PM„ TSP
43 ±13
247
HiC, HIP, S, AS
PM, PM„ TSP PM„ PM„ TSP
31 ±36
254
HiC. LoP, NS, NAS
5 i
Day 1 Day 3
nd
PM, PM„ TSP PM, PM, TSP
158 ±108
127
LoC, LoP, NS, NAS
Figure l4. Comparison of activity patterns on indoor levels of 2,4-D.
53
-------
levels on Dayl and Day3, lawn application rate, air infiltration rate, and the activity descriptors
for that household. As shown there, the household with the highest lawn application rate (F) also
had the lowest air exchange rate, the lowest indoor residue levels, and occupants consistently
removed shoes upon entering the house. In a home with high child activity and a no-shoes
policy (E), indoor residues were also low. In contrast, the home with an active dog and children,
and shoes worn indoors, had significantly higher indoor levels despite application rates and air
exchange rates equivalent to Home E. It appears, therefore, that homeowners can control a
large portion of 2,4-D intrusion into the house through a strict "no outdoor-shoes worn indoors"
policy. Control over track-in by a dog is more difficult, although the homeowners with the high
activity pet were able to limit its activity level when participating in the second study.
Control of Intrusion:To limit intrusion of this pesticide into the home, it may be advisable to
limit the contact of indoor-outdoor pets with the treated turf, and/or to wash the animals
frequently in the first week after lawn treatment. It also appears that homeowners can apply lawn
care products with no more indoor intrusion occuring than with commercial applications if the
applicator's shoes are removed before he/she enters the home. Although the role of his/her
clothing, such as contamination on pant legs, could not be deduced from the small data set here,
it appears reasonable to suggest that use of coveralls that are removed before reentering the house
can also limit track-in intrusion of pesticides. Finally, consistent removal of shoes at the door not
only by the applicator, but by all family members, appears to result in substantially lower track-
in of lawn-applied chemicals.
The use of an entry mat and uncarpeted floors has been suggested (23), together with other
control measures, as ways to limit track-in of pollutants and accumulation, and thereby reduce
the potential for childrens' indoor exposures via dermal contact and non-dietary ingestion (hand-
to-mouth) of dust while playing on floors. These data provide an interesting corollary, in that a
carpeted entry, where children are less likely to play, may serve as a retainer for tracked-in
pollutants, and prevent their migration into carpeted living areas where children may play.
54
-------
Uncarpeted entries, or bare floors with a smooth-surface or short-pile entry mat, may only
exacerbate the migration of pollutants into carpeted living areas.
Estimating Indoor Exposure: Four different approaches for estimating the pre- and post-
application inhalation and non-dietary ingestion exposures of a 1 -yr old are given for comparison
in Table 14. The dermal penetration route was not considered here because of the low skin
permeability (<3%) of the 2,4-D amine salt (24). For post-application exposures, the Day 3
PM10 air level in the home and an 8.7 m3/day inhalation volume was used for each approach
(18). For non-dietary ingestion, the first approach combined the 2,4-D dislodgeable surface
loading determined with the PUF roller and assumed that the average area of both of a 1-yr old
child's hands to be 0.031 m2 (18). It also assumed 12 h of activity/day with essentially
continuous contact of the hands with the living area floor, and 10 hand-to-mouth events/h (25).
The second approach employed the current U.S Environmental Protection Agency estimate of
100 mg of dust ingestion/day (18). The third method used human activity descriptors associated
with the household to estimate a 2,4-D carpet loading, with extrapolation to a dislodgeable carpet
surface loading. This value was then combined with a child's total hand area and rate of hand-to-
mouth used in the first scenario. Whereas the first three estimations were based on contact with
the living room floor, the fourth approach to estimating exposure was based on surface loadings
of 2,4-D on the living room table. For that one, an 80% dust transfer rate (22) was combined
with the hand area and activity rates used in the other scenarios. The first three methods were in
excellent agreement, especially the PUF Roller and EPA dust ingestion approaches, this due in
part to the very high degree of correlation (1^=0.98) between the 2,4-D carpet dust loadings and
dislodgeable carpet surface loadings. The Pearson correlations between exposure estimates
demonstrate this parity; r=0.90 for PUF Roller vs 100 mg dust ingestion and r=0.93 for 100 mg
dust ingestion with activity descriptors. The major differences in exposure estimates between the
PUF Roller and 100 mg dust ingestion method appeared in those homes where the dust loadings
were low. Measured dust loadings were 0.2-10 g dust/m*. In homes with the lower dust
loadings, the 100 mg dust ingestion rate may tend to overestimate the non-dietary ingestion.
55
-------
Table 14. Estimated Post-Application 2,4-D Daily Exposure (Non-Dietary Ingestion and
Inhalation) for One-Yr Old Child in Different Home Environments: Comparison
between Four Methods for Estimating the Non-Dietary Ingestion Component
Estimated Combined Inhalation and Non-Dietary Ingestion Post-
Application Exposure fug/day) based on: a
Home Activity Descriptors
PUF
Roller1'
100 mg Dust
Ingestion"
Activity
Descriptors'1
Contact with
Smooth Surface6
HiP AS
HiC
Sf
6.4
6.8
7.0
67
LoP NAS
HiC
s
2.9
1.9
1.2
28
LoP AS
HiC
s
1.4
1.4
3.1
7.6
LoP NAS
HiC
s
0.73
0.83
0.90
13
LoP NAS
LoC
s
0.52
0.63
0.68
4.8
LoP NAS
ModC S
0.38*8
2.8
0.99
14
LoP NAS
HiC N S
0.38
1.0
0.90
13
LoP N A S
LoC N S
0.21
0.75
0.57
3.7
LoP NAS
ModC
s
0.09*
1.1
0.99
7.2
LoP N A S
LoC N S
0.08*
0.81
0.57
4.8
LoP N A S
LoC S
0.04*
0.50
0.68
6.0
Mean exposure, Hg/day
1.2
1.7
1.6
16
Median exposure, ^day
0.38
1.0
0.9
Exposure Range, ng/day
0.04-6.4
0.5-6.8
0.57-7.0
3.7-67
a) Inhalation exposure: Pre-application =0; Post-application = PM10 2,4-D Day3 concentration
(ng/m3) x 8.7 m3/day inhalation volume.
b) Non-dietary ingestion (NDI) exposure = 2,4-D dislodgeable carpet surface loading (ng/m2)x
average 1 -yr old child hand area x 10 hand-to-mouth events/h x 12 h/day.
c) NDI = 0.1 g dust ingestion /day x 2,4-D concentration in dust (ng/g).
d) NDI = sum of 2,4-D floor loadings due to activity descriptors x 0.01 (ratio of 2,4-D PUF Roller
loading to 2,4-D carpet dust loading) x hand area x 10 hand-to-mouth/h x 12 h/day.
e) NDI= 2,4-D Liv table surface loading (ng/m2) x 80% transfer rate x hand area x 10 hand-to-
mouth/h x 12 h/day.
f) Activity descriptors: HiP= high pet activity; LoP= low pet activity; AS= applicator's shoes worn
indoors; NAS= no applicator shoes worn indoors; HiC= high child activity; S= shoes worn
indoors by family; NS= no shoes worn indoors by family.
g) Homes for which significant difference exists between estimated exposures based on PUP Roller
dislodgeable residues and 100 mg dust ingestion.
56
-------
The exposure estimates based on contact with the table tops (fourth scenario) were higher than
floor dust exposures by a factor of 10. If dermal contact and hand-to-mouth activity are limited
to a single palm, the exposures are approximately twice the values obtained with the floor dust
ingestion estimates. These estimates suggest that contact with smooth surfaces may be a more
significant contributor to non-dietary ingestion that previously considered.
In the post-application period, the inhalation component was small, relative to the non-dietary
ingestion component. Where shoes were worn indoors, inhalation exposure was 0-2% of the
total estimated exposure; for the homes where shoes were not worn indoors, inhalation exposures
were about 10% of the total.
The pre-application exposure estimates shown in Table 15 were limited to a few representative
homes. These exposures estimates were approximately 0.0 l-o. 1 ng/day, a factor of 10-1 00 fold
lower than after application.
Comnarisons with Exnosure Limit Standards: The first three methods showed mean exposures of
1.2-1.7 jig/day (0.1-0.2 |ig/kg/day for a 10 kg child), with an upper range estimate of 6-7 ng/day.
For comparison, the World Health Organization's Acceptable Daily Intake (ADI) for 2,4-D is
300 ng/kg/day and the U.S. EPA Integrated Risk Information System (IRIS) Reference dose
(Rfd) is 10 ng/kg/day (26). Our calculated exposures, then, are less than the RfD, the daily
exposure without risk over a lifetime, in both pre-and post-application times. However, our
hypothetical NDI exposures may approach the RfD shortly after application, if contact with
smooth surfaces is shown to follow patterns established in preliminary laboratory tests. The
exposures due to contact with smooth surfaces, then, is an area that will require greater study
before the value of these estimates can be established.
57
-------
Table 15. Estimated Pre-Application 2,4-D Daily Exposure (Non-Dietary and Inhalation)
for One-Yr Old Child in Different Home Environments: Comparison between
Three Methods for Estimating Non-Dietary Ingestion Component
Estimated Combined Inhalation and Non-Dietary Ingestion
Pre-Application Exposure (jig/day) based on:
PUF Roller"
100 mg Dust
Activity
Contact with
Home Activity Descriptors
Ingestionb
Descriptors Smooth Surface"
HiP HiC Sd
0.02
0.08
NAe
0.19
LoP HiC S
0.02
0.03
NA
0.14
LoP ModC S
0.01
0.07
NA
0.10
LoP HiC NS
0.01
0.05
NA
0.06
LoP LoC NS
0.01
0.06
NA
0.10
a) See footnotes a and b, Table 11; with exception that surface dislodgeable residue loading
estimated from 2,4-D carpet dust loading (xO.Ol).
b) See footnotes a and c, Table 11.
c) See footnotes a and d, Table 11; with exception that table surface loading estimated from
2,4-D carpet dust loading (xO.l).
d) NA= not applicable; calculation assumes 2,4-D applied to lawn.
58
-------
References
(1) Savage, E.P.; Keefe, T.J.; Wheeler, H.W.; Mounce, L.M.; Helwic, L.; Applehaus, F.;
Goes, E.; Goes, T.; Mihlan, G.; Rench, J.; Taylor, DK; Arch Environ Health 1981, 36.
304-309.
(2) Whitmore, R.W.; Kelly, J.E.; Reading, P.L.; National Home and Garden Pesticide Use
Survey, Final Report, Vol 1; Report No. RTI/5100/17-01F, prepared for the U.S.
Environmental Protection Agency by Research Triangle Institute, Research Triangle
Park, NC, March 1992.
(3) Lewis, R.G.; Fortmann, R.C; Camann, DE; Arch Environ Contamin Toxicol 1994, 26.
37-46.
(4) 'Whitmore, R.W.; Immerman, F.W.; Camann, D.E.; Bond, A.E.; Lewis, R.G.; Schaum,
J.L.; Arch Environ Contamin Toxicol 1994, 26, 47-59.
(5) Richter, E.D.; Kowalski, M.; Leventhal, A.; Grauer, F.; Marzouk, J.; Brenner, S.;
Shkolnik, I.; Lerman, S.; Zahavi, H.; Bashari, A.; Peretz, A.; Kaplanski, H.; Gruener, N.;
Ishai, B.P.; Arch Environ Health 1992, 47, 135-138.
(6) Mukejee, S.; Ellenson, W.T.; Lewis, R.G.; Stevens, R.K.; Somerville, M.C.; Shadwick,
D.S.; Willis, R.D.; Environ Int 1997. 23. 657-673.
(7) Anderson, D.J.; Hites, R.A.; Atmos Environ 1989, 23, 2063-2066.
59
-------
(8) Roinestad, K.S.; Louis, J.B.; Rosen, J.D.; JAOACInt 1993, 76, 1121-1 126.
(9) Simcox, N.J.; Fenske, R.A.; Wolz, S.A.; Lee, I-C.; Kalman, D.A.; Environ Health
Perspect 1995, 103. 1126-1 134.
(10) Nishioka, M.G.; Burkholder, H.M.; Brinkman, M.C.; Gordon, S.M.; Lewis, R.G.;
Environ Sci Tech 1996, 30, 3313-3320.
(11) U.S. Environmental Protection Agency; Air Concentrations and Inhalation Exposure to
Pesticides in the Agricultural Health Pilot Study; Report No. EPA/600/R-97/059;
Research Triangle Park, NC, June 1997.
(12) Maybank,J., Yoshida, K., Grover, R.; J Air Pollut Control Assoc 1978. 28. 1009-1014.
(13) Grover,R., Maybank, J., Yoshida, K.; Weed Sci 1972, 20, 320-324.
(14) Nash, R.G.; Chemosphere 1989, 18, 2363-2373.
(15) Glotfelty, D.E.; J Air Pollut Control Assoc 1978,28, 917-921.
(16) Nishioka, M.G.; Burkholder, H.M.; Brinkman, M.C.; Gordon, S.M.; "Simulation of
Track-In of Lawn-Applied Pesticides from Turf to Home: Comparison of Dislodgeable
Turf Residues with Carpet Dust and Carpet Surface Residues"; U.S. Environmental
Protection Agency Report No. EPA/600/R-97/108; Research Triangle Park, N.C.; 1997
(NTIS Accession No. PB98-103120).
(17) Zirschky, J.; J Environ Engineering 1996. 122. 430-436.
60
-------
(18) Exposure Factors Handbook; U.S. Environmental Protection Agency; Publication No.
EPA/600/P-95/002Ba; 1996.
(19) Dietz, R.N., Cote, E.A.; Environ International 1982,8, 419-433.
(20) Rousseau, R.W.; Ferreli, J.K.; Macnie, R.N.; "Perspiration Poisoning of Protective
Clothing Materials-Part IV"; Technical Report: Natick/TR/84/009L, AD-B088-681; U.S.
Army Natick Research, Development and Engineering Center, Natick, MA; 1983.
(21) Thatcher, T.L. and Layton, D.W.; atmospheric environment 1995, 29, 1487-1497.
(22) Rodes, C.E.; preliminary report to U.S. EPA on Contract No. 68-D5-0040 WA-023;
March 1998.
(23) Roberts, J.W.; Budd, W.T.; Ruby, M.G.; Bond, A.E.; Lewis, R.G.; Wiener, R.W.;
Camann, D.E.; J Exp Anal Environ Epi 1991; I, 143-155.
(24) Harris, S.A, Solomon, K.R.; J Tox Environ Health 1992, 36, 233-240.
(25) Freeman, N.; personal communication; Feb 1998.
(26) Pesticide Profiles: Toxicity, Environmental Impact, and Fate; ed. M.A. Kamrin, Lewis
Publishers, Boca Raton, 1997.
61
-------
I
APPENDIX A
-------
Table 1. Concentration of 2,4-D in Air During Application (Cascade Impactor), Yrl
Table 2. Concentration of 2,4-D in Air on Day 1 and Day 3 (URG Sampler), Yr 1
Table 3. Concentration of 2,4-D in Air by Particle Size Range (URG Sampler), Yrl
Table 4. Recovery of 3,4-D in Air Samples, Yrl
Table 5. Surface Loading of 2,4-D on Sills and Tables, ug/m2, Yrl
Table 6. Surface Loading by Traffic Pattern: 2,4-D and Dicamba in Floor Dust with HVS3
Collection, Yrl
Table 7. Surface Loading by Traffic Pattern: 2,4-D on Bare Floors by Wipe, Yrl
Table 8. Modelling Surface Loading of 2,4-D on Bare Floors, Yrl
Table 9. Comparison of Surface Loading of 2,4-D from Collection by PUF Roller and HVS3 on
Living Room Carpet, Yrl
Table 10. Comparison of Air Exchange Rates and 2,4-D Deposition Coupon Levels, Yrl
Table 11. QA/QC Samples for Air Samples, Yrl
Table 12. QA/QC Samples for Dust Samples (Floors/Sills/Tables), Yrl
Table 13. Calibration Ranges Used by Media/Sample Type, Yrl
Table 14. Air Volumes Sampled, Yrl
Table 15. Surface Areas Wiped or Vacuumed and Dust Quantity Collected, Yrl
Table 16. Comparison of Dust Loading, 2,4-D Loading, and 2,4-D Dust Concentration, Yrl
Table 17. Designation of Hours by Activity Patterns, Yrl
Home Schematics and Sampling Locations
-------
Table 1. Concentration of 2,4-D in Air During Application (Cascade Impactor), Yrl
Concentration of 2,4-D by Particle Size, ng/m3 Cone, by PM, ng/m3
Home <1 nm 1-2 |im 2-8 nm >8 fim PM2.5* PM10*
BY 2.15 2.31 4.59 4.7 4.46 9.05
Rn 2.16 2.64 5.25 3.44 4.80 10.05
Zm 1.86 2.78 13.06 3.95 4.64 17.7
SC 1.68 1.39 2.77 2.15 3.07 5.84
Ad 1.97 0.81 6.52 0.79 2.78 9.30
Rr 1.54 1.39 1.68 5.91 2.93 4.61
Lb 1.68 2.72 6.60 5.68 4.40 11.00
Average 1.86 2.01 5.78 3.80 3.87 9.65
StdDev 0.24 0.80 3.69 1.86 0.89 4.23
Range 1.54-2.16 0.80-2.78 1.68-13.06 0.79-5.91 2.78-4.80 4.61-17.7
* PM2.5= sum of concentrations (<1 |am + 1-2 pm)
* PM10= sum of concentrations (<1 nm + 1-2 |^m + 2-8 ^m)
A-l
-------
Table 2. Concentration of 2,4-D in Air on Dayl and Day 3 (URG Sampler), Yrl
Concentration of 2,4-D by Particle Size, ng/m3 Cone, by PM. ng/m3
Home 1 <1 nm <2.5 |im <10 nm TSP PM2.5 PM10
By-dayl 1.52 1.52 6.04 9.47 1.52 6.04
By-day 3 1.93 loss 10.75 17.16 1.93 10.75
Rn-dayl 1.39 1.96 3.29 4.94 1.96 3.29
Rn- day 3 1.70 1.34* 2.88 3.48 1.70 2.88
Zm-dayl 1.51 1.55 4.48 5.46 1.55 4.48
Zm- day 3 nd 0.17 1.27 4.03 0.17 1.27
Sc-day 1 0.34 1.46 lab loss 1.39 1.46 lab loss
Sc- day 3 nd nd nd nd 0.00 0.00
Ad-day I 0.64 0.51* 1.42 2.14 0.64 1.42
Ad- day 3 nd 0.00 0.24 0.24 0.00 0.24
Rr-dayl 0.98 1,11 2.42 3.91 1.11 2.42
Rr- day 3 1.68 1.32* 4.63 6.12 1.68 4.63
Lb-dayl 0.36 nd* 0.37 1.48 0.36 0.37
Lb-day 3 nd nd 0.69 1.15 0.00 0.69
Average-day 1
Average-day3
Range-day 1
Range-day 3
0.96 ±0.52
0.76 ±0.95
0.34 -1.52
0.00-1.93
1.16 ±0.68
0.41 • 0.63
0.00-1.96
0.00-1.34
3.00 ±2.06
2.92 ±3.82
0.37 -6.04
0.00 -10.75
4.11 • 2.87
4.60 h5.97
1.39 -9.47
0.00-17.16
1.23 ±0.56
0.79 ±0.92
0.36 -1.96
0.00-1.93
3.00 ±2.06
2 92 h3.82
0.37 -6.04
0.00 -10.75
* 2,4-D concentration in 2.5 pm fraction is less than the concentration in the 1.0 nm fraction; cause unknown
A-2
-------
Table 3. Concentration of 2,4-D in Air by Particle Size Range (URG Sampler), Yrl
Cone of 2,4-D by Particle Size Range, ng/m3
Cone, by PM, ng/m3
Home
<1 urn 1-2.5 nm 2.5-10 nm >10 |im PM2.5
PM10
By- day 1
By- day 3
1.52
1.93
0.00
0.00
4.52
8.82
3.43
6.41
1.52
1.93
6.04
10.75
Rn- day 1
Rn- day 3
1.39
1.70
0.57
0.00
1.33
1.54
1.66
0.60
1.96
1.70
3.29
2.88
Zm- day 1
Zm- day 3
1.51
0.00
0.03
0.17
2.93
1.11
0.98
2.75
1.55
0.17
4.48
1.27
Sc- day 1
Sc- day 3
0.34
0.00
1.13
0.00
lab loss
0.00
0.00
0.00
1.46
c-.oo
lab loss
0.00
Ad- day 1
Ad- day 3
0.64
0.00
00.00
0.00
0.91
0.24
0.72
0.00
0.64
0.00
1.42
0.24
Rr- day 1
Rr- day 3
0.98
1.68
0.13
0.00
1.31
3.31
1.48
1.49
1.11
1.68
2.42
4.63
Lb-day 1
Lb- day 3
0.36
0.00
0.00
0.00
0.37
0.69
1.11
0.45
0 36
0.00
0.37
0.69
Average-day 1
Average-day3
Range- hay 1
Range- day 3
0.96 k0.52
0.76 • 0.95
034 -1.52
0.00-1.93
0.27 • 043
0.02 ±0.06
0.00 -1.13
0.00 -0.17
1.90 ±1.54
2.24 ±3.10
0.37 -4.52
0 00 -8.82
1.56 ±0.98
1 67 ±2.30
0.72 -3.43
0 00 -6.41
1.23 ±0.56
0.79 ±0.92
0.36 -1.96
0 00 -1.93
3.00 ±2.06
2 92 ±3.82
0.37 -6 04
0.00 -10.75
A-3
-------
Table 4. Recovery of 3,4-D in Air Samples, Yrl
Time/home Recovery of 3,4-D. in Particle Size Sample, % ave 3,4-D
Application
<1 jim
1-2 Jim
2-8 Jim
>8 fin
BY
111
95
90
94
Rn
116
104
99
94
Zm
115
95
98
101
SC
109
107
98
92
Ad
103
104
112
107
Rr
107
101
98
32
Lb
100
90
88
. 78
URG-day 1
<1 |im
<2.5 |im
<10 |im
TSP
BY
81
87
80
80
Rn
80
88
85
82
Zm
82
83
83
85
SC
112
90
90
110
Ad
94
91
94
95
Rr
77
82
79
77
Lb
106
62
60
102
URG-day 3
<1 nm
<2.5' |im
<10 jim
TSP
BY
99
94
91
94
Rn
90
85
113
90
Zm
102
69
66
63
SC
131
123
130
131
Ad
109
109
104
100
Rr
89
95
105
87
Lb
146
142
140
147
A-4
-------
Table 5. Surface Loading of 2,4-D on Sills and Tables, ug/m2, Yr 1
Home Time Surface Loading of 2,4-D on Sill or Table, txg/m2 recovery
By-Sill
Liv
Kit
Bed-back
Bed-side
3,4-D,
pre-2,4-D
0.88
nd
0.90
nd
3,4-D, %
47
83
100
88
post-2,4-D
22.2
10.5
4.83
5.90
3,4-D, %
52
70
72
69
By-Table
Liv
Kit
Din
Bed
pre-2,4-D
nd
nd
nd
nd
3,4-D, %
86
88
91
90
post-2,4-D
24.0
21.1
27.3
6.41
3,4-D, %
66
77
68
73
77 ± 14
Rn-Sill
Liv
Kit
Din
Bed
pre-2,4-D
nd
nd
nd
nd
3,4-D, %
78
93
88
92
post-2,4-D
3.82
3.01
2.16
1.08
3,4-D, %
64
70
62
61
Rn-Table
Liv
Kit
Din
Bed
pre-2,4-D
nd
nd
nd
nd
3,4-D, %
94
96
102
88
post-2,4-D
2.69
2.49
3.11
1.55
3,4-D, %
81
91
76
72
83 ± 14
A-5
-------
Table 5. Surface Loading of 2,4-D on Sills and Tables, ug/m2, Yr 1 (Continued)
Home Time Surface Loading of 2,4-D on Sill or Table, iig/m2 recovery
Zm-Sill
Kit
Liv
'Din
Bed
3,4-D
pre-2,4-D
nd
nd
nd
nd
3,4-D, %
121
101
102
120
post-2,4-D
3.36
2.71
2.55
1.72
3,4-D, %
73
59
55
68
Zm-Table
Kit
Liv
Din
Bed
pre-2,4-D
nd
nd
nd
nd
3,4-D, %
161
114
154
157
post-2,4-D
4.04
5.05
3.93
2.08
3,4-D, %
87
100
77
80
104 ±34
SC-Sill
Din
Liv
Bed-Child
Bed-Adult
pre-2,4-D
0.78
0.71
nd
1.15
3,4-D, %
36
62
92
89
post-2,4-D
1.97
1.80
0.92
0.56
3,4-D, %
44
50
76
80
SC-Table
Liv
Hall
Din
Bed
pre-2,4-D
nd
nd
nd
nd
3,4-D, %
114
115
101
110
post-2,4-D
1.74
1.98
1.39
2.00
3,4-D, %
• 82
79
86
79
82 ±23
A-6
-------
Table 5. Surface Loading of 2,4-D on Sills and Tables, ug/m2, Yr 1 (Continued)
Home Time Surface Loading of 2,4-D on Sill or Table, iig/m2 recovery
Ad-Sill
Liv
Kit
Din
Bed
3,4-D
pre-2,4-D
0.40
lab loss
0.52
nd
3,4-D, %
69
77
78
post-2,4-D
0.77
0.65
0.53
0.51
3,4-D, %
75
84
74
74
Ad-Table
Fam
Liv
Din
Bed
pre-2,4-D
nd
nd
0.82
nd
3,4-D, %
70
78
83
75
post-2,4-D
2.18
0.53
0.48
0.29
3,4-D, %
84
106
105
111
82 ± 17
Rr-Sill
Liv
Kit
Din
Bed
pre-2,4-D
nd
nd
nd
lab loss
3,4-D, %
113
70
109
-
post-2,4-D
0.93
1.43
1.08
1.37
3,4-D, %
63
62
64
48
Rr-Table
Liv
Kit
Din
Bed
pre-2,4-D
nd
0.52
nd
0.51 '
3,4-D, %
127
67
121
60
post-2,4-D
4.76
3.08
3.30
1.28
3,4-D, %
79
80
75
99
86 ±26
A-7
-------
I
Table 5. Surface Loading of 2,4-D on Sills and Tables, ug/m2, Yr 1 (Continued)
Home Time Surface Loading of 2,4-D on Sill or Table, |ig/m2 recovery
Lb-Sill
Liv
Kit
Fam
Bed
3,4-D
pre-2,4-D
nd
nd
nd
nd
3,4-D, %
58
100
55
62
post-2,4-D
0.39
1.72
1.89
1.83
3,4-D, %
76
75
71
68
Lb-Table
Liv
Din
Fam
Bed
pre-2,4-D
nd
nd
nd
0.50
3,4-D, %
53
54
59
58
post-2,4-D
1.66
3.45
0.45
1.01
3,4-D, %
81
59
76
76
69 ± 13
A-8
-------
I
Table 6. Surface Loading by Traffic Pattern: 2,4-D and Dicamba in Floor Dust with HVS3
Collection, Yrl
Home (type)/Time Surface Loading of Analyte in Dust, |ig/m2 recovery
BY
Entry
Liv
Din
Kit*
Bed
3,4-D
pre-dicamba
0.05
0.05
0.04
co.01
0.14
pre-2,4-D
0.54
0.64
0.39
0.03
1.07
3,4-D rec, %
97
108
98
90
107
post-dicamba
7.20
10.4
4.23
0.15
2.03
post-2,4-D
228
188
117
1.60
24.6
3,4-D rec, %
99
83
101
98
73
95 ±11
Rn
Kit*
Entry*
Din*
Liv
Bed
pre-dicamba
0.01
0.43
0.03
0.08
0.19
pre-2,4-D
0.08
5.74
0.30
0.48
2.22
3,4-D rec, %
118
58
75
77
112
post-dicamba
0.05
0.27
0.13
3.77
1.11
post-2,4-D
0.71'
3.13
1.65
70.0
26.6
3,4-D rec, %
92
90
100
71
69
93 ± 19
Zm
Entry
Kit
Liv
Din
Bed
pre-dicamba
0.07
0.05
0.16
0.04
0.03
pre-2,4-D
1.17
1.06
0.35
0.44
0.19
3,4-D rec, %
65
40
79
57
121
post-dicamba
2.32
1.06
0.59
0.64
0.31
post-2,4-D
73.8
34.9
13.0
11.6
5.25
3,4-D rec, %
83
83
119
89
106
84 ±26
A-9
-------
Table 6. Surface Loading by Traffic Pattern: 2,4-D and Dicamba in Floor Dust with HVS3
Collection, Yrl (Continued)
Home Surface Loading of Analyte in Dust, ng/m2 recovery
sc
Entry
Din*
Kit*
Liv
Bed
3,4-D
pre-dicamba
0.04
0.01
co.01
0.16
0.10
pre-2,4-D
0.67
0.09
0.03
2.73
0.45
3,4-D rec, %
104
94
92
73
89
post-dicamba
2.53
0.06
0.02
1.56
0.84
post-2,4-D
17.4
0.66
0.25
12.7
4.51
3,4-D rec, %
88
91
91
101
108
93 ± 10
Ad
Entry
Fam
Kit
Din*
Bed
pre-dicamba
0.05
0.05
0.04
0.03
0.02
pre-2,4-D
0.82
0.82
0.95
0.61
0.24
3,4-D rec, %
35
37
47
52
26
39 ± 10
post-dicamba
0.26
0.13
0.11
nd
0.01
post-2,4-D
3.06
'1.39
1.39
0.02
0.10
3,4-D rec, %
89
92
129
114
113
107 ± 17
Rr
Entry*
Din*
Kit*
Liv
Bed
pre-dicamba
0.06
co.01
co.01
0.02
0.03
pre-2,4-D
0.81
0.08
0.05
0.21
0.54
3,4-D rec, %
99
98
101
100
101
post-dicamba
0.11
0.05
0.02
0.44
0.28
post-2,4-D
1.47
0.59
0.26
4.97
3.63
3,4-D rec, %
93
94
102
86
143
99 ±11
#- suspect spiking error
A-10
-------
I
Table 6. Surface Loading by Traffic Pattern: 2,4-D and Dicamba in Floor Dust with HVS3
Collection, Yrl (Continued)
Home Surface Loading of Analyte in Dust, |ig/m2 recovery
Lb
Ent/Kit*
Din
Liv
Bed
Fam
3,4-D
pre-dicamba
co.01
0.03
0.03
0.04
0.02
pre-2,4-D
0.07
0.28
0.34
0.62
0.23
3,4-D rec, %
93
97
98
47
114
post-dicamba
0.01
0.17
0.17
0.46
0.09
post-2,4-D
0.19
1.90
1.92
4.02
1.16
3,4-D rec, %
95
94
104
79
108
93 ±19
A-11
-------
Table 7. Surface Loading by Traffic Pattern: 2,4-D on Bare Floors by Wipe, Yrl
Home/ Time Surface Loading of Analyte in Dust, |ig/m2 recovery
BY
Entry
Liv
Din
Kit* Bed
3,4-D
pre-2,4-D
NS
post-2,4-D
22.7
3,4-D, %
55
55
Rn
Kit*
Entry*
Din*
Liv Bed
pre-2,4-D
0.32
0.32
0.34
3,4-D, %
84
74
66
post-2,4-D
9.17
2.50
5.09
3,4-D, %
71
65
73
72 ±7
Ad
Kit
Liv
Entry
Din* Bed
pre-2,4-D
0.55
3,4-D, %
74
post-2,4-D
lab loss
3,4-D, %
¦lab loss
7 4
Rr
Entry*
Din*
Kit*
Liv Bed
pre-2,4-D
NS
NS
NS
post-2,4-D
1.58
0.67
0.56
3,4-D, %
77
88
77
81 ±6
NS- not sampled
A-12
-------
Table 8. Modelling Surface Loading of 2,4-D on Bare Floors, Yrl
Pre-Application Post-Application
Home
Room
Flooring
Wipe
HVS3
Wipe
HVS3
BY
Kit
s s
(0.09)*
0.03
22.7
1.6
Rn
Kit
s s
0.32
0.08
9.17
0.71
Entry
RS
0.32
5.74
2.50
3.13
Din
1/2 RS
0.34
0.30
5.09
1.65
Zm
none
SC
Kit
s s
(0.09)
0.03
(2.50)
0.25
Din
SS
(0.27)
0.09
(6.60)
0.66
Ad
Din
1/2 RS
0.55
0.61
(0.06)
0.02
Rr
Entry
RN
(0.08)
0.81
1.58
1.47
Din
S N
(0.08)
0.08
0.67
0.59
Kit
SN
(0.05)
0.05
0.56
0.26
Lb
Kit
SN
(0.07)
0.07
(0.19)
(0.19)
pre-application post-application
wipe/vac ratio wipe/vac ratio
SS- smooth floor/shoes worn 3 10
1/2RS-slightly rough/shoes worn -equal 3
RS- rough surface/shoes worn 0.1 ~ equal
RN-rough surface/no shoes 0.1 ~ equal
SN-smooth floor/no shoes ~ equal ~ equal
* estimated with respect to HVS3 data and above listed ratios
A-13
-------
Table 9. Comparison of Surface Loading of 2,4-D from Collection by PUF Roller and HVS3 on
Living Room Carpet, Yrl
Surface Loading of 2,4-D by PUF Roller and HVS3 Collection, Hg/m2
Pre-Application Sampling Post-Application Sampling
Home PUF Roller 3,4-D,%* HVS3 PUF Roller 3,4-D,%* HVs3
BY 0.01 93 0.64 1.69 95 188
Rn 0.06 89 0.48 0.38 93 70
Zm co.01 101 0.35 0.10 107 13
SC 0.03 90 0.67 0.14 108 17.4
Ad co.01 103 0.82 0.01 52 3.06
Rr 0.13 90 0.21 0.09 118 4.97
Lb co.01 149 0.34 co.01 102 1.92
H V S 3 %sn$13,4-D HVS3 vs PR ave 3,4-D
1^= 0.29 102 ±21 r*= 0.98 96 ±21
* recovery of 3,4-D from analysis of PUF Roller sleeve
A-14
-------
Table 10. Comparison of Air Exchange Rates and 2,4-D Deposition Coupon Levels, Yr 1
Infiltration Air Exchange 2,4-D Deposition, mg/m2*
Rate Rate Coupon Placement with respect to
Home
Home
nrVhr
L/hr
Coupon 1
Coupon 2
Coupon 3
average
BY
247
0.5
27.7
48.2
51.4
42.5
NW
S
NE
Rn
289
0.6
'54.9
42.6
54.0
50.5
SE
SW
N
Zm
407
0.7
18.0
19.1
20.5
19.2
W
S
E
SC
249
0.6
53.3
72.9
40.2
55.5
NW
SW
E
Ad
300
0.6
4.7
4.3
18.8
9.2
NW
SW
E
Rr
254
0.6
8.2
11.0
72.6
30.6
SE
W
NE
Lb
127
0.3
40.1
251
183
158
N
SW
SE
* Desired application rate= 84 mg/m2
A-15
-------
Table 11. QA/QC Samples for Air Samples, Yrl
Medium QA/QC Amount of Analyte: Average:
Type Level or Recovery of 2,4-D ng or %
Recovery of 3,4-D, % %
Equivalent
Air Cone,
ng/m3
URG-filter field blank 2,4-D, ng: 7.3, 4.3, 5.4, 7.7 6.1 ± 1.5
3,4-D, %: 92, 95, 96, 93 94 ±2
1.1
(100 ng)*
lab blank 2,4-D, ng: 4.7, 3.0, 0.9
3,4-D, %: 91, 110, 115
2.9 ± 1.9
105 ± 13
0.5
(100 ng)*
solvent blank 2,4-D, ng: 0.0
3,4-D, %: 87
0.0
87
0.0
(100 ng)*
field spike 2,4-D, %: 80, 74
3,4-D, %: 93, 94
77 ±3
94 ±1
17.4
(100 ng)*
lab spike with 2,4-D, %: 85, 74, 77
storage 3,4-D, %: 90, 74, NS
79 ±6
82 ±8
17.4
(100 ng)*
solvent spike 2,4-D, %: 89
3,4-D, %: 75
89
75
17.4
(100 ng)*
URG-PUP field blank 2,4-D: 13.4, 10.5, 13.9, 13.5
3,4-D: 97, 95, 103, 83
12.8 ±1.6 2.2
95 ±8 (100 ng)*
lab blank 2,4-D:9.5,30.6,8.9,10.4,10.3 9.8 ± 0.7
3,4-D: 96, 93,101,97, 100 97 ± 3
1.7
(100 ng)*
solvent blank 2,4-D, ng: 13.8, 19.1, 12.7 15.2 ±3.4
3,4-D, %: 85, 80, 98 88 ± 9
2.6
(100 ng)*
* ng quantity of 3,4-D spiked; NS- not spiked
A-16
-------
Table 11. QA/QC Samples for Air Samples, Yrl (Continued)
Medium
QA/QC
Type
Amount of Analyte:
Level or Recovery of 2,4-D
Recovery of 3,4-D, %
Average:
ng or %
%
Equivalent
Air Cone,
ng/m3
URG-PUP
field spike
2,4-D, %: 80
3,4-D, %: 52
80
52
17.4
(100 ng)*
lab spike
2,4-D, %: 90, 92, 27
3,4-D, %: 93, 82, 101
91 ± 1
92 ± 10
17.4
(100 ng)*
lab spike with
storage
2,4-D, %: 85, 85, 85
3,4-D, %: 99,100, 99
85 ±0
99 ±1
17.4
(100 ng)*
solvent spike
2,4-D, %: 86, 99
3,4-D, %: NS, NS
93 ±6
NS
17.4
(NS)*
Caslmp-
plate
field blank
2,4-D, ng: 8.66, 6.35,5.15
3,4-D, %: 101,99, 109
6.7 ± 1.8
103 ±5
4.5
(100 ng)*
lab blank
2,4-D, ng: 11.29, 9.16
3,4-D,%: 104,98
10.2 ±1.0
101 ±3
6.8
(100 ng)*
Caslmp-
filter
field blank
2,4-D, ng: 5.66
3,4-D,%: 103
5.7
103
3.8
(100 ng)*
A-17
-------
Table 12. QA/QC Samples for Dust Samples (Floors/Sills/Tables), Yrl
QA/QC Type:
Home-Application
Period
Total 2,4-D
measured, ng
3,4-D Recovery, %
(100 ng spike)
Equivalent 2,4-D
loading, ^m2
Wipe Field Blank
(table loading)
By: pre-appl
36.0
93
0.42
By: post-appl
21.5
78
0.25
Rn: pre-appl
24.9
109
0.29
Rn: post-appl
32.8
83
0.38
Zm: pre-appl
22.9
143
0.27
Zm: post-appl
21.3
93
0.25
Sc: pre-appl
36.0
93
0.42
Sc: post-appl
13.2
95
0.15
Ad: pre-appl
40.6
81
0.48
Ad: post-appl
20.5
113
0.24
Rr: pre-appl
12.1
134
0.14
Rr: post-appl
23.8
94
0.28
Lb: pre-appl
24.9
68
0.29
Lb: post-appl
19.4
88
0.23
average
25 ± 8.5
98 ±21
0.29 ±0.10
PUF Roller- blank
5.5
102
0.010 (floor loading)
Dust-solvent blank
9.7
79
0.005 (floor loading)
12.9
NS
0.006 (floor loading)
12.0
NS
0.006 (floor loading)
19.0
157
0.010 (floor loading)
8.7
NS
0.004 (floor loading)
177
94
0.089 (floor loading)
54
95
0.027 (floor loading)
average
19.4 ± 17.3
106 ±35
0.010 ±0.009
A-18
-------
Table 12. QA/QC Samples for Dust Samples (Floors/Sills/Tables), Yrl (Continued)
QA/QC Type:
Home-Application
Period
2,4-D Recovery,%
(100 ng spike)
3,4-D Recovery, %
(100 ng spike)
Equivalent 2,4-D
loading, ng/m2
Wipe Field Spike
By: pre-appl
By: post-appl
Rn: pre-appl
Rn: post-appl
Zm: pre-appl
Zm: post-appl
Sc: post-appl
Ad: pre-appl
Ad: post-appl
Rr: post-appl
Lb: post-appl
average
122
111
43
101
63
103
74
140
92
88
79
92 ±27
122
87
99
80
87
73
47
76
84
73
88
83 ± 18
(table loading)
1.17
1.17
1.17
1.17
1.17
1.17
1.17
1.17
1.17
1.17
1.17
1.17
PUF Roller- spike
Dust-solvent spike
average
71
113(2 ng)
75 (0-5 Hg)
88 (2 ^g)
89 (2 ^g)
91 ± 16
104
88 (0.5 ng)
78 (0.5 ng)
89 (0.5 ng)
93 (0.5 ng)
87 ±6
0.21 (floor)
1 .0 (floor)
0.25 (floor)
1.0 (floor)
1 .0 (floor)
1 .0 (floor)
A-19
-------
Table 13. Calibration Ranges Used by Media/Sample Type, Yrl
Air Samples (pre- and post-application)
URG Filter, URG PUF, Cascade Impactor
Solution Concentration of Analyte in Standard Solution,
Name
Hg/mL
2,4-D
3,4-D (SRS)
2,6-D (IS)
Air 100
0.100
0.100 (100% rec)
0.100
Air 50
0.050
0.075 (75% rec)
0.100
Air25
0.025
0.050 (50% rec)
0.100
Air 10
0.010
0.025 (25% rec)
0.100
AirO
0.000
0.000 (0% rec)
0.100
Wipe Samples (pre-application)
Table, Sill, Floor
Solution
Name
Concentration of Analyte in Standard Solution,
Hg/mL
2,4-D
.3,4-D (SRS)
2,6-D (IS)
Wipe 100
0.100
0.100 (100% rec)
0.100
Wipe 50
0.050
0.050 (50% rec)
0.100
Wipe 25 '
0.025
'0.025 (25% rec)
0.100
Wipe 10
0.010
0.010 (10% rec)
0.100
Wipe 5
0.005
0.005 (5% rec)
0.100
Wipe 0
0.000
0.000 (0%> rec)
0.100
A-20
-------
Table 13. Calibration Ranges Used by Media/Sample Type, Yrl (Continued)
Wipe Samples (post-application)
Table, Sill, Floor
Solution Concentration of Analyte in Standard Solution,
Name
jig/mL
2,4-D
3,4-D (SRS)
2,6-D (IS)
Wipe 1000
1 .000
0.100 (100% rec)
0.100
Wipe 500
0.500
0.050 (50% rec)
0.100
Wipe 200
0.200
0.020 (20% rec)
0.100
Wipe 100
0.100
0.010 (10% rec)
0.100
Wipe 50
0.050
0.050 (50% rec)
0.100
Wipe 20
0.020
0.020 (20% rec)
0.100
Wipe 10
0.010
0.010 (10% rec)
0.100
Wipe 0
0.000
0.000 (0% rec)
0.100
Floor Dust Samples (pre- and post-application)
HVS3-Collected Dust
Solution Concentration of Analyte in Standard Solution,
Name
(ig/mL
2,4-D
3,4-D (SRS)
2,6-D (IS)
Dust 2000
2.000
0.500 (100% rec)
0.500
Dust 1000
1 .000
0.375 (75% rec)
0.500
Dust 500
0.500
0.250 (50% rec)
0.500
Dust 200
0.200
0.125 (25% rec)
0.500
Dust 100
0.100
0.500 (100% rec)
0.500
Dust 0
0.000
0.000 (0% rec)
0.500
A-21
-------
I
Table 13. Calibration Ranges Used by Media/Sample Type, Yrl (Continued)
PUF Roller Samples (pre- and post-application)
Floor Dust Dislodgeable Residues
Solution
Name
Concentration of Analyte in Standard Solution,
Hg/mL
2,4-D
3,4-D (SRS)
2,6-D (IS)
PUF 100
0.100
0.100 (100% rec)
0.100
PUF 50
0.050
0.075 (75% rec)
0.100
PUF 20
0.020
0.050 (50% rec)
0.100
PUF 10
0.010
0.025 (25% rec)
0.100
PUF 0
0.000
0.000 (0% rec)
0.100
Lawn Coupons Samples ( post-application)
Application Deposition Coupons
Solution
Name
Concentration of Analyte in Standard Solution,
Hg/mL
2,4-D
3,4-D (SRS)
2,6-D (IS)
coup 2000
2.000
not added
0.500
coup 1000
1 .000
not added
0.500
coup 500
0.500
not added
0.500
coup 200
0.200
not added
0.500
coup 100
0.100
not added
0.500
Coup 0
0.000
not added
0.500
A-22
-------
Table 14. Air Volumes Sampled, Yrl
Total Air Volume Sampled in Particle Size Range, m3
Home: sample
<1 |im
<2.5 nm
<10 nm
TSP
By: pre-URG
6.01
5.85
5.56
5.78
post 1 -URG
5.80
5.83
5.74
5.81
post3-URG
5.85
SL
5.84
5.85
cascade impactor
1.50
1.50
1.50
1.50
Rn: pre-URG
5.69
5.70
5.67
5.55
postl-URG
5.42
5.42
5.66
5.50
post3-URG
5.75
5.73
5.78
5.78
cascade impactor
1.71
1.71
1.71
1.71
Zm: pre-URG
5.64
5.58
5.70
5.72
postl-URG
6.52
6.57
6.52
6.66
post3-URG
5.77
5.95
6.03
5.62
cascade impactor
2.93
2.93
2.93
2.93
Sc: pre-URG
5.78
5.84
5.82
5.73
postl-URG
6.15
6.01
SL
6.03
post3-URG
6.11
6.63
6.56
6.66
cascade impactor
1.50
1.50
1.50
1.50
A-23
-------
Table 14. Air Volumes Sampled, Yrl (Continued)
Total Air Volume Sampled by Particle Size Range, m3
Home: sample
<1 (im
<2.5
<10 nm
TSP
Ad: pre-URG
6.30
6.45
6.47
6.26
post 1 -URG
5.96
6.09
6.12
7.27
post3-URG
5.75
5.88
5.80
5.38
cascade impactor
0.75
0.75
0.75
0.75
Rr: pre-URG
5.71
5.86
5.77
5.34
post 1 -URG
5.29
5.82
5.84
5.82
post3-URG
7.06
6.94
6.89
6.89
cascade impactor
1.66
1.66
1.66
1.66
Lb: pre-URG
5.82
5.82
5.82
5.82
post 1-URG
5.47
5.59
5.64
5.53
post3-URG
5.58
5.58
5.72
5.78
cascade impactor
1.50
1.50
1.50
1.50
A-24
-------
Table 15. Surface Areas Wiped or Vacuumed and Dust Quantity Collected, Yrl
Home
Floor Area Sampled,
m2
HVS3 Floor
Dust, g
Sill Area,
2
m
Table
Area, m2
Traffic
Density/Room
HVS3
Wipe PUF
Roller
pre-
appl
post-
appl
By: Entry
0.84
0.70
2.22
Liv
2.0
0.48
1.7
5.59
0.142
0.0854
Din
1.68
1.19
2.71
(0.094)
0.0854
Kit*
1.0
0.2
-
--
0.054
0.0854
Bed
1.68
2.71
4.79
0.045
0.0854
Rn: Kit*
2.0
0.2
--
--
0.0497
0.0854
Entry*
1.58
0.2
6.87
4.07
Din*
1.98
0.2
1.98
1.95
0.0697
0.0854
Liv
2.0
0.48
3.35
10.08
0.118
0.0854
Bed
1.76
5.15
4.37
0.059
0.0854
Zm: Entry
2.0
2.03
2.22
Kit
2.0
2.01
1.23
0.0948
0.0854
Liv
2.0
0.48
0.98
0.95
0.2748
0.0854
Din
2.0
1.26
1.16
0.2250
0.0854
Bed
1.0
0.86
0.67
0.0929
0.0854
SC: Din*
1.0
NT"
-
--
0.0939
0.0854
Kit*
2.0
NT
-
--
(0.1357)
0.0854
Entry
1.0
1.05
2.76
Liv
2.0
0.48
4.64
4.02
0.1056
0.0854
Bed
1.98
2.05
1.87
0.1275
0.0854
A-25
-------
Table 15. Surface Areas Wiped or Vacuumed and Dust Quantity Collected, Yrl (Continued)
Home
Floor Area Sampled,
2
m
HVS3 Floor
Dust, e
Sill Area,
__2
m
Table
Area, m2
Traffic
HVs3
wipe PUF
pre-
post-
Density/Room
Roller
appl
appl
Ad: Entry
1.6
3.10
1.33
Liv
2.0
0.48
3.28
0.56
(0.1839)
0.0854
Kit
0.54
1.43
0.17
0.1161
0.0854
Din*
2.0*
0.2
2.17
--
0.2371
0.0854
Bed
2.0
1.81
0.02
0.0919
0.0854
Rr: Entry*
1.98
0.2
4.40
1.57
Din*
1.5
0.2
--
0.1008
0.0854
Kit*
1.2
0.2
--
0.1008
0.0854
Liv
2.0
0.48
0.95
0.99
0.2015
0.0854
Bed
2.0
1.33
0.96
0.1234
0.0854
Lb: Entry*
1.4
NT
--
Kit
(1.7)b
0.64
0.39
0.0429
(0.0854)
Liv
2.0
0.48
1.11
0.48
0.1974
0.0854
Din
(2.0)
1.04
0.93
(0.0206)
(0.0854)
Bed
2.0
1.21
0.77
0.0426
0.0854
* bare floor
a) NT= not tested
b) floor listed here is a surrogate room for the one indicated
A-26
-------
Table 16. Comparison of Floor Dust Loading, 2,4-D Loading, and 2,4-D Dust Concentration,
Yrl
Home Home Location
BY
Entry
Liv
Din
Kit*
Bed
Pre
dust g/m2
0.70
0.85
0.60
NM\
1.36
2,4-D |ig/m2
0.54
0.64
0.39
0.03
1.07
2,4-D Hg/g
0.76
0.75
0.65
NM
0.79
Post
dust g/m2
2.64
2.80
1.61
NM
2.85
2,4-D fig/m2
228
188
117
1.60
24.6
2,4-D Hg/g
86.2
67.3
72.3
NM
8.63
Rn
Kit*
Entry*
Din*
Liv
Bed
Pre
dust g/m2
NM
4.35
1.00
1.68
2.93
2,4-D ng/m2
0.08
5.74
0.30
0.48
2.22
2,4-D Hg/g
NM
1.32
0.30
0.29
0.76
Post
dust g/m2
0.45
2.58
0.98
5.04
2.48
2,4-D ng/m2
0.71
3.13
1.65
70.0
26.6
2,4-D Hg/g
1.57
1.22
1.68
13.9
10.7
a) NM- not measured; dust quantitiy was not weighed as the amount was very small; dust was
extracted directly in the collection bottle
A-27
-------
Table 16. Comparison of Floor Dust Loading, 2,4-D Loading, and 2,4-D Dust Concentration,
Yrl (Continued)
Home Location
Zm
Entry
Kit
Liv
Din
Bed
Pre
dust g/m2
1.02
1.01
0.49
0.63
0.86
2,4-D ^g/m2
1.17
1.06
0.35
0.44
0.19
2,4-D Hg/g
1.15
1.05
0.72
0.70
0.22
Post
dust g/m2
1.11
0.62
0.48
0.58
0.67
2,4-D ng/m2
73.8
34.9
13.0
11.6
5.25
2,4-D Hg/g
66.5
56.7
27.5
20.0
7.84
SC
Entry
Din*
Kit*
Liv
Bed
Pre
dust g/m2
1.05
NM
NM
2.32
1.04
2,4-D jig/m2
0.67
0.09
0.03
2.73
0.45
2,4-D Hg/g
0.64
NM
NM
1.17
0.43
Post
dust g/m2
2.76
NM
NM
2.01
0.94
2,4-D |ig/m2
17.4
0.66
0.25
12.7
4.51
2,4-D *ig/g
6.30
NM
NM
6.30
4.77
A-28
-------
Table 16. Comparison of Floor Dust Loading, 2,4-D Loading, and 2,4-D Dust Concentration,
Yrl (Continued)
Home Location
Ad
Entry
Fam
Kit
Din*
Bed
Pre
dust g/m2
1.94
1.64
2.65
1 09
0.91
2,4-D jig/m2
0.82
0.82
0.95
0.61
0.24
2,4-D Hg/g
1.20
1.34
0.76
1 08
1.03
Post
dust g/m2
0.83
0.28
0.31
0.01
0.01
2,4-D |ag/m2
3.06
1.39
1.39
0.02
0.10
2,4-D Hg/g
3.68
4.97
4.41
3.08
10.2
Rr
Entry*
Din*
Kit*
Liv
Bed
Pre
dust g/m2
2.44
NM
NM
0.48
0.67
2,4-D ng/m2
0.81
0.08
0.05
0.21
0.54
2,4-D Hg/g
0.33
NM
NM
0.45
0.82
Post
dust g/m2
0.79
NM
NM
0.50
0.48
2,4-D ng/m2
1.47
0.59
0.26
4.97
3.63
2,4-D Hg/g
1.85
NM
NM
10.0
7.56
A-29
-------
Table 16. Comparison of Floor Dust Loading, 2,4-D Loading, and 2,4-D Dust Concentration,
Yrl (Continued)
Home Location
Lb
Ent/Kit*
Din
Liv
Bed
Fam
Pre
dust g/m2
NM
0.38
NM
0.61
NM
2,4-D V&W
0.07
0.28
0.34
0.62
0.23
2,4-D Hg/g
NM
0.75
NM
1.02
NM
Post dust g/m2
NM
0.23
0.24
0.39
0.47
2,4-D ng/m2
0.19
1.90
1.92
4.02
1.16
2,4-D Hg/g
NM
8.29
8.00
10.45
2.50
A-30
-------
Table 17. Designation of Homes by Activity Patterns, Yr 1
Activity Pattern Descriptor8
Child Activity
Shoes Worn Indoors
Pet Activity
Applicator Shoes
Worn Indoors
BY
HiC
S
HiP
As
Rn
HiC
S
LOP
As
Zm
ModC
s
LOP
NAs
SC
LoC
s
LOP
NAs
Ad
LoC
s
LOP
NAs
Rr
HiC
NS
LOP
NAs
Lb
LoC
NS
LOP
NAs
a) activity descriptors
HiC- high child activity
ModC- moderate child activity
LoC- low child activity
S- family outdoor shoes worn indoors
NS- family outdoor shoes not worn indoors
HiP- high pet activity
LoP- low pet activity
As- applicator's shoes worn indoors
NAs- applicator's shoes not worn indoors
A-3 1
-------
APPENDIX B
-------
Table 1. Concentration of 2,4-D in Air During Application (Cascade Impactor), Yr2
Table 2. Concentration of 2,4-D in Air on Day 1 and Day 3 (URG Sampler), Yr2
Table 3. Concentration of 2,4-D in Air by Particle Size Range (URG Sampler), Yr2
Table 4. Recovery of 3,4-D in Air Samples, Yr2
Table 5. Surface Loading of 2,4-D on Sills and Tables, Yr2
Table 6. Surface Loading by Traffic Pattern of 2,4-D and Dicamba in Floor Dust with HVS3
Collection from Carpets and Surface Wipe of Bare Floors, Yr2
Table 7. Surface Loading by Traffic Pattern: 2,4-D on Bare Floors by Wipe, Yr2
Table 8. Comparison of Surface Loading of 2,4-D from Collection by PUF Roller and HVS3
on Living Room Carpet, Yr2
Table 9. Comparison of Air Exchange Rates and 2,4-D Deposition Coupon Levels, Yr 2
Table 10. QA/QC Samples for Air Samples, Yr2
Table 11. QA/QC Samples for Dust Samples (Floors/Sills/Tables), Yr2
Table 12. Surface Areas Wiped or Vacuumed and Dust Quantity Collected, Yr2
Table 13. Comparison of Dust Loading, 2,4-D Loading and 2,4-D Dust Concentration, Yr2
Table 14. Designation of Homes by Activity Patterns, Yr2
Table 15. Air Volumes Sampled, Yr2
Home Schematics and Sampling Locations in Unoccupied Homes
-------
Table 1. Concentration of 2,4-D in Air During Application (Cascade Impactor), Yr2
Concentration of 2.4-D by Particle Size, ng/m3 Cone, by PM. ng/m3
Home <1 um 1-2 urn 2-8\im >8 um PM2.5* PM10*
BY 0.00 1.39 4.99 4.83 1.39 6.38
Zm 0.00 3.21 8.88 0.31 3.21 12.09
Mr 0.00 0.00 1.59 4.10 0.00 1.58
Lb 0.00 0.00 1.13 0.94 0.00 1.13
Nc 0.00 0.00 0.84 1.23 0.00 0.84
KY 0.00 0.74 2.17 0.00 0.74 2.91
Average 0.00 0.89 3.27 1.90 0.89 4.16
StdDev 0.00 1. 27 3.13 2.05 1.27 4.39
Range _ 0-0 q-3.21 0.84-8.88 0-4.83 0-3.21 0.84-12.1
* PM2.5= sum of concentrations (<1 Jim + 1-2 um)
* PM1 0= sum of concentrations (<1 |im + 1-2 fim + 2-8 |im)
B-l
-------
Table 2. Concentration of 2,4-D in Air on Day 1 and Day 3 (URG Sampler), Yr2
Concentration of 2,4-D by Particle Size, ng/m3 Cone, by PM. ng/m3
Home <1 urn <2.5 urn <10 um TSP PM2.5 PM10
By-day 1 1.90 2.17 2.13 4.21 2.17 2.13
By-day 3 2.78 2.47*a SL (2.47)b 6.81 2.47 (2.47)b
Zm-dayl 1.22 1.20* 1.88 2.28 1.20 1.88
Zm- day 3 1.58 1.26* 2.31 2.62 1.26 2.31
Rr-dayl 2.73 2.91 3.12 3.05 2.91 3.12
Rr- day 3 1.09 SL(1.09) 1.84 2.32 (1.09) 1.84
Lb-day 1 1.37 1.51 1.53 1.42 1.51 1.53
Lb-day 3 1.89 2.20 2.59 3.45 2.20 2.59
Nc- day 1 0.33 SL(0.33) 0.92 0.51 (0.33) 0.92
Nc- day 3 0.77 1.14 1.42 1.61 1.14 1.42
Ky-dayl 0.00 0.16 0.12 0.30 0.16 0.12
Ky- day 3 0.22 0.03* (0.22) 0.23 0.16 (0.22) 0.23
Average-day 1 1.26± 1.00 1.38±1.06 1.62±1.03 1.96±1.52 1.38±1.06 1.62±1.03
Average-day3 1.39±0.90 1.37±0.88 1.81±0.89 2.83±2.24 1.37±0.88 1.81±0.89
Range-day 1 0-2.73 0.16-2.91 0.12-3.12 0.30-4.21 0.16-2.91 0.12-3.12
Range-day 3 0.22-2.78 0.03-2.47 0.23-2.59 0.16-6.81 0.03-2.47 0.23-2.59
a) 2,4-D concentration in 2.5 um fraction is less than the concentration in the 1 .0 um fraction; cause unknown
b) pump failure occurred at this particle size; data from the next smaller particle size used instead
B-2
-------
Table 3. Concentration of 2,4-D in Air by Particle Size Range (URG Sampler), Yr2
Cone of 2.4-D by Particle Size Range, ng/m3 Cone, by PM. ng/m3
Home <1 um 1-2.5 um 2.5-10 um >10 um PM2.5 PM10
By- day 1
By- day 3
1.90
2.78
0.27
0.00
0.00
SL (0)a
2.08
(4.34)
2.17
2.47
2.13
(2.47)"
Zm- day 1
Zm- day 3
1.22
1.58
0.00
0.00
0.68
1.05
0.40
0.31
1.20
1.26
1.88
2.31
Rr- day 1
Rr- day 3
2.73
1.09
0.17
SL
0.21
(0.75)
0.00
0.48
2.91
(1.09)
3.12
1.84
Lb- day 1
Lb- day 3
1.37
1.89
0.14
0.31
0.03
0.39
0.00
0.86
1.51
2.20
1.53
2.59
Nc-.day 1
Nc- day 3
0.33
0.77
SL (0)
. 0.37
(0.59)
0.28
0.00
0.01
(0.33)
1.14
0.92
1.42
Ky- day 1
Ky- day 3
0.00
0.22
0.17
0.00
0.00
0.01
0.18
0.00
0.16
0.22
0.12
0.23
Average-day 1
Average-day3
Range- day 1
Range- day 3
1.26±1.00
1.39±0.90
0.00-2.73
0.22-2.78
0.13±0.11
0.14±0.19
0.00-0.17
0.00-0.3 1
0.25±0.31
0.41±0.41
0.00-0.68
0.19-1.05
0.44±0.82
1.03±1.65
0.00-2.08
0.00-4.34
1.38±1.06
1.4M0.82
0.16-2.91
0.03-2.47
1.62±1.03
1.81 zk0.89
0.12-3.12
0.23-2.59
a) see footnotes a) and b) of Table A-2
B-3
-------
Table 4. Recovery of 3,4-D in Air Samples, Yr2
Time/home Recovery of 3,4-D in Particle Size Sample, % average
Application
<1 nm
1-2 |im
2-8 fim
>8 (im
BY
115
83
62
67
Zm
78
60
65
67
Rr
60
94
67
62
Lb
113
103
96
102
NC
72
64
61
57
KY
102
94
80
102
80 ± 19
URG-day 1
<1 jim
<2.5
<10 |im
TSP
BY
99
89
103
97
Zm
87
94
95
98
Rr
63
86
82
89
Lb
87
85
94
97
NC
73
73
77
79
KY
86'
83
8 7
86
87 ± 9
URG-day. 3
<1
<2.5 (im
<10 nm
TSP
BY
77
69
75
77
Zm
74
85
83
85
Rr
89
78
90
87
Lb
87
85
94
97
Nc
84
79
81
83
KY
87
86
88
87
84 ± 6
B-4
-------
Table 5. Surface Loading of 2,4-D on Sills and Tables, Yr2
Home
Time
Surface Loading of 2,4-D on Sill or Table, |ig/m2
recovery
By-Sill
Liv
Kit
Bed-side
Bed-back
3,4-D
pre-2,4-D
nd
nd
NS
nd
3,4-D, %
88
92
NS
91
post-2,4-D
8.23
4.20
NS
2.64
3,4-D, %
60
77
NS
68
By-Table
Liv
Kit
Din
Bed
pre-2,4-D
nd
nd
NS
nd
3,4-D, %
88
105
NS
101
post-2,4-D
10.2
8.17
NS
3.24
3,4-D, %
80
71
NS
75
83 ± 14
Zm-Sill
Kit
Liv
Din
Bed
pre-2,4-D
1.77
0.46
NS
1.41
3,4-D, %
69
71
NS
69
post-2,4-D
1.81
1.23
NS
1.58
3,4-D, %
82
76
NS
79
Zm-Table
Kit
Liv
Din
Bed
pre-2,4-D
nd
nd
NS
nd
3,4-D, %
98
92
NS
84
post-2,4-D
2.39
2.54
NS
1.93
3,4-D, %
77
78
NS
73
79 ±9
B-5
-------
Table 5. Surface Loading of 2,4-D on Sills and Tables, Yr2 (Continued)
Home
Time
Surface Loading of 2,4-D on Sill or Table, ug/m
2
recovery
Rr-Sill
Kit
Din
Liv
Bed
3,4-D
pre-2,4-D
nd
NS
nd
nd
3,4-D, %
80
NS
88
79
post-2,4-D
3.90
NS
0.51
0.76
3,4-D, %
98
NS
77
82
Rr-Table
Kit
Din
Liv
Bed
pre-2,4-D
nd
NS
nd
nd
3,4-D, %
83
NS
83
89
post-2,4-D
2.69
NS
4.77
0.80
3,4-D, %
75
NS
84
75
83 ±7
Lb-Sill
Din
Liv
Kit
Bed
pre-2,4-D
nd
nd
NS
nd
3,4-D, %
101
103
NS
97
post-2,4-D
5.66
1.51
NS
0.45
3,4-D, %
79
81
NS
71
Lb-Table
Kit
Liv
Din
Bed
pre-2,4-D
nd
nd
NS
nd
3,4-D, %
119
113
NS
111
post-2,4-D
1.31
1.32
NS
0.89
3,4-D, %
94
110
NS
70
96 ± 17
B-6
-------
Table 5. Surface Loading of 2,4-D on Sills and Tables, Yr2 (Continued)
Home Time Surface Loading of 2,4-D on Sill or Table, ue/m2 recovery
Nc-Sill
Liv
Kit
Din
Bed
3,4-D
pre-2,4-D
NS
nd
NS
NS
3,4-D, %
NS
111
NS
NS
post-2,4-D
0.02
0.15
NS
nd
3,4-D, %
88
86
NS
103
NC-Table
Liv
Kit
Din
Bed
pre-2,4-D
NS
NS
NS
NS
3,4-D, %
NS
NS
NS
NS
post-2,4-D
0.44
0.77
NS
nd
3,4-D, %
96
99
NS
89
96 ±9
Ky-Sill
Liv
Kit
Din
Bed
pre-2,4-D
nd
NS
NS
NS
3,4-D, %
84
NS
NS
NS
post-2,4-D
nd
nd
NS
nd
3,4-D, %
78
73
'NS
75
Ky-Table
Liv
Kit
Din
Bed
pre-2,4-D
NS
NS
NS
NS
3,4-D, %
NS
NS
NS
NS
post-2,4-D
nd
nd
NS
nd
3,4-D, %
69
71
68
74 ±6
B-7
-------
Table 6. Surface Loading by Traffic Pattern of 2,4-D and Dicamba in Floor Dust with HVS3
Collection from Carpets and Surface Wipe of Bare Floors, Yr2
Home (type) Surface Loading; of Analyte in Dust, ug/m2 recovery
By
Entry
Liv
Din
Kit*
Bed
3,4-D
pre-dicamba
0.18
0.30
NS
nd
0.33
pre-2,4-D
3.16
4.92
NS
nd
4.29
3,4-D rec, %
80
82
NS
73
83
post-dicamba
4.49
4.02
NS
1.04
2.34
post-2,4-D
75.9
42.5
NS
7.85
31.9
3,4-D rec, %
88
95
NS
76
73
81 ±8
Zm
Entry
Kit
Liv
Din
Bed
pre-dicamba
0.01
nd
0.01
NS
0.02
pre-2,4-D
0.43
0.19
0.17
NS
0.22
3,4-D rec, %
83
79
72
NS
78
post-dicamba
1.74
0.42
0.36
NS
0.24
post-2,4-D
23.8
8.72
5.63
NS
5.21
3,4-D rec, %
85
73
92
NS
103
83 ± 10
Rr
Entry*
Din*
Kit*
Liv
Bed
pre-dicamba
0.05
NS
0.05
0.02
0.14
pre-2,4-D
0.68
NS
0.68
0.54
2.65
3,4-D rec, %
88
NS
77
122
94
post-dicamba
0.23
NS
0.15
1.05
0.30
post-2,4-D
2.64
NS
1.41
20.1
5.01
3,4-D rec, %
67
NS
65
85
93
86 ±18
B-8
-------
Table 6. Surface Loading by Traffic Pattern of 2,4-D and Dicamba in Floor Dust with HVS3
Collection from Carpets and Surface Wipe of Bare Floors, Yr2 (Continued)
Home Surface Loading of Analyte in Dust, ug/m2 recovery
Lb
Ent/Kit*
Din
Liv
Fam
Bed
3,4-D
pre-dicamba
nd
0.05
0.03
NS
0.06
pre-2,4-D
nd
1.02
0.65
NS
1.04
3,4-D rec, %
78
97
94
NS
91
post-dicamba
0.14
0.36
0.24
NS
0.36
post-2,4-D
2.22
6.50
4.62
NS
4.40
3,4-D rec, %
65
89
99
NS
92
88 ±11
Nc (unoccupied)
Entry*
Liv
Kit*
Din
Bed
pre-dicamba
'nd
0.02
nd
NS
NS
pre-2,4-D
nd
0.25
nd
NS
NS
3,4-D rec, %
84
115
92
NS
NS
post-dicamba
0.06
0.20
nd
NS
0.08
post-2,4-D
0.98
1.90
0.76
NS
0.81
3,4-D rec, %
8 1
106
79
NS
115
96 ± 16
Ky (unoccupied)
Entry*
Liv
Kit*
Din*
Bed
pre-dicamba
nd
nd
NS
NS
NS
pre-2,4-D
nd
0.24
NS
NS
NS
3,4-D rec, %
78
74
NS
NS
NS
post-dicamba
0.11
0.04
nd
NS
nd
post-2,4-D
1.02
0.54
nd
NS
0.05
3,4-D rec, %
86
95
78
NS
90
84 ± 8
B-9
-------
Table 7. Surface Loading by Traffic Pattern: 2,4-D on Bare Floors by Wipe, Yr2
Home/ Time Surface Loading of Analyte in Dust, ng/m2
recovery
BY
Entry
Liv
Din
Kit* Bed
3,4-D
pre-2,4-D
nd
3,4-D, %
73'
post-2,4-D
7.85
3,4-D, %
76
75 ±2
Rr
Entry*
Din*
Kit*
Liv Bed
pre-2,4-D
0.68
NS
0.68
3,4-D, %
88
NS
77
post-2,4-D
2.64
NS
1.41
. 3,4-D, %
67
NS
65
74 ± 11
Lb
Ent/Kit*
Din
Liv
Bed Fam
pre-2,4-D
nd
3,4-D, %
78
post-2,4-D
2.22
3,4-D, %
65
72 ±6
Nc (unoccupied)
Entry*
Liv
Kit*
Din Bed
pre-2,4-D
nd
nd
3,4-D, %
84
92
post-2,4-D
0.98
0.76
3,4-D, %
81
79
84 ±6
Ky (unoccupied)
Entry*
Liv
Kit*
Din* Bed
pre-2,4-D
nd
NS
NS
3,4-D, %
78
NS
NS
post-2,4-D
1.02
nd
NS
3.,4-D, %
86
78
NS
81 ±5
B-10
-------
Table 8. Comparison of Surface Loading of 2,4-D from Collection by PUF Roller and HVS3 on
Living Room Carpet, Yr2
Surface Loading of 2,4-D by PUF Roller and HVS3 Collection, ug/m2
Pre-Application Sampling Post-Application Sampling
Home PUF Roller 3.4-D.%* HVS3 PUF Roller 3,4-D,%* HVS3
BY 0-22 55 4.92 0.77 69 42.5
Zm ND" 67 0.17 0.02 98 5.63
Rr ND 70 0.54 0.19 72 20.1
Lb ND 46 0.65 0.05 72 4.62
Nc NSb NS 0.25 0.23 71 1.90
Ky NS NS 0.24 0.18 63 0.54
HVS3 vs PR ave 3,4-D HVS3 vs PR ave 3,4-D
i^= NT 60 ± 11 r*= 0.96 74 ±12
* recovery of 3,4-D from analysis of PUF Roller sleeve
a) ND= not detected
b) NS= not sampled
B-l 1
-------
Table 9. Comparison of Air Exchange Rates and 2,4-D Deposition Coupon Levels, Yr 2
Infiltration
Rate
Air Exchange
Rate
2,4-D Deposition, mg/m2*
Coupon Placement with respect to
Home
Home
m3/hr
L/hr
Coupon 1
Coupon 2
Coupon 3
average
BY
117
0.25
48.7
S
41.8
NW
46.8
NE
45.8
Zm
831
1.43
40.0
W
66.9
E
59.9
S
55.6
Rr
78
0.19
55.4
SW
57.2
SE
21.5
NE
44.7
Lb
177 .
0.43
45.3
S
46.8
N
38.4
W
43.5
NC
203
0.17
38.4
W
41.9
E
64.3
SE
48.2
KY
70
0.10
50.8
SW
43.5
SE
50.8
NE
48.3
* Desired application rate= 84 mg/m2
B-12
-------
I
Table 10. QA/QC Samples for Air Samples, Yr2
Medium
QA/QC
Type
Amount of Analyte:
Level or Recovery of 2,4-D
Recovery of 3,4-D, %
Average:
ng or %
%
Equivalent
Air Cone,
ng/m3
URG-filter
field blank
(pre)
2,4-D, ng: 3.6, 5.4, 0.3,0.0,
3,4-D, %: 92, 96, 80, 78
listed
below
field blank
(post)
2,4-D, ng: 2.7, 0.0, 0.3, 0.0
3,4-D, %: 93, 81, 82, 82
1.5 ± 2.1
86 ±7
0.3
(50 ng)*
lab blank
2,4-D, ng: 0.0, 11.3
3,4-D, %: 76,83
5.7 ±5.7
80 ±3
1.0
(50 ng)*
lab spike w
storage
2,4-D, %: 102, 89
3,4-D, %: 87,85
96 ± 7
86 ± 1
8.7
(50 ng)*
lab spike
2,4-D, %: 111, 79
3,4-D, %: 92,92
95 ± 16
92 ±0
8.7
(50 ng)*
solvent
spike
2,4-D, %: 76
3,4-D, %: 85
76
85
8.7
(50 ng)*
URG-PUF
field blank
(pre)
2,4-D, ng:6.1, 4.2, 13.6, 8.3
3,4-D, %: 77, 64, 95, 62
listed
below
field blank
(post)
2,4-D,ng:10.5, 8.8, 13.7, 26.3
3,4-D, %: 89, 65, 88, 125
11.4±6.9
83 ±21
2.0
(50 ng)*
lab spike
2,4-D,%: 67, 71, 57, 90
3.4-D.%: 72,61,56, 75
71 ± 14
66 ±9
8.7
(50 ng)*
* ng quantity of 3,4-D spiked
B-13
-------
Table 10. QA/QC Samples for Air Samples, Yr2 (Continued)
Medium QA/QC Amount of Analyte: Average: Equivalent
Type Level or Recovery of 2,4-D ng or % Air Cone,
Recovery of 3,4-D, % % ng/m3
Cascade
Impactor-
plate
field blank
2,4-D, ng: 2.2,2.2,2.3
3,4-D, %: 94, 72, 101
2.2 ±0.1
89 ± 15
1.5
(50 ng)*
lab blank
2,4-D, ng: 15.6, 18.4, 16.2
3,4-D,%: NS, NS, NS
16.7±1.5
NS
11.1
NS
lab spike
2,4-D, %: 62
3,4-D,%: 57
62
57
33.3
(50 ng)*
Cascade
Inpactor-
filter
field blank
2,4-D, ng: 7.8
3,4-D, %: 112
7.8
112
5.2
(50 ng)*
lab spike
2,4-D, %: 59
3,4-D, %: 52
59
52
33.3
(50 ng)*
B-14
-------
Table 11. QA/QC Samples for Dust Samples (Floors/Sills/Tables), Yr2
QA/QC Type:
Home-Application
Period
Total 2,4-D
measured, ng
3,4-D Recovery, %
(250 ng spike)
Equivalent 2,4-D
loading, (ig/m2
Wipe Field Blank
(table loading)
By: pre-appl
159
89
1.86
By: post-appl
96
78
1.12
Zm: pre-appl
63
78
0.74
Zm: post-appl
26
79
0.30
Rr: pre-appl
47
80
0.55
Rr: post-appl
49
104
0.57
Lb: pre-appl
179
109
2.10
Lb: post-appl
50
104
0.59
Nc: pre-appl
48
92
0.56
Nc: post-appl
38
108
0.44
Ky: pre-appl
154
94
1.80
Ky: post-appl
166
74
1.94
lab blank
148
7 7
1.73
lab spike
79
7 2
1.17
PUF Roller
field blank
259,292
59%, 79%
0.54, 0.61
lab blank
229,311
73%, 90%
0.48, 0.65
Dust-solvent blank
0.0
NS
0.000 (floor loading)
0.0
122
0.000 (floor loading)
B-15
-------
Table 11. QA/QC Samples for Dust Samples (Floors/Sills/Tables), Yr2 (Continued)
QA/QC Type:
Home-Application
Period
2,4-D Recovery,%
(100 ng spike)
3,4-D Recovery, %
(250 ng spike)
Equivalent 2,4-D
loading, ng/m2
Wipe Field Spike
(table loading)
By: pre-appl
102
93
By: post-appl'
160
73
Zm: pre-appl
99
74
Zm: post-appl
140
84
Rr: pre-appl
117
86
Rr: post-appl
172
104
Lb: pre-appl
110
109
Lb: post-appl
173
84
Nc: pre-appl
115
96
Nc: post-appl
130
83
Ky: pre-appl
NT
NT
Ky: post-appl
137
79
lab spike
79
72
PUF Roller
lab spike
83%, 59%
86%, 83%
1.04
B-16
-------
Table 12. Surface Areas Wiped or Vacuumed and Dust Quantity Collected, Yr2
Home
Floor Area Sampled,
2
m
HVS3 Floor
Dust- g
Sill Area,
2
m
Table
Area, m2
Traffic HVS3
Density/Room
Wipe PUF pre- post-
Roller appl appl
By: Entry
Liv
Din
Kit*
Bed
1.0
2.24
NS"
NS
2.0
0.2
0.48
1.39
1.68
NS
1.40
1.59
5.12
NS
5.02
0.142
NS
0.054
0.094
0.0854
NS
0.0854
0.0854
Entry
2.0
1.75
2.40
Kit
2.0
0.16
0.95
0.0948
oo
o
o
Liv
2.0
0.48 0.34
0.71
0.2748
0.0854
Din
NS
NS
NS
NS
NS
Bed
2.0
0.62
1.13
0.0929
0.0854
Rr: Entry*
Din*
Kit*
Liv
Bed
NS
NS
NS
2.0
21.75
'0.2
NS
0.2
0.48
NS
1.99
0.42
NS
4.96
0.96
NS
0.1008
0.2015
0.1234
NS
0.0854
0.0854
0.0854
Lb: Entry* NS 0-2
Din
1.6
0.51
0.99
0.0429
0.0854
Liv
2.0
0.48 0.58
1.28
0.1974
0.0854
Kit
NS
NS
NS
NS
NS
Bed
2.0
0.59
0.95
0.0426
0.0854
B-17
-------
Table 12. Surface Areas Wiped or Vacuumed and Dust Quantity Collected, Yr2 (Continued)
Home
Floor Area Sampled,
m
HVS3 Floor
Dust, g
Sill Area,
„2
m
Table
Area, m2
Traffic HVS3 wipe PUF
Density/Room Roller
pre-
appl
post-
appl
NC: Entry*
Liv
Kit*
Din*
Bed
NS
2.0
NS
NS
2.0
0.2
0 2
NS
0.48 0.94 1.12
NS NS NS
NS 1.03
0.0854
0.0854
NS
0.0854
Ky: Entry*
Liv
Kit*
Din*
Bed
NS
2.0
NS
NS
2.0
0.2
0.2
NS
0.48
0.22
NS
NS
NS
0.23
NS
0.12
0.0519
0.0519
NS
0.0519
0.0854
0.0854
NS
0.0854
* bare floor
a) NS= not sampled
B-18
-------
Table 13. Comparison of Floor Dust Loading, 2,4-D Loading and 2,4-D Dust Concentration,
Yr2
Home Location
BY
Entry
Liv
Din
Kit
Bed
Pre
dust, g/m2
0.70
0.83
NS
wipe
0.89
2,4-D ^g/m2
3.16
4.92
NS
wipe
4.29
2,4-D/ig/g
4.54
5.92
NS
wipe
4.84
Post
dust, g/m2
1.59
2.29
NS
wipe
2.51
2,4-D £ig/m2
75.9
42.5
NS
wipe
31.9
2,4-D/^g/g
47.7
18.6
NS
wipe
12.7
Zm
Entry
Kit
Liv
Din
Bed
Pre
dust, g/m2
0.88
0.11
0.16
NS
0.34
2,4-D /ig/m2
0.43
0.19
0.17
NS
0.22
2,4-D//g/g
0.49
1.65
1.03
NS
0.63
Post
dust, g/m2
1.20
0.48
0.36
NS
0.57
2,4-D /ig/m2
23.8
8.72
5.63
NS
5.21
2,4-D/^g/g
19.9
18.4
15.9
NS
9.22
Rr
Entry
Din
Kit
Liv
Bed
Pre
dust, g/m2
wipe
NS
wipe
1.11
0.28
2,4-D Aig/m2
wipe
NS
wipe
0.54
2.65
2,4-D^g/g
wipe
NS
wipe
0.49
9.45
Post
dust, g/m2
wipe
NS
wipe
2.48
0.55
2,4-D /^g/m2
wipe
NS
wipe
20.1
5.01
2,4-D/^g/g
wipe
NS
wipe
8.11
9.13
B-19
-------
Table 13. Comparison of Floor Dust Loading, 2,4-D Loading and 2,4-D Dust Concentration,
Yr 2 (Continued)
Home Location
Lb
Ent/Kit
Din
Liv
Bed
Fam
Pre
dust, g/m2
wipe
0.35
0.33
0.41
NS
2,4-D Mg/m2
wipe
1.02
0.65
1.04
NS
2,4-D^g/g
wipe
2.89
1.96
2.54
NS
Post
dust, g/m2
wipe
0.62
0.64
0.48
NS
2,4-D /ig/m2
wipe
6.50
4.62
4.40
NS
2,4-D|Ug/g
wipe
10.5
7.22
9.26
NS
NC
Entry
Liv
Kit
Din
Bed
Pre
dust, g/m2
wipe
.47
wipe
NS
NS
2,4-D /ug/m2
wipe
0.25
wipe
NS
NS
2,4-D/ig/g
wipe
0.53
wipe
NS
NS
Post
dust, g/m2
wipe
0.56
wipe
NS
0.52
2,4-D ,ug/m2
wipe
1.90
wipe
NS
0.81
2,4-DMg/g
wipe
3.40
wipe
NS
1.57
KY
Entry
Liv
Kit
Din
Bed
Pre
dust, g/m2
wipe
0.11
NS
NS
NS
2,4-D Mg/m2
wipe
0.24
NS
NS
NS
2,4-D^g/g
wipe
2.18
NS
NS
NS
Post
dust, g/m2
wipe
0.12
wipe
NS
0.06
2,4-D /ig/m2
wipe
0.54
wipe
NS
0.05
2,4-D//g/g
wipe
4.66
wipe
NS
0.90
B-20
-------
Table 14. Designation of Homes by Activity Patterns, Yr 2
Activity Pattern
Child Activity
Shoes Worn
Indoors
Pet Activity
Applicator
Shoes Worn Indoors
BY
HiC
S
Lo P(~)a
NAS
Zm
Mod C
S
LoP
NAS
Rr
HiC
NS(~)b
LOP
NAS
Lb
Lo c
NS(~)b
LOP
'NAS
Nc (unoccupied)
Lo c
NS
LOP
NAS
Ky (unoccupied)
LoC
NS
LoP
NAS
a) dog was kept under greater control after application
b) removal of shoes at the door was not enforced as stringently as in the first year study
B-21
-------
Table 15. Air Volumes Sampled, Yr2
Total Air Volume Sampled in Particle Size Range, m3
Home: sample
<1 um
<2.5 um
<10 um
TSP
By: pre-URG
5.64
5.57
5.60
5.67
postl-URG
5.59
5.63
5.50
5.56
post3-URG
5.80
5.85
stopped
5.73
cascade impactor
0.73
0.73
0.73
0.73
Zm: pre-URG
5.86
3.96
5.77
5.52
post 1 -URG
5.61
5.70
5.55
5.68
post3-URG
6.01
5.98
6.10
6.09
cascade impactor
0.78
0.78
0.78
0.78
Rr: pre-URG
5.56
5.98
5.66
5.26
postl-URG
5.79
5.92
5.96
6.04
post3-URG
5.84
stopped
6.01
5.98
cascade impactor
0.81
0.81
0.81
0.81
Lb: pre-URG
5.71
5.36
5.53
5.58
post 1 -URG
5.70
5.30
5.57
5.87
post3-URG
5.83
5.70
5.86
5.83
cascade impactor
1.0
1.0
1.0
1.0
B-22
-------
Table 15. Air Volumes Sampled, Yr2 (Continued)
Total Air Volume Sampled by Particle Size Range, m3
Home: sample
<1 um
<2.5 um
<10 um
TSP
Nc: pre-URG
NS
NS
NS
NS
postl-URG
6.08
stopped
5.97
5.51
post3-URG
5.54
5.68
5.75
5.90
cascade impactor
0.94
0.94
0.94
0.94
Ky: pre-URG
NS
NS
NS
NS
post 1 -URG
5.84
5.92
5.68
5.81
post3-URG
6.13
6.17
6.36
5.47
cascade imuactor
0.75
0.75
0.75
0.75
B-23
-------
APPENDIX C
-------
Table 1. 2,4-D in Air by Particle Size, Application 2h Samples, Yr3
Table 2. 2,4-D in Air by Particle Size, Post-Application 24h Samples, Yr3
Table 3. Surface Loading of 2,4-D on Living Room Table and Floor, Yr3
Table 4. Personal Exposure Data: Handwipes, Yr3
Table 5. Personal Exposure Data: Urine, Yr3
Table 6. Lawn Deposition Rates of 2,4-D, Yr3
-------
Table 1. 2,4-D in Air by Particle Size, Application 2h Samples, Yr3
Indoor Concentration of 2,4-D during Application, ng/m3
Home
<1 urn
1-2 |im
2-8 |im
8-20 Jim
BY
nd, <3a
nd
nd
nd
Zm
3.3
3.3
15.3
8.7
c s
nd
nd
nd
nd
Rr
nd
nd
nd
nd
a) nd= not detected, less than detection limit given
C-l
-------
Table 2. 2,4-D in Air by Particle Size, Post-Application 24h Samples, Yr3
Indoor Concentration of 2,4-D Post Application, ng/m3
Home
Day
TSP
<10 nm
<2.5
<1 (im
BY
Day 1
4.78
2.43
0.67
2.42
Day 3
3.80
5.06
1.03
0.88
Zm
Day 1
6.40
3.54
1.42
2.13
Day.3
0.89
0.65
0.24
0.18
Cs
Day 1
0.39
SLa
0.15
0.37
Day 3
1.22
0.88
0.56
1.10
Rr
Day 1
0.22
0.07
SL
ND
Day 3
ND, <0.1b
ND
ND
ND
a) SL= sample lost from pump failure
b) ND= not detected, less than detection limit given
c-2
-------
Table 3. Surface Loading of 2,4-D on Living Room Table and Floor, Yr3
Surface Loading of 2,4-D, p.g/m2
Home Surface Pre-Appl. Post-Appl. Post-Appl. Post-Appl.
Day 1 Day 3 Day 7
BY
Table-incremental""
0.05
0.18
0.94
1.97
Floor-incremental (m)^
0.60
6.14
7.38
3.65
Table-cumulative (m)(c)
0.18
1.12
3.09
Floor-cumulative(d)
-
6.14
13.52
17.17
Zm
Table-incremental
0.03
0.21
0.54
0.84
Floor-incremental
0.04
0.63
2.43
1.06
Table-cumulative
0.21
0.75
1.59
Floor-cumulative
-
0.63
3.06
4.12
Rr
Table-incremental
0.01
co.01
0.07
0.05
Floor-incremental
0.10
1.55
0.75
0.20
Table-cumulative
co.01
0.07
0.12
Floor-cumulative
1.55
2.30
2.50
c s
Table-incremental
0.01
co.01
0.05
0.07
Floor-incremental
0.03
0.33
0.88
1.23
Table-cumulative
co.01
0.05
0.12
Floor-cumulative
-
0.33
1.21
2.44
(a) Incremental addition of 2,4-D that is added in each interval: Application to end of Day 1;
Day 1 to Day 3; Day 3 to Day 7.
(b) Same as (a); measurement (m) is made on floors as incremental additions.
(c) Summed additions; measurement (m) on tables taken as cumulative loadings.
(d) Summed loadings incremental additions.
c-3
-------
Table 4. Personal Exposure Data: Handwipes, Yr3
Total 2,4-D on Hands, ng
Home
Subject
Pre-Appl.
Post-Appl.
Day 1
Post-Appl.
Day 3
Post-Appl.
Day 7
BY
adult
26
56,900"
378
51
child
100
10b
95
1060
Zm
adult
1740"
28,300
864
179
child
17
92
8
53
Cs
adult
ndd
29"
40
25
child
nd
ndf
68
nd
Rr
adult
24
927
600
52
child
46
41
nd
22
a) Application made just before dinner; applicator finished job and then wiped hands for
sample
b) Child not at home during application (at swim practice); came in and wiped hands for
sample
c) Residual level from application made 3 weeks earlier (washed out by heavy rains within 12
hours of application, so reapplied)
d) By the looks of the lawn, no 2,4-D had been applied for 1-2 years
e) Applicator wore gloves during application
f) Child not at home during application
c-4
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Table 5. Personal Exposure Data: Urine, Yr3
Total 2,4-D Excreted in First Morning Void, ng
Home
Subject
Pre-Appl.
Post-Appl.
Day 2
Post-Appl.
Day 3
Post-Appl.
Day 4
Post-Appl.
Day 8
BY
adult
1097
1116
1568
1220
655
child
107"
78
597
503
198
Zm
adult
116"
419
220
405
65
child
625(?)a'b
190
175
714
288
Cs
adult
1875(7)^
199
159
615
237
child
109"
405
876
316
nd
Rr
adult
child
2122(?fb
97"
1208
836
300
560
a) Analysis using GC/ECD rather than GC/MS
b) ? - suspect value; not repeated with GC/MS analysis
c-5
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Table 6. Lawn Deposition Rates of 2,4-D, Yr3
Deposition, mg/m2
Coupon 1
Coupon 2
Coupon 3
Average
BY
29.6
32.6
22.7
28.3
Zm
22.7
19.3
24.8
22.3
c s
53.8
0
0
17.9
Rr
2.27
1.05
0.75
1.4
C-6
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