-------
1
2 Table 5-15. Daily Soil Ingestion Estimation in a Soil-pica
3 . Child by Tracer and by Week (mg/day)
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
Tracer
Al
Ba
Mn
Si
Ti
V
Y
Zr
Week I
Estimated Soil Ingestion
74
458
2,221
142
1,543
1,269
147
86
Week 2
Estimated Soil Ingestion
13,600
12,088
12,341
10,955
11,870
10,071
13,325
2.695
Source: Calabrese et al. (1991).
June 2000 5-40 DRAFT-DO NOT QUOTE OR CITE
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1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
Table 5-16.
Ratios of Soil,
Dust, and Residual Fecal
Samples in the Soil Pica Child
Tracer Ratio
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
Pairs
Mn/Ti
Ba/Ti
Si/Ti
V/Ti
Ai/Ti
Y/Ti
Mn/Y
Ba/Y
Si/Y
V/Y
Al/Y
Mn/AI
Ba/Al
Si/Al
V/A1
Si/V
'Mn/Si
Ba/Si
Mn/Ba
Source: Calabreseand
Soil
208.368
187.448
148.117
14.603
18.410
8.577
24.293
21.854
17.268
1.702
2.146
11.318
10.182
8.045
0.793
10.143
1.407
1.266
1.112
Stanek(1992).
Fecal
215.241
206.191
136.662
10.261
21.087
9.621
22.373
21.432
14.205
1.067
2.I'92
10.207
9.778
6.481
0.487
13-318
1.575
1.509
1.044
Dust
260.126
115.837
7.490
17.887
13.326
5.669
45.882
20.432
1.321
3.155 .
2.351
19.520
8.692
0.562
1.342
0.419
34.732
15.466
2.246
Estimated % of Residual Fecal Tracers
of Soil Origin as Predicted by Specific
Tracer Ratios
87
100
92
100
100
100
100
71
81
100
88
100
73
81
100
100
99
83
100
June 2000
5-41
DRAFT-DO NOT QUOTE OR CITE
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1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
Table 5-17. Daily variation of Soil Ingestion by Children Displaying Soil Pica in Wong (1988)
Child subject number Month Estimated soil ingestion
(mg/dayr
Glenhope Place of Study
Number 1 1
Number 12
Number 14
Number 18
Number 22
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4
55
1,447
22
40
0
0
7,924
192
1,016
464 .
2,690
898
30
10,343
4,222
1,404
0
5,341
0
Reddles Place of Study
Number 27
1
2
3
4
48,314
60,692
51,422
3,782
Source: Calabrese and Stanek (1993).
June 2000
5-42
DRAFT-DO NOT QUOTE OR CITE
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1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
Table 5-18. Prevalence of Non-Food Ingestion/Mouthing Behaviors fay Child's Age:
Percent of Children Whose Parents Reports the Behavior in the Past Month
Child's Age (years)
Non-Food Ingestion/mouthing prevalence
Outdoor "soil" mouthing/Ingestion
Sand, stones
Grass, leaves, flowers
Twigs, sticks, woodchips
Soil, dirt
Dust, lint, dustballs
Plaster, chaik
Paintchips, splinters
General mouthing of objects
Other toys
Paper, cardboard, tissues
Teething toys
N
% > Monthly
% > Weekly
% Daily
% > Monthly
% > Weekly
% Daily
% > Monthly
% > Weekly
% Daily
% > Monthly
% > Weekly
% Daily
% > Monthly
%> Weekly
% Daily
% > Monthly
%> Weekly
%,Daily
% > Monthly
%> Weekly
% Daily
% > Monthly
% > Weekly
% Daily
% > Monthly
% > Weekly
% Daily
% > Monthly
%> Weekly
% Daily
1
171
54
36 .
17
48
34
16
42
29
12
38
24
11
14
1
2
8
5
2
6
2
0
88
82
63
71
54
28
65
55
44
2
70
26
10
0
16
7
0
23
7
0
21
7
0
4
1
0
10
3
0
0
0
0
53
44
27
37
23
9
29
16
6
3
93
19
6
2
24
14
2
13
9
0
5
3
i
2
1
0
3
0
0
0
0
0
64
42
20
32
20
8
15
9
6
4
82
9
2
1
13
4
1
13
5
1
7
2
0
0
0
0
2
I
1
4
1
0
44
26
9
23
12
5
4
1
0
5
90
7
4
1
9
6
1
11
7
0
3
1
1
0
0
0
3
0
0
1
0
0
42
28
7
18
7.
2
3
1
0
6
22
9
5
5
5
0
0
5
0
0
9
9
0
5
0
0
5
0
0
0
0
0
23
9
5
14
9
5
9
9
9
All
528
27
16
6
26
16
6
23
14
4
18
10
4.
6
3
1
5
2
1
3
1
0
62
49
30
41
28
13
29
22
17
June 2000
DRAFT-DO NOT QUOTE OR CITE
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Table 5-18.' Prevalence of Non-Food Ingestion/Mouthing Behaviors by Child's Age:
Percent of Children Whose Parents Reports the Behavior in the Past Month (continued)
1 Crayons, pencils, erasers
2
3
4 Blankets, cloth
5
6
7 Shoes, Foorware
8
9
10 Clothing
11
12
13 Other items
14
15
16 Crib, chairs, furniture
17
18
19 Sucking of fingers, etc
20 Suck fingers/thumb
21
22
23 Suck feet or toes
24
25
26 Use pacifier
27
28
29 Suck hair
30
31
% > Monthly
% > Weekly
% Daiiy
% > Monthly
% > Weekly
% Daily
% > Monthly
% > Weekly
% Daily
% > Monthly
% > Weekly
% Dajly
% > Monthly
% > Weekly
% Daily
% > Monthly
% > Weekly
% Daily
% > Monthly
% > Weekly.
% Daily
% > Monthly
% > Weekly
% Daily
% > Monthly
% > Weekly
% Daily
% > Monthly
% > Weekly
% Daily
56
41
19
51
42
29
50
42
20
49
39
25
41
35
22
37
26
13
67
60
44
37
23
8
24
22
20
1
1
1
54
37
17
21
17
11
23
10
1
34
24
7
30
26
ii
11
9
3
41
27
21
14
4
1
9
9
6
3
3
I
46
25
4
26
17
9
8
3
0
37
23
11
30'
24
15
8
3
1
43
31
22
12
3
0
6
5
5
8
2
1
50
27
6
22
18
' 13
7
2
0
43
28
9
23
15
7
10
5
1
57
43
26
11
2
I
2
2
1
9
2
0
41
26
4
22
14
7
2
1
0
26
16
6
21
10
6
4
2
0
39
31
24
3
I
0
2
2
1
10
4
2
36
27
18
14
14
5
5
5
0
27
14
14
27
14
5
5
0
0
41
18
14
0
0
0
5
0
0
5
5
0
50
32
12
32
25
16
22
16
7
.39
27
14
31
23
14
17
11
5
52
41
30
18
9
3
11
10
9
5
2
1
June 2000
5-44
DRAFT-DO NOT QUOTE OR CITE
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Table 5-18. Prevalence of Non-Food Ingestion/Mouthing Behaviors by Child's Age:
Percent of Children Whose Parents Reports the Behavior in the Past Month (continued)
1 "Disgusting" object mouth ing/ingestion
2 Soap, detergent, shampoo
3
4
5 . Plastic, plastic wrap
6
7
8 Cigarette butts, tobacco
9
10
1 1 Matches
12
13
14 Insect
15
16
17 Other ingestion and behaviors
18 Toothpaste
19
20
21 Chew gum
22
23
24 . Bite nails
25
26
27 Suck hair
28
29
30
31 "Source: Staneketal. (1998).
32
33
% > Monthly
% > Weekly
% Daily
% > Monthly
% > Weekly
% Daily
% > Monthly
% > Weekly
% Daily
, % > Monthly
% > Weekly
% Daily
% > Monthly
% > Weekly
% Daily
% > Monthly
%> Weekly
% Daily
% > Monthly
% > Weekly
% Daily
% > Monthly
% > Weekly
% Daily
% > Monthly
% > Weekly
% Daily
-
48
37
15
32
22
7
16
10
4
6
2
1
5
2
0
63
60
52
18
10
3
8
5
2
62
57
42
34
27
14
19
11
4
6
4
0
4
3
0
1
0
0
97
94
87
56
40
17
26
23
7
76
64
39
24
14
3
8
3
1
5
4
1
1
1
0
2
}
1
92
91
86
76
60
18
31
24
12
85
77
43
!7
11
2
7
4
0
4
1
1
4
1
0
4
4
2
94
93
93
76
60
13
29
20
9
96
88
55
9
6
0
9
4
1
3
2
1
I
1
0
2
2
2
93
92
89
91
69
21
33
26
10
88
81
52
9
9
0
0
0
0
5
5
0
0
0
0
0
0
0
86
86
82
100
68
36
59
45
14
73
68
45
29
21
8
17
10
3
8
5
2
4
2
0
3
2
1
84
82
77
58
43
14
24
18
7
78
71
45
June 2000
5-45
DRAFT-DO NOT QUOTE OR CITE
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1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Table 5-19. Average Outdoor Object Mouthing Scores for Children by
Age, Frequency of Sand/Dirt Play, and General Mouthing Quartiies
1 Year old
Sand/dirt play?
Outdoor object >Daily Daily
mouthing scores Mean N Mean N
General mouthing
Score quart iles (Mean)
1st Quartile(1.5) 0.1 19 2.8 16
2nd Quartile (9.7) 0.7 14 3.9 1 1
3rd Quartile ( 19.6) 1.3 33 10.5 22
4th Quartile (3 5.6) 3.6 35 14 23
Slope based on general
mouthing quartile score 0-M ฐ34
SE 0.052 0.060
Source: Stanek et al. ( 1 998).
Age 2 to 6 years
Sand/dirt play?
>DaiIy Daily
Mean N Mean N
0.1 139 0.5 117
0.3 27 0.8 28
0.2 19 1.8 21
0.5 2 1.5 4
0.007 0.054
0.021 0.019
June 2000
5-46
DRAFT-DO NOT QUOTE OR CITE
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1 Table 5-20. Summary of Estimates of Soil Ingestion by Children
2
3 Mean (mg/day)
4 Al Si AIR1 Ti , Y
5 181 184
6 230 129
7 39 82 245.5
8 64.5" 160" 268.4"
9 153 154 218 85
10 154" 483b 170" 65"
11 122 139 - 271 165
12 133e
13 69-120"
14 66'
15 196b
16 Average = 138 mg/day soil
17 1 93 mg/day soil and dust combined
18 'AIR = Acid Insoluble Residue
1 9 "Soil and dust combined
20 CBTM
21 "LTM; corrected value
22
23
24
25
26
Upper Percentile (mg/day) References
Al Si Ti Y
584 578 Binder etal. 1986
Clausing etal. 1987
Davis etal. 1990
223 276 1,432 106 Calabrese etal. 1989
478" 653" 1,059" 159"
254 224 279 144 Stanek and Calabrese, 1995a
2 1 T Stanek and Calabrese, 1 995b
Van Wynen et al. 1990
280' Calabrese etal. 1997
994"
358 mg/day soil
790 mg/day soil and dust combined
,
27 Table 5-2 1 . Summary of Recommended Values for Soil Ingestion
28 Population Mean
29 Children (age 1 -6 years) 1 00
30 Pica child 10
Upper Percentile
mg/day 400 mg/day
g/day -~
3 1 "200 mg/day may be used as a conservative estimate of the mean (see text).
32 bStudy period was short; therefore, these values are not estimates of usual intake.
33 To be used in acute exposure assessments. Based
34
35
36
on only one pica child (Calabrese et al., 1989).
June 2000
5-47
DRAFT-DO NOT QUOTE OR CITE
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1
2
3
4
5
6
8
9
10
11
12
Table 5-22. Confidence in Soil Intake Recommendation
Considerations
Rationale
Rating
13
14
15
16
17
18
19
20
21
22
Study Elements
Level of peer review
Accessibility
Reproducibility
Focus on factor of interest
Data pertinent to U.S.
Primary data
Currency
Adequacy of data collection period
Validity of approach
Study size
Representativeness of the population
Characterization of variability
Lack of bias in study design (high
rating is desirable)
Measurement error
Other Elements
Number of studies
Agreement between researchers
Overall Rating
All key studies are from peer review literature.
Papers are widely available from peer review journals.
Methodology used was presented, but results are difficult
to reproduce.
The focus of the studies was on estimating soil intake rate
by children: studies did not focus on intake rate by adults.
Two of the key studies focused on Dutch children: other
studies used children from specific areas of the U.S.
All the studies were based on primary data.
Studies were conducted after 1980.
Children were not studied long enough to fully
characterize day to day variability.
The basic approach is the only practical way to study soil
intake, but refinements are needed in tracer selection and
matching input with outputs. The more recent studies
corrected the data for sources of the tracers in food. There
are. however, some concerns about absorption of the
tracers into the body and tag time between input and
output
The sample sizes used in the key studies were adequate for
children. However, only few adults have been studied.
The study population may not be representative of the U.S.
in terms of race, socio-economics, and geographical
location: Studies focused on specific areas: two of the
studies used Dutch children.
Day-to-day variability was not very well characterized.
The selection of the population studied may introduce
some bias in the results (i.e., children near a smelter site,
volunteers in nursery school. Dutch children).
Errors may result due to problems with absorption of the
tracers in the body and mismatching inputs and outputs.
There are 7 key studies.
Despite the variability, there is general agreement among
researchers on central estimates of daily intake for
children.
Studies were well designed: results were fairly consistent:
sample size was adequate for children and very small for
adults; accuracy of methodology is uncertain: variability
cannot be characterized due to limitations in data
collection period. Insufficient data to recommend upper
pgrcentile estimates for both children and adults.
High
High
Medium
High (for children)
Low (for adults)
Medium
High
High
Medium
Medium
Medium (for
children)
Low (for adults)
Low
Low
Medium
Medium
High
Medium
Medium (for
children - long-term
central estimate)
Low (for adults)
Low (for upper
percentile)
23
June 2000
5-48
DRAFT-DO NOT QUOTE OR CITE
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1 6. OTHER NON-DIETARY INGESTION FACTORS
2
3 6.1 INTRODUCTION
4 Young children (i.e., ages 6 months through approximately 4 years) also have the
5 potential for exposure to toxic substances through non-dietary ingestion pathways other than soil
6 ingestion (e.g., ingesting pesticide residues that have been transferred from treated surfaces to the
7 hands or objects that are mouthed). These children have an urge to mouth objects or their fingers
8 in exploring their environment, as a sucking reflex, and as a habit (Groot et al., 1998). This route
9 of exposure may exceed other routes ingestion (i.e., food, pica, drinking water, breast milk) and
10 dermal exposure because non-dietary ingestion may result in higher ingestion rates of
11 contaminated material (Weaver et al., 1998). This exposure route is also a difficult route to
12 model because there is little literature or research that has been performed on mouthing behavior
13 (Reed et al., 1998) and little information on the susceptibility of children to toxic substances
14 (Weaver etal., 1998).
15 Mouthing behavior includes all activities in which objects, including fingers, are touched
16 by the mouth or put into the mouth except for eating and drinking, and includes licking, sucking,
17 chewing, and biting (Groot et al., 1998). This exposure route becomes difficult to model because
18 contact with surfaces is intermittent and nonuniform over different parts of the body. The
19 intermittent and nonuniform nature of the mouthing itself also makes this pathway difficult to
20 model (ZartarianetaL, 1997).
21 Children exhibit large differences in mouthing behavior (Groot et al., 1998). Infants are
22 bora with a sucking reflex for breast feeding, and within a few months, children begin to use
23 sucking or mouthing as a means to explore their surroundings. Children will use both sucking
24 and licking to explore their environment. Sucking also becomes a means of-comforting a child
25 when they are tired or upset. In addition, teething normally causes substantial mouthing
26 behavior, sucking or chewing, to alleviate discomfort in their gums. Each child is different, and
27 large differences occur between children, even within the same family.
28 Where mouthing becomes critical in exposure to potentially toxic substances is the
29 proximity and behavior of a small child around potentially contaminated sources. Children play
30 close to the ground and are constantly licking their fingers or mouthing toys or objects. As a
f 1 result, this becomes a potentially significant exposure route for children. They can ingest more
June 2000 6-1 DRAFT-DO NOT QUOTE OR CITE
-------
1 toxic constituents through this behavior than from dietary ingestion or inhalation because the
2 children could place wet, sticky fingers on potentially-contaminated surfaces where more toxic
3 constituents may adhere to the ringers than if the fingers were dry (Gurunathan et al., 1998).
4 Gurunathan et al. (1998) estimate that young children spend as much as 90 percent of
5 their days inside, so exposure to contaminants that may infiltrate the home (i.e., volatile and
6 semi-volatile organic constituents [VOCs and S VOCs]) through the vapor phase may be of
7 concern. This may be a significant pathway of exposure to S VOCs because these compounds
8 can be deposited on surfaces in the home or become absorbed onto plastic toys or in stuffed
9 animals where they can serve as reservoirs for toxic constituents (Gurunathan et al., 1998).
10 There have .been few studies investigating this potential exposure route. The shortage of
11 research and data may be due to the difficulty in observing very young children and the labor-
12 intensive effort in gathering the data (U.S. EPA, 1999). The applicable research efforts use two
13 general approaches to gather data: real-time hand recording in which trained persons observe a
14 child and manually record information on a survey sheet or score sheet; or, videotaping in which
15 trained videographers tape a child's activities and subsequently extract the pertinent data
16 manually or with computer software (U.S. EPA, 1999).
17 Some researchers express mouthing behavior in terms of frequency of occurrence (e.g.,
18 contacts/hour, contacts/minute). Others, express mouthing behavior as a rate in units of minutes
19 per hour of mouthing time. Both approaches have their use in.exposure assessments. The former
20 approach is more appropriate when studying children's behavior during various microactivities.
21 The latter, however, is more useful when studying children's behavior during macroactivities.
22 Macroactivities can be described by a child's general activities such as sleeping, watching
23 television, playing, and eating. Microactivities refer to the specific behavior a child is engaged in
24 such as hand-to-surface contacts and hand-to-mouth behavior (Hubal, 2000). Time spent in
25 various macroactivities in several microenvironments (e.g., indoors at home) are presented in
26 Chapter 9).
27
28 6.2 STUDIES RELATED TO NON-DIETARY INGESTION
29 Groot et al. (1998) - Mouthing Behavior of Young Children - In this study, Groot et al.
30 (1998) examined the mouthing behavior of infants and young children between the ages of 3 and
31 36 months, in the Netherlands. The study was actually part of a larger effort to determine if PVC
June 2000 6-2 DRAFT-DO NOT QUOTE OR CITE
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1 toys softened with phthalates could pose health risks to children from mouthing. As part of the
2 effort, Groot et al. (1998) asked parents to observe their children and gather information which
3 could be used to estimate how often children engage in mouthing and the duration spent
4 mouthing during a day. Parents were asked to observe their children ten times per day for 15-
5 minute intervals (i.e., 150 minutes total per day) for two days and measure mouthing with a
6 stopwatch.
7 In total, 36 parents participated in the study and 42 children were observed by their
8 parents. For the study, a distinction was made to differentiate between toys meant for mouthing
9 (e.g., pacifiers, teething rings) and those not meant for mouthing. The time a child spent
10 mouthing a dummy (e.g., pacifier) was not included in the time recorded. Although the sample
11 size was relatively small, the results provide a first-order estimate on mouthing times during a
12 day. Table 6-1 compiles the mouthing times from the Groot et al. (1998) effort. The results
13 show wide variation. The standard deviation in all four age categories except the 3- to 6-month
14 old children exceeds the mean time estimated mouthing during a day. The large standard
15 deviations is not unexpected given the vast behavioral differences from child to child and the
.16 small sample size of the study. The overall trend of the data, however, may be accurate in that it
17 shows that as the children age, the time spent mouthing decreases. The 3- to 6-month children
18 were estimated to mouth 37 minutes per day and the 6- to 12-month children 44 minutes per day.
19 After 12 months, the estimated mouthing time drops quickly to 16 minutes per day for 12- to 18-
20 month children and 9 minutes per day for 18- to 36-month children.
21 The study has several limitations that have an impact on the usability of the data. The
22 initial drawback concerns the small size of the study. Groot et al. (1998) acknowledge this
23 shortcoming and recommend further study using a larger sample population. In addition, the
24 study also incorporated mostly higher-educated persons. The area where the study was
25 performed consisted primarily of parents with higher education. The study had recruited persons
26 of lower education and socioeconomic levels, but these persons chose not to participate in the
27 study after recruitment (Groot et al., 1998). Therefore, the results do hot reflect data from the
28 full spectrum of the population. The study also recorded only the time spent mouthing and not
29 the number of times that mouthing occurred and did not differentiate the types of objects
30 mouthed. In addition, children were observed for a period of two consecutive days and may not
ll reflect long-term behavior. The study may not be representative of the U.S. population.
June 2000 6-3 DRAFT-DO NOT QUOTE OR CITE
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1 Reed et al. (1999) - Quantification of Children's Hand and Mouthing Activities through a
2 Videotaping Methodology - In -this study, Reed et al. (1999) used videotaping to quantify the
3 frequency and type of contacts children have during the course of an hour. The contacts included
4 numerous categories: hand to clothing, hand to dirt, hand to hand, hand to mouth, hand to object,
5 object to mouth, hand to smooth surface (e.g., counter tops, table tops), hand to textured surface
6 (e.g., stuffed animal) (Reed et al., 1999). A total of 30 children were observed in this study.
7 Children were observed in both day care (20 children 3-6 years old) and residential (10 children
8 2-5 years old) settings. Parents and day-care providers were also asked to complete
9 questionnaires describing the behavior of their children. In addition, the study also differentiated
10 between the usage of right and left hands.
11 Over the course of the research, Reed et al. (1999) found that the behavior of children
12 was similar between the day and residential settings except for the contact rate of hand to smooth
13 surfaces. Children in residential settings had higher contact rates with smooth surfaces than
14 children in day care centers. The results of the study are compiled in Table 6-2. The highest
15 contacts were with object (123 contacts/hr), smooth surfaces (84 contacts/hr), and other (83
16 contacts/hr). The two lowest contact rates were the hand-to-mouth (9.5 contacts/hr) and object-
17 to-mouth (16.3 contacts/hr) (Reed et al., 1999). Because the contact rates of hand-to-objects and
18 smooth surfaces are high, these results indicate that the fingers would appear to provide a
19 continual dose per hand-to-mouth contact because of constant touching of potentially
20 contaminated surfaces. Pesticides and other S VOCs are partitioned between the vapor and
21 deposited phases (e.g., on dust or absorbed on a plastic.toy or stuffed animal) such that a child's
22 fingers, especially if wet from mouthing, will continually be acquiring doses of these types of
23 constituents (Gurunathan et al., 1998). Reed et al. (1999) also noted that children acted equally
24 on their environment with both hands with the exception of object-to-mouth'behavior.
25 Therefore, the compiled data are reported as combined right and left hand data. The object-to-
26 mouth behavior showed a strong preference for the right hand over the left hand for nearly all
27 children (Reed et al., 1999). The preference ratio for the right hand over the left hand for this
28 category was 6.8 to 1 (Reed et al., 1999).
29 The advantages of the Reed et al. (1999) study is that it incorporates a wide variety of
30 contacts that small children have, not just the hand-to-mouth or object-to-mouth. This
31 information allows assessors to identify areas or surfaces that may serve as sources for toxic
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1 constituent transfer. This is especially important for exposure to SVOCs such as pesticides (e.g.,
2 chlorpyrifos) that have an affinity for absorption onto dust particles, plastic toys, and into the
3 polyurethane foam (PUF) that is used in many stuffed animals (Gurunathan et al., 1998).
\
4 Another strength of this study is the agreement it shows with earlier work by Zartarian et al.
5 (1998) for the hand to mouth contacts. Some of the shortcomings are the small sample size of
6 the study and the lack of comment as to the representativeness of the sample population to the
7 U.S. population. Reed et al. (1999) acknowledge the weakness in regard to the sample size and
8 recommend further work with a larger population. The study makes no mention of the
9 representativeness of the sample population or addresses the need for a representative population
10 for any additional study.
11 Zartarian et al. (1997) - Quantified Dermal Activity Data from a Four-Child Pilot Field
12 Study - Zartarian et al. (1997) conducted a pilot study of four children of farm workers to
13 investigate the applicability of using videotaping for gathering information related to children's
14 interaction with their environment. The evaluation of the videotaping included observation of
15 the children's contact frequency and duration with objects in their environment, duration spent in
.16 different locations, activity levels, and frequency distributions (Zartarian et al., 1997). As such,
17 the research was not specifically intended to gather data for non-dietary ingestion; however, the
18 activities used to evaluate the use of videotaping provide data were for dermal and non-dietary
19 exposure.
20 Four Mexican-American farm worker children between the ages of 2.5 and 4.2 years were
21 videotaped for 33 hours using hand-held cameras over the course of a single day in 1993
22 (Zartarian et al., 1997). Two girls and two boys were the subject of the videotaping. The
23 videotaping gathered information on detailed micro-activity patterns of children to be used to
24 evaluate software for videotaped activities and translation training methods (Zartarian et al.,
25 1997). The data were also reported by type of object/surface and by hand (i.e., left or right).
26 Zartarian et al. (1997) present the data for their observations on a per child and per hand
27 basis. The data suggest that the U.S. EPA (1997) estimate of hand to mouth contact of 1.56
28 contacts/hr may significantly underestimate the contacts per hour for young children. None of
29 the children had average contact frequencies for either hand, individually, lower than 3
30 contacts/hr for hand to mouth contact, and Zartarian et al. (1997) estimated the average as 9
rl contacts/hr. As was reported by Reed et al. (1999), the most frequently contacted objects were
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1 toys and hard (i.e., smooth) surfaces (Zartarian et al., 1997). Zartarian et al. (1997) report that
2 the average contact time with objects is only 2 to 3 seconds and that questionnaires and diaries,
3 therefore, would be insufficient in gathering that level of activity, r
4 The Zartarian et al. (1997) study has several weaknesses. The sample population is very
5 small, only four children; however, the work was reported as a pilot study completely
6 acknowledging that further work was necessary. The effort was intended to evaluate the
7 methodology of collecting observations, not the contact data itself. So the data are not presented
8 in a format that can be used to support other research or supply recommended estimates for
9 contact frequency. This study, may not reflect long-term behavior. In addition, the sample
10 population is not representative of the U.S. population in general because the sample population
11 consists of only four Mexican-American farm worker children.
12 Davis (1995), Soil Ingestion in Children with Pica (Final Report), EPA Cooperative
13 Agreement CR 816334-01 - In 1992, the Fred Hutchinson Cancer Research Center under
14 Cooperative Agreement with EPA conducted a study to estimate soil intake rates and collect
15 mouthing behavior data. Originally, the study was designed with two primary purposes: 1) to
16 describe and quantify the distribution of soil ingestion values in a group of children under the age
17 of five who exhibit behaviors that would be likely to result in the ingestion of larger than normal
18 amounts of soil; and 2) to assess and quantify the degree to which soil ingestion varies among
19 children according to season of the year (summer vs. winter). The study was conducted during
20 the first four months of 1992 and included 92 children from the Tri-Cities area in Washington
21 State. These children were volunteers among a group selected through random digit dialing and
22 their ages ranged between 0 and 48 months. The study was conducted during a period of 7 days.
23 Since there was no standard methodology to study mouthing behavior, a pretest and a
24 series of pilot studies were conducted to examine various aspects of the methodology. As a
25 result of the pilot studies, it was determined that although parents could be taught to conduct
26 observations using the instrument, the resulting ranking of children according to degree of
27 mouthing behavior did not correspond very well to the rankings based on observations of the
28 same children by trained staff observers. Therefore, using parents' observations to select a group
29 with high mouthing activity was not deemed appropriate. Funding constraints made it
30 impractical to continue with the original design of screening a large number of children and
31 conducting field work during two different times of the year.
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1 The Davis (1995) research recognizes that mouthing behavior is intermittent. Therefore,
2 a method called "interval method" of observation was used. This method measures both
3 frequency and duration of the behavior. Under this method, children were observed during 15
4 second intervals, during which the mouthing behavior was recorded. Based on the types of
5 behaviors observed in the testing of the instrument, two mouthing behaviors were selected for the
6 full study. These included: 1) tongue contacts object; 2) object in mouth. In addition four other
7 behaviors were included in an attempt to better describe the types of behaviors that would likely
8 result in soil ingestion: 1) hand touches ground; 2) child repulsed by object in mouth - tries to get
9 it out; 3) other person stops child's contact with object; and 4) child out of sight or view. In
10 addition to further characterize potential exposures to soil associated with the three types of
11 mouthing behaviors, six object categories were included to be used along with the three
12 mouthing behaviors. These were: 1) hand, finger, or thumb; 2) other body parts, including toes,
13 feet, arms; 3) natural materials, including dirt, sand, rocks, leaves; 4) toys and other objects,
14 including books, utensils, keys; 5) surfaces, including, window sills, floor, furniture, carpet; and
15 6) food or drink. An additional code was added to indicate whether an object was swallowed by
16 the child. The type of activity the child was engaged in during the observation period was also
17 recorded. In addition to mouthing behavior data, Davis (1995) collected information about how
18 long the child spent indoors and outdoors each day, and the general types of outdoor settings in
19 which the child played.
20 Mouthing behavior data were collected during a 4rday period. Both trained observers and
21 one parent observed the children .to record mouthing behavior data. Trained observers recorded
22 mouthing behavior data for 1 hour during active play time, while the parent recorded mouthing
23 behavior data for the first 15. minutes of that hour.
24 The basic measure of each type of mouthing activity derived from the observation form
25 , was the percent of time spent in that activity. This measure was defined as the percentage of the
26 total number of intervals observed that indicate such an activity took place. If there was no
27 activity in an interval, that interval was excluded. For tabulating the object categories, multiple
28 instances of the same object in a single interval were counted only once in that interval. Multiple
29 instances of different objects in a single interval were counted separately under each object
30 category.
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! Based on the mouthing behavior data collected in this study, EPA calculated that during
2 the period of observation (assumed to be 1 hour) the average mouthing activity was 6.2 minutes
3 and the average tongue activity was 0.70 minutes. It is important to note that this is based on one
4 hour of observation, hi order to estimate the overall mouthing activity in a day, one would have
5 to make some assumptions about the amount of time a child is involved in active play time in a
6 day. These values may also be underestimates because they assume that all the children in the
7 study were observed for one hour on each of the four days. If this were true, each child would
8 have a total of 960 intervals of observations (i.e., 3,600 seconds x intervals/15 seconds x 4 days).
9 The data show that the number of intervals of observation ranged from 80 to 840. It can be
10 concluded that some children were either observed for less than one hour or less than 4 days.
11 In order to compare the values estimated by Groot et al. (1998) whose work also used
12 time as a basis for measuring mouthing activity, it is necessary to multiply the Davis (1995)
13 hourly estimate by an estimate of how long the children are awake during the day. According to
14 Davis (1995) small children are awake approximately 8.9 hours per day for ages 0 to 48 months.
15 Based upon this estimate, the Davis (1995) findings translate into about 55 minutes per day of
16 mouthing activity and 6 minutes per day of tongue activity. The 55 minutes compares favorably
17 to the 37 minutes and 44 minutes estimated by Groot et al. (1998) for 3- to 6-month and 6- to 12-
18 month old children, respectively, but is significantly above the 16.4 minutes and 9.3 minutes
19 estimated for the 12- to 18-month and 18- to 36-month old children, respectively.
20 EPA also analyzed the mouthing behavior data for 86 children (43 males/43 females)
21 from the Davis (1995) study. Six children from the original sample size of 92 were excluded
22 from the analysis because no age information was provided. Total mouthing behavior included
23 both mouth and tongue contacts with hands, other body parts, surfaces, natural objects, and toys.
24 Eating events were excluded from the analysis. Statistical analysis was undertaken to determine
25 if significant differences existed between age and gender. Model results showed that there were
26 no associations between mouthing frequency and gender. However, a clear relationship was
27 observed between mouthing frequency and age. Two distinct groups could be identified:
28 male/female <24 months and male/female > 24 months. Children <24 months exhibited the
29 highest frequency of mouthing behavior with 76 ฑ 5 contacts/hr (n= 30 subjects; 106
30 observations). On the other hand, children > 24 months exhibited a lower frequency of mouthing
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1 behavior with 38 ฑ 3 contacts/hr (n= 56 subjects; 192 observations). These results suggest that
2 as children grow older, they are less likely to place objects into their mouths.
3 The Davis (1995) work has both strengths and weaknesses. The strengths of this work
4 are that it incorporates more children (e.g., 92) in the sample population than any of the other
5 literature reviewed. In addition, the research is very detailed in defining the parameters and
6 variables associated with mouthing behavior. The research also gathered information over four
7 days whereas most of the literature involved only one or two days of observation. Although the
8 research included the largest sample population of the reviewed literature, 92 sample points is
9 still a small number considering the wide variability associated with mouthing in children. The
10 random nature in which the population was selected probably provides a representative
11 population of the northwest U.S., but not the national population in general. The interval time of
12 15 seconds would also appear to be small and potentially easily skewed for those children
13 observed less than an hour. In addition, most other studies used observation times of 15 minutes
14 to continuous observation throughout waking hours.
15
6 6.3 RECOMMENDATIONS
17 Due to the paucity of the available research data, it is difficult to recommend with any
18 degree of certainty estimates for non-dietary ingestion. Table 6-3 summarizes the studies on
19 mouthing behavior that were described in this chapter. Table 6-4 summarizes the results of these
20 studies. As mentioned earlier, the studies presented use different units of reporting mouthing
21 behavior. If the assessor is interested in estimating exposures during macroactivities, then the
22 total amount of time engaged in mouthing behavior may be the unit of interest. Groot et al.
23 (1998) is the only study thus far that presents data for infants. These data, as well as the Davis
24 (1995) study, show that mouthing behavior decreases as children age. Data from both Groot et
25 al. (1998) and Davis (1995) for children between 3 to 60 months ranged from 9 min/day to 55
26 min/day with a weighted average of 46 min/day. If the assessor is interested in estimating
27 exposures to various microactivities, then the number of contacts with hands or objects per unit
28 of time may be the unit of interest. Reed et al. (1999) and Zartarian (1997) both studied hand-to-
29 mouth behavior. Although there are uncertainties with the results of these two studies due to
30 sample size, they are fairly consistent in their results. Based on these two studies, a value of 9
contacts/hour seems to be a reasonable estimate of hand-to-mouth behavior. Reed et al. (1999)
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1 also studied object-to-mouth frequency. Based on the Reed et al.- (1999) and the analysis of the
2 Davis (1995) data, total mouthing behavior, including hand-to-mouth as well as objects, ranged
3 from 26 contacts/hour (i.e., 9.5 (hand-to-mouth)+ 16.3 (object-to-mouth)) to 76 contacts/hour
4 with a weighted average of 45 contacts/hour.
5 The frequency of contact of finger-to-mouth (9.5 contacts/hr) greatly exceeds the 1.56
6 contacts/hr for fingers to mouth suggested by the U.S. EPA (1997) in their guidance for
7 calculating exposure to pesticides. The estimate of 9.5 contacts/hr is close to the 9 contacts/hr
8 estimated by Zartarian et al. (1997) for a study conducted using video taping as reported by Reed
9 et al. (1999). The agreement of the two studies suggests that the U.S. EPA (1997) value of 1.56
10 contacts/hr may significantly underestimate the non-dietary exposure route. Table 6-5 presents
11 the confidence ratings for the recommended values.
12
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1 6.4 REFERENCES FOR CHAPTER 6
2
3 Davis (1995). Soil Ingestion in Children with Pica (Final Report), EPA Cooperative Agreement CR 816334-01
4
5 Groot M., Lekkerkerk M., Steenbekkers L. (1998) Mouthing behavior of young children - an
6 observational study. H&C onderzoeksraport 3.
7
8 Gurunathan S., Robson M., Freeman N., Buckley B., Roy A., Meyer R., Bukowski L, and Lioy P. (1998)
9 Accumulation of chloropyrifos on residential surfaces and toys accessible to children. Environ.
10 Health Pers. 106(1 ):9-16.
11
12 Hubal, E.A.; Sheldon, L.S.; Burke, J.M.; McCurdy, T.R.; Berry, M.R.; Rigas, MX.; Zartarian, V.G.
13 (2000) Children's exposure assessment: A review of factors influencing children's exposure, and the
14 data available to characterize and assess that exposure. Prepared by U.S. Environmental Protection
15 Agency, National Exposure Research Laboratory, RTP, NC.
16
17 Reed K., Jimenez M., Freeman N., and Lioy P. (1999) Quantification of children's hand and mouthing
18 activities through a videotaping methodology. JEAEE. 9:513-520.
19
20 U.S. EPA (1997) Standard operating procedures (SOPs) for residential exposure assessment.
21 Washington, DC: Office of Pesticide Programs.
22
23 U.S. EPA, National Exposure Research Laboratory. (1999) Children's exposure assessment: A review
24 of factors influencing children's exposure, and the data available to characterize and assess that
J5 exposure.
6 '
27 Weaver V., Buckley T., and Groopman J. (1998) Approaches to environmental exposure assessment in
28 children. Environ. Health Pers. 106(3):827-831
29
30 Zartarian V., Ferguson A., and Leckie J. (1997) Quantified dermal activity data from a four-child pilot
31 field study. JEAEE 7(4):543-553.
32
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1 Table 6-1. Extrapolated Total Mouthing Times Minutes per Day (time awake)
2
3
Age (months)
3-
6-
12-
18-
6
12
18
36
No. Children
5
14
12
11
Mean
36.9
44
16.4
9.3
Standard Dev.
19.1
44.7
18.2
9.8
Minimum
14.5
2.4
0
0
Maximum
67
171.5
53.2
30.9
8
9
10 Note: The object most mouthed in all age groups in the fingers except for the 6-12 month group which
11 mostly mouthed on toys.
12
13 Source: Groot et al. (1998)
14
15
16
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1
2
ป 3
4
5
6
7
8
9
10
11
12
13
14
15
16
Table
Variable
Clothing
Dirt
Hand
Hand to mouth
Object
Object to mouth
Other
Smooth surface
Textured surface
Source: Reed et al. (1999)
6-2. Frequency of Contact, by Contact Variable Contacts per Hour
Mean
66.6
11.4
21.1
9.5
122.9
16.3
82.9
83.7
22.1
Median
65
0.3
14.2
8.5
118.7
3.6
64.3
80.2
16.3
Minimum
22.8
0
6.3
0.4
56.2
0
. 8.3
13.6
0.2
Maximum
129.2
146.3
116.4
25.7
312
86.2
243.6
190.4
68.7
90th Percentile
103.3
56.4
43.5
20.1
175.8
77.1
199.6
136.9
52.2
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1
2
3
4
Study
Grootetal. 1998
Table 6-3. Summary of Studies on Mouthing Behavior
Population Size Population Studies
42 3-36 months in Netherlands
6
7
8
9
10
Reedetal. 1999
Zartarian 1997
Davis 1995
30
4
92
children from well educated
parents
20 children 3-6 years
10 children 2-5 years
Day care and residential settings
2.5-4.2 years
children of farm workers
10-60 months
Washington State
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1
2
3
4
5
6
7
Table 6-4. Summary of Mouthing Frequency Data
Age (months)
3-6
6-12
12-18
18-36
Mouthing Frequency/Time
1 m in/day
44 min/day
1 6 min/day
9 min/day
Population Size
5
14
12
11
Reference
Grootetal. 1998
10
11
12
13
14
15
16
2-6 years
2.5-4.2 years
10-60
<24
>24
9.5 contacts/hr (hand to mouth) 30
16.3 contacts/hr (object to mouth)
9 contacts/hr
55 min/day
76 ฑ5 contacts/hr
38 ฑ3 contacts/hr
92
30
56
Reedetal. 1999
Zartarian 1997
EPA analysis of
Davis 1995
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1
2
3
4 "
5
6
7
8
9
10
11
'12
13
14
15
16
17
18
19
20
21
22
23
Table 6-5. Confidence in Mouthing Behavior Recommendations
Considerations
Study Elements
Peer Review
Accessibility
Reproducibility
Focus on factor of Interest
Data pertinent to U.S.
Primary data
Currency
Adequacy of data collection
period
Validity of Approach
Representativeness of the
population
Characterization of variability
Lack of bias in study design
Measurement error
Other Elements
Number of studies
Agreement between researchers
Overall Rating
Rationale
Three of the studies are from peer review journals, one
from a contractor's report to EPA
Studies in journals have wide circulation.
Contractor's report only available through EPA
Cannot reproduce the data unless raw data are provided.
Studies focused on mouthing behavior as well as other
hand contacts.
Studies were conducted in the U.S.
Analyses were done on primary data. EPA did the
analysis of the raw data from David et al. 1995.
Recent studies were evaluated
Data were collected for a period of several days, not
enough to represent seasonal variations.
Measurements were made by observation methods. Both
surveys and videotaping were used. Videotaping
techniques may be more reliable, but resource intensive.
An effort was made to consider age and gender (in the
Davis study), but sample size was too small.
An effort was made to consider age and gender, data for
infants is fairly limited.
Subjects were selected from volunteers.
Measuring children's behavior is difficult and somewhat
subjective and depends on the experience of the observer.
Four studies were evaluated
There is general agreement among the researchers.
Although there are four studies, they have very small
sample size, variability in the population cannot be
assessed. Variation in behavior due to seasons cartnot be
evaluated. Measuring children's behavior is difficult.
| Rating
Medium
Medium
Medium
High
High
High
High
Medium
Medium
Low
Low
Medium
Medium
Medium
High
Low/Medium
24
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1 7. INHALATION ROUTE
2
3 7.1 INTRODUCTION
4 This chapter presents data and recommendations for inhalation rates that can be used to
5 assess children's exposure to contaminants in air. Children may be more highly exposed to
6 environmental toxicants through inhalation routes than adults. Infants and young children have
7 a higher resting metabolic rate and rate of oxygen consumption per unit body weight than adults
8 because they have a larger cooling surface per unit body weight and because they are growing
9 rapidly. The oxygen consumption of a resting infant aged between one week and one year is 7
10 ml/kg body weight per minute. The rate for an adult under the same conditions is 3-5 ml/kg per
11 minute (WHO 1996). Thus, the volume of air passing through the lungs of a resting infant is
12 twice that of a resting adult under the same conditions and therefore twice as much of any
13 chemical in the atmosphere could reach the lungs of an infant. The recommended inhalation
14 rates for children are summarized in Section 7.3.
15
16 7.2 INHALATION RATE STUDIES
17 Linn et al. (1992) - Documentation of Activity Patterns in "High-Risk" Groups Exposed
18 to Ozone in the Los Angeles Area - Linn et al. (1992) conducted a study that estimated the
19 inhalation rates for "high-risk" subpopulation groups exposed to ozone (O3) in their daily
20 activities in the Los Angeles area. The population surveyed consisted of several panels of both
21 adults and children. The panels consisting of children included: Panel 2: 17 healthy elementary
22 school students (5 males, 12 females, ages 10-12 years); Panel 5:19 healthy high school students
23 (7 males, 12 females, ages 13-17 years); Panel 6: 13 young asthmatics (7 males, 6 females, ages
24 11-16 years).
25 Initially, a calibration test was conducted, followed by a training session. Finally, a field
26 study was conducted which involved subjects' collecting their own heart rate and diary data.
27 During the calibration tests, ventilation rate (VR), breathing rate, and heart rate (HR) were
28 measured simultaneously at each exercise level. From the calibration data an equation was
29 developed using linear regression analysis to predict VR from measured HR (Linn et al., 1992).
ฃp In the field study, each subject recorded in diaries: their daily activities, change in
locations (indoors, outdoors, or in a vehicle), self-estimated breathing rates during each
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1 activity/location, and time spent at each activity/location. Healthy subjects recorded their HR
2 once every 60 seconds, Asthmatic subjects recorded their diary information once every hour
3 using a Mean Watch. Subjective breathing rates were defined as slow (walking at their normal
4 pace); medium (faster than normal walking); and fast (running or similarly strenuous exercise).
5 Table 7-1 presents the calibration and field protocols for self-monitoring of activities for each
6 subject panel.
7 Table 7-2 presents the mean VR, the 99th percentile VR, and the mean VR at each
8 subjective activity level (slow, medium, fast). The mean VR and 99th percentile VR were
9 derived from all HR recordings (that appeared to be valid) without considering the diary data.
10 Each of the three activity levels was determined from both the concurrent diary data and HR
11 recordings by direct calculation or regression (Linn et al., 1992). Linn et al. (1992) reported that
12 the diary data showed that most individuals spent most of their time (in a typical day) indoors at
13 slow activity level. During slow activity, asthmatic subjects had higher VRs than healthy
14 subjects, (Table 7-2). Also, Linn et al. (1992) reported that in every panel, the predicted VR
15 correlated significantly with the subjective estimates of activity levels.
16 A limitation of this study is that calibration data may overestimate the predictive power of
17 HR during actual field monitoring. The wide variety of exercises in everyday activities may
18 result in greater variation of the VR-HR relationship than calibrated. Another limitation of this
19 study is the small sample size of each subpopulation surveyed. An advantage of this study is that
20 diary data can provide rough estimates of ventilation patterns which are useful in exposure
21 assessments. Another advantage is that inhalation rates were presented for both healthy and
22 asthmatic children.
23 Spier et al. (1992) - Activity Patterns in Elementary and High School Students Exposed
24 To Oxidant Pollution - Spier et al. (1992) investigated activity patterns of 17 elementary school
25 students (10-12 years old) and 19 high school students (13-17 years old) in suburban Los Angeles
26 from late September to October (oxidant pollution season). Calibration tests were conducted in
27 supervised outdoor exercise sessions. The exercise sessions consisted of 5 minutes for each: rest,
28 slow walking, jogging, and fast walking. HR and VR were measured during the last 2 minutes of
29 each exercise. Individual VR and HR relationships for each individual were determined by
30 fitting a regression line to HR values and log VR values. Each subject recorded their daily
31 activities, change in location, and breathing rates in diaries for 3 consecutive days. Self-
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I estimated breathing rates were recorded as slow (slow walking), medium (walking faster than
2 normal), and fast (running). HR was recorded during the 3 days once per minute by wearing a
3 Heart Watch. VR values for each self-estimated breathing rate and activity type were estimated
4 from the HR recordings by employing the VR and HR equation obtained from the calibration
5 tests.
6 The data presented in Table 7-3 represent HR distribution patterns and corresponding
7 predicted VR for each age group during hours spent awake. At the same self-reported activity
8 levels for both age groups, inhalation rates were higher for outdoor activities than for indoor
9 activities. The total hours spent indoors by high school students (21.2 hours) were higher than
10 for elementary school students (19.6 hours). The converse was true for outdoor activities;
11 2.7 hours for high school students, and 4.4 hours for elementary school students (Table 7-4).
12 Based on the data presented in Tables 7-3 and 7-4, the average activity-specific inhalation rates
13 for elementary (10-12 years) and high school (13-17 years) students were calculated in Table 7-5.
14 For elementary school students, the average daily inhalation rates (based on indoor and outdoor
15 locations) are 15.8 mVday for light activities, 4.62 m3/day for moderate activities, and
16 0.98 mVday for heavy activities. For high school students the daily inhalation rates for light,
17 moderate, and heavy activities are estimated to be 16.4 m3/day, 3.1 m3/day, and 0.54 m3/day,
18 respectively (Table 7-5).
19 A limitation of this study is the small sample size. The results may not be representative
20 of all children in these age groups. Another limitation is that the accuracy of the self-estimated
21 breathing rates reported by younger age groups is .uncertain. This may affect the validity, of the
22 data set generated. An advantage of this study is that inhalation rates were determined for
23 children and adolescents. These data are useful in estimating exposure for the younger
24 population.
25 Adams (1993) Measurement of Breathing Rate and Volume in Routinely Performed
26 Daily Activities - Adams (1993) conducted research to accomplish two main objectives:
27 (1) identification of mean and ranges of inhalation rates for various age/gender cohorts and
28 specific activities; and (2) derivation of simple linear and multiple regression equations used to
29 predict inhalation rates through other measured variables: breathing frequency (fB) and oxygen
30 consumption (V02). A total of 160 subjects participated in the primary study. For children, there
Fl were two age dependent groups: (1) children 6 to 12.9 years old, (2) adolescents between 13 and
June 2000 7-3 DRAFT-DO NOT QUOTE OR CITE
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1 18.9 years old, (Adams, 1993). An additional 40 children from 6 to 12 years old and 12 young
2 children from 3 to 5 years old were identified as subjects for pilot testing purposes (Adams,
3 1993).
4 Resting protocols conducted in the laboratory for all age groups consisted of three phases
5 (25 minutes each) of lying, sitting, and standing. They were categorized as resting and sedentary
6 activities. Two active protocols, moderate (walking) and heavy (jogging/ running) phases, were
7 performed on a treadmill over a progressive continuum of intensities made up of 6 minute
8 intervals, at 3 speeds, ranging from slow to moderately fast. All protocols involved measuring
9 VR, HR, fB (breathing frequency), and V0, (oxygen consumption). Measurements were taken in
10 the last 5 minutes of each phase of the resting protocol, and the last 3 minutes of the 6 minute
11 intervals at each speed designated in the active protocols.
12 In the field, all children completed spontaneous play protocols, while the older adolescent
13 population (16-18 years) completed car driving and riding, car maintenance (males), and
14 housework (females) protocols.
15 During all activities in either the laboratory or field protocols, IR for the children's group
16 revealed no significant gender differences. Therefore, IR data presented in Appendix
17 Tables 7A-1 and 7A-2 were categorized as young children, chiidren (no gender) by activity levels
18 (resting, sedentary, light, moderate, and heavy). These categorized data from the Appendix
19 tables are summarized as IR in mVhr in Tables 7-6 and 7-7. The laboratory protocols are shown
20 in Table 7-6. Table 7-7 presents the mean inhalation rates by group and activity levels (light,
21 sedentary, and moderate) in field protocols. Accurate predictions of IR across all population
22 groups and activity types were obtained by including body surface area (BSA), HR, and fB in
23 multiple regression analysis (Adams, 1993). Adams (1993) calculated BSA from measured
24 height and weight using the equation:
25
BSA = Height^0"425) x Weight^0'425) x 71.84 (7*1)
26
27
28 A limitation associated with this study is that the population does not represent the
29 general U.S. population. Also, the classification of activity types (i.e., laboratory and field
June 2000 7-4 DRAFT-DO NOT QUOTE OR CITE
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1 protocols) into activity levels may bias the inhalation rates obtained for various age/gender
2 cohorts. The estimated rates were based on short-term data and may not reflect long-term
3 patterns.
4 Layton (1993) - Metabolically Consistent Breathing Rates for Use in Dose Assessments -
5 Layton (1993) presented a new method for estimating metabolically consistent inhalation rates
6 for use in quantitative dose assessments of airborne radionuclides. Generally, the approach for
7 estimating the breathing rate for a specified time frame was to calculate a time-weighted-average
8 of ventilation rates associated with physical activities of varying durations (Layton, 1993).
9 However, in this study, breathing rates were calculated based on oxygen consumption associated
10 . with energy expenditures for short (hours) and long (weeks and months) periods of time, using
11 the following general equation to calculate energy-dependent inhalation rates:
12
13 VE = E x H x VQ (7-2)
14 where:
15 VE = ventilation rate (L/min or mVhr);
E = energy expenditure rate; [kilojoules/minute (KJ/min) or
17 megajoules/hour (MJ/hr)];
18 H = volume of oxygen [at standard temperature and pressure, dry air
19 (STPD) consumed in the production of 1 kilojoule (KJ) of energy
20 expended (L/KJ or m3/MJ)]; and
21 VQ = ventilatory equivalent (ratio of minute volume (L/min) to oxygen
22 uptake (L/min)) unitless.
23
24 Three alternative approaches were used to estimate daily chronic (long term) inhalation
25 rates for different age/gender cohorts of the U.S. population using this methodology.
26
27 , First Approach
28 Inhalation rates were estimated by multiplying average daily food energy intakes for
29 different age/gender cohorts, volume of oxygen (H), and ventilatory equivalent (VQ), as shown
in the equation above. The average food energy intake data (Table 7-8) are based on
June 2000 7-5 DRAFT-DO NOT QUOTE OR CITE
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1 approximately 30,000 individuals and were obtained from the USDA 1977-78 Nationwide Food
2 Consumption Survey (USDA-NFCS). The food energy intakes were adjusted upwards by a
3 constant factor of 1.2 for all individuals 9 years and older (Layton, 1993). This factor
4 compensated for a consistent bias in USDA-NFCS attributed to under reporting of the foods
5 consumed or the methods used to ascertain dietary intakes. Layton (1993) used a weighted
6 average oxygen uptake of 0.05 L O2/KJ which was determined from data reported in the 1977-78
7 USDA-NFCS and the second National Health and Nutrition Examination Survey (NHANES II).
8 The survey sample for NHANES II was approximately 20,000 participants. The ventilatory
9 equivalent (VQ) of 27 used was calculated as the geometric mean of VQ data that were obtained
10 from several studies by Layton (1993).
11 The inhalation rate estimation techniques are shown in footnote (a) of Table 7-9.
12 Table 7-9 presents the daily inhalation rate for each age/gender cohort. The highest daily
13 inhalation rates were reported for children between the ages of 6-8 years (10 mVday), for males
14 between 15-18 years (17 nrVday), and females between 9-11 years (13 nrVday). Inhalation rates
15 were also calculated for active and inactive periods for the various age/gender cohorts.
16 The inhalation rate for inactive periods was estimated by multiplying the basai metabolic
17 rate (BMR) times the oxygen uptake (H) times the VQ. BMR was defined as "the minimum
18 amount of energy required to support basic cellular respiration while at rest and not actively
19 digesting food" (Layton, 1993). The inhalation rate for active periods was calculated by
20 multiplying the inactive inhalation rate by the ratio of the rate of energy expenditure during
21 active hours to the estimated BMR. This ratio is .presented as F in Table 7-9. These data for
22 active and inactive inhalation rates are also presented in Table 7-9. For children, inactive and
23 active inhalation rates ranged between 2.35 and 5.95 nrVday and 6.35 to 13.09 nrYday,
24 respectively.
25 Second Approach
26 Inhalation rates were calculated by multiplying the BMR of the population cohorts times
27 A (ratio of total daily energy expenditure to daily BMR) times H times VQ. The BMR data
28 obtained from the literature were statistically analyzed and regression equations were developed
29 to predict BMR from body weights of various age/gender cohorts (Layton, 1993). The statistical
30 data used to develop the regression equations are presented in Appendix Table 7A-3. The data
31 obtained from the second approach are presented in Table 7-10. Inhalation rates for children
June 2000 .7-6 DRAFT-DO MOT QUOTE OR CITE
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(6 months - 10 years) ranged from 7.3-9.3 m3/day for male and 5.6 to 8.6 mVday for female
children, and for older children (10-18 years), inhalation rates were 15 mVday for males and 12
3 m3/day for females. These rates are similar to the daily inhalation rates obtained using the first
4 approach. Also, the inactive inhalation rates obtained from the first approach are lower than the
5 inhalation rates obtained using the second approach. This may be attributed to the BMR
6 multiplier employed in the equation of the second approach to calculate inhalation rates.
7 Inhalation rates were also obtained for short-term exposures for various age/gender
8 cohorts and five energy-expenditure categories (rest, sedentary, light, moderate, and heavy).
9 BMRs were multiplied by the product of MET, H, and VQ. The data obtained for short term
10 exposures are presented in Table 7-11.
11 The major strengths of the Layton (1993) study are that it obtains similar results using
12 three different approaches to estimate inhalation rates in different age groups and that the
13 populations are large, consisting of men, women, and children. Explanations for differences in
14 results due to metabolic measurements, reported diet, or activity patterns are supported by
15 observations reported by other investigators in other studies. Major limitations of this study are
that activity pattern levels estimated in this study are somewhat subjective, the explanation that
17 activity pattern differences is responsible for the lower level obtained with the metabolic
18 approach (25 percent) compared to the activity pattern approach is not well supported by the
19 data, and different populations were used in each approach which may introduce error.
20
21 7.3 RECOMMENDATIONS
22 The recommended inhalation rates for children are based on the studies described in this
23 chapter. Different survey designs and populations were utilized in the studies described in this
24 Chapter. Excluding the study by Layton (1993), the population surveyed in all of the studies
25 described in this report were limited to the Los Angeles area. This regional population may not
26 represent the general U.S. population and may result in biases. However, based on other aspects
27 of the study design, these studies were selected as the basis for recommended inhalation rates.
28 The selection of inhalation rates to be used for exposure assessments depends on the age
29 of the exposed population and the specific activity levels of this population during various
30 exposure scenarios. The confidence ratings and recommended inhalation rates are presented in
Tables 7-12 and 7-13, respectively. Based on the study results from Layton (1993), the
June 2000 7-7 DRAFT-DO NOT QUOTE OR CITE
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1 recommended daily inhalation rate for infants (children less than 1 yr), during long-term dose
2 assessments is 4.5 nrVday. For children 1-2 years old, 3-5 years old, and 6-8 years old, the
3 recommended daily inhalation rates are 6.8 mVday, 8.3 mVday, and 10 m3/day, respectively.
4 Recommended values for children aged 9-11 years are 14 m3/day for males and 13 mVday for
5 females. For children aged 12-14 years and 15-18 years, the recommended values are shown in
6 Table 7-13.
7 Recommended short-term inhalation rates for children aged 18 years and under are also
8 summarized in Table 7-13. The short-term inhalation rates were calculated by averaging the
9 inhalation rates for each activity level from the various key studies (Table 7-14). The
10 recommended average hourly inhalation rates are as follows: 0.3 mVhr during rest; 0.4 m3/Tir for
11 sedentary activities; 1.0 mVhr for light activities; 1.2 nrYhr for moderate activities: and 1.9 m3/hr
12 for heavy activities. The recommended short-term exposure data also include infants (less than
13 lyr). . . .
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1 7.4 REFERENCES FOR CHAPTER 7
2
"3 Adams, W.C. (1993) Measurement of breathing rate and volume in routinely performed daily activities, Final
4 Report. California Air Resources Board (CARB) Contract No. A033-205. June 1993. 185 pgs.
6 Basiotis, P.P.; Thomas, R.G.; Kelsay, J.L.; Mertz, W. (1989) Sources of variation in energy intake by men and
7 women as determined from one years daily dietary records. Am. J. Ciin. Nutr. 50:448-453.
8
9 Layton, D.W. (1993) Metabolically consistent breathing rates for use in dose assessments. Health Physics 64( 1 ):23-
10 36.
11
12 Linn, W.S.; Shamoo. D.A.; Hackney, J.D. (1992) Documentation of activity patterns in "high-risk" groups exposed
13 to ozone in the Los Angeles area. In: Proceedings of the Second EPA/A WM A Conference on
14 Tropospheric Ozone, Atlanta, Nov. 1991. pp. 701 -712. Air and Waste Management Assoc., Pittsburgh,
15 PA.
16
17 Spier, C.E.; Little, D.E.; Trim, S.C.; Johnson; T.R.; Linn, W.S.; Hackney, J.D. (1992) Activity patterns in
18 elementary and high school students exposed to oxidant pollution. J. Exp. Anal. Environ Epid 2(3):2?7-
19 293.
20
21 WHO (1986) Principles for evaluating health risks from chemicals during infancy and early chiIdhood: the need for
22 a special approach. Environmental Health Criteria 59. World Health Organization, International
23 Programme on Chemical Safetv.
24
25
26
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1
2
3
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
Table 7-1. Calibration And Field Protocols For Self-monitoring of Activities
Grouped by Subject Panels
Panel
Calibration Protocol
Field Protocol
Panel 2 - Healthy Elementary
School Students - 5 male,
12 female, age 10-12
Panel 3 - Healthy High School
Students - 7 male, 12 female,
age 13-17
Outdoor exercises each consisted of
20 minute rest, slow walking,
jogging and fast walking
Outdoor exercises each consisted of
20 minute rest, slow walking,
jogging and fast walking
Panel 6 - Young Asthmatics - 7 Laboratory exercise tests on
male, 6 female, age i 1-16 bicycles and treadmills
Saturday, Sunday and Monday (school
day) in early autumn; HR recordings
and activity diary during waking hours
and during sleep.
Same as Panel 2, however, no HR
recordings during sleep for most
subjects.
Similar to Panel 4, summer monitoring
for 2 successive weeks, including 2
controlled exposure studies with few
or no observable respiratory effects.
Source: Linn etal., 1992
Table 7-2. Subject Panel Inhalation Rates by Mean VR, Upper
Percentiles, And Self-estimated Breathing Rates
Inhalation Rates (mVhr)
N' Mean VR
(mVhr)
Panel
Healthv
2 - Elementary School Students 1 7 0.90
3 - High School Students 19 0.84
Asthmatics
6 - Elementary and. High School 13 1.20
Students
99th Mean VR at Activity Levels
Percentile VR (m3/hr)b
Slow
1.98 0.84
2.22 0.78
2.40 120
Medium Fast
0.96 1.14
1.14 1.62
1.20 1.50
'Number of individuals in each survey panel.
bSome subjects did not report medium and/or fast activity. Group means were calculated from individual means
(i.e., give equal weight to each individual who recorded any time at the indicated activity level).
Source: Linn et al. (1992).
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1
1
F3
4
5
6
7
8
9
10
11
12
J3
|4
15
16
17
18
19
20
21
22 .
23
24
25
26
27
28
29
30
31
32
33
34
Table 7-3. Distribution of Predicted Intake Rates by Location
For Elementary And
And Activity Levels
High School Students
Inhalation Rates (m3/hr)
Percentile Rankings*
Age (yrs)
10-12
13-17
Student
Elc
(n"=l7)
HSC
(n<=19)
"Recorded time averaged
over 72-hr.
periods.
Location
Indoors
Outdoors
Indoors
Outdoors
Activity %
Level
slow
medium
fast
slow
medium
fast
slow
medium
fast
slow
medium
fast
Recorded
Time"
49.6
23.6
2.4
8.9
11.2
4.3
70.7 .
10.9
i.4
8.2
7.4
1.4
about 23 hr per elementary school student
bGeometric means closely approximated 50th percentiles; geometric
1.5-1.8
Mean ฑ SD
0.84 ฑ
0.96 ฑ
1.02ฑ
0.96 ฑ
1.08ฑ
l.I4ฑ
0.78 ฑ
0.96 ฑ
1.26ฑ
0.96 ฑ
1.26ฑ
1.44ฑ
0.36
0.42
0.60
0.54
0.48
0.60
0.36
0.42
0.66
0.48
0.78
1.08
and 33 hr. per
l"
0.18
0.24
0.24
0.36
0.24
0.48
0.30
0.42
0.54
0.42
0.48
0.48
high school
50'"
0.78
0.84
0.84
0.78
0.96
0.96
0.72
0.84
1.08
0.90
1.08
1.02
99.9th
2.34
2.58
3.42
4.32
3.36
3.60
3.24
4.02
6.84C
528
5.70
5.94
student.
standard deviations were 1 .2- 1 .3
for HR,
for VR.
SEL = elementary school
student; HS =
high school student.
*N = number of students that participated in survey.
'Highest
Source:
single value.
Spier etal( 1992).
Table
7-4. Average
Hours Spent Per Day in a Given Location
and Activity
Level For Elementary (EL) and High School (HS) Students
Student
Activity Level
(EL'.n'-l?;
N<=19)
EL
EL
HS
HS
"Elementary
HS",
school (EL)
Total
Time Spent
(hrs/day)
Location
Indoor
Outdoor
Indoor
Outdoor
Slow
16.3
2.2
19.5
1.2
Medium
2.9
1.7
1.5
1.3
. Fast
0.4
0.5
0.2
0.2
19.6
4.4
21.2
2.7
students were between 10-12 years old.
bHigh school (HS) students were between 13-17 years old.
TV! corresponds to number of school students.
Source: Spier et al. (1992).
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1
2
3
4
5
6
7
8
9
10
11
12
13
Table 7-5. Distribution Patterns of Daily Inhalation
Rates For Elementary (EL) And High School (HS)
Students Grouped by Activity Level
Percentile Rankings
Students
EL
(n<=17)
EL
HS
(n=19)
HS
Age Mean IRb
(yrs) Location Activity type1 (nvVday) 1st
10-12 Indoor Light 13.7 2.93
Moderate 2.8 .0.70
Heavy 0.4 0.096
Outdoor Light 2.1 0.79
Moderate 1.84 0.41
Heavy 0.57 0-24
13-17 Indoor Light 15.2 5.85
Moderate 1.4 0.63
Heavy 0.25 0.11
Outdoor Light 1.15 0.50
Moderate 1.64 0.62
Heavy 0.29 0.096
50th
12.71
2.44
0.34
1.72
1.63
0.48
14.04
1.26
0.22
1.08
1.40
0.20
99.9th
38.14
7.48
1.37
9.50
5.71
1.80
63.18
6.03
1.37
6.34
7.41
1.19
14
15
16
17
18
19
20
21
22
*For this report, activity type presented in Table 7-2 was redefined as light activity for slow, moderate activity
for medium, and heavy activity for fast.
"Daily inhalation rate was calculated by multiplying the hours spent at each activity level (Table 7-4) by the
corresponding inhalation rate (Table 7-3).
'Number of elementary (EL) and high school students (HS).
Source: Adapted from Spier et al. (1992) (Generated using data from Tables 7-3 and 7-4).
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Table 7-6. Summary of Average Inhalation Rates (M3/hr) by Age Group And Activity Levels
For Laboratory Protocols
4
5
6
Age Group
Young Chiidrenf
Children11
Resting3
0.37
0.45
Sedentary13
0.40
0.47
Light*
0.65
0.95
Moderated
DNPง
1.74
Heavy*
DNP
2.23
7 'Resting defined as lying (see Appendix Table 7A-1 for original data).
8 bSedentary defined as sitting and standing (see Appendix Table 7A-1 for original data).
9 'Light defined as walking at speed level 1.5 - 3.0 mph (see Appendix Table 7A-1 for original data).
10 ''Moderate defined as fast walking (3.3 - 4.0 mph) and slow running (3.5 - 4.0 mph) (see Appendix Table 7A-1
11 for original data).
12 'Heavy defined as fast running (4.5 - 6.0 mph) (see Appendix Table 7A-1 for original data).
13 'Young children (both genders) 3 - 5.9 yrs old.
14 SDNP. Group did not perform this protocol or N was too small for appropriate mean comparisons. All young
15 children did not run.
16 kChildren (both genders) 6 - 12.9 yrs old.
17
18 Source: Adapted from Adams (1993).
19
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1
2
3
Table 7-7. Summary of Average Inhalation Rates (MVhr) by
Age Group And Activity Levels in Field Protocols
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
Age Group
Young Children
Children1"
Light3
DNPe
DNP
Sedentary1"
DNP
DNP
Moderate0
0.68
1.07
"Light activity was defined as car maintenance (males), housework (females), and yard work (females) (see
Appendix Table 7A-2 for original data).
"Sedentary activity was defined as car driving and riding (both genders) (see Appendix Table 7A-2 for original
data).
'Moderate activity was defined as mowing (males); wood working (males); yard work (males); and play
(children) (see Appendix Table 7A-2 for original data).
dYoung children (both genders) = 3 - 5.9 yrs old.
'DNP. Group did not perform this protocol or N was too small for appropriate mean comparisons.
Children (both genders) = 6 -12.9 yrs old.
Source: Adams (1993).
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1
>
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
J9
Table 7-8.
Cohort/Age
(years)
Children
Under 1
1 to 2
3 to 5
6 to 8
Males
9 to 11
12 to 14
15 to 18
Females
9 to 11
12 to 14
15 to 18
Comparisons of Estimated Basal Metabolic Rates (BMR) With Average Food-energy Intakes For
Individuals Sampled in The 1977-78 NFCS
Body Weight
kg
7.6
13
18
26
36
50
66
36
49
56
"O "Calculated from the appropriate
21
22
23
24
25
26
27
28
MJ d"lb
1.74
3.08
3.69
4.41
5.42
6.45
7.64
4.91
5.64
6.03
BMRa
kcal d'lc
416
734
881
1053
1293
1540
1823
1173
1347
1440
Energy Intake (EFD)
MJd*1
3.32
5.07
6.14
7.43
8.55
9.54
10.8
7.75
7.72
7.32
age and gender-based BMR equations given
kcal d'1
793
1209
1466
1774
2040
2276
2568
1849
1842
1748
in Appendix Table
Ratio
EFD/BMR
1.90
1.65
1.66
1.68
1.58
1.48
1.41
1.58
1.37
1.21
7A-3.
bMJ d'1 - mega joules/day
ekcal d'1 - kilo
calories/day
Source: Layton(1993).
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f
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
Table 7-9. Daily Inhalation Rates Calculated From
Food-energy Intakes
MET" Value
Cohort/Age
(years)
Children
<\
1 -2
3-5
6-8
Males
9-11
12- 14
15-18
Females
9-11
12-14
15-18
Ld
1
2
3
3
3
3
4
3
3
4
Daily Inhalation Rate3
(mVday)
4.5
6.8
8.3
10
14
15
17
13
12
12
(h)Sieep
(h)
11
11
10
10
9
9
8
9
9
8
Ae
1.9
1.6
1.7
1.7
1.9
1.8
1.7
1.9
1.6
1.5
Ff
2.7
2.2
2.2
2.2
2.5
2.2
2.1
2.5
2.0
1.7
Inhalation Rates
Inactive0
(mVday)
2.35
4.16
4.98
5.95
7.32
8.71
10.31
6.63
7.61
8.14
Active0
(mVday)
6.35
9.15
10.96
13.09
18.3
19.16
21.65
16.58
15.20
13.84
'Daily inhalation rate was calculated by multiplying the EFD values (see Table 7-10) by H x VQ x
(m3 1,000 L'1) for subjects under 9 years of age and by 1.2 x H x VQ x (m3 1,000 L'1) (for subjects 9 years of
age and older (see text for explanation).
Where:
EFD = Food energy intake (Kcal/day) or (MJ/day)
H = Oxygen uptake = 0.05 LO,/KJ or 0.21 LO,/Kca!
VQ = Ventilation equivalent = 27 = geometric mean of VQs (unitiess)
bMET = Metabolic equivalent
'Inhalation rate for inactive periods was calculated as BMR x H x VQ x (d 1,440 min'1) and for active periods by
multiplying inactive inhalation rate by F (See footnote f); BMR values are from Table 7-10.
Where:
BMR = Basal metabolic rate (MJ/day) or (kg/hr)
dL is the number of years for each age cohort.
eFor individuals 9 years of age and older, A was calculated by multiplying the ratio for EFD/BMR (unitiess)
(Table 7-10) by the factor 1.2 (see text for explanation).
fF = (24A - S)/(24 - S) (unitiess), ratio of the rate of energy expenditure during active hours to the estimated
BMR (unitiess)
Where:
S = Number of hours spent sleeping each day (hrs)
Source: Layton (1993).
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Table 7-10. Daily Inhalation Rates Obtained From The Ratios
Of Total Energy Expenditure to Basal Metabolic Rate (BMR)
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Gender/Age
(yrs)
Male
0.5 - <3
3-<10
10-<18
Female
0.5 - <3
3-
-------
1
3
4
7
8
9
.10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Table 7-11. Inhalation Rates For Short-term Exposures
Rest
Activity Type
Sedentary Liaht Moderate
Heavy
MET (BMR Multiplier)
Gender/Age
(vrs)
Male
0.5 - <3
3-<10
10-<18
Female
0.5 - <3
3-<10
in-7n
1
1.2
2C
4d
10e
Inhalation Rate (m3/hr)f-s
0.19
0.24
0.38
0.14
0.23
n T?
0.23
0.29
0.45
0.17
0.27
n iX
0.38
0.49
0.78
0.29
0.45
Dfifi
0.78
0.96
1.50
0.60
0.90
1 ?fi
1.92
2.40
3.78
1.44
2.28
1 18
'Body weights were based on average weights for age/gender cohorts of the U.S. population
"The BMRs for the age/gender cohorts were calculated using the respective body weights and the BMR
equations (Appendix Table 7A-3).
cRange of 1.5-2.5.
"Range of 3-5.
'Range of >5 - 20.
the inhalation rate was calculated by multiplying BMR (MJ/day) x H (0:05 L/KJ) x MET x VQ (27) x
(d/l,440min)
Kfriginal data were presented in L/min. Conversion to mVhr was obtained as follows:
Source: Layton(1993).
60 min
hr
1000L rain
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_
1
2
3
4
5
6
7
8
9
10
11
12
13
14
^5
^F
17
18
19
20
21
22
23
24
25
26
27
Table 7- 12.
Considerations
Study Elements
Peer Review
Accessibility
Reproducibiiity
Focus on factor of interest
Data pertinent to U.S.
Primary data
Currency
* Adequacy of data collection
period
Validity of approach
Representativeness of the
population
Characterization of variability
Lack of bias in study design
Measurement error
Other Elements
Number of studies
ซ Agreement between researchers
Overall Rating
June 2000
Confidence in Inhalation Rate Recommendations
Rationale
Studies are from peer reviewed journal articles and an
EPA peer reviewed report.
Studies in journals have wide circulation.
EPA reports are available from the National Technical
Information Service.
Information on questionnaires and interviews were not
provided.
Studies focused on ventilation rates and factors
influencing them.
Studies conducted in the U.S.
Both data collection and re-analysis of existing data
occurred.
Recent studies were evaluated.
Effort was made to collect data overtime.
Measurements were made by indirect methods.
An effort has been made to consider age and gender, but
not systematically. Sample size was too small.
An effort has been made to address age and gender, but
not systematically.
Subjects were selected randomly from volunteers and
measured in the same way.
Measurement error is well documented by statistics, but
procedures measure factor indirectly.
Five key studies and six relevant studies were evaluated.
There is general agreement among researchers using
different experimental methods.
Several studies exist that attempt to estimate inhalation
rates according to age, gender and activity.
Rating
High
High
Medium
High
High
Medium
High
High
Medium
Medium
High
High
Medium
High
Medium
7-19 DRAFT-DO NOT QUOTE OR CITE
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1
2
Table 7-13. Summary of Recommended Values For inhalation
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Population
Mean Upper Percentile
Long-term Exposures
Infants
<1 year
Children
1-2 years
3-5 years
6-8 years
9-1 1 years
males
females
1 2- 14 years
maies
females
15-18 years
males
females
4.5 mVday
6.8 mVday
8.3 mVday
1 0 mVday
14 mVday
13m3/day
15 mVday
12m3/day
I7m3/day .
12m3/day
Short-term Exposures
Children (18 years and under)
Rest
Sedentary Activities
Light Activities
Moderate Activities
Heavy Activities
0.3 mVhr
0.4 nrVhr
l.OmVhr
1.2 mVhr
1.9mVhr
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1
ป2
3
4
5
6
7
8
9
10
11
12
13
14
15
Table 7-14. Summary of Children's Inhalation Rates
For Short-Term Exposure Studies
Arithmetic Mean (nrVhr)
Activity Level
Rest Sedentary Light
Moderate
High
Reference
0.4
0.2
0.4
0.3
0.8
0.5
1.8
0.8
0.9
1.0
2.0
1.0
Adams, 1993 (Lab protocols)
Adams, 1993 {Field protocols)
2.5 Layton, 1993 (Short-term data)
2.2 Spier et al, 1992 (10-12 yrs)
Jl LinnetaL, 1992 (10-12 yrs)
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I APPENDIX 7A
2
3
4 VENTILATION DATA
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I
2
4
5
6
9
10
11
12
3
'14
15
TABLE 7A-1. Mean Minute Ventilation (Ve, L/min) by Group
And Activity for Laboratory Protocols
Activity
Lying
Sitting
Standing
Walking
Running
1 .5 mph
1.875mph
2.0 mph
2.25 mph
2.5 mph
3.0 mph
3.3 mph
4.0 mph
3.5 mph
4.0 mph
4.5 mph
5.0 mph
6.0 mph
Young Children3
6.19
6.48
6.76
10.25
10.53
DNP
11.68
DNP
DNP
DNP
DNP
DNP
DNP
DNP
DNP
DNP
Children
7.51
7.28
8.49
DNP
DNP
14.13
DNP
15.58
17.79
DNP
DNP
26.77
31.35
37.22
DNP
DNP
'Young Chiidren, male and female 3-5.9 yr olds; Children, male and female 6-12.9 yr olds; Adult Females,
adolescent, young to middle-aged, and older adult females; Adult Mates, adolescent, young to middle-aged,
and older adult males; DNP, group did not perform this protocol or N was too smali for appropriate mean
comparisons
Source: Adams (1993).
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1
2
3
4
5
6
7
8
9
10
II
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
TABLE 7A-2. Mean Minute Ventilation (Ve, L/min) by Group
^___ and Activity for Field Protocols
Activity
Young Children3
Children
Play
Car Driving
Car Riding
Yardwork
Housework
Car Maintenance
Mowing
Woodworking
11.31
DNP
DNP
DNP
DNP
DNP
DNP
DNP
17.89
DNP
DNP
DNP
DNP
DNP
DNP
DNP
'Young Children, male and female 3-5.9 yr olds; Children, male and female 6-12.9 yr olds; Adult Females,
adolescent, young to middle-aged, and older adult females; Adult Males, adolescent, young to middle-aged,
and older adult males; DNP, group did not perform this protocol orN was too small for appropriate mean
comparisons;
Source: Adams (J 993).
TABLE 7A-3. Statistics of the Age/gender Cohorts Used
To Develop Regression Equations for Predicting
Basal Metabolic Rates (BMR)
Gender/Age
(y)
Males
Under 3
3 to < 10
10 to < 18
Females
Under 3
3 to < 10
10 to < 18
BMR
MJd"1
1.51
4.14
5.86
L54
3.85
5.04
ฑSD
0.918
0.498
1.171
0.915
0.493
0.780
cva
0.61
0.12
0.20
0.59
0.13
0.15
Body
Weight
(kg)
6.6
21 -
42
6.9
21
38
Nb
162
338
734
137
413
575
BMR Equation0
0.249 bw- 0.1 27
0.095bw-f-2.110
0.074 bw + 2.754
0.244 bw- O.I 30
0.085 bw -r 2.033
0.056 bw + 2.898
rd
.0.95
0.83
0.93
0.96
0.81
0.8
'Coefficient of variation (SD/mean)
bN = number of subjects
cBody weight (bw) in kg
^coefficient of correlation
Source: Layton (1993).
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1 8. DERMAL ROUTE
2
3 8.1 INTRODUCTION
4 Children may be more highly exposed to environmental toxicants through dermal routes
5 than adults. For instance, children often play and crawl on contaminated surfaces and are more
6 likely to wear less clothing than adults. These factors result in higher dermal contact with
7 contaminated media. In addition, children have a higher surface area relative to body weight. In
8 fact, the surface-area-to-body weight ratio for newborn infants is more then two times greater
9 then that for adults (Cohen-Hubal et al., 1999).
10 Dermai exposure can occur during a variety of activities in different environmental media
11 and microenvironments (U.S. EPA, 1992a; 1992b). These include:
12 Water (e.g., bathing, washing, swimming);
13 * Soil (e.g., outdoor recreation, gardening, construction);
14 Sediment (e.g., wading, fishing);
15 Liquids (e.g., use of commercial products);
Vapors/fumes (e.g., use of commercial products); and
17 Indoors (e.g., carpets, floors, countertops).
18
19 The major factors that must be considered when estimating dermal exposure are: the
20 chemical concentration in contact with the skin, the extent of skin surface area exposed, the
21 duration of exposure, the absorption of the chemical through the skin, the internal dose, and the
22 amount of chemical that can be delivered to a target organ (i.e., biologically effective dose) (see
23 Figure 8-1). A detailed discussion of these factors can be found in Guidelines for Exposure
24 Assessment (U.S. EPA, 1992a). This chapter focuses on measurements of body surface areas
25 and dermal adherence of soil to the skin. Dermal Exposure Assessment: Principles and
26 Applications (U.S. EPA, 1992b), provides detailed information concerning dermal exposure
27 assessment using a stepwise guide in the exposure assessment process.
28
29
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Exposure
Chemical
Potential
Dose
Applied
Dose
Biologically
Effective
Dose
Internal
Dose
Metabolism
Effect
Skin
Uptake
Figure 8-1. Schematic of Dose and Exposure: Dermal Rome.
Source: U.S. Environmental Protection Agency (I992a).
1 8.2 SURFACE AREA
2 8.2.1 Background
3 The total surface area of skin exposed to a contaminant must be determined using
4 measurement or estimation techniques before conducting a dermal exposure assessment.
5 Depending on the exposure scenario, estimation of the surface area for the total body or a
6 specific body part can be used to calculate the contact rate for the pollutant. This section presents
7 estimates for total body surface area and for body parts and presents information on the
8 application of body surface area data.
9
10 8.2.2 Measurement Techniques
11 Coating, triangulation, and surface integration are direct measurement techniques that
12 have been used to measure total body surface area and the surface area of specific body parts.
13 Consideration has been given for differences due to age, gender, and race. The results of the
14 various techniques have been summarized in Development of Statistical Distributions or Ranges
15 of Standard Factors Used in Exposure Assessments (U.S. EPA, 1985). The coating method
16 consists of coating either the whole body or specific body regions with a substance of known or
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1 measured area. Triangulation consists of marking the area of the body into geometric figures,
2 then calculating the figure areas from their linear dimensions. Surface integration is performed
3 by using a planimeter and adding the areas.
4 The triangulation measurement technique developed by Boyd (1935) has been found to be
5 highly reliable. It estimates the surface area of the body using geometric approximations that
6 assume parts of the body resemble geometric solids (Boyd, 1935). More recently, Popendorf and
7 Leffingwell (1976), and Haycock et al. (1978) have developed similar geometric methods that
8 assume body parts correspond to geometric solids, such as the sphere and cylinder. A linear
9 method proposed by DuBois and DuBois (1916) is based on the principle that the surface areas of
10 the parts of the body are proportional, rather than equal to the surface area of the solids they
11 resemble.
12 In addition to direct measurement techniques, several formulae have been proposed to
13 estimate body surface area from measurements of other major body dimensions (i.e., height and
14 weight) (U.S; EPA, 1985). Generally, the formulae are based on the principles that body density
15 and shape are roughly the same and that the relationship of surface area to any dimension may be
6 represented by the curve of central tendency of their plotted values or by the algebraic expression
7 for the curve. A discussion and comparison of formulae to determine total body surface area are
18 presented in Appendix 8A.
19
20 8.2.3 Body Surface Area Studies
21 U.S. EPA (1985) - Development of Statistical Distributions or Ranges of Standard
22 Factors Used in Exposure Assessments - U.S. EPA (1985) analyzed the direct surface area
23 measurement data of Gehan and George (1970) using the Statistical Processing System (SPS)
24 software package of Buhyoff et al. (1982). Gehan and George (1970) selected 401 measurements
25 made by Boyd (1935) that were complete for surface area, height, weight, and age for their
26 analysis. Boyd (1935) had reported surface area estimates for 1,114 individuals using coating,
27 triangulation, or surface integration methods (U.S. EPA, 1985).
28 U.S. EPA (1985) used SPS to generate equations to calculate surface area as a function of
29 height and weight. These equations were then used to calculate body surface area distributions of
30 the U.S. population using the height and weight data obtained from the National Health and
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1 Nutrition Examination Survey (NHANES) n and the computer program QNTLS of Rochon and
2 Kalsbeek(1983). .
3 The equation proposed by Gehan and George (1970) was determined by U.S. EPA (1985)
4 to be the best choice for estimating total body surface area. However, the paper by Gehan and
5 George (1970) gave insufficient information to estimate the standard error about the regression.
6 Therefore, U.S. EPA (1985) used the 401 direct measurements of children and adults and
7 reanalyzed the data using the formula of Dubois and Dubois (1916) and SPS to obtain the
8 standard error. (U.S. EPA, 1985).
9 Regression equations were developed specific body parts using the Dubois and Dubois
10 (1916) formula and using the surface area of various body pars provided by Boyd (1935) and Van
11 Graan (1969) in.conjunction with SPS. Equations to estimate the body part surface area of
12 children were not developed because of insufficient data.
13 Percentile estimates for total surface area of male and female children presented in
14 Tables 8-1 and 8-2 were calculated using the total surface area regression equation, NHANES II
15 height and weight data, and using QNTLS. Estimates are not included for children younger than
16 2 years old because NHANES height data are not available for this age group. For children, the
17 error associated with height and weight cannot be assumed to be zero because of their relatively
18 small sizes. Therefore, the standard errors of the percentile estimates cannot be estimated, since
19 it cannot be assumed that the errors associated with the exogenous variables (height and weight)
20 are independent of that associated with the model; there are insufficient data to determine the
21 relationship between these errors.
22 Measurements of the surface area of children's body parts are summarized as a percentage
23 of total surface area in Table 8-3. Because of the small sample size, the data cannot be assumed
24 to represent-the average percentage of surface area by body part for all children. Note that the
25 percent of total body surface area contributed by the head decreases from childhood to adult,
26 while the percent contributed by the leg increases.
27 Phillips et al. (1993) - Distributions of Total Skin Surface Area to Body Weight Ratios -
28 Phillips et al. (1993) observed a strong correlation (0.986) between body surface area and body
29 weight and studied the effect of using these factors as independent variables in the LADD
30 equation. Phillips etal. (1993) concluded that, because of the correlation between these two
31 variables, the use of body surface area to body weight (SA/BW) ratios in human exposure
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1 assessments is more appropriate than treating these factors as independent variables. Direct
2 measurement (coating, triangulation, and surface integration) data from the scientific literature
3 were used to calculate body surface area to body weight (S A/BW) ratios for two age groups of
4 children (infants aged 0 to 2 years and children aged 2.1 to 17.9 years). These ratios were
5 calculated by dividing body surface areas by corresponding body weights for the 401 individuals
6 analyzed by Gehan and George (1970) and summarized by U.S. EPA (1985). Distributions of
7 SA/BW ratios were developed and summary statistics were calculated for the two age groups and
8 the combined data set. Summary statistics for the two children's age groups are presented in -
9 Table 8-4. The shapes of these SA/BW distributions were determined using D'Agostino's test.
10 The results indicate that the SA/BW ratios for infants are lognormally distributed. SA/BW ratios
11 for children were neither normally nor lognormaliy distributed. According to Phillips et al.
12 (1993), SA/BW ratios should be used to calculate LADDs by replacing the body surface area
13 factor in the numerator of the LADD equation with the SA/BW ratio and eliminating the body
14 weight factor in the denominator of the LADD equation.
15 The effect of gender arid age on SA/BW distribution was also analyzed by classifying the
401 observations by gender and age. Statistical analyses indicated no significant differences
between SA/BW ratios for males and females. SA/BW ratios were found to decrease with
18 increasing age.
19 Wong et al. (2000) - Adult Proxy Responses to a Survey of Children's Dermal Soil
20 Contact Activities - Wong et al. (2000) conducted telephone surveys to gather information on
21 children's activity patterns as related to dermal contact with soil during outdoor play on bare dirt
22 , or mixed grass and dirt surfaces. This study, the second Soil Contact Survey (SCS-II), was a
23 follow-up to the initial Soil Contact Survey (SCS-I), conducted in 1996, that primarily focused
24 on assessing adult behavior related to dermal contact with soil and dust (Garlock et al., 1999).
25 As part of SCS-I, information was gathered on the behavior of children under the age of 18 years,
26 however, the questions were limited to clothing choices and the length of time after soil contact
27 to hand washing. Results obtained for children from SCS-I were not reported in Garlock et al.
28 (1999), but some of the collected information is summarized in Wong et al (2000). Questions
29 were posed for SCS-II to further define children's outdoor activities and hand washing and
30 bathing frequency. For both soil contact surveys households were randomly phoned in order to
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1 obtain nationally representative results. The adult respondents were questioned as surrogates for
2 one randomly chosen child under the age of 18 residing within the household.
3 For SCS-I, the population size of children sampled was 211. Older children (those
4 between the ages of 5 and 17) were questioned regarding participation in "gardening and
5 yardwork," "outdoor sports," and "outdoor play activities." For children less than 5 years old,
6 "outdoor play activities" occurring on a playground or yard with "bare dirt or mixed grass and
7 dirt" surfaces were noted. The clothing worn during these play activities during warm weather
8 months (April though October) also was questioned. For both groups of children, information
9 was gathered concerning hand washing, bathing, and clothes changing habits after soil contact
10 activities, but these results are not reported in Wong et al. (2000).
11 Results of SCS-I indicate that most children wore short pants, a dress or skin, short
12 sleeve shirts, no socks, and leather or canvas shoes during the outdoor play activities of interest.
13 Using data from Anderson et al. (1985) percentages of total body surface area associated with
14 specific body parts were estimated (Table 8-5). Then exposed skin surface areas for children
15 under age 5 were estimated per clothing item as well as for all clothing items worn together
16 during warm weather outdoor play (Table 8-6). Faces and hands were assumed to be exposed
17 under all conditions with the face having a constant surface area fraction of 5 percent and the
18 hands 6 percent.
19 In the SCS-II, of 680 total adult respondents with a child in their household, 500 (73.5%)
20 reported that their child played outdoors on bare dirt or mixed grass and dirt surfaces (identified
21 as "players"). Those children that reportedly did not play outdoors ("non-players") were
22 typically very young (< 1 year) or relatively older (> 14 years). Of the 500 children that played
23 outdoors, 497 played outdoors in warm weather months (April through October) and 390 were
24 reported to play outdoors during cold weather months (November through March). These results
25 are presented in Table 8-7. The frequency (days/week), duration (hours/day), and total hours per
26 week spent playing outdoors was determined for those children identified as "players"
27 (Table 8-8). The responses indicated that during the warmer months children spend a relatively
28 high percentage of time outdoor and a lesser amount of time in cold weather. The median play
29 frequency reported was 7 days/week in warm weather and 3 days/week in cold weather. Median
30 play duration was 3 hours/day in warm weather and 1 hour/day during cold weather months.
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1 Adult respondents were then questioned as to how many times per day their child washed
12 his/her hands and how many times the child bathed or showered per week during both warm and
3 cold weather months. This information provided an estimate of the time between skin contact
4 with soil and removal of soil by washing (i.e., exposure time). Hand washing and bathing
5 frequencies for child players are reported in Table 8-9. Based on these results, hand washing
6 occurred a median of 4 times per day during both warm and cold weather months. The median
7 frequency for baths and showers was estimated to be 7 times per week for both warm and cold
8 weather.
9 Based on reported household incomes, the respondents sampled in SCS-II tended to have
10 higher incomes than that of the general population. This may be explained by the fact that phone
11 surveys cannot sample those households without telephones. Additional uncertainty or error in
12 the study results may be presented by the use of surrogate respondents. Adult respondents were
13 questioned regarding child activities that may have occurred in prior seasons, introducing the
14 chance of recall error. In some instances, a respondent did not know the answer to a question or
15 refused to answer. In Tables 8-10 and 8-11 iformation extracted from the National Human
16 Activity Pattern Survey (NHAPS) (U.S. EPA, 1996). Table 8-10 compares mean play duration -
11 data from SCS-II to similar activities identified in NHAPS. The number of times per day a child
18 washed his or her hands was presented in both SCS-II and NHAPS follow-up survey B and are
19 shown in Table 8-11. Corresponding information for bathing frequency data collected from
20 SCS-II was not collected in NHAPS. As indicated in Tables 8-10 and 8-11, where comparison is
21 possible, NHAPS and SCS-II results showed similarities in observed behaviors.
22
23 8.2.4 Application of Body Surface Area Data
24 For swimming and bathing scenarios, past exposure assessments have assumed that
25 75 percent to 100 percent of the skin surface is exposed (U.S. EPA, 1992b). Central and upper-
26 percentile values for children should be derived from Table 8-1 or 8-2.
27 Unlike exposure to liquids, clothing may or may not be effective in limiting the extent of
28 exposure to soil. The children clothing scenarios are presented below.
29 Central tendency mid range: Child wears long sleeve shirt, pants, and shoes. The
.30 exposed skin surface is limited to the head and hands. Table 8-3 can be used to determine
the skin surface area depending on the age group of interest.
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I
2
**
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Upper percentile: Child wears a short sleeve shirt, shorts, and shoes. The exposed skin
surface is limited to the head, hands, forearms, and lower legs. Table 8-3 can be used to
determine the skin surface area depending on the age group of interest.
The clothing scenarios presented above, suggest that roughly 10 percent to 25 percent of the skin
area may be exposed to soil. Since some studies have suggested that exposure can occur under
clothing, the upper end of this range was selected in Dermal Exposure Assessment: Principles
and Applications (U.S. EPA, 1992b) for deriving defaults. Default values for children can be
derived by multiplying the 50th and 95th percentiles of the total surface area by 0.25 for the ages
of interest.
When addressing soil contact exposures, assessors may want to refine estimates of
surface area exposed on the basis of seasonal conditions. For example, in moderate climates, it
may be reasonable to assume that 5 percent of the skin is exposed during the winter, 10 percent
during the spring and fall, and 25 percent during the summer.
The previous discussion, has presented information about the area of skin exposed to soil.
These estimates of exposed skin area should be useful to assessors using the traditional approach
of multiplying the soil adherence factor by exposed skin area to estimate the total amount of soil
on skin. The next section presents soil adherence data specific to activity and body part and is
designed to be combined with the total surface area of that body part. No reduction of body part
area is made for clothing coverage using this approach! Thus, assessors who adopt this approach,
should not use the defaults presented above for soil exposed skin area. Rather, they should use
Table 8-3 to estimate surface areas of specific body parts.
8.3 SOIL ADHERENCE TO SKIN
8.3.1 Background
Soil adherence to the surface of the skin is a required parameter to calculate dermal dose
when the exposure scenario involves dermal contact with a chemical in soil. A number of
studies have attempted to determine the magnitude of dermal soil adherence. These studies are
described in detail in U.S. EPA (1992b). This section summarizes recent studies that estimate
soil adherence to skin for use as exposure factors.
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1 8.3.2 Soil Adherence to Skin Studies
2 Kissel et al. (I996a) - Factors Affecting Soil Adherence to Skin in Hand-Press Trials:
3 Investigation of Soil Contact and Skin Coverage - Kissel et al. (1996a) conducted soil adherence
4 experiments using five soil types (descriptor) obtained locally in the Seattle, Washington, area:
5 sand (211), loamy sand (CP), loamy sand (85), sandy loam (228), and silt loam (72). All soils
6 were analyzed by hydrometer (settling velocity) to determine composition. Clay contents ranged
7 from 0.5 to 7.0 percent. Organic carbon content, determined by combustion, ranged from 0.7 to
8 4.6 percent. Soils were dry sieved to obtain particle size ranges of <150, 150-250, and >250 #m.
9 For each soil type, the amount of soil adhering to an adult female hand, using both sieved and
10 unsieved soils, was determined by measuring the difference in soil sample weight before and
11 after the hand was pressed into a pan containing the test soil. Loadings were estimated by
12 dividing the recovered soil mass by total hand area, although loading occurred primarily on only
13 one side of the hand. Results showed that generally, soil adherence to hands could be directly
14 correlated with moisture content, inversely correlated with particle size, and independent of clay
15 content or organic carbon content.
6 Kissel et al (1996b) - Field Measurement of Dermal Soil Loading Attributable to Various
17 Activities: Implications for Exposure Assessment - Further experiments were conducted by
18 Kissel et al. (1996b) to estimate soil adherence associated with various indoor and outdoor
19 activities: greenhouse gardening, tae kwon do karate, soccer, rugby, reed gathering, irrigation
20 installation, truck farming, and playing in mud. Several of the activities studied by Kissel
21 (1996b) involved children, as shown in Table 8-12. A summary of field studies by activity,
22 gender, age, field conditions, and clothing worn is presented in Table 8-12. Subjects' body
23 surfaces (forearms, hands, lower legs in all cases, faces, and/or feet; pairs in some cases) were
24 washed before and after monitored activities. Paired samples were pooled into single ones.
25 Mass recovered was converted to loading using allometric models of surface area. These data are
26 presented in Table 8-13. Results presented are based on direct measurement of soil loading on
27 the surfaces of skin before and after activities that may be expected to have soil contact (Kissel et
28 al., 1996b). The results indicate that the rate of soil adherence to the hands is higher than for
29 other parts of the body.
30
June 2000 8-9 DRAFT-DO NOT QUOTE OR CITE
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1 Holmes, Jr., K.K., J.H. Shirai, K. Y. Richter, andJ.C. Kissel (1999) - Field Measurement
2 of Dermal Soil Loadings in Occupational and Recreational Activities - Holmes et al. (1999)
3 collected pre- and post-activity soil loadings on various body parts of individuals within groups
4 engaged in various occupational and recreational activities. These groups included children at a
5 daycare center and playing indoors in a residential setting. This study was conducted as a follow
6 up to previous field sampling of soil adherence on individuals participating in various activities
7 (Kissel et al., 1996). For this round of sampling, soil loading data were collected utilizing the
8 same methods used and described in Kissel et al. (1996). Information regarding the groups of
9 children studied and their observed activities are presented in Table 8-14.
10 The daycare children studied were all at one location and measurements were taken on
11 three different days. The children freely played both indoors in the house and outdoors in the
12 backyard. The backyard was described as having a grass lawn, shed, sand box, and wood chip
13 box. In this setting, the children engaged in typical activities including: playing with toys and
14 each other, wrestling, sleeping, and eating. The number of children within each day's group and
15 the clothing worn is described in Table 8-15.
16 The five children measured on the first day were washed first thing in the morning to
17 establish a preactivity level. They were next washed at noon to determine the postactivity soil
18 loading for the morning (Daycare kids No. 1 a). The same children were washed once again at
19 the close of the day for measurement of soil adherence from the afternoon play activities
20 (Daycare kids No. Ib).
21 For the second observation day (Daycare kids No. 2), postactivity data were collected for
22 five children. All the activities on this day occurred indoors. For the third daycare group
23 (Daycare kids No. 3), four children.were studied.
24 On two separate days, children playing indoors in a home environment were monitored.
25 The first group (Indoor kids No. 1) had four children while the second group (Indoor kids No. 2)
26 had six children. The play area was described by Holmes et al. (1999) as being primarily
27 carpeted. The clothing worn by the children within each day's group is described in Table 8-15.
28 The geometric means and standard deviations of the postactivity soil adherence for each
29 group of children and for each body part are summarized in Table 8-16. According to Holmes et
30 ' al. (1999), variations in the soil loading data from the daycare participants reflect differences in
31 the weather and access to the outdoors.
June 2000
8-10
DRAFT-DO NOT QUOTE OR CITE
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1 An advantage of this study is that it provides a supplement to soil loading data collected
\2 in a previous round of studies (Kissel et al, 1996b). Also, the data support the. assumption that
3 hand loading can be used as a conservative estimate of soil loading on other body surfaces for the
4 same activity. The activities studied represent normal child play both indoors and outdoors, as
5 well as for different combinations of clothing. The small number of participants (n) is a
6 disadvantage of this study. Also, the children studied and the activity setting may not be
7 representative of the U.S. population.
8 Kissel et al. (1998) - Investigation of Derma! Contact with Soil in Controlled Trials In
9 this study, Kissei et al.(1998) measured dermal exposure to soil from staged activities conducted
10 in a greenhouse. A fluorescent marker was mixed in soil so that soil contact for a particular skin
11 surface area could be identified. As described in Kissel et al.( 1998), the subjects, which included
12 a group of children, were video imaged under a long-wave ultraviolet (UV) light before and after
13 soil contact. In this manner, soil contact on hands, forearms, lower legs, and faces was assessed
14 by presence of fluorescence. In addition to fluorometric data, gravimetric measurements for
15 preactivity and postactivity were obtained from the different body parts examined.
gmi6 The studied group of children played for 20 minutes in a soil bed of varying moisture
17 content representing wet and dry soils. For wet soils, both combinations of long sleeves and long
18 pants and short sleeves and short pants were tested. Children only wore short sleeves and short
19 pants during play in the dry soil. Clothing was laundered after each trail. Thus, a total of three
20 trials with children were conducted. The parameters describing each of these trials are
21 summarized in Table 8-17.
22 Before each trial, each child was washed in order to obtain a preactivity or background
23 gravimetric measurement. Preactivity data are shown in Table 8-18. Body part surface areas
24 were calculated using Anderson et al. (1985) for the range of heights and weights of the study
25 participants.
26 For wet soil, postactivity fluorescence results indicated that the hand had a much higher
27 fractional coverage than other body surfaces (see Figure 8-2). No fluorescence was detected on
/
28 the forearms or lower legs of children dressed in long sleeves and pants.
29 As shown in Figure 8-3, postactivity gravimetric measurements showed higher soil
30 loading on hands and much lower amounts on other body surfaces, as was observed with
fluorescence data. According to Kissel etal. (1998), the relatively low loadings observed on
J June 2000 8-11 DRAFT-DO NOT QUOTE OR CITE
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1
2
3
4
5
6
7
8
9
10
11.
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
non-hand body parts may be a result of the limited area of contact rather than lower localized
loadings. A geometric mean dermal loading of 0.7 mg/cm2 was found on children's hands
following play in wet soil. Mean loadings were lower on hands in the dry soil tria! and on lower
legs, forearms, and faces in both the wet and dry soil trials. Higher loadings were observed for
all body surfaces with the higher moisture content soils.
This report is valuable in showing soil loadings from soils of different moisture content
and providing evidence that dermal exposure to soil is not uniform for various body surfaces.
There is also some evidence from this study demonstrating the protective effect of clothing.
Disadvantages of the study include a small number of study participants and a short activity
duration. Also, no information is provided on the ages of the children involved in the study.
8.4 RECOMMENDATIONS
8.4.1 Body Surface Area
Body surface area estimates are based on direct measurements. Re-analysis of data
collected by Boyd (1935) by several investigators (Gehan and George, 1970; U.S. EPA, 1985;
Murray and Burmaster, 1992; Phillips et al., 1993) constitutes much of this literature. Methods
are highly reproducible and the results are widely accepted. The representativeness of these data
to the general population is somewhat limited since variability due to race or gender have not
been systematically addressed.
The recommendations for body surface area for children are summarized in Table 8-19.
These recommendations are based on U.S. EPA (1985) and Phillips et al. (1993). Table 8-20
presents the confidence ratings for various aspects of the recommendations for body surface area.
The U.S. EPA (1985) study is based on generally accepted measurements that enjoy widespread
usage, summarizes and compares previous reports in the literature, provides statistical
distributions for adults, and provides data for total body surface area and body parts by gender for
children. The results are based on selected measurements from the original data collected by
Boyd (1935). Phillips et al. (1993) analyses are based on direct measurement data that provide
distributions of body surface area to calculate LADD. The results are consistent with previous
efforts to estimate body surface area. Analyses are also based on measurements selected from the
original measurements made by Boyd (1935) and data were not analyzed for specific body parts.
June 2000
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DRAFT-DO NOT QUOTE OR CITE
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1 8.4.2 Soil Adherence to Skin
12 Recommendations for the rate of soil adherence to the skin are based "on data collected by
3 Kissel et al. (1996a; 1996b) for specific activities. The experimental design and measurement
4 methods used by Kissel et al. (1996a; 1996b) are straightforward and reproducible, but it should
5 be noted that the controlled experiments and field studies are based on a limited number of
6 measurements and specific situations were selected to assess soil adherence to skin.
7 Consequently, variation due to individuals, protective clothing, temporal, or seasonal factors
8 remain to be studied in more detail. Therefore, caution is required in interpretation and
9 application of these results for exposure assessments.
} 0 In consideration, of these general observations and the recent data from Kissel et al.
11 (1996a, 1996b), changes are needed from past EPA recommendations which used one adherence
12 value to represent all soils, body parts, and activities. One approach would be to select the
13 activity from Table 8-12 which best represents the exposure scenario of concern and use the
14 corresponding adherence value from Table 8-13. Although this approach represents an
15 improvement, it still has shortcomings. For example, it is difficult to decide which activity in
16 Table 8-13 is most representative of a typical residential setting involving a variety of activities.
17 It may be useful to combine these activities into general classes of low, moderate, and high
18 contact. In the future, it may be possible to combine activity-specific soil adherence estimates
19 with survey-specific soil adherence estimates with survey-derived data on activity frequency and
20 duration to develop overall average soil contact rates. EPA is sponsoring research to develop
21 such an approach. As this information becomes available, updated recommendations will be
22 issued.
23 Table 8-13 provides the best estimates available on activity-specific adherence values, but
24 are based on limited data. Therefore, they have a high degree of uncertainty such that
25 considerable judgment must be used when selecting them for an assessment. The confidence
26 ratings for various aspects of this recommendation are summarized in Table 8-21. Insufficient
27 data are available to develop a distribution or a probability function for soil loadings.
28 Past EPA guidance has recommended assuming that soil exposure occurs primarily to
29 exposed body surfaces and used typical clothing scenarios to derive estimates of exposed skin
30 . area. The approach recommended above for estimating soil adherence addresses this issue in a
rl different manner. This change was motivated by two developments. First, increased acceptance
June 2000 8-13 DRAFT-DO NOT QUOTE OR CITE
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1 that soil and dust particles can get under clothing and be deposited on skin. Second, recent
2 studies of soil adherence have measured soil on entire body parts (whether or not they were
3 covered by clothing) and averaged the amount of soil adhering to skin over the area of entire
4 body part. The soil adherence levels resulting from these new studies must be combined with the
5 surface area of the entire body part (not merely unclothed surface area) to estimate the amount of
6 contaminant on skin. An important caveat, however, is that this approach assumes that clothing
7 in the exposure scenario of interest matches the clothing in the studies used to derive these
8 adherence levels such that the same degree of protection provided by clothing can be assumed in
9 both cases. If clothing differs significantly between the studies reported here and the exposure
10 scenarios under investigation, considerable judgment is needed to adjust either the adherence
11 level or surface area assumption.
12 The dermal adherence value represents the amount of soil on the skin at the time of
13 measurement. Assuming that the amount measured on the skin represents its accumulation
14 between washings and that people wash at least once per day, these adherence values can be
15 interpreted as daily contact rates (U.S. EPA, 1992b). However, this is not recommended because
16 the residence time of soils on skin has not been studied. Instead, it is recommended that these
17 adherence values be interpreted on an event basis (U.S. EPA, 1992b).
June 2000
8-14
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8.5 REFERENCES FOR CHAPTER 8
3 Anderson E., Browne N., Duletsky S., Ramig J. and Warn T. (1985) Development of Statistical Distributions or
4 Ranges of Standard Factors Used in Exposure Assessments. U. S. EPA Office of Health and
5 Environmental Assessment, Washington, D.C. NTIS PB85-242667.
6
7 Boyd, E. (1935) The growth of the surface area of the human body. Minneapolis, Minnesota: University of
8 Minnesota Press.
9
10 Buhyoff, G.J.; Rauscher, H.M.; Hull, R.B.; Killeen, K.; Kirk, R.C. (1982) User's Manual for Statistical Processing
11 System (version 3C.1). Southeast Technical Associates, Inc.
12 .
13 Cohen-Hubal, E.A.; Sheldon, L.S.; Burke, J.M.; McLundy, T.R.; Berry, M.R.; Rigas, M.L.; Zartarian, V.G.;
14 Freeman, N.C.G. (1999) Children's exposure assessment: A review of factors influencing children's
15 exposure, and the data available to characterize and assess that exposure. Research Triangle Park, NC:
16 U.S. Environmental Protection Agency, National Exposure Research Laboratory.
17
18 Dubois, D.; Dubois. E.F. (1916) A formula to estimate the approximate surface area if height and weight be
19 known. Arch, of Intern. Med. 17:863-871.
20
21 Gehan, E.; George, G.L. (1970) Estimation of human .body surface area from height and weight. Cancer
22 Chemother. Rep. 54(4):225-235.
23
24 Garlock T.J.. Shirai, J.H. and Kissel, J.C. (1999) Adult responses to a survey of soil contact related behaviors. J.
25 Exposure Anal. Environ. Epid. 1999: 9: 134-142.
26
Geigy Scientific Tables (1981) Nomograms for determination of body surface area from height and mass. Lentner,
C. (ed.). CIBA-Geigy Corporation, West Caldwell, NJ. pp. 226-227.
29
30 Georae, S.L.; Gehan, E.A.; Haycock, G.B.; Schwartz, GJ. (1979) Letters to the editor. J. Ped. 94(2):342.
31
32 Haycock, G.B.; Schwartz, G.J.; Wisotsky, D.H. (1978) Geometric method for measuring body surface area:
33 A height-weight formula validated in infants, children, and adults. J. Ped. 93(l):62-66.
34
35 Holmes. K.K.; Kissel. J.C.; Richter, K.Y. (1996) Investigation of the influence of oil on soil adherence to skin. J.
36 Soil. Contam. 5(4):301-308.
37
38 Holmes, Jr.. K.K., J.H. Shirai, K.Y. Richter, and J. C. Kissel (1999) Field Measurement of Dermal Loadings in
39 Occupational and Recreational Activities, Environmental Research, Section A. 80, 148-157.
40
41 Kissel, J.; Richter, K.; Duff, R.; Fenske, R. (1996a) Factors Affecting Soil Adherence to Skin in Hand-Press Trials.
42 Bull. Environ. Contamin. Toxicol. 56:722-728.
43
44 Kissel. J.: Richter. K.: Fenske. R. (I996b) Field measurements of dermal soil loading attributable to various
45 activities: implications for exposure assessment- Risk Anal. 16(1): 116-125.
46
47 Kissel, J.C.. Shirai. J. H., Richter, K.Y., and R.A. Fenske (1998) Investigation of Dermal Contact with Soil in
48 Controlled Trials. Journal of Soil Contamination. 7(6): 737-752.
49
50 Murray, D.M.; Burmaster. D.E. (1992) Estimated distributions for total surface area of men and women in the
51 United States. J. Expos. Anal. Environ. Epidemiol. 3(4):451-462.
9
June 2000 8-15 DRAFT-DO NOT QUOTE OR CITE
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1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
Phillips, L.J.; Fares, R.J.; Schweer, L.G. (1993) Distributions of total skin surface area to body weight ratios for
use in dermal exposure assessments. J. Expos. Anal. Environ. Epidemiol. 3(3):331-338.
Po'pendorf, W.J.; Leffingwell, J.T. (1976) Regujating OP pesticide residues for farmworker protection.
In: Residue Review 82. New York, NY: Springer-Veriag New York, Inc., 1982. pp. 125-201.
Rochon, J.; Kalsbeek, W.D. (1983) Variance estimation from multi-stage sample survey data: the jackknife
repeated replicate approach. Presented at 1983 SAS Users Group Conference, New Orleans, Louisiania,
January 1983.
Sendroy, J.; Cecchini, L.P. (1954) Determination of human body surface area from height and weight. J. Appl.
Physiol. 7(1):3-12.
U.S. EPA. (1985) Development of statistical distributions or ranges of standard factors used in exposure
assessments. Washington, DC: Office of Research and Development, Office of Health and Environmental
Assessment. EPA 600/8-85-010. Available from: NTIS, Springfield, VA. PB85-242667.
U.S. EPA. (1992a) Guidelines for exposure assessment. Federal Register. FR 57:104:22888-22938. May 29,
1992.
U.S. EPA. (1992b) Dermal exposure assessment: principles and applications. Washington, DC: Office of
Research and Development, Office of Health and Environmental Assessment/OHEA. U.S.
EPA/600/8-9-91.
U. S. Environmental Protection Agency (U.S. EPA) (1996) Analysis of the National Human Activity Pattern Survey
(NHAPS) Respondents from a Standpoint of Exposure assessment. Office of Research and Development,
Washington, D.C., EPA/600/R-96/074.
Van Graan, C.H. (1969) The determination of body surface area. Supplement to the South African J. of Lab. and
Clin. Med. 8-2-69.
Wong E. Y., Shirai, J.H, Garlock, T. J., and Kissel, J.C. (2000) Adult Proxy Responses to a Survey of Children's
Dermal Soil Contact Activities, Submitted for publication.
June 2000
8-16
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Table 8-1. Total Body Surface Area of Male
Children in Square Meters*
A.\
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
,7
8
30
31
32
33
34
35
;v "
(yr)
2<3
3<4
4<5
5<6
6<7
7<8
8<9
9<10
10< 11
1K12
12<13
13<14
14<15
15
-------
1
2
3
Table 8-2. Total Body Surface Area of Female
Children in Square Meters"
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
Age(yr)b
2<3
3<4
4<5
5<6
6<7
7<8
8<9
9
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Table 8-5. Clothing choices and assumed body surface areas exposed
1 3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
E4
25
26
27
28
29
30
31
Clothing response
Long pants
Short pants
Long sleeves
Short sleeves
No shirt (males)
Halter (females)
High socks
Low socks
No socks
Shoes
No shoes or sandals
Gloves
No gloves
Hat or no hat
Maximum exposure
a After Anderson
Area assumed exposed
Jower Vi of thigh and upper 'A of lower leg
forearms
3/4 trunk and arms
Yz trunk and arms
1/4 lower leg
bottom half lower leg
feet
hands
1/3 head for face
et. al(!985).
Table 8-6. Estimated skin surface exposed during warm
under age 5 (based on SCS-I
% of total body surface area"
M
0
13
0
6
38
n/a
0
3
6
0
7
0
6
5
75
F
0
13
0
6
n/a
30
0
3
6
0
7
0
6
5
67
weather outdoor play for children
data).
, Skin area exposed (% of total) based on expressed choice of
n
Mean
Median
S.D.
pants shirt sleeves socks
41 43 42
12.8 6.6 4.4
13.0 6.0 5.3
1.0 2.7 1.7
shoes hat* all
43 43
3.0 5.0
3.5 5.0
3.2 0.0
clothing
41
32.0
30.5
6.0
32
33
a Face was assumed to always be exposed.
June 2000
8-21
DRAFT-DO NOT QUOTE OR CITE
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Table 8-12. Summary of Field Studies
1 3 Event" Age
4 Activity Month (hrs) Nb M F (yrs) Conditions Clothing
5
6
7
8
9
10
indoor
Tae Kwon Do Feb.
Indoor Kids No. 1 Jan.
Indoor Kids No. 2 Feb.
Daycare Kids No. la Aug.
1 .5 761 8-42 Carpeted floor All in longsieeve-long pants
martial arts uniform, sleeves
rolled back, barefoot
2 43 1 6-13 Playing on carpeted floor 3 of 4 short pants, 2 of 4 short
sleeves, socks, no shoes
2 6 4 2 3-! 3 Playing on carpeted floor 5of 6 long pants, 5 of 6 long
sleeves, socks, no shoes
3:5' 6 5 1 1-6.5 Indoors: linoleum surface; 4 of 6 in long pants, 4 of 6
1-1
12
[4
15
16
17
18
19
20
21
9 2
23
24
25
Daycare Kids No. lb Aug. 4 6
Daycare Kids No.2c Sept. 8 . 5
Daycare Kids No. 3 Nov. 8 4
Outdoor
Soccer No. 1
Nov. 0.67 8
Gardeners No. 1 Aug. 4 8
outdoors: grass, bare earth, short sleeves, shoes
barked area
5 1 1-6.5 indoors: linoleum surface; 4 of 6 in long pants, 4 of 6
outdoors: grass, bare earth, short sleeves, no shoes
barked area
4 1 i-4 Indoors, low napped 4 of 5 long pants, 3of 5 long
carpeting, linoleum sleeves, all barefoot for part
surfaces of the day
3 1 1-45 Indoors: linoleum surface, All long pants, 3 of 4 long
outside: grass, bare earth, sleeves, socks and shoes
barked area
8 0 13-15 Half grass-half bare earth 6 of 8 long sleeves, 4 of 8
long pants, 3 of 4 short pants
and shin guards
1 7 16-35 Weeding, pruning,digging 6 of 8 long pants, 7 of 8 short
Archeologists
July 11.5 7
Kids-in-mud No. 1 Sept. 0.17 6
Kids-in-mud No. 2 Sept. 0.33 6
a trench
3 4 16-35 Digging withtrowel,
screening dirt, sorting
5 I 9-14 Lake shoreline
5 1 9-14 Lake shoreline
sleeves. 1 sleeveless, socks,
shoes, intermittent use of
gloves
6 of 7 short pants.a!I short
sleeves, 3 no shoes or socks,
2 sandals
All in short sleeve T-shirts,
shorts, barefoot
All in short sleeve T-shirts,
shorts barefoot
'Event duration
"Number of subject
'Activities were confined to the house
Sources: Kissel et al. (1996b); Holmes et al. (1996).
June 2000
8-25
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1
2
3
4
5-
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
Table
8-13. Geometric Mean And Geometric Standard Deviations of
Soil Adherence by Activity And Body Region
Activity
Indoor
Tae Kwon Do
Indoor Kids No. 1
Indoor Kids No. 2
Daycare Kids No. la
Daycare Kids No. Ib
Daycare Kids No. 2
Daycare Kids No. 3
Outdoor
Soccer No. 1
Gardeners No. 1
Archeoiogists
Kids-in-mud No. 1
Kids-in-mud No. 2
'Number of subjects.
Sources: Kissel et al.
*
N"
7
4
6
6
6
5
4
8
8
7
6
6
(1996b);
Hands
0.0063
1.9
0.0073
1.9
0.014
1.5
0.11
1.9
0.15
2.1
0.073
1.6
0.036
1.3
0.11
1.8
0.20
1.9
0.14
1.3
35
2.3
58
2.3
Holmes et al.
Post-activity
Arms
0.0019
4-1
0.0042
1.9
0.0041
2.0
0.026
1.9
0.031
1.8
0.023
1.4
0.012
1.2
0.011
2.0
0.050
2.1
0.041
1.9
II
6.1
11-
3.8
(1996).
Dermal Soil Loadings (mg/cm2)
Legs Faces
0.0020
2.0
0.0041
2.3
0.0031
1.5
0.030
1.7
0.023
1.2
0.01 1
1-4
0.014
3.0
0.031 0.012
3.8 1.5
. 0.072 0.058
1.6
0.028 0.050
4.1 1.8
36
2.0
9.5
2.3
Feet
0.0022
2.1
0.012
1.4
0.0091
1.7
0.079
2.4
0.13
1.4
0.044
1.3
0.0053
5.1
0.17
-
0.24
1.4
24
3.6
6.7
12.4
June 2000
8-26
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1
2
(3
4
5
6
7
8
9
10
11
Table 8- 14.
Activity
Daycare kids No. la
Daycare kids No. Ib
Daycare kids No. 2
Daycare kids No. 3
Indoor kids No. 1
Indoor kids No. 2
a Event duration.
b Number of subjects.
Summary of Groups Assayed in Round 2 of Field Measurements
Month
Aug.
Aug.
Sept.
Nov.
Jan.
Feb.
Event* (hrs)
3.5
4
8
8
2
2
n"
6
6
5
4
4
6
Males
5
5
4
3
3
4
Females
1
1
I
1
1
2
Ages
1-6.5
1-6.5
I - 4
1 -4.5
6-13
3 -13
June 2000
8-27
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1
2
3
4
5
6
7
8
9
10
U
12
13
14
15
16
17
Table 8- 15
. Attire for Individuals within Children
Pants
Activity
Daycare kids No. la
Daycare kids No. Ib
Daycare kids No. 2
Daycare kids No. 3b
Indoor kids No. I
Indoor kids No. 2
a Number of subjects.
ff
6
6
5
4
4
6
Long
4
4
4
4
1
5.
Short
2
2
1
0
3
1
Sleeves
Long Short
1 5
1 5
2 3
3 I
2 2
5 1
's Groups Studied
Socks Shoes
High
1
1
NA
0
0
0
Low
5 low leather or canvas
shoes - 6
5 barefoot - 3
low leather or canvas
shoes - 3
NA barefoot - 2
shoes/socks % day and
barefoot Vi day - 3
4 low shoes - 4
4 no shoes (socks only) -
6 no shoes (socks only) -
4
6
b All children wore jackets when engaged in outdoor activities.
NA - "Not Available": 3
socks worn.
children
wore socks
for '/= day
in the morning but no specific
information is provided on the type of
June 2000
8-28
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1
2
3
4
5
6
' 7
8
9
10
11
12
13
14
15
Table 8-16. Geometric Means (Geometric
Standard Deviations) of Round 2 Post-activity Loadings
Postactivity Dermal Soil Loadings (mg/crn2)
Activity
Daycare kids No. la
Daycare kids No. 1 b
Daycare kids No. 2
Daycare kids No. 3
Indoor kids No. 1
Indoor kids No. 2
n" Hands
4 0.11(1.9)
6 0.15(2.1)
6 0.073(1.6)
6 0.036(1.3)
5 0.0073(1.9)
4 0.014(1.5)
Forearms
0.026(1.9)
0.031 (1.8)
0.023(1.4)
0.012(1.2)
0.0042(1.9)
0.0041 (2.0)
Lower legs Faces6
0.030(1.7)
0.023(1.2)
0.011 (1.4)
0.014(3.0)
0.0041 (2.3)
0.0031 (1.5)
Feet
0.079 (2.4)
0.13(1.4)
0.044(1.3)
0.0053(5.1)
0.012(1.4)
0.0091 (1.7)
a Number of subjects (number of data points for specific non-hand body parts may deviate slightly).
b Children's feet rather than faces were washed in order to reduce the chance of a child's refusal to panicipate.
June 2000
8-29
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1
2
Table 8-17. Summary of Controlled Green House Trials - Children Playing
Activity Ages
Duration
(min)
Soil moisture Clothing3 n
Male
Female
5
6
7
8
Playing 8-12
20
17-18
16-18
3-4
L
S
S
4
9
5
3
5
I
4
2
a L, long sleeves and long pants; S, short sleeves and short pants.
June 2000
8-30
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1
2
3
4
5
Table 8-18. Preactivity Loadings Recovered from Greenhouse Trial Children Volunteers
Area
Body part surface area (cm2)
Geometric mean
(95% C.I.) (ng/cnr)
Hands
Forearms
Lower legs
Face
12
12
12
420-798
584-932
1,206-2,166
388-602
9.4
(5.4-15.8)
3.4
(2.3 - 5.2)
1.0
(0.7-1.5)
0.8
(0.5-1.5)
10
11
June 2000
8-31
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1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
Hands
Lower legs/short pants
Forearms/short sleeves
Faces -4
Adult
Child
"I * ' ^^^^^ I "*"^^
20 40 60
Percent Fluorescing
80
"i
100
Figure 8-2. Skin Coverage as Determined by Fluorescence vs. Body Part for Adults
Transplanting Plants and for Children Playing in Wet Soils
adult x
child, wet +
O
% H
JJ ;
^b
.5 0.3 J
"ง
S 3
=
C4 0.01 J
0.001 -I
?i
' -L
T
T
I
,
child, dry
*
T-
}i
r
!i .,
11 **t ^
x?<
I
1 J
[
i
L
Hands Legs Arms Faces
Figure 8-3. Gravimetric Loading vs. Body Part for Adult Transplanting Plants in Wet Soil
and for Children Playing in Wet and Dry Soils
June 2000
8-32
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1
2
3
4
5
6
7
8
9
10
11
12
Table 8-19. Summary of Recommended Values For Skin Surface Area
Surface Area
Central Tendency
Upper Percentile
Multiple Percentiles
Whole body
Body parts
see Tables 8-1,8-2, and 8-
4
see Table 8-3
see Tables 8-1,8-2, and
8-4
see Table 8-3
June 2000
8-33
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1
2
3
4
5
Table 8-20. Confidence in Body Surface Area Measurement Recommendations
Considerations
Rationale
Rating
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Study Elements
Level of Peer Review
Accessibility
Reproducibility
Focus on factor of interest
Data pertinent to U.S.
Primary data
Currency
Adequacy of data collection
period
Validity of approach
Representativeness of the
population
Characterization of variability
Lack of bias in study design
Measurement error
Other Elements
Number of studies
Agreement among researchers
Overall Rating
Studies were from peer reviewed journal articles. High
EPA report was peer reviewed before distribution.
The journals used have wide circulation. High
EPA report available from National Technical
Information Service.
Experimental methods are well-described. High
Experiments measured skin area directly. High
Experiments conducted in the U.S. High
Re-analysis of primary data in more detail by two Low
different investigators.
Neither rapidly changing nor controversial area; Low
estimates made in 1935 deemed to be accurate and
subsequently used by others.
Not relevant to exposure factor; parameter not time NA
dependent.
Approach used by other investigators; not challenged High
in other studies.
Not statistically representative of U.S. population. Medium
Individual variability due to age, race, or gender not Low
studied.
Objective subject selection and measurement High
methods used; results reproduced by others with
different methods.
Measurement variations are low; adequately Low/Medium
described by normal statistics.
1 experiment; two independent re-analyses of this Medium
data set.
Consistent results obtained with different analyses; Medium
but from a single set of measurements.
This factor can be directly measured. It is not Medium
subject to dispute. Influence of age, race, or gender
have not been detailed adequately in these studies.
June 2000
8-34
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1
2
>
4
5
6
7
8
9
10
Table 8-21.
Considerations
Study Elements
Level of Peer Review
Accessibility
Reproducibility
Focus on factor of interest
* Data pertinent to U.S.
Primary data
Confidence in Soil Adherence to Skin Recommendations
Rationale
Studies were from peer reviewed journal articles.
Articles were published in widely circulated
journals.
Reports clearly describe experimental method.
The goal of the studies was to determine soil
adherence to skin.
Experiments were conducted in the U.S.
Experiments were directly measure soil adherence to
Rating
High
High
High
High
High
High
11 Currency
12 Adequacy of data collection
13 period
14 Validity of approach
Representativeness of the
population
17 Characterization of variability
18 Lack of bias in study design
19 Measurement error
20 Other Elements
21 Number of studies
22 Agreement among researchers
23 Overall Rating
skin; exposure and dose of chemicals in soil were
measured indirectly or estimated from soil contact.
New studies were presented. High
Seasonal factors may be important, but have not been Medium
studied adequately.
Skin rinsing technique is a widely employed High
procedure.
Studies were limited to the State of Washington and Low
may not be representative of other locales.
Variability in soil adherence is affected by many Low
factors including soil properties, activity and
individual behavior patterns.
The studies attempted to measure soil adherence in High
selected activities and conditions to identity
important activities and groups.
The experimental error is iow and well controlled, Low/High
but application of results to other similar activities
may be subject to variation.
The experiments were controlled as they were Medium
conducted by a few laboratories; activity patterns
were studied by only one laboratory.
Results from key study were consistent with earlier Medium
estimates from relevant studies and assumptions, but
are limited to hand data.
Data are limited, therefore it is difficult to Low
extrapolate from experiments and field observations
to general conditions.
June 2000
8-35
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APPENDIX 8A
FORMULAE FOR TOTAL BODY SURFACE AREA
June 2000
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1 APPENDIX 8A
2 FORMULAE FOR TOTAL BODY SURFACE AREA
3 . .
4 Most formulae for estimating surface area (SA), relate height to weight to surface area. The
5 following formula was proposed by Gehan and George (1970):
6
7 SA-KW2/3 (8A-1)
8 bA-KW
9 where:
10
11 SA = surface area in square meters;
12 W = weight in kg; and
13 K = constant.
14
15 While the above equation has been criticized because human bodies have different
16 specific gravities and because the surface area per unit volume differs for individuals with
17 different body builds, it gives a reasonably good estimate of surface area.
18
19 A formula published in 1916 that still finds wide acceptance and use is that of DuBois
20 and DuBois. Their model can be written:
21
SA = a0Ha W ~ (8A-2)
2 where:
23 .
24 SA = surface area in square meters;
25 H = height in centimeters; and
26 W = weight in kg.
27 .
28 The values of ao (0.007182), a, (0.725), and a, (0.425) were estimated from a sample of
29 only nine individuals for whom surface area was directly measured. Boyd (1935) stated that the
30 Dubois formula was considered a reasonably adequate substitute for measuring surface area.
31 Nomograms for determining surface area from height and mass presented in Volume I of the
32 Geigy Scientific Tables (1981) are based on the DuBois and DuBois formula. In addition, a
33 computerized literature search conducted for this report identified several articles written in the
34 last 10 years in which the DuBois and DuBois formula was used to estimate body surface area.
35 Boyd (1935) developed new constants for the DuBois and DuBois model based on
36 231 direct measurements of body surface area found in the literature. These data were limited to
37 measurements of surface area by coating methods (122 cases), surface integration (93 cases), and
38 triangulation (16 cases). The subjects were Caucasians of normal body build for whom data on
39 weight, height, and age (except for exact age of adults) were complete. Resulting values for the
40 constants in the DuBois and DuBois model were % = 0.01787, a, = 0.500, and a, = 0.4838. Boyd
41 also developed a formula based exclusively on weight, which was inferior to the DuBois and
42 DuBois formula based on height and weight.
3 Gehan and George (1970) proposed another set of constants for the DuBois and DuBois
4 model. The constants were based on a total of 401 direct measurements of surface area, height,
June 2000 8A-1 DRAFT-DO NOT QUOTE OR CITE
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1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25'
26
27
28
29
30
31
32
33
34
and weight of all postnatal subjects listed in Boyd (1935). The methods used to measure these
subjects were coating (163 cases), surface integration (222 cases), and triangulation (16 cases).
Gehan and George (1970) used a least-squares method to identify the values of the
constants. The values of the constants chosen are those that minimize the sum of the squared
percentage errors of the predicted values of surface area. This approach was used because the
importance of an error of 0.1 square meter depends on the surface area of the individual. Gehan
and George (1970) used the 401 observations summarized in Boyd (1935) in the least-squares
method. The following estimates of the constants were obtained: % = 0.02350, a, = 0.42246,
and a2 = 0.51456. Hence, their equation for predicting SA is:
SA-0.02350 Hฐ-42246W0'51456
(8A-3)
or in logarithmic form:
lnSA= -3.75080= 0.422461nH = 0.514561nW
(8A-4)
where:
SA =
H =
W =
surface area in square meters;
height in centimeters; and
weight in kg.
This prediction explains more than 99 percent of the variations in surface area among the
401 individuals measured (Gehan and George, 1970).
The equation proposed by Gehan and George (1970) was determined by the U.S. EPA
(1985) as the best choice for estimating total body surface area. However, the paper by Gehan
and George gave insufficient information to estimate the standard error about the regression.
Therefore, the 401 direct measurements of children and adults (i.e., Boyd, 1935) were reanalyzed
in U.S. EPA (1985) using the formula of Dubois and Dubois (1916) and the Statistical
Processing System (SPS) software package to obtain the standard error.
The Dubois and Dubois (1916) formula uses weight and height as independent variables
to predict total body surface area (SA), and can be written as:
(8A-5)
or in losarithmic form:
ln(SA)j =
(8A-6)
June 2000
8A-2
DRAFT-DO NOT QUOTE OR CITE
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1 where:
2
'3 Sai = surface area of the i-th individual (m2);
4 Hi = height of the i-th individual (cm);
5 Wi = weight of the i-th individual (kg);
6 HO, a,, and a2 - parameters to be estimated; and
7 es = a random error term with mean zero and constant variance.
8
9
10 Using the least squares procedure for the 401 observations, the following parameter
11 estimates and their standard errors were obtained:
12
13
a0 =-3.73(0.18)^1 =0.417(0.054)^2 =0-517(0.022)
14 The model is then:
15
SA = 0.0239Hฐ-417Wฐ-517 <*A-7)
16
17
18 or in logarithmic form:
9
0
In SA =-3.73 + 0.417 In H+0.517 In W (8A-.8)
21
22 with a standard error about the regression of 0.00374. This model explains more than 99 percent
23 of the total variation in surface area among the observations, and is identical to two significant
24 figures with the model developed by Gehan and George (1970).
25 When natural logarithms of the measured surface areas are plotted against natural
26 logarithms of the surface predicted by the equation, the observed surface areas are symmetrically
27 distributed around a line of perfect fit, with only a few large percentage deviations. Only five
28 subjects differed from the measured value by 25 percent or more. Because each of the five
29 subjects weighed less than 13 pounds, the amount of difference was small. Eighteen estimates
30 differed from measurements by 15 to 24 percent. Of these, 12 weighed less than 15 pounds each,
31 1 was overweight (5 feet 7 inches, 172 pounds), 1 was very thin (4 feet 11 inches, 78 pounds),
32 and 4 were of average build. Since the same observer measured surface area for these 4 subjects,
33 the possibility of some bias in measured values cannot be discounted (Gehan and George 1970).
34 Gehan and George (1970) also considered separate constants for different age groups:
35 less than 5 years old, 5 years oid to less than 20 years old, and greater than 20 years old. The
36 different values for the constants are presented below:
37
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1
2
3
4
Table 8A-1. Estimated Parameter Values for Different Age Intervals
8
9
10
11
12
13
14
15
1.6
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Age
group
All ages
<5 years old
> 5 - <20 years old
> 20 years old
Number
of persons
401
229
42
30
a<>
0.02350
0.02667
0.03050
0.01545
a
0.42246
0.38217
0.35129
0.54468
a,
0.51456
0.53937
0.54375
0.46336
The surface areas estimated using the parameter values for all ages were compared to
surface areas estimated by the values for each age group for subjects at the 3rd, 50th, and
97th percentiles of weight and height. Nearly all differences in surface area estimates were less
than 0.01 square meter, and the largest difference was 0.03 nr for an 18-year-old at the
97th percentile. The authors concluded that there is no advantage in using separate values of ao,
a,, and a, by age interval.
Haycock et ai. (1978) without knowledge of the work by Gehan and George (1970),
developed values for the parameters a0, a,, and a, for the DuBois and DuBois model. Their
interest in making the DuBois and DuBois model more accurate resulted from their work in
pediatrics and the fact that DuBois and DuBois (1916) included only one child in their study
group, a severely undernourished girl who weighed only 13.8 pounds at age 21 months. Haycock
et al. (1978) used their own geometric method for estimating surface area from 34 body
measurements for 81 subjects. Their study included newborn infants (10 cases), infants
(12 cases), children (40 cases), and adult members of the medical and secretarial staffs of
2 hospitals (19 cases). The subjects all had grossly normal body structure, but the sample
included subjects of widely varying physique ranging from thin to obese. Black, Hispanic, and
white children were included in their sample. The values of the model parameters were solved
for the relationship between surface area and height and weight by multiple regression analysis.
The least squares best fit for this equation yielded the following values for the three coefficients:
^ = 0.024265, a, = 0.3964, and a, = 0.5378. The result was the following equation for
estimating surface area:
SA=0.024265Hฐ-3964W0-5378
expressed logarithmically as:
In SA = In 0.024265 + 0.3964 In H + 0.5378 In W
(8A-9)
(8A-10)
The coefficients for this equation agree remarkably with those obtained by Gehan and George
(1970) for 401 measurements.
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1 George et al. (1979) agree that a model more complex than the model of DuBois and"
2 DuBois for estimating surface area is unnecessary. Based on samples of direct measurements by
3 Boyd (1935) and Gehan and George (1970), and samples of geometric estimates by Haycock
4 et al. (1978), these authors have obtained parameters for the DuBois and DuBois model that are
5 different than those originally postulated in 1916. The DuBois and DuBois model can be written
6 logarithmically as:
lnSA = lnaQ-aj lnH + a2 InW
7
8
9 The values for a0, a,, and a, obtained by the various authors discussed in this section are
10 presented to follow:
11
12 Table 8A-2. Summary of Surface Area Parameter Values for the Dubois and Dubois Model
13
14
15
16
17
18
19
|20
21
22 . '
23
24 The agreement between the model parameters estimated by Gehan and George (1970) and
25 Haycock et al. (1978) is remarkable in view of the fact that Haycock et al. (1978) were unaware
26 of the previous work. Haycock et al. (1978) used an entirely different set of subjects, and used
27 geometric estimates of surface area rather than direct measurements. It has been determined that
28 the Gehan and George model is the formula of choice for estimating total surface area of the
29 body since it is based on the largest number of direct measurements.
30
31 Nomograms
32 Sendroy and Cecchini (1954) proposed a graphical method whereby surface area could be
33 read from a diagram relating height and weight to surface area. However, they do not give an
34 explicit model for calculating surface area. The graph was developed empirically based on
35 252 cases, 127 of which were from the 401 direct measurements reported by Boyd (1935). In the
36 other 125 cases the surface area was estimated using the linear method of DuBois and DuBois
37 (1916). Because the Sendroy and Cecchini method is graphical, it is inherently less precise and
38 less accurate than the formulae of other authors discussed above.
Author
(year)
DuBois and DuBois
(1916)
Boyd (1935) -
Gehan and George
(1970)
Haycock etal. (1978)
Number
of persons
. 9
231
401
81
a0
0.007184
0.01787
0.02350
0.024265
a,
0.725
0.500
0.42246
0.3964
a2
0.425
0.4838
0.51456
0.5378
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1 9. ACTIVITY FACTORS
2
3 9.1 INTRODUCTION
4 As a consequence of a child's immaturity and small stature, certain activities and
5 behaviors specific to children place them at higher risk to certain environmental agents (Chance
6 and Harmsen, 1998). Individual or group activities are important determinants of potential
7 exposure because toxic chemicals introduced into the environment may not cause harm a child
8 until an activity is performed subjecting the child to contact with those contaminants. An
9 activity or time spent will vary based on. for example, culture, hobbies, location, gender, age, and
] 0 personal preferences. It is difficult to accurately collect/record data for a child's activity patterns
11 (Hubal et al., 1999). Children engage in more contact activities than adults, therefore, a much
12 wider distribution of activities need to be considered when assessing exposure (Hubal et al.,
13 2000). Behavioral patterns and preferred activities results in different exposures than for adults,
14 but also for children of different developmental stages (Chance and Harmsen, 1998).
15 The purpose of this section is to provide information on various activities, length of time
fl6 spent performing these activities, and locations and length of time spent by individuals within
17 those various microenvironments. This section summarizes data on how much time children
i 8 spend participating in various activities, in various microenvironments, and on the frequency of
19 performing various activities. These data cover a wide scope of activities and populations
20 arranged by age group, when available.
21 '.
22 9.2 ACTIVITY PATTERNS
23
The purpose of this section is to describe published time use studies that provide
24 information on time-activity patterns of children in the U.S. These studies are briefly described
25 below. For a detailed description of the studies, the reader is referred to the Exposure Factors
26 Handbook. Volume III (U.S. EPA. 1997).
27 Timmer et al. (1985) - How Children Use Time - Timmer et al. (1985) conducted a study
28 using the data obtained on children's time use from a 1981 -1982 Panel study. A total of 922
29 children participated in the survey. The children surveyed were between the ages of 3 and 17
years using a time diary and a standardized interview. The time diary involved children
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1 reporting their activities beginning at 12.00 a.m. the previous night; the duration and location of
2 each activity; the presence of another individual; and whether they were performing other
3 activities at the same time. The standardized interview administered to the children was to gather
4 information about their psychological, intellectual (using reading comprehension tests), and
5 emotional well-being; their hopes and goals; their family environment; and their attitudes and
6 beliefs.
7 The mean time spent performing major activities on weekdays and weekends by age and
8 sex, and type of day is presented in Table 9-1. On weekdays, children spend about 40 percent of
9 their time sleeping, 20 percent in school, and 10 percent eating, washing, dressing, and
10 performing other personal activities (Timmer et al., 1985). The data in Table 9-1 indicate that
11 girls spend more time than boys performing household work and personal care activities, and less
12 time playing sports. Also, children spend most of their free time watching television. Table 9-2
13 presents the mean time children spend during weekdays and weekends performing major
14 activities by five different age groups. Also, the significant effects of each variable (i.e., age,
15 sex) are shown in Table 9-2. Older children spend more time performing household and market
16 work, studying and watching television, and less time eating, sleeping, and playing. Timmer
17 et al. (1985) estimated that on the average, boys spend 19.4 hours a week watching television and
18 girls spend 17.8 hours per week performing the same activity.
19 A limitation associated with this study is that it was conducted in 1981 and there is a
20 potential that activity patterns in children may have changed significantly from 1981 to the
21 present. Thus, application of these data for current exposure assessment may bias exposure
22 assessment results.' Another limitation is that the data do not provide overall annual estimates of
23 children's time use since data were collected only during the time of the year when children
24 attend school and not during school vacation.
25 EPA estimated the total time indoors and outdoors using the Timmer data. Activities
26 performed indoors were assumed to include household work, personal care, eating, sleeping,
27 school, studying, attending church, watching television, and engaging in household
28 conversations. The average times spent in these indoor activities, and half the time spent in each
29 activity which could have occurred indoors or outdoors (i.e., market work, sports, hobbies, art
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1 activities, playing, reading, and other passive leisure) were summed. Table 9-3 summarizes the
2 results of this analysis by age groups and day of the week.
3 Robinson and Thomas (1991) - Time Spent in Activities, Locations, and
4 Microenvironments: A California-National Comparison - Robinson and Thomas (1991)
5 reviewed and compared data from the 1987-88 California Air Resources Board (CARB) time
6 activity study for California residents and from a similar 1985 national study, American's Use of
1 Time. Both studies used the diary approach data. Time use patterns were collected for
8 individuals 12 years and older. Telephone interviews based on the random-digit-dialing
9 procedure were conducted for approximately 1,762 respondents. Data categorized for children 0-
10 18 years old were not provided in the study. In addition, Robinson and Thomas (1991) defined a
11 set of 16 microenvironments based on the activity and location codes employed in both studies.
12 The mean duration of time spent for the total sample population, 12 years and older in three
13 location categories is presented in Table 9-4 for both studies. Based on the data shown in Table
14 9-4, respondents spent most of their time indoors, 1255 and 1279 minutes/day for the CARB and
15 national study, respectively.
6 Table 9-5 presents the mean duration of time and standard mean'error for the
17 16 microenvironments grouped by total sample population and gender. Also included is the
18 mean time spent for respondents ("Doers") who reported participating in each activity. Table 9-5
19 - shows that in both studies males spend more time in work locations, automobiles and other
20 vehicles, autoplaces (garages), and physical outdoor activities, outdoor sites. In contrast, females
21 spend more time cooking, engaging in other kitchen activities, performing other chores, and
22 shopping. The same trends also occur on a per participant basis.
23 Table 9-6 shows the mean time spent in various microenvironments grouped by type of
24 day (weekday or weekend) in both studies. Generally, respondents spent most of their time
25 during the weekends in restaurants/bars (CARB study), motor vehicles, outdoor activities,
26 social-cultural settings, leisure/communication activities, and sleeping. Microenvironmental
27 differences by age are presented in Table 9-7.
28 Limitations associated with the Robinson and Thomas (1991) study are that the CARB
29 survey was performed in California only. Therefore, if applied to other populations, the data set
may be biased. In addition, the studies were conducted in 1980s and may bias exposure
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1 assessment results when used for current exposure assessments. Another limitation is that time
2 distribution patterns were not provided for both studies and the data are based on short-term
3 studies.
4 Wiley et al. (1991) - Study of Children's Activity Patterns - The California children's
5 activity pattern survey design provided time estimates of children (under 12 years old) in various
6 activities and locations (microenvironments) on a typical day (Wiley et al., 1991). A total of
7 1,200 children were included in the study. The average time respondents spent during the 10
8 activity categories for all children are presented in Table 9-8. Also included in this table are the
9 detailed activity, including its code, with the highest mean duration of time; the percentage of
10 respondents who reported participating in any activity (percent doing); and the mean, median,
11 and maximum time duration for "doers." The dominant activity category, personal care (night
12 sleep being the highest contributor), had the highest time expenditure of 794 mins/day (13.2
13 hours/day). All respondents reported sleeping at night, resulting in a mean daily time per
14 participant of 794 mins/day spent sleeping. The activity category "don't know" had a duration of
15 about 2 mins/day and only 4 percent of the respondents reported missing activity time.
16 Table 9-9 presents the mean time spent in the 10 activity categories by age and gender.
17 Differences in activity patterns for boys and girls tended to be small. Table 9-10 presents the
18 mean time spent in the 10 activity categories grouped by seasons and California regions. There
19 were seasonal differences for 5 activity categories: personal care, educational activities,
20 social/entertainment, recreation, and communication/ passive leisure. Time expenditure
21 differences in various regions of the State were minimal for childcare, work-related activities,
22 shopping, personal care, education, social life, and recreation.
23 Table 9-11 presents the distribution of time across six location categories. The
24 participation rates (percent) of respondents, the mean, median, and maximum time for "doers."
25 The detailed location with the highest average time expenditure are also shown. The largest
26 amount of time spent was at home (1,078 minutes/day); 99 percent of respondents spent time at
27 home (1,086 minutes/ participant/day). Tables 9-12 and 9-13 show the average time spent in the
28 six locations grouped by age and gender, and season and region, respectively. There are age
29 differences in time expenditure in educational settings for boys and girls (Table 9-12). There are
30 no differences in time expenditure at the six locations by regions, and time spent in school
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1 decreased in the summer months compared to other seasons (Table 9-13). Table 9-14 shows the
2 average potential exposure time children spent in proximity to tobacco smoke, gasoline fumes,
3 and gas oven fumes grouped by age and gender. The sampled children spent more time closer to
4 ' tobacco smoke (77 mins/day) than gasoline fumes (2 mins/day) and gas oven fumes
5 (11 mins/day).
6 EPA estimated the total time indoors and outdoors using the data from the Wiley study.
7 Activities performed indoors, were assumed to include household, childcare, personal needs and
8 care, education, and communication and passive leisure. The average times spent in these indoor
9 activities, and half the time spent in each activity which could have occurred indoors or outdoors
10 (i.e., work-related, goods/services, organizational activities, entertainment/social, don't know/not
11 coded) were summed. Table 9-15 summarizes the results of this analysis by age groups.
12 U.S. EPA (1992) - Dermal Exposure Assessment: Principles and Applications - U.S.
13 EPA (1992) addressed the variables of exposure lime, frequency, and duration needed to
14 calculate dermal exposure as related to activity. The reader is referred to the document for a
15 detailed discussion of these variables in relation to soil and water related activities. The
16 suggested values that can be used for dermal exposure are presented in Table 9-16. Limitations
17 of this study are that the values are based on small data sets and a limited number of studies.
18 These data are not representative for children in specific age group categories. An advantage is
19 that it presents default values for frequency and duration for use in exposure assessments when
20 specific data are not available.
21 Davis (1995). Soil Ingestion in Children with Pica (Final Report), EPA Cooperative
22 Agreement CR 816334-01 - In 1992, the Fred Hutchinson Cancer Research Center under
23 Cooperative Agreement with EPA conducted a study to estimate soil intake rates and collect
24 mouthing behavior data. Originally, the study was designed with two primary purposes: 1) to
25 describe and quantify the distribution of soil ingestion values in a group of children under the age
26 of five who exhibit behaviors that would be likely to result in the ingestion of larger than normal
27 amounts of soil; and 2) to assess and quantify the degree to which soil ingestion varies among
28 children according to season of the year (summer vs. winter).
29 The study was conducted during the first four months of 1992 and included 92 children
JO from the Tri-Cities area in Washington State. Children ranged in age from 10 to 60 months.
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1
2
^
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
These children were volunteers among a group selected through random digit dialing. The study
was conducted during a period of 7 days.
In addition to mouthing behavior data, information was collected about how long the
child spent indoors and outdoors each.day, and the general types of outdoor settings the child
played in. Figure 9-1 presents the distribution of the number of hours per day study children
spent indoors at home. Values were: the mean was 8.9 hours, the median was 9 hours, and the
range was 30 minutes to 1.5 hours. Figure 9-2 presents the distribution of the number of hours
per day study children spent indoors away from home. The mean number of hours spent indoors
away from home was 1.8, the median was 1, and the range was 0-15 hours. Figure 9-3 presents
the distribution of number of hours per day study children spent outdoors at home. The mean
number of hours spent outdoors at home was 1.4, the median was 45 minutes, and the range was
0-9 hours. Figure 9-4 presents the number of hours per day study children spent outdoors away
from home. The mean number of hours spent was approximately 30 minutes, the median was
less than 15 minutes, and the range was 0-8 hours.
Tsang and Klepeis (1996) - National Human Activity Pattern Survey (NHAPS) - The
National Human Activity Pattern Survey was conducted by the U.S. EPA (Tsang and Klepeis,
1996). It is the largest and most current human activity pattern survey available (Tsang and
Klepeis. 1996). Data were collected on duration and frequency of selected activities and of the
time spent in selected microenvironments. In addition, demographic information was collected
for each respondent to allow for statistical summaries to be generated according to specific
subgroups of the U.S. population (i.e., by gender, age. race, employment status, census region,
season, etc.). The participants' responses were weighted according to geographic,
socioecoriomic, time/season, and other demographic factors to ensure that results were
representative of the U.S. population.
Tables 9-17 through 9-47 provide data from the NHAPS study. Tables 9-17 through 9-31
present data on the amount of time spent in selected activities and/or the corresponding
distribution data, when available.
Table 9-17 presents number of times taking a shower at specified daily frequencies
by number of respondents. The data shows that the majority of respondents take a
shower one or two times a day.
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1 Table 9-18 provides time spent taking a shower and time spent in the shower room
2 immediately after showering. Most of the respondents spent 10-20 minutes taking a
3 shower and in the shower room after showering.
4
5 Table 9-19 provides the percentile data for the same activity shown in Table 9-16.
6 . The 50th percentile value is 10 minutes for showering and 5 minutes for time spent
7 after showering was complete. The 90th percentile values vary across age groups and
8 range from 30-35 minutes and 10-15 minutes for time spent showering and in the
9 bathroom after showering, respectively.
10
11 Table 9-20 presents total time (minutes) spent in the shower or bathtub and in the
12 bathroom immediately after a shower or bath. The majority of respondents spent
13 from 10-20 minutes in the shower or bathtub and approximately 10 minutes in the
14 bathroom afterwards.
15
16 Table 9-21 presents the percentile data for the same activity shown in Table 9-18.
17 The 50th percentile values range from 15-20 minutes and 2-5 minutes for taking a
18 shower or bath and time spent in the bathroom after the bath, respectively.
19
20 Table 9-22 provides a range of number of times washing the hands in a day. Most
21 respondents washed their hands 3-5 times a day.
22
L23 Table 9-23 presents statistics data for the number of minutes per day spent working
14 or being near excessive dust in the air. For age groups 1-11 years old, the 50th
25 percentile data indicates that approximately 75 minutes/day is spent in air with
26 excessive dust.
27
28 Table 9-24 provides data for the frequency of starting a motor vehicle in a garage or
29 carport and started with the garage door closed.
30
31 Table 9-25 provides data for the range of minutes/day spent playing on sand, gravel.
32 dirt, or grass and playing when fill dirt was present.
*t -^
jj
34 Table 9-26 provides the percentile data for the same activity shown in Table 9-25.
35
36 Table 9-27 presents data for time (minutes/day) spent playing on the grass by numbei
37 of respondents. The majority of respondents spent more than 120 minutes/day in this
38 activity.
39
40 Table 9-28 presents percentile data for the same activity shown in Table 9-27. The
41 50th percentile rate is 60 minutes/day for all age groups.
42
43 Table 9-29 provides number of times/month swimming in a freshwater swimming
44 pool by number of respondents. The majority of respondents swim in freshwater
f-5 pools 1 or 2 times/month.
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1
2
*>
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26'
27
28
29
30
31
32
"i "*
jj
34
35
36
37
38
39
40
41
42
Table 9-30 provides percentile data for the same activity shown in Table 9-29. The
50th percentile values are 42.5 minutes/month for age group 1-4 years and 60
minutes/month for age gropus 5-11 and 12-17 years.
Table 9-31 presents the range of the average amount of time (minutes/month)
actually spent in the water by swimmers. The majority of swimmers spent an average
of 50-60 minutes/month in the water.
Tables 9-32 through 9-44 provide statistics for 24-hour cumulative time (minimum,
mean, maximum) spent in selected activities. The minimum is the minimum number of minutes
spent in the activity. The mean is the mean 24-hour cumulative number of minutes spent by
doers. The maximum is the maximum number of minutes spent in the activity. The percentiles
are the percentage of doers bejow or equal to the given number of minutes.
Table 9-32 provides number of minutes spent playing indoors and playing outdoors.
Table 9-33 provides number of minutes spent sleeping/napping in a day.
Table 9-34 presents data for time spent attending full-time school.
Table 9-35 provides data for time spent in active sports and for time spent in
sports/exercise.
Table 9-36 presents data for time spent in outdoor recreation and for walking.
Table 9-37 provides data for time spent bathing.
Table 9-38 presents statistics for minutes eating or drinking.
Table 9-39 provides data for time spent indoors at school and in a restaurant.
Table 9-40 provides information for time spent outdoors on school
; grounds/playgrounds and at a pool/river/lake.
Table 9-41 provides information on time spent at home in the kitchen, bathroom, and
bedroom, and indoors in a residence (all rooms).
Table 9-42 presents data for time spent traveling inside a vehicle.
Table 9-43 provides data for time spent outdoors (outside the residence) and outdoor
other than near a residence such as parks, golf courses, or farms.
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1 Table 9-44 provides information for time spent in malls, grocery stores, and other
2 stores.
3
4 Table 9-45 presents data for minutes spent with smokers present.
5
6 Table 9-46 provides data for time (minutes) spent smoking by number of
7 respondents.
8
9 Table 9-47 provides percentile data for the same activity shown in Table 9-44.
10
11
12 Advantages of the NHAPS dataset are that it is representative of the U.S. population and
13 it has been adjusted to be balanced geographically, seasonally, and for day/time. Also, it is
14 representative of all ages, gender, and is race specific. A disadvantage of the study is that for
15 ages 1-17, the "N" is small for most activities. In addition, means cannot be calculated for time
16 spent over 60,120, and 181 minutes in selected activities. Therefore, actual time spent at the
17 high end of the distribution for these activities cannot be captured.
18 Funk et al. (1998) - Quantifying the Distribution of Inhalation Exposure in Human
19 Populations - Funk et al. (1997) used the data from the California Air Resources Board (CARB)
study to determine distributions of exposure time by tracking the time spent participating in daily
21 at home and at school activities for male and female children and adolescents. CARB performed
22 two studies from 1987 to 1990; the first was focused on adults and adolescents (12-17 years old),
23 while the second focused on children (6-11 years old) (Funk et al., 1998). The targeted groups
24 were noninstitutiorialized English speaking Califomians with a telephone in their residence.
25 Individuals were contacted by telephone and asked to account for every minute within the
26 previous 24 hours, including the amount of time spent on an activity and the location of the
27 activity. The surveys varied from day to day and season to season.
28 All the activities that were documented were separated into two groups, "at home" (any
29 activity at principal residence), or "away." Each activity was assigned to one of three ventilation
30 levels (Ve)? low. moderate, or high. Resting activities were placed in the low Ve, and moderate
31 exertion activities were assigned to moderate Ve. Activities requiring high levels of physical
32 exertion were placed in the high Ve group. Ambiguous activities that were encountered were
33 assigned to moderate ventilation levels. Among the adolescents and children studied, means
were determined for the aggregate age groups, as shown in Table 9-48.
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1 Several statistical methods, such as Chi-quare, Kolmogorov,-Smirnov, and Anderson-
2 Darling, were used to determine whether the time spent in an activity group had a known
3 distribution (Funk et al., 1998). All the activities that were identified in the C ARB study were
4 assigned to the three ventilation levels. Most of the activities performed by children were low to
5 moderate Ve as shown in Table 9-49.
6 The aggregate time periods spent at home in each activity are shown in Table 9-50.
7 Aggregate time spent at home performing different activities was compared between genders.
8 There were no significant differences between adolescent male and females in any of the activity
9 groups (Funk et al., 1998) (Table 9-51). In children ages 6-11 years there were differences found
10 between gender and age at the low ventilation levels. In the moderate ventilation level there
11 were significant differences between two age groups (6-8 years, and 9-11 years) and gender
12 (Funk etal., 1998) (Table 9-52).
13 Large proportions of the respondents in the study did not participate in high ventilation
14 activities; discrete distributions were used to characterize high ventilation activity groups (Funk
15 et al., 1998). Lognormal distribution best described the time spent by children at high ventilation
16 levels.
17 Hubal et al. (2000) - Children's Exposure Assessment: A Review of Factors Influencing
18 Children's Exposure, and the Data Available to Characterize and Assess that Exposure - Hubal
19 et al. (2000) reviewed available data to characterize and assess environmental exposures to
20 children. As part of that review, available activity patterns data were evaluated. Hubal reviewed
21 the EPA National Exposure Research Laboratory's Consolidated Human Activity Database
22 (CHAD), which contains data from several studies on human activities. For children and
23 adolescents younger than 18 years. CHAD contains 4.300 person-days of information and 3.009
24 person-days of microactivity data for 2,640 children less than 12 years old (Hubal et al., 2000)
25 (Table 9-53). Specific examples of the type of microactivity data available in CHAD for
26 children are shown in Tables 9-54 and 9-55. The number of hours spent in various
27 microenvironments are shown in Table 9-54 and time spent in various activities indoors at home
28 in Table 9-55.
29 The authors noted that CHAD contains approximately "140 activity codes and 110
30 location codes, but the data generally are not available for all activity locations for any single
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1 respondent. In fact, not all of the codes were used for most of the studies. Even though many
2 codes are used in macroactivity studies, many of the activity codes do not adequately capture the
3 richness of what children actually do. They are much too broadly defined and ignore many
4 child-oriented behaviors. Thus, there is a need for more and better-focused research into
5 children's activities." CHAD is available on the EPA Intranet (Hubal et al., 2000).
6
7 9.3 RECOMMENDATIONS
8 Assessors are commonly interested in a number of specific types of time use data
9 including time/frequencies for bathing, showering, gardening, residence time, indoor versus
10 outdoor time, swimming, occupational tenure, and population mobility. Recommendations for
11 - each of these are discussed below. The confidence in the recommendations for activity patterns
12 is presented in Table 9-56.
13
14 9.3.1 Recommendations for Activity Patterns
15 This chapter presents several studies that provide data on activity patterns. Table 9-57
6 summarizes information on the various studies. Recommendations for selected activities
17 commonly used in exposure assessments and known to increase exposure to certain chemicals
18 are provided to follow. These activities are time spent indoors versus outdoors, showering,
19 swimming, residential time spent indoors and outdoors, time spent playing on sand and gravel,
20 and time spent playing on grass.
21 Time Spent Indoors Versus Outdoors - Assessors often require knowledge of time
22 individuals spend indoors versus outdoors. Ideally, this issue would be addressed on a site-
23 specific basis since the times are likely to vary considerably depending on the climate, residential
24 setting (i.e., rural versus urban), personal traits (i.e., age. health) and personal habits.
25 Activities can vary significantly with differences in age. Table 9-58 summarizes the
26 studies that present information on time indoors and outdoors. Of these studies, Timmer et al.
27 (1985) in addition to being a national study, presents the data for a more comprehensive set of
28 age groupings for children. Timmer et al. (1985) presented data on time spent in various
29 activities for boys and girls ages 3-17 years. This national study focused on activities performed
indoors such as household work, personal care, eating, sleeping, school, studying, attending
June 2000 9-11 DRAFT-DO NOT QUOTE OR CITE
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1 church, watching television, and engaging in household conversations. The average times spent
2 in each activity, and half the times spent in each activity which could have occurred indoors or
3 outdoors, were summed. The results are presented in Table 9-59 For various age groups.
4 Although there is good agreement between the Robinson Thomas 1991 and Timmer 1985
5 studies, the recommendations are based on the Timmer study because it provides data for
6 younger children. The recommendations are based on the. Timmer data shown in Table 9-58.
7 Showering - The recommended shower frequency of one shower per day is based on the
8 NHAPS data summarized in Table 9-17. This table showed that 341 of the 451 total participants
9 indicated taking at least one shower the previous day.
10 Recommendations for showering duration are based on the study of Tsang and Klepeis
11 (1996). A recommended value for average showering time is 10 minutes.(Table 9-18) based on
12 professional judgement.
13 Swimming - Data for swimming frequency is taken from the NHAPS Study (Tsang and
14 Klepeis, 1996). Of the 653 participants, who answered yes to the question "in the past month,
15 did you swim in a freshwater poo!?", 241 were ages 1-17 years. The results to this question are
16 summarized in Table 9-29. The recorded number of times respondents swam in the past month
17 ranged from 1 to 60 with the greatest number of respondents reporting they swam one time per
18 month. Thus, the recommended swimming frequency is one event/ month. The recommended
19 swimming duration, 60 minutes per swimming event, is based on the NHAPS distribution shown
20 on Table 9-30. Sixty minutes is based on an average of the 50th percentile values. The 90th
21 percentile value is 180 minutes per swimming event (based on one event/month); and the 99th
22 percentile value is 181 minutes. This value (181) indicates that more than 180 minutes were
23 spent.
24 Residential Time Spent Indoors and Outdoors - The recommendations for time spent
25 indoors at one's residence for children 1-17 years old is 18 hours/day. This is based on the
26 NHAPS data summarized in Table 9-41 for number of minutes spent indoors in a residence (all
27 rooms). The average of the 50th percentile values for all age groups is 1.061 minutes per day
28 (17.7 hours/day); and a 90th percentile value of 1,361 minutes per day (22.6 hours/day).
29 The recommended value for time spent outdoors outside one's residence is 2 hours per
30 day based on NHAPS data shown on Table 9-43 for time spent outdoors (outside the residence).
June 2000 9-12 DRAFT-DO NOT QUOTE OR CITE
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The 50th percentile values range from 100-150 minutes/day and the 90th percentile values range
from 300-400 minutes/day as shown in Table 9-43.
Playing on Sand or Gravel, and on Grass - The recommended value for time spent
playing on sand or gravel is 60 minutes/day. This value is based on NHAPS data shown in Table
9-25. This recommendation is based on professional judgement. The data in Table 9-25, show
that the majority of respondents are captured in the 0-0 minutes/day category. However, for the
other time categories, the majority of respondents are captured in the 50-60 minutes/day
category.
9 The recommended value for time spent playing on grass is 60 minutes/day based on the
0 50th percentile data shown in Table 9-28 and the 50-60 minutes/day category data in Table 9-27.
.1
1
>2
"i
4
5
6
7
8 category.
10
11
12 9.3.2 Summary of Recommended Activity Factors
Table 9-59 includes a summation of the recommended activity pattern factors presented
in this section and the studies which provided data on the specific activities. The type of
activities include indoor activities, outdoor activities, taking a shower, swimming, time spent
playing on sand or gravel, and time spent playing on grass.
13
1 4
15
June 2000 9-13 DRAFT-DO NOT QUOTE OR CITE
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1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
9.4 REFERENCES FOR CHAPTER 9
Chance, W.G.; Harmsen, E. (1998) Children are different: environmental contaminants and children's health.
Canadian Journal of Public Health, Vol. 89, Supplement, pp. 59-513.
Davis, S. (1995) Soil ingestion in children with pica. Final Report. EPA Cooperative Agreement. CR816334.01.
Funk, L.; Sedman, R.; Beals, J.A.J.; Fountain, R. (1998) Quantifying the distribution of inhalation exposure in
human populations: distributions of time spent by adults, adolescents, and children at home, at work, and at
school. Risk Analysis. 18(l):47-56.
Hubal, E.A.; Sheldon, L.S.; Burke, J.M.; McCurdy, T.R.; Berry, M.R.; Rigas, ML.; Zartarian, V.G.; Freeman, N.G.
(2000) Children's exposure assessment: a review of factors influencing children's exposure and the data
available to characterize and assess that exposure. Research Triangle Park, NC: U.S. Environmental Protection
Agency, National Exposure Research Laboratory.
Robinson, J.P; Thomas. J. (1991) Time spent in activities, locations, and microenvironments: a California-National
Comparison Project report. Las Vegas, NV: U.S. Environmental Protection Agency, Environmental Monitoring
Systems Laboratory.
Timmer, S.G.; Eccles, J.; O'Brien, K. (1985) How children use time. In: Juster, F.T.; Stafford, F.P.; eds. Time,
goods, and well-being. Ann Arbor, MI: University of Michigan, Survey Research Center, Institute for Social
Research, pp. 353-380.
Tsang, A.M.; Klepeis, N.E. (1996) Results tables from a detailed analysis of the National Human Activity Pattern
Survey (NHAPS) response. Draft Report prepared for the U.S. Environmental Protection Agency by Lockheed
Martin, Contract No. 68-W6-001, Delivery Order No. 13.
U.S. EPA. (1992) Dermal exposure assessment: principles and applications. Washington, DC: Office of Health
and Environmental Assessment. EPA No. 600/8-91-011B. Interim Report.
U.S. EPA. (1997) Exposure Factors Handbook. Washington, DC: National Center for Environmental Assessment,
Office of Research and Development. EPA/600/P-95/002Fa,b,c.
Wiley, J.A.; Robinson, J.P.; Cheng, Y.: Piazza. T.: Stork, L.: Plasden, K. (1991) Study of children's activity
patterns. California Environmental Protection Agency, Air Resources Board Research Division. Sacramento,
CA.
June 2000
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Table 9-1. Mean Time Spent (minutes) Performing Major Activities Grouped by Age. Sex and Type of Day
>3
4
5
6
7
S
9
10
11
12
13
14
15
16
17
18
I19
lo
21
22
23
24
25
26
27
28
29
30
31
Activity-
Age (3-1 1 years)
Duration of Time (mins/day)
Weekdays
Market Work
Household Work
Personal Care
Eating
Sleeping
School
Studying
Church
Visiting
Sports
Outdoors
Hobbies
An Activities
Playing
TV
Reading
Household Conversations
Other Passive Leisure
NA1
Percent of Time Accounted for
bv Activities Above
a NA = Unknown
Source: Timmeretal.. 1985.
Boys
16
17
43
81
584
252
14
7
16
'25
10
3
4
137
117
9
10
9
22
94%
Girls
0
21
44
78
590
259
19
4
9
12
7
\
4
115
128
7
It
14
25
92%
Weekends
Boys
(n=l 18)
7
32
42
78
625
-
4
53
23
33
30
3
4
177
181
12
14
16
20
93%
Girls
(n-111)
4
43
50
84
619
-
9
61
37
23
23
4
4
166
122
10
9
17
29
89%
Age (12- 17 years)
Duration of Time (mins/day)
Weekdays
Boys
(n=77)
23
16
48
73
504
314
29
3
17
52
10
7
12
37
143
10
21
21
14
93%
Girls
(n=83)
21
40
71
65
478
342
37
7
25
37
10
4
6
13
108
13
30
14
17
92%
Weekends
Boys
(n*77)
58
46
35
58
550
-
25
40
46
65
36
4
11
35
187
12
24
43
10
88%
Girls
(n=83)
25
89
76
75
612
-
25
36
53
26
19
7
9
24
140
19
30
33
4
89%
32
June 2000
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1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Table 9-2
Mean Time Spent (minutes) in Major Activities Grouped by Type of Day for Five Different Age Groups
Time Duration (mins)
Weekday
Age (years)
Activities
Market Work
Personal Care
Household Work
Eating
Sleeping
School
Studying
Church
Visiting
Sports
Outdoor activities
Hobbies
Art Activities
Other Passive Leisure
Playing
TV
Reading
Being read to
NA
3-5
-
41
14
82
630
137
2
4
14
5
4
0
5
9
218
111
5
2
30
6-8
14
49
15
81
595
292
8
9
15
24
9
2
4
1
111
99
5
2
14
9-11
8
40
IS
73
548
315
29
9
10
21
8
2
3
2
65
146
9
0
23
12-14
14
56
27
69
473
344
33
9
21
40 -
7
4
3
6
31
142
'10
0
25
Weekend
15-17
28
60
34
67
499
314
* i
jj
3
20
46
11
6
12
4
14
108
12
0
7
3-5
-
47
17
81
634
-
1
55
10
3
8
1
4
6
267
122
4
3
52
6-8 9-11
4 10
45 44
27 51
80 78
641 596
_
2 12
56 53
8 13
30 42
23 39
5 3
4 4
10 7
180 92
136 185
9 10
2 0
7 14
12-14
29
60
72
68
604
-
15
32
22
51
25
8
7
10
35
169
10
0
4
15-17
48
51
.60
65
562
-
30
37
56
37
26
3
10
18
21
157
IB
0
9
Significant
Effects*
A.S.AxS (F>M)
ATS. AxS (F>M)
A
A
A
A
A (Weekend only)
A.S F)
A
A.S (M>F)
A.S. AxS (M>F)
A
A
A
a Effects are significant for weekdays and weekends, unless otherwise specified A = age effect. P<0.05. for both weekdays and weekend
activities: S - sex effect P<0.05. F>M. M>F = females spend more time than males, or vice versa: and AxS ป age by sex interaction.
P<0-05.
Source: Timmer et al.. 1985.
June 2000
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1
2
t
4
5
6
7
8
9
Table 9-3. Mean Time Spent Indoors
Age Group
(yrs)
3-5
6-8
9-11
12-14
15-17
Time Indoors
Weekday
(hrs/day)
1.94
20.7
20.8
20.7
19.9
and Outdoors Grouped by Age and Day of the Week
Time Indoors
Weekend
(hrs/day)
18.9
18.6
18.6
18.5
17.9
Time Outdoors
Weekday
(hrs/day)
2.5
1.8
1.3
1.6
1.4
Time Outdoors
Weekend
< hrs/day)
3.1
2.5
2.3
1.9
2.3
10
11 Source: Adapted from Timmer et al. (1985).
June 2000 9-17 DRAFT-DO NOT QUOTE OR CITE
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1
2
Table 9-4. Mean Time Spent at Three Locations for both CARB and
National Studies (ages 12 years and older)
4
5
8
9
10
11
12
13
14
15
16
Location Category
Indoor
Outdoor
In-Vehicle
Total Time Spent
CARB
(n = 1762)b
1255'
86*
9งf
1440
Mean duration (mins/day)
National
S.E.1 (n = 2762)ป S.E.
28 1279e 21
5 74d 4
4 ST 2
1440
3 S.E. = Standard Error of Mean
11 Weiehted Number - National samnle oonulation was weighted to obtain a ratio of 46.5 males and 53.5 females, in eaua)
proportion for each day of the week, and for each quarter of the year.
c Difference between the mean values for the CARB and national studies is not statistically significant.
* Difference between the mean values for the CARB and national studies is statistically significant at the 0.05 level.
Source: Robinson and Thomas. 1991.
June 2000
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1
2
3
4
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
^6
27
28
29
30
31
32
34
35
36
37
38
39
40
41
42
43
44
45
46
Table 9-5. Mean Time Spent (minutes/day) in Various Microenvironments Grouped by Total Population
and Gender (12 years and over) in the National and CARfi Data
National Data
Mean Duration (mins/day) (standard error)*
M icroenvironment
Autoplaces
Restaurant/bar
in-vehicle
In-Vehicle/other
Physical/outdoors
Physical/indoors
Work/study-residence
Work/study-other
Cooking
Other activities/kitchen
Chores/child
Shop/errand
Other/outdoors
Social/cultural
Leisure -eat/indoors
Sieep/'mdoors
N = I284b
Male
5(1)
22(2)
92(3)
1(1)
24(3)
11(1)
17(2)
221 (10)
14(1)
54(3)
88(3)
23(2)
70(6)
75(4)
235 (8)
49! (14)
"Doer""
Male
90
73
99
166
139
84
153
429
35
69
89
56
131
118
241
492
N=1478b
Female
1(0)
20(2)
82(3)
1(0)
11(2)
6(!)
15(2)
142 (7)
52(2)
90(4)
153(5)
38(2)
43(4)
75 (4)
215(7)
496(11)
"Doer" N = 2762b
Female Total
35
79
94
69 '
101
57
150
384
67
102
154
74
97
110
224
497
3(0)
21(1)
87 (2)
1(0)
17(2)
8(1)
16(1)
179(6)
34(1)
73(2)
12393)
31(1)
56(4)
73(3)
224 (5)
494 (9)
"Doer"
Total
66
77
97
91
i35
74
142
390
57
88
124
67
120
118
232
495
CARB Data
Mean Duration (mins/day) (standard error)*
Microenvironmem
Autoplaces
Restaurant/bar
In- vehicle
In-Vehicle/other
Physical/outdoors
Physical/indoors
Work/study-residence
. Work/study-other
Cooking
Other activities/kitchen
Chores/child
Shop/errand
Other/outdoors
Social/cultural
Leisure-eat/indoors
Sleep/indoors
N = 867b
Male
31(8)
45(4)
. 105(7)
4(1)
25(3)
8(1)
14(3)
213(14)
12(1)
38(3)
66(4)
21(3)
95(9)
47(4)
223(10)
492(17)
"Doer"
Male
142
106
119
79
131
63
126
398
43
65
75
61
153
112
240
499
N = 895"
Female
9(2)
28 (3)
85(4)
3(2)
8(1)
5(1)
M(2)
156(11)
42(2)
60(4)
134(6)
41(3)
44(4)
59 (5)
251(10)
504(15)
"Doer" N=1762b
Female Total
50
86
100
106
86
70
120
383
65
82
140
78
82
114
263
506
20(4)
36(3)
95(4)
3(1)
17(2)
7(1)
13(2)
184(9)
27(1)
49(2)
100(4)
31(2)
69(5)
53(3)
237 (7)
498(12)
"Doer"
Total
108
102
111
94
107
68
131
450
55
74
109
70
117
112
250
501
a Standard error of the mean
b Weighted number
c Doer = Respondents who reported participating in each activity/location spent in microenvironments.
Source: Robinson and Thomas, 1991.
June 2000
9-19
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1
2
*>
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
"* *ป
jj
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
Table 9-6. Mean Time Spent (minutes/day) in Various Microenvironments by Type
of Day for the California and National Surveys
(sample population ages 12 years and older)
Weekday
Microenvironment
1 Autoplaces
2 Restaurant/Bar
' 3 In- Vehicle/Internal Combustion
4 In-Vehicle/Other
5 Physical/Outdoors
6 Physical/Indoors
7 Work/Study-Residence
8 Work/Study-Other
9 Cooking
10 Other Activities/Kitchen
1 1 Chores/Child
12 Shop/Errand ,
13 Other/Outdoors
14 Social/Cultural
15 Leisure-Eat/Indoors
56 Sleep/Indoors
Mean Duration (standard error)1
CARS
(n=I259)e
21(5)
29(3)
.90(5)
3(1)
14(2)
7(!)
14(2)
228 ( 1 1 )
27(2)
51 (3)
99(5)
30(2)
67(6)
42(3)
230 (9)
490(14)
(m ins/day)
NAT
(n=1973)c
3(1)
, 20 (2)
85(2)
1(0)
15(2)
8(1)
16(2)
225 (8)
35(2)
73(3)
124(4)
30(2)
51(4)
62(3)
211(6)
481(10)
Mean Duration for
(mins/day)
CARB
108
83
104
71
106
64
116
401
58
76
108
67
117
99
244
495
"Doer"*
NAT
73
73
95
116
118
68
147
415
57
87
125
63
107
101
218
483
Weekend
Microenvironment
1 Autoplaces
2 Restaurant/Bar
3 In- Vehicle/Internal Combustion
4 In- Vehicle/Other
5 Physical/Outdoors
6 Physical/indoors
7 Worfc/Study-Residence
8 Work/Study-Other
9 Cooking
10 Other Activities/Kitchen
1 1 Chores/Child
12 Shop/Errand
13 Other/Outdoors
14 Social/Cultural
15 Leisure-Eat/Indoors
! 6 Sleep/Indoors
Mean Duration (standard error)*
CARB
-------
1
2
Table 9-7. Mean Time Spent (minutes/day) in Various Microenvironments by Age Groups for the National and California Surveys
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
23
24
25
26
27
28
29
30
31
32
^ ป
34
35
36
37
38
39
40
41
42
National Data
Microenvironment
Autoplaces
Restaurant/bar
In-vehicle/intemal combustion
In-vehicle/other
Physical/outdoors
Physical/indoors
Work/study-residence
Work/study-other
Cooking
Other activities/kitchen
Chores/child
Shop/errands
Other/outdoors
Social/cultural
Leisure-eat/indoors
Sleep/indoors
M i croenvironmem
Auioplaces
Restaurant/bar
In-vehicle/intemal combustion
In-vehicie/other
Physical/outdoors
Physical/indoors
Work/study-residence
Work/study-othcr
Cooking
Other activities/kitchen
Chores/child
Shop/errands
Other/outdoors
Social/cultural
Leisure-eat/indoors
Sleep/indoors
Mean Duration (Standard Error)*
Aae 12-17 years
N=340*
2(1)
9(2)
79(7)
0(0)
32(8)
15(3)'
22(4)
159(14)
11(3)
53(4)
91(7)
26(4)
70(13)
87(10)
237(16)
548(31)
"Doer"'
73
60
88
12
130
87
82
354
40
64
92
68
129
120
242
551
CARS
Age 18-24vears
N=340
7(2)
28(3)
103 (8)
KD
17(4)
8(2)
19(6)
207 (20)
18(2)
42(3)
124 (9)
31(4)
34(4)
100(12)
181 (11)
511(26)
Data
"Doer"
137
70
109
160
no-
76
185
391
39
55
125
65
84
141
189
512
Mean Duration (Standard Error)"
Aae !2-l7vears
N=183"
16(8)
16(4)
78(11)
1(0)
32(7)
20(4)
25 (5)
196 (30)
3d)
31 (4)
72(11)
14(3)-
58(8)
63(14)
260 (27)
557 <44)
"Doer"'
124
44
89
19
110
65
76
339
19
51
77
50
78
109
270
560
Ase 1 8-24 vears
N-250
16(4)
40(8)
111(13)
3(1)
13(3)
5(2)
30(11)
201 (24)
'14 (2)
31 (5)
79(8)
35(7)
80(15)
65(10)
211 (19)
506 (30)
"Doer"
71
98
122
60
88
77
161
344
40
55
85
71
130
110
234
510
' Standard error.
11 All N's are weighted number.
Doer= Respondents who reported participating in each activity/location spent in microenvironmems.
Source: Robinson and Thomas. 1991.
June 2000
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2
**
4
6
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Table 9-8. Mean Time (minutes/day) Children Ages 12 Years and Under Spent in Ten Major
Activity Categories for All Respondents
Activitv Category
Work-related"
Household
Childcare
Goods/Services
Personal Needs and Care'
Education''
Organizational Activities
Entertain/Social
Recreation
Communication/Passive
Leisure
Don't know/Not coded
All Activities'
Mean
Duration
(mins/day)
10
53
<1
21
794
110
4
15
239
192
2
1441
Mean Median Maximum
Duration Duration Duration
% forDoersb for Doer for Doers
Doins (mins/dav) (mins/dav) (mins/dav)
25
86
<1
26
100
35
4
17
92
93
4
39
61
83
81
794
316
111
87
260
205
41
30
40
30
60
770
335
105
60
240
180
15
405
602
290
450
1440
790
435
490
835
898
600
Detailed Activity with
Highest Avg. Minutes
(code)
Eating at work/school/daycare (06)
Travel to household (199)
Other child care (27)
Errands (38)
Night Sleep (45)
School classes (50)
Anend meetings (60)
Visiting with others (75)
Games (87)
TV use (91)
ฐ Includes eating at school or daycare. an activity not grouped under the "education activities" (codes 50-59. 549).
b "Doers" indicate the respondents who repotted participating in each activity category.
* Personal care includes night sleepand daytime naps, eating, travel for personal care.
d Education includes student and other classes, homework, library, travel for education.
' Column total may not sum to 1440 due to rounding error
Source: Wiley eta!.. 1991.
June 2000
9-22
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Table 9-9. Mean Time Children Spent in Ten Major Activity Categories Grouped by Age and Gender
F4
6
8
9
10
11
12
13
14
15
16
12
19
20
r
23
24
25
26
27
Mean Duration (minutes/day)
Activity
Category
Work-related
Household
Chiidcare
Goods/Services
Persona! Needs and Care*
Education11
Organizational Activities
Entertainment/Social
Recreation
Communication/Passive
Leisure
Don't know/Not coded
At! Activities'
Sample Sizes
Unweighted N's
0-2 yrs
4
33
0
20
914
60
1
3
217
187
1
1440
172
3-5 yrs
9
45
0
22
799
67
3
15
311
166
4
1441
151
Boys
6-8 yrs
14
55
0
19
736
171
7
5
236
195
1
1439
145
9-11
yrs
12
65
1
14
690
138
6
34
229
250
1
1440
156
0-11
yrs
10
48
-------
1
"*
4
6
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
Table 9-10. Mean Time Children Ages 12 Years and Under Spent in Ten Major Activity Categories
Grouped by Seasons and Regions
Mean Duration (minutes/day)
Activity Category
Work-related
Household
Childcare
Goods/Services
Personal Needs and
Care"
Education*
Organizational
Activities
Entertainment/Social
Recreation
Communication/Pass
ive Leisure
Don't know/Not
coded .
All Activities"
Sample Sizes
(Unweighted)
Winter
(Jan-Mar)
10
47
<1
19
799
124
3
14
221
203
<]
1442
318
Spring
(Apr-June)
10
58
1
17
774
137
5
12
243
180
2
1439
204
Season
Summer
(July-
Sept)
6
53
-------
1
2
"i
j
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
^24
^^^H) C
~6
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
Table 9-1 1. Mean Time Children Ages 12 Years and Under Spent in Six Major Location Categories for All Respondents (minutes/day)
Location Category
Home
School/Childcare
Friend's/Other's House
Stores. Restaurants.
Shopping Places
In-transit
Other Locations
Don't Know/Not Coded
All Locations
Source: Wiley etal.. 1991.
Mean Mean Median Maximum
Duration % Duration Duration Duration for Detailed Location with Highest
(mins) Doing for Doers for Doers Doers Avg. Time
(mins) (mins) (mins)
1.078 99 1.086 1.110 1.440 Home -bedroom
109 33 330 325 1.260 School or day care facility
80 32 251 144 1.440 Friend's/other's house - bedroom
24 35 69 50 475 Shopping mall
69 83 83 60 I. Ill Traveling in car
79 57 139 105 1.440 Park, playground
<1 1 37 30 90
1.440
Table 9-12. Mean Time Children Spent in Six Location Categories Grouped by Age and Gender
Location Category
Home
School/Childcare
Friend's/Other's House
Stores. Restaurants.
Shopping Places
In-transit
Other Locations
Don't Know/Not Coded
All Locations-
Sample Sizes
(Unweishied)
Mean Duration (minutes/day)
Boys Girls
All All
0-2 yrs ' 3-5 yrs 6-8 yrs 9-llyrs Boys 0-2 yrs 3-5 yrs 6-8 yrs 9-llyrs Girls
1.157 1.134 1.044 1.020 1.094 1.151 1.099 1.021 968 1.061
86 88 144 120 108 59 102 133 149 111
67 73 77 109 80 56 47 125 102 80
21 25 22 15 21 23 35 27 26 28 .
54 62 61 62 59 76 88 53 93 79
54 58 92 114 77 73 68 8! 102 81
<1
-------
2
3
'4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
31
32
33
34
36
37
38
Table 9-13. Mean Time Children Spent in Six Location Categories Grouped by Season and Region
Season
Location Category Winter Spring Summer
(Jan-Mar) (Apr-June) (July-Sept)
Home 1.091 1.042 1.097
School/Childcare 119 141 52
Friend's/Other's House 69 75 108
Stores. Restaurants. 22 21 30
Shopping Places
In-transit ' 75 75 60
Other Locations 63 85 93
Don't Know/Not <1 <1 . <1
Coded
All Locations" 1.439 - 1.439 1.440
Sample Sizes 318 204 -407
(Unweighted N's)
' The column totals mav not sum to 1.440 due to rounding error.
Source: Wiley eta! ..1991.
"
Mean Duration (minutes/day)
Region of California
Fall All So. Bay Rest of
(Oct-Dec) Seasons Coast Area State
L08I 1.078 1,078 1.078 1.078
124 109 113 103 108
69 80 73 86 86
24 24 26 23 23
65 69 71 73 63
76 79 79 76 81
<]
-------
40
35
3V
Number of 25
Child-Days ,ft
15
. 3, 35-4 45 5 -iS S KS .T.-13 8 ai. S ;3>10 SOS 11.1U-111XS13 1iS W >14
Hours Indoors At Home
Figure 9-1. Distribution of the Number of Hours per Day Study Children Spent Indoors at Home
Source: Davis 1995.
June 2000
9-27
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140
"" 120
Number of 10&
Child-pays
60
40
a I
- 0 0.5 1 1.5-2 2JS 3 3.5 4 4JS S 5.5 6 i.& 7 7.5 8--->8
Hours. Indoors Away From Home ,
Figure 9-2. Distribution of the Number of Hours per Day Study Children Spent Indoors Away from Home
Source: Davis 1995.
June 2000
9-28
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Number of
Child-Days
140r
120
too
80
40
20i
fl
Hours Outdoors At Home..
Figure 9-3. Distribution of the Number of Hours per Day Study Children Spent Outdoors at Home
Source: Davis 1995.
June 2000
9-29
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Number of
Child-Bays
200"
150-
10G
soi
0 0.5 1 1.5 2 2.5 3 3.5 4 >4
Hours Outdoors Away From Home
Figure 9-4. Distribution of the Number of Hours per Day Study Children Spent Outdoors Away at Home
Source: Davis 1995.
June 2000
9-30
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1 Table 9-15. Mean Time Spent Indoors and Outdoors Grouped by Age
2
=====^=_==^===s==============
4 Age Groups Time Indoors Time Outdoors
(hours/day) (hours/day)
5 ' 0-2 20 4
6 3-5 18.8 5.2
7 , 6-8 19.7 4.4
8 9-11 19.9 4.1
9
10
11
June 2000 9-31 DRAFT-DO NOT QUOTE OR CITE
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I
2
*t
4
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
Table 9-16. Range of Recommended Defaults for Dermal Exposure Factors
Water Contact
Bathing
Event time
and
frequency*
Exposure
duration
Central
1 0 min/event
1 event/day
350 days/yr
9 years
Upper
15 min/event
1 event/day
350 days/yr
30 years
Soil Contact
Swimming
Central
0.5 hr/event
1 event/day
5 days/yr
9 years
Upper
1 .0 hr/event
1 event/day
1 50 days/yr
30 years
Centra!
40 events/yr
9 years
Upper
350 events/yr
30 years
1 Bathing event time is presented to be representative of baths as well as showers.
Source: U.S. EPA 1992.
Table 9-! 7. Number of Times Taking a Shower at Specified Daily Frequencies by the Number of Respondents
Times/Day
Age (years)
1-4
5-11
12-17
Total N 0
41 *
140 *
270 *
1
30
112
199
2
9
26
65
3 4.
1 *
I *
6 *
5 8 10 11:1-0+ DK
* * * * |
* # * * j
*****
Note: * Signifies missing data: Dk= don't know: N - sample size.
Source: Tsang and Klepeis. 1996
Table 9-18. Time (minutes) Spent Taking a Shower and Spent in the Shower Room
After Taking a Shower by the Number of Respondents
Minutes/Shower
Total N
*_*
0-10
10-20
20-30
30-40
40-50
50-60
60-61
Times (minutes) Spent Taking Showers by the Number of Respondents
Age
i-4
5-11
12-17
41
140
270
1
1
2
13
60
94
14
52
104
10
IS
40
1
3
13
*
2
9
2
4
7
*
S
1
Time (minutes) Spent in ihe Shower Room Immediately After Showering by the Number of Respondents
Age (years)
M
5-11
1*7 |7
41
140
'70
*
3
1
5
9
17
31
110
>06
3
14
29
I
3
10
*
*
3
1
*
2
I
1
NOTE: * - Missing data; DK = don't know: N = sample size: Refused = Refused to answer. A value of 61 for number of minutes signifies tnat
more than 60 minutes were spent.
Source: Tsang and Klepeis. 1996.
June 2000
9-32
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1
2
I
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
S
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
Table 9-19. Time (minutes) Spent Taking a Shower and Spent in the Shower Immediately After Showering
Category
Pereentiles
Total
Populate Group N , 2 5 ,0 25 50 75 91 95 98
99
100
Number of Minutes Spent Taking a Shower (minutes/shower)
Age (years)
Age (years)
Age (years)
1^ 40 5 5 5 5 5 10 17.5 30 50 60
5-11 139 3 4 5 5 10 15 20 30 40 60
12-17 268 5 5 5 7 10 15 25 35 45 60
60
60
60
60
60
61
Number of Minutes Spent in the Shower Room Immediately After Showering (minutes/shower)
Age (years)
Age (years)
Age (years)
1-4 41 0 0 0 0 1 5 10 15 20 45
5-11 137 0 0 0 1 2 5 10 15 20 30
12-17 2619 0001 3 5 10 20 30 40
NOTE: N = doer sample size. Percentiles are the percentage of doers below or equal to a given number of minutes. A value of
number of minutes signifies that more than 60 minutes were spent.
Source: Tsang and Kiepeis.1996
Table 9-20. Total Time Spent Altogether in the Shower or Bathtub and Time Spent
in the Bathroom Immediately After by Number of Respondents
Minutes/Bath
Total *-* 0-0 0-10 10-20 20-30 30-40 40-50 50-60 70-80 80-90 90- 100-
N iOO 110
45
30
52
61 for
110-
120
45
60
61
121-
121
Total Time Spent Altogether in the Shower or Bathtub by the Number of Respondents
Age (years)
1-4
5-11
12-17
198 * ป 35 84 50 2 13 7 1 1 1
265 2 64 107 66 3 7 7 2 2 1 1
239 78 96 46 5 5 8 * ... ป
4
2
1
*
1
*
Time Spent in the Bathroom Immediately Following a Shower or Bath by the Number of Respondents
Age (years)
1-4
5-1 i
12-17
198 2 59 123 12 1 1 *
265 : 33 198 23 3 1 * 1 ' * * *
239 1 17 165 34 16 1 3 2 * * *
*
1
*
*
*
*
Note: * Signifies missing data. DK = respondents answered "don't know". Refused = respondents refused to answer. N = doer sample size in
specified range of number of minutes spent. A value of" 121" for number of minutes signifies that more than 120 minutes %vere spent.
Source: Tsang and Klcpeis. 1996
June 2000
9-33
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1
2
*ป
4
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
,-, ,N|
.?:>
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
Table 9-2 1 . Total Number of Minutes Spent Altogether in the Shower or Bathtub and Spent
in' the Bathroom immediately Following a Shower or Bath
Percemiles
N 1 2 5 10 25 50 75 90 95 98 99
Total Number of Minutes Spent Altogether in the Shower or Bathtub (minutes/bath)
Age(years) 1-4 198 1 5 5 10 15 20 30 45 60 120 120
Age (years) 5-11 263 4 5 5 10 13 20 30 30 60 90 120
Age (years) 12-17 239 4 4 5 7 10 15 30 30 45 60 60
Number of Minutes Spent in the Bathroom Immediately Following a Shower or Bath (minutes/bath)
Age (years) 1-4 196 0 0 0 0 0 2 5 10 15 20 35
Age (years) 5-11 260 0 0 0 0 2 5 10 15 15 30 35
Age (years) 12-17 238 0 0 0 2 5 5 10 20 30 45 45
100
120
121
120
45
120
60
Note: A value of "121" for number cf minutes signifies that more than 120 minutes were spent. N = doer sample size. Percent! les are the
percentage of doers below or equal to a given number of minutes.
Source: Tsang and Klepeis. 1996.
Table 5-22. Range cf Number of Times Washing the Hands at Specified Daily Frequencies by the Number of Respondents
Number of Times/Day
Total N ป-ป 0-0 1-2 3-5 6-9 10-19 20-29 30+
Age (years)
1-4 263 * 15 62 125 35 II 2 3
5-11 348 1 5 61 191 48 , 21 4 2
12-17 326 3 6 46 159 64 30 7 2
Note: * Signifies missing data. N = doer sample size in a specified range or number of minutes spent. DK= respondents answered "don't
know". Refused = respondents refused to answer.
Source: Tsang and Klepeis.1996
Table 9-231 Number of Minutes Spent Working or Being Near Excessive Dust in the Air (minutes/day)
Percemiles
N 1 2 5 10 25 50 75 90 - 95 98 99
Age (vears) 1-4 22 0 0 0 2 5 75 121 121 121 121 121
*~ T.
Age (years) 5-11 50 0 0.5 2 ' 4 15 75 121 121 121 121 121
Age (years) 12-17 52 0 1 2 5 5 20 120 121 121 121 121
DK
10
15
9
100
121
121
121
Note: A valueof "121" fornumberof minutes signifies that more than 120 minutes were spent. N = doer sample size. Percemiles are the
percentage of doers below or equal to a given number ol'minules.
Source: Tsang and Klepeis. 1 996.
June 2000
9-34
DRAFT-DO NOT QUOTE OR CITE
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1
2
Table 9-24. Range of Number of Times per Day a Motor Vehicle was Started in a Garage or Carport
and Started with the Garage Door Closed
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
29
30
31
32
-> *t
jj
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
Total N
1-2
Times/day
3-5
6-9 10+
Dk
Range of the Number of Times an Automobile or Motor Vehicle was Started in a Garage or
Carport at Specified Daily Frequencies by the Number of Respondents
Agซ(years)
1-4
5-11
12-17
111
150
145
68
93
86
39
49
42
2 2
6
12 1
*
2
4
Range of the Number of Times Motor Vehicle Was Started with Garage Door Closed
at Specified Daily Frequencies by the Number of Respondents
Age (yean)
1-4
5-11
12-17 .
III
150
145
99
141
127
8
6
9
2 *
* *
4 1
2
3
4
Note: "'" Signifies missing data: "DK" = respondent answered don't know; Refused - the respondent refused to answer: N = doer sample size.
Source: Tsang and Klepeis. 1996
Table 9-25. Number of Minutes Spent Flavins on Sand. Gravel. Dirt or Grass
Minutes/Day
Total N
-ซ 0-0
0-10
10-20
20-30 30^10
Number of Minutes Spent Playing on Sand or Gravel in a
Age (years)
1-4
5-11
12-17-
216
200
41
13 115
7 96
1 23
15
II
1
9'
12
2
'15
14
4
40-50 50-60
70-80 80-90 90-100
110-120
121
Day by the Number of Respondents
2
*
ซ
3
5
15
2?
3
Number of Minutes Spent Playing in Outdoors on Sand. Grave!. Dirt,
When Fill Dirt Was Present by the Number of Respondents
Age (years)
1-4
5-11
12-17
18-64
>64
3
216
200
41
237
3
* *
11 IIS
15 103
3 19
23 138
1 2
1
14
14
3
19
*
*
10
8
2
9
*
*
13
15
7
13
*
*
1
*
*
ซ
*
*
4
1
ป
1
*
1
18
17
4
20
*
1 5
1 2 1
* 1
or Grass
ซ *
4 *
I
1 *
1 1
* *
7
6
3
*
7
9
2
3
*
16
20
3
,
16
17
*
9
*
Note: "*" = Signifies missing data. "DK" = Don't know. Refused = refused to answer. N = Doer sample size in specified range of number of
minutes spent. A value of " 1 2 1 " for number of minutes signifies that more than 1 20 minutes were spent.
Source: Tsane and Klepeis. 1996.
June 2000
9-35
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1
2
3
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
Table 9-26- Number of Minutes Spent Playing in Sand, Gravel. Dirt or Grass (minutes/day)
Percentiles
Category
Population Group
. N 1
5 10 25 50 75 90 95 98 99 100
Number of Minutes Spent Playing on Sand or Gravel (minutes/day)
Age (years)
Age (years)
Age (years)
1-4
5-11
12-17
203 0 0 0 0 0 0 30 120 121 121 121 121
193 0 0 0 0 0 3 60 121 121 121 121 121
40 0 0 0 0 0 0 45 120 121 121 121 121
Number of Minutes Spent Playing on Sand. Gravel, Dirt, or Grass When Fill Din Was Present (minutes/day)
Age (years)
Age (years)
Age (years)
1-4
5-n
12-17
205 0 0 0 0 0 0 30 120 121 121 121 121
185 0 0 0 0 0 0 30 120 121 121 121 121
38 0 0 0 0 0 0.5 "30 60 120 120 120 120
NOTE: Avalueof"121"fornumberofminutessignifiesthatmorethan 120 minutes were spent. N = doer sample size. Percentiles are the
percentage of doers below or equal to a given number of minutes.
Source; Tsangand Klepeis.1996
Table 9-27. Range of Number.of Minutes Spent Playing on Grass in a Day by the Number of Respondents
Minutes/Day
Total
N
*-* 0-0 0-10 10-20 20-30 30-40 40-50 50-60 60-70 70-80 80-90 90- 100- 110- 121-
100 110 120 121
Age (years)
1-4
5-11
12-17
216 10 24
200 15 24
4! 2 5
19
10
1
21
10
25
19
8
35
38
8
18 49
20 49
8 5
NOTE: "*" signifies missing data. A value of "121" for number of minutes signifies that more than 120 minutes were spent. N = doer sample
size. Percentiles are the percentage of doers below or equal to a given number of minutes. Refused - respondent refused to answer.
Source: Tsangand Klepeis.1996.
Table 9-28. Number of Minutes Spent Playing on Grass (minutes/day)
Percentiles
Cateaorv
Population Group
5 10 25 50 75 90 95 98 99 100
Age (years)
Age (years)
Aae (vears)
1-4
5-11
12-17
206
185
39
0
0
0
0
0
0
0
0
0
0
0
0
15
30
30
60
60
60
120 121
121 121
120 121
12! 121
121 121
12! 121
121 121
121 121
12! 121
NOTE: A value of "121" fornumberof minutes signifies that more than 120 minutes were spent. N = doer sample size. Percentiles are the
percentage of doers below or equal to a given number of minutes.
Source: Tsang and Klepeis.1996
June 2000
9-36
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2
!3
4
6
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
28
29'
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
Table 9-29. Number of Times Swimming in a Month in Freshwater Swimming Pool by the Number of Respondents
Times/Month
Total N 12345
Age (years)
1-4 63 11 14 7 3 3
5-11 100 16 15 7 9 6
12-17 84 21 13 7 4 8
6 7 8 9 10 11 12 13 14 15 16
4 1 3 1 4*2'l 12*
424*7*5*" 11 2
42318*1**2*
Times/Month
18 20 23 24 25 26
Age (years)
5-11 * 3 1 2
12-17 1 4 ซ * * 1
28 29 30 31 32 40 42 45 50 60 DK
Note: * Signifies missing data: "DK" = respondent answered don't know; N= sample size: Refused - respondent refused to answer.
Source: Tsana And Klepeis. 1996
Table 9-30. Number of Minutes Spent Swimming in a Month in Freshwater Swimming Pool (minutes/month)
N 1
Age (years) 1-4 60 3
Age (years) 5-11 95 2
Age (years) 12-17 83 4
Note: A Value of 181 for number of minutes signifies that more than
percentage of doers below or equal to a given number of minutes.
Source: Tsang and Klepeis. 1 996.
Table 9-3 1 . Range of the Average Amount of Time Actually
Percentiles
2 5 10 25 50 75 90 95 98 99 100
3 7.5 15 20 42.5 120 ISO 181 181 18! !8I
3 20 30 45 60 120 180 18! 181 181 181
5 15 20 40 -60 120 180 181 181 181 181
180 minutes were spent. N = doer sample size. Percentiles are the
Spent in the Water by Swimmers by the Number of Respondents
Minutes/Month
Total
N ป- 0-10 10-20 20-30 30-40
Age (years)
1-4 63 ' 3 5 12 12 1
5-1 1 100 5 3 2 12 5
12-17 84 1 3 7 10 2
90- 110- 150- 180- 181-
40-50 50-60 60-70 70-80 80-90 100 i20 150 180 181
4 8 * * 2 7 1 35
4 25 * * 7 * 16 2 1! 8
6 15 * 1 8 1 14 4 6 6
Note: * Signifies missing data. DK = respondents answered don't know. Ref= respondents refused to answer. N * doer sample size in
specified range of number of minutes spent. Values of 120. 150.and 180 for number of minutes signify that 2 hours. 2.5 hours, and 3 hours.
respectively, were spent.
Source: Tsang and Klepeis. 1996.
June 2000
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1
2
Table 9-32. Statistics for 24-Hour Cumulative Number of Minutes Spent Playing indoors and Outdoors
4
5
6
7
$
9
10
11
12
13
14
15
16
17
20
2
23
24
25
26
27
28
Percemiles
Category
Population Group
N Mean Stdev Stderr Min Max 5 25 50 75 90 95 98 99
Statistics for 24-Hour Cumulative Number of Minutes Spent in Indoor Playing
Age (years)
Age (years)
Age (years)
1-4
5-11
12-17
II
11
4
130
93.6
82.5
80.2
64.3
45
24.2
19.4
22.5
15
30
30
270 15
195 30
120 30
60 115
30 60
45 90
180
175
120
255 270
180 195
120 120
270 270
195 195
120 120
Statistics for 24-Hour Cumulative Number of Minutes Spent in Outdoor Flavins
34
35
36
37
38
39
40
41
42
43
Age (years)
Age (years)
Age (years)
5-11
12-17
4 83.25 89.66 44.83 15 210 15 20 54 146.5
9 148.333 144.265 48.088 5 360 5 55 60 280
I 15 * * 15 15 15 15 15 15
210 210 210 210
360 360 360 360
15 15 15 15
Note: A "*" Signifies missing data. "DK" = The respondent replied "don't know". N = doer sample size. Mean = Mean 24-hour cumulative
number of minutes for doers. Stdev = standard deviation. Stderr = standard error. Min-minimum number of minutes. Max-maximum
number of minutes. Percemiles are the percentage of doers below or equal to a given number of minutes.
Source: Tsang and Klepeis. 1996.
Table 9-33. Statistics for 24-Hour Cumulative Number of Minutes Spent Sleeptng/Nappi
-------
1
2
M
5
6
7
8
9
10
11
12
13
14
Table 9-35. Statistics for 24-Hour Cumulative Number of Minutes Spent in Active Sports
and for Time Spent in Sports/Exercise
.Category
Population' Croup N
Mean
Stdev
Stderr
Min Max
5
25
Percemties
50 75 90 95
98
99
Statistics for 24-Hour Cumulative Number of Minutes Spent in Active Sports
Age (years)
Age (years)
Age (years)
M . 105
5-1 1 247
12-17 215
115.848
148.87
137.46
98.855
126.627
124.516
9.6472
8.0571
8.4919
10 630
2 975
5 1065
30
20
15
45
60
60
90 159 250 330
120 18S 320 390
110 180 265 375
345
510
470
390
558
520
Statistics for 24-Hour Cumulative Number of Minutes Spent in Sports/Exercise (a)
Age (years)
Age (years)
Age (years)
1-4 114
5-11 262
12-17 237
118.982
153.496
134.717
109.17
130.58
122.228
10.2247
8.0673
7.9396
10 670
2 975
5 1065
25
20
15
45
60
60
90 159 250 330
120 200 330 415
110 179 265 360
390
525
470
630
580
520
a Includes active sports, exercise, hobbies.
Note: "DK" = The respondent replied "don't know'. Refused - Refused data. N = doer sample size. Mean * Mean 24-hour cumulative number of minutes for doers.
Stdev ซ standard deviation. Slderr - standard error. Min = minimum number of minutes. Max = maximum number of minutes. Percentiles are the percentage of
21
22
23
24
25
26
I7
is
29
30
31
32
Source: Tsang and Klepeis. 1996.
Table 9-36. Statistics for 24-Hour Cumulative Number of Minutes Spent in Outdoor Recreation and Spent Walking
Pcrcentiles
Category Population Group
N Mean Stdev
Stderr Min
Mn 5
25
50
75
90
95
98
99
Statistics for 24-Hour Cumulative Number of Minutes Spent in Outdoor Recreation
Age (years) 1-4
Age (years) 5-11
Age (years) 12-17
13 166.54 177.06
21 206.14 156.17
27 155.07 128.28
49.109 15
34.078 30
24.687 5
630 15
585 60
465 5
30
90
60
130
165
135
ISO
245
225
370
360
420
630
574
420
630
585
465
630
585
465
J J> Statistics for 24-Hour Cumulative Number of Minutes Spent Walking
34
35 *
36
37
1
41
42
Age (years) 1-4
Age (years) 5-11
Age (years) 12-17
Note: "DK" = The respondent replied "don't know".
Stdev = standard deviation. Stderr = standard error.
doers below or equal to a given number of minutes.
Source: Tsang and Klepeis. !996.
58 24.3276 26.3268
155 18.2129 21.0263
223 25.8341 32.3753
3.4569 1'
1 .6889 1
2.168 1
160 2
170 1
190 2
10
5
6
15
10
15
35
25
30
60
40
60
60
60
100
70
65
135
160
100
151
Refused - Refused data. N = doer sample size. Mean = Mean 24-hour cumulative number of minutes for doers.
Min minimum number of minutes. Max = maximum number of minutes. Percentiles are the percentage of
June 2000
9-39
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1
2
3
4
5
6
7
8
9
Group Name
Age (years)
Age (years)
Age (years)
Table 9-37.
Group Code
1-4
5-11
12-17
Statistics for 24-Hour Cumulative Number of Minutes Spent in Bathing (a)
N Mean Stdev Stderr Min Max 5 25 50
330 29.9727 19.4226 1.0692 1 170 10 15 30
438 25.7511 35.3164 1.6875 1 690 5 15 20
444 23.1216 18.7078 0.8878 ! 210 5 10 18
Percentiles
75 90 95
31 54.5 60
30 45 60
30 45 60
98
85
60
65
99
90
75
90
U a includes baby and child care, personal care services, washing and personal hygiene (bathing, showering, etc.)
?
4
Note: "DK" =
The respondent replied "don't know".
Refused - Refused data. N - doer sample size. Mean - Mean 24-hour cumulative number of minutes for doers.
Stdev = standard deviation. Stderr - standard error. Min = minimum number of minutes. Max = maximum number of minutes.
Percent] ies are the percentage of
doers below or equal to a given number of minutes.'
O Source: Tsang and Kiepeis. 1996.
[7
18
19
20
11
12
*-*
14
15
16
11
;g
'X
>0
ii
>2
* "V
> -\
'J
A
>5
>6
>7
>8
>9
K)
rl
Category
Age (years)
Age (years)
Age (years)
Note: "DK" ซ
Table 9-38.
Population Group
1-4
5-M
12-17
The respondent replied "don't know".
S:dev - standard deviation. Stderr = standard error
Statistics for 24-Hour Cumulative Number of Minutes Eating or Drinking
N Mean Stdev Stderr Min Max 5 25 50
492 93.4837 52.8671 2.?834 2 345 20 60 90
680 68.5412 38.9518 1.4937 5 255 15 40 63
535 55.8587 34.990J 1.5085 2 210 10 30 50
Percentiles
75 90 95
120 160 190
90 120 142.5
75 105 125
98
225
165
150
99
270
195
170
Refused = Refused data. N - doer sample size. Mean = Mean 24-hour cumulative number of minutes for doers.
Min - minimum number of minutes. Max ** maximum number of minutes.
Percentiles are the percentage of
doers below or equal to a given number of minutes.
Source: Tsang arid Kiepeis, 1996.
Table 9-39. Statistics for 24-Hour Cumulative Number of Minutes Spent Indoors at School and Indoors at 3 Restaurant
Percemiles
Category
Population Group
N Mean Sldev Stderr Min Max 5 25 50
75 90 95
98
99
Statistics for 24-Hour Cumulative Number of Minutes Spent Indoors at School
Age (years)
Age (years)
Age (years)
1-4
5-H
12-17
43 288.465 217.621 33.187 5 665 10 60 269
302 396.308 109.216 6.285 5 665 170 365 403
287 402.551 125.512 7.409 15 855 120 383 420
500 580 595
445 535 565
450 500 565
665
625
710
665
640
778
-i Statistics for 24-Hour Cumulative Number of Minutes Spent Indoors at a Restaurant
13
W
r6
7
8
9
0
1
Age (years)
Age (years)
Age (years)
Note: "DK" -
1-4
5-11
12-17
The respondent replied "don't know".
Stdev - standard deviation . Stderr = standard error
61 62.705 47.701 6.1075 4 330 10 35 55
84 56.69 38.144 4.1618 5 180 10 30 45
122 69.836 78.361 7.0945 2 455 10 30 45
85 115 120
85 120 120
65 165 250
130
140
?25
330
180
360
Refused = Refused data. N = doer sample size. Mean - Mean 24-hour cumulative number of minutes for (foers.
Min = minimum number of minutes. Max = maximum number of minutes.
Percentiles are the percemace of
doers below or equal to a given number of minutes.
Source: Tsang and Kiepcis. 1996.
June 2000
9-40
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1
0
>4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
1
27
28
Table 9-40. Statistics for 24-Hour Cumulative Number of Minutes Spent Outdoors on School Grounds/Playground.
at a Park/Golf Course, and at a Pool/River/Lake
Percentilcs
Category Population Croup
N' Mean
Stdev Stderr
Min
Max 5
25 50
75
90
95
98
99
Statistics for 24-Hour Cumulative Number of Minutes Spent Outdoors on School Grounds/Playground
Age (years) 1-4
Age (years) 5-11
Age (years) 12-17
Age (years) 18-64
Age (years) > 64
9 85
64 88.016
76 78.658
101 119.812
7 65
61.084 20,36
95.638 11.96
88.179 10.12
127.563 12.69
47.258 17.86
10
$
3
1
5
175 10
625 10
570 5
690 5
150 5
30 65
30 60
25 55
30 85
30 60
140
120
105
165
95
175
170
165
240
150
175
220
225
360
150
175
315
370
540
150
175
625
570
555
ISO
Statistics for 24-Hour Cumulative Number of Minutes Spent Outdoors at a Park/Golf Course
Age (years) 1-4
Age (years) 5-1)
Age (years) 12-17
21 149.857
54 207.556
52 238.462
176.25 38.4609
IS4.496 25.1068
242.198 33.5869
21
25
15
755 25
665 35
1065 15
50 85
70 125
150
275
60 147.5 337.5
360
555
590
425
635
840
755
660
915
755
665
1065
Statistics for 24-Hour Cumulative Number of Minutes Spent Outdoors at a Pool/River/Lake
Age (years) 1-4
Age (years) 5- It
Age(vears) 12-17
Note: ' DK" = The respondent replied "don't know".
Stdev = standard deviation. Siderr * standard error.
doers below or equal to a given number of minutes.
Source: Tsang and Klepeis. 1996.
14 250.571
29 175.448
22 128.318
177.508 47.441
117.875 21.889
94.389 20.124
90
25
40
630 90
390 30
420 58
130 167.5
60 145
60 82.5
370
293
2!0
560
365
225
630
375
235
630
390
420
630
390
420
Refused = Refused data. N = doer sample size. Mean - Mean 24-hour cumulative number cf minutes for doers.
Min -minimum number of minutes. Max = maximu.Ti number of minutes. Percentiies are the percentage of
June 2000
9-41
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1
2
i
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
Table 9-41. Statistics for 24-Hour Cumulative Number of Minutes Spent at Home in the Kitchen
Bathroom. Bedroom, and in a Residence (All Rooms)
Percemiles
Category
Population Croup N* Mean Sldev
Stderr
Min
Max
5 25
50
75
90
95
98 99
Statistics for 24-Hour Cumulative Number of Minutes Spent at Home in the Kitchen
Age (years)
Age (years)
Age (years)
M
5-11
12-17
335 73.719 54.382
477 60.46S 52.988
396 55.02 58.1 1 1
2.9712
2.4262
2.9202
5 .
1
1
392
690
450
15 30
10 30
5 15
60
50
36
100
75
65
140
120
125
180
150
155
225 240
180 235
240 340
Statistics for 24-Hour Cumulative Number of Minutes Spent in the Bathroom
Age (years)
Age (years)
Age (years)
M
5-11
12-17
328 35.939 46.499
490 30.9673 38.609
445 29.0517 32.934
2.5675
1.7442
1.5612
t
1
1
600
535
547
10 15
5 15
5 15
30
27
20
40
35
35
60
52.5
60
75
60
65
125 270
100 200
90 100
Statistics for 24-Hour Cumulative Number of Minutes Spent at Home in the Bedroom
Age (years)
Age (years)
Age (years)
1-4
5-11
12-17
488 741.988 167.051
689 669.144 162.888
577 636.189 210.883
7.562
6.2055
8.7792
30
35
15
1440
1440
1375
489 635
435 600
165 542
740
665
645
840
740
750
930
840
875
990
915
970
1095 1200
1065 1 140
1040 1210
Statistics for 24-Hour Cumulative Number of Minutes Spent Indoors in a Residence (all rooms)
Age (years)
Age (years)
Age' (years)
1-4
5-11
12-17
498 1211.64 218.745
700 1005.13 222.335
588 969.5 241.776
9.8022
8.4035
9.9707
270
190
95
1440
1440
1440
795 1065
686 845
585 811.5
1260
975
950
1410
1165
1155
1440
1334
1310
1440
1412.5
1405
1440 1440
1440 1440
1440 1440
Note: "DK~ = The respondent replied "don't know". Refused = Refused data. N = doer sample size. Mean = Mean 24-hour cumulative nu.nber of minutes for doers.
Stdev = standard deviation. Stderr = standard error. Min-minimum number of minutes. Max = maximum number of minutes. Percentiles are the percentage of
doers below or equal to a given number of minutes.
Source: Tsanj! and KJepeis. 1996.
June 2000
9-42
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Table 9-42. Statistics for 34-Hour Cumulative Number of Minutes Spent Traveling Inside a Vehicle
Percemiles
Category Population Group N Mean Stdev Stderr Min Max 5 25 50 75 90 95 98 99
Age (years)
Age (years)
Age (years)
1-4
5-11
12-17
335
571
500
ฃ8.116
71.033
81.53
75.531
77.62
79.8
4.1267
3.24S3
3.5687
1 955
1 900
1 790
10 30
10 25
10 30
47
51
60
85
90
100
150 200
140 171
165.5 232.5
245 270
275 360
345 405
Note: "DK" = The respondent replied "don't know". Refused - Refused data. N = doer sample size. Mean ซ Mean 24-hour cumulative number of minutes for doers.
Stdev standard deviation. Stderr = standard error. Min = minimum number of minults. Max = maximum number of minutes. Percemiles are the percentage of
doers below or equal to a given number of minutes.
Source: Tsane and Klepeis. 1996.
Table 9-4?. Statistics for 24-Hour Cumulative Number of Minutes Spent Outdoors (outside the residence) and Outdoors
Other Than Near a Residence or Vehicle. Such as Parks. Golf Courses, or Farms
s========!====s=======^^
Percentilcs
Group Name Group Code N Mean Stdev Stderr Min Max 5 25 50 75 90 95 98 99
Statistics for 24-Hour Cumulative Number of Minutes Spent Outdoors (outside the residence)
Age (years) 1-4 201 195.652 163.732 11.5488 3 715 30 75 135 270 430 535 625 699
A?e (years) 5-11 353 IS7.564 158.575 8.4401 4 1250 20 80 150 265 365 479 600 720
Age(years) 12-17 219 135.26 137.031 9.2597 I 720 5 35 100 190 SCO 452 545 610
Statistics for 24-Hour Cumulative Number of Minutes Spent Outdoors Other Than
Near a Residence or Vehicle Such as Parks. Golf Courses, or Farms
Age (years)
Age (years J
Age (years)
J-ป
5-11
12-17
54
159
175
164.648 177.34
171.34 177.947
156.903 174.411
24.133
14.112
13.184
1 980
5 1210
5 !065
10 60
15 55
10 45
120
115
100
175
221
210
.70
405
385
560
574
570
630 980
660 725
735 915
Note: "DK" = The respondent replied "don't know". Refused - Refused data. N ~ doer sample size. Mean - Mean 24-hour cumulative number of minutes for doers.
Sldev = standard deviation. Stderr = standard error. Min = minimum number of minutes. Max = maximum number of minutes. Pcrcemiles are the percentage of
doers below or equal to a given number of minutes.
Source: Tsang and Klepeis. 1996.
Table 9-44. Statistics for 24-Hour Cumulative Number of Minutes Spent in Malls. Grocer.- Stores, or Other Stores
Pereenti les
Group Name Group Code N Mean Stdev Stderr Min Max 5 25 50 75 90 95 98 99
Age (years)
Age (years)
Age (years)
1-4
5-11
12-17
110
129
140
90.036
77.674
88.714
77.887
6S.035
101.361
7.4263
5.9901
8.5666
5 420
3 320
1 530
!0 40
5 50
5 20
65 105
60 110
45 123.5
210
ISO
222.5
250
225
317.5
359 360
255 2SO
384 413
Note: "DK" = The respondent replied "don't know". Refused = Refused data. N = doer sample size. Mean ซ= Mean 24-hour cumulative number of minutes for doers.
Stdev = standard deviation. Stderr = standard error. Min = minimum number of minutes. Max - maximum number of minutes. Percemiles are the percentage of
doers below or equal to a given number of minutes.
Source: Tsang and Klepeis. 1996.
June 2000 9-43 DRAFT-DO NOT QUOTE OR CITE
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_ (N
c 5 S ?
ซป g 2
ซ** i>* i>- _
r. -ซgr f^
O v.
2 S
_
O
I
= ^ ^ r^
rg ^r
i/: m P^ r^
3 sg * -2
T T r4
w.
^ < < <
-------
1
2
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
M
29
30
31
32
I -ป
34
35
36
37
38
Table 9-46. Range of Time (minutes) Spent Smoking Based on the Number of Respondents
*.*
Age (years)
1-4 499 344
5-1 1 703 479
12-17 589 333
660- 720-
720 780
Age (years)
1-4 35
5-11 72
12-17 7 3
0-60 60- 120-
120 180
29 23 14
40 38 32
75 31 30
780- 840- 900-
840 900 960
632
5 2 *
5 3 1
Number of Minutes
180- 240- 300- 360- 420-
240 300 360 420 480
8 10 7 8 .7
23 10 9 6 12
20 22 15 13 7
Number of Minutes
960- 1020- 1080- 1140- 1200-
1020 1080 1140 1200 1260
3 2-2 I
15223
1 * ป * 2
480- 540- 600-
540 600 660
875
6 11 6 .
13 5 3
1260- 1320- 1380-
1320 1380 1440
1 * 1
* * 2
* *
Note: * = Missing Data: DK =Don't know: N = Number of Respondents: Refused = Respondent Refused to Answer.
Source: Tsang And KJepeis. 1996.
Table 9-47. Number of Minutes Spent Smoking (minutes/day)
Category Population Group
Age (years) ! -4
Age (years) 5-11
Age (years) 12-17
N I 2 5
499 0 0 0
703 0 0 0
589 0 0 0
Percent! les
10 25 50 75 90 95
0 0 0 75 455 735
0 0 0 82 370 625
0 0 0 130 377 542
98 99 100
975 1095 1440
975 1140 1440
810 864 1260
Note: N = Doer Sample Size: Hercentiles are the Percentage of Doers beiow or Equal to a Given Number of Minutes.
Source: Tsang and Klepeis. 1996.
June 2000
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1
2
*>
6
7
$
9
10
11
12
13
14
15
16
17
Table 9-48. Gender and Age Groups
Gender-Age Group
Adolescents
Children"
Subgroup
Males
Females
Young mates
Young females
Old males
Old females
n
98
85
145
124
156
160
Age Range
12-17 years
12-1 7 years
6-8 years
6-8 years
9-1 1 years
9-11 vears
a Children under the age of 6 are excluded for the present study (too few responses in CARS study).
Source: Funk et aJ.. 1998.
June 2000
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1
2
ป
4
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
Table 9-49. Assignment of At-Home Activities to Ventilation Levels for Children
Low
Watching child care
Night sleep
Watch Personal care
Homework
Radio use
TV use
Records/tapes
Reading books
Reading magazines
Reading newspapers
Letters/writing
Other leisure
Homework/watch TV
Reading/TV
Reading/listen music
Paperwork
Moderate
Outdoor cleaning
Food Preparation
Metal clean-up
Cleaning house
Clothes care
Car/boat repair
Home repair
Plant care
Other household
Pet care
Baby care
Child care
Helping/teaching
Talking/reading
Indoor playing
Oudoor playing
Medical child care
Washing, hygiene
Medical care
Help and care
Meals at home
Dressing
Visiting at home
Hobbies
Domestic crafts
Art
Music/dance/drama
Indoor dance
Conservations
Painting room/home
Building fire
Washing/dressing
Outdoor play
Playing/eating
Playing/talking
Playing/watch TV
TV/eating
TV/something else
Reading book/eating
Read magazine/eat
Read newspaper/eat
22
23
24
Source: Funk et a!.. 1998.
June 2000
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1
2
4
6
7
8
9
10
11
12
13
15
16
17
18
19
20
21
9")
2.2.
23
24
25
26
?7
28
29
30
31
32
3 J
34
35
36
37
38
39
40
41
42
43
Table 9-50. Aggregate Time Spent (minutes/day) At-Home in Activity Groups
by Adolescents and Children"
Adolescents Children
. . _
Mean SD Mean SD
Low 789 230 823 153
Moderate 197 131 241" 136
High 1 1J 3 17
HiglWiM,,sc 43 72 58 47
a Time spent engaging in all activities embodied by Ve category (minutes/day).
b Significantly differ from adolescents (p <0.05).
c Represents time spent at-home by individuals participating in high ventilation levels.
Source: Funk et aL 1 998.
Table 9-5 1 . Comparison of Mean Time (minutes/day) Spent At-Home by Gender3 (Adolescents)
Male Female '
Mean SD Mean SD
Low 775 206 804 253
Moderate 181 126 241 134
High 2 16 0 0
Source: Funk et a!.-. 1998.
Table 9-52. Comparison of Mean Time (minutes/day) Spent At-Home by Gender and Age for Children'
Activity Males Females
Group
6-8 Years 9-1 1 Years 6-8 Years 9-1 1 Years
Mean SD Mean SD Mean SD Mean
Low 806 134 860 157 828 155 803
Moderate 259 135 198 111 256 141 247
High 3 17 7 27 1 92
Hi2hMrtici[OT:!c 77 59 70 54 68 II 30
a Time spent engaging in ail activities embodied by Ve category (minutes/day)
b Participants in high Ve activities
Source: Funk et aL. 1998.
SD
162
146
10
23
June 2000
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2
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*4
5
6
1
8
9
10
11
12
13
14
15
16
11
18
fc.
*>
20
21
22
23
24
25
26
21
28
29
30
31
32
Table 9-53. Number of Person-Days/Individuals* for Children in CHAD* Database
Age Group
Oyear
0-6 months
6-12 months
1 year
12- 18 months
18-24 months
2 years
3 years
4 years
5 years
6 years
7 years
8 years
9 years
1 0 years
1 1 years
Total
' CHAD - Consolidated
All Studies
223/199
259/238
317/264
278/242
259/232
254/227
237/199
243/213
259/226
229/195
224/199
227/206
3009/2640
Human Activitv
California"
104
50
54
97
57
40
112
113
91
98
81
85
103
90
105
121
1200
Cincinnati'
36/12
15/5
21/7
31/11
81/28
54/18
41/14
f
40/14
57/19
45/15
49/17
51/17
38/13
32/11
556/187
NHAPS-Air NHAPS-Water
39
64
57
51
64
52
59
57
51
42
39
44
619
.44
67
67
60
63
64
40
56
55
46
42
30
634
Database is available on U.S. EPA Intranet.
b The California study referred to in this table is the Wiley 1991 study.
c The Cincinnati study referred to in this table is the Johnson
The number of person-
days of data are
1989 study.
the same as the number of individuals for all
Since up to three days of activity pattern data were obtained
studies except
from each participant in this studv. the
for the Cincinnati study.
number of person-days of
data is approximately three times the number of individuals.
Source: Hubal et al.. 2000.
June 2000
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5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Table 9-54. Number of Hours Per Day Children Spend in Various Microenvironments by
Average ฑ Std. Dev. (Percent of Children Reporting >0 Hours in Microenvironment)
Age (years)
0
I
2
3
4
5
6
T
8
9
10
11
Source: Hubal et al.
indoors at Home
19.6 ฑ4.3 (99%)
19.5 ฑ4. 1 (99)
17.8 = 4.3(100)
18.0 ฑ4.2 (100)
1 7.3 ฑ4.3 (100)
16.3 ฑ4.0 (99)
16.0 = 4.2(98)
15.5ฑ3.9(99)
1 5.6 ฑ4.1 (99)
15.2 ฑ4.3 (99)
16.0 ฑ4.4 (96)
14.9 ฑ4.6 (98)
.. 2000.
Outdoors at Home
I.4ฑ 1.5(20%)
1.6 ฑ 1.3(35)
2.0 ฑ1.7 (46)
2.1 ฑ1.8 (48)
2.4 ฑ 1.8(42)
2.5 ฑ2.1 (52)
2-6 ฑ 2.2 (48)
2.6 ฑ2.0 (48)
2.1 ฑ2.5(44)
2.3 ฑ 2.8 (49)
1.7ฑ 1.9(40)
1.9 ฑ2.3 (45)
Indoors at School
3.5 ฑ 3.7 (2%)
3.4 ฑ3.8 (5)
6.2 ฑ 3.3 (9)
5.7 ฑ2.8 (14)
4.9 ฑ3.2 (16)
5.4 ฑ 2.5 (39)
5.8 = 2.2(34)
6.3 ฑ 1.3(40)
6.2 ฑ 1.1 (41)
6.0 ฑ 1.5(39)
5.9 ฑ 1.5(39)
5.9ฑ1.5(41)
Outdoors at Park
1.6 ฑ1.5 (9%)
1.9 ฑ2.7 (10)
2.0 ฑ1.7 (17)
1.5 ฑ0.9 (17)
2.3 ฑ 1.9(20)
1.6 ฑ1.5 (28)
2.1 ฑ2.4 (32)
1.5 ฑ1.0 (28)
2.2 ฑ 2.4 (37)
1,7=1.5(34)
22 ฑ 2.3 (40)
2.0=1.7(44)
Age
In Vehicle
1.2 ฑ1.0 (65%)
1.1 ฑ0.9 (66)
1.2 ฑ1.5 (76)
1.4ฑ 1.9(73)
1.1 ฑ0.8 (78)
1.3 ฑ1.8 (80)
1.1=0.8(79)
1.1ฑ 1.1 (77)
1.3 ฑ2.1 (82)
1. 2 ฑ1.2 (76)
1.1 ฑ1.1 (82)
1.6ฑ 1.9(74)
June 2000
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3
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5
6
7
8
9
10
11
12
13
14
15
16
17
18
'19
20
21
22
23
24
Table 9-55. Average Number of Hours Per Day Children Spend Doing Various
Macroactivities While Indoors at Home by Age
(Percent of Children Reporting >0 Hours for Microenvironment/macroactivity )
Age
(year)
0
1
2
3
4
5
6
7
8
9
10
11
Source:
Eat
1.9(96%)
1-5(97)
1-3(92)
5-2(95)
1-1 (93)
1.1 (95)
1.1 (94)
1.0(93)
0.9(91)
0.9 (90)
1.0(86)
0.9 (89)
Sleep or Nap
12.6 (99%)
12.1 (99)
11.5(100)
11.3(99)
10.9(100)
10.5 (98)
10.4 (98)
9.9 (99)
10.0 (96)
9.7 (96)
9.6 (94)
' 9.3(94)
Shower or
Bathe
0.4 (44%)
0.5 (56)
0-5 (53)
0.4 (53)
0-5 (52)
0.5 (54)
0.4 (49)
0.4 (56)
0.4(51)
0.5 (43)
0.4 (43)
0.4 (45)
Play Games
4.3 (29%)
3.9 (68)
2-5 (59)
2.6 (59)
2.6 (54)
2.0 (49)
1.9(35)
2.1 (38)
2.0 (35)
1.7(28)
1.7(38)
1.9(27)
Watch TV or
Listen to Radio
1.1 (9%)
1-8(41)
2.1 (69)
2.6(81)
2.5 (82)
2.3 (85)
2.3 (82)
2.5 (84)
2.7 (83)
3.1 (83)
3.5 (79)
3.1 (85)
Read. Write.
Homework
0.4 (4%)
0.6(19)
0.6 (27)
0.8 (27)
0.7(31)
0.8(31)
0.9 (38)
0.9 (40)
1.0(45)
1.0(44)
1.5(47)
'1.1(47)
Think. Relax.
Passive
3.3 (62%)
2.3 (20)
1.4(18)
1.0(19)
1.1(17)
1.2(19) .
1-1 (14)
0.6(10)
0.7 (7)
0.9(17)
0.6(10)
0.6(10)
Hubal et al.. 2000.
June 2000
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Table 9-56. Confidence in Activity Patterns Recommendations
Considerations
Rationale
Rating
8
9
10
II
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
TIME SPENT INDOORS VS. OUTDOORS
Study Elements
Level of peer review
Accessibility
* Reproducibility
Focus on factor of
interest
Data pertinent to US
Primary data
Currency
* Adequacy of data
collection period
Validity of approach
Study size
Representativeness of
the population
Characterization of
variability
Lack of bias in study
design (high rating is
desirable)
Measurement error
Other Elements
Number of studies
Agreement between
researchers
Overall Rating
The study received high level of peer review. High
The study is widely available to the public. High
The reproducibility of these studies is left to question. Evidence has Medium
shown that activities have tended to shift over the past decade since the
study was published, due to economic conditions and technological
developments, etc. Thus, it is assumed there would be differences in
reproducing these results. However, if data were reanalyzed in the same
manner the results are expected to be the same.
The study focused on general activity patterns. High
The study focused on the U.S. population. High
Data were collected via questionnaires and interviews. High
The studies were published in 1985 (data were collected 1981 -1982). Medium
Households were sampled 4 times during 3 month intervals from High
February to December, 1981.
A 24 hour recall time diary method was used to collect data. High"
The sample population was 922 children between the ages of 3-17 years High
old.
The study focused on activities of children. High
Variability was characterized by age, gender, and day of the week; Medium
location of activities and various age categories for children.
Biases noted were sampled during time when children were in school Medium
(activities during vacation time are not represented); activities in the
1980's may be different than they are now;
Measurement or recording error may occur since the diaries were based Medium
on recall (in most cases a 24 hour recall).
Two High
Difficult to compare due to varying categories of activities and the unique Not
age distributions found withjn each study. Ranked
Medium
June 2000
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3
4
5
6
7
8
9
10
11
12
13
14
Table 9-56. Confidence in Activity Patterns Recommendations (cont'd)
Considerations
Rationale
Rating
TIME SPENT SHOWERING
Study Elements
Level of peer review
* Accessibility
Reproducibility
Focus on factor of
interest
Data pertinent to US
Primary data
Currency
* Adequacy of data
collection period
The study received high level of peer review.
Currently, raw data are available to only EPA. It is not known when data
will be publicly available.
Results are reproducible.
The study focused specifically focused on time spent showering.
The study focused on the U.S. general population.
The study was based on primary data.
The study was published in 1996.
The data were collected between October 1992 and September 1994.
High
Low
High
High
High
High
High
High
15
Validity of approach
The study used a valid methodology and approach which, in addition to
24-hour diaries, collected information on temporal conditions and
demographic data such as geographic location and socioeconomic status
for various U.S. subgroups.
High
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Study size
Representativeness of
the population
Characterization of
variability
* Lack of bias in study
design (high rating is
desirable)
Measurement error
Other Elements
* Number of studies
Agreement between
researchers
Overall Rating
Study consisted of 9,386 total participants consisting of all ages.
The data were representative of the U.S. population.
The study provides a distribution on showering duration.
The study includes distributions for showering duration. Study is based on
short-term data.
Measurement or recording error may occur because diaries are based on
24-hour recall.
One: the study was a national study.
Recommendation is based on only one study but it is a widely accepted
study and average value is comparable to a second key study.
High
High
High
High
Medium
Low
High
High
June 2000
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4
5
6
7
8
9
10
11
12
13
14
Table 9-56. Confidence in Activity Patterns Recommendations (cont'd)
Considerations
SHOWER FREQUENCY
Study Elements
Level of peer review
Accessibility
Reproducibility
Focus on factor of
interest
Data pertinent to US
Primary data
Currency
Adequacy of data
collection period
Rationale
The study received high level of peer review.
Currently, raw data is available to only EPA. It is not known when data
will be publicly available.
Results can be reproduced or methodology can be followed and
evaluated provided comparable economic and social conditions exists.
The survey collected information on duration and frequency of selected
activities and time spent in selected micro-environments.
The data represents the U.S. population
The study was based on primary data.
The study was published in 1996.
The data were collected between October 1992 and September 1994.
Rating
High
Low
High
High
High
High
High
High
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
Validity of approach
Study size
Representativeness of
the population
Characterization of
variability
Lack of bias in study
design (high rating is
desirable)
Measurement error
Other Elements
* Number of studies
Agreement between
researchers
Overall Rating
The study used a valid methodology and approach which, in addition to
24-hour diaries, collected information on temporal conditions and
demographic data such as geographic location and socioeconomic status
for various U.S. subgroups. Responses were weighted according to this
demographic data.
The study consisted of 9,386 total participants consisting of all age
groups
Studies were based on the U.S. population.
The study provided data that varied across geographic region, race,
gender, employment status, educational level, day of the week, seasonal
conditions, and medical conditions of respondent-
Study is based on short term data-
Measurement or recording error may occur because diaries were based on
24-hour recall.
One; the study was based on one, primary, national study.
Recommendation was based on only one study.
High
High
High
High
Medium
Medium
Low
Not
Ranked
High
June 2000
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Table 9-56. Confidence in Activity Patterns Recommendations (cont'd)
2
*ป
4
5
6
7
8
9
10
11
12
13
14
Considerations
Rationale
Rating
TIME SPENT SWIMMING
Study Elements
* Level of peer review
Accessibility
Reproducibility
Focus on factor of
interest
Data pertinent to US
Primary data
Currency
Adequacy of data
collection period
Study received high level of peer review.
Currently, raw data is available to only EPA. It is not known when data
will be publicly available.
Results can be reproduced or methodology can be followed and
evaluated provided comparable economic and social conditions exists.
The survey collected information on duration and frequency of selected
activities and time spent in selected micro-environments.
The data represents the U.S. population
The study was based on primary data.
The study was published in 1996.
The data were collected between October 1992 and September i994.
High
Low
High
High
High
High
High
High
15
16
17
18
19
20
21
22
23
24
25
26
27
28
KZ9
Validity of approach
Study size
Representativeness of
the population
Characterization of
variability
Lack of bias in study
design (high rating is
desirable)
Measurement error
Other Elements
Number of studies
Agreement between
researchers
Overall Rating
The study used a valid methodology and approach which, in addition to
24-hour diaries, collected information on temporal conditions and
demographic data such as geographic location and socioeconomic status
for various U.S. subgroups. Responses were weighted according to this
demographic data.
The study consisted of 9.336 total participants consisting of all age
groups
Studies were based on the U.S. population.
The study provided data that varied across geographic region, race,
gender, employment status, educational level, day of the week, seasonal
conditions, and medical conditions of respondent..
The study includes distributions for swimming duration. Study is based
on short term data.
Measurement or recording error may occur because diaries were based
on 24-hour recall.
One; the study was based on one, primary, national study.
Recommendation was based on only one study.
High
High
High
High
Medium
Medium
Low
Not
Ranked
High
June 2000
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4
5
6
7
S
9
10
11
12
13
14
15
Table 9-56. Confidence in Activity Patterns Recommendations (cont'd)
Considerations
RESIDENTIAL TIME
Studv Elements
Level of peer review
Accessibility
Reproducibility
* Focus on factor of
interest
ป Data'pertinent to US
Primary data
Currency
Adequacy of data
collection period
Validity of approach
Rationale
SPENT INDOORS AND OUTDOORS
The study received high level of peer review.
Currently, raw data is available to oniy EPA. It is not known when data
will be publicly available.
Results can be reproduced or methodology can be followed and
evaluated provided comparable economic and social conditions exists.
The survey collected information on duration and frequency of selected
activities and time spent in selected micro-environments.
The data represents the U.S. population
The study was based on primary data.
The study was published in 1 996.
Data were collected between October 1992 and September 1994.
The study used a valid methodology and approach which, in addition to
Rating
High
Low
High
High
High
High
High
High
High
16 Studv size
17 Representativeness of
18 the population
19 Characterization of
20 variability
21 Lack of bias in study
22 design (high rating is
23 desirable)
24 Measurement error
25 Other Elements
26 Number of studies
27 Agreement between
28 researchers
29 Overall Rating
24-hour diaries, collected information on temporal conditions and
demographic data such as geographic location and socioeconomic status
for various U.S. subgroups. Responses were weighted according to this
demographic data.
The study consisted of 9,386 total participants consisting of all age
groups
The studies were based on the U.S. population.
The study provided data that varied across geographic region, race,
gender, employment status, educational level, day of the week, seasonal
conditions, and medical conditions of respondent..
The study includes distribitions for time spent indoors and outdoors at
ones residence. Study is based on short term data.
Measurement or recording error may occur because diaries were based
on 24-hour recall.
One; the study was based on one. primary, national study.
Recommendation was based on only one study.
High
High
High
Medium
Medium
Low
Not
Ranked
High
June 2000
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2
*>
4
5
6
7
8
9
10
11 '
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
Table
Considerations
TIME SPENT PLAYING
Study Elements
Level of peer review
Accessibility
Reproducibility .
Focus on factor of
interest
Data pertinent to US
Primary data
Currency
Adequacy of data
collection period
Validity of approach
Study size
Representativeness of
the population
Characterization of
variability
Lack of bias in study
design (high rating is
desirable)
Measurement error
Other Elements
* Number of studies
Agreement between
researchers
Overall Rating
9-56. Confidence in Activity Patterns Recommendations (cont'd)
Rationale
ON SAND OR GRAVEL
The study received high level of peer review.
Currently, raw data are available to only EPA. It is not known when data
will be publicly available.
Results can be reproduced or methodology can be followed and evaluated
provided comparable economic and social conditions exists.
The survey collected information on duration and frequency of selected
activities and time spent in selected micro-environments.
The data represents the U.S. population.
The study was based on primary data.
The study was published in 1 996.
The data were collected between October 1992 and September 1994.
The study used a valid methodology and approach which, in addition to
24-hour diaries, collected information on temporal conditions and
demographic data such as geographic location and socioeconomic status
for various U.S. subgroups. Responses were weighted according to this
demographic data.
The study consisted of 9,386 total participants consisting of all age
groups.
The studies were based on the U.S. population.
The study provided data that varied across geographic region, race,
gender, employment status, educational level, day of the week, seasonal
conditions, and medical conditions of respondent..
The study includes distributions for bathing duration. Study is based on
short-term data.
Measurement or recording error may occur because diaries were based on
24-hour recall.
One; the study was based on one. primary, national study.
Recommendation was based on only one study.
Rating
High
Low '
High
High
High
High
High
High
High
\
High
High
High
Medium
Medium
Low
Not
Ranked
High
June 2000
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2
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4
5
6
7
8
9
10
11
12
13
14
Table
Considerations
TIME SPENT PLAYING
Study Elements
Level of peer review
* Accessibility
Reproducibility
Focus on factor of
interest
Data pertinent to US
Primary data
Currency
Adequacy of data.
collection period
9-56. Confidence in Activity Patterns Recommendations (cont'd)
Rationale
ON GRASS
The study received high level of peer review.
Currently, raw data are available to only EPA. It is not known when data
will be publicly available.
Results can be reproduced or methodology can be followed and evaluated
provided comparable economic and social conditions exists.
The survey collected information on duration and frequency of selected
activities and time spent in selected micro-environments.
The data represents the U.S. population.
The study was based on primary data.
The study was published in 1996.
The data were collected between October 1992 and September 1994.
Rating
High
Low
High
High
High
High
High
High
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
Validity of approach
Study size
Representativeness of
the population
Characterization of
variability
Lack of bias in study
design (high rating is
desirable)
Measurement error
Other Elements
Number of studies
* Agreement between
researchers
Overall Rating
The study used a valid methodology and approach which, in addition to
24-hour diaries, collected information on temporal conditions and
demographic data such as geographic location and socioeconomic status
for various U.S. subgroups. Responses were weighted according to this
demographic data.
The study consisted of 9,386 total participants consisting of ail age
groups.
The studies were based on the U.S. population.
The study provided data that varied across geographic region, race,
gender, employment status, educational level, day of the week, seasonal
conditions, and medical conditions of respondent..
The study includes distributions for bathing duration. Study is based on
short-term data.
Measurement or recording error may occur because diaries were based on
24-hour recall.
One; the study was based on one. primary, national study.
Recommendation was based on only one study.
High
High
High
High
Medium
Medium
Low
Not
Ranked
High
June 2000
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4
5
6
7
8
9
10
Table 9-57. Summary of Activity Pattern Studies
Summary of Activity Patterns Studies
Study
Timmer(1985)
Robinson & Thomas ( 1991 )
Wiley (1991)
Davis (1995)
Tsang&Kleipeis(1996)
Funk (1998)
Age Groups
(yrs)
3-5.6-8,9-11. 12-
14. 15-17
12-adults
0-2.3-5.6-8.9-11
10-60 (months)
1-4.5-11.12-17
6-11. 12-17
Sample Size
922
1.762
(California)
2.762 (national)
1.200
92
Varies with age
groups and
activities
768
Population
National
California and
national
California
Washington State
U.S. national
California
Activities
18 microenvironments
16 microenvtronmenis
10 microenvironments
Activities grouped
into indoors and
outdoors
23 microenvironments
Activities grouped
11
Hubal (20GO)
0.1.2.3.4.5.6.7.
8.9. 10. II
2.640
Based on Wiley
(199 i). Johnson
(1989). and Tsang
&Kleipeis(l996)
into low. medium, and
high ventilation levels
Activities grouped
into indoors at home-
indoors at school.
outdoors at home.
outdoors at part, and
in vehicle
12
June 2000
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5
6
7
S
9
10
11
12
13
14
15
Table
Age (years)
3-5
6-8
9-11
12-14
15-17
12 and older
0-2
3-5
6-8
9-n
1 Mean, of weekday i
9-58. Summary of Mean Time
Time Indoors
(hours/day)1
19
20
20
20
19
21 (national)
21 (California)
20
18.8
19.7
19.9
and weekend rounded up to two
Spent indoors and Outdoors from Several Studies
Time Outdoors Study
(hours/day)1
2.8 Timmer 1985
2.2
1.8
1.8
1.9
1 .2 (national Robinson and Thomas 1991
1.4 (California)
4 Wiley 1991
5.2
4.4
4.1
significant figures.
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1
2
3
4
Table 9-59. Summary of Recommended Values for Activity Factors
Type
Value
Study
8
9
10
11
12
13
Time Indoors
Time Outdoors
Taking Showers
Swimming
Residential
Indoors
Outdoors
Playing on Sand or Gravel
Playing on Grass
Ages 3-5 years (19 hours/day)
Ages 6-14 years (20 hours/day)
Ages 12-17 years (19 hours/day)
Ages 3-5 years (2.8 hours/day)
Ages 6-8 years (2.2 hours/day)
Ages 9-14 years (1.8 hours/day)
Ages 15-17 years (1.9 hours/day)
10 min/day shower duration
1 shower event/day
1 event/month
60 minutes/event
18hr/day
2 hr/day
60 min/day
60 min/day
Timmeretal., 1985
Tsang and Klepeis, 1996
Tsang and Klepeis, 1996
Tsang and Klepeis, 1996
Tsang and Klepeis, 1996
Tsang and Klepeis, 1996
Tsang and Klepeis, 1996
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10. CONSUMER PRODUCTS
10.1 BACKGROUND
Consumer products may contain toxic or potentially toxic chemical constituents to which
children may be exposed as a result of their use. For example, methylene chloride and other
solvents and carriers are common in consumer products and may have health concerns. Potential
pathways of exposure to consumer products or chemicals released from consumer products
during use can occur via ingestion, inhalation, and dermal contact.
This chapter presents information on the amount of product used, frequency of use. and
duration of use for various consumer products typically found in households. There are limited
data available on consumer product use for the general population and especially for children.
Children can be in environments where household consumer products (Table 10-1) such as
cleaners, solvents, and paints are used. As such, children can be passively exposed to chemicals
in these products. The studies presented in the following sections represent readily available
surveys for which data were collected on the frequency and duration of use and amount of use of-
cleaning products, painting products, household solvent products, cosmetic and other personal
care products, household equipment, pesticides, and tobacco. The reader is referred to the
Exposure Factors Handbook (U.S. EPA, 1997) for a more detailed presentation for use of
consumer products for the general population.
10.2 CONSUMER PRODUCTS USE STUDIES
Tsang andKlepeis (1996) - National Hitman Activity Pattern Survey (NHAPS) - The U.S.
EPA collected information for the general population on the duration and frequency of selected
activities and the time spent in selected microenvironments via 24-hour diaries. Over 9000
individuals from all age groups in 48 contiguous states participated in NHAPS. The survey was
conducted between October 1992 and September 1994. Individuals were interviewed to
categorize their 24-hour routines (diaries) and/or answer follow-up exposure questions that were
related to exposure events. Data were collected based on selected socioeconomic (gender, age,
race, education, etc.) and geographic (census region, state, etc.) factors and time/season (day of
-
-------
week, month) (Tsang and Klepeis, 1996). Data were collected for a maximum of 82 possible
microenvironments and 91 different activities (Tsang and Klepeis, 1996).
As part of the survey, data were also collected on duration and frequency of use of
selected consumer products. These data are presented in Tables 10-2 through 10-6 for age
groups 1-4,5-11, and 12-17 years. Distribution data are presented for selected percentiles (where
possible). Other data are presented in ranges of time spent in an activity (e.g., working with or
near a product being used) or ranges for the number of times an activity involving a consumer
product was performed.
The advantages of NHAPS is that the data were collected for a large number of
individuals, representative of the U.S. general population. However, means cannot be calculated
for consumers who spent more than 60 or 120 minutes (depending on the activity) in an activity
using a consumer product. Therefore, a good estimate of the high consumer activities cannot be
captured.
10.3 RECOMMENDATIONS
Due to the large range and variation among consumer products and their exposure
pathways, it is not feasible to specify recommended exposure values as had been done in other
chapters of this handbook. The user is referred to the contents and references in Chapter 16 of
the Exposure Factors Handbook to derive appropriate exposure factors and review its associated
recommendations.
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10.4 REFERENCES FOR CHAPTER 10
Tsang, A.M.; Klepeis, N.E. (1996) Results tables from a detailed analysis of the National Human Activity Pattern
Survey (NHAPS) response. Draft Report prepared for the U.S. Environmental Protection Agency by
Lockheed Martin, Contract No. 68-W6-001, Delivery Order No. 13.
U.S. EPA (1987) Methods for assessing exposure to chemical substances - Volume 7 - Methods for assessing
consumer exposure to chemical substances. Washington, DC: Office of Toxic Substances. EPA Report
No. 560/5-85-007.
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Table 10-1. Consumer Products Found in the Typical U.S. Household"
Consumer Product Category
Consumer Product
Cosmetics Hygiene Products
Household Furnishings
Garment Conditioning Products
Household Maintenance Products
Adhesive bandages
Bath additives (liquid)
Bath additives (powder)
Cologne/perfume/aftershave
Contact lens solutions
Deodorant/antiperspirant (aerosol)
Deodorant/antiperspirant (wax and liquid)
Depilatories
Facial makeup
Fingernail cosmetic's
Hair coloring/tinting products
Hair conditioning products
Hairsprays (aerosol)
Lip products
Mouthw ash/breath freshener
Sanitary napkins and pads
Shampoo
Shaving creams (aerosols)
Skin creams (non-drug)
Skin oils (non-drug)
Soap (toilet bar)
Sunscreen/suntan products
Talc/body powder (non-drug)
Toothpaste
Waterless skin cleaners
Carpeting
Draperies/curtains
Rugs (area)
Shower cunains
Vinyl upholstery, furniture
Ami-static spray (aerosol)
Leather treatment (liquid and wax)
Shoe polish
Spray starch (aerosol)
Suede cleaner/polish (liquid and aerosol)
Textile water-proofing (aerosol)
Adhesive (general) (liquid)
Bleach (household) (liquid)
Bleach (see laundry)
Candles
Cat box litter
Charcoal briquets
Charcoal lighter fluid
Drain cleaner (liquid and powder)
Dishwasher detergent (powder)
Dishwashing liquid
Fabric dye foiY)"
Fabric rinse/softener (liquid)
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Table 10-1. Consumer Products Found in the Typical U.S. Household* (continued)
Consumer Product Category
Consumer Product
Household Maintenance Products
(continued)
Home Building/Improvement Products (DlY)h
Fabric rinse/softener (powder)
Fertilizer (garden) (liquid)
Fertilizer (garden) (powder)
Fire extinguishers (aerosol)
Floor polish/wax (liquid)
Food packaging and packaged food
Furniture polish (liquid)
Furniture polish (aerosol)
General cleaner/disinfectant (liquid)
General cleaner (powder)
General cleaner/disinfectant (aerosol and pump)
General spot/stain remover (liquid)
General spot/stain remover (aerosol and pump)
Herbicide (garden-patio) (Liquid and aerosol)
Insecticide (home and garden) (powder)
Insecticide (home and garden) (aerosol and pump)
insect repellent (liquid and aerosol)
Laundry detergent/bleach (liquid)
Laundry detergent (powder)
Laundry pre-wash/soak (powder)
Laundry pre-wash/soak (liquid)
Laundry pre-wash/soak (aerosol and pump)
Lubricant oil (liquid)
Lubricant (aerosol)
Matches
Metal polish
Oven cleaner (aerosol)
Pesticide (home) (solid)
Pesticide (pet dip) (liquid)
Pesticide (pet) (powder)
Pesticide (pet) (aerosol)
Pesticide (pet) (collar)
Petroleum fuels (home( (liquid and aerosol)
Rug cleaner/shampoo (liquid and aerosol)
Rug deodorizer/freshener (powder)
Room deodorizer (solid)
Room deodorizer (aerosol)
Scouring pad
Toilet bowl cleaner
Toiler bowl deodorant (solid)
Water-treating chemicals (swimming pools)
Adhesives. specialty (liquid)
Ceil ing tile
Caulks/sealers/fillers
Dry wall/wall board
Flooring (vinyl)
House Paint (interior) (liquid)
House Paint and Slain (exterior) (liquid)
Insulation (solid)
Insulation (foam)
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Table 10-1. Consumer Products Found in the Typical U.S. Household3 (continued)
Consumer Product Category
Consumer Product
Home Building/Improvement Products (DIY)"1
(Continued)
Automobile-related Products
Personal Materials
Paint/varnish removers
Paint thinner/brush cleaners
Patching/ceiling plaster'
Roofing
Refinishing products (polyurethane. varnishes, etc.)
Spray paints (home) (aerosol)
Wall paneling
Wall paper
Wall paper glue
Antifreeze
Car polish/wax
Fuel/lubricant additives
Casoline/diesel fuel
Interior upholstery/components, synthetic
Motor oil
Radiator flush/cleaner
Automotive touch-up paint (aerosol)
Windshield washer solvents
Clothes/shoes
Diapers/vinyl pants
Jewelry
Printed material (colorprinL newsprint, photographs)
Sheets/towels
Toys (intended to be placed in mouths)
* A subjective listing based on consumer use profiles.
" DIY = Do It Yourself.
Source: U.S. EPA. 1987.
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Table 10-2. Number of Minutes Spent in Activities Working with or Near Household Cleaning
Agents Such as Scouring Powders or Ammonia (minutes/day)
Percentiles
Category
Age (years)
Age (years)
Age (years)
Age (years)
Age (years)
Population Group
1-4
5-11
12-17
18-64
>64
N
21
26
41
672
127
I
0
1
0
0
0
2
0
1
0
0
0
5
0
2
0
1
0
10
0
2
0
2
1
25
5
3
2
5
3
50
10
5'
5
10
5
75
15
15
10
20
15
90
20
30
40
60
30
95
30
30
60
121
60
98
12!
30
60
121
120
99
12!
30
60
121
121
100
121
30
60
121
121
Note: A value of "121" for number of minutes signifies that more than 120 minutes were spent: n = doer sample size: percentiles are the
percentage of doers below or equal to a given number of minutes.
Source: Tsang and Klepeis. 1996.
Table 10-3 Number of Minutes Spent Using Any Microwave Oven (minutes/day)
Percentiles
Category
Age (years)
Age (years)
Age (years)
Age (years)
Population Croup
5-11
12-17
18-64
>64
N
62
141
1686
375
I
0
0
0
0
2
0
0
0
0
5
0
0
1
1
10
1
1
2
2
25
1
2
3
3
50
2
3
5
5
75
5
5
10
10
90
10
10
15
20
95
15
15
25
30
98
20
30
45
60
99
30
30
60
60
100
30
60
121
70
Note: A Value of "121" for number of minutes signifies that more than 120 minutes were spent: n = doer sample size: perceniiles are the
percentage of doers below or equal to a given number of minutes.
Source: Tsang and Klepeis. 1996.
Table 10-4. Number of Respondents Using a Humidifier at Home
Age (years)
M
5-11
12-17
Total N
111
88
83
Almost
Every
Day
-i >
jj
IS
21
3-5 Times a
Week
16
10
7
Frequency
1 -2 Times a
Week
7
12
5
1-2 Times a
Month
53
46
49
DK
2
2
1
Note: DK= Don't Know: Refused = Respondent Refused to Answer: N = Number of Respondents
Source: Tsang and Klepeis. 1996.
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Table 10-5. Number of Respondents Indicating that Pesticides Were Applied by the Professional at Home
to Eradicate Insects. Rodents, or Other Pests at Specified Frequencies
Age (years)
1-4
5-11
12-17
Total N
.113
150
143
Number of Times Over a 6-month Period
Pesticides Were Applied by Professionals
None
60
84
90
1-2
35
37
40
3-5
11
10
5
6-9
6
18
6
10+
1
1
*
DK
*
*
2
Note: * - Missing Data: DK= Don't know; Refused = Respondent Refused to Answer; N = Number of Respondents
Source: Tsang and Klepeis. 1996.
Table 10-6. Number of Respondents Reporting Pesticides Applied by the Consumer at Home
To Eradicate Insects. Rodents, or Other Pests at Specified Frequencies
Age (years)
1-4
5-!l
12-17
Total N
. 113
150
143
Number of Times Over a 6-month
Period Pesticides Applied by Resident
None
46
50
45
1-2
46
70
64
3-5
15
24
21
6-9
3
1
5
10+
3
4
g
DK
ซ
1
*
Note: * = Missing Data: DK= Don't know: Refused = Respondent Refused to Answer; N = Number of Respondents
Source: Tsang and Klepeis, 1996.
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1 11. BODY WEIGHT STUDIES
2 .
3 11.1 INTRODUCTION
4 The average daily dose is typically normalized to the average body weight of the exposed
5 population. If exposure occurs only during childhood years, the average child body weight
6 during the exposure period should be used to estimate risk (U.S. EPA, 1989).
7 The purpose of this section is to describe key published studies on body weight for
8 children in the general U.S. population, as described in the Exposure Factors Handbook (U.S.
9 EPA, 1997). Recommended'values are based on the results of these studies.
10
II 11.2 BODY WEIGHT STUDIES
12 Hamill et al. (1979) - Physical Growth: National Center for Health Statistics
13 Percentiles- A National Center for Health Statistics (NCHS) Task Force that included academic
14 investigators and representatives from CDC Nutrition Surveillance Program selected, collated,
15 integrated, and defined appropriate data sets to.generate growth curves for the age interval: birth
to 36 months developed (Hamill et al., 1979). The percentile curves were for assessing the
17 physical growth of children in the U.S. They are based on accurate measurements made on large
18 nationally representative samples of children (Hamill et al., 1979). Smoothed percentile curves
19 were derived for body weight by age (Hamill et al., 1979). Curves were developed for boys and
20 for girls. The data used to construct the curves were provided by the Pels Research Institute,
21 Yellow Springs, Ohio. These data were from an ongoing longitudinal study where
22 anthromopetric data from direct measurements are collected regularly from participants (~ 1,000)
23 in various areas of the U.S. The NCHS used advanced statistical and computer technology to
24 generate the growth curves. Table 11-1 presents the percentiles of weight by sex and age.
25 Figures 11-1 and 11-2 present weight by age percentiles for boys and for girls aged birth to 36
26 months, respectively. Limitations of this study are that mean body weight values were not
27 reported and the data are more that 15 years old. However, this study does provide body weight
28 data for infants less than 6 months old.
29 . NCHS (1987) - Anthropometric Reference Data and Prevalence of Overweight, United
.30 States, 1976-80 - Statistics on anthropometric measurements, including body weight, for the U.S.
31 population were collected by NCHS through the second National Health and Nutrition
June 2000 . 11-1 DRAFT-DO NOT QUOTE OR CITE
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1 Examination Survey (NHANES II). NHANES II was conducted on a nationwide probability
2 sample of approximately 28,000 persons, aged 6 months to 74 years, from the civilian,
3 non-institutionalized population of the United States. Of the 28,000 persons, 20,322 were
4 interviewed and examined, resulting in a response rate of 73.1 percent. The survey began in
5 February 1976 and was completed in February 1980. The sample was selected so that certain
6 subgroups thought to be at high risk of malnutrition (persons with low incomes, preschool
7 children, and the elderly) were oversampled. The estimates were weighted to reflect national
8 population estimates. The weighting was accomplished by inflating examination results for each
9 subject by the reciprocal of selection probabilities adjusted to account for those who were not
10 examined, and post stratifying by race, age, and sex (NCHS, 1987).
11 The NHANES II collected standard body measurements of sample subjects, including
12 height and weight, that were made at various times of the day and in different seasons of the year.
13 This technique was used because one's weight may vary between winter and summer and may
14 fluctuate with recency of food and water intake and other daily activities (NCHS, 1987). Mean
15 body weights and standard deviations for children, ages 6 months to 19 years, are presented in
16 Table 11-2 for boys, girls, and boys and girls combined. Percentile data for children, by age, are
17 presented in Table 11-3 for males, and in Table 11-4 for females. From Table 11-2, the mean
18 body weights for girls and boys are approximately the same from ages 6 months to 14 years.
19 Starting at years 15-19, the difference in mean body weight ranges from 6 to 11 kg.
20 Burmaster et al. (1997)- Lognormal Distributions for Body Weight as a Function of Age
21 for Males and Females in the United States, 1976-1980 - Burmaster et al. (1997) performed data
22 analysis to fit normal and lognormal distributions to the body weights of females and males at
23 age 9 months to 70 years (Burmaster et al., 1997). The 1997 Exposure Factors Handbook used a
24 pre-published version of this paper (U.S. EPA, 1997). The numbers reported in Tables 11-5 and
25 11-6 vary slightly from those reported in the Exposure Factors Handbook (U.S. EPA, 1997).
26 Data used in this analysis were from the second survey of the National Center for Health
27 Statistics, NHANES II, which included 27,801 persons 6 months to 74 years of age in the U.S.
28 (Burmaster et al., 1997). The NHANES II data had been statistically adjusted for non-response
29 and probability of selection, and stratified by age, sex, and race to reflect the entire U.S.
30 population prior to reporting (Burmaster et al., 1997). Burmaster et al. (1997) conducted
31 exploratory and quantitative data analyses, and fit normal and lognormai distributions to
June 2000
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1 percentiles of body weights of children, teens, and adults as a function of age. Cumulative
2 distribution functions (CDFs) were plotted for female and male body weights on both linear and
3 logarithmic scales.
4 Two models were used to assess the probability density functions (PDFs) of children's
5 body weight. Linear and quadratic regression lines were fitted to the data. A number of
6 goodness-of-fit measures were conducted on data generated by the two models. Burmaster et al.
7 (1997) found that lognormal distributions give strong fits to the data for each sex across all age
8 groups. Statistics for the lognormal probability plots for children, ages 9 months to 20 years, are
9 presented in Tables 11-5 and 11-6. These data can be used for further analyses of body weight
10 distribution (i.e., application of Monte Carlo analysis).
11 U.S. EPA, 2000 - Body Weight Estimates Based on NHANES III Data - The EPA Office
12 of Water has estimated body weights for children, in kilograms, by age and gender using data
13 collected during National Health and Nutrition Examination Survey III (NHANES HI), 1988-
14 1994. NHANES III collected body weight data for approximately 15,000 children between the
15 ages of 2 months and 17 years. Table 11-7 Presents the body weight estimates in kilograms by
6 age and gender. Table 11 -8 shows the body weight estimates for the infants under the age of 3
17 months and/or younger, while Figures 11-3 and 11-4 compare the body weights (mean and
18 median) between male and female among various age groups, respectively.
19 The limitations of these data are (1) the data were not available for infants under 2
20 months old, and (2) the data are roughly 6-12 years old. With the upward trends in body weight
21 from NHANES II (1976-1980) to NHANES III which may still be valid, the data in Tables 11-7
22 and 11-8 may underestimate current body weights. Adjustment factors may be needed to update
23 the estimates from 1988-1994 data to 2000. However, the data are national in scope and
24 represent the general children's population.
25
26 11.3 RECOMMENDATIONS
27 The recommended values for body weight are summarized in Table 11-9. Table 11-10
28 presents the confidence ratings for body weight recommendations.
29 For infants (birth to 6 months), appropriate values for body weight may be selected from
Table 11-1. These data (percentile only) are presented for male and female infants.
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1
2
3
4
For children, appropriate mean values for .weights may be selected from Table 11-2.
If percentile values are needed, these data are presented in Table 11-3 for male children and in
Table 11-4 for female children.
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11.4 REFERENCES FOR CHAPTER 11
3 Burmaster, D.E.; Lloyd, K.J.; Crouch, E.A.C. (1997) Lognormal distributions for body weight as a function of age
4 for males and females in the United States, 1976-1980. Risk Anal. 17(4):499-505.
5
6 Hamill, P.V.V.; Drizd, T.A.; Johnson, C.L.; Reed, R.B.; Roche, A.F.; Moore, W.M. (1979) Physical growth:
7 National Center for Health Statistics Percentiles. American J. Clin. Nutr. 32:607-609.
8
9 National Center for Health Statistics (NCHS) (1987) Anthropometric reference data and prevalence of overweight,
10 United States, 1976-80. Data from the National Health and Nutrition Examination Survey, Series 11,
11 No. 238. Hyattsville, MD: U.S. Department of Health and Human Services, Public Health Service, National
12 Center for Health Statistics. DHHS Publication No. (PHS) 87-1688.
13
14 U.S. EPA (1989) Risk assessment guidance for Superfund, Volume 1: Human health evaluation manual.
15 Washington, DC: U.S. Environmental Protection Agency, Office of Emergency and Remedial Response.
16 EPAV540/1-89/002.
17
18 U.S. EPA (1997) Exposure Factors Handbook. Washington, DC: Office of Research and Development. EPA/600-
19 P-95/002F.
20
21 U.S. EPA (2000) Memorandum entitied: Bodyweight estimates on NHANES HI data, revised, Contract 68-C-
22 99-242, Work Assignment 0-1 from Bob Clickner, Westat Inc. to Helen Jacobs, U.S. EPA dated
23 March 3,2000.
24
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1
2
3
Table 11-1. Smoothed Percentiles of Weight (In Kg) by Sex And Age:
Statistics From NCHS And Data From Fels Research Institute, Birth to 36 Months
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
Smoothed1 Percentile
Sex and Age
Male
Birth
I Month
3 Months
6 Months
9 Months
12 Months
18 Months
24 Months
30 Months
36 Months
Female
Birth
1 Month
3 Months
6 Months
9 Months
12 Months
18 Months
24 Months
30 Months
36 Months
5th
10th
25th
50th
75th
90th
95th
Weight in Kilograms
2.54
3.16
4.43
6.20
7.52
8.43
9.59
10.54
11.44
12.26
2.36
2.97
4.18
5.79
7.00
7.84
8.92
9.87
10.78
11.60
2.78
3.43
4.78
6.61
7.95
8.84
9.92
10.85
11.80
12.69
2.58
3.22
4.47
6.12
7.34
8.19
9.30
10.26
11.21
12.07
3.00
3.82
5.32
7.20
8.56
9.49
10.67
11.65
12.63
13.58
2.93
3.59
4.88
6.60
7.89
8.81
10.04
11.10
12.11
12.99
3.27
4.29
5.98
7.85
9.18
10.15
11.47
12.59
13.67
14.69
3-23
3.98
5.40
7.21
8.56
9.53
10.82
11.90
12.93
13.93
3.64
4.75
6.56
8.49
. 9.88
10.91
12.31
13.44
14.51
15.59
3.52
4.36
5.90
7.83
9.24
10.23
11.55
12.74
13.93
15.03
3.82
5.14
7.14
9.10
10.49
11.54
13.05
14.29
15.47
16.66
3-64
4.65
6.39
8.38
9.83
10.87
12.30
13-57
14.81
15.97
4.15
5.38
7.37
9.46
10.93
11.99
13.44
14.70
15-97
17.28
3.81
4.92
6.74
8.73
10.17
11.24
12,76
14.08
15.35
16.54
aSmoothed by cubic-spline approximation.
\
Source: Hamill et al. (1979).
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18
17
16
15
14
13
12
ง 11
c
Z 10
o>
9
8
7
6
5
4
3
.95th
90th
75th
50th
25th-
10th-
5th
39.7
37.5
35.3
33.1
30.9
28.7
26.5
24.3
22.0
19.8
17.6
15.4
13.2
11.0
8.8
6.6
4.4
2.2
I
&
3
o
o
c
3
a
09
0 3 6 9 12 15 18 21 24 27 30 33 36
Age in Months
Figure 11-1. Weight by Age percentiles for Girls Aged Birth-36 Months
Source: Hamill et al. (1979).
June 2000 11 -7 DRAFT-DO NOT QUOTE OR CITE
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0
6 9 12 15 18 21 24 27 30 33 36
Age in Months
Figure 11-2: Weight by Age Percentiles for Boys Aged Birth-36 Months
Source: Hamill et ai. (1979).
i
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June 2000
11-8
DRAFT-DO NOT QUOTE OR CITE
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1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
6
27
28
29
30
31
32
33
Table 11-2. Body Weights of Children" (Kilograms)
Age
6-1 1 months
1 year
2 years
3 years
4 years
5 years
6 years
7 years
8 years
9 years
10 years
1 1 years
12 years
13 years
14 years
15 years
1 6 years
1 7 years
18 years
! 9 years
Boys
Mean (kg)
9.4
11.8
13.6
. 15.7
17.8
!9.8
23.0
25.1
28.2
31.1
36.4
40.3
44.2
49.9
57.!
61.0
67.1
66.7
7U
71.7
Std. Dev.
1.3
1.9
1.7
2.0
2.5
3.0
4.0
3.9
6.2
6.3
7.7
10.1
10.1
12.3
11.0
11.0
12.4
11.5
12.7
11.6
Girls
Mean (kg)
8.8
10.8
13.0
14.9
17.0
19.6
22.1
24.7
27.9
31.9
36.1
41.8
46.4
50.9
54.8
55.1
58.1
59.6
59.0
60.2
Std. Dev.
!.2
1.4
1.5
2.1
2.4
3.3
4.0
5.0
5.7
8.4
8.0
10.9
1 0.1
11.8
11.1
9.8
10.1
11.4
11.1
11.0
Boys and Girls
Mean
(kg)
9.1
11.3
13.3.
15.3
17.4
19.7
22.6
24.9
28.1
31.5
36.3
41.1
45.3
50.4
56.0
58.1
62.6
63.2
65.1
66.0
Note: 1 kg = 2.2046 pounds.
alncludes clothing weight, estimated as ranging from 0.09 to 0.28 kilogram.
Source: Adapted from National Center for Health Statistics (NCHS) (1987).
June 2000
11-9
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Table 11-5. Best-fit Parameters for Lognormal Distributions
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Lognormal Probability Plots
Linear Curve
Age Midpoint (yr)
0.75
1.5
2.5
3.5
4.5
5.5
6.5
7.5
8.5
9.5
10.5
11.5
12.5
13.5
14.5
15.5
16.5
17.5
18.5
19.5
^
2.16
2.38
2.56
2.69
2.83
2.98
3.10
3.19
3.31
3.46
3.57
3.71
3.82
3.92
3.99
4.00
4.05
4.08
4.07
4.10
' o,'
0.145
0.129
0.112
0.136
0.134
0.164
0.174
0.174
0.156
0.214
0.199
. 0.226
0.213
0.215
0.187
0.156
0.167
0.165
0.147
0.149
*W2> O", correspond to the mean and standard deviation, respectively, of the lognormal distribution of
body weight (kg).
Source: Burmaster et al. (1997).
June 2000
11-12
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1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
F
24
25
26
27
28
29
30
31
32
Table 11-6. Statistics for Probability Plot Regression Analyses
Male's Body Weights 6 Months to 20 Years of Age
Age Midpoint (yrs)
Lognormal Probability Plots
Linear Curve
ปS o2-
0.75
1.5
2.5
3.5
4.5
5.5
6.5
7.5
8.5
9.5
10.5
11.5
12.5
13.5
14.5
15.5
16.5
17.5
18.5
19.5
2.23
2.46
2.60
2.75
2.87
2.98
3.13
3.21
3.33
3.43
3.59
3.69
3.78
3.88
4.02
4.09
4.20
4.19
4.25
4.26
0.132
0.119
0.120
0.114
0.133
0.138
0.145
0.151
0.181
0.165 -
0.195
0.252
0.224
0.215
0.181
0.159
0.168
0.167
0.159
0.154
*U2, O2 - correspond to the mean and standard deviation, respectively, of the lognormal distribution of
body weight (kg).
Source: Burmaster et al. (1997).
June 2000
11-13
DRAFT-DO NOT QUOTE OR CITE
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2
Table 1 1-8. Body Weight Estimates (in kilograms) by Age, U.S. Population 1988-94
6
7
10
11
12
13
14
15
16
Age
Newborn
1 Month
2 Months
3 Months
3 Months and
Younger
Sample Size
NA
NA
243
190
433
Population
NA
NA
408.837
332.823
741.660
Median
NA
NA
6.3
7.0
6.6
Male and Female
Mean
NA
NA
6.3
6.9
6.6
95% CI
NA
NA
6.1-6.4
6.7-7.1
6.4-6.7
N A = Not available.
CI = Confidence Intervals.
Source: U.S. EPA (2000).
June 2000
11-15
DRA
-------
1
2
3
4
5
6
7
8
Table 11-9. Summary of Recommended Values for Body Weight
Population
Mean
Upper Percent! le
Multiple Percent!les
Children
Infants
See Table 11-2
Not Available
See Tables 11-3 and 11-4 See Tables 11-3 and 11-4
See Table 11-1 See Table 11-1
June 2000
11-16
-------
1
.2
Table 11-10. Confidence in Body Weight Recommendations
Considerations
Rationale
Ratine
Study Elements
* Level of peer review
Accessibility
Reproducibility
Focus on factor of interest
Data pertinent to US
Primary data
Currency
Adequacy of data collection
period
Validity of approach
Study size
Representativeness of the
population
Characterization of variability
Lack of bias in study design
(high rating Is desirable)
Measurement error
NHANES II was the major source of data for NCHS (1987). This is a High
published study which received a high level of peer review. The Hamill et
al. (1979) is a peer reviewed journal publication.
Both studies are available to the public. High
Results can be reproduced by analyzing NHANES H data and the Pels High
Research Institute data..
The studies focused on body weight, the exposure factor of interest. High .
The data represent the U.S. population. High
The primary data were generated from NHANES II data and Pels studies. Medium
thus these data are secondary.
The data were collected between 1976-1980. Low
The NHANES II study included data collected over a period of 4 years. High
Body weight measurements were taken at various times of the day and at
different seasons of the year.
Direct body weights were measured for both studies. For NHANES II. High
subgroups at risk for malnutrition were over-sampled. Weighting was
accomplished by inflating examination results for those not examined and
were stratified by race. age. and sex. The Pels data are from an ongoing
longitudinal study where the data are collected regularly.
The sample size consisted of 28.000 persons for NHANES II. Author High
noted in Hamill et al. (1979) that the data set was large.
Data collected focused on the U.S. population for both studies. High
Both studies characterized variability regarding age and sex. Additionally High
NHANES II characterized race (for Blacks. Whites and total populations)
and sampled persons with low income.
There are no apparent biases in the study designs for NHANES 11. The Medium-
study design for collecting the pels data was not provided. High
For NHANES II. measurement error should be low since body weights High
were performed in a mobile examination center using standardized
procedures and equipment. Also, measurements were taken at various
times of the day to account for weight fluctuations as a result of recent
food or water intake. The authors of Hami 11 et al. (1979) report that study
data are based on accurate direct measurements from an ongoing
longitudinal studv.
Other Elements
Number of studies
* Agreement between
researchers
Overall Rating
There are two studies.
There is consistency among the two studies.
Low
High
High
June 2000
11-17
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1 12. LIFETIME
2
3 12.1 INTRODUCTION
4 The length of an individual's life is an important factor to consider when evaluating
5 cancer risk because the dose estimate is averaged over an individual's lifetime. Since the
6 averaging time is found in the denominator of the dose equation, a shorter lifetime would result
7 in a higher potential risk estimate," and conversely, a longer life expectancy would produce a
8 lower potential risk estimate. Children have more years of future life than adults. Therefore,
9 they have more time to develop any chronic diseases that might be triggered by early
10 environmental exposures. Diseases initiated by chemical hazards require several decades to
11 develop, and early childhood exposure to certain carcinogens or toxicants is more likely to lead
12 to disease than the same exposures later in life (NRDC, 1997).
13
14 12.2 DATA ON LIFETIME
15 Statistical data on life expectancy are published annually by the U.S. Department of
Commerce in the publication: "Statistical Abstract of the United States." The latest year for
17 which statistics are available is 1993. Available data on life expectancies for various
18 subpopulations bom in the years 1980 to 1993 are presented in Table 12-1. Data for 1993 show
19 that the life expectancy for an average person born in the United States in 1993 is 75.5 years
20 (U.S. Bureau of the Census, 1999). The table shows that the overall life expectancy has averaged
21 approximately 75 years since 1982. The average life expectancy for males in 1993 was
22 . 72.2 years, and 78.8 years for females. The data consistently show an approximate 7 years
23 difference in life expectancy for males and females from 1980 to present. Table 12-1 also
24 indicates that the 1993 life expectancy for white males (73.1 years) is consistently longer than for
25 Black males (64.6 years). Additionally, it indicates that the 1993 life expectancy for White
26 females (79.5 years) is longer than for Black females (73.7), a difference of almost 6 years.
27 Table 12-1 also shows that the projected life expectancy for children born in the year 2000 (76.4
28 years) is longer than for those born in the 1980s (73.7 years). Table 12-2 presents data for
29 expectation of life for persons who were at a specific age in year 1996. These data are available
0 by age, gender, and race and may be useful for deriving exposure estimates based on the age of a
March 2000 12-1 DRAFT-DO NOT QUOTE OR CITE
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1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
specific subpopulation. The data show that expectation of life is longer for females and for
Whites.
12.3 RECOMMENDATIONS
Current data suggest that 75 years would be an appropriate value to reflect the -average
life expectancy of children in the current general population and is the recommended value. If
gender is a factor considered in the assessment, note that the average life expectancy value for
females is higher than for males. It is recommended that the assessor use the 1993 value of 72.2
years for males or 78.8 years for females. If race is a consideration in assessing exposure for
male individuals, note that the life expectancy is about 8 years longer for Whites than for Blacks.
It is recommended that the assessor use the 1993 values of 73.1 years and 64.6 years for White
males and Black males, respectively. Table 12-3 presents the confidence rating for life
expectancy recommendations.
This recommended value is different than the 70 years commonly assumed for the general
population in EPA risk assessments. Assessors are encouraged to use values which most
accurately reflect the exposed population. When using values other than 70 years, however, the
assessors should consider if the dose estimate will be used to estimate risk by combining with a
dose-response relationship which was derived assuming a lifetime of 70 years. If such an
inconsistency exists, the assessor should adjust the dose-response relationship by multiplying by
(lifetime/70). The Integrated Risk Information System (IRIS) does not use a 70 year lifetime
assumption in the derivation of RfCs and RfDs, but does make this assumption in the derivation
of some cancer slope factors or unit risks.
March 2000
12-2
DRAFT-DO NOT QUOTE OR CITE
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1
I?
4
5
6
7
12.4 REFERENCES FOR CHAPTER 12
Natural Resources Defense Council. (1997) Our children at risk: the 5 worst environmental threats to their health.
U.S. Bureau of the Census. (1999) Statistical abstracts of the United States.
March 2000
12-3
DRAFT-DO NOT QUOTE OR CITE
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1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
Table 12-1. Expectation of Life at Birth, 1980 to 1993,
And Projections, 1995 to 2010 (Years)3
YEAR Total
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
73.7
74.1
74.5
74.6
74.7
74.7
74.7
74.9
74.9
75.1
75.4
75.5
75.8
75.5
TOTAL
Male Female Total
70.0 77.4 74.4
70.4 77.8 74.8
70.8 78.1 75.1
71.0 - 78.1 75.2
71.1 78.2 75.3
71.1 78.2 75.3
71.2 78.2 75.4
71.4 78.3 75.6
71.4 78.3 75.6
71.7 78.5 75.9
71.8 78.8 76.1
71.0 78.9 76.3
72.3 79.1 76.5
72.2 78.8 76.3
WHITE
Male
70.7
71.1
71.5
71.6
71.8
71.8
71.9
72.1
72.2
72.5
72.7
72.9
73.2
73.1
BLACK AND OTHERb
Female
78.1
78.4
78.7
78.7
78.7
78.7
78.8
78.9
78.9
79.2
79.4
79.6
79.8
79.5
Total
69.5
70.3
70.9
70.9
71.1
71.0
70.9
71.0
70.8
70.9
71.2
71.5
71.8
71.5
Male
65.3
66.2
66.8
67.0
67.2
67.0
66.8
66.9
66.7
66.7
67.0
67.3
67.7
67.3
Female
73.6
74.4
74.9
74.7
74.9
74.8
74.9
75.0
74.8
74.9
75.2
75.5
75.7
75.5
Total
68.1
68.9
69.4
69.4
69.5
69.3
69.1
69.1
68.9
68.8
69.1
69.3
69.6
69.2
BLACK.
Male
63.8
64.5
65.1
65.2
65.3
65.0
64.8
64.7
64.4
64.3
64.5
64.6
65.0
64.6
Female
72.5
73.2
73.6
73.5
73.6
73.4
73.4
73.4
73.2
73.3
73.6
73.8
73.9
73.7
Projections'
1995
2000
2005
2010
75.8
76.4
76.9
77.4
aExcludes deaths
"Racial
'Based
72.5 78.9 76.5
73.0 79.7 77.4
73.8 80.2 77.9
74.1 80.6 78.6
of nonresidents of the United
73.4
74.2
74.7
75.5
States.
79.6
80.5
81.0
81.6
71.9
NA
NA
NA
67.9
NA
NA
NA
75.7
NA
NA
NA
69.6
69.7
69.9
70.4
65.2
64.6
64.5
65.1
73.9
74.7
75.0
75.5
descriptions were not provided in the data source.
on middle
Series P-25, No. 1
mortality assumptions: for details, see
1130.
U.S. Bureau of the Census, Current
Population Reports,
Source: Bureau of the Census (1999).
March 2000
12-4
DRAFT-DO NOT QUOTE OR CITE
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1
1:
3
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Tabie 12-2. Expectation of Life by Race, Sex, And Age: 1996
Expectation of Life in Years
White
Black
Age in 1990
(years)
At birth
1
7
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
Total
76.1
75.7
74.7
73.7
72.8
.71.8
70.8
. 69.8
68.8
67.8
. 66.9
65.9
64.9
63.9
t
62.9
. 61.9
61.0
60.0
59.1
58.1
Male
73.9
73.4
72.4
71.4
70.5
69.5 . .
68.5
67.5
- 66.5
65.5 .
64.5
63.5
62.6
61.6
60.6
59.6
58.8
57.7
56.8
55.8
Female
79.7
79.1
78.1
77.1
76.2
75.2
75.2
73.2
72.2
71.2
70.2
69.2
68.3
67.3
66.3
65.3
64.3
63.3
62.4
61.4 ,
Male
66.1
66.2
65.2
64.3
63.3
62.4
61.4
60.4
59.4
58.4
57.5
56:5
55.5
54.5
53.5
52.6
51.6
50.7
49.8
48.9
Female
742
74.2
73.2
72.3
71.3
70.3
69.4
68.4
67.4
66.4
65.4
64.4
63.4
62.5
61.5
60.5
59.5
58.6
57.6
56.6
Source: U.S. Bureau of Census (1999).
March 2000
12-5
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Table 12-3. Confidence in Lifetime Expectancy Recommendations
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
Considerations
Study Elements
* Level of peer review
Accessibility
Reproducibility
Focus on factor of interest
Data pertinent to US
Primary data
Currency
Adequacy of data collection period
Validity of approach
* Study size
Representativeness of the population
Characterization of variability
Lack of bias in study design (High
rating is desirabie)
Measurement error
Other Elements
Number of studies
Agreement between researchers
Overall Rating
Rationale
Data are published and have received extensive peer
review.
The study was widely available to the public (Census
data).
Results can be reproduced by analyzing Census data.
Statistical data on life expectancy were published in this
study.
The study focused on the U.S. population.
Primary data were analyzed.
The study was published in 1995 and discusses life
expectancy trends from 1 970 to 1993. The study has also
made projections for 1995 until the year 2010.
The data analyzed were collected over a period of years.
Census data is collected and analyzed over a period of
years.
This study was based on U.S. Census data, thus the
population study size is expected to be greater than 1 00.
The data are representative of the U.S. population. -
Data were averaged by gender and race but only for Blacks
and Whites; no other nationalities were represented within
the section.
There are no apparent biases.
Measurement error may be attributed to portions of the
population that avoid or provide misleading information
on census surveys.
Data presented in the section are from the U.S. Bureau of
the Census publication.
Recommendation was based on only one study, but it is
widely accepted.
Rating
High
High '
. High
: High "
High" '
High
High|-
High ^:r
High >v~
Hidh ">'"- '
nign
High -
Medium"
High
Medium
Low >'.
High. -ft
High
March 2000
12-6
DRAFT-DO NOT QUOTE OR CITE
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