TABLE OF CONTENTS

9. ACTIVITY FACTORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1

9.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1

9.2 ACTIVITY PATTERNS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1

9.2.1 Timmer et al., 1985 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-2

9.2.2 Robinson and Thomas, 1991 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3

9.2.3 Wiley et al., 1991 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-4

9.2.4 U.S. EPA, 1992 and U.S. EPA, 2004 . . . . . . . . . . . . . . . . . . . . . . . . . . 9-5

9.2.5 Tsang and Klepeis, 1996 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-5

9.2.6 Funk et al., 1998 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-9

9.2.7 Hubal et al., 2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-10

9.2.8 Wong et al., 2000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-11

9.3 RECOMMENDATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-13
LIST OF TABLES

Table 9-1. Mean Time Spent (minutes) Performing Major Activities Grouped by Age, Sex and

Type of Day . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-16

Table 9-2. Mean Time Spent (minutes) in Major Activities Grouped by Type of Day for Five

Different Age Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-17

Table 9-3. Mean Time Spent Indoors and Outdoors Grouped by Age and Day of the Week

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-18

Table 9-4. Mean Time Spent at Three Locations for both CARB and National Studies (ages 12

years and older) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-19

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 CARB Data . . . . . . . 9-20

Table 9-6. Mean Time Spent (minutes/day) in Various Microenvironments by Type of Day for

the California and National Surveys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-21

Table 9-7. Mean Time Spent (minutes/day) in Various Microenvironments by Age Groups for

the National and California Surveys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-22

Table 9-8. Mean Time (minutes/day) Children Ages 12 Years and Under Spent in Ten Major

Activity Categories for All Respondents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-23

Table 9-9. Mean Time Children Spent in Ten Major Activity Categories by Age a . . . . . . . 9-24

Table 9-10. Mean Time Children Ages 12 Years and Under Spent in Ten Major Activity

Categories Grouped by Seasons and Regions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-25

Table 9-11. Mean Time Children Ages 12 Years and Under Spent in Six Major Location

Categories for All Respondents (minutes/day) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-26

Table 9-12. Mean Time Children Spent in Six Location Categories Grouped by Age and Gender

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-27

Table 9-14. Mean Time Children Spent in Proximity to Two Potential Exposures Grouped by

All Respondents, Age, and Gender . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-29

Table 9-15. Mean Time Spent Indoors and Outdoors Grouped by Age . . . . . . . . . . . . . . . . 9-30

Table 9-16. Water and Soil Contact Exposure Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-31

Table 9-17. Number of Showers Taken Per Day . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-31

Table 9-18. Time (minutes) Spent Taking a Shower and Spent in the Shower Room After

Taking a Shower by the Number of Respondents . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-32

Table 9-19. Time Spent Taking a Shower and Spent in the Shower Room Immediately After

Showering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-32

Table 9-20. Time spent bathing, showering, and in bathroom after bathing and showering

(distribution) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-33

Table 9-21.Time spent bathing, showering, and in bathroom after bathing and showering

(percentiles) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-34

Table 9-22. Range of Number of Times Washing the Hands at Specified Daily Frequencies by

the Number of Respondents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-35

Table 9-23. Number of Minutes Spent Working or Being Near Excessive Dust in the Air

(minutes/day) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-35

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 . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-36

Table 9-25. Number of Minutes Spent Playing on Dirt, Grass . . . . . . . . . . . . . . . . . . . . . . . 9-37

Table 9-26. Number of Minutes Spent Playing on Dirt, Sand/Gravel, or Grass (minutes/day)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-38

Table 9-27. Number of Times Swimming in a Month in Freshwater Swimming Pool by the

Number of Respondents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-39

Table 9-28. Number of Minutes Spent Swimming in a Month in Freshwater Swimming Pool

(minutes/month) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-39

Table 9-29. Time Spent Sleeping/Napping: Whole Population and Doers Only: Percentile Values

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-40

Table 9-30. Time Spent Attending School Full-Time: Whole Population and Doers Only:

Percentile Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-40

Table 9-31. Time Spent in Active Sports: Whole Population and Doers Only: Percentile Values

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-41

Table 9-32. Time Spent on Exercise: Whole Population and Doers Only: Percentile Values

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-41

Table 9-33. Time Spent on Outdoor Recreation: Whole Population and Doers Only: Percentile

Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-42

Table 9-34. Time Spent on Walking: Whole Population and Doers Only: Percentile Values

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-42

Table 9-35. Time Spent Bathing: Whole Population and Doers Only: Percentile Values . . . 9-43

Table 9-36. Time Spent Eating: Whole Population and Doers Only: Percentile Values . . . . 9-43

Table 9-37. Time Spent at Restaurants: Whole Population and Doers Only: Percentile Values

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-44

Table 9-38. Time Spent Indoors at School: Whole Population and Doers Only: Percentile Values

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-44

Table 9-39. Time Spent on School Grounds/Playgrounds: Whole Population and Doers Only:

Percentile Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-45

Table 9-40. Time Spent at Home in Kitchen: Whole Population and Doers Only: Percentile

Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-46

Table 9-41. Time Spent at Home in Living Room/Family Room/Den: Whole Population and

Doers Only: Percentile Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-46

Table 9-42. Time Spent at Home in Dining Room: Whole Population and Doers Only: Percentile

Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-47

Table 9-43. Time Spent at Home in Bathroom: Whole Population and Doers Only: Percentile

Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-47

Table 9-44. Time Spent at Home in Bedroom: Whole Population and Doers Only: Percentile

Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-48

Table 9-45. Time Spent at Home in Study/Office: Whole Population and Doers Only: Percentile

Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-48

Table 9-46. Time Spent at Home in Garage: Whole Population and Doers Only: Percentile

Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-49

Table 9-47. Time Spent at Home: All Rooms Combined: Whole Population and Doers Only:

Percentile Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-49

Table 9-48. Time Spent in an Car: Whole Population and Doers Only: Percentile Values . . 9-50

Table 9-49. Time Spent in a Truck (Pickup or Van): Whole Population and Doers Only:

Percentile Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-50

Table 9-50. Time Spent in a Truck (Not Pickup or Van): Whole Population and Doers Only:

Percentile Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-51
Table 9-51. Time Spent on a Bus: Whole Population and Doers Only: Percentile Values . . . 9-51

Table 9-52. Time Spent on a Train: Whole Population and Doers Only: Percentile Values . 9-52

Table 9-53. Time Spent on an Airplane: Whole Population and Doers Only: Percentile Values

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-52

Table 9-54. Time Spent on a Boat: Whole Population and Doers Only: Percentile Values . . 9-53

Table 9-55. Total Time Spent Inside Vehicles: Whole Population and Doers Only: Percentile

Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-53

Table 9-56. Time Spent Inside Grocery/Convenience Stores, Other Stores, and Malls: Whole

Population and Doers Only: Percentile Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-54

Table 9-57. Average Time Spent Inside and Outside, By Age Category . . . . . . . . . . . . . . . . 9-54

Table 9-58. Statistics for 24-hour Cumulative Number of Minutes Spent with Smokers Present

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-55

Table 9-59. Gender and Age Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-56

Table 9-60. Assignment of At-Home Activities to Ventilation Levels for Children . . . . . . . 9-57

Table 9-61. Aggregate Time Spent (minutes/day) At-Home in Activity Groups by Adolescents

and Childrena . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-58

Table 9-62. Comparison of Mean Time (minutes/day) Spent At-Home by Gendera

 (Adolescents)

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-58

Table 9-63. Comparison of Mean Time (minutes/day) Spent At-Home by Gender and Age for

Childrena . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-58

Table 9-64. Number of Person-Days/Individualsa for Children in CHADa Database . . . . . . 9-59

Table 9-65. Number of Hours Per Day Children Spend in Various Microenvironments by Age

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-60

Table 9-66. Average Number of Hours Per Day Children Spend Doing Various Macroactivities

While Indoors at Home . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-61

Table 9-67. Number of Hours Per Day Children Spend in Various Microenvironments by Age -

Recast Into New Standard Age Categories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-62

Table 9-68. Number of Hours Per Day Children Spend in Various Macroactivities While

Indoors at Home - Recast Into New Standard Age Categories . . . . . . . . . . . . . . . . . . 9-63

Table 9-69. Number and percentage of respondents with children and those reporting outdoor

playa

 activities in both warm and cold weather . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-64

Table 9-70. Play frequency and duration for all child players (from SCS-II data) . . . . . . . . 9-64

Table 9-71. Hand washing and bathing frequency for all child players (from SCS-II data) . 9-65

Table 9-72 NHAPS and SCS-II play durationa

 comparison . . . . . . . . . . . . . . . . . . . . . . . . . . 9-65

Table 9-73. NHAPS and SCS-II hand wash frequency comparison . . . . . . . . . . . . . . . . . . . 9-66

Table 9-77. Confidence in Activity Patterns Recommendations . . . . . . . . . . . . . . . . . . . . . . 9-70
9-1

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 to a

8 child until an activity is performed that subjects the child to contact with those contaminants. An

9 activity or time spent will vary on the basis of, for example, culture, hobbies, location, gender,

10 age, and personal preferences. It is difficult to accurately collect/record data for a child’s

11 activity patterns (Hubal et al., 2000). Children engage in more contact activities than adults;

12 therefore, a much wider distribution of activities need to be considered when assessing children’s

13 exposure (Hubal et al., 2000). Behavioral patterns, preferred activities, and developmental

14 stages result in different exposures for children than for adults (Chance and Harmsen, 1998).

15 This section summarizes data on how much time children spend participating in various

16 activities in various microenvironments and on the frequency of performing various activities. 

17 These data cover a wide scope of activities and populations, which are arranged by age group

18 when such data are available.

19 One of the objectives of this Handbook is to provide recommended exposure factor

20 values using a consistent set of age groups. In this chapter, several studies are used as sources for

21 activity pattern data. In some cases, the source data could be retrieved and analyzed using the

22 standard age groupings introduced in Chapter 1 of this Handbook. In other cases, the original

23 source data were not available, and the study results are presented here using the same age

24 groups as the original study, whether or not they conform to the standard age groupings.

25

26 9.2 ACTIVITY PATTERNS

27 This section briefly describes published time-use studies that provide information on

28 time-activity patterns of children in the U.S. For a detailed description of the studies, the reader

29 is referred to the Exposure Factors Handbook (U.S. EPA, 1997).

30

31
9-2

1 9.2.1 Timmer et al., 1985

2 Timmer et al. (1985) conducted a study using the data obtained on children's time use

3 from a 1981-1982 panel study. A total of 922 children between the ages of 3 and 17 years

4 participated in the survey, which used a time diary and a standardized interview. The time diary

5 involved children reporting their activities beginning at 12.00 AM the previous night, the

6 duration and location of each activity, the presence of another individual, and whether they were

7 performing other activities at the same time. The standardized interview was administered to the

8 children to gather information about their psychological, intellectual (using reading

9 comprehension tests), and emotional well-being; their hopes and goals; their family

10 environment; and their attitudes and beliefs.

11 The mean time spent performing major activities on weekdays and weekends by age, sex,

12 and type of day is presented in Table 9-1. On weekdays, children spend about 40% of their time

13 sleeping, 20% in school, and 10% eating, washing, dressing, and performing other personal

14 activities (Timmer et al., 1985). The data in Table 9-1 indicate that girls spent more time than

15 boys performing household work and personal care activities and less time playing sports. Also,

16 the children spent most of their free time watching television. 

17 Table 9-2 presents the mean time children spent during weekdays and weekends

18 performing major activities by five different age groups. The significant effects of each variable

19 (i.e., age and sex) are also shown. Older children spent more time performing household and

20 market work, studying, and watching television and less time eating, sleeping, and playing. The

21 authors estimate that, on average, boys spent 19.4 hours a week and girls spent 17.8 hours per

22 week watching television.

23 A limitation associated with this study is that it was conducted in 1981. It is likely that

24 activity patterns in children have changed from 1981 to the present. Thus, application of these

25 data for current exposure assessment may bias exposure assessment results. Another limitation

26 is that the data do not provide overall annual estimates of children’s time use since data were

27 collected only during the time of the year when children attend school and not during school

28 vacation.

29 EPA estimated the total time indoors and outdoors using the Timmer data. Activities

30 performed indoors were assumed to include household work, personal care, eating, sleeping,

31 attending school, studying, attending church, watching television, and engaging in household
9-3

1 conversations. The average times spent in these indoor activities and half the time spent in each

2 activity which could have occurred indoors or outdoors (e.g., market work, sports, hobbies, art

3 activities, playing, reading, and other passive leisure) were summed. Table 9-3 summarizes the

4 results of this analysis by age groups and time of the week.

5

6 9.2.2 Robinson and Thomas, 1991

7 Robinson and Thomas (1991) reviewed and compared data from the 1987-88 California

8 Air Resources Board (CARB) time-activity study for California residents and from a similar

9 1985 national study, Americans’ Use of Time. Both studies used the diary approach to collect

10 data. Time- use patterns were collected for individuals aged 12 years and older. Telephone

11 interviews based on the random-digit-dialing procedure were conducted for approximately 1,762

12 and 2,762 respondents for the CARB study and the national study, respectively. 

13 In addition, Robinson and Thomas (1991) defined a set of 16 microenvironments based

14 on the activity and location codes employed in the two studies. The mean duration of time spent

15 in three location categories is presented in Table 9-4. Respondents spent most of their time

16 indoors: 1255 and 1279 min/day for the CARB study and the national study, respectively.

17 Table 9-5 presents the mean duration of time and standard mean error for the

18 16 microenvironments, grouped by total sample population and gender. Also included is the

19 mean time spent for respondents who reported participating in each activity (“doers”). Table 9-5

20 shows that in both studies males spend more time in work locations, in automobiles and other

21 vehicles, in autoplaces (garages), and engaging in physical outdoor activities at outdoor sites. 

22 In contrast, females spend more time cooking, engaging in other kitchen activities, performing

23 other chores, and shopping. The same trends also occurred on a per-participant basis.

24 Table 9-6 shows the mean time spent in various microenvironments by time of week

25 (weekday or weekend) in both studies. Generally, respondents spent most of their time during

26 the weekends in restaurants/bars (CARB study), motor vehicles, outdoor activities,

27 social-cultural settings, leisure/communication activities, and sleeping. Microenvironmental

28 differences by age are presented in Table 9-7.

29 Limitations associated with the Robinson and Thomas (1991) study are that the CARB

30 survey was performed in California only. Therefore, if applied to other populations, the data set

31 may be biased. In addition, the studies were conducted in 1980s and may bias exposure
9-4

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. The available data could not be re-analyzed to conform to the standardized age

4 categories used in this Handbook.

5

6 9.2.3 Wiley et al., 1991

7 The California children's activity pattern survey design (Wiley et al., 1991) provided

8 estimates of the time children spent in various activities and locations (microenvironments) on a

9 typical day. A total of 1,200 children under the age of 12 years were included in the study. The

10 average time spent participating in each of the 10 activity categories is presented in Table 9-8. 

11 Also included in this table are the detailed activity, including its code, with the highest mean

12 duration of time; the percentage of respondents who reported participating in any activity

13 (percent doing); and the mean, median, and maximum time duration for “doers.” The activity

14 category with the highest time expenditure was personal care (794 min/day, or 13.2 hours/day),

15 with night sleep being the detailed activity with the highest average minutes. The activity

16 category “don't know” had a duration of about 2 min/day and only 4% of the respondents

17 reported missing activity time.

18 Table 9-9 presents the mean time spent in the 10 activity categories by age and gender;

19 because the original source data were available, the age categories used by Wiley have been

20 replaced by the standardized age categories used in this Handbook. Differences in activity

21 patterns for boys and girls tended to be small. Table 9-10 presents the mean time spent in the 10

22 activity categories grouped by season and by geographic region. There were seasonal

23 differences for 5 activity categories: personal care, educational activities, social/entertainment,

24 recreation, and communication/ passive leisure. Time expenditure differences in various regions

25 of the state were minimal for childcare, work-related activities, shopping, personal care,

26 education, social life, and recreation.

27 Table 9-11 presents the distribution of time across six location categories. The

28 participation rates (percent) of respondents; the mean, median, and maximum time for "doers;" 

29 and the detailed location with the highest average time expenditure are shown. The largest

30 amount of time spent was at home (1,078 min/day); 99 percent of respondents spent time at

31 home (1,086 min/participant/day). Tables 9-12 and 9-13 show the average time spent in the six
9-5

1 locations grouped by age and gender, and season and region, respectively. Again, because the

2 original source data were available, the age categories used by Wiley have been replaced in

3 Table 9-12 by the standardized age categories used in this Handbook. There are age differences

4 in time expenditure in educational settings (Table 9-12). There are no differences in time

5 expenditure at the six locations by regions, and time spent in school decreased in the summer

6 months compared to other seasons (Table 9-13). 

7 Table 9-14 shows the average potential exposure time children spent in proximity to

8 gasoline fumes and gas oven fumes. The sampled children spent more time closer to gas oven

9 fumes (11 min/day) than to gasoline fumes (2 min/day). Age categories in Table 9-14 have been

10 modified to conform to the standardized categories used in this Handbook. 

11 EPA estimated the total time indoors and outdoors using the data from the Wiley et al.

12 (1991) study. Activities performed indoors, were assumed to include household work, child

13 care, personal needs and care, education, and communication and passive leisure. The average

14 times spent in these indoor activities and half the time spent in each activity which could have

15 occurred either indoors or outdoors (i.e., work-related, goods/services, organizational activities,

16 entertainment/social, don’t know/not coded) were summed. Table 9-15 summarizes the results

17 of this analysis using the standard age groups.

18

19 9.2.4 U.S. EPA, 1992 and U.S. EPA, 2004

20 U.S. EPA (1992) addressed the variables of exposure time, frequency, and duration

21 needed to calculate dermal exposure as related to water and soil contact activities . EPA

22 published updated dermal guidance in 2004 (U.S. EPA, 2004). The reader is referred to these

23 documents for detailed discussion of these variables. The default values for children as

24 presented in U.S. EPA (2004) are summarized in Table 9-16. They were derived from earlier

25 guidance and judgment. The default recommendations are presented as representing children

26 aged 1 to 6 years and cannot be assigned to the standardized age groups (due to lack of more

27 specific supporting data). 

28

29 9.2.5 Tsang and Klepeis, 1996

30 Tsang and Klepeis (1996) analyzed the data collected under The National Human

31 Activity Pattern Survey (NHAPS). This survey was conducted by EPA and is the largest and
9-6

1 most current human activity pattern survey available (Tsang and Klepeis, 1996). A total of

2 9,386 individuals of all ages participated in the study. NHAPS was conducted on a virtually

3 daily basis from late September 1992 through September 1994 by the University of Maryland’s

4 Survey Research Center using a computer-assisted telephone interview instrument (CATI) to

5 collect 24-hour retrospective diaries and answers to a number of personal and exposure related

6 questions from each respondent. Data were collected on duration and frequency of selected

7 activities and of the time spent in selected microenvironments. In addition, demographic

8 information was collected for each respondent to allow for statistical summaries to be generated

9 according to specific subgroups of the U.S. population (e.g., gender, age, race, employment

10 status, census region, season). The participants’ responses were weighted according to

11 geographic, socioeconomic, time/season, and other demographic factors to ensure that results

12 were representative of the U.S. population.

13 Tables 9-17 through 9-56 provide data from the NHAPS study. In most cases, the source

14 data have been reviewed and the analysis done by Tsang and Klepeis has been recast to conform

15 to the age categories used in this Handbook. Because no data were available on subjects’ age in

16 months, age groups less than 1 year old are consolidated into a single group. Tables 9-17 through

17 9-28 present data on the amount of time spent in selected activities and/or the corresponding

18 distribution data, when available.

19

20 C Table 9-17 presents number of showers per day by age of respondents. The data

21 shows that the majority of respondents aged 11 years or older took a shower one or

22 two times a day, while younger children showered less frequently.

23

24 C Table 9-18 shows time spent taking a shower and time spent in the shower room

25 immediately after showering. Most of the respondents spent 10-20 minutes taking a

26 shower and in the shower room after showering.

27

28 C Table 9-19 provides the percentile data for the same activity shown in Table 9-18. 

29 The 50th percentile value is 10 to 15 minutes for showering and 1 to 5 minutes for

30 time spent after showering was complete. The 90th percentile values vary across age

31 groups and range from 30-40 minutes and 10-29 minutes for time spent showering

32 and in the bathroom after showering, respectively.

33

34 C Table 9-20 presents total time (minutes) spent in the shower or bathtub and in the

35 bathroom immediately after a shower or bath. The majority of respondents spent

36 from 10-30 minutes in the shower or bathtub and approximately 10 minutes in the

37 bathroom afterwards.
9-7

1 C Table 9-21 presents the percentile data for the same activity shown in Table 9-20. 

2 The 50th percentile values range from 15-30 minutes and from 2-10 minutes for

3 taking a shower or bath and time spent in the bathroom after the bath, respectively.

4

5 C Table 9-22 provides a range of number of times washing the hands in a day. Most

6 respondents washed their hands 3-5 times a day.

7

8 C Table 9-23 presents statistics data for the number of minutes per day spent working

9 or being near excessive dust in the air. For older children and adolescents, the 50th

10 percentile data indicates that 38 to 60 minutes/day are spent in air with excessive

11 dust.

12

13 C Table 9-24 provides data for the frequency of starting a motor vehicle in a garage or

14 carport and started with the garage door closed.

15

16 C Table 9-25 provides data for the range of minutes/day spent playing on dirt, grass, or

17 sand/gravel.

18

19 C Table 9-26 provides the percentile data for the same activity shown in Table 9-25.

20

21 C Table 9-27 provides the number of times/month swimming in a freshwater swimming

22 pool by number of respondents. The majority of respondents swim in freshwater

23 pools 1 or 2 times/month. A few individuals reported swimming much more

24 frequently (up to 30 or even 60 times per month.)

25

26 C Table 9-28 provides percentile data for the same activity shown in Table 9-27. 

27

28 Tables 9-29 through 9-56 provide statistics for 24-hour cumulative time (minimum,

29 percentiles, and maximum) spent in or in the presence of selected locations or activities. For

30 each location or activity, statistics are calculated for the entire survey population (“Whole

31 Population” and for the subset of the survey population that reported being in or doing the

32 location or activity in question (“Doers Only”). When the sample size was 10 persons or fewer,

33 percentile values were not calculated. Also note that these activities are not necessarily mutually

34 exclusive, e.g. time spent in active sports likely overlaps with exercise time.

35

36 C Table 9-29 provides number of minutes spent sleeping/napping in a day.

37

38 C Table 9-30 presents data for time spent attending full-time school.

39

40 C Table 9-31 provides data for time spent in active sports.

41

42 C Table 9-32 provides time spent on exercise.

43
9-8

1 C Table 9-33 presents data for time spent in outdoor recreation.

2

3 C Table 9-34 provides data for time spent walking.

4

5 C Table 9-35 provides data for time spent bathing.

6

7 C Table 9-36 presents statistics for minutes eating.

8

9 C Table 9-37 provides data for time spent indoors at a restaurant.

10

11 C Table 9-38 provides data for time spent indoors at school.

12

13 C Table 9-39 provides information for time spent outdoors on school

14 grounds/playgrounds, at parks or golf courses, and at pools/rivers/lakes.

15

16 C Table 9-40 provides information on time spent at home in the kitchen.

17

18 C Table 9-41 provides information on time spent at home in the living room, family

19 room, or den.

20

21 C Table 9-42 provides information on time spent at home in the dining room.

22

23 C Table 9-43 provides information on time spent at home in the bathroom.

24

25 C Table 9-44 provides information on time spent at home in the bedroom.

26

27 C Table 9-45 provides information on time spent at home in the study or office.

28

29 C Table 9-46 provides information on time spent at home in the garage.

30

31 C Table 9-47 provides information on time spent at home in the utility room or laundry

32 room.

33

34 C Table 9-48 provides information on time spent in a car.

35

36 C Table 9-49 provides information on time spent in a truck (pickup or van).

37

38 C Table 9-50 provides information on time spent in a truck (not a pickup or van).

39

40 C Table 9-51 provides information on time spent on a bus.

41

42 C Table 9-52 provides information on time spent on a train.

43

44 C Table 9-53 provides information on time spent on an airplane.

45

46 C Table 9-54 provides information on time spent on a boat.
9-9

1 C Table 9-55 provides information on the total time spent in vehicles.

2

3 C Table 9-56 provides information on time spent in grocery/convenience stores, other

4 stores, and malls.

5

6 C Table 9-57 provides data on time spent in indoor and outdoor environments.

7

8 C Table 9-58 provides information on time spent in the presence of smokers. For this

9 data set, the authors’ original age categories were used because the methodology used

10 to generate the data could not be reproduced.

11

12 Advantages of the NHAPS data set 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 inclusive of all ages, genders, and races. A disadvantage of the study is that for the standard age

15 categories, “N” is small for the “doers” of many activities. In addition, means cannot be

16 calculated for time spent over 60, 120, and 181 minutes in selected activities. Therefore, actual

17 time spent at the high end of the distribution for these activities cannot be assessed with

18 accuracy.

19

20 9.2.6 Funk et al., 1998

21 Funk et al. (1998) used the data from the California Air Resources Board (CARB) study

22 to determine distributions of exposure time by tracking the time spent participating in daily at23 home and at-school activities for male and female children and adolescents. CARB performed

24 two studies from 1987 to 1990; the first was focused on adults (18 years and older) and

25 adolescents (12-17 years old), and the second focused on children (6-11 years old) (Funk et al.,

26 1998). The targeted groups were noninstitutionalized English speaking Californians with a

27 telephone in their residence. Individuals were contacted by telephone and asked to account for

28 every minute within the previous 24 hours, including the amount of time spent on an activity and

29 the location of the activity. The surveys were conducted on different days of the week as well as

30 different seasons of the year.

31 Using the location descriptors provided in the CARB study, Funk et al. (1998)

32 categorized the activities into two groups, “at home” (any activity at principal residence) and

33 “away.” Each activity was assigned to one of three ventilation levels (low, moderate, or high)

34 based on the level of exertion expected from the activity. Ambiguous activities were assigned to
9-10

1 moderate ventilation levels. Among the adolescents and children studied, means were

2 determined for the aggregate age groups, as shown in Table 9-59.

3 Funk et al. used several statistical methods, such as Chi-square, Kolmogorov-Smirnov,

4 and Anderson-Darling, to determine whether the time spent in an activity group had a known

5 distribution. Most of the activities performed by children were assigned a low or moderate

6 ventilation rate (Table 9-60).

7 The aggregate time periods spent at home in each activity are shown in Table 9-61.

8 Aggregate time spent at home performing different activities was compared between genders. 

9 There were no significant differences between adolescent male and females in any of the activity

10 groups (Funk et al., 1998) (Table 9-62). In children ages 6-11 years there were differences

11 found between gender and age at the low ventilation levels. In the moderate ventilation level

12 there were significant differences between two age groups (6-8 years, and 9-11 years) and

13 gender (Funk et al., 1998) (Table 9-63).

14 Large proportions of the respondents in the study did not participate in high-ventilation15 level activities; discrete distributions were used to characterize high ventilation activity groups

16 (Funk et al., 1998). Lognormal distribution best described the time spent by children at high

17 ventilation levels.

18

19 9.2.7 Hubal et al., 2000

20 Hubal et al. (2000) reviewed available data, including activity pattern data, to

21 characterize and assess environmental exposures to children. The EPA National Exposure

22 Research Laboratory’s Consolidated Human Activity Database (CHAD), which contained data

23 from several studies on human activities, was reviewed. For children and adolescents younger

24 than 18 years, CHAD contained 4,300 person-days of information and 3,009 person-days of 

25 macroactivity data for 2,640 children less than 12 years old (Hubal et al., 2000) (Table 9-64). 

26 Specific examples of the type of macroactivity data available in CHAD for children are shown

27 in Tables 9-65 and 9-66. The number of hours spent in various microenvironments are shown in

28 Table 9-65 and time spent in various activities indoors at home in Table 9-66.

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

31 respondent. In fact, not all of the codes were used for most of the studies. Even though many
9-11

1 codes are used in macroactivity studies, many of the activity codes do not adequately capture the

2 richness of what children actually do. They are much too broadly defined and ignore many

3 child-oriented behaviors. Thus, there is a need for more and better-focused research into

4 children’s activities.” CHAD is available on the EPA Internet at: 

5 http://www.epa.gov/chadnet1/.

6 EPA has performed an analysis of the source data used by Hubal et al. (2000) to recast

7 the study’s results using CHAD data downloaded in 2000 and the new standard age categories.

8 The results are shown in Tables 9-67 and 9-68. In this analysis, individual study participants

9 within CHAD whose behavior patterns were measured over multiple days were treated as

10 multiple one-day activity patterns. This is a potential source of error or bias in the results

11 because a single individual may contribute multiple data sets to the aggregate population being

12 studied.

13

14 9.2.8 Wong et al., 2000

15 Wong et al. (2000) conducted telephone surveys to gather information on children’s

16 activity patterns as related to dermal contact with soil during outdoor play on bare dirt or mixed

17 grass and dirt surfaces. This study, the second Soil Contact Survey (SCS-II), was a follow-up to

18 the initial Soil Contact Survey (SCS-I), conducted in 1996, that primarily focused on assessing

19 adult behavior related to dermal contact with soil and dust (Garlock et al., 1999). As part of

20 SCS-I, information was gathered on the behavior of children under the age of 18 years, however,

21 the questions were limited to clothing choices and the length of time after soil contact to hand

22 washing. Questions were posed for SCS-II to further define children’s outdoor activities and

23 hand washing and bathing frequency. For both soil contact surveys households were randomly

24 phoned in order to obtain nationally representative results. The adult respondents were

25 questioned as surrogates for one randomly chosen child under the age of 18 residing within the

26 household.

27 In the SCS-II, of 680 total adult respondents with a child in their household, 500 (73.5%)

28 reported that their child played outdoors on bare dirt or mixed grass and dirt surfaces (identified

29 as “players”). Those children that reportedly did not play outdoors (“non-players”) were

30 typically very young (#1 year) or relatively older ($14 years). Of the 500 children that played

31 outdoors, 497 played outdoors in warm weather months (April through October) and 390 were
9-12

1 reported to play outdoors during cold weather months (November through March). These results

2 are presented in Table 9-69. The frequency (days/week), duration (hours/day), and total hours

3 per week spent playing outdoors was determined for those children identified as “players”

4 (Table 9-70). The responses indicated that during the warmer months children spend a relatively

5 high percentage of time outdoor and a lesser amount of time in cold weather. The median play

6 frequency reported was 7 days/week in warm weather and 3 days/week in cold weather. Median

7 play duration was 3 hours/day in warm weather and 1 hour/day during cold weather months.

8 Adult respondents were then questioned as to how many times per day their child washed

9 his/her hands and how many times the child bathed or showered per week during both warm and

10 cold weather months. This information provided an estimate of the time between skin contact

11 with soil and removal of soil by washing (i.e., exposure time). Hand washing and bathing

12 frequencies for child players are reported in Table 9-71. Based on these results, hand washing

13 occurred a median of 4 times per day during both warm and cold weather months. The median

14 frequency for baths and showers was estimated to be 7 times per week for both warm and cold

15 weather.

16 Based on reported household incomes, the respondents sampled in SCS-II tended to have

17 higher incomes than that of the general population. This may be explained by the fact that phone

18 surveys cannot sample those households without telephones. Additional uncertainty or error in

19 the study results may be presented by the use of surrogate respondents. Adult respondents were

20 questioned regarding child activities that may have occurred in prior seasons, introducing the

21 chance of recall error. In some instances, a respondent did not know the answer to a question or

22 refused to answer. In Tables 9-72 and 9-73 information were extracted from the National

23 Human Activity Pattern Survey (NHAPS) (U.S. EPA, 1996). Table 9-72 compares mean play

24 duration data from SCS-II to similar activities identified in NHAPS. The number of times per

25 day a child washed his or her hands was presented in both SCS-II and NHAPS follow-up survey

26 B and are shown in Table 9-73. Corresponding information for bathing frequency data collected

27 from SCS-II was not collected in NHAPS. As indicated in Tables 9-72 and 9-73, where

28 comparison is possible, NHAPS and SCS-II results showed similarities in observed behaviors.

29

30 9.2.9. Graham and McCurdy, 2004

31
9-13

1 This paper uses analyses of CHAD to evaluate how cohort definitions can affect statistics

2 on activity patterns. Age and gender are typically used as the primary cohort-defining attributes,

3 but more complex exposure models also use weather, day-of-the-week, and employment

4 attributes for this purpose. All of these attributes and others were evaluated to determine if

5 statistically significant differences exist among them to warrant their being used to define

6 distinct cohort groups. The analysis focused mostly on the relationship between cohort attributes

7 and the time spent outdoors, indoors, and in motor vehicles. The results indicate that besides age

8 and gender, other important attributes for defining cohorts are the physical activity level of

9 individuals, whether factors such as daily maximum temperature in combination with months of

10 the year, and combined weekday/weekend with employment status. Less important are

11 precipitation and ethnic data. While statistically significant, the collective set of attributes does

12 not explain a large amount of variance in outdoor, indoor, or in-vehicle locational decisions.

13 Based on other research, parameters such as lifestyle and life stages that are absent from CHAD

14 might have reduced the amount of unexplained variance. The authors recommend that exposure

15 modelers use age and gender as ‘‘first-order’’ attributes to define cohorts followed by physical

16 activity level, daily maximum temperature or other suitable weather parameters, and day type

17 possibly beyond a simple weekday/weekend classification.

18

19 9.3 RECOMMENDATIONS

20 Assessors are commonly interested in a number of specific types of time use data for

21 children including times for bathing, showering, indoor activity, outdoor activity, swimming, and

22 surface type during play. The studies used to develop recommendations for these factors are

23 summarized in Tables 9-74 and 9-75. The recommended values for the factors are discussed

24 below and summarized in Table 9-76. Only means or medians were provided because these are

based on short term data and 95th 25 percentiles would be potentially misleading for long term

26 estimates. The confidence in the recommendations for activity patterns is presented in Table 9-

27 77. 

28 Time Spent Indoors and Outdoors - Assessors often require knowledge of time

29 individuals spend indoors versus outdoors. Ideally, this issue would be addressed on a site30 specific basis since the times are likely to vary considerably depending on the climate,

31 residential setting (i.e., rural versus urban), personal traits (i.e., age, health) and personal habits. 
9-14

1 Activities can vary significantly with differences in age. Table 9-75 summarizes the studies that

2 present information on time indoors and outdoors. Of these studies, the Wiley et al. (1991) and

3 Tsang and Kleipeis (1996) studies were most conducive to being recast to fit the standardized

4 age categories in this Handbook. The recommended values are presented in Table 9-76 for the

5 standardized age groups,. The recommendations for time spent indoors at a residence are based

6 on the EPA re-analysis of the Tsang and Kleipeis (1996). The recommendations for total time

7 spent indoors are based on the EPA re-analysis of the Tsang and Kleipeis (1996) and Wiley et al.

8 (1991) data. The recommendations for total time spent outdoors are based on the EPA re9 analysis of the Tsang and Kleipeis (1996) and Wiley et al. (1991) data. 

10 Showering and Bathing - The recommended values for shower and bath duration are

11 presented in Table 9-76 for the standardized age groups, based on the EPA re-analysis of the

12 Tsang and Kleipeis (1996). 

13 Swimming - The recommended values for swimming time are presented in Table 9-76

14 for the standardized age groups, based on the EPA re-analysis of the Tsang and Kleipeis (1996). 

15 Playing on Sand or Gravel, on Grass, and on Dirt - The recommended values for time

16 spent playing on sand, gravel, grass or dirt are presented in Table 9-76 based on the EPA re17 analysis of the Tsang and Kleipeis (1996). . 

18

19
9-15

1 9.4 REFERENCES FOR CHAPTER 9

2

3 Chance, W.G.; Harmsen, E. (1998) Children are different: environmental contaminants and children’s health. 

4 Canadian Journal of Public Health, Vol. 89, Supplement. pp. 59-513.

5

6 Funk, L.; Sedman, R.; Beals, J.A.J.; Fountain, R. (1998) Quantifying the distribution of inhalation exposure in

7 human populations: distributions of time spent by adults, adolescents, and children at home, at work, and at

8 school. Risk Analysis. 18(1):47-56.

9

10 Graham, SE and McCurdy, T (2004). Developing meaningful cohorts for human exposure models. J Expo Anal

11 Environ Epidemiol. 14:23-43. 

12

13 Hubal, E.A.; Sheldon, L.S.; Burke, J.M.; McCurdy, T.R.; Berry, M.R.; Rigas, M.L.; Zartarian, V.G.; Freeman, N.G. 

14 (2000) Children’s exposure assessment: a review of factors influencing children’s exposure and the data available

15 to characterize and assess that exposure. Environ. Health Persp. 108:475-485.

16

17 Robinson, J.P; Thomas, J. (1991) Time spent in activities, locations, and microenvironments: a California-National

18 Comparison Project report. Las Vegas, NV: U.S. Environmental Protection Agency, Environmental Monitoring

19 Systems Laboratory.

20

21 Timmer, S.G.; Eccles, J.; O'Brien, K. (1985) How children use time. In: Juster, F.T.; Stafford, F.P.; eds. Time,

22 goods, and well-being. Ann Arbor, MI: University of Michigan, Survey Research Center, Institute for Social

23 Research, pp. 353-380.

24

25 Tsang, A.M.; Klepeis, N.E. (1996) Results tables from a detailed analysis of the National Human Activity Pattern

26 Survey (NHAPS) response. Draft Report prepared for the U.S. Environmental Protection Agency by Lockheed

27 Martin, Contract No. 68-W6-001, Delivery Order No. 13.

28

29 U.S. EPA. (1992) Dermal exposure assessment: principles and applications. Washington, DC: Office of Health

30 and Environmental Assessment. EPA No. 600/8-91-011B. Interim Report.

31

32 U.S. EPA. (1997) Exposure Factors Handbook. Washington, DC: National Center for Environmental Assessment,

33 Office of Research and Development. EPA/600/P-95/002Fa,b,c.

34

35 U.S. EPA. (2004) Risk Assessment Guidance for Superfund Volume I: Human Health Evaluation Manual (Part E,

36 Supplemental Guidance for Dermal Risk Assessment). EPA/540/R/99/005. 

37 http://www.epa.gov/superfund/programs/risk/ragse/index.htm

38

39 Wiley, J.A.; Robinson, J.P.; Cheng, Y.; Piazza, T.; Stork, L.; Plasden, K. (1991) Study of children’s activity

40 patterns. California Environmental Protection Agency, Air Resources Board Research Division. Sacramento,

41 CA.

42

43 Wong E. Y., Shirai, J.H, Garlock, T. J., and Kissel, J.C. (2000) Adult proxy responses to a survey of children’s

44 dermal soil contact activities. J Expo Anal Environ Epidemiol. 10:509-517.

45
9-16

Table 9-1. Mean Time Spent (minutes) Performing Major Activities Grouped by Age, Sex and Type of Day

Activity

Age (3-11 years) Age (12-17 years)

Duration of Time (mins/day) Duration of Time (mins/day)

Weekdays Weekends Weekdays Weekends

Boys

(n=118)

Girls

(n=111)

Boys

(n=118)

Girls

(n=111)

Boys

(n=77)

Girls

(n=83)

Boys

(n=77)

Girls

(n=83)

Market Work 16 0 7 4 23 21 58 25

Household Work 17 21 32 43 16 40 46 89

Personal Care 43 44 42 50 48 71 35 76

Eating 81 78 78 84 73 65 58 75

Sleeping 584 590 625 619 504 478 550 612

School 252 259 -- -- 314 342 -- --

Studying 14 19 4 9 29 37 25 25

Church 7 4 53 61 3 7 40 36

Visiting 16 9 23 37 17 25 46 53

Sports 25 12 33 23 52 37 65 26

Outdoors 10 7 30 23 10 10 36 19

Hobbies 31347447

Art Activities 4 4 4 4 12 6 11 9

Playing 137 115 177 166 37 13 35 24

TV 117 128 181 122 143 108 187 140

Reading 9 7 12 10 10 13 12 19

Household Conversations 10 11 14 9 21 30 24 30

Other Passive Leisure 9 14 16 17 21 14 43 33

NAa 22 25 20 29 14 17 10 4

Percent of Time Accounted for

by Activities Above

94% 92% 93% 89% 93% 92% 88% 89%

a NA = Unknown

Source: Timmer et al., 1985.
9-17

Table 9-2. Mean Time Spent (minutes) in Major Activities Grouped by Type of Day for Five Different Age Groups

Activity

Time Duration (mins)

Significant

Effectsa

Weekday Weekend

Age Groups Age Groups

3-5 6-8 9-11 12-14 15-17 3-5 6-8 9-11 12-14 15-17

Market Work -- 14 8 14 28 -- 4 10 29 48

Personal Care 41 49 40 56 60 47 45 44 60 51 A,S,AxS (F>M)

Household Work 14 15 18 27 34 17 27 51 72 60 A,S, AxS (F>M)

Eating 82 81 73 69 67 81 80 78 68 65 A

Sleeping 630 595 548 473 499 634 641 596 604 562 A

School 137 292 315 344 314 -- -- -- -- --

Studying 2 8 29 33 33 1 2 12 15 30 A

Church 4 9 9 9 3 55 56 53 32 37 A

Visiting 14 15 10 21 20 10 8 13 22 56 A (Weekend only)

Sports 5 24 21 40 46 3 30 42 51 37 A,S (M>F)

Outdoor activities 4 9 8 7 11 8 23 39 25 26

Hobbies 0 2 2 4 6 1 5 3 8 3

Art Activities 5 4 3 3 12 4 4 4 7 10

Other Passive Leisure 9 1 2 6 4 6 10 7 10 18 A

Playing 218 111 65 31 14 267 180 92 35 21 A,S (M>F)

TV 111 99 146 142 108 122 136 185 169 157 A,S, AxS (M>F)

Reading 5 5 9 10 12 4 9 10 10 18 A

Being read to 2 2 0 0 0 3 2 0 0 0 A

NA 30 14 23 25 7 52 7 14 4 9 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 = age by sex interaction, P<0.05.

Source: Timmer et al., 1985.
9-18

Table 9-3. Mean Time Spent Indoors and Outdoors Grouped by Age and Day of the Week

Age Group

(yrs)

Time Indoors

Weekday

(hrs/day)

Time Indoors

Weekend

(hrs/day)

Time Outdoors

Weekday

(hrs/day)

Time Outdoors

Weekend

(hrs/day)

3-5 19.4 18.9 2.5 3.1

6-8 20.7 18.6 1.8 2.5

9-11 20.8 18.6 1.3 2.3

12-14 20.7 18.5 1.6 1.9

15-17 19.9 17.9 1.4 2.3

Source: Adapted from Timmer et al. (1985).
9-19

Table 9-4. Mean Time Spent at Three Locations for both CARB and National Studies (ages 12 years and older)

Location Category

Mean duration (mins/day)

CARB

(n = 1762)b S.E.a

National

(n = 2762)b S.E.

Indoor 1255c 28 1279c 21

Outdoor 86d 5 74d 4

In-Vehicle 98d 4 87d 2

Total Time Spent 1440 1440

a

 S.E. = Standard Error of Mean

b Weighted Number - National sample population was weighted to obtain a ratio of 46.5 males and 53.5 females, in equal

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. d Difference between the mean values for the CARB and national studies is statistically significant at the 0.05 level.

Source: Robinson and Thomas, 1991.
9-20

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 CARB Data

Microenvironment

National Data

Mean Duration (mins/day) (standard error)a

N = 1284b

Male

"Doer"c

Male

N = 1478b

Female

"Doer"

Female

N = 2762b

Total

"Doer"

Total

Autoplaces 5 (1) 90 1 (0) 35 3 (0) 66

Restaurant/bar 22 (2) 73 20 (2) 79 21 (1) 77

In-vehicle 92 (3) 99 82 (3) 94 87 (2) 97

In-Vehicle/other 1 (1) 166 1 (0) 69 1 (0) 91

Physical/outdoors 24 (3) 139 11 (2) 101 17 (2) 135

Physical/indoors 11 (1) 84 6 (1) 57 8 (1) 74

Work/study-residence 17 (2) 153 15 (2) 150 16 (1) 142

Work/study-other 221 (10) 429 142 (7) 384 179 (6) 390

Cooking 14 (1) 35 52 (2) 67 34 (1) 57

Other activities/kitchen 54 (3) 69 90 (4) 102 73 (2) 88

Chores/child 88 (3) 89 153 (5) 154 123 93) 124

Shop/errand 23 (2) 56 38 (2) 74 31 (1) 67

Other/outdoors 70 (6) 131 43 (4) 97 56 (4) 120

Social/cultural 71 (4) 118 75 (4) 110 73 (3) 118

Leisure-eat/indoors 235 (8) 241 215 (7) 224 224 (5) 232

Sleep/indoors 491 (14) 492 496 (11) 497 494 (9) 495

Microenvironment

CARB Data

Mean Duration (mins/day) (standard error)a

N = 867b

Male

"Doer"c

Male

N = 895b

Female

"Doer"

Female

N = 1762b

Total

"Doer"

Total

Autoplaces 31 (8) 142 9 (2) 50 20 (4) 108

Restaurant/bar 45 (4) 106 28 (3) 86 36 (3) 102

In-vehicle 105 (7) 119 85 (4) 100 95 (4) 111

In-Vehicle/other 4 (1) 79 3 (2) 106 3 (1) 94

Physical/outdoors 25 (3) 131 8 (1) 86 17 (2) 107

Physical/indoors 8 (1) 63 5 (1) 70 7 (1) 68

Work/study-residence 14 (3) 126 11 (2) 120 13 (2) 131

Work/study-other 213 (14) 398 156 (11) 383 184 (9) 450

Cooking 12 (1) 43 42 (2) 65 27 (1) 55

Other activities/kitchen 38 (3) 65 60 (4) 82 49 (2) 74

Chores/child 66 (4) 75 134 (6) 140 100 (4) 109

Shop/errand 21 (3) 61 41 (3) 78 31 (2) 70

Other/outdoors 95 (9) 153 44 (4) 82 69 (5) 117

Social/cultural 47 (4) 112 59 (5) 114 53 (3) 112

Leisure-eat/indoors 223 (10) 240 251 (10) 263 237 (7) 250

Sleep/indoors 492 (17) 499 504 (15) 506 498 (12) 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.
9-21

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

Mean Duration (standard error)a

(mins/day)

Mean Duration for "Doer"b

(mins/day)

CARB

(n=1259)c

NAT

(n=1973)c CARB NAT

 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

11 Chores/Child

12 Shop/Errand

13 Other/Outdoors

14 Social/Cultural

15 Leisure-Eat/Indoors

16 Sleep/Indoors

21 (5)

29 (3)

90 (5)

3 (1)

14 (2)

7 (1)

14 (2)

228 (11)

27 (2)

51 (3)

99 (5)

30 (2)

67 (6)

42 (3)

230 (9)

490 (14)

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)

108

83

104

71

106

64

116

401

58

76

108

67

117

99

244

495

73

73

95

116

118

68

147

415

57

87

125

63

107

101

218

483

Weekend

Microenvironment

Mean Duration (standard error)a

(mins/day)

Mean Duration for "Doer"b

(mins/day)

CARB

(n=503)c

NAT

(n=789)c CARB NAT

 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

11 Chores/Child

12 Shop/Errand

13 Other/Outdoors

14 Social/Cultural

15 Leisure-Eat/Indoors

16 Sleep/Indoors

19 (4)

55 (6)

108 (8)

5 (3)

23 (3)

7 (1)

10 (2)

74 (11)

27 (2)

44 (3)

103 (7)

35 (4)

74 (7)

79 (7)

256 (12)

520 (20)

3 (1)

23 (2)

91 (6)

0 (0)

23 (4)

9 (2)

15 (3)

64 (6)

34 (2)

73 (4)

120 (5)

35 (3)

67 (7)

99 (6)

257 (11)

525 (17)

82

127

125

130

134

72

155

328

60

71

114

81

126

140

273

521

62

84

100

30

132

80

165

361

55

90

121

75

132

141

268

525

a

 Standard Error of Mean

b

 Doer = Respondent who reported participating in each activity/location spent in microenvironments. c

 Weighted Number

Source: Robinson and Thomas, 1991.
9-22

Table 9-7. Mean Time Spent (minutes/day) in Various Microenvironments by Age Groups for the National and

California Surveys

Microenvironment

National Data

Mean Duration (Standard Error)a

Age 12-17 years

N=340b "Doer"c

Age 18-24 years

N=340 "Doer"

Autoplaces 2 (1) 73 7 (2) 137

Restaurant/bar 9 (2) 60 28 (3) 70

In-vehicle/internal combustion 79 (7) 88 103 (8) 109

In-vehicle/other 0 (0) 12 1 (1) 160

Physical/outdoors 32 (8) 130 17 (4) 110

Physical/indoors 15 (3) 87 8 (2) 76

Work/study-residence 22 (4) 82 19 (6) 185

Work/study-other 159 (14) 354 207 (20) 391

Cooking 11 (3) 40 18 (2) 39

Other activities/kitchen 53 (4) 64 42 (3) 55

Chores/child 91 (7) 92 124 (9) 125

Shop/errands 26 (4) 68 31 (4) 65

Other/outdoors 70 (13) 129 34 (4) 84

Social/cultural 87 (10) 120 100 (12) 141

Leisure-eat/indoors 237 (16) 242 181 (11) 189

Sleep/indoors 548 (31) 551 511 (26) 512

Microenvironment

CARB Data

Mean Duration (Standard Error)a

Age 12-17 years

N=183b "Doer"c

Age 18-24 years

N=250 "Doer"

Autoplaces 16 (8) 124 16 (4) 71

Restaurant/bar 16 (4) 44 40 (8) 98

In-vehicle/internal combustion 78 (11) 89 111 (13) 122

In-vehicle/other 1 (0) 19 3 (1) 60

Physical/outdoors 32 (7) 110 13 (3) 88

Physical/indoors 20 (4) 65 5 (2) 77

Work/study-residence 25 (5) 76 30 (11) 161

Work/study-other 196 (30) 339 201 (24) 344

Cooking 3 (1) 19 14 (2) 40

Other activities/kitchen 31 (4) 51 31 (5) 55

Chores/child 72 (11) 77 79 (8) 85

Shop/errands 14 (3) 50 35 (7) 71

Other/outdoors 58 (8) 78 80 (15) 130

Social/cultural 63 (14) 109 65 (10) 110

Leisure-eat/indoors 260 (27) 270 211 (19) 234

Sleep/indoors 557 (44) 560 506 (30) 510

a Standard error. b All N’s are weighted number. c Doer = Respondents who reported participating in each activity/location spent in microenvironments.

Source: Robinson and Thomas, 1991.
9-23

Table 9-8. Mean Time (minutes/day) Children Ages 12 Years and Under Spent in Ten Major Activity Categories for

All Respondents

Activity Category

Mean

Duration

(mins/day)

%

Doing

Mean

Duration

for Doersb

(mins/day)

Median

Duration

for Doer

(mins/day)

Maximum 

Duration

for Doers

(mins/day)

Detailed Activity with

Highest Avg. Minutes

(code)

Work-relateda 10 25 39 30 405 Eating at work/school/daycare (06)

Household 53 86 61 40 602 Travel to household (199)

Childcare < 1 < 1 83 30 290 Other child care (27)

Goods/Services 21 26 81 60 450 Errands (38)

Personal Needs and Carec 794 100 794 770 1440 Night sleep (45)

Educationd 110 35 316 335 790 School classes (50)

Organizational Activities 4 4 111 105 435 Attend meetings (60)

Entertain/Social 15 17 87 60 490 Visiting with others (75)

Recreation 239 92 260 240 835 Games (87)

Communication/Passive

Leisure

192 93 205 180 898 TV use (91)

Don't know/Not coded 2 4 41 15 600 --

All Activitiese 1441

a

 Includes eating at school or daycare, an activity not grouped under the "education activities" (codes 50-59, 549). b

 "Doers" indicate the respondents who reported participating in each activity category. c

 Personal care includes night sleep and daytime naps, eating, travel for personal care. d

 Education includes student and other classes, homework, library, travel for education. e

 Column total may not sum to 1440 due to rounding error

Source: Wiley et al., 1991.
9-24

Table 9-9. Mean Time Children Spent in Ten Major Activity Categories by Age and Gender

Activity

Category

Mean Duration (minutes/day) - BOYS

birth

to 1

month

1 to <3

months

3 to <6

months

6 to

<12

months

1 to <2

years

2 to <3

years

3 to <6

years

6 to

<11

years

11

yearsd

0-11

yrs

Work-related 0 0 0 1 8 9 10 12 13 11

Household 12 30 49 28 35 44 44 61 63 58

Childcare 0 0 0 0 0 0 0 0 3 2

Goods/Services 0 16 14 28 27 14 28 22 24 26

Personal Needs and Carea 910 1143 937 919 903 889 802 726 707 802

Educationb 180c 0 75 70 33 69 67 120 120 100

Organizational Activities 0 0 0 0 7 0 5 11 16 6

Entertainment/Social 0 0 0 0 8 6 15 15 43 18

Recreation 0 0 26 104 314 304 294 265 227 228

Communication/Passive

Leisure

338 250 339 292 106 103 175 208 226 226

Sample Sizes

(Unweighted)

3 7 15 31 54 62 151 239 62 624

Activity

Category

Mean Duration (minutes/day) - GIRLS

birth

to 1

month

1 to <3

months

3 to <6

months

6 to

<12

months

1 to <2

years

2 to <3

years

3 to <6

years

6 to

<11

years

11

yearsd

0-11

yrs

Work-related 0 0 5 1 3 22 9 10 19 11

Household 28 29 23 25 45 65 49 67 78 58

Childcare 0 0 0 0 0 0 0 2 9 2

Goods/Services 0 18 14 24 24 34 31 26 15 26

Personal Needs and Carea 1123 1115 971 922 894 858 820 747 703 802

Educationb 0 0 110 94 25 40 81 134 151 100

Organizational Activities 0 0 0 0 0 2 3 8 13 6

Entertainment/Social 0 0 0 1 13 6 16 17 52 18

Recreation 0 0 10 147 256 305 270 224 175 228

Communication/Passive

Leisure

290 278 308 226 179 107 161 203 225 189

Sample Sizes

(Unweighted)

4 10 11 23 43 50 151 225 59 576

a

 Personal needs and care includes night sleep and daytime naps, eating, travel for personal care. b

 Education includes student and other classes, homework, library, travel for education. c

The data for this age group and category are two values of zero and one of 540. d

The source data end at 11 years of age, so the 11 to <16 year category is truncated and the 16 to <21 year category is not included.

Source: EPA Analysis of source data used by Wiley et al . (1991).
9-25

Table 9-10. Mean Time Children Ages 12 Years and Under Spent in Ten Major Activity Categories Grouped by

Seasons and Regions

Activity Category

Mean Duration (minutes/day)

Season Region of California

Winter

(Jan-Mar)

Spring

(Apr-June)

Summer

(July-Sept)

Fall

(Oct-Dec)

All

Seasons

So.

Coast

Bay

Area

Rest of

State

All

Regions

Work-related 10 10 6 13 10 10 10 8 10

Household 47 58 53 52 53 45 62 55 53

Childcare <1 1 <1 <1 <1 <1 <1 1 <1

Goods/Services 19 17 26 23 21 20 21 23 21

Personal Needs and

Carea

799 774 815 789 794 799 785 794 794

Educationb 124 137 49 131 110 109 115 109 110

Organizational

Activities

3 5 5 3 42 6 6 4

Entertainment/Social 14 12 12 22 15 17 10 16 15

Recreation 221 243 282 211 239 230 241 249 239

Communication/Pass

ive Leisure

203 180 189 195 192 206 190 175 192

Don't know/Not

coded

<1 2 3 <1 2 1 1 3 2

All Activitiesc 1442 1439 1441 1441 1441 1440 1442 1439 1441

Sample Sizes

(Unweighted)

318 204 407 271 1200 224 263 713 1200

a

 Personal needs and care includes night sleep and daytime naps, eating, travel for personal care. b

 Education includes student and other classes, homework, library, travel for education. c

 The column totals may not be equal to 1440 due to rounding error.

Source: Wiley et al., 1991.
9-26

Table 9-11. Mean Time Children Ages 12 Years and Under Spent in Six Major Location Categories for All

Respondents (minutes/day)

Location Category

Mean

Duration

(min)

%

Doing

Mean

Duration

for Doers

(min)

Median

Duration

for Doers

(min)

Maximum

Duration for

Doers

(min)

Detailed Location with Highest

Avg. Time

Home 1,078 99 1,086 1,110 1,440 Home - bedroom

School/Childcare 109 33 330 325 1,260 School or daycare facility

Friend's/Other's House 80 32 251 144 1,440 Friend's/other's house - bedroom

Stores, Restaurants,

Shopping Places

24 35 69 50 475 Shopping mall

In-transit 69 83 83 60 1,111 Traveling in car

Other Locations 79 57 139 105 1,440 Park, playground

Don't Know/Not Coded <1 1 37 30 90 --

All Locations 1,440

Source: Wiley et al., 1991.
9-27

Table 9-12. Mean Time Children Spent in Six Location Categories Grouped by Age and Gender

Location Category

Mean Duration (minutes/day) - BOYS

birth

to 1

month

1 to <3

months

3 to <6

months

6 to <12

months

1 to <2

years

2 to <3

years

3 to <6

years

6 to <11

years

11 yearsa 0-11

yrs

Home 938 1295 1164 1189 1177 1161 1102 1016 1010 1079

School/Childcare 0 1 26 53 73 86 79 110 99 89

Friend's/Other's House 418 40 127 63 54 69 89 110 111 95

Stores, Restaurants,

Shopping Places

0 14 21 36 29 22 24 23 20 24

In-transit 77 51 69 63 56 61 67 64 72 65

Other Locations 7 40 33 36 52 41 78 116 127 88

Don't Know/Not Coded 0 0 0 0 0 0 0 0 0 0

Sample Sizes

(Unweighted)

3 7 15 31 54 62 151 239 62 624

Location Category

Mean Duration (minutes/day) - GIRLS

birth

to 1

month

1 to <3

months

3 to <6

months

6 to <12

months

1 to <2

years

2 to <3

years

3 to <6

years

6 to <11

years

11 yearsb 0-11

yrs

Home 1285 1341 1151 1192 1162 1065 1118 1012 862 1058

School/Childcare 0 0 109 99 56 61 78 116 128 95

Friend's/Other's House 0 12 44 32 109 103 66 119 193 103

Stores, Restaurants,

Shopping Places

0 13 20 15 21 40 32 25 24 27

In-transit 73 56 42 58 55 86 78 70 95 74

Other Locations 83 19 73 43 38 86 67 97 137 84

Don't Know/Not Coded 0 0 0 0 0 0 1 0 0 0

Sample Sizes

(Unweighted)

4 10 11 23 43 50 151 225 59 576

a The source data end at 11 years of age, so the 11 to <16 year category is truncated and the 16 to <21 year category is not included.

Source: EPA Analysis of source data used by Wiley et al . (1991).
9-28

Table 9-13. Mean Time Children Spent in Six Location Categories Grouped by Season and Region

Location Category

Mean Duration (minutes/day)

Season Region of California

Winter

(Jan-Mar)

Spring

(Apr-June)

Summer

(July-Sept)

Fall

(Oct-Dec)

All

Seasons

So.

Coast

Bay

Area

Rest of

State

All

Regions

Home 1,091 1,042 1,097 1,081 1,078 1,078 1,078 1,078 1,078

School/Childcare 119 141 52 124 109 113 103 108 109

Friend's/Other's House 69 75 108 69 80 73 86 86 80

Stores, Restaurants,

Shopping Places

22 21 30 24 24 26 23 23 24

In transit 75 75 60 65 69 71 73 63 69

Other Locations 63 85 93 76 79 79 76 81 79

Don't Know/Not

Coded

<1 <1 <1 <1 <1 <1 <1 <1 <1

All Locationsa 1,439 1,439 1,440 1,439 1,439 1,439 1,440 1,440 1,439

Sample Sizes

(Unweighted N's)

318 204 407 271 1,200 224 263 713 1,200

a

 The column totals may not sum to 1,440 due to rounding error.

Source: Wiley et al., 1991.
9-29

Table 9-14. Mean Time Children Spent in Proximity to Two Potential Exposures Grouped by All Respondents, Age,

and Gender

Potential

Exposures

Mean Duration (minutes/day) - BOYS

birth

to 1

month

1 to <3

months

3 to <6

months

6 to <12

months

1 to <2

years

2 to <3

years

3 to <6

years

6 to <11

years

11

yearsb

0-11

yrs

Gasoline Fumes 3 9 0 2 1 4 2 2 7 3

Gas Oven Fumes 0 0 2 2 1 3 0 1 0 1

Sample Sizes

(Unweighted N's)

3 7 15 31 54 62 151 239 62 624

Potential

Exposures

Mean Duration (minutes/day) - GIRLS

birth

to 1

month

1 to <3

months

3 to <6

months

6 to <12

months

1 to <2

years

2 to <3

years

3 to <6

years

6 to <11

years

11

yearsb

0-11

yrs

Gasoline Fumes 0 3 0 3 1 2 1 2 1 2

Gas Oven Fumes 0 0 0 0 0 3 2 1 0 1

Sample Sizes

(Unweighted N's)

4 10 11 23 43 50 151 225 59 576

a

 Respondents with missing data were excluded.

b

The source data end at 11 years of age, so the 11 to <16 year category is truncated and the 16 to <21 year category is not included.

Source: EPA Analysis of source data used by Wiley et al . (1991).
9-30

Table 9-15. Mean Time Spent Indoors and Outdoors Grouped by Age

Age Groups Boys Girls

sample

size

time indoors

(min/day)

time outdoors

(min/day)

sample

size

time indoors

(min/day)

time outdoors

(min/day)

birth to <1 month 3 1440 0 4 1440 0

1 to <3 months 7 1432 8 10 1431 9

3 to <6 months 15 1407 33 11 1421 19

6 to <12 months 31 1322 118 23 1280 160

1 to <2 years 54 1101 339 43 1164 276

2 to <3 years 62 1121 319 50 1102 338

3 to <6 years 151 1117 323 151 1140 300

6 to <11 years 239 1145 295 225 1183 255

11 yearsa 62 1166 274 59 1215 225

All Ages 624 1181 258 576 1181 258

a

The source data end at 11 years of age, so the 11 to <16 year category is truncated and the 16 to <21 year category is not included.

Note: Indoor and outdoor minutes may not sum to 1440 due to rounding errors.

Source: EPA Analysis of source data used by Wiley et al . (1991).
9-31

Table 9-16. Water and Soil Contact Exposure Factors for Childrena

Water Contact Soil Contact

Bathingb Swimming

Central Upper Central Upper Central Upper

Event time

and

frequency

20 min/event

1 event/day

350 days/yr

60 min/event

1 event/day

350 days/yr

Site-specific Site-specific 1event/day

days/yr is

site -specific

1 event/day

350 days/yr

Exposure

Duration c

6 years 6 years 6 years 6 years 6 years 6 years

a Children age range defined as 1 to 6 years.

a

Bathing represents baths as well as showers.

C

 Exposure duration is set at 6 years because this corresponds to age range addressed by these factors.

Source: U.S. EPA, , 2004

Table 9-17. Number of Showers Taken Per Day

Age (years) Total N

Showers per day

0 1 2 3 Don’t Know

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

37

53

67

187

245

258

232

36

48

54

153

122

51

23

1

5

10

25

95

150

147

0

0

2

7

25

53

57

0

0

0

1

1

3

5

0

0

1

1

2

1

0

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database)
9-32

Table 9-18. Time (minutes) Spent Taking a Shower and Spent in the Shower Room After Taking a Shower by the

Number of Respondents

Age Total N

Minutes per Shower

0 1-10 11-20 21-30 31-40 41-50 51-60 61+ DK

Time (minutes) Spent Taking Showers

0 to <1

1to < 2

2 to <3

 3 to <6

6 to <11

11 to <16

16 to <21

37

53

67

187

245

258

232

36

48

54

153

122

51

23

0

1

3

15

47

76

70

1

2

5

11

47

81

74

0

2

3

5

18

30

40

0

0

0

1

3

10

7

0

0

0

0

2

4

10

0

0

1

1

4

4

6

0

0

0

0

0

0

1

0

0

1

1

2

2

1

Time (minutes) Spent in the Shower Room Immediately After Showering

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

1

4

12

34

122

206

210

0

2

1

1

9

12

14

1

2

10

28

96

156

160

0

0

1

4

11

23

26

0

0

0

1

3

8

5

0

0

0

0

0

3

1

0

1

0

0

0

2

1

0

0

0

0

0

1

1

0

0

0

0

0

0

1

0

0

0

0

3

1

1

NOTE: * - Missing data; DK = don’t know; N = sample size; Refused = Refused to answer. A value of 61 for number of minutes signifies that

more than 60 minutes were spent.

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database)

Table 9-19. Time Spent Taking a Shower and Spent in the Shower Room Immediately After Showering

Time spent taking a shower (minutes)

Age N Mean Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

1

5

12

33

119

204

207

1

20

22

17

18

18

20

1

5

5

3

4

3

3

---

5.4

5

3.6

5

4.0

5

---

5.8

5

4.3

5

5

5

---

7

5

5

5

5

5

---

9

5.5

5

7

6.3

8

—

15

13.8

10

10

10

10

—

20

20

15

15

15

15

—

30

30

20

20

20

30

—

30

30

30

30

30

40

—

30

43.5

34

40.5

40

45

—

30

53.4

47.2

56.8

49.7

60

—

30

56.7

53.6

60

60

60

1

30

60

60

60

60

61

Time spent in shower room immediately after showering (minutes)

Age N Mean Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

1

5

12

33

119

204

207

1

10

5

7

6

8

8

1

0

0

0

0

0

0

—

0

0.1

0.3

0

0

0

—

0

0.2

0.6

0

0

0

—

0

0.6

1.6

0

0

0

—

0

1

2

1

1

1

—

0

1

3

2

3

2.5

—

1

3.5

5

5

5

5

—

5

6.3

10

10

10

10

—

29

10

15

12.6

18.5

15

—

37

12.3

20

15.5

30

20

—

41.8

13.9

21.8

26.4

39.7

30

—

43.4

14.5

23.4

30

44.9

39.4

1

45

15

25

30

60

61

NOTE: N = doer sample size. Percentiles are the percentage of doers below or equal to a given number of minutes. A value of 61 for number

of minutes signifies that more than 60 minutes were spent.

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database)
9-33

Table 9-20. Time spent bathing, showering, and in bathroom after bathing and showering (distribution)

Age

Time, min

Total N 0 1-10 11-20 21-30 31-40 41-50 51-60 61-70 71-80 81-90 91+

Duration of Bath

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

26

37

48

125

89

38

17

0

0

0

0

0

0

0

9

6

8

20

12

5

1

10

13

21

42

38

16

6

6

16

15

49

30

11

4

0

1

0

2

2

4

1

0

1

2

4

3

0

1

1

0

2

6

3

1

3

0

0

0

2

1

1

1

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Time Spent in the Bathroom Immediately Following a Bath

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

26

37

48

125

89

38

17

9

8

14

26

19

2

1

17

29

30

90

66

26

12

0

0

4

8

3

7

2

0

0

0

1

1

2

1

0

0

0

0

0

1

0

0

0

0

0

0

0

1

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Sum of Bath Duration and Time Spent in Bathroom Following Bath

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

26

37

48

125

89

38

17

0

0

0

0

0

0

0

6

1

5

11

0

0

0

10

11

15

32

0

0

0

4

11

11

30

0

0

0

5

12

11

31

0

0

0

0

2

4

3

0

0

0

0

0

1

5

0

0

0

1

0

1

4

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Duration of Shower

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

1

5

12

33

119

204

207

0

0

0

0

0

0

0

0

1

3

15

46

76

70

1

2

5

11

46

80

73

0

2

3

5

18

30

40

0

0

0

1

3

10

7

0

0

0

0

2

4

10

0

0

1

1

4

4

6

0

0

0

0

0

0

1

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Time Spent in the Bathroom Immediately Following a Shower

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

1

5

12

33

119

204

207

0

2

1

1

9

12

14

1

2

10

27

96

155

159

0

0

1

4

11

23

26

0

0

0

1

3

8

5

0

0

0

0

0

3

1

0

1

0

0

0

2

0

0

0

0

0

0

1

1

0

0

0

0

0

0

1

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Sum of Shower Duration and Time Spent in Bathroom Following Shower

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

1

5

12

33

119

204

207

0

0

0

0

0

0

0

0

1

2

5

13

18

22

1

0

3

11

55

80

72

0

3

3

9

25

50

46

0

0

2

5

13

23

34

0

0

1

2

8

14

13

0

1

0

0

2

13

10

0

0

1

1

2

6

5

0

0

0

0

0

0

2

0

0

0

0

1

0

2

0

0

0

0

0

0

1a

Note: Figures are based on respondents who took at least one shower/bath. A value of 61 was used for any shower, bath, or bathroom stay longer

than 60 minutes.

a

121 minutes. 

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database)

Table 9-21.Time spent bathing, showering, and in bathroom after bathing and showering (percentiles)
9-34

Age Total

N

Mean Min

Percentile

Max

1 2 5 10 25 50 75 90 95 98 99

Duration of Bath

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

26

37

48

125

89

38

17

19

23

23

24

24

25

33

5

10

1

5

5

5

10

5

10

2.9

5

5

6

11

5

10

5

5

5

6

12

6

10

7

6

10

10

14

8

10

10

10

10

10

18

10

15

15

15

15

16

20

18

20

20

25

20

20

30

28

30

30

30

30

30

45

30

30

30

35

31

40

60

30

32

45

60

46

43

60

45

41

60

60

60

60

61

53

43

60

61

60

61

61

60

45

60

61

61

61

61

Time Spent in the Bathroom Immediately Following a Bath

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

26

37

48

125

89

38

17

2

3

4

4

4

9

11

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

0

0

0

0

0

1

2

0

0

0

0

0

1

3

0

1

0

1

1

2

5

1

2

1.5

2

3

5

10

3

5

5

5

5

14

10

9

5

10

10

10

20

19

10

6

15

15

10

26

29

10

10

15

15

16

33

39

10

10

18

19

21

36

42

10

10

20

30

30

40

45

Sum of Bath Duration and Time Spent in Bathroom Following Bath

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

26

37

48

125

89

38

17

22

26

26

28

28

33

45

6

10

6

5

6

7

15

7

10

7

6

6

8

15

8

11

8

7

9

10

16

9

12

10

10

10

12

17

10

16

14

12

13

16

21

12

17

16

18

20

23

30

19

30

23

30

25

31

40

29

32

34

32

33

41

60

32

35

45

48

41

52

73

38

41

50

60

60

64

77

55

46

60

66

63

70

82

63

48

61

69

71

70

83

70

50

61

76

80

70

85

Duration of Shower

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

1

5

12

33

119

204

207

15

20

22

17

18

18

20

15

5

5

3

4

3

3

—

5

5

4

5

4

5

—

6

5

4

5

5

5

—

7

5

5

5

5

5

—

9

6

5

7

6

8

—

15

14

10

10

10

10

—

20

20

15

15

15

15

—

30

30

20

20

20

30

—

30

30

30

30

30

40

—

30

44

34

41

40

45

—

30

53

47

57

50

60

—

30

57

54

60

60

60

15

30

60

60

60

60

61

Time Spent in the Bathroom Immediately Following a Shower

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

1

5

12

33

119

204

207

1

10

5

7

6

8

8

1

0

0

0

0

0

0

---

0

0

0

0

0

0

—

0

0

1

0

0

0

—

0

1

2

0

0

0

—

0

1

2

1

1

1

—

0

1

3

2

3

3

—

1

4

5

5

5

5

—

5

6

10

10

10

10

—

29

10

15

13

19

15

—

37

12

20

16

30

20

—

42

14

22

26

40

30

—

43

14

23

30

45

39

1

45

15

25

30

60

61

Sum of Shower Duration and Time Spent in Bathroom Following Shower

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

1

5

12

33

119

204

207

16

30

27

24

24

26

28

16

6

6

8

5

4

4

—

7

6

8

6

5

5

—

8

7

8

6

7

7

—

10

8

8

8

10

10

—

14

11

8

10

11

10

—

25

19

13

15

15

15

—

30

21

25

20

22

25

—

30

33

30

30

35

35

—

48

44

40

43

50

50

—

54

56

45

50

60

60

—

58

65

57

61

65

74

—

59

67

64

68

70

89

16

60

70

70

90

70

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: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database)
9-35

Table 9-22. Range of Number of Times Washing the Hands at Specified Daily Frequencies by the Number of

Respondents

Age Total N

Number of Times/Day

0 1-2 3-5 6-9 10-19 20-29 30+ DK

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

37

53

67

187

245

258

232

2

7

0

2

2

8

0

15

8

15

37

47

37

23

12

23

39

101

131

128

115

2

8

10

27

34

49

47

1

4

0

10

16

22

38

1

0

1

1

3

5

4

0

2

0

2

1

2

3

4

1

2

7

11

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: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database)

Table 9-23. Number of Minutes Spent Working or Being Near Excessive Dust in the Air (minutes/day)

Age Total

N

DK Min

Percentiles (minutes per day)

Max

1 2 5 10 25 50 75 90 95 98 99

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

2

5

1

15

12

14

14

0

0

0

0

1

1

0

5

0

121

0

0

0

2

—

---

—

0

0

0

2

—

---

—

1

0

0

3

—

---

—

1

1

1

4

—

---

—

2

2

2

7

—

---

—

8

5

6

16

—

---

—

60

45

38

53

—

---

—

151

136

113

165

—

---

—

408

234

162

324

—

---

—

710

677

639

449

—

---

—

755

738

719

464

—

---

—

800

800

800

480

121

121

121

800

800

800

480

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: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database)
9-36

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

Age Total N

in survey

N

not

answering

N

answering

Number of Times per Day Vehicle Was Started

0 1-2 3-5 6-9 10+ DK

All Motor Vehicle Starts in Garage or Carport (number of respondents)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

41

65

68

213

280

259

304

22

53

50

144

217

207

177

10

22

24

71

104

94

84

10

18

16

48

64

68

48

2

12

9

20

42

33

31

0

0

0

4

4

8

9

0

1

1

0

0

1

2

0

0

0

1

3

3

3

Motor Vehicle Starts in Garage or Carport with Door Closed (number of respondents)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

41

65

68

213

280

259

304

22

53

50

144

217

207

177

22

50

47

135

209

198

163

0

1

2

6

5

5

5

0

1

0

1

0

1

5

0

0

0

0

0

0

1

0

0

0

0

0

0

0

0

1

1

2

3

3

3

Note: "DK" = respondent answered “don't know” N = doer sample size.

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database)
9-37

Table 9-25. Number of Minutes Spent Playing on Dirt, Grass , or Sand/Gravel

Number of Minutes Spent Playing on Dirt (number of respondents)

Age

N 0 1-10 11-20 21-30 31-40 41-50 51-60 61-70 71-80 81-90 91-

100

101-

110

111-

120

121a 180a 240a 300a 360a 420a 48

0 to <11to < 22 to <33 to <66 to <1111 to <1616 to <21

113962

197103

37

9

6

2437975417

5

344

13

430

1156520

005

15

852

0100000

0112100

024

1712

40

0000000

0000000

0013110

0000000

0000000

0119520

130

12

600

0014110

0011000

0000000

0000000

0000000

0000000

Number of Minutes Spent Playing on Grass (number of respondents)

Age

N 0 1-10 11-20 21-30 31-40 41-50 51-60 61-70 71-80 81-90 91-

100

101-

110

111-

120

121a 180a 240a 300a 360a 420a 48

0 to <11to < 22 to <33 to <66 to <1111 to <1616 to <21

113962

197103

37

9

236

2314

12

238

11

510

166

11

711

24

111512

71

1000110

0112301

076

3921

81

0001000

0010000

0138311

0000100

1000000

055

1612

71

167

2611

50

012

10

400

0118310

1005100

0010100

0001000

0002000

Number of Minutes Spent Playing on Sand/Gravel (number of respondents)

Age

N 0 1-10 11-20 21-30 31-40 41-50 51-60 61-70 71-80 81-90 91-

100

101-

110

111-

120

121a 180a 240a 300a 360a 420a 48

0 to <11to < 22 to <33 to <66 to <1111 to <1616 to <21

103861

195102

37

9

8

2232935520

4

048

11

310

211

12

430

045

12

831

0101000

0023300

022

2412

21

0000000

0100100

0007000

0001010

0000000

0044530

023

13

711

0003220

0001001

0011100

0000000

0000000

0000000

Note: "DK" = Don't know. 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 mSource: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database)
9-38

Table 9-26. Number of Minutes Spent Playing on Dirt, Sand/Gravel, or Grass (minutes/day)

Age Total

N

Mean Min

Percentile

Max

1 2 5 10 25 50 75 90 95 98 99

Time Spent Playing on Dirt: Whole Population

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

11

37

61

179

98

35

7

15

20

31

31

34

27

9

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

0

10

10

20

59

60

30

15

20

84

60

120

120

77

30

71

121

120

121

121

120

30

101

121

228

180

124

139

30

111

121

432

180

193

160

30

121

121

720

240

600

180

30

Time Spent Playing on Dirt: DOERS ONLY

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

5

13

24

82

44

18

2

33

56

79

67

75

52

30

2

5

5

1

2

1

30

2

5

5

1

3

2

30

3

5

5

1

5

2

30

4

5

5

1

10

4

30

5

6

7

6

15

9

30

10

10

15

30

30

19

30

10

45

30

60

60

30

30

20

120

60

120

120

60

30

81

121

162

121

121

120

30

101

121

231

177

121

129

30

113

121

499

180

239

160

30

117

121

610

191

419

170

30

121

121

720

240

600

180

30

Time Spent Playing on Sand/Gravel: Whole Population

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

10

37

58

186

101

36

8

4

17

27

33

33

33

56

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

2

0

0

15

0

30

30

60

60

38

75

16

60

120

120

120

120

157

18

84

121

121

121

136

198

19

121

121

180

180

180

223

20

121

198

189

180

180

232

20

121

300

300

300

180

240

Time Spent Playing on Sand/Gravel: DOERS ONLY

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

2

15

26

93

46

16

4

18

43

60

65

73

75

113

15

5

1

3

5

1

30

15

5

1

3

7

3

31

15

5

1

3

10

5

32

15

5

1

5

11

12

35

16

7

3

8

15

15

39

16

15

10

25

30

26

53

18

30

30

60

60

60

91

19

60

120

90

120

120

151

20

103

121

121

121

151

204

20

121

121

145

165

180

222

20

121

211

190

192

180

233

20

121

255

245

246

180

236

20

121

300

300

300

180

240

Time Spent Playing on Grass: Whole Population

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

11

38

59

180

99

36

8

59

67

73

93

73

70

45

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

9

1

0

0

1

0

2

16

15

28

20

30

11

30

60

30

60

60

60

38

73

120

120

121

120

120

68

121

121

121

186

121

121

99

211

130

186

300

186

121

110

264

196

341

445

242

157

116

282

218

511

493

301

198

118

300

240

720

540

360

240

120

Time Spent Playing on Grass: DOERS ONLY

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

9

35

53

157

85

32

6

72

73

82

106

85

79

60

1

5

1

1

1

1

15

1

7

2

2

5

5

16

1

8

3

2

9

10

17

1

10

3

10

11

23

19

2

15

5

15

17

30

23

20

25

20

60

30

30

34

30

60

60

70

60

60

53

110

120

120

121

120

120

83

157

121

121

240

156

121

105

228

139

204

300

228

121

113

271

199

355

473

259

166

117

286

220

533

506

310

203

119

300

240

720

540

360

240

120

NOTE: A value of "121" for number of minutes signifies that more than 120 minutes were spent. N = doer sample size. 

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database)
9-39

Table 9-27. Number of Times Swimming in a Month in Freshwater Swimming Pool by the Number of Respondents

Age Total N

Times/Month

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

10

8

18

45

76

66

50

1

2

3

5

15

19

6

4

3

4

7

10

10

6

1

1

1

6

5

6

2

0

0

0

5

5

3

6

0

1

1

2

5

5

6

2

0

1

1

3

4

2

0

0

0

1

1

1

2

0

1

1

2

3

3

1

0

0

1

0

0

1

0

1

0

2

2

6

4

5

0

0

0

0

0

0

1

0

0

2

0

5

1

1

0

0

0

1

0

0

0

0

0

0

1

0

0

0

0

0

1

5

7

2

0

0

0

0

0

2

0

0

Age Total N

Times/Month

18 20 23 24 25 26 28 29 30 32 40 42 45 50 60 DK

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

10

8

18

45

76

66

50

0

0

0

0

0

1

0

0

0

0

2

3

2

6

0

0

0

0

0

0

0

0

0

0

0

1

0

0

0

0

0

1

1

0

1

0

0

0

0

0

0

2

0

0

0

0

0

0

0

0

0

1

0

0

0

0

1

0

0

3

3

2

3

0

0

0

1

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

0

0

0

0

0

0

0

1

0

0

0

0

0

0

1

0

Note: "DK" = respondent answered don't know; N= sample size

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database)

Table 9-28. Number of Minutes Spent Swimming in a Month in Freshwater Swimming Pool (minutes/month)

Age N Mean Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

10

7

18

42

72

65

50

313

251

636

946

868

667

868

6

45

15

6

8

4

2

7

46

16

8

13

8

3

9

47

17

9

17

11

5

12

50

19

12

30

20

25

19

54

27

40

60

30

39

30

60

60

83

150

90

124

75

90

120

420

425

240

465

338

300

600

1013

1110

600

1172

586

650

1950

2700

2340

1476

1860

1198

778

2817

4715

2781

2088

3116

1565

854

3215

5405

4644

5366

3931

1688

880

3347

5418

5574

6048

4680

1810

905

3480

5430

6000

7200

5430

Note: A value of 181 for number of minutes signifies that more than 180 minutes were spent. N = doer sample size. 

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).
9-40

Table 9-29. Time Spent Sleeping/Napping: Whole Population and Doers Only: Percentile Values

 

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent sleeping/napping (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

485

360

270

0

120

0

0

519

483

365

480

295

320

239

546

510

470

510

390

376

295

579

579

523

539

458

415

360

613

627

594

573

510

450

390

668

700

635

630

570

510

450

762

780

708

675

625

558

525

873

855

805

735

660

630

615

1011

925

870

795

720

705

690

1080

962

917

840

750

762

750

1121

987

937

893

831

809

840

1144

1098

944

916

868

907

906

1175

1320

990

1110

945

1015

1317

Time spent sleeping/napping (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

356

497

465

480

485

360

270

420

120

150

85

519

483

365

491

295

341

252

546

510

470

510

390

379

299

579

579

523

540

458

415

360

613

627

594

578

510

450

390

668

700

635

630

570

510

450

762

780

708

675

625

560

525

873

855

805

738

660

630

615

1011

925

870

795

720

705

690

1080

962

917

840

750

762

751

1121

987

937

893

831

809

840

1144

1098

944

916

868

907

906

1175

1320

990

1110

945

1015

1317

Note: A Value of 181 for number of minutes signifies that more than 180 minutes were spent. N = doer sample size. Percentiles are the

percentage of doers below or equal to a given number of minutes.

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).

Table 9-30. Time Spent Attending School Full-Time: Whole Population and Doers Only: Percentile Values

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent attending school full-time (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

390

409

270

0

0

334

392

435

445

408

0

204

502

510

460

464

445

83

546

564

558

525

487

489

265

594

618

581

570

500

551

550

665

710

630

645

595

825

Time spent attending school full-time (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

3

9

20

71

234

217

162

60

20

20

30

60

10

20

-

-

37

37

125

86

46

-

-

53

66

164

108

78

-

-

103

128

211

270

126

-

-

119

165

311

343

195

-

-

226

203

370

385

270

-

-

458

395

390

415

370

-

-

520

510

425

440

420

-

-

576

558

460

467

459

-

-

632

583

497

485

519

-

-

679

615

570

505

567

-

-

694

627

600

548

609

550

665

710

630

645

595

825

Note: A Value of 181 for number of minutes signifies that more than 180 minutes were spent. N = doer sample size. Percentiles are the

percentage of doers below or equal to a given number of minutes.

- For sample sizes less than 10, percentiles were not calculated.

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database)
9-41

Table 9-31. Time Spent in Active Sports: Whole Population and Doers Only: Percentile Values

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent on active sports (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

30

60

74

0

60

68

110

135

172

168

145

90

131

180

242

272

245

180

131

180

257

330

371

309

285

143

201

319

408

435

425

386

155

270

390

630

975

1065

565

Time spent on active sports (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

13

24

26

97

175

179

117

25

10

15

15

2

5

5

26

15

18

20

12

5

15

26

19

20

29

15

15

15

28

30

26

30

20

15

20

31

33

30

30

30

30

30

40

60

41

60

60

60

60

60

73

98

120

110

115

120

90

131

179

180

193

180

180

132

180

253

315

312

261

272

143

201

314

354

393

314

371

150

240

360

559

450

442

501

153

255

375

625

522

533

519

155

270

390

630

975

1065

565

Note: A Value of 181 for number of minutes signifies that more than 180 minutes were spent. N = doer sample size. Percentiles are the

percentage of doers below or equal to a given number of minutes.

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).

Table 9-32. Time Spent on Exercise: Whole Population and Doers Only: Percentile Values

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent on exercise (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

30

60

122

25

0

0

100

70

151

354

30

0

54

137

114

176

670

150

60

525

450

245

300

Time spent on exercise (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

2

4

1

7

20

28

41

-

-

-

-

15

20

15

-

-

-

-

17

21

15

-

-

-

-

19

23

15

-

-

-

-

25

27

25

-

-

-

-

30

30

30

-

-

-

-

60

42

40

-

-

-

-

100

60

90

-

-

-

-

146

101

145

-

-

-

-

226

128

180

-

-

-

-

284

148

240

-

-

-

-

384

194

260

-

-

-

-

417

219

280

-

-

-

-

450

245

300

Note: A Value of 181 for number of minutes signifies that more than 180 minutes were spent. N = doer sample size. Percentiles are the

percentage of doers below or equal to a given number of minutes.

- For sample sizes less than 10, percentiles were not calculated.

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).

Table 9-33. Time Spent on Outdoor Recreation: Whole Population and Doers Only: Percentile Values
9-42

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent on outdoor recreation (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

15

60

142

142

103

0

0

28

172

226

191

189

0

0

370

630

574

465

570

Time spent on outdoor recreation (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

0

0

4

11

17

22

13

-

-

15

30

60

5

30

-

-

-

30

60

5

35

-

-

-

30

60

5

41

-

-

-

30

60

5

57

-

-

-

30

66

11

77

-

-

-

60

120

60

130

-

-

-

150

165

126

180

-

-

-

240

245

180

300

-

-

-

585

351

234

420

-

-

-

608

403

411

480

-

-

-

621

506

446

534

-

-

-

626

540

456

552

-

-

370

630

574

465

570

Note: A Value of 181 for number of minutes signifies that more than 180 minutes were spent. N = doer sample size. Percentiles are the

percentage of doers below or equal to a given number of minutes.

- For sample sizes less than 10, percentiles were not calculated.

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).

Table 9-34. Time Spent on Walking: Whole Population and Doers Only: Percentile Values

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent on walking (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

9.2

0

10

4

14

30

20

29

10

17

20

30

55

45

64

40

45

35

40

79

90

104

58

54

60

55

130

127

160

60

60

60

170

190

410

Time spent on walking (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

9

9

19

44

118

190

128

4

4

1

1

1

1

1

-

-

1

1

1

1

1

-

-

1

1

1

1

2

-

-

2

1

2

2

2

-

-

2

2

2

3

3

-

-

7

5

5

5

5

-

-

10

15

10

14

18

-

-

28

30

25

30

32

-

-

51

56

40

60

62

-

-

56

60

51

78

120

-

-

58

60

65

134

148

-

-

59

60

94

154

175

160

60

60

60

170

190

410

Note: A Value of 181 for number of minutes signifies that more than 180 minutes were spent. N = doer sample size. Percentiles are the

percentage of doers below or equal to a given number of minutes.

- For sample sizes less than 10, percentiles were not calculated.

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).
9-43

Table 9-35. Time Spent Bathing: Whole Population and Doers Only: Percentile Values

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent on bathing (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

15

15

17

15

15

10

15

30

30

30

30

25

20

27

40

42

45

45

30

30

40

50

47

60

60

45

45

45

68

60

60

60

60

60

60

78

60

68

77

60

60

60

90

90

75

125

690a

90

90

Time spent on bathing (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

37

79

84

208

298

299

362

5

10

6

5

2

1

1

7

10

9

5

5

4

5

9

10

10

10

5

5

5

10

10

11

12

7

5

5

10

15

15

15

10

8

10

15

15

15

20

15

10

15

30

30

30

30

20

20

20

30

30

30

32

30

30

30

47

45

57

53

42

40

45

62

60

60

60

50

50

50

76

60

63

75

60

60

60

83

67

71

85

65

60

60

90

90

75

125

690

90

90

a

 self-reported value of 690 appears in source data; could be a reporting or processing error.

Note: A Value of 181 for number of minutes signifies that more than 180 minutes were spent. N = doer sample size. Percentiles are the

percentage of doers below or equal to a given number of minutes.

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).

Table 9-36. Time Spent Eating: Whole Population and Doers Only: Percentile Values

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent on eating (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

15

0

0

0

0

6

10

15

0

0

0

0

12

10

15

0

0

0

0

36

29

20

15

10

0

0

45

40

30

28

20

10

0

73

60

60

45

35

30

20

110

90

89

75

60

45

40

145

120

120

105

88

74

65

194

167

157

135

115

100

105

224

206

176

150

139

120

135

334

233

198

180

155

146

192

345

244

208

217

176

162

210

345

270

270

265

255

205

630

Time spent on eating (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

62

117

118

349

480

432

426

10

10

15

2

5

2

2

16

10

15

10

10

5

5

23

12

15

15

10

7

9

40

30

20

20

15

10

10

46

40

30

30

20

20

15

77

60

60

45

40

30

30

110

90

89

75

60

50

45

148

120

120

105

90

75

75

195

167

157

135

115

100

105

224

206

176

150

140

125

144

335

234

198

180

157

148

197

345

244

208

218

179

163

210

345

270

270

265

255

205

630

Note: A Value of 181 for number of minutes signifies that more than 180 minutes were spent. N = doer sample size. Percentiles are the

percentage of doers below or equal to a given number of minutes.

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).
9-44

Table 9-37. Time Spent at Restaurants: Whole Population and Doers Only: Percentile Values

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent at restaurants (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

20

45

30

45

21

15

35

105

69

62

62

52

45

60

240

105

88

92

90

85

90

380

194

102

111

120

110

137

466

330

120

120

130

180

315

645

Time spent at restaurants (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

10

15

17

43

57

78

135

10

5

20

4

5

2

1

12

6

21

7

5

3

4

14

8

22

9

6

7

5

19

12

24

10

10

10

10

28

21

28

16

15

18

17

45

33

45

30

30

30

30

60

55

60

45

45

45

60

85

83

80

90

60

65

170

132

99

102

120

107

102

334

231

110

116

120

124

141

437

290

116

118

122

140

223

537

310

118

119

126

158

283

546

330

120

120

130

180

315

645

Note: A Value of 181 for number of minutes signifies that more than 180 minutes were spent. N = doer sample size. Percentiles are the

percentage of doers below or equal to a given number of minutes.

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).

Table 9-38. Time Spent Indoors at School: Whole Population and Doers Only: Percentile Values

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent at indoors at school (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

397

420

308

0

0

0

416

444

459

430

0

22

193

540

480

495

495

46

156

414

569

552

578

566

100

453

503

589

601

630

629

165

665

545

630

665

855

855

Time spent indoors at school (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

2

8

11

71

235

229

171

60

5

10

5

5

15

15

-

-

10

23

64

38

22

-

-

10

34

129

96

31

-

-

10

110

195

132

90

-

-

10

160

305

290

185

-

-

83

228

370

395

270

-

-

269

418

400

420

388

-

-

388

540

435

450

440

-

-

510

570

480

495

525

-

-

528

590

540

559

576

-

-

538

615

612

631

726

-

-

542

627

643

696

801

165

665

545

630

665

855

855

- For sample sizes less than 10, percentiles were not calculated.

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).
9-45

Table 9-39. Time Spent on School Grounds/Playgrounds: Whole Population and Doers Only: Percentile Values

Age Total

N

Min

Percentile

Max

1 2 5 10 25 50 75 90 95 98 99

Time Spent on School Grounds/Playground: Whole Population (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

10

20

0

0

0

0

0

60

80

50

0

0

50

64

121

120

135

53

0

131

127

170

160

180

140

0

175

625

315

570

510

Time Spent on School Grounds/Playground: DOERS ONLY (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

1

0

5

12

52

62

34

140

-

10

20

10

3

10

-

-

-

22

10

4

10

-

-

-

24

10

5

10

-

-

-

31

10

5

13

-

-

-

42

15

5

18

-

-

-

59

30

21

46

-

-

-

118

59

53

95

-

-

-

138

106

95

161

-

-

-

150

169

149

201

-

-

-

364

217

178

305

-

-

-

521

280

217

418

-

-

-

573

298

360

464

140

-

175

625

315

570

510

Time Spent in parks or golf courses: Whole Population (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

24

71

72

114

150

45

0

126

163

328

265

381

63

25

246

220

483

452

546

85

360

755

585

665

1065

870

Time Spent Playing on parks or golf courses: DOERS ONLY (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

3

2

7

26

34

38

47

30

30

21

25

25

15

1

-

-

-

26

30

15

7

-

-

-

28

35

15

14

-

-

-

31

43

15

15

-

-

-

44

52

27

24

-

-

-

63

73

86

60

-

-

-

113

123

164

160

-

-

-

165

394

266

308

-

-

-

273

568

470

557

-

-

-

388

644

851

633

-

-

-

505

662

954

677

-

-

-

545

663

1010

773

85

360

755

585

665

1065

870

Time Spent in a pool, river, or lake: Whole Population (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

14

0

0

0

0

0

0

228

85

220

60

145

0

0

352

163

295

160

240

0

118

435

630

375

235

570

Time Spent in a pool, river, or lake: DOERS ONLY (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

0

1

6

9

24

16

22

-

118

95

45

25

58

20

-

-

-

-

26

58

22

-

-

-

-

27

59

24

-

-

-

-

32

59

31

-

-

-

-

46

60

40

-

-

-

-

75

60

55

-

-

-

-

155

85

125

-

-

-

-

294

206

238

-

-

-

-

319

225

415

-

-

-

-

359

228

548

-

-

-

-

370

232

564

-

-

-

-

373

234

567

-

118

435

630

375

235

570

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 

- For sample sizes less than 10, percentiles were not calculated.

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).
9-46

Table 9-40. Time Spent at Home in Kitchen: Whole Population and Doers Only: Percentile Values

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent at home in kitchen (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

10

40

30

30

30

24

15

70

90

75

75

60

55

50

109

132

120

105

105

90

90

125

195

146

150

135

130

130

134

232

173

180

150

180

170

158

242

188

222

196

249

195

195

392

215

362

690

450

545

Time spent at home in kitchen (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

33

76

80

252

342

323

305

10

10

10

2

1

1

1

10

10

10

5

2

2

2

10

13

11

10

5

4

3

13

19

15

15

10

5

5

15

30

15

15

15

10

10

30

45

30

30

30

20

20

70

70

60

60

50

40

35

90

110

105

90

79

65

65

124

173

136

133

120

114

120

133

214

155

165

145

150

159

157

240

184

210

172

218

194

176

281

195

232

229

281

209

195

392

215

362

690

450

545

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).

Table 9-41. Time Spent at Home in Living Room/Family Room/Den: Whole Population and Doers Only: Percentile

Values

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent at home in living room/family room/den (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

90

25

56

45

30

36

0

210

120

138

122

95

120

120

420

279

239

240

210

240

240

666

410

346

376

322

395

370

724

533

499

476

420

570

501

788

616

599

680

547

687

690

938

652

680

742

612

774

819

1180

810

1125

900

695

1305

1080

Time spent at home in living room/family room/den (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

54

93

105

290

403

380

352

25

10

1

5

5

2

5

28

15

5

8

10

10

10

31

19

10

19

10

16

15

57

25

22

30

20

30

24

90

60

34

50

30

45

40

136

90

90

90

60

85

85

268

180

150

153

130

165

165

450

310

255

270

240

275

285

686

444

377

415

349

436

440

744

540

527

498

449

594

547

789

642

603

705

579

705

720

973

667

691

778

655

776

909

1180

810

1125

900

695

1305

1080

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).
9-47

Table 9-42. Time Spent at Home in Dining Room: Whole Population and Doers Only: Percentile Values

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent at home in dining room (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

17

30

10

5

0

0

30

60

80

60

57

33

30

70

90

105

96

70

65

45

86

176

118

133

120

119

90

96

260

146

150

135

164

112

105

315

150

300

225

390

330

Time spent at home in dining room (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

9

32

34

93

126

90

67

15

10

15

10

5

5

5

16

12

15

10

5

5

5

17

13

15

10

5

5

7

21

16

18

15

6

10

15

27

30

29

16

15

15

15

30

34

30

30

30

30

20

65

53

60

55

45

38

35

75

66

90

85

60

69

60

93

110

105

120

98

122

90

99

237

134

150

135

166

124

103

287

150

209

150

202

135

104

301

150

286

196

283

201

105

315

150

300

225

390

330

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).

Table 9-43. Time Spent at Home in Bathroom: Whole Population and Doers Only: Percentile Values

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent at home in bathroom (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

1

0

0

0

10

0

15

20

15

15

15

20

30

30

30

30

30

30

32

40

45

60

49

45

45

59

59

60

62

65

60

60

65

81

80

138

90

81

86

105

87

239

290

120

118

97

123

90

600

345

270

535

220

547

Time spent at home in bathroom (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

31

77

88

240

356

335

392

5

6

2

1

1

1

1

7

6

3

1

2

2

2

8

8

5

2

3

2

5

10

10

12

5

5

5

5

15

15

15

11

9

6

10

18

15

15

15

15

12

15

30

30

30

30

25

20

25

40

30

45

38

35

35

40

60

57

60

60

50

50

60

78

60

70

75

60

64

72

87

176

208

112

90

90

111

89

349

319

123

180

100

135

90

600

345

270

535

220

547

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).
9-48

Table 9-44. Time Spent at Home in Bedroom: Whole Population and Doers Only: Percentile Values

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent at home in bedroom (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

56

5

92

0

0

0

104

340

91

210

0

20

0

468

443

419

432

304

134

60

566

559

517

540

480

403

335

653

645

618

630

585

543

475

750

808

718

695

660

645

595

863

884

835

790

735

745

720

972

975

894

875

840

860

855

1092

1029

931

945

906

950

960

1119

1190

979

1033

1005

1027

1082

1179

1325

990

1135

1096

1118

1146

1275

1440

1040

1440

1440

1277

1375

Time spent at home in bedroom (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

61

116

116

353

486

457

463

435

330

30

165

120

15

15

453

362

215

210

183

55

34

470

384

266

268

261

115

100

495

450

484

464

439

179

273

590

570

520

540

513

430

395

660

656

620

630

599

550

480

750

810

720

695

660

646

600

865

885

836

790

735

750

725

975

975

896

875

843

860

859

1095

1030

931

945

912

951

974

1119

1191

981

1034

1005

1029

1090

1182

1328

990

1137

1100

1122

1147

1275

1440

1040

1440

1440

1277

1375

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).

Table 9-45. Time Spent at Home in Study/Office: Whole Population and Doers Only: Percentile Values

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent at home in study/office (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

25

0

0

81

22

0

0

125

345

120

285

180

Time spent at home in study/office (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

0

0

2

3

4

8

8

-

-

30

20

20

2

10

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

125

345

120

285

180

- For sample sizes less than 10, percentiles were not calculated.

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).
9-49

Table 9-46. Time Spent at Home in Garage: Whole Population and Doers Only: Percentile Values

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent at home in garage (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

19

0

34

0

0

7

0

51

0

89

0

0

165

120

240

60

Time spent at home in garage (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

1

0

0

4

3

12

4

89

-

-

15

30

10

10

-

-

-

-

-

11

-

-

-

-

-

-

11

-

-

-

-

-

-

13

-

-

-

-

-

-

16

-

-

-

-

-

-

20

-

-

-

-

-

-

40

-

-

-

-

-

-

139

-

-

-

-

-

-

183

-

-

-

-

-

-

210

-

-

-

-

-

-

228

-

-

-

-

-

-

234

-

89

-

-

165

120

240

60

- For sample sizes less than 10, percentiles were not calculated.

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).

Table 9-47. Time Spent at Home: All Rooms Combined: Whole Population and Doers Only: Percentile Values

Age N Mean Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent at home in all rooms (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

1091

1047

971

951

873

876

819

0

0

0

0

0

0

0

391

63

66

284

0

0

0

631

377

342

402

0

117

165

742

651

640

621

420

370

375

786

705

727

716

631

575

510

943

915

852

810

758

751

645

1105 

1050

995

930

880

871

810

1258

1239

1120

1110

1005

1043

995

1440

1440

1232

1245

1175

1215

1170

1440

1440

1295

1354

1275

1314

1287

1440

1440

1354

1440

1374

1440

1419

1440

1440

1369

1440

1440

1440

1440

1440

1440

1410

1440

1440

1440

1440

Time spent at home in all rooms (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

62

116

117

355

486

459

473

1108

1065

979

957

893

889

833

630

370

30

150

190

40

85

633

399

288

352

335

141

206

658

495

551

451

389

300

321

751

674

650

634

541

441

433

821

715

746

720

655

590

525

956

923

857

810

765

758

660

1108

1050

1005

930

885

875

815

1259

1243

1120

1110

1009

1046

1000

1440

1440

1232

1245

1177

1218

1170

1440

1440

1296

1355

1275

1315

1288

1440

1440

1355

1440

1385

1440

1420

1440

1440

1369

1440

1440

1440

1440

1440

1440

1410

1440

1440

1440

1440

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).
9-50

Table 9-48. Time Spent in an Car: Whole Population and Doers Only: Percentile Values

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent in a car (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

8

10

20

20

20

15

15

40

49

60

50

60

55

55

90

107

98

90

117

102

99

155

171

151

126

155

146

150

195

208

246

163

221

185

254

249

220

336

187

272

212

302

321

235

390

215

620

630

900

380

Time spent in a car (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

35

68

73

227

317

286

364

2

5

4

4

1

1

2

5

8

4

4

2

3

9

7

10

4

5

2

5

10

10

10

8

7

5

5

10

14

15

10

10

10

10

17

20

30

24

25

20

20

30

40

58

42

45

40

40

60

73

85

65

88

82

75

105

159

147

118

150

127

122

180

203

186

141

180

163

193

210

218

323

181

267

202

279

275

227

363

197

327

300

338

334

235

390

215

620

630

900

380

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).

Table 9-49. Time Spent in a Truck (Pickup or Van): Whole Population and Doers Only: Percentile Values

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent in a truck (pickup or van) (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

14

0

15

15

25

0

0

31

30

45

59

90

0

52

124

60

95

153

150

42

81

201

114

110

181

190

110

90

955

245

240

352

445

Time spent in a truck (pickup or van) (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

1

5

15

34

69

62

70

110

20

10

1

1

5

5

-

-

10

2

4

5

5

-

-

10

4

6

5

5

-

-

10

8

10

5

10

-

-

11

10

10

7

11

-

-

15

16

15

15

22

-

-

30

30

30

35

54

-

-

53

59

65

89

115

-

-

188

117

110

180

170

-

-

434

207

124

185

213

-

-

746

222

151

258

238

-

-

851

233

186

299

304

110

90

955

245

240

352

445

- For sample sizes less than 10, percentiles were not calculated.

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).
9-51

Table 9-50. Time Spent in a Truck (Not Pickup or Van): Whole Population and Doers Only: Percentile Values

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent in a truck (not pickup or van) (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

19

0

0

1

0

0

105

95

95

250

90

Time spent in a truck (not pickup or van) (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

0

0

1

5

5

4

5

-

-

105

15

10

60

5

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

105

95

95

250

90

- For sample sizes less than 10, percentiles were not calculated.

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).

Table 9-51. Time Spent on a Bus: Whole Population and Doers Only: Percentile Values

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent on a bus (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

15

0

0

0

0

0

50

60

0

0

0

0

0

70

89

45

0

0

0

30

90

119

108

0

0

25

47

110

148

135

0

0

120

80

140

370

225

Time spent on a bus (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

0

0

2

14

115

130

41

-

-

30

15

5

7

10

-

-

-

16

5

10

12

-

-

-

16

6

10

14

-

-

-

18

14

10

20

-

-

-

21

17

15

25

-

-

-

30

25

30

30

-

-

-

33

43

54

60

-

-

-

49

67

71

100

-

-

-

67

90

101

135

-

-

-

74

107

131

175

-

-

-

77

120

159

193

-

-

-

79

122

175

209

-

-

120

80

140

370

225

- For sample sizes less than 10, percentiles were not calculated.

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).
9-52

Table 9-52. Time Spent on a Train: Whole Population and Doers Only: Percentile Values

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent on a train (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

4

25

0

0

0

0

0

60

65

0

120

5

480

15

140

Time spent on a train (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

1

0

1

1

1

1

10

65

-

120

5

480

15

10

-

-

-

-

-

-

11

-

-

-

-

-

-

11

-

-

-

-

-

-

12

-

-

-

-

-

-

15

-

-

-

-

-

-

56

-

-

-

-

-

-

60

-

-

-

-

-

-

94

-

-

-

-

-

-

122

-

-

-

-

-

-

131

-

-

-

-

-

-

136

-

-

-

-

-

-

138

65

-

120

5

480

15

140

- For sample sizes less than 10, percentiles were not calculated.

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).

Table 9-53. Time Spent on an Airplane: Whole Population and Doers Only: Percentile Values

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent on an airplane (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

245

480

Time spent on an airplane (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

0

0

0

0

0

2

3

-

-

-

-

-

80

15

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

80

15

- For sample sizes less than 10, percentiles were not calculated.

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).
9-53

Table 9-54. Time Spent on a Boat: Whole Population and Doers Only: Percentile Values

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Time spent on a boat (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

10

0

0

65

60

30

Time spent on a boat (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

0

1

0

0

1

1

1

-

10

-

-

65

60

30

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

10

-

-

65

60

30

- For sample sizes less than 10, percentiles were not calculated.

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).

Table 9-55. Total Time Spent Inside Vehicles: Whole Population and Doers Only: Percentile Values

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Total time spent inside vehicles (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

15

15

25

20

28

30

30

40

45

62

60

60

60

65

85

85

120

113

98

120

122

124

155

180

171

151

151

167

155

206

239

208

246

203

238

212

291

328

220

336

214

272

289

383

382

235

390

955

620

630

900

675

Total time spent inside vehicles (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

37

72

86

261

417

383

428

2

5

4

1

1

1

5

5

9

4

4

2

5

8

8

10

5

6

4

5

10

10

10

10

10

10

10

15

16

20

10

13

14

16

20

20

30

26

30

25

30

40

46

60

45

46

55

60

75

75

85

83

85

90

99

120

151

143

128

150

130

177

190

202

178

166

190

161

235

240

217

316

212

261

240

314

345

226

362

326

309

306

392

386

235

390

955

620

630

900

675

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).
9-54

Table 9-56. Time Spent Inside Grocery/Convenience Stores, Other Stores, and Malls: Whole Population and Doers

Only: Percentile Values

Age N Min

Percentiles

Max

1 2 5 10 25 50 75 90 95 98 99

Total time spent inside grocery/convenience stores, other stores, and malls (whole population) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

63

118

118

357

497

466

481

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

30

0

0

0

0

0

15

98

62

60

62

49

54

120

178

87

86

111

101

122

230

224

146

133

189

167

204

402

241

202

250

223

225

300

484

250

255

360

420

320

413

960

Total time spent inside grocery/convenience stores, other stores, and malls (DOERS ONLY) (min/day)

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

21

23

27

64

91

104

146

5

5

10

5

3

1

2

5

7

11

5

3

2

4

5

9

13

5

5

5

5

5

17

20

16

5

10

5

24

30

33

23

14

10

10

30

55

45

50

20

20

22

55

65

60

73

60

45

60

130

93

82

116

110

120

149

190

152

120

204

170

199

330

235

205

234

236

230

300

456

244

235

313

339

255

359

517

247

245

337

382

262

383

562

250

255

360

420

320

413

960

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).

Table 9-57. Average Time Spent Inside and Outside, By Age Category (min/day)

Age Category Average Indoor Minutes Average Outdoor Minutes Average Unclassified minutesa

0 to <1

1to < 2

2 to <3

3 to <6

6 to <11

11 to <16

16 to <21

1355

1341

1288

1275

1250

1260

1249

34

51

96

111

126

100

97

51

48

56

55

63

80

94

a

Includes time spent in vehicles or in activities that could not be assigned an indoor or outdoor location.

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).
9-55

Table 9-58. Statistics for 24-hour Cumulative Number of Minutes Spent with Smokers Present

Category Population Group N Mean Std.

Dev.

Std.

Error

Min

Percentiles

5 25 50 75 90 95 

Age (years) 1-4 155 366.6 324.5 26.06 5 30 90 273 570 825 1010 Age (years) 5-11 224 318.1 314 20.98 1 25 105 190 475 775 1050 Age (years) 12-17 256 245.8 243.6 15.23 1 10 60 165 360 595 774 

Source: EPA Analysis of source data used by Tsang and Klepeis (1996) (NHAPS database).
9-56

Table 9-59. Gender and Age Groups

Age Group Subgroup Sample Size Age Range

Adolescents

Males 98 12-17 years

Females 85 12-17 years

Childrena

Young males 145 6-8 years

Young females 124 6-8 years

Old males 156 9-11 years

Old females 160 9-11 years

a Children under the age of 6 are excluded for the present study (too few responses in CARB study).

Source: Funk et al., 1998.
9-57

Table 9-60. Assignment of At-Home Activities to Ventilation Levels for Children

Low Moderate

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

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

Outdoor 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

Source: Funk et al., 1998.
9-58

Table 9-61. Aggregate Time Spent (minutes/day) At-Home in Activity Groups by Adolescents and Childrena

Activity Group

Adolescents Children

Mean SD Mean SD

Low 789 230 823 153

Moderate 197 131 241b 136

High 1 11 3 17

Highparticipants

c 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 (i.e. doers).

Source: Funk et al., 1998.

Table 9-62. Comparison of Mean Time (minutes/day) Spent At-Home by Gendera (Adolescents)

Activity Group

Male Female

Mean SD Mean SD

Low 775 206 804 253

Moderate 181 126 241 134

High 2 16 0 0

Source: Funk et al., 1998.

Table 9-63. Comparison of Mean Time (minutes/day) Spent At-Home by Gender and Age for Childrena

Activity

Group

Males Females

6-8 Years 9-11 Years 6-8 Years 9-11 Years

Mean SD Mean SD Mean SD Mean SD

Low 806 134 860 157 828 155 803 162

Moderate 259 135 198 111 256 141 247 146

High 3 17 7 27 1 9 2 10

Highparticipants

b 77 59 70 54 68 11 30 23

a Time spent engaging in all activities embodied by Ve category (minutes/day) b Participants in high Ve activities (i.e. doers)

Source: Funk et al., 1998.
9-59

Table 9-64. Number of Person-Days/Individualsa for Children in CHADa Database

Age Group All Studies Californiab Cincinnatic NHAPS-Air NHAPS-Water

0 year 223/199 104 36/12 39 44

0-6 months 50 15/5

6-12 months 54 21/7

1 year 259/238 97 31/11 64 67

12-18 months 57

18-24 months 40

2 years 317/264 112 81/28 57 67

3 years 278/242 113 54/18 51 60

4 years 259/232 91 41/14 64 63

5 years 254/227 98 40/14 52 64

6 years 237/199 81 57/19 59 40

7 years 243/213 85 45/15 57 56

8 years 259/226 103 49/17 51 55

9 years 229/195 90 51/17 42 46

10 years 224/199 105 38/13 39 42

11 years 227/206 121 32/11 44 30

Total 3009/2640 1200 556/187 619 634

a CHAD - Consolidated Human Activity 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 1989 study.

The number of person-days of data are the same as the number of individuals for all studies except for the Cincinnati study. 

Since up to three days of activity pattern data were obtained from each participant in this study, the number of person-days of

data is approximately three times the number of individuals.

Source: Hubal et al., 2000.
9-60

Table 9-65. Number of Hours Per Day Children Spend in Various Microenvironments by Age

Age (years)

Average ± Std. Dev. (Percent of Children Reporting >0 Hours in Microenvironment)

Indoors at Home Outdoors at Home Indoors at School Outdoors at Park In Vehicle

0 19.6 ± 4.3 (99%) 1.4 ± 1.5 (20%) 3.5 ± 3.7 (2%) 1.6 ± 1.5 (9%) 1.2 ± 1.0 (65%)

1 19.5 ± 4.1 (99) 1.6 ± 1.3 (35) 3.4 ± 3.8 (5) 1.9 ± 2.7 (10) 1.1 ± 0.9 (66)

2 17.8 ± 4.3 (100) 2.0 ± 1.7 (46) 6.2 ± 3.3 (9) 2.0 ± 1.7 (17) 1.2 ± 1.5 (76)

3 18.0 ± 4.2 (100) 2.1 ± 1.8 (48) 5.7 ± 2.8 (14) 1.5 ± 0.9 (17) 1.4 ± 1.9 (73)

4 17.3 ± 4.3 (100) 2.4 ± 1.8 (42) 4.9 ± 3.2 (16) 2.3 ± 1.9 (20) 1.1 ± 0.8 (78)

5 16.3 ± 4.0 (99) 2.5 ± 2.1 (52) 5.4 ± 2.5 (39) 1.6 ± 1.5 (28) 1.3 ± 1.8 (80)

6 16.0 ± 4.2 (98) 2.6 ± 2.2 (48) 5.8 ± 2.2 (34) 2.1 ± 2.4 (32) 1.1 ± 0.8 (79)

7 15.5 ± 3.9 (99) 2.6 ± 2.0 (48) 6.3 ± 1.3 (40) 1.5 ± 1.0 (28) 1.1 ± 1.1 (77)

8 15.6 ± 4.1 (99) 2.1 ± 2.5 (44) 6.2 ± 1.1 (41) 2.2 ± 2.4 (37) 1.3 ± 2.1 (82)

9 15.2 ± 4.3 (99) 2.3 ± 2.8 (49) 6.0 ± 1.5 (39) 1.7 ± 1.5 (34) 1.2 ± 1.2 (76)

10 16.0 ± 4.4 (96) 1.7 ± 1.9 (40) 5.9 ± 1.5 (39) 2.2 ± 2.3 (40) 1.1 ± 1.1 (82)

11 14.9 ± 4.6 (98) 1.9 ± 2.3 (45) 5.9 ± 1.5 (41) 2.0 ± 1.7 (44) 1.6 ± 1.9 (74)

Source: Hubal et al., 2000.
9-61

Table 9-66. Average Number of Hours Per Day Children Spend Doing Various Macroactivities While Indoors at

Home

Age

(year)

Number of hours and Percentage of Children Reporting >0 Hours for Microenvironment/macroactivity)

Eat Sleep or Nap Shower or

Bathe

Play

Games

Watch TV or

Listen to Radio

Read, Write,

Homework

Think, Relax,

Passive

0 1.9 (96%) 12.6 (99%) 0.4 (44%) 4.3 (29%) 1.1 (9%) 0.4 (4%) 3.3 (62%)

1 1.5 (97) 12.1 (99) 0.5 (56) 3.9 (68) 1.8 (41) 0.6 (19) 2.3 (20)

2 1.3 (92) 11.5 (100) 0.5 (53) 2.5 (59) 2.1 (69) 0.6 (27) 1.4 (18)

3 1.2 (95) 11.3 (99) 0.4 (53) 2.6 (59) 2.6 (81) 0.8 (27) 1.0 (19)

4 1.1 (93) 10.9 (100) 0.5 (52) 2.6 (54) 2.5 (82) 0.7 (31) 1.1 (17)

5 1.1 (95) 10.5 (98) 0.5 (54) 2.0 (49) 2.3 (85) 0.8 (31) 1.2 (19)

6 1.1 (94) 10.4 (98) 0.4 (49) 1.9 (35) 2.3 (82) 0.9 (38) 1.1 (14)

7 1.0 (93) 9.9 (99) 0.4 (56) 2.1 (38) 2.5 (84) 0.9 (40) 0.6 (10)

8 0.9 (91) 10.0 (96) 0.4 (51) 2.0 (35) 2.7 (83) 1.0 (45) 0.7 (7)

9 0.9 (90) 9.7 (96) 0.5 (43) 1.7 (28) 3.1 (83) 1.0 (44) 0.9 (17)

10 1.0 (86) 9.6 (94) 0.4 (43) 1.7 (38) 3.5 (79) 1.5 (47) 0.6 (10)

11 0.9 (89) 9.3 (94) 0.4 (45) 1.9 (27) 3.1 (85) 1.1 (47) 0.6 (10)

Source: Hubal et al., 2000.
9-62

Table 9-67. Number of Hours Per Day Children Spend in Various Microenvironments by Age - Recast Into New

Standard Age Categories

Age

Category

Indoors at Home Outdoors at

Home

Indoors at

School

Outdoors at

Park

In Vehicle

mean

hr/day

%

doing

mean

hr/day

%

doing

mean

hr/day

%

doing

mean

hr/day

%

doing

mean

hr/day

%

doing

birth to <1

month

19.6 98% 1.7 21% 4.3 3% 1.3 3% 1.3 63%

1 to <3

months

20.9 100% 1.8 9% 0.2 3% 1.6 9% 1.3 27%

3 to <6

months

19.6 100% 0.8 8% 7.8 7% 1.3 6% 1.1 14%

6 to <12

months

19.1 99% 1.1 15% 7.6 8% 1.8 5% 1.3 14%

1 to <2

years

19.2 99% 1.4 34% 6.4 9% 1.5 5% 1.1 27%

2 to <3

years

18.2 99% 1.8 38% 6.8 12% 2.1 7% 1.3 28%

3 to <6

years

17.3 100% 1.9 43% 5.9 26% 1.6 10% 1.3 29%

6 to <11

years

15.7 99% 1.9 40% 6.5 44% 2.1 17% 1.1 29%

11 to <16

years

15.5 97% 1.7 30% 6.6 45% 2.6 15% 1.3 42%

16 to <21

years 

14.6 98% 1.4 20% 5.7 33% 3.1 10% 1.7 90%

Source: Based on data source used by Hubal et al., 2000. (CHAD Database)
9-63

Table 9-68. Number of Hours Per Day Children Spend in Various Macroactivities While Indoors at Home - Recast Into New Standard 

Age

Category

Eat Sleep or Nap Shower or Bathe Play Games

Watch

TV/Listen to

Radio

Read, Wri

Homewor

mean

hr/day

%

doing

mean

hr/day

%

doing

mean

hr/day

%

doing

mean

hr/day

%

doing

mean

hr/day

%

doing

mean

hr/day

do

birth to <1 month 2.2 98% 13.0 100% 0.5 41% 5.0 53% 1.3 8% 0.7 2

1 to <3 months 2.4 100% 14.8 100% 0.4 24% 0.7 6% 1.6 15% 0.0 03 to <6 months 2.0 100% 13.5 100% 0.5 9% 1.3 31% 1.0 21% 1.1 3

6 to <12 months 1.8 100% 12.9 100% 0.4 11% 1.1 30% 1.3 25% 0.5 4

1 to <2 years 1.7 99% 12.5 100% 0.5 21% 3.2 45% 1.8 52% 0.6 12 to <3 years 1.5 98% 12.0 100% 0.5 22% 2.6 45% 2.0 77% 0.6 13 to <6 years 1.4 99% 11.2 100% 0.5 38% 2.5 38% 2.3 86% 0.7 2

6 to <11 years 1.2 98% 10.2 100% 0.4 54% 2.0 28% 2.6 84% 1.0 4

11 to <16 years 1.1 94% 9.7 98% 0.4 50% 1.8 18% 3.0 85% 1.4 4

16 to <21 years 1.0 84% 8.9 98% 0.4 45% 1.9 5% 3.2 73% 2.2 3

Source: Based on data source used by Hubal et al., 2000. (CHAD Database)
9-64

Table 9-69. Number and percentage of respondents with children and those reporting outdoor playa activities in both

warm and cold weather

Source

Respondents with

children

Child playersa Child non players Warm

weather

playerb

Cold

weather

player

Player in

both

seasons

n n % n% n n %

SCS-II base 197 128 65.0 69 35.0 127 100 50.8

SCS-II

oversample

483 372 77.0 111 23.0 370 290 60.0

Total 680 500 73.5 180 26.5 497 390 57.4

a

 “Play” and “player” refer specifically to participation in outdoor play on bare dirt or mixed grass and dirt. b

 Does not include three “Don’t know/refused” responses regarding warm weather play.

Source: Wong et al. (2000)

Table 9-70. Play frequency and duration for all child players (from SCS-II data)

Statistic

Cold weather Warm weather

Frequency

(d/wk)

Duration

(hrs/d)

Total

(hrs/wk)

Frequency

(d/wk)

Duration

(hrs/d)

Total

(hrs/wk)

n 372 374 373 488 479 480

5th Percentile 111214

50th

Percentile

3 1 5 7 3 20

95th

Percentile

7 4 20 7 8 50

Source: Wong et al. (2000)
9-65

Table 9-71. Hand washing and bathing frequency for all child players (from SCS-II data)

Statistic

Cold weather Warm weather

Hand washing

(times/d)

Bathing

(times/wk)

Hand washing

(times/d)

Bathing

(times/wk)

n 329 388 433 494

5th Percentile 2 2 2 3

50th Percentile 4 7 4 7

95th Percentile 10 10 12 14

Source: Wong et al. (2000)

Table 9-72 NHAPS and SCS-II play durationa

 comparison

Data Source

Mean play duration

(min/d)

O2 testb

Cold weather Warm weather Total

NHAPS 114 109 223 p<0.0001

SCS-II 102 206 308

a

 Selected previous day activities in NHAPS, average day outdoor play on bare dirt or mixed grass and dirt in SCSII.

b

 2x2 Chi-square test for contingency between NHAPS and SCS-II.

Source: Wong et al. (2000)
9-66

Table 9-73. NHAPS and SCS-II hand wash frequency comparison

Data

Source

Season

Percentb

 reporting frequency (times/d) of:

O2 testc

0 1-2 3-5 6-9 10-19 20-29 30+ “Don’t

know”

NHAPS cold 3 18 51 17 7 1 1 3

p = 0.06 SCS-II cold 1 16 50 11 7 1 0 15

NHAPS warm 3 18 51 15 7 2 1 4

p = 0.001 SCS-II warm 0 12 46 16 10 1 0 13

a

 Selected previous day activities in NHAPS, average day outdoor play on bare dirt or mixed grass and dirt in SCSII.

b

 Results are reported as percentage of total for clarity. Incidence data were used in statistical tests. c

 2x2 Chi-square test for contingency between NHAPS and SCS-II.

Source: Wong et al., 2000

Table 9-74. Summary of Activity Pattern Studies

Summary of Activity Patterns Studies

Study Age Groups

(yrs)

Sample Size Population Activities

Timmer (1985) 3-5, 6-8, 9-11, 12-

14, 15-17

922 National 18 microenvironments

Robinson & Thomas (1991) 12-adults 1,762

(California)

2,762 (national)

California and

National

16 microenvironments

Wiley (1991)* 0-2, 3-5, 6-8, 9-11 1,200 California 10 microenvironments

Tsang & Kleipeis (1996)* 1-4, 5-11, 12-17 Varies with age

groups and

activities

U.S. National 23 microenvironments

Funk (1998) 6-11, 12-17 768 California Activities grouped

into low, medium, and

high ventilation levels

Hubal (2000)* 0, 1, 2, 3, 4, 5, 6, 7,

8, 9, 10, 11

2,640 Based on Wiley

(1991), Johnson

(1989), and Tsang

& Kleipeis (1996)

Activities grouped

into indoors at home,

indoors at school,

outdoors at home,

outdoors at part, and

in vehicle

*These studies were re-analyzed by obtaining the source data and recasting it to fit the standardized age categories used in this

Handbook.
9-67

Table 9-75. Summary of Mean Time Spent Indoors and Outdoors from Several Studies

Age (years) Time Indoors

(hours/day)1

Time Outdoors

(hours/day)1

Study

3-5 years

6-8 years

9-11 years

12-14 years

15-17 years

19

20

20

20

19

2.8 (national)

2.2

1.8

1.8

1.9

Timmer et al., 1985

See Table 9-3

birth to <1 month

1 to <3 months

3 to <6 months

6 to <12 months

1 to <2 years

2 to <3 years

3 to <6 years

6 to <11 years

11 years

24

24

23

22

18

19

19

19

19

0

0

1

2

6

5

5

5

5

Wiley et al., 1991

(EPA Analysis 

of source data)

See Table 9-15

0 to <1 year

1 to <2 years

2 to <3 years

3 to <6 years

6 to <11 years

11to <16 years

16 to <21 years

23

22

21

21

21

21

21

1

1

2

2

2

2

1

Tsang and Kleipeis, 1996

(EPA Analysis 

of source data)

See Table 9-57

1 Mean of weekday and weekend rounded up to two significant figures, where applicable.

Standardized age groupings are shown in bold.
9-68

Table 9-76. Summary of Recommended Values for Activity Factors

Type Age Group Mean

(min/day)

Source

Time Indoors (at residence) 0 to <1 year

1to < 2 years

2 to <3 years

3 to <6 years

6 to <11 years

11 to <16 years

16 to <21 years

1108

1065

979

957

893

889

833

Tsang and Kleipeis (1996)

(EPA Analysis of source data)

Means of doers from Table 9-47, see table for

percentiles.

Time Indoors (total) birth to <1 month

1 to <3 months

3 to <6 months

6 to <12 months

1 to <2 years

2 to <3 years

3 to <6 years

6 to <11 years

1440

1431

1414

1301

1132

1112

1128

1164

Wiley et al., 1991

(EPA Analysis of source data)

Average of means for boys and girls from Table 9-

15

11to <16 years

16 to <21 years

1260

1249

Tsang and Kleipeis, 1996

(EPA Analysis of source data)

Means from Table 9-57

Time Outdoors birth to <1 month

1 to <3 months

3 to <6 months

6 to <12 months

1 to <2 years

2 to <3 years

3 to <6 years

6 to <11 years

0

8

26

139

307

328

311

275

Wiley et al., 1991

(EPA Analysis of source data)

Average of means for boys and girls from Table 9-

15

11to <16 years

16 to <21 years

100

97

Tsang and Kleipeis, 1996

(EPA Analysis of source data)

Means from Table 9-57

Showering birth to <1year

1 to <2 years

2 to <3 years

3 to <6 years

6 to <11 years

11to <16 years

16 to <21 years

1

20

22

17

18

18

20

Tsang and Kleipeis, 1996

(EPA Analysis of source data)

Means for doers Table 9-19, see table for percentiles

Bathing birth to <1 year

1 to <2 years

2 to <3 years

3 to <6 years

6 to <11 years

11to <16 years

16 to <21 years

19

23

23

24

24

25

33

Tsang and Kleipeis, 1996

(EPA Analysis of source data)

Means for doers from Table 9-21, see table for

percentiles

Playing on Sand/Gravel 0 to <1 years

1to < 2 years

2 to <3 years

3 to <6 years

6 to <11 years

11 to <16 years

16 to <21 years

18

43

60

65

73

75

113

Tsang and Kleipeis, 1996

(EPA Analysis of source data)

Means for doers from Table 9-26, see table for

percentiles
Type Age Group Mean

(min/day)

Source

9-69

Playing on Grass 0 to <1 years

1to < 2 years

2 to <3 years

3 to <6 years

6 to <11 years

11 to <16 years

16 to <21 years

72

73

82

106

85

79

60

Tsang and Kleipeis, 1996

(EPA Analysis of source data)

Means for doers from Table 9-26, see table for

percentiles

Playing on Dirt 0 to <1 years

1to < 2 years

2 to <3 years

3 to <6 years

6 to <11 years

11 to <16 years

16 to <21 years

33

56

79

67

75

52

30

Tsang and Kleipeis, 1996

(EPA Analysis of source data)

Means for doers from Table 9-26, see table for

percentiles

Type Age Group Mean

(Min/month)

Source

Swimming 0 to <1 years

1to < 2 years

2 to <3 years

3 to <6 years

6 to <11 years

11 to <16 years

16 to <21 years

313

251

636

946

868

667

868

Tsang and Kleipeis, 1996

(EPA Analysis of source data)

Means for doers from Table 9-28, see table for

percentiles
9-70

Table 9-77. Confidence in Activity Patterns Recommendations

Considerations Rationale Rating

TIME SPENT INDOORS VS. OUTDOORS

Study Elements

• Level of peer review The original studies received a high level of peer review; re-analysis of source data was not peer-review Low e

• Accessibility The studies are widely available to the public. High

• Reproducibility The reproducibility of these studies is left to question. Evidence has shown that activities have tended to 

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

data were reanalyzed in the same manner the results are expected to be the same.

Medium

• Focus on factor of interest The studies focused on general activity patterns. High

• Data pertinent to US The studies focused on the U.S. population. High

• Primary data Data were collected via questionnaires and interviews. High

• Currency The studies were published in 1985, 1991, and 1996. Medium

• Adequacy of data collection period Timmer: Households were sampled 4 times during 3 month intervals from February to December, 1981.

NHAPS: data were collected in a single telephone interview and are based on one day of activity.

Medium

• Validity of approach A 24 hour or real time recall diary method was used to collect data. High

• Study size Timmer: The sample population was 922 children between the ages of 3-17 years old. NHAPS: The samp

size was 2,100 individuals under the age of 21.

High

• Representativeness of the population The study focused on activities of children. High

• Characterization of variability Variability was characterized by age, gender, and day of the week; location of activities and various age

categories for children.

Medium

• Lack of bias in study design (high

rating is desirable)

Biases noted were sampled during time when children were in school (activities during vacation time are 

represented); activities in the 1980's and 1990's may be different than they are now.

Medium

• Measurement error Measurement or recording error may occur since the diaries were based on recall (in most cases a 24 hou

recall).

Medium

Other Elements

• Number of studies 3 High

• Agreement between researchers Difficult to compare due to varying categories of activities and the unique age distributions found within 

study.

Not Ranked

Overall Rating Medium
9-71

Table 9-77 Confidence in Activity Patterns Recommendations (cont’d)

Considerations Rationale Rating

TIME SPENT SHOWERING

Study Elements

• Level of peer review The original study received high level of peer review. The re-analysis of the NHAPS data to conform to t

standardized age categories was not peer-reviewed.

Low

• Accessibility Raw data are available to the public. High

• Reproducibility Results are reproducible. High

• Focus on factor of interest The study focused specifically focused on time spent showering. High

• Data pertinent to US The study focused on the U.S. general population. High

• Primary data The study was based on primary data. High

• Currency The study was published in 1996. Medium

• Adequacy of data collection period The data were collected between October 1992 and September 1994. Medium

• 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 socioeconomi

status for various U.S. subgroups.

High

• Study size Study consisted of 9,386 total participants consisting of all ages; 2100 respondents ages 0 to 20 years old

this category

Medium-Low

• Representativeness of the population The data were representative of the U.S. population. High

• Characterization of variability The study provides a distribution on showering duration. High

• Lack of bias in study design (high

rating is desirable)

The study includes distributions for showering duration. Study is based on short-term data. High

• Measurement error Measurement or recording error may occur because diaries are based on 24-hour recall. Medium

Other Elements

• Number of studies One; the study was a national study. Low

• Agreement between researchers The recommendation is based on the data (presented in ranges) from only one study (NHAPS), but it is a

widely accepted study. The recommended value was selected based on professional judgment because th

data were presented as a range (10-20 minutes).

Low-Medium

Overall Rating Medium
9-72

Table 9-77. Confidence in Activity Patterns Recommendations (cont’d)

Considerations Rationale Rating

SHOWER FREQUENCY

Study Elements

• Level of peer review The original study received high level of peer review. The re-analysis of the NHAPS data to conform to 

standardized age categories was not peer-reviewed. 

Low

• Accessibility Raw data are available to the public. High

• Reproducibility Results can be reproduced or methodology can be followed and evaluated provided comparable economi

and social conditions exists.

High

• Focus on factor of interest The survey collected information on duration and frequency of showering. High

• Data pertinent to US The data represents the U.S. population High

• Primary data The study was based on primary data. High

• Currency The study was published in 1996. Medium

• Adequacy of data collection period The data were collected between October 1992 and September 1994. Medium

• 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 socioeconom

status for various U.S. subgroups. Responses were weighted according to this demographic data.

High

• Study size The study consisted of 9,386 total participants consisting of all age groups; 1200 respondents ages 0-20

years old for this category.

Medium-low

• Representativeness of the population Studies were based on the U.S. population. High

• Characterization of variabilityThe study provided data that varied across geographic region, race, gender, employment status, education

level, day of the week, seasonal conditions, and medical conditions of respondent..

High

• Lack of bias in study design (high

rating is desirable)

Study is based on short term data.. Medium

• Measurement error Measurement or recording error may occur because diaries were based on 24-hour recall. Medium

Other Elements

• Number of studies One; the study was based on one, primary, national study. Low

• Agreement between researchers Recommendation was based on only one study. Not Ranked

Overall Rating Medium

Table 9-77. Confidence in Activity Patterns Recommendations (cont’d)

Considerations Rationale Rating

TIME SPENT SWIMMING

Study Elements

• Level of peer review The original study received high level of peer review. The re-analysis of the NHAPS data to conform to th

standardized age categories was not peer-reviewed. 

Low
Table 9-77. Confidence in Activity Patterns Recommendations (cont’d)

Considerations Rationale Rating

9-73

• Accessibility Raw data are available to the public. High

• Reproducibility Results can be reproduced or methodology can be followed and evaluated provided comparable economic

and social conditions exists.

High

• Focus on factor of interestThe survey collected information on duration and frequency of selected activities and time spent in selecte

micro-environments. It only addresses time swimming at a swimming pool.

Medium

• Data pertinent to US The data represents the U.S. population High

• Primary data The study was based on primary data. High

• Currency The study was published in 1996. Medium

• Adequacy of data collection period The data were collected between October 1992 and September 1994. Medium

• 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. Responses were weighted according to this demographic data.

High

• Study size The study consisted of 9,386 total participants consisting of all age groups; 273 respondents aged 0-20 ye

old swam at least once.

Low

• Representativeness of the

population

Studies were based on the U.S. population. High

• Characterization of variability The study provided data that varied across geographic region, race, gender, employment status, education

level, day of the week, seasonal conditions, and medical conditions of respondent..

High

• Lack of bias in study design (high

rating is desirable)

The study includes distributions for swimming duration. Study is based on short term data. Medium

• Measurement error Measurement or recording error may occur because diaries were based on 24-hour recall. Medium

Other Elements

• Number of studies One; the study was based on one, primary, national study. Low

• Agreement between researchers Recommendation was based on only one study. Not Ranked

Overall Rating Medium

Table 9- 77. Confidence in Activity Patterns Recommendations (cont’d)

Considerations Rationale Rating

TIME SPENT PLAYING ON SAND, GRAVEL, OR GRASS

Study Elements

• Level of peer review The original study received high level of peer review. The re-analysis of the NHAPS data to conform to t

standardized age categories was not peer-reviewed. 

Low

• Accessibility Raw data are available to the public. High

• Reproducibility Results can be reproduced or methodology can be followed and

evaluated provided comparable economic and social conditions exists.

High
Table 9- 77. Confidence in Activity Patterns Recommendations (cont’d)

Considerations Rationale Rating

9-74

• Focus on factor of

interest

The survey collected information on duration and frequency of selected

activities and time spent in selected micro-environments.

High

• Data pertinent to US The data represents the U.S. population. High

• Primary data The study was based on primary data. High

• Currency The study was published in 1996. Medium

• Adequacy of data

collection period

The data were collected between October 1992 and September 1994. Medium

• 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. Responses were weighted according to this

demographic data.

High

• Study size The study consisted of 9,386 total participants consisting of all age

groups; 2100 respondents aged 0-20 years old for this category.

Mediumlow

• Representativeness of 

the population

The studies were based on the U.S. population. High

• Characterization of

variability

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..

High

• Lack of bias in study

design (high rating is

desirable)

The study includes distributions for bathing duration. Study is based on

short-term data.

Medium

• Measurement error Measurement or recording error may occur because diaries were based

on 24-hour recall.

Medium

Other Elements

• Number of studies One; the study was based on one, primary, national study. Low

• Agreement between

researchers

Recommendation was based on only one study. Recommendations

based on 50% time spent playing on grass.

Not

Ranked

Overall Rating Medium