### TABLE OF CONTENTS

7. INHALATION ROUTE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1 7.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1 7.2 INHALATION RATE STUDIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1 7.2.1 Linn et al., 1992 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1 7.2.2 Spier et al., 1992 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2 7.2.3 Adams, 1993 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-3 7.2.4 Layton, 1993 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5 7.2.5 Rusconi et al., 1994 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7 7.2.6 Lordo et al., 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-9 7.3 RECOMMENDATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-11 7.4 REFERENCES FOR CHAPTER 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-12

APPENDIX 7A

VENTILATION DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-38

### LIST OF TABLES

Table 7-1. Calibration And Field Protocol s For Self-monitoring of Activities Grouped by Subject Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-13 Table 7-2. Subject Panel Inhalation Rates by Mean VR, Upper Percentiles, And Self-estimated Breathing Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-13 Table 7-3. Distribution of Predicted Intake Rates by Location And Activity Levels For Elementary And High School Students . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14 Table 7-4. Average Hours Spent Per Day in a Given Location and Activity Level For Elementary and High School Students . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-14 Table 7-5. Distribution Patterns of Daily I nhalation Rates For Elementary (EL) And High School (HS) Students Grouped by Activity Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-15 Table 7-6. Summary of Average Inhalation Rates (m 3 

### /hr) by Age Group And Activity Levels for Laboratory Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-16 Table 7-7. Summary of Average Inhalation Rates (m 3 

### /hr) by Age Group And Activity Levels in Field Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-17 Table 7-8. Comparisons of Estimated Basal Metabolic Rates (BMR) With Average Food-energy Intakes (EFD) For Individuals Sampled in The 1977-78 NFCS . . . . . . . . . . . . . . . . . 7-18 Table 7-9. Daily Inhalation Rates Calculated From Food-energy Intakes . . . . . . . . . . . . . . . 7-19 Table 7-10. Daily Inhalation Rates Obtained From The Ratios Of Total Energy Expenditure to Basal Metabolic Rate (BMR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-20 Table 7-11. Inhalation Rates For Short-term Exposures . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-21 Table 7-12. Mean, Median, and SD of Respirat ory Rate According to Waking or Sleeping in 618 Infants and Children Grouped in Classes of Age . . . . . . . . . . . . . . . . . . . . . . . . . 7-22 Table 7-13. Descriptive Statistics for Daily Average Ventilation Rate (L/min) in Males , by Age Category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-24 Table 7-14. Descriptive Statistics for Daily Average Ventilation Rate (L/min) in Females , by Age Category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-25 Table 7-15. Average Time Spent Per Day Performing Activities Within Specified Intensity Categories, and Average Ventilation Rates Associated With These Activity Categories, for Males According to Age Category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-26 Table 7-16. Average Time Spent Per Day Performing Activities Within Specified Intensity Categories, and Average Ventilation Rates Associated With These Activity Categories, for Females According to Age Category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-29 Table 7-17. Descriptive Statistics for Daily Average Ventilation Rate (m 3 

### /day) in Males , by Age Category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-32 Table 7-18. Descriptive Statistics for Daily Average Ventilation Rate (m 3 

### /day) in Females , by Age Category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-33 Table 7-19. Descriptive Statistics for Duration of Time (hr/day) Spent Performing Activities Within the Specified Activity Category, by Age and Gender Categories

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-34 Table 7-20. Confidence in Inhalation Rate Recommendations . . . . . . . . . . . . . . . . . . . . . . . 7-36 Table 7-21. Summary of Recommended Values For Inhalation . . . . . . . . . . . . . . . . . . . . . . 7-37

### LIST OF FIGURES
Figure 7-1. 5th, 10th, 25th, 50th, 75th, 90th, a nd 95th Smoothed Centiles by Age in Awake Subjects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-23 Figure 7-2. 5th, 10th, 25th, 50th, 75th, 90th, a nd 95th Smoothed Centiles by Age in Asleep Subjects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-23

### 7-1 

## 7. INHALATION ROUTE 1
2 

## 7.1 INTRODUCTION 3 This chapter presents data and recommendations for inhalation rates that can be used to 4 assess children’s exposure to contaminants in air. Inhalation rates vary with both size and 5 activity level, both of which influence oxygen consumption. Infants and young children have a 6 higher resting metabolic rate and rate of oxygen consumption per unit body weight than do 7 adults because they have a larger cooling surface per unit body weight and because they are 8 growing rapidly. The oxygen consumption of a re sting infant aged between one week and one 9 year is 7 mL/kg body weight per minute. The rate for an adult under the same conditions is 3-5 10 mL/kg per minute (WHO, 1986). Thus, while on an absolute basis, greater amounts of air and 11 pollutants are inhaled by adults than children per similar time periods, on a body-weight basis, 12 the volume of air passing through the lungs of a resting infant is twice that of a resting adult 13
under the same conditions. The recommended inhalation rates for children are summarized in 14
Section 7.3. 15
16 

## 7.2 INHALATION RATE STUDIES 17 7.2.1 Linn et al., 1992 18 Linn et al. (1992) conducted a study that estimated the inhalation rates for "high-risk" 19 subpopulation groups exposed to ozone in their daily activities in the Los Angeles area. The 20 population surveyed consisted of several panels of both adults and children. The panels 21 consisting of children included Panel 2 : 17 healthy elementary school students (5 males and 12 22 females, ages 10-12 years); Panel 3 : 19 healthy high school students (7 males and 12 females, 23 ages 13-17 years); Panel 6 : 13 young asthmatics (7 males and 6 females, ages 11-16 years). 24 An initial calibration test was conducted, followed by a training session. Finally, a field 25 study that involved the subjects collecting their own heart rate and diary data was conducted. 26 During the calibration tests, ventilation rate (VR), breathing rate, and heart rate (HR) were 27 measured simultaneously at each exercise level. From the calibration data an equation was 28 developed using linear regression analysis to predict VR from measured HR. 29 In the field study, each subject recorded in diaries their daily activities, change in 30 locations (indoors, outdoors, or in a vehicl e), self-estimated breathing rates during each 31

### 7-2 activity/location, and time spent at each activity/location. Healthy subjects recorded their HR 1 once every 60 seconds using a Heart Watch, an automated system consisting of a transmitter and 2 receiver worn on the body. Asthmatic subjects recorded their diary information once every hour. 3 Subjective breathing rates were defined as slow (walking at their normal pace), medium (faster 4 than normal walking), and fast (running or similarl y strenuous exercise). Table 7-1 presents the 5 calibration and field protocols for self-monitoring of activities for each subject panel. 6 Table 7-2 presents the mean, 99 th 

### percentile, and mean VR at each subjective activity 7 level (slow, medium, fast). The mean and 99th percentile VR were derived from all HR 8 recordings that appeared to be valid, without considering the diary data. Each of the three 9 activity levels was determined from both the concurrent diary data and HR recordings by direct 10 calculation or regression. The authors reported that the diary data showed that on a typical day, 11 most individuals spent most of their time indoors at slow activity level. During slow activity, 12 asthmatic subjects had higher VRs than healthy subjects (Table 7-2). The authors also reported 13 that in every panel the predicted VR correlated significantly with the subjective estimates of 14 activity levels. 15 A limitation of this study is that calibration data may overestimate the predictive power 16 of HR during actual field monitoring. The wide variety of exercises in everyday activities may 17 result in greater variation of the VR-HR relationship than was calibrated. Another limitation is 18 the small sample size of each subpopulation surveyed. An advantage of this study is that diary 19 data can provide rough estimates of ventilation patterns which are useful in exposure 20 assessments. Another advantage is that inhalation rates were presented for both healthy and 21
asthmatic children. 22
23 7.2.2 Spier et al., 1992 24 Spier et al. (1992) investigated the activity patterns of 17 elementary school students (10- 25 12 years old) and 19 high school students (13-17 y ears old) in suburban Los Angeles from late 26 September to October (oxidant pollution season). Calibration tests were conducted in supervised 27 outdoor exercise sessions. The exercise sessions consisted of 5 minutes each of rest, slow 28 walking, jogging, and fast walking. HR and VR we re measured during the last 2 minutes of each 29 exercise. Individual VR and HR relationships for each individual were determined by fitting a 30 regression line to HR values and log VR values. Each subject recorded their daily activities, 31

### 7-3 change in location, and breathing rates in diaries for 3 consecutive days. Self-estimated 1 breathing rates were recorded as slow (slow walk ing), medium (walking faster than normal), and 2 fast (running). HR was recorded once per minute during the 3 days using a Heart Watch. 3 VR values for each self-estimated breathing rate and activity type were estimated from the 4 HR recordings by employing the VR and HR equation obtained from the calibration tests. 5 The data presented in Table 7-3 represent HR distribution patterns and corresponding 6 predicted VR for each age group during hours spent awake. At the same self-reported activity 7 levels for both age groups, inhalation rates were higher for outdoor activities than for indoor 8 activities. The total number of hours spent indoors was higher for high school students 9 (21.2 hours) than for elementary school stude nts (19.6 hours). The converse was true for 10 outdoor activities: 2.7 hours for high school students and 4.4 hours for elementary school 11 students (Table 7-4). Based on the data presented in Tables 7-3 and 7-4, the average activity12 specific inhalation rates for elementary sc hool students (10-12 years old) and high school 13 students (13-17 years old) were calculated and are presented in Table 7-5. For elementary 14 school students, the average daily inhalation rates (based on indoor and outdoor locations) are 15
15.8 m 3 

### /day for light activities, 4.6 m 3 

### /day for moderate activities, and 1.0 m 3 

### /day for heavy 16 activities. For high school students the daily inhalation rates for light, moderate, and heavy 17
activities are estimated to be 16.4 m 3 

### /day, 3.0 m 3 

### /day, and 0.6 m 3 

### /day, respectively (Table 7-5). 18 A limitation of this study is the small sample size. The results may not be representative 19 of all children in these age groups. Another limita tion is that the accuracy of the self-estimated 20 breathing rates reported by younger age groups is uncertain. This may affect the validity of the 21 data set generated. An advantage of this study is that inhalation rates were determined for 22 children and adolescents. These data are useful in estimating exposure for the younger 23 population. 24
25 7.2.3 Adams, 1993 26 Adams (1993) conducted research to accomplish two main objectives: (1) identification 27 of mean and ranges of inhalation rates for various age/gender cohorts and specific activities, and 28 (2) derivation of simple linear and multiple regression equations that could be used to predict 29 inhalation rates through other measured variab les: breathing frequency and oxygen consumption. 30 A total of 160 subjects participated in the primary study. For children, there were two age- 31

### 7-4 

### BSA Height (0.425) Weight (0.425) 71.84 =× × (7-1) dependent groups: children 6 to 12.9 years old and adolescents 13 to18.9 years old. An 1 additional 40 children from 6 to 12 years old and 12 young children from 3 to 5 years old were 2 identified as subjects for pilot testing purposes. 3 Resting protocols conducted in the laboratory for all age groups consisted of three phases 4 (25 minutes each) of lying, sitting, and standing. The phases were categorized as resting and 5 sedentary activities. Two active protocols— moderate (walking) and heavy (jogging/ running) 6 phases— were performed on a treadmill over a progressive continuum of intensity levels made 7 up of 6-minute intervals at three speeds ranging fr om slow to moderately fast. All protocols 8 involved measuring ventilation rate (VR), h eart rate (HR), breathing frequency, and oxygen 9 consumption. Measurements were taken in the last 5 minutes of each phase of the resting 10 protocol and the last 3 minutes of the 6-minute intervals at each speed designated in the active 11 protocols. 12 In the field, all children completed spontaneous play protocols; the older adolescent 13 population (16-18 years) completed car driving and riding, car maintenance (males), and 14 housework (females) protocols. 15 During all activities in either the laboratory or field protocols, VR for the children’s 16 group revealed no significant gender differences. Therefore, VR data presented in Appendix 17 Tables 7A-1 and 7A-2 were categorized by ac tivity type (lying, sitting, standing, walking, and 18 running) for young children and children without regard to gender. These categorized data from 19 the appendix tables are summarized as inhalation rates in Tables 7-6 and 7-7. The laboratory 20 protocols are shown in Table 7-6. Table 7-7 pr esents the mean inhalation rates by group and for 21 moderate activity levels in field protocols. Da ta were not provided for the light and sedentary 22 activities because the group did not perform for this protocol or the number of subjects was too 23 small for appropriate comparisons. Accurate predictions of inhalation rates across all population 24 groups and activity types were obtained by including body surface area (BSA), HR, and 25 breathing frequency in multiple regression analysis (Adams, 1993). Adams (1993) calculated 26 BSA from measured height and weight using the equation: 27
28

29

### 7-5 A limitation associated with this study is that the population does not represent the 1 general U.S. population. Also, the classificati on of activity types (i.e., laboratory and field 2 protocols) into activity levels may bias the inhalation rates obtained for various age/gender 3 cohorts. The estimated rates were based on short-term data and may not reflect long-term 4 patterns. 5
6 7.2.4 Layton, 1993 7 Layton (1993) presented a new method for estimating metabolically consistent inhalation 8 rates for use in quantitative dose assessments of airborne radionuclides. Generally, the approach 9 for estimating the breathing rate for a specified time frame was to calculate a time-weighted10 average of ventilation rates associated with physical activities of varying durations. However, in 11 this study, breathing rates were calculated on the basis of oxygen consumption associated with 12 energy expenditures for short (hours) and long (weeks and months) periods of time, using the 13 following general equation to calculate energy-dependent inhalation rates: 14
15

16 V E E H VQ = ×× 

### (7-2)

where: 17
V E 

### = ventilation rate (L/min or m 3 

### /hr); 18 E = energy expenditure rate; [kilojoules/minute (KJ/min) or 19 megajoules/hour (MJ/hr)]; 20 H = volume of oxygen [at standard temperature and pressure, dry air 21 consumed in the production of 1 KJ of energy expended (L/KJ or 22

m 3 

### /MJ)]; and 23 VQ = ventilatory equivalent (ratio of minute volume (L/min) to oxygen 24 uptake (L/min)); unitless. 25
26 Layton used two alternative approaches to estimate daily chronic (long term) inhalation 27 rates for different age/gender cohorts of the U.S. population using this methodology. 28
29

### 7-6 7.2.4.1. First Approach 1 Inhalation rates were estimated by multiplying average daily food energy intakes for 2 different age/gender cohorts, volume of oxygen (H), and ventilatory equivalent (VQ), as shown 3 in the equation above. The average food energy intake data (Table 7-8) are based on 4 approximately 30,000 individuals and were obt ained from the USDA 1977-78 Nationwide Food 5 Consumption Survey (USDA-NFCS). The food energy intakes were adjusted upwards by a 6 constant factor of 1.2 for all individuals 9 year s and older. This factor compensated for a 7
consistent bias in USDA-NFCS that was attri buted to under-reporting of the foods consumed or 8 the methods used to ascertain dietary intakes. Layton used a weighted average oxygen uptake of 9
0.05 L O 2 

### /KJ which was determined from data reported in the 1977-78 USDA-NFCS and the 10 second National Health and Nutrition Examination Survey (NHANES II). The survey sample 11 for NHANES II was approximately 20,000 participants. A VQ of 27 used in the calculations 12 was calculated as the geometric mean of VQ data that were obtained from several studies. 13 The inhalation rate estimation techniques are shown in footnote (a) of Table 7-9. 14 Table 7-9 presents the daily inhalation rate for each age/gender cohort. The highest daily 15
inhalation rates were 10 m 3 

### /day for children between the ages of 6 and 8 years, 17 m 3 

### /day for 16 males between 15 and 18 years, and 13 m 3 

### /day for females between 9 and 11 years. Inhalation 17 rates were also calculated for active and inactive periods for the various age/gender cohorts. 18 The inhalation rate for inactive periods was estimated by multiplying the basal metabolic 19 rate (BMR) times H times VQ. BMR was defined as "the minimum amount of energy required 20 to support basic cellular respiration while at re st and not actively digesting food" (Layton, 1993). 21 The inhalation rate for active periods was calculated by multiplying the inactive inhalation rate 22 by the ratio of the rate of energy expenditure during active hours to the estimated BMR. This 23 ratio is presented as F in Table 7-9. These data for active and inactive inhalation rates are also 24 presented in Table 7-9. For children, inactive and active inhalation rates ranged between 2.35 25
and 5.95 m 3 

### /day and 6.35 to 13.09 m 3 

### /day, respectively. 26
27
7.2.4.2. Second Approach 28 Inhalation rates were calculated as the product of the BMR of the population cohorts, the 29 ratio of total daily energy expenditure to daily BMR, H, and VQ. The BMR data obtained from 30 the literature were statistically analyzed, and regression equations were developed to predict 31

### 7-7 BMR from body weights of various age/gender cohorts . The statistical data used to develop the 1 regression equations are presented in Appendix Ta ble 7A-3. The data obtained from the second 2 approach are presented in Table 7-10. Inhalation rates for children (6 months - 10 years) ranged 3
from 7.3 to 9.3 m 3 

### /day for male and 5.6 to 8.6 m 3 

### /day for female children; for older children (10 4 to 18 years), inhalation rates were 15 m 3 

### /day for males and 12 m 3 

### /day for females. These rates 5 are similar to the daily inhalation rates obtained using the first approach. Also, the inactive 6 inhalation rates obtained from the first approach are lower than the inhalation rates obtained 7 using the second approach. This may be attributed to the BMR multiplier employed in the 8 equation of the second approach to calculate inhalation rates. 9 Inhalation rates were also obtained for short-term exposures for various age/gender 10 cohorts and five energy-expenditure categories (rest, sedentary, light, moderate, and heavy). 11 BMRs were multiplied by the product of the metabolic equivalent, H, and VQ. The data 12 obtained for short term exposures are presented in Table 7-11. 13 This study obtains similar results using three different approaches. The major strengths 14 of this study are that it estimates inhalation rates in different age groups and that the populations 15 are large. Explanations for differences in results due to metabolic measurements, reported diet, 16 or activity patterns are supported by observations reported by other investigators in other studies. 17 Major limitations of this study are (1) the estimated activity pattern levels are somewhat 18 subjective; (2) the explanation that activity pattern differences are responsible for the lower level 19 obtained with the metabolic approach (25 %) compared to the activity pattern approach is not 20 well supported by the data; and (3) different populations were used in each approach, which may 21
have introduced error. 22
23 7.2.5 Rusconi et al., 1994 24 Rusconi et al. (1994) examined a large number of infants and children in order to 25 determine the reference values for respiratory rate in children aged 15 days to 3 years. Previous 26 discrepancies in methodologies and results, and lack of age-related reference values for the first 27 years of life prompted the investigators to obtain normal reference values for respiratory rate 28 from a sufficient number of subjects. They assessed 618 infants and children (336 males and 29 282 females) aged 15 days to 3 years old who di d not have respiratory infections or any severe 30

### 7-8 disease. Of the 618, a total of 309 were in good health and in day care centers, while the 1 remaining 309 were seen in hospitals or outpatients. 2 Respiratory rates were recorded twice, 30 to 60 minutes apart, listening to breath sounds 3 for 60 seconds with a stethoscope, when the child was awake and calm and when the child was 4 sleeping quietly (sleep not associated with any spontaneous movement, including eye 5 movements or vocalizations) (Table 7-12). The children were assessed for one year in order to 6 determine the repeatability of the recordings, to compare respiratory rate counts obtained by 7 stethoscope and by observation, and to construct reference percentile curves by age in a large 8 number of subjects. 9 The authors plotted the differences between respiratory rate counts determined by 10 stethoscope at 30- to 60-minute intervals against their mean count in waking and sleeping 11 subjects. The standard deviation of the differences between the two counts was 2.5 and 1.7 12 breaths/minute, respectively, for waking and sleep ing children. This standard deviation yielded 13 95% repeatability coefficients of 4.9 breaths when the infants and children were awake and 3.3 14 breaths when they were asleep. 15 In both waking and sleeping states, the respiratory rate counts determined by stethoscope 16 were found to be higher than those obtained by observation. The mean difference was 2.6 and 17 1.8 breaths per minute, respectively, in waking and sleeping states. The mean respiratory rate 18 counts were significantly higher in infants and children at all ages when awake and calm than 19 when asleep. A decrease in respiratory rate with increasing age was seen in waking and sleeping 20 infants and children. A scatter diagram of respiratory rate counts by age in waking and sleeping 21 subjects showed that the pattern of respiratory rate decline with age was similar in both states, 22 but it was much faster in the first few months of life. The authors constructed centile curves by 23 first log-transforming the data and then applying a second degree polynormal curve, which 24 allowed excellent fitting to observed data. Figures 7-1 and 7-2 show smoothed percentiles by 25 age in waking and sleeping subjects, respectively. 26 The authors suggested that the differences between the reported respiratory rates in 27 healthy infants and children might be due to various factors, including the number of infants 28 studied, the period of time of counting, the method of counting, and the state of the infant. The 29 variability of respiratory rate among subjects was higher in the first few months of life, which 30 may be attributable to biological events that occur during these months, such as maturation of the 31

### 7-9 neurologic control of breathing and changes in lung and chest wall compliance and lung 1
volumes. 2 An advantage of this study is that it provides distribution data for respiratory rate for 3 children from infancy (less than 2 months) to 36 months old. These data are not U.S. data; 4 however, U.S. distributions were not available. 5
6 7.2.6 Lordo et al., 2006 7 Lordo et al. (2006), under direction from EPA’s National Center for Environmental 8 Assessment (NCEA), conducted a study to ascertain ventilation rates for children and adults. 9 Specifically, they sought to improve upon th e methodology used by Layton (1993) and other 10 studies that relied upon the ventilatory equivalent (VQ) and a linear relationship between oxygen 11 consumption and fitness rate. The authors used a revised approach, developed by EPA’s 12 National Exposure Research Laboratory (NERL), in which an individual’s ventilation rate is 13 derived from his or her oxygen consumption rate. Lo rdo et al. apply this revised approach using 14 weight data from the 1999-2002 NHANES and metabo lic equivalents (METS) data from EPA’s 15 Consolidated Human Activity Database (CHAD). 16 NHANES provided age, gender, and body we ight data for 19,022 individuals from 17 throughout the United States. From these data, basal metabolic rate (BMR) was estimated using 18 an age-specific linear equation used in Appendix 5A the Exposure Factors Handbook (EPA, 19 1997), and in several other studies and reference works. 20 The CHAD database is a compilation of several databases of human activity patterns. 21 Lordo et al. used one of these studies, the National Human Activity Pattern Survey (NHAPS), as 22 its source for METS values because it was more representative of the entire United States 23 population than the other studies in the database. The NHAPS data set included activity data for 24 9,196 individuals, each of which provided 24 hours of activity pattern data using a diary-based 25 questionnaire. While NHAPS was identified as the best available data source for activity 26 patterns, there were some shortcomings in the quality of the data. Study respondents did not 27 provide body weights; instead, body weights are simu lated using statistical sampling. Also, the 28
NHAPS data extracted from CHAD could not be corrected to account for non-random sampling 29 of study participants and survey days. 30

### 7-10 NHANES and NHAPS data were grouped into age categories using the standardized age 1 categories presented elsewhere in this Handbook, with the exception that children under the age 2 of one year were placed into a single category to preserve an adequate sample size within the 3 category. For each NHANES participant, a “simulated” 24-hour activity pattern was generated 4 by randomly sampling activity patterns from the set of NHAPS participants with the same 5 gender and age category as the NHANES participant. Twenty such patterns were selected at 6 random for each NHANES participant, resulting in 480 hours of simulated activity data for each 7 NHANES participant. The data were then scaled down to a 24-hour time frame to yield an 8 average 24-hour activity pattern for each of the 19,022 NHANES individuals. 9 Each activity was assigned a METS value based on statistical sampling of the statistical 10 distribution assigned by CHAD to each activity code. For most codes, these distributions were 11 not age-dependent, but age was a factor for some activities for which intensity level varies 12 strongly with age. Using statistical software , equations for METS based on normal, lognormal, 13 exponential, triangular, and uniform distributions were generated as needed for the various 14 activity codes. The METS values were then translated into energy expenditure ( EE ) by 15 multiplying the METS by the basal metabolic rate (BMR), which was calculated as a linear 16 function of body weight. The oxygen consumption rate VO 2 

### was calculated by multiplying EE by 17
H , the volume of oxygen consumed per unit of energy. VO 2 

### was calculated both as volume per 18 time and as volume per time per unit body weight. 19 The ventilation rate for each activity within the 24-hour simulated activity pattern for 20
each individual was estimated as a function of VO 2 

### , body weight, age, and gender. Following 21 this, average ventilation rate was calculated for each individual for the entire 24-hour period, as 22 well as for four separate classes of activities based on METS value (sedentary/passive (METS 23 less than or equal to 1.5), light intensity (METS greater than 1.5 and less than or equal to 3.0), 24 moderate intensity (METS greater than 3.0 and less than or equal to 6.0), and high intensity 25 (METS greater than 6.0)). Data for individuals were then used to generate summary tables based 26 on gender and age categories. 27 Data from this study are presented in Ta bles 7-13 through 7-19. Tables 7-13 and 7-14 28 present, for male and female subjects respectively, summary statistics for daily average 29 ventilation rate by age category on a volumetric (L/min) and weight adjusted (L/min-kg) basis. 30 Tables 7-15 and 7-16 present, for male and female subjects respectively, mean ventilation rates 31

### 7-11 by age category on a volumetric (L/min) and weight adjusted (L/min-kg) basis for the five 1 different activity level ranges described above. They also present the daily ventilation rates 2 (L/day and L/day-kg) for each activity level and age group and the mean number of hours spent 3 engaged in each of these activities by subjects in each age group. 4 Tables 7-17 and 7-18 present the same data as Tables 7-13 and 7-14, respectively, but in 5
units of m 3 

### /day and m 3 

### /day-kg rather than L/min and L/min-kg. Table 7-19 presents the number 6 of hours spent at each activity level by males and females; the data are similar to the activity data 7 presented in Tables 7-15 and 7-16 but offer percentile data in addition to the mean. 8
9
7.3 RECOMMENDATIONS 10 The recommended inhalation rates for children are based on the EPA-sponsored research 11 of Lordo et al. (2006), which is the most recent and geographically broad of the studies described 12 in this chapter. The study represents an improvement upon studies previously used for 13 recommended inhalation rates in this Handbook in that it uses a large data set that is 14 representative of the United States as a whole and considers the correlation between body weight 15 and inhalation rate. The confidence level for the studies considered in this chapter are presented 16
in Table 7-20. 17 Table 7-21 summarizes the short-and long-term inhalation rates for the standard age 18 categories used in this Handbook. 19

### 7-12 

## 7.4 REFERENCES FOR CHAPTER 7 1 2 Adams, W.C. (1993) Measurement of breathing rate a nd volume in routinely performed daily activities, Final 

### 3 Report. California Air Resources Board (CARB) Contract No. A033-205. June 1993. 185 pgs. 

### 4 5 Basiotis, P.P.; Thomas, R.G.; Kelsay, J.L.; Mertz, W. (1989) Sources of variation in energy intake by men and 

### 6 women as determined from one year’s daily di etary records. Am. J. Clin. Nutr. 50:448-453. 

### 7 8 Layton, D.W. (1993) Metabolically consistent breathing ra tes for use in dose assessments. Health Physics 64(1):23- 

### 9 36. 

### 10 11 Linn, W.S.; Shamoo, D.A.; Hackney, J.D. (1992) Document ation of activity patterns in "high-risk" groups exposed 

### 12 to ozone in the Los Angeles area. In: Proceedi ngs of the Second EPA/AWMA Conference on Tropospheric 

### 13 Ozone, Atlanta, Nov. 1991. pp. 701-712. Air a nd Waste Management Assoc., Pittsburgh, PA. 

### 14 15 Lordo, B.; Sanford, J.; Mohnson, M. (2006) Revision of the Metabolically-Derived Ventilation Rates Within the 

### 16 Exposure Factors Handbook. Battelle Institute, Columbus , OH. Prepared for USEPA/ORD, Contract No. 

### 17 EP-C-04-027. 

### 18 19 Rusconi, F.; Castagneto, M.; Garliardi, L. ; Leo, G.; Pellegatta, A.; Porta, N.; R azon, S.; Braga, M. (1994) Reference 

### 20 values for respiratory rate in the first 3 years of life. Pediatrics 94(3):350-5. September 1994. 

### 21 22 Spier, C.E.; Little, D.E.; Trim, S.C. ; Johnson, T.R.; Linn, W.S.; Hackne y, J.D. (1992) Activity patterns in 

### 23 elementary and high school students exposed to oxidant pollution. J. Exp. Anal. Environ. Epid. 2(3):277- 

### 24 293. 

### 25 26 WHO (1986) Principles for evaluating health risks from ch emicals during infancy and early childhood: the need for 

### 27 a special approach. Environmental Health Criteri a 59, World Health Organization, International 

### 28 Programme on Chemical Safety. 

### 29 30 31 32

### 7-13 Table 7-1. Calibration And Field Protocols For Self-monitoring of Activities Grouped by Subject Panels

Panel Calibration Protocol Field Protocol Panel 2 - Healthy Elementary School Students - 5 male, 12 female, age 10-12 Outdoor exercises each consisted of 20 minute rest, slow walking, jogging and fast walking Saturday, Sunday and Monday (school day) in early autumn; HR recordings and activity diary during waking hours and during sleep. Panel 3 - Healthy High School Students - 7 male, 12 female, age 13-17 Outdoor exercises each consisted of 20 minute rest, slow walking, jogging and fast walking Same as Panel 2, however, no HR recordings during sleep for most subjects. Panel 6 - Young Asthmatics - 7 male, 6 female, age 11-16 Laboratory exercise tests on bicycles and treadmills Summer monitoring for 2 successive weeks, including 2 controlled exposure studies with few or no observable respiratory effects.
Source: Linn et al., 1992

Table 7-2. Subject Panel Inhalation Rates by Mean VR , Upper Percentiles, And Self-estimated Breathing Rates

Inhalation Rates (m 3 /hr)
N a Mean VR (m 3 /hr) 99th Percentile VR Mean VR at Activity Levels (m 3 /hr) b
Panel Slow Medium Fast Healthy 2 - Elementary School Students 3 - High School Students 17 19 0.90 0.84 1.98 2.22 0.84 0.78 0.96 1.14 1.14 1.62
Asthmatics 6 - Elementary and High School Students 13 1.20 2.40 1.20 1.20 1.50

a Number of individuals in each survey panel.
b Some subjects did not report medium and/or fast activ ity. Group means were calculated from individual means (i.e., give equal weight to each individual who r ecorded any time at the indicated activity level).
Source: Linn et al., 1992

### 7-14 Table 7-3. Distribution of Predicted Intake Rates by Location And Activity Levels For Elementary And High School Students

Inhalation Rates (m 3 /hr) Percentile Rankings b

Age (yrs) Student Location Activity Level % Recorded

Time a Mean ± SD 1 st 50 th 99.9th

10-12 Elc (n d =17) Indoors slow medium

fast 49.6 23.6 2.4 0.84 ± 0.36 0.96 ± 0.36 1.02 ± 0.60 0.18 0.24 0.24 0.78 0.84 0.84 2.34 2.58 3.42
Outdoors slow medium

fast 8.9 11.2 4.3 0.96 ± 0.54 1.08 ± 0.48 1.14 ± 0.60 0.36 0.24 0.48 0.78 0.96 0.96 4.32 3.36 3.60
13-17 HS c (n d =19) Indoors slow medium

fast 70.7 10.9 1.4 0.78 ± 0.36 0.96 ± 0.42 1.26 ± 0.66 0.30 0.42 0.54 0.72 0.84 1.08 3.24 4.02 6.84 c
Outdoors slow medium

fast 8.2 7.4 1.4 0.96 ± 0.48 1.26 ± 0.78 1.44 ± 1.08 0.42 0.48 0.48 0.90 1.08 1.02 5.28 5.70 5.94

a Recorded time averaged about 23 hr per elementary school student and 33 hr. per high school student, over 72-hr. periods.
b Geometric means closely approximated 50th percentiles; ge ometric standard deviations were 1.2-1.3 for HR, 1.5-1.8 for VR.

c EL = elementary school student; HS = high school student.
d N = number of students that participated in survey.

e Highest single value.
Source: Spier et al., 1992

Table 7-4. Average Hours Spent Per Day in a Give n Location and Activity Level For Elementary and High School Students

Students

Location Activity Level Total Time Spent (hrs/day) Slow Medium Fast Elementary school, ages 10-12 years (N=17) Indoors 16.3 2.9 0.4 19.6

Outdoors 2.2 1.7 0.5 4.4 High school, ages 13-17 years (N=19) Indoors 19.5 1.5 0.2 21.2

Outdoors 1.2 1.3 0.2 2.7

Source: Spier et al., 1992 Table 7-5. Distribution Patterns of Daily Inhalation Ra tes For Elementary (EL) And High School (HS) Students Grouped by Activity Level a

### 7-15 Students Location Activity type b Mean IR c (m 3 /day) Percentile Rankings

1st 50th 99.9th Elementary school, ages 10-12 years (N=17) Indoors Light Moderate

Heavy 13.7 2.8 0.4 2.9 0.7 0.1 12.7 2.4 0.3 38.1 7.5 1.4 Outdoors Light Moderate

Heavy 2.1 1.8 0.6 0.8 0.4 0.2 1.7 1.6 0.5 9.5 5.7 1.8 High school, ages 13-17 years (N=19) Indoors Light Moderate

Heavy 15.2 1.4 0.3 5.9 0.6 0.1 14.0 1.3 0.2 63.2 6.0 1.4 Outdoors Light Moderate

Heavy 1.2 1.6 0.3 0.5 0.6 0.1 1.1 1.4 0.2 6.3 7.4 1.2

a Generated using data from Tables 7-3 and 7-4
b For this report, activity type presented in Table 7-2 was redefined as light activity for slow, moderate activity for medium, and heavy activity for fast.

c Daily inhalation rate (IR) was calculated by multiplying the hours spent at each activity level (Table 7-4) by the corresponding inhalation rate (Table 7-3).

Source: Adapted from Spier et al., 1992

### 7-16 Table 7-6. Summary of Average Inhalation Rates (m 3 /hr) by Age Group And Activity Levels for Laboratory Protocols

Age Group Activity Level Resting a Sedentary b Light c Moderate d Heavy e Young Children 

### (3-5.9 years) Average inhalation rate (m 3 /hr)
(N=12, gender not specified) 0.37 0.40 0.65 DNP f DNP f

Children 

### (6-12.9 years) Average inhalation rate (m 3 /hr)
(N=40, 20 male and 20 female) 0.45 0.47 0.95 1.74 2.23

a Resting defined as lying (see Appendix Table 7A-1 for original data).
b Sedentary defined as sitting and standing (s ee Appendix Table 7A-1 for original data).

c Light defined as walking at speed level 1.5 - 3. 0 mph (see Appendix Table 7A-1 for original data).
d Moderate defined as fast walking (3.3 - 4.0 mph) a nd slow running (3.5 - 4.0 mph) (see Appendix Table 7A-1 for original data).

e Heavy defined as fast running (4.5 - 6.0 mph) (see Appendix Table 7A-1 for original data).
f DNP. Group did not perform this protocol or N was too small for appropriate mean comparisons. All young children did not run.
Source: Adapted from Adams, 1993

### 7-17 Table 7-7. Summary of Average Inhalation Rates (m 3 /hr) by Age Group And Activity Levels in Field Protocols

Age Group Moderate Activity a
Young Children 

### (3-5.9 years) Average inhalation rate (m 3 /hr)
(N=12, gender not specified) 0.68

Children 

### (6-12.9 years) Average inhalation rate (m 3 /hr)
(N=40, 20 male and 20 female) 1.07

a Moderate activity was defined as mowing (males); w ood working (males); yard work (males); and play (children) (see Appendix Table 7A-2 for original data).
Source: Adams, 1993.

### 7-18 Table 7-8. Comparisons of Estimated Basal Metabolic Rates (BMR) With Average Food-energy Intakes (EFD) For Individuals Sampled in The 1977-78 NFCS

Cohort/Age

(years) Body Weight kg BMR a Energy Intake (EFD) Ratio EFD/BMR MJ d -1 kcal d -1 MJ d -1 kcal d -1

Children
< 1 7.6 1.74 416 3.32 793 1.90
1 to 2 13 3.08 734 5.07 1209 1.65
3 to 5 18 3.69 881 6.14 1466 1.66
6 to 8 26 4.41 1053 7.43 1774 1.68
Males
9 to 11 36 5.42 1293 8.55 2040 1.58
12 to 14 50 6.45 1540 9.54 2276 1.48
15 to 18 66 7.64 1823 10.8 2568 1.41
Females
9 to 11 36 4.91 1173 7.75 1849 1.58
12 to 14 49 5.64 1347 7.72 1842 1.37
15 to 18 56 6.03 1440 7.32 1748 1.21

a Calculated from the appropriate age and gender-bas ed BMR equations given in Appendix Table 7A-3. MJ d -1 - mega joules/day kcal d -1 - kilo calories/day EFD= Food energy intake (Kcal/day) or (MJ/day)
Source: Layton, 1993

### 7-19 Table 7-9. Daily Inhalation Rates Calculated From Food-energy Intakes

Cohort/Age

(years) L Daily Inhalation Rate a (m 3 /day) Sleep (hours) MET Value Inhalation Rates

A b F c Inactive d (m 3 /day) Active e (m 3 /day) Children <1 1 - 2 3 - 5 6 - 8 1 2 3 3 4.5 6.8 8.3 10 11 11 10 10 1.9 1.6 1.7 1.7 2.7 2.2 2.2 2.2 2.35 4.16 4.98 5.95 6.35 9.15 10.96 13.09 Males 9 - 11 12 - 14 15 - 18 3 3 4 14 15 17 9 9 8 1.9 1.8 1.7 2.5 2.2 2.1 7.32 8.71 10.31 18.3 19.16 21.65

Females 9 - 11 12 - 14 15 - 18 3 3 4 13 12 12 9 9 8 1.9 1.6 1.5 2.5 2.0 1.7 6.63 7.61 8.14 16.58 15.22 13.84

a Daily inhalation rate was calculated by multiplying the EFD values (see Table 7-8) by H × VQ for subjects under 9 years of age and by 1.2 × H × VQ (for subjects 9 years of age and older (see text for explanation), where EFD = Food energy intake (Kcal/day) or (MJ/day), H = Oxygen uptake = 0.05 LO 2 /KJ or 0.21 LO 2 /Kcal, and VQ = Ventilation equivalent = 27 = geometric mean of VQs (unitless).
b For individuals 9 years of age and older, A was cal culated by multiplying the ratio for EFD/BMR (unitless) (Table 7-8) by the factor 1.2 (see text for explanation).

c F = (24 × A - S)/(24 - S) (unitless), ratio of the ra te of energy expenditure during active hours to the estimated BMR (unitless), where S = Number of hours spent sleeping each day.
d Inhalation rate for inactive periods was calculated as BMR × H × VQ, and for active periods by multiplying the inactive inhalation rate by F (see footnote c); BMR values are from Table 7-8, where BMR = basal metabolic rate (MJ/day) or (kg/hr).
L = number of years for each age cohort. MET = metabolic equivalent.
Source: Layton, 1993

### 7-20 Table 7-10. Daily Inhalation Rates Obtained From Th e Ratios Of Total Energy Expenditure to Basal Metabolic Rate (BMR)

Gender/Age (yrs) Body Weight a (kg) BMR b (MJ/day) VQ A c H (m 3 O 2 /MJ) Inhalation Rate, V E (m 3 /day) d
Male 0.5 - <3 3 - <10 10 - <18 14 23 53 3.4 4.3 6.7 27 27 27 1.6 1.6 1.7 0.05 0.05 0.05 7.3 9.3 15
Female 0.5 - <3 3 - <10 10 - <18 11 23 50 2.6 4.0 5.7 27 27 27 1.6 1.6 1.5 0.05 0.05 0.05 5.6 8.6 12

a Body weight was based on the average weights for age/gender cohorts in the U.S. population.
b The BMRs (basal metabolic rate) are calculated us ing the respective body weights and BMR equations (see Appendix Table 7A-3).

c The values of the BMR multiplier (EFD/BMR) for thos e 18 years and older were derived from the Basiotis et al. (1989) study: Male = 1.59, Female = 1.38. For males and females under 10 years old, the mean BMR multiplier used was 1.6. For males and females aged 10 to < 18 years, the mean values for A given in Table 7-9 for 12-14 years and 15-18 years, age brackets for males and females were used: male = 1.7 and female = 1.5.
d Inhalation rate = BMR x A x H x VQ; VQ = ventilation equivalent and H = oxygen uptake.
Source: Layton, 1993

### 7-21 Table 7-11. Inhalation Rates For Short-term Exposures

Gender/Age (yrs) Weight (kg) a BMR b (MJ/day) Activity Type Rest Sedentary Light Moderate Heavy MET (BMR Multiplier) 1 1.2 2 c 4 d 10 e Inhalation Rate (m 3 /hr) f,g
Male 0.5 - <3 3 - <10 10 - <18 Female 0.5 - <3 3 - <10 10 - <18 14 23 53

11 23 50 3.40 4.30 6.70

2.60 4.00 5.70 0.19 0.24 0.38

0.14 0.23 0.32 0.23 0.29 0.45

0.17 0.27 0.38 0.38 0.49 0.78

0.29 0.45 0.66 0.78 0.96 1.50

0.60 0.90 1.26 1.92 2.40 3.78

1.44 2.28 3.18

a Body weights were based on average weights fo r age/gender cohorts of the U.S. population
b The BMRs for the age/gender cohorts were calcula ted using the respective body weights and the BMR equations (Appendix Table 7A-3).

c Range = 1.5 - 2.5.
d Range = 3 - 5.

e Range = >5 - 20.
f The inhalation rate was calculated as IR = BMR (MJ/ day) × H (0.05 L/KJ) × MET × VQ (27) × (d/24 hrs)

g Original data were presented in L/min. Conversion to m 3 /hr was obtained as follows: 60 min h r m 1000L L min 1 × ×

Source: Layton, 1993

### 7-22 Table 7-12. Mean, Median, and SD of Respiratory Ra te According to Waking or Sleeping in 618 Infants and Children Grouped in Classes of Age

Age (months) N Respiratory Rate (breaths/min) Waking Sleeping

Mean ± SD Median Mean ± SD Median

<2 104 48.0 ± 9.1 47 39.8 ± 8.7 39

2 to <6 106 44.1 ± 9.9 42 33.4 ± 7.0 32

6 to <12 126 39.1 ± 8.5 38 29.6 ± 7.0 28

12 to <18 77 34.5 ± 5.8 34 27.2 ± 5.6 26

18 to <24 65 32.0 ± 4.8 32 25.3 ± 4.6 24

24 to <30 79 30.0 ± 6.2 30 23.1 ± 4.6 23

30 to 36 61 27.1 ± 4.1 28 21.5 ± 3.7 21

Source: Rusconi et al., 1994

### 7-23 Figure 7-1. 5th, 10th, 25th, 50th, 75th, 90th, and 95th Smoothed Centiles by Age in Awake Subjects (RR = respiratory rate). Source: Rusconi et al., 1994

Figure 7-2. 5th, 10th, 25th, 50th, 75th, 90th, and 95th Smoothed Centiles by Age in Asleep Subjects (RR = respiratory rate). Source: Rusconi et al., 19947-24Table 7-13. Descriptive Statistics for DailyAverage Ventilation Rate (L/min) in Males, by Age CategoryAge Category NDaily Average Ventilation Rate, Unadjusted for Body Weight( ; L/min)&VEDaily Average Ventilation Rate, Adjusted for Body Weight(/BW: L/min-kg)&VEMeanPercentiles Maximum MeanPercentiles Maxi-mum5th10th25th50th75th90th95th5th10th25th50th75th90th95thBirth to <1 year 419 6.08 3.32 3.96 4.97 6.04 7.24 8.28 8.81 11.84 0.759 0.634 0.655 0.696 0.754 0.808 0.872 0.898 1.0251 year 308 9.37 6.76 7.23 8.09 9.11 10.43 11.82 12.4316.83 0.823 0.669 0.706 0.7560.813 0.876 0.949 1.027 1.2012 years 261 9.19 6.56 7.09 7.94 9.16 10.07 11.30 12.3019.56 0.658 0.542 0.567 0.6060.655 0.704 0.757 0.782 0.9443 to <6 years 540 8.78 7.24 7.55 7.91 8.74 9.47 10.1610.70 13.56 0.488 0.363 0.386 0.426 0.481 0.540 0.606 0.639 0.7536 to <11 years940 9.32 7.00 7.42 8.15 9.09 10.2311.50 12.31 17.34 0.307 0.221 0.2380.261 0.302 0.346 0.381 0.403 0.55911 to <16 years1337 10.64 7.92 8.41 9.22 10.27 11.6813.57 14.73 19.82 0.198 0.144 0.1530.171 0.192 0.220 0.252 0.267 0.35116 to <21 years1241 11.95 8.75 9.31 10.06 11.55 13.3115.23 16.23 27.23 0.159 0.116 0.1260.140 0.158 0.176 0.194 0.206 0.274Individual daily averages are weighted by their 4-year sampling weights as assigned within NHANES 1999-2002 when calculating the statistics in this table. Ventilation rate wasestimated using a multiple linear regression model.Source: Lordo et al., 20067-25Table 7-14. Descriptive Statistics for DailyAverage Ventilation Rate (L/min) in Females, by Age CategoryAge Category NDaily Average Ventilation Rate, Unadjusted for Body Weight( ; L/min)&VEDaily Average Ventilation Rate, Adjusted for Body Weight(/BW: L/min-kg)&VEMeanPercentiles Maximum MeanPercentiles Maxi-mum5th10th25th50th75th90th95th5th10th25th50th75th90th95thBirth to <1 year 415 5.92 3.36 3.81 4.75 5.84 6.79 8.09 8.79 18.23 0.793 0.634 0.673 0.720 0.782 0.863 0.922 0.961 1.1121 year 245 9.24 6.31 7.03 7.81 9.05 10.17 12.12 12.9317.20 0.831 0.677 0.703 0.7650.818 0.901 0.976 1.017 1.2002 years 255 8.85 6.19 6.99 7.90 8.75 9.69 10.82 11.3615.98 0.663 0.569 0.583 0.6180.664 0.703 0.740 0.767 0.8573 to <6 years 543 8.45 6.86 7.21 7.78 8.35 9.04 9.7410.37 13.71 0.480 0.335 0.372 0.414 0.475 0.533 0.614 0.636 0.7756 to <11 years 894 8.62 6.94 7.19 7.65 8.30 9.32 10.5111.35 14.46 0.297 0.194 0.214 0.248 0.296 0.339 0.381 0.404 0.51911 to <16 years 1451 9.33 7.27 7.72 8.36 9.08 10.10 11.2912.09 18.46 0.174 0.131 0.138 0.153 0.170 0.194 0.217 0.236 0.32716 to <21 years 1182 9.44 6.85 7.37 8.18 9.17 10.43 11.8912.70 20.91 0.148 0.110 0.117 0.132 0.144 0.163 0.186 0.197 0.248Individual daily averages are weighted by their 4-year sampling weights as assigned within NHANES 1999-2002 when calculating the statistics in this table. Ventilation rate wasestimated using a multiple linear regression model.Source: Lordo et al., 2006

### 7-26 Table 7-15. Average Time Spent Per Day Performing Activ ities Within Specified Intensity Categories, and Average Ventilation Rates Associated With These Activity Categories, for Males According to Age Category

Age Category # NHANES Participants Reporting Activity Average Duration (hr/day) Spent at Activity Ventilation Rate During This Activity 1 Daily Ventilation Rate Associated With This Activity 2 Unadjusted for Body Weight (L/min) Adjusted for Body Weight

(L/min-kg) Unadjusted for Body Weight (L/day) Adjusted for Body Weight

(L/day-kg) Sleep or nap (Activity ID = 14500) Birth to <1 year 419 13.5 3.08 0.385 2,499 311.8 1 year 308 12.6 4.50 0.395 3,405 298.9 2 years 261 12.1 4.61 0.330 3,334 239.1 3 to <6 years 540 11.2 4.36 0.243 2,928 162.9 6 to <11 years 940 10.2 4.61 0.151 2,814 92.5 11 to <16 years 1,337 9.4 5.26 0.098 2,958 54.9 16 to <21 years 1,241 8.7 5.31 0.071 2,769 36.9 21 to <31 years 701 8.4 4.73 0.058 2,368 29.0 31 to <41 years 728 8.1 5.16 0.061 2,496 29.4 41 to <51 years 753 7.9 5.65 0.065 2,676 30.9 51 to <61 years 627 8.0 5.78 0.066 2,757 31.7 61 to <71 years 678 8.3 5.98 0.069 2,979 34.5 71 to <81 years 496 8.5 6.07 0.075 3,098 38.1 81 years and older 255 9.2 5.97 0.080 3,309 44.3 Sedentary & Passive Activities (METS 

### # 1.5 -- Includes Sleep or Nap) Birth to <1 year 419 15.0 3.18 0.397 2,858 355.9 1 year 308 14.3 4.62 0.406 3,958 347.5 2 years 261 14.6 4.79 0.343 4,206 301.7 3 to <6 years 540 14.1 4.58 0.255 3,886 216.0 6 to <11 years 940 13.5 4.87 0.160 3,949 130.2 11 to <16 years 1,337 13.8 5.64 0.105 4,692 87.1 16 to <21 years 1,241 13.2 5.76 0.077 4,575 61.1 21 to <31 years 701 12.4 5.11 0.062 3,807 46.6 31 to <41 years 728 12.3 5.57 0.066 4,117 48.6 41 to <51 years 753 12.3 6.11 0.071 4,522 52.2 51 to <61 years 627 13.1 6.27 0.072 4,918 56.5 61 to <71 years 678 14.5 6.54 0.076 5,693 66.1 71 to <81 years 496 15.9 6.65 0.082 6,345 78.1 81 years and older 255 16.6 6.44 0.086 6,411 85.9Age Category # NHANES Participants Reporting Activity Average Duration (hr/day) Spent at Activity Ventilation Rate During This Activity 1 Daily Ventilation Rate Associated With This Activity 2 Unadjusted for Body Weight (L/min) Adjusted for Body Weight

(L/min-kg) Unadjusted for Body Weight (L/day) Adjusted for Body Weight

(L/day-kg)



### 7-27 Light Intensity Activities (1.5 < METS 

### # 3.0) Birth to <1 year 419 5.3 7.94 0.988 2,603 322.7 1 year 308 5.5 11.56 1.019 3,959 350.7 2 years 261 5.5 11.67 0.837 3,917 281.9 3 to <6 years 540 6.6 11.36 0.633 4,561 255.2 6 to <11 years 940 7.6 11.64 0.384 5,345 177.5 11 to <16 years 1,337 7.5 13.22 0.246 5,943 110.9 16 to <21 years 1,241 7.1 13.41 0.179 5,745 76.9 21 to <31 years 701 6.1 12.97 0.158 4,821 58.5 31 to <41 years 728 5.7 13.64 0.161 4,714 55.5 41 to <51 years 753 6.1 14.38 0.166 5,271 60.8 51 to <61 years 627 5.6 14.56 0.167 5,005 57.0 61 to <71 years 678 5.5 14.12 0.164 4,669 54.0 71 to <81 years 496 5.0 13.87 0.171 4,131 50.8 81 years and older 255 4.9 13.76 0.185 4,014 53.9 Moderate Intensity Activities (3.0 < METS 

### # 6.0) Birth to <1 year 419 3.7 14.49 1.804 3,157 396.5 1 year 308 4.0 21.35 1.878 5,141 451.0 2 years 261 3.8 21.54 1.546 4,958 353.4 3 to <6 years 540 3.2 21.03 1.173 3,890 214.5 6 to <11 years 940 2.7 22.28 0.736 3,567 115.1 11 to <16 years 1,337 2.3 26.40 0.491 3,733 68.8 16 to <21 years 1,241 3.3 29.02 0.387 5,904 78.3 21 to <31 years 701 5.2 29.19 0.357 9,369 115.2 31 to <41 years 728 5.7 30.30 0.357 10,560 124.1 41 to <51 years 753 5.4 31.58 0.366 10,438 121.3 51 to <61 years 627 5.0 32.71 0.376 9,953 115.1 61 to <71 years 678 3.7 29.76 0.344 6,705 77.4 71 to <81 years 496 2.9 29.29 0.360 5,058 62.0 81 years and older 255 2.3 28.53 0.383 4,036 54.1Age Category # NHANES Participants Reporting Activity Average Duration (hr/day) Spent at Activity Ventilation Rate During This Activity 1 Daily Ventilation Rate Associated With This Activity 2 Unadjusted for Body Weight (L/min) Adjusted for Body Weight

(L/min-kg) Unadjusted for Body Weight (L/day) Adjusted for Body Weight

(L/day-kg)



### 7-28 High Intensity (METS > 6.0) Birth to <1 year 183 0.2 27.47 3.477 325 41.2 1 year 164 0.3 40.25 3.523 799 68.3 2 years 162 0.1 40.45 2.889 242 17.4 3 to <6 years 263 0.3 39.04 2.167 639 34.3 6 to <11 years 637 0.3 43.62 1.410 851 28.2 11 to <16 years 1,111 0.4 50.82 0.950 1,154 21.9 16 to <21 years 968 0.4 53.17 0.711 1,275 16.9 21 to <31 years 546 0.3 53.91 0.660 1,041 12.8 31 to <41 years 567 0.4 54.27 0.644 1,183 14.1 41 to <51 years 487 0.3 57.31 0.655 1,124 12.7 51 to <61 years 452 0.4 58.42 0.675 1,441 16.5 61 to <71 years 490 0.4 54.13 0.624 1,158 13.3 71 to <81 years 343 0.4 52.46 0.646 1,181 14.6 81 years and older 168 0.3 53.31 0.716 1,052 13.9

1 An individual’s ventilation rate for the given activity category equals the weighted average of the individual’s activity-spec ific ventilation rates for activities falling within the category, estim ated using a multiple linear regression model, with weights corresponding to the number of minutes spen t performing the activity. Numbers in these two columns represent averages, calculated across individuals in the specified age category, of th ese weighted averages. These ar e weighted averages, with the weights corresponding to the 4-year samp ling weights assigned within NHANES 1999-2002.

2 An individual’s daily average ventilation rate equals the produc t of the individual’s weighted average ventilation rate for th e given activity category (L/min), estimated using a multiple linear regression model, and the number of minutes per day that the individual performs an activity within the category. Number s in these two columns represent weighted averages across individuals in the specified age category, with the weight s corresponding to the 4-year sampling weights assigned within NHANES 1999-2002.
Source: Lordo et al., 2006

### 7-29 Table 7-16. Average Time Spent Per Day Performing Activ ities Within Specified Intensity Categories, and Average Ventilation Rates Associated With These Activity Categories, for Females According to Age Category

Age Category # NHANES Participants Reporting Activity Average Duration (hr/day) Spent at Activity Ventilation Rate During This Activity 1 Daily Ventilation Rate Associated With This Activity 2 Unadjusted for Body Weight (L/min) Adjusted for Body Weight

(L/min-kg) Unadjusted for Body Weight (L/day) Adjusted for Body Weight

(L/day-kg) Sleep or nap (Activity ID = 14500) Birth to <1 year 415 13.0 2.92 0.391 2,275 304.9 1 year 245 12.6 4.59 0.414 3,466 313.0 2 years 255 12.1 4.56 0.342 3,307 248.4 3 to <6 years 543 11.1 4.18 0.238 2,788 158.9 6 to <11 years 894 10.3 4.36 0.151 2,686 92.7 11 to <16 years 1,451 9.6 4.81 0.090 2,766 51.6 16 to <21 years 1,182 9.1 4.40 0.069 2,398 37.7 21 to <31 years 1,023 8.6 3.89 0.055 2,009 28.6 31 to <41 years 869 8.3 4.00 0.056 1,996 27.8 41 to <51 years 763 8.3 4.40 0.060 2,197 29.9 51 to <61 years 622 8.1 4.56 0.061 2,222 29.8 61 to <71 years 700 8.4 4.47 0.061 2,255 30.5 71 to <81 years 470 8.6 4.52 0.066 2,325 33.9 81 years and older 306 9.1 4.49 0.072 2,456 39.1 Sedentary & Passive Activities (METS 

### # 1.5 -- Includes Sleep or Nap) Birth to <1 year 415 14.1 3.00 0.402 2,538 339.4 1 year 245 14.3 4.71 0.425 4,046 365.9 2 years 255 14.9 4.73 0.355 4,215 316.4 3 to <6 years 543 14.3 4.40 0.251 3,773 214.8 6 to <11 years 894 14.0 4.64 0.160 3,898 134.3 11 to <16 years 1,451 14.2 5.21 0.097 4,442 83.1 16 to <21 years 1,182 13.6 4.76 0.075 3,876 61.0 21 to <31 years 1,023 12.6 4.19 0.060 3,164 45.0 31 to <41 years 869 12.3 4.33 0.060 3,197 44.7 41 to <51 years 763 12.2 4.75 0.065 3,489 47.5 51 to <61 years 622 12.7 4.96 0.067 3,771 50.7 61 to <71 years 700 14.3 4.89 0.066 4,183 56.6 71 to <81 years 470 15.4 4.95 0.072 4,569 66.6 81 years and older 306 16.5 4.89 0.078 4,841 77.3Table 7-16. Average Time Spent Per Day Performing Activ ities Within Specified Intensity Categories, and Average Ventilation Rates Associated With These Activity Categories, for Females According to Age Category (continued)

Age Category # NHANES Participants Reporting Activity Average Duration (hr/day) Spent at Activity Ventilation Rate During This Activity 1 Daily Ventilation Rate Associated With This Activity 2 Unadjusted for Body Weight (L/min) Adjusted for Body Weight

(L/min-kg) Unadjusted for Body Weight (L/day) Adjusted for Body Weight

(L/day-kg)



### 7-30 Light Intensity Activities (1.5 < METS 

### # 3.0) Birth to <1 year 415 6.0 7.32 0.978 2,727 362.7 1 year 245 5.6 11.62 1.050 4,019 366.8 2 years 255 5.8 11.99 0.897 4,255 318.5 3 to <6 years 543 6.3 10.92 0.619 4,148 235.6 6 to <11 years 894 7.3 11.07 0.382 4,845 167.0 11 to <16 years 1,451 7.6 12.02 0.225 5,454 101.9 16 to <21 years 1,182 7.0 11.08 0.174 4,660 73.2 21 to <31 years 1,023 6.4 10.55 0.149 4,075 57.7 31 to <41 years 869 6.5 11.07 0.154 4,338 60.5 41 to <51 years 763 6.6 11.78 0.161 4,656 63.8 51 to <61 years 622 6.5 12.02 0.161 4,714 63.2 61 to <71 years 700 6.2 10.82 0.147 4,046 55.1 71 to <81 years 470 6.0 10.83 0.158 3,873 56.6 81 years and older 306 5.3 10.40 0.167 3,308 52.9 Moderate Intensity Activities (3.0 < METS 

### # 6.0) Birth to <1 year 415 3.9 13.98 1.866 3,222 434.0 1 year 245 4.0 20.98 1.896 5,118 452.5 2 years 255 3.3 21.34 1.600 4,076 306.0 3 to <6 years 543 3.4 20.01 1.135 3,986 226.0 6 to <11 years 894 2.6 21.00 0.723 3,220 111.0 11 to <16 years 1,451 2.0 23.55 0.441 2,852 53.3 16 to <21 years 1,182 3.3 23.22 0.365 4,586 72.0 21 to <31 years 1,023 4.8 22.93 0.325 6,769 95.9 31 to <41 years 869 5.0 22.70 0.316 6,927 96.4 41 to <51 years 763 5.0 24.49 0.333 7,559 102.1 51 to <61 years 622 4.6 25.24 0.339 7,026 94.6 61 to <71 years 700 3.3 21.42 0.292 4,255 58.0 71 to <81 years 470 2.5 21.09 0.308 3,140 45.8 81 years and older 306 2.1 20.87 0.335 2,580 41.4Table 7-16. Average Time Spent Per Day Performing Activ ities Within Specified Intensity Categories, and Average Ventilation Rates Associated With These Activity Categories, for Females According to Age Category (continued)

Age Category # NHANES Participants Reporting Activity Average Duration (hr/day) Spent at Activity Ventilation Rate During This Activity 1 Daily Ventilation Rate Associated With This Activity 2 Unadjusted for Body Weight (L/min) Adjusted for Body Weight

(L/min-kg) Unadjusted for Body Weight (L/day) Adjusted for Body Weight

(L/day-kg)



### 7-31 High Intensity (METS > 6.0) Birth to <1 year 79 0.2 24.19 3.263 244 32.3 1 year 55 0.2 36.48 3.376 471 44.3 2 years 130 0.2 37.58 2.800 355 25.6 3 to <6 years 347 0.2 34.53 1.979 407 23.4 6 to <11 years 707 0.2 39.39 1.331 568 18.7 11 to <16 years 1,170 0.3 46.56 0.879 840 15.8 16 to <21 years 887 0.2 44.09 0.696 621 9.8 21 to <31 years 796 0.3 45.68 0.650 725 10.2 31 to <41 years 687 0.2 44.44 0.613 646 8.9 41 to <51 years 515 0.3 46.98 0.653 725 10.1 51 to <61 years 424 0.3 47.35 0.634 965 13.0 61 to <71 years 465 0.3 40.02 0.544 777 10.5 71 to <81 years 304 0.3 40.64 0.594 718 10.5 81 years and older 188 0.3 41.88 0.666 654 10.7

1 An individual’s ventilation rate for the given activity category equals the weighted average of the individual’s activity-spec ific ventilation rates for activities falling within the category, estim ated using a multiple linear regression model, with weights corresponding to the number of minutes spen t performing the activity. Numbers in these two columns represent averages, calculated across individuals in the specified age category, of th ese weighted averages. These ar e weighted averages, with the weights corresponding to the 4-year samp ling weights assigned within NHANES 1999-2002.

2 An individual’s daily average ventilation rate equals the produc t of the individual’s weighted average ventilation rate for th e given activity category (L/min), estimated using a multiple linear regression model, and the number of minutes per day that t he individual performs an activity within the category. Number s in these two columns represent weighted averages across individuals in the specified age category, with the weight s corresponding to the 4-year sampling weights assigned within NHANES 1999-2002.

Source: Lordo et al., 20067-32Table 7-17. Descriptive Statistics for Daily Average Ventilation Rate (m3/day) in Males, by Age CategoryAge Category NDaily Average Ventilation Rate, Unadjusted for Body Weight( ; m3/day)&VEDaily Average Ventilation Rate, Adjusted for Body Weight(/BW: m3/day-kg)&VEMeanPercentiles Maximum MeanPercentiles Maxi-mum5th10th25th50th75th90th95th5th10th25th50th75th90th95thBirth to <1 year 419 8.76 4.77 5.70 7.16 8.70 10.43 11.93 12.69 17.05 1.093 0.913 0.943 1.002 1.085 1.163 1.256 1.293 1.4761 year 308 13.49 9.73 10.41 11.65 13.1115.02 17.03 17.89 24.24 1.186 0.964 1.017 1.088 1.171 1.261 1.367 1.479 1.7302 years 261 13.23 9.45 10.20 11.43 13.19 14.49 16.27 17.71 28.17 0.948 0.781 0.816 0.873 0.943 1.014 1.090 1.127 1.3603 to <6 years 540 12.65 10.42 10.87 11.40 12.58 13.64 14.6315.41 19.52 0.703 0.523 0.555 0.613 0.693 0.778 0.873 0.920 1.0846 to <11 years940 13.42 10.08 10.69 11.73 13.09 14.7316.56 17.72 24.97 0.441 0.318 0.3430.376 0.434 0.499 0.549 0.581 0.80511 to <16 years1337 15.32 11.41 12.11 13.27 14.79 16.8119.54 21.21 28.54 0.285 0.208 0.2210.246 0.276 0.317 0.362 0.384 0.50516 to <21 years1241 17.22 12.60 13.41 14.48 16.63 19.1621.94 23.38 39.21 0.229 0.168 0.1810.202 0.228 0.253 0.279 0.296 0.395Individual daily averages are weighted by their 4-year sampling weights as assigned within NHANES 1999-2002 when calculating the statistics in this table. Ventilation rate wasestimated using a multiple linear regression model.Source: Lordo et al., 20067-33Table 7-18. Descriptive Statistics for Daily Average Ventilation Rate (m3/day) in Females, by Age CategoryAge Category NDaily Average Ventilation Rate, Unadjusted for Body Weight( ; m3/day)&VEDaily Average Ventilation Rate, Adjusted for Body Weight(/BW: m3/day-kg)&VEMeanPercentiles Maximum MeanPercentiles Maxi-mum5th10th25th50th75th90th95th5th10th25th50th75th90th95thBirth to <1 year 415 8.53 4.84 5.48 6.83 8.41 9.78 11.65 12.66 26.26 1.142 0.913 0.969 1.037 1.127 1.243 1.327 1.384 1.6011 year 245 13.31 9.08 10.12 11.24 13.0314.64 17.45 18.62 24.77 1.197 0.975 1.013 1.102 1.178 1.297 1.405 1.465 1.7282 years 255 12.74 8.91 10.07 11.38 12.60 13.96 15.58 16.37 23.01 0.955 0.820 0.840 0.890 0.956 1.012 1.065 1.105 1.2343 to <6 years 543 12.16 9.87 10.38 11.20 12.02 13.01 14.0314.93 19.74 0.691 0.482 0.536 0.596 0.684 0.768 0.884 0.916 1.1166 to <11 years 894 12.41 9.99 10.35 11.01 11.95 13.42 15.1316.34 20.82 0.427 0.279 0.307 0.357 0.427 0.489 0.548 0.582 0.74811 to <16 years 1451 13.44 10.47 11.1112.04 13.08 14.54 16.25 17.41 26.58 0.251 0.189 0.198 0.220 0.245 0.279 0.312 0.340 0.47116 to <21 years 1182 13.59 9.86 10.6111.78 13.20 15.02 17.12 18.29 30.11 0.214 0.158 0.169 0.190 0.208 0.235 0.268 0.284 0.357Individual daily averages are weighted by their 4-year sampling weights as assigned within NHANES 1999-2002 when calculating the statistics in this table. Ventilation rate wasestimated using a multiple linear regression model.Source: Lordo et al., 20067-34Table 7-19. Descriptive Statistics for Duration of Time (hr/day) Spent Performing Activities Within the Specified Activity Category, by Age and GenderCategoriesAge CategoryDuration (hr/day) Spent at Activity – Males Duration (hr/day) Spent at Activity – FemalesN MeanPercentiles Maximum N MeanPercentiles Maxi-mum5th10th25th50th75th90th95th5th10th25th50th75th90th95thSleep or nap (Activity ID = 14500)Birth to <1 year 419 13.51 12.63 12.78 13.19 13.53 13.88 14.2414.46 15.03 415 12.99 12.00 12.16 12.53 12.96 13.44 13.82 14.07 14.821 year 308 12.61 11.89 12.15 12.34 12.6112.89 13.13 13.29 13.79 245 12.58 11.59 11.88 12.29 12.63 12.96 13.16 13.31 14.552 years 261 12.06 11.19 11.45 11.80 12.07 12.39 12.65 12.75 13.40 255 12.09 11.4511.68 11.86 12.08 12.34 12.57 12.66 13.483 to <6 years 540 11.18 10.57 10.70 10.94 11.18 11.45 11.6311.82 12.39 543 11.13 10.45 10.70 10.92 11.12 11.38 11.58 11.75 12.236 to <11 years 940 10.18 9.65 9.75 9.93 10.19 10.39 10.5910.72 11.24 894 10.26 9.55 9.73 10.01 10.27 10.54 10.74 10.91 11.4311 to <16 years 1337 9.38 8.84 8.94 9.15 9.38 9.61 9.839.95 10.33 1451 9.57 8.82 8.97 9.27 9.55 9.87 10.17 10.31 11.5216 to <21 years 1241 8.69 7.91 8.08 8.36 8.67 9.03 9.349.50 10.44 1182 9.08 8.26 8.44 8.74 9.08 9.39 9.79 10.02 11.11Sedentary & PassiveActivities (METS#1.5 -- Includes Sleep or Nap)Birth to <1 year 419 14.95 13.82 14.03 14.49 14.88 15.44 15.9016.12 17.48 415 14.07 12.86 13.05 13.53 14.08 14.54 15.08 15.49 16.141 year 308 14.27 13.22 13.33 13.76 14.2514.74 15.08 15.38 16.45 245 14.32 13.02 13.25 13.73 14.31 14.88 15.36 15.80 16.402 years 261 14.62 13.52 13.67 14.11 14.54 15.11 15.60 15.77 17.28 255 14.86 13.8113.95 14.44 14.81 15.32 15.78 16.03 16.913 to <6 years 540 14.12 13.01 13.18 13.54 14.03 14.53 15.2615.62 17.29 543 14.27 12.88 13.15 13.56 14.23 14.82 15.43 15.85 17.966 to <11 years 940 13.51 12.19 12.45 12.86 13.30 13.85 14.82 15.94 19.21 894 13.97 12.49 12.74 13.22 13.82 14.50 15.34 16.36 18.6811 to <16 years 1337 13.85 12.39 12.65 13.06 13.61 14.30 15.41 16.76 18.79 1451 14.19 12.38 12.76 13.34 14.05 14.82 15.87 16.81 19.2716 to <21 years 1241 13.21 11.39 11.72 12.32 13.08 13.97 14.83 15.44 18.70 1182 13.58 11.80 12.17 12.79 13.52 14.29 15.08 15.67 16.96Light Intensity Activities (1.5 < METS#3.0)Birth to <1 year 419 5.30 2.97 3.25 3.71 4.52 7.29 8.088.50 9.91 415 6.00 3.49 3.70 4.26 5.01 8.43 9.31 9.77 10.531 year 308 5.52 2.68 2.89 3.37 4.31 8.23 9.04 9.73 10.90 245 5.61 2.83 2.94 3.464.39 8.28 9.03 9.39 10.572 years 261 5.48 3.06 3.26 3.85 4.58 7.58 8.83 9.049.92 255 5.78 3.20 3.54 4.295.33 7.48 8.46 8.74 9.933 to <6 years 540 6.60 3.86 4.25 5.16 6.20 8.26 9.319.70 10.74 543 6.25 3.78 4.10 4.79 5.84 7.86 8.84 9.38 10.326 to <11 years 940 7.62 5.07 5.57 6.63 7.63 8.72 9.7810.12 11.59 894 7.27 4.63 5.46 6.33 7.17 8.34 9.42 9.79 11.0611 to <16 years 1337 7.50 4.48 5.59 6.75 7.67 8.51 9.199.63 10.91 1451 7.55 4.89 5.62 6.75 7.67 8.55 9.27 9.57 10.8516 to <21 years 1241 7.13 4.37 4.97 6.00 7.02 8.29 9.4310.03 11.50 1182 6.98 4.60 5.08 5.91 6.85 7.96 9.16 9.57 12.29Age CategoryDuration (hr/day) Spent at Activity – Males Duration (hr/day) Spent at Activity – FemalesN MeanPercentiles Maximum N MeanPercentiles Maxi-mum5th10th25th50th75th90th95th5th10th25th50th75th90th95th7-35Moderate Intensity Activities (3.0 < METS#6.0)Birth to <1 year 419 3.67 0.63 0.97 1.74 4.20 5.20 5.806.21 7.52 415 3.91 0.53 0.74 1.10 4.87 5.77 6.27 6.54 7.681 year 308 4.04 0.45 0.59 1.14 5.29 6.06 6.61 6.94 7.68 245 4.02 0.52 0.73 1.085.14 6.10 7.00 7.37 8.072 years 261 3.83 0.59 0.76 1.23 4.74 5.37 5.82 6.157.40 255 3.27 0.50 0.78 1.224.01 4.88 5.35 5.57 6.933 to <6 years 540 3.15 0.55 0.75 1.30 3.80 4.52 5.115.32 6.30 543 3.35 0.70 0.89 1.61 3.88 4.71 5.29 5.65 7.586 to <11 years 940 2.66 0.65 0.92 1.65 2.68 3.57 4.364.79 5.95 894 2.57 0.65 0.95 1.82 2.66 3.41 3.95 4.32 6.1011 to <16 years 1337 2.35 0.88 1.09 1.66 2.30 3.02 3.623.89 5.90 1451 2.01 0.89 1.08 1.45 1.96 2.51 3.03 3.28 4.9616 to <21 years 1241 3.35 1.13 1.42 2.19 3.45 4.37 5.245.59 6.83 1182 3.26 1.27 1.48 2.21 3.39 4.24 4.74 5.07 6.68High Intensity (METS > 6.0)Birth to <1 year 183 0.20 0.00 0.00 0.01 0.14 0.28 0.500.59 0.96 79 0.17 0.03 0.05 0.09 0.14 0.21 0.33 0.40 0.581 year 164 0.31 0.01 0.01 0.03 0.22 0.56 0.78 0.93 1.52 55 0.22 0.03 0.05 0.090.18 0.35 0.40 0.43 0.482 years 162 0.10 0.00 0.01 0.03 0.05 0.14 0.25 0.330.48 130 0.15 0.00 0.01 0.030.08 0.16 0.48 0.65 1.013 to <6 years 263 0.27 0.02 0.03 0.04 0.13 0.33 0.751.16 1.48 347 0.19 0.01 0.02 0.05 0.10 0.22 0.46 0.73 1.436 to <11 years 637 0.32 0.01 0.01 0.03 0.13 0.38 1.101.50 3.20 707 0.24 0.02 0.03 0.06 0.12 0.26 0.67 0.98 1.7111 to <16 years 1111 0.38 0.03 0.04 0.10 0.21 0.47 1.031.34 2.35 1170 0.30 0.03 0.04 0.08 0.19 0.40 0.66 0.96 3.1616 to <21 years 968 0.40 0.03 0.04 0.14 0.27 0.53 0.991.29 2.59 887 0.24 0.01 0.03 0.08 0.18 0.34 0.51 0.60 1.61Individual measures are weighted by their 4-year samplingweights as assigned within NHANES 1999-2002 when calculating the statistics in this table. Ventilation rate wasestimated using a multiple linear regression model.Source: Lordo et al., 2006.

### 7-36 Table 7-20. Confidence in Inhalation Rate Recommendations

Considerations Rationale Rating Study Elements Peer Review The key study used in the recommendations has undergone internal peer review, but not external review yet. The primary data used in the study have been peer reviewed. Medium

Accessibility The Lordo et al. 2006 is not yet available in the peer review literature, however the primary data sets used in the study are publicly available. Medium

Reproducibility Results can be reproduced using the primary data publicly available. Medium

Focus on factor of interest Study focused on ventilation rates and factors influencing them. High

Data pertinent to U.S. Studies conducted in the U.S. High Primary data Lordo et al. 2006 is an analysis of existing primary data. Medium

Currency Recent studies were evaluated. High Adequacy of data collection period E ffort was made to collect data over time. High Validity of approach Measurements were made by indirect methods. Medium Representativeness of the population The key study sampled a large and representative of the U.S. general population. High

Characterization of variability Vari ability was presented in a cursory manner through calculation of summary statistics. High

Lack of bias in study design Subj ects were selected randomly from the U.S. population. High

Measurement error Inhalation rates were not measured directly. Rather, they were estimated using other measurements (i.e., activity patterns, metabolic equivalents and body weight). Measurement error is well documented by statistics, but procedures measure factor indirectly. Medium

Other Elements Number of studies One key study contributed the recommended values; five additional relevant studies were evaluated. Low

Agreement between researchers There is general agreement among researchers using different experimental methods. High

Overall Rating Recommendations are based on one study not yet published, but it is the most recent data and scientific methodology available. Medium

### 7-37 Table 7-21. Summary of Recommended Values For Inhalation

Activity Level Age Range (years) Males Females
Mean m 3 /day N Mean m 3 /day N Long-term Exposures (All)
(Percentiles see Tables 7- 13 and 7-14) birth to <1 year 1 to <2 years 2 to <3 years 3 to <6 years 6 to <11 years 11 to <16 years 16 to <21 years 8.76 13.49 13.23 12.65 13.42 15.32 17.22 419 308 261 540 940 1337 1241 8.53 13.31 12.74 12.16 12.41 13.44 13.59 415 245 255 543 894 1451 1182 Short-term Exposures Sleep or Nap
(Percentiles see Tables 7- 15 and 7-16) birth to <1 year 1 to <2 years 2 to <3 years 3 to <6 years 6 to <11 years 11 to <16 years 16 to <21 years 4.44 6.48 6.64 6.28 6.64 7.57 7.65 419 308 261 540 940 1337 1241 4.20 6.61 6.57 6.02 6.28 6.93 6.34 415 245 255 543 894 1451 1182 Sedentary/Passive
(Percentiles see Tables 7- 15 and 7-16) birth to <1 year 1 to <2 years 2 to <3 years 3 to <6 years 6 to <11 years 11 to <16 years 16 to <21 years 4.58 6.65 6.90 6.60 7.01 8.12 8.29 419 308 261 540 940 1337 1241 4.32 6.78 6.81 6.34 6.68 7.50 6.85 415 245 255 543 894 1451 1182 Light Intensity
(Percentiles see Tables 7- 15 and 7-16) birth to <1 year 1 to <2 years 2 to <3 years 3 to <6 years 6 to <11 years 11 to <16 years 16 to <21 years 11.43 16.65 16.80 16.36 16.76 19.04 19.31 419 308 261 540 940 1337 1241 10.54 16.73 17.27 15.72 15.94 17.31 15.96 415 245 255 543 894 1451 1182 Moderate Intensity
(Percentiles see Tables 7- 15 and 7-16) birth to <1 year 1 to <2 years 2 to <3 years 3 to <6 years 6 to <11 years 11 to <16 years 16 to <21 years 20.87 30.74 31.02 30.28 32.08 38.02 41.79 419 308 261 540 940 1337 1241 20.13 30.21 30.73 28.81 30.24 33.91 33.44 415 245 255 543 894 1451 1182 High Intensity
(Percentiles see Tables 7- 15 and 7-16) birth to <1 year 1 to <2 years 2 to <3 years 3 to <6 years 6 to <11 years 11 to <16 years 16 to <21 years 39.56 57.96 58.25 56.22 62.81 73.18 76.56 183 164 162 263 637 1111 968 34.83 52.53 54.12 49.72 56.72 67.05 63.49 79 55 130 347 707 1170 887

## APPENDIX 7A

VENTILATION DATA

### 7A-1 Table 7A-1. Mean Minute Ventilation (V e , L/min) by Group and Activity for Laboratory Protocols Activity Young Children a Children a Lying Sitting Standing 6.19 6.48 6.76 7.51 7.28 8.49 Walking 1.5 mph 1.875 mph 2.0 mph 2.25 mph 2.5 mph 3.0 mph 3.3 mph 4.0 mph 10.25 10.53 DNP 11.68 DNP DNP DNP DNP DNP DNP 14.13 DNP 15.58 17.79 DNP DNP Running 3.5 mph 4.0 mph 4.5 mph 5.0 mph 6.0 mph DNP DNP DNP DNP DNP 26.77 31.35 37.22 DNP DNP

a Young Children, male and female 3-5.9 years old; Children, male and female 6-12.9 years old;
DNP: group did not perform this protocol or N wa s too small for appropriate mean comparisons.
Source: Adams , 1993

### 7A-2 Table 7A-2. Mean Minute Ventilation (V e , L/min) by Group and Activity for Field Protocols

Activity a Young Children b Children b
Play 11.31 17.89

a Activities for which groups did not perform the protocol or N was too small for appropriate mean comparisons were car driving, car riding, yardwork, housew ork, car maintenance, mowing, and woodworking.

b Young Children, male and female 3-5.9 years old; Children, males and females 6-12.9 years old.
Source: Adams, 1993

Table 7A-3. Statistics of the Age/gender Cohorts Used to Develop Regression Equations for Predicting Basal Metabolic Rates (BMR)

Gender, Age (years) BMR CV Body Weight

(kg) N BMR Equation a r
MJ d -1 SD

Males Under 3 3 to < 10 10 to < 18 1.51 4.14 5.86 0.918 0.498 1.171 0.61 0.12 0.20 6.6 21 42 162 338 734 0.249 bw - 0.127 0.095 bw + 2.110 0.074 bw + 2.754 0.95 0.83 0.93
Females Under 3 3 to < 10 10 to < 18 1.54 3.85 5.04 0.915 0.493 0.780 0.59 0.13 0.15 6.9 21 38 137 413 575 0.244 bw - 0.130 0.085 bw + 2.033 0.056 bw + 2.898 0.96 0.81 0.8

a Body weight (bw) in kg SD: Standard deviation. CV: Coefficient of variation (SD/mean) r: coefficient of correlation
Source: Layton, 1993