~ 

ft EA~ United States Environmental Protection 

"' Agency 

Age Dependent 

Adjustment Factor 

(ADAF) Application 

Office of Water Policy Document 
Age Dependent Adjustment Factor (ADAF) Application 

Office of Water Policy Document 

U.S. Environmental Protection Agency 

Office of Water (4304T) 

Health and Ecological Criteria Division 

Washington, DC 20460 

www.epa.gov/safewater/ccl/pdf!XXXX.pdf 

EPA Document Number: 

Date: March 2011 

2 
AUTHORS, CONTRIBUTORS AND REVIEWERS 

Joyce M. Donohue, Ph.D. 

Health and Ecological Criteria Division 

Office of Water 

U.S. Environmental Protection Agency 

Melissa J. Simic, MS 

Health and Ecological Criteria Division 

Office of Water 

U.S. Environmental Protection Agency 

INTERNAL EPA REVIEWERS 

Brenda F oos, MS 

Office of Children's Health Protection 

U.S. Environmental Protection Agency 

Edward V. Ohanian, Ph.D., 

Associate Director for Science 

Office of Water 

U.S. Environmental Protection Agency 

Rita Schoeny, Ph.D. 

Senior Science Advisor 

Office of Water 

U.S. Environmental Protection Agency 

3 
1.0 Background 

The Environmental Protection Agency Guidelines for Carcinogen Risk Assessment (EPA, 

2005b) require the consideration of the possibility of risks for cancer from early life stage 

exposure. In particular, the Guidelines recommend that life stage-specific, cancer slope 

factors be calculated when the data permit. In the absence of such data, the Guidelines 

specify the application of Age Dependant Adjustment Factors (ADAFs) in determining 

tumorigenic risk for chemicals that have a demonstrated mutagenic mode of action 

(MOA). In cases where it is not possible to determine that the response to dose is 

nonlinear through an identified MOA, EPA has chosen to use a default of low dose linear 

extrapolation without ADAF. 

The Office of Water (OW) has yet to apply the ADAF guidance in any of its regulatory 

risk-based assessments of chemical contaminants under the 1996 Safe Drinking Water 

Act (SDWA) related activities. As part ofthe IRIS training for the Agency Reviewers, 

the National Center for Environmental Assessment (NCEA) indicated that IRIS 

documents would include a statement as to the advisability of inclusion of the ADAF in a 

Program Office risk assessment, but that the policies for its application would be 

developed by the Program Office. 

This document was prepared for the purpose of establishing the policies the OW will 

follow when applying the ADAFs in the quantification of the risk of drinking water 

exposures from mutagenic carcinogens. Application of the ADAFs has no impact on the 

Maximum Contaminant Level Goal (MCLG) because it is zero for all carcinogens that 

lack a demonstrated non-mutagenic mode of action. On the other hand, the Maximum 

Contaminant Level (MCL) is based on technical (analytical and treatment limitations) 

and cost-benefit considerations which consider risk as an important benchmark in its 

determination. The MCL is generally selected so that the cancer risk falls within the onein ten thousand to one-in-million risk range. 

The Supplemental Guidance for Assessing Susceptibility from Early-Life Exposure to 

Carcinogens (EPA, 2005a) was published at the same time as the Cancer Guidelines. 

This document reviewed existing data for chemicals with early life exposures and 

concluded that exposure to chemical carcinogens with a mutagenic MOA are likely to 

increase incidence or reduce latency for cancer by comparison to exposures that begin 

after attainment of developmental maturity. The document recommends that when 

considering childhood exposure, ADAFs be applied to cancer slope factors calculated 

from studies (bioassay or epidemiological) that involve only adult exposures. Three age 

periods are delineated for the ADAFs; each is associated with a numeric value for the 

increase in risk during that age period. These are to be used with age-specific exposure 

information in risk characterization. The three age periods and their associated ADAFs 

are as follows: 

• Birth to less than age 2 years: a I 0-fold increase in slope factor (2 year duration) 

• Age 2 to less than age 16: a 3-fold increase in slope factor (14 year duration) 

4 
• Age 16 to 70 years: risk as calculated from the adult only exposure (54 year 

duration). 

The equation for the calculation of risk is as follows: 

Risk = CSF x ADAF x dose (mg/kg/day) x exposure duration/70 years 

Where: 

CSF = Cancer Slope Factor (mg/kg/day)" 1 

The risk is calculated for each of the three exposure periods with application of its ADAF 

and then added together to obtain the total risk for a 70 year period initiated at birth. 

Risks can also be calculated for any exposure duration of interest combined with the 

doses for the age group of interest. 

2.0 Consideration of Variables for the Office of Water (OW) Calculations 

Drinking water is the exposure medium of concern for the OW. The following sections 

explain the OW policy development process and subsequent policy recommendations. 

The OW considered the following variables in the development of their policies: 

normalization of drinking water intakes and body weights (independent versus ratio), 

percentile level for analysis (90th versus 95th), and selection of drinking water intakes (all 

individuals versus consumer-only). 

2.1 Normalization of Drinking Water Intakes and Body Weights across the 

ADAF Ages 

For drinking water the dose for each of the three exposure durations will vary with the 

normalized water intake and the normalized body weight of the individual over the 

specified time period. The information needed to determine the normalized drinking 

water intakes and body weights can be identified in the Child-Specific Exposure Factor's 

Handbook (EPA, 2008) and the OW Estimated Per Capita Water Ingestion in the United 

States (EPA, 2004). In both cases the values presented are derived from the USDA 

Continuing Survey of Food Intakes by Individuals (CSFII 1994-1996 and 1998). 

There are several policy options that the OW can consider in obtaining the dose (water 

intake and body weight) estimates. They are as follows: 

Approach 1: Use independent body weight (kg) and water intake (Liday) values 

Approach 2: Use ratio of water intake to body weight in terms ofL/kg/day 

For the first approach the statistical analysis of body weights and water intakes of the 

populations were evaluated independently. For the second measure, the ratio of water 

intake to body weight was determined for each individual in the population and the ratios 

were analyzed statistically. 

5 
The differences between the two data sets for the two normalization approaches can be 

described as follows: 

• Approach 1 : The distributions for body weight were derived from all of the body 

weight data in the CSFII without consideration of the water intake associated with 

each body weight. The situation was similar for the distribution of the drinking 

water intake information. The analysis was derived for each measure of drinking 

water intake without consideration of the body weight associated with each intake. 

• Approach 2: The ratio data are linked at the level of the individual rather than the 

population. The analysis of the exposure values using the Llkg body weight 

measures is based on a set of monitoring values in which the water intake of each 

study participant was first divided by their body weight before completing the 

statistical analysis of the data. 

The OW consulted the Office of Children's Health Protection (OCHP) on the approach to 

use for normalizing body weights and drinking water intakes across the age range for 

each of the ADAF periods. The OCHP recommended that the product of each agespecific variable multiplied by the its fraction of the total duration be summed to obtain 

the normalized drinking water intake, body weight, and L drinking water/kg body weight 

variables for each ADAF age period. It was further recommended that the Child Specific 

Exposure Factors Handbook (U.S. EPA, 2008) be used as the source for the body weight 

and exposure variables. Table 1 provides an example for normalization of body weights 

across the four age subgroupings within the 2 year to <16 year age period using the body 

weight values from the Child-specific Exposure Factor's Handbook (2008). In order to be 

consistent with the data source for the drinking water intakes (CSFII)], the OW has used 

the mean body-weight data from Kahn and Stralka (2008), Table 8-24 in EPA (2008), in 

place ofthe data derived from the NHANES 1999-2006 data (EPA [2008] Table 8-1). 

Table 1: Normalized Body Weight for t he 2-year to 16 year Age Period (Kahn and 

Stralka, 2008) Table 3-24 (EPA, 2008) 

Age Range Body Weight Duration Product (body wt. x duration 

Years kg Fraction fraction) 

years k2 

2 to <3 14 1114 1 

3 to <6 18 3/14 3.857 

6 to <11 30 5/14 10.714 

11to<16 54 5/14 19.286 

Normalized value (sum of the age specific products) 34.857 

The same approach (i.e. multiplication of the variable by the fraction ofthe ADAF age 

period and summing the results) is used for each of the ADAF age groups and each of the 

variables (body weight, drinking water intakes or L drinking water/ Kg body weight ) 

needed for the calculations. Tables 1 through 9 in the supporting data attachment show 

the derivation of the normalized values for body weight, drinking water intake, and 

6 
drinking water intake body weight ratios for each of the three ADAF age groupings using 

the data from EPA (2008) and EPA (2004). 

In order to illustrate the impact of variable selection, OW calculated the unit risk and total 

70 year unit risk after application of the ADAFs for the 90th percentile consumer-only 

direct and indirect water intakes and average body weights (Table 2) as compared to the 

values calculated using drinking water intake body weight ratios (Likg/day) using the 

same assumptions (Table 3). Both sets of calculations are based on a sample CSF of 21 

(mg/kg/dayr1

• The unit risk is defined as the risk associated with a drinking water 

concentration of 1 1-1g/L (0.001 mL/day). 

Table 2: Approach 1- Unit Risk Derived from 90tn Percentile Drinking Water 

Intakes and Avera~e Body Wei~hts {CSF = 21/mwkwday) 

Unit Risk= CSF x ADAF x DWI/bw x 0.001 mg/L x Exposure Duration/70 years 

Age Range Body Weight ADAF Drinking Exposure Unit Risk 

years (bw) Water Intake Duration 1-lg/L 

kg (DWI) years 

L/day 

Birth to< 2 9.71 10 0.861 2/70 5.320 X 104 

2 to< 16 34.857 3 1.012 14/70 3.658 X 10-4 

16 to 70 75.277 1 2.237 54/70 4.814 X 10-4 

Total unit risk 1.379 x 1 o-J 

Table 3: Approach 2- Unit Risk Derived from 901n Percentile Drinking Water 

Intakes Average Body Weight Ratios (CSF = 21/mg/kg/day) 

Unit Risk= CSF x ADAF x DWI/bw Ratio x 0.001 mg/L x Exposure Duration/70 years 

Age Range Drinking Water ADAF Exposure Unit Risk Jlg/L 

Intake I body Duration 

weight ratio years 

L/kWday 

Birth to< 2 0.104 10 2/70 6.240 X 104 

2 to< 16 0.037 3 14/70 4.662 X 10-4 

16 to 70 0.032 1 54/70 5.184 X 104 

Total unit risk 1.609 x 1 o-J 

The total unit risk values can be converted to the concentration in drinking water 

equivalent to a 1 X 1 Q-6 risk USing the following equation: 

Concentration (!lg/L) at 1 X 10-6 risk = 1 X w-6 7 unit risk (Jlg/Lr 1 

7 
The concentration equivalent to a one-in-a million risk for a 70 year exposure initiated at 

birth as calculated in Table 2 is 0.000725 ~giL rounded to 0.7 ng!L 

The concentration equivalent to a one-in-a million risk for a 70 year exposure initiated at 

birth as calculated in Table 3 is 0.000622 ~giL rounded to 0.6 ng/L. 

Tables 2 and 3 demonstrate the difference in one-in-a-million risk concentrations for a 70 

year exposure initiated at birth based on the using two different data sets to represent the 

relationship between drinking water intakes and body weights. It is the OW policy to 

express the fmal risk value using one significant figure. 

2.1 Percentile Level for Analysis 

A second variable that was considered for the OW policy development process was the 

percentile level to select for the analysis: 90th versus 95th. The OW has traditionally used 

an adult body weight of70 kg (once a mean value) and a 2 Llday water intake (-90th 

percentile) in its chronic exposure assessments for cancer endpoints. The Child-Specific 

Exposure Factor's Handbook (EPA, 2008) recommends that the 95th percentile values be 

used. However, as per EPA (2008) the 95th percentile values are problematic for some 

age groups because the sample size (CSFII (1994-1996, 1998) did not meet minimum 

requirements as described in the third report on nutrition monitoring in the United States. 

Although this is also the case at the 90th percentile, fewer groups are affected. For 

example, the minimum requirements are not met for data on water consumption from 

birth to 6 months and ages 16-21 years at the 95th percentile with the direct and indirect 

water intake estimates for consumers only (EPA, 2008). At the 90th percentile value only 

the birth to <3 month groups fail to meet the size requirement. 

2.3 Selection of Drinking Water Intakes 

Another variable for consideration is selection of the drinking water intakes for all 

individuals or for consumers only. The earlier OW defaults of2 Ll day for adults and 1 

Llday for children were approximate estimates for the 901

h percentile of all individuals in 

a study by Ershow and Cantor (1989) which were reaffirmed in the analysis that 

produced the updated evaluation of population drinking water intakes based on the most 

recent CSFII data( EP A(2004). These estimates are not appropriate in carrying out the 

ADAF evaluations wherein age-specific intakes are needed. Several ongoing assessments 

which do not involve cancer have used the consumers-only data as the preferred values to 

protect sensitive populations. It is the recommendation of this document to continue use 

of the more recent consumers-only policy. 

3.0 Calculating Risk for a Less than Lifetime Exposure 

As mentioned above, the ADAF's allow the user to calculate risks for a less than lifetime 

exposure such as the first 7 years of life. Seven years is the age period used by the OW 

in the derivation of the longer-term health advisory for a child because that is frequently 

the duration granted by a variance or exemption for a public drinking water system to 

8 
achieve the MCL for a regulated contaminant. Table 4 provides an example of the risk 

calculation for this exposure period using the drinking water intake/body weight ratio. 

Table 5: Unit Risk Derived from 90th Percentile Drinking Water Intake Average 

Body Weight Ratios for a Birth to 7-year Exposure (CSF = 21 /mg!kg!day) 

Unit Risk= CSF x ADAF x DWI/bw Ratio x 0.001 mg/L x Exposure Duration/70 years 

Age Range Drinking Water ADAF Exposure Unit Risk J.lg/L 

Intake I Body Duration 

Weight Ratio years 

L/kglday 

Birth to < 2 0.104 10 2170 6.240 X 0-'~ 

2 to< 7 0.046 3 5170 2.070 X 10-4 

Total unit risk 8.310 xl0-4 

The concentration equivalent to a one-in-million risk for developing cancer during a 70 

year lifetime with an exposure that lasts from birth to age 7 is calculated by dividing the 

total unit risk into 1 x 10-6. The resultant value is 0.00120 J.lg/L rounded to I ng/L. 

Calculating this value makes it possible to compare the cancer risk for such an exposure 

to the longer term health advisory for non-cancer effects. Providing estimate of the 

lifetime cancer risk for a longer term exposure as well as a value protective for noncancer effects from the same exposure provides important information to the risk 

manager during decision making for mutagenic chemicals present in public drinking 

water supplies. 

4.0 Internal Peer Review 

The preceding portions of this document were reviewed by Rita Schoeny of the OW and 

Brenda Foos of the Office of Children's Health Protection (OCHP). Recommendations 

of the peer reviewers were accommodated in the revisions to the draft document. 

Additional input on evolving policies related to perchlorate was provided by Eric 

Bumeson ofthe Office of Groundwater and Drinking Water (OGWDW). Other 

alternatives to this process were suggested by the OCHP during the internal review of this 

document. They are as follows: 

• Use the data from all 11 child-specific age periods as provided by the EPA (2008) 

combined with 20+ data from (EPA, 1004) derived from the same CSFII data set 

rather than the compressed three data sets. 

• Work with the ORD Exposure researchers to obtain appropriate values for the 

three ADAF age periods from the CSFII (1994-1996, 1998) data directly. 

The OW feels that communication of the ADAF adjustment to its stakeholder community 

is facilitated by a presentation using the three age groupings as established by the ADAF 

9 
guidelines. Once the policy decisions related to drinking water intake and body weight 

relationships for each of the age groups have been established they will be a constant for 

the calculation, simplifying presentation and supported by a citation to this document. 

The first OCHP suggestion could be accommodated in an appendix to the OW reports for 

those who desire refined breakdown of the individual impacts for the 12 component age 

ranges. Postponing the application of the ADAFs until ORD could reanalyze the original 

data would be preferred if they would be able to do it within a time period where it could 

be used for Regulatory Determinations 3, but that is unlikely. 

5.0 Recommendation 

After considering the options discussed above, the OW recommends the use of the 90th 

percentile consumers-only drinking water intake body weight ratio data (Likg/day) when 

applying ADAFs to risk values for carcinogens with an established mutagenic mode of 

action. The 901h percentile data were selected because, for all but the birth to < 3 

month age groupings, the population size was sufficient for the drinking water intake 

body weight ratio analysis thereby minimizing the uncertainty in the values. Use of the 

90th percentile is consistent with the long term OW policy. Use of the consumers-only 

values insures that the resultant risk values are applicable for those totally reliant on 

drinking water (direct and indirect) from public drinking water systems. The ratio data 

are preferable to using the body weight and water intake parameters separately because 

the two parameters are linked at the level of the individual rather than the population. 

6.0 References: 

Ershow, A.G., and K.P. Cantor. 1989. Total water and tapwater intake in the United 

States: population-based estimates of quantities and sources. National Cancer Institute 

Contract No. 263-MD-81 0264. Life Sciences Research Office. Federation of American 

Societies for Experimental Biology. Bethesda, MD. 

U.S. Environmental Protection Agency (USEPA) 2004. Estimated Per Capita Water 

Ingestion in the United States. Office of Water. U.S. Environmental Protection Agency. 

Washington, CD. EPA. 822-R-00-001. 

http://water.epa.gov/action/advisories/drinking/upload/2005 05 06 criteria drinking per 

capita 2004.pdf 

U.S. Environmental Protection Agency (USEPA). 2005a. Guidelines for carcinogen risk 

assessment. Risk Assessment Forum, U.S. Environmental Protection Agency, 

Washington, DC. EPA/630/P-03/00lF. 

http:/ /cfuub.epa.gov/ncea/cfm/recordisplay.cfm ?deid= 116283 

U.S. Environmental Protection Agency (USEPA). 2005b. Supplemental Guidance for 

Assessing Susceptibility from Early-Life Exposure to Carcinogens. Risk Assessment 

Forum, U.S. Environmental Protection Agency, Washington, DC. EPA/630/R-03/003F. 

http://www.epa.gov/ttnlatw/childrens supplement final.pdf 

10 
U.S. Environmental Protective Agency (USEPA). 2008. Child-Specific Exposure 

Factors Handbook. National Center for Environmental Assessment. Office of Research 

and Development. Washington, DC. EP A/600RJR-06/096F. 

http://cfpub.epa.gov/ncealcfm/recordisplay.cfm?deid=56747 

11 
Supporting Information 

The supplemental information describes how drinking water intake and body weight were 

normalized based on age ranges for the three ADAF adjustment periods. The OW 

believes that the normalization of the body weight and drinking water intake data across 

the three age periods specified in the ADAF guidance document rather than including 

calculations for each of the eleven age periods included in the Child-Specific Exposure 

Factors Handbook simplifies the presentation of the data for stakeholders without having 

a substantial impact on the outcome of the analysis. 

Body Weights: Approach 1 

Table 1: Normalized Body Weight for the Birth to< 2-year Age Period EPA, 2008 

Table 8-24) 

Age Range Body Weight Duration Fraction Product 

Months kg kg 

Birth to <1 4 1124 0.167 

1 to <3 5 2/24 0.417 

3 to <6 7 3/24 0.875 

6 to< 12 9 6/24 2.250 

12 to <24 12 12/24 6.000 

Normalized value (sum of the age specific numbers) 9.71 

Table 2: Normalized Body Weight for the 2-year to <16-year Age Period EPA, 2008 

Table 8-24) 

Age Range Body Weight Duration Fraction Product 

Years kg kg 

2 to <3 14 1/14 1 

3 to <6 18 3/14 3.857 

6 to <1 1 30 5/14 10.714 

llto<16 54 5/14 19.286 

Normalized value (sum ofthe age specific products) 34.857 

Table 3: Normalized Body Weight for the 16-year to 70-year Age Period (EPA, 2008 

Table 8-24; EPA, 2004 Table 7.2 

Age Range Body Weight Duration Fraction Product 

Years kg kg 

16 to <18 67 2/54 2.481 

18 to <21 69 3/54 3.833 

20+ 76 49/54 68.963 

Normalized value (sum of the age specific numbers) 75.277 

12 
Drinking Water Intakes: Approach 1 

Table 4: Consumers only direct and indirect drinking water intakes normalized for 

the birth to <2-year Age Period (EPA, 2008 Table 3-14) 

Age Range Drinking Water Intake Duration Product 

Months L/day Fraction L/day 

Birth to <1 0.849* 1/24 0.035 

I to <3 0.943* 2/24 0.079 

3 to <6 1.021 3/24 0.128 

6 to< 12 0.971 6/24 0.243 

12 to <24 0.674 12/24 0.337 

Normalized value (sum of the age specific numbers) 0.822 

Table 5: Consumers only direct and indirect drinking water intakes normalized for 

the 2-year to 16-year Age Period (EPA, 2008 Table 3-14) 

Age Range Drinking Water Intake Duration Product 

Years L/day Fraction L/day 

2 to <3 0.700 1/14 0.050 

3 to <6 0.867 3114 0.186 

6 to <11 0.994 5114 0.355 

11 to< 16 1.432 5114 0.511 

Normalized value (sum of the age specific numbers) 1.102 

Table 6: Consumers only direct and indirect drinking water intakes normalized for 

the 16-year to 70 year Age Period (EPA, 2008 Table 3-14; EPA, 2004 Table A2 P. E100) 

Age Range Drinking Water Intake Duration Product 

Years L/day Fraction L/day 

16 to <18 1.647 2/54 0.061 

18 to <21 1.860 3/54 0.103 

21 to 70 2.284 49/54 2.073 

Normalized value (sum ofthe age specific numbers) 2.237 

13 
Drinking Water Intake Body Weight Ratios: Approach 2 

Table 7: Consumers only direct and indirect drinking water intake/body weight 

ratios normalized for the birth to <2 year Age Period (EPA, 2008 Table 3-19) 

Age Range Drinking water intake/ Duration Product 

Months body weight ratio Fraction L/kglday 

Llkg/day 

Birth to <1 0.235 1/24 0.010 

1 to <3 0.228 2/24 0.019 

3 to <6 0.148 3/24 0.019 

6 to< 12 0.112 6/24 0.028 

12 to <24 0.056 12/24 0.028 

Normalized value (sum of the age specific numbers) 0.104 

Table 8: Consumers only direct and indirect drinking water intake/body weight 

ratios normalized for the 2-year to 16 year Age Period (EPA, 2008 Table 3-19) 

Age Range Drinking Water Intake/ Duration Product 

Years body weight ratio Fraction Llkglday 

L/kg/day 

2 to <3 0.052 1114 0.004 

3 to <6 0.049 3/14 0.011 

6 to <11 0.035 5/14 0.013 

11 to< 16 0.026 5/ 14 0.009 

Normalized value (sum of the age specific numbers) 0.037 

Table 9: Consumers only direct and indirect drinking water intake/body weight 

ratios normalized for the 16-year to 70 year Age Period (EPA, 2008 Table 3-19; 

EPA, 2004 Table A1 page E 139) 

Age Range Drinking Water Intake/ Duration Product 

Years body weight ratio Fraction Llkg!day 

L/kg/day 

16 to <18 0.024 2/54 0.001 

18 to <21 0.029 3/54 0.002 

20+ 0.032 49/54 0.029 

Normalized value (sum of the age specific numbers) 0.032 

14 
Birth to Seven Year Exposure Using a Drinking Water Intake/ Body Weight Ratio: 

Approach 2 

Table 10: Consumers only direct and indirect drinking water intake/body weight 

ratios normalized for the 2-year to <7 year Age Period (EPA, 2008 Table 3-19) 

Age Range Drinking Water Intake/ Duration Product 

Years body weight ratio Fraction Llkg/day 

Llkg/day 

2 to <3 0.052 1/5 0.010 

3 to <6 0.049 3/5 0.029 

6 to <7 0.035* 115 0.007 

Normalized value (sum of the age specific numbers) 0.046 

*Value applies to the 6 to <11 age range as reported in the Exposure Factor's Handbook 

15 
Child-Specific Exposure Factors Handbook 

Chapter 8- Body Weight 

Table 8-23. Estimated Body Weights of Typical Age Groups of Interest in U.S. EPA Risk Assessments' 

Age Group NHANES Males (kg) Females (kg) Overall (kg) 

Mean so N Mean so N Mean so N 

n 17.0 4.6 2.097 16.3 4.7 1,933 16.7 4.5 4,030 

I to 6 years Ul 16.9 4.7 3,149 16.5 4.9 3,221 16.8 5.0 6.370 

IV 17.1 4.9 633 17.5 5.0 541 17.3 5.0 1,I74 

IJ 45.2 17.6 1,6 18 43.9 15.9 I,507 44.8 17.5 3.125 

7 to 16 years lii 49.3 20.9 2,549 46.8 18.0 2,640 47.8 18.4 5,189 

IV 47.9 20.1 1,203 47.9 19.2 1,178 47.7 19.1 2,381 

. Estimates were weighted using the sample weights provided with each survey . 

so ~ Standard Deviation. 

N = Number of individuals. 

Source: Portier et a!. 2007. 

Table 8-24. Estimated Percentile Distribution of Body Weight by Fine Age Categories Derived From 1994-96, 1998 CSFU 

Weight (kilograms) 

Age Group Sample Mean Percentile 

Si7-e I" 5'" 10'" 25'" 50'" 75'. QO'h 95'" 99'b 

Birth to I month 88 4 I' 2' 3' 3 3 4 4' 5' 5' 

I to <3 months 245 5 2" 3' 4 4 5 6 6 7' 8" 

3 to <6 months 411 7 4' 5 5 6 7 8 9 10 12' 

6 to <12 months 678 9 6' 7 7 8 9 10 II 12 13' 

I to <2 years 1,002 I2 8' 9 9 10 II 13 14 15 19' 

2 to <3 years 994 14 10' 10 11 12 14 16 18 19 22" 

3 to <6 years 4,112 I8 II 13 13 16 18 20 23 25 32 

6 to <II years 1.553 30 16' 18 20 23 27 35 4 1 45 57' 

I I to<l6years 975 54 29' 33 36 44 52 61 72 82 95' 

16to<l8 years 360 67 41" 46' 50 56 63 73 86 100' 114' 

18 to <21 years 383 69 45' 48' 51 58 66 77 89 100' 117' 

. Sample size does meet minimum reporting requirements as described in the "Third Report on Nutrition Monitoring in 

the United States" (LSRO, 1995). 

Source: Kahn and Stralka, 2008. 

Child-Specific Exposure Factors Handbook 

September 2008 

Page 

8-35 
Child-Specific Exposure Factors Handbook 

Chapter 3 - Water Ingestion 

Table 3-14. Consumers Only" Estimates of Combined Direct and Indirectb Water Ingestion: Community Water 

(rnUday) 

Age Sample Mean Percentiles 

size 10 25 50 75 90 95 99 

Birth to <I month 40 470* 32* 215* 482* 692* 849* 858* 919* 

I to <3 months 114 552 67* 339 533 801 943* 1,053* 1,264* 

3 to <6 months 281 556 44 180 561 837 1,021 1,171* 1,440* 

6 to <12 months 562 467 44 105 426 710 971 1,147 1,586* 

I to <2 years 916 308 43 107 229 428 674 893 1,248* 

2 to <3 years 934 356 49 126 281 510 700 912 1,388* 

3 to <6 years 3,960 417 57 146 336 581 867 1,099 1,684 

6 to <II years 1,555 480 74 177 373 682 994 1,251 2,024* 

11 to < l6 years 937 652 106 236 487 873 1,432 1,744 2,589* 

16 to <18 years 341 792 106 266 591 987 1,647 2,002* 3,804* 

18 to <21 years 364 895 114 295 674 1,174 1,860 2,565* 3,917* 

. Excludes individuals who did not ingest water from the source during the survey period . b Direct water defined as water ingested directly as a beverage; indirect water defined as water added in the 

preparation of food or beverages. 

* The sample size does not meet minimum requirements as described in the "Third Report on Nutrition 

Monitoring in the United States" (LSRO, 1995). 

Source: Kahn and Stralka, 2008 and supplementary data. 

Table 3-15. Consumers Only" Estimates of Combined Direct and lndirectb Water Ingestion: Bottled Water (mUday) 

Sample Mean Percentiles 

Age size 10 25 50 75 90 95 99 

Birth to <I month 25 - - - - - - - -

I to <3 months 64 450* 3 1* 62* 329* 743* 886* 1,045* 1,562* 

3 to <6 months 103 507 48* 88 493 747 1,041* 1,436* 1,506* 

6 to <12 months 200 425 47 114 353 630 945* 1,103* 1,413* 

1 to <2 years 229 262 45 88 188 324 600 709* 1,083* 

2 to <3 years 232 352 57 116 241 471 736 977* 1,665* 

3 to <6 years 1,021 380 72 149 291 502 796 958 1,635* 

6 to <II years 332 430 88 168 350 557 850 1,081* 1,823* 

11 to <16 years 192 570 116* 229 414 719 1,162* 1,447* 2,705* 

16 to <18 years 63 615* 85* 198* 446* 779* 1,365* 1,613* 2,639* 

18 to <2 1 years 97 769 118* 236 439 943 1,788* 2,343* 3,957* 

. Excludes individuals who did not ingest water from the source during the survey period . b Direct water defined as water ingested directly as a beverage; indirect water defined as water added in the 

preparation of food or beverages. 

- Insufficient sample size to estimate mean and percentiles. 

* The sample size does not meet minimum requirements as described in the ''Third Report on Nutrition 

Monitoring in the United States" (LSRO, 1995). 

Source: Kahn and Stralka, 2008 and supplementary data. 

Page 

3-20 

Child-Specific Exp osure Factors Handbook 

September 2008 
Child-Specific Exposure Factors Handbook 

Chapter 3- Water Ingestion 

Table 3-19. Consumers Only" Estimates of Direct and Indirectb Water Ingestion: Community Water (mL!kg-day) 

Age Sample Mean 

Percentiles 

size 10 25 50 75 90 95 99 

Birth to <I month 37 137* I I* 65* 138* 197* 235* 238* 263* 

I to <3 months 108 119 12* 71 107 151 228* 285* 345* 

3 to <6 months 269 80 7 27 77 11 8 148 173* 222* 

6 to < 12 months 534 53 5 12 ..iZ 81 ill 129 186* 

I to <2 years 880 27 4 9 20 36 56 75 109* 

2 to <3 years 879 26 4 9 21 36 52 62 121* 

3 to <6 years 3,703 24 3 8 19 33 49 65 97 

6 to <11 years 1,439 17 3 6 13 23 35 45 72* 

11 to <16 years 911 13 2 5 10 17 26 34 54* 

16 to <18 years 339 12 I 4 9 16 24 32* 58* 

18 to <21 years 361 13 2 5 !Q 17 29. 35* 63* 

• Excludes individuals who did not ingest water from the source during the survey period . b Direct water defined as water ingested directly as a beverage; indirect water defined as water added in the 

preparation of food or beverages. ... The sample size does not meet minimum requirements as described in the "Third Report on Nutrition 

Monitoring in the United States" (LSRO, 1995). 

Source Kahn and Stralka, 2008 and supplementary data. 

Table 3-20. Consumers Only" Estimates of Direct and lndirectb Water Ingestion: Bottled Water (rnUkg-day) 

Age Sample Mean Percentiles 

size 10 25 50 75 90 95 99 

Birth to <I month 25 - - - - - - - - I to <3 months 64 92* 7* 12* 76* 151* 164* 220* 411* 

3 to <6 months 95 72 6* 15 69 100 149* 184* 213* 

6 to <12 months 185 47 5* 11 34 73 104* 120* 166* 

I to <2 years 216 22 5 8 16 27 49 66* 103* 

2 to <3 years 2 11 25 4 8 17 35 54 81 * 91 * 

3 to <6 years 946 21 4 8 16 29 45 57 90* 

6 to <I I years 295 IS 3 5 II 19 30 42* 69* 

11 to <16 years 180 I I 2* 4 8 14 24* 27* 44* 

16 to <18 years 63 10* I* 3* 7* II * 23* 27* 37* 

18 to <21 years 93 I I 2* 3 6 14 27* 30* 54* 

• Excludes individuals who did not ingest water from the source during the survey period . b Direct water defined as water ingested directly as a beverage; indirect water defined as water added in the 

preparation of food or beverages. 

- Insufficient sample size to estimate means and percentiles. 

• The sample size does not meet minimum requirements as described in the "Third Report on Nutrition 

Monitoring in the United States" (LSRO, 1995). 

Source: Kahn and Stralka, 2008 and supplementary data. 

Child-Specific Exposure Factors Handbook 

September 2008 

Page 

3-23 
Gender 

b . Ma le 

c . Both sexes 

Age 

<0.5 

O.S- 0.9 

1 - 3 

4-6 

7- 1 0 

11-14 

1 5- 1 9 

20- 2 4 

25- 54 

55-64 

65 + 

20 + 

<2 

2-15 

15 + 

<6 

6-15 

All ages 

<0.5 

0.5-0 . 9 

1-3 

4-6 

7-10 

11-14 

15- 19 

20-24 

25-54 

SS-64 

65 + 

20 + 

<2 

2-15 

15 + 

<6 

6-15 

All ages 

Sampsize 

361 

333 

1,851 

1,520 

5 37 

392 

40 9 

336 

2, 499 

775 

1,114 

4,724 

1, 197 

3 ,797 

5 , 13 3 

3,79 1 

1,203 

10,127 

7 4 4 

678 

3,645 

2,988 

1,028 

790 

816 

676 

4 , 830 

1 ,516 

2,139 

9,161 

2,424 

7,449 

9, 977 

7 , 5 30 

2,343 

19,850 

Table 7. 2 . Estimated Distribution of Body Weigh t 

Gender and F i n e Age Cate g ories 

All I ndiv iduals 

Kilograms•• 

Population 

954,525 

872, 4 10 

6,127,169 

5,799,447 

7,645,20 0 

7 , 522 , 213 

9, 294 , 121 

9,172,756 

56,219,54 8 

9,564,795 

12,993,304 

87,950, 403 

3 . 917.902 

25 , 003 , 062 

97,244 ,524 

11,889,007 

17,031,957 

126,165,488 

1 , 890, 4 6 1 

1 , 7 7 0 , 7 0 0 

11,746 , 1 46 

11,570,747 

14,541,011 

15,183,156 

17,825,164 

18 , 402,877 

111,382, 8 77 

20 , 691,260 

30,578, 21 0 

181,055,224 

7,695,535 

49 , 006,686 

198,880,388 

23 , 160,174 

33,542,047 

255,582,609 

Mean 

6 

9 

14 

21 

32 

52 

7 3 

80 

85 

84 

80 

84 

10 

3 3 

8 2 

15 

40 

70 

6 

9 

1 4 

21 

32 

51 

67 

72 

77 

77 

72 

76 

10 

33 

75 

15 

4 0 

65 

P1 

3 • 

6 ' 

9• 

13• 

1 8 • 

28• 

4 4 • 

52• 

5 4 

54 • 

51• 

5 4 

3* 

11 

52 

4 

18• 

9 

2• 

6• 

8 

1 2 

17• 

28• 

42' 

4 5 • 

4 5 

46 

44 

45 

3 

11 

4 5 

4 

17 

8 

P5 

3• 

7 • 

10 

15 

21 

32• 

53 

58 

63 

61 

59 

61 

4 

13 

60 

7 

20 

15 

14 

20 

32 

47 

49 

52 

52 

so 

51 

4 

13 

so 

6 

20 

15 

P10 

4 

7 

11 

16 

22 

35 

56 

61 

66 

67 

63 

65 

6 

15 

63 

8 

22 

22 

7 

10 

16 

22 

35 

so 

53 

54 

57 

54 

54 

5 

15 

54 

8 

2 2 

22 

P25 

5 

8 

12 

1 8 

27 

4 1 

6 1 

68 

75 

74 

70 

72 

8 

1 9 

72 

11 

27 

59 

4 

8 

11 

17 

26 

4 2 

56 

59 

63 

6 5 

6 2 

6 3 

7 

19 

61 

11 

27 

52 

P50 

9 

l4 

20 

31 

50 

6 8 

78 

83 

83 

78 

82 

10 

28 

81 

15 

36 

76 

13 

20 

29 

so 

63 

68 

75 

75 

71 

73 

10 

28 

72 

l4 

36 

67 

P75 

7 

10 

16 

22 

36 

60 

80 

86 

93 

93 

88 

91 

1 2 

43 

91 

18 

so 

87 

7 

10 

16 

22 

36 

58 

73 

81 

86 

87 

81 

86 

11 

43 

84 

1 8 

50 

81 

P90 

11 

18 

26 

44 

72 

94 

100 

104 

103 

99 

104 

13 

57 

10 3 

21 

61 

100 

8 

11 

18 

26 

43 

68 

85 

9 4 

1 00 

99 

93 

98 

13 

56 

97 

2 1 

59 

95 

P9 5 

9 • 

12• 

19 

28 

4 8 

81 • 

107 

112 

111 

109 

104 

110 

1 4 

66 

109 

23 

71 

109 

9 

1 2 

19 

28 

48 

79 

99 

104 

1 09 

10 5 

100 

107 

l4 

63 

106 

23 

68 

104 

P99 

11• 

n • 23 • 

36 • 

63 ' 

92• 

116• 

134' 

131 

125 • 

117 • 

130 

1 7• 

8 4 

129 

29 

86 • 

126 

11' 

13. 

23 

36 

59• 

89• 

113 • 

130• 

127 

124 

113 

126 

17 

82 

125 

28 

as 

122 

Source of data: 1994 -1996, 1998 USDA Continuing Survey of Food Intakes by Indiv iduals(CSFII) 1SAPR03 18:59 :\ PW OS~ ATER\REQ006\R006 Gl.LST 

• : The sample size does not meet minimum reporting requirements a s described in t he "Third Repor t on Nutrition Monitoring in the Un i ted States.• -

••: Multiply val u es b y 2.2 to c onvert to estimat ed weight in p o unds. 

NOTE: 757 individ uals did not rep ort body weig ht. They represent 6 , 3 1 4,627 indiv i d ualn in the pop ulation. 

7-8 
Gender Age 

c. Both sexes 

Direct and Indirect <0.5 

0.5-0 . 9 

<2 

1-3 

4 - 6 

<6 

7-10 

11 -14 

15 - 19 

20 + 

"'20-24 

25- 54 

5 5 -64 

65 + 

All ages 

Part III : Estimates of Direct, I ndirect, and Both Direct and I ndirect Wa t er Ingest i on 

Table A2 . community Water: Gender by Fine Age Categori e s 

Consumers Only 

Millili ters/Person/Day 

Sampsize Population Mean P1 P5 P10 P25 PSO 

435 1 , 057,243 548 10* 29 52 209 552 

562 1 ,437 , 057 46 7 3* 25 4 4 105 4 26 

1,913 6,176,837 386 3 ' 22 4 4 114 301 

3,422 11,011,095 349 3 2 3 48 119 270 

2,916 11,352,187 442 4 29 61 152 355 

6,807 21,037,341 398 4 25 51 130 315 

1,027 14 , 327,436 4 87 6* 34 72 180 382 

759 1 4,432 , 607 641 7• 5 9 115 235 4 73 

777 16 , 744 ,959 817 7* 51 99 266 608 

8,611 172,088,785 1,176 13 103 208 524 995 

644 17,658,027 1.033 10 ' 68 122 359 711 

4,599 106,779,569 1 ,171 14 100 201 503 965 

1,410 19 , 484 ,112 1 , 242 11 115 237 651 1,111 

1 , 958 28, 167' 077 1. 242 24 155 310 704 1. 149 

18, 509 242,451,369 1 , 000 9 64 127 355 786 

II!-8 

P75 P90 P95 P99 

814 985 1,139 1 ,433• 

710 971 l , 14 7 1 ,586* 

587 856 1, 0 14 1, 4 01* 

485 723 946 1,393 

607 943 1,176 1,729 

564 842 1 ,051 1, 5 73 

707 993 1 , 241 1 , 9 42 * 

8 33 1, 415 1 ,74 2 2 , 564 * 

1,065 1 ,671 2 ,161 3, 862 * 

1,572 2,284 2,848 4,631 

1,218 2,175 3,082 5, 356 * 

1,561 2,326 2,926 4 , 7 35 

1 , 657 2 , 297 2 , ?21 4,222 

1. 657 2, 190 2 , 604 3,668 

1,375 2,069 2, 601 4 , 2 74 

Source of data: 1994-1996, 1998 USDA Continuing Survey of Food Intakes by Individuals(CSFII) 19FEB04 09:04 M:\PW\OSTWATBR\REQ006\R006_ E4.LST 

Estimates are b ased on 2-day averages. 

Al l estimates exclude commer cial and b i o l ogical wa ter . 

Means ze r o. 

• : Th e sample s ize does not meet minimum r eporting requirements as described in the "Third Report on Nutrition Monitoring in the United States. " 

E-100 
Part IV: Esti mates o f Direct, Ind i r ect, and Bot h Direct and I ndirect Water Ingestion IV-2 

Table A1 . Community Water: Gender by Broad Age categories 

Consurr.ers Only 

Mi lliliters/Kg of Body Weight/Day 

Gender Age Sampsize Population Mean Pl PS PlO P25 PSO P7S P90 P9S P99 

c. Both sexes 

Direct < 1 398 1 , 012,461 18 p 2 • 3 5 11 23 39 57• 117• 

1-10 5 , 087 26 , 870,324 17 1 2 3 6 12 22 36 4 7 78 

11-19 1,245 25,303,467 11 1* 1 2 4 8 13 22 28 58* 

20 • 6,583 130. 511,025 11 1 1 2 " 8 14 23 30 so All ages 13,313 183,697,277 12 1 1 2 4 8 15 25 33 57 

Indirece < 1 898 2,247,324 67 1* 2 5 12 57 100 1 4 1 172 249• 

1 - 10 6,331 30 ,701,858 a 1 2 6 11 19 26 45 

11-19 1,282 26 , 304,246 5 - - - 1 3 6 10 14 25* 

20 • 8,055 160,396,393 8 1 3 6 11 17 22 39 

All ages 16,566 219,649,821 8 - - 1 2 6 11 17 23 51 

Direct a nd Indirect < 1 948 2,373,335 71 1* 3 6 17 62 106 145 185 2 61* 

1-10 6 , 901 34 ,527,957 21 1 3 7 16 28 44 57 n 11 -19 1. 507 30 , 759,097 13 1 2 4 10 17 26 34 60* 

20 + 8, 459 168 ,957,363 16 1 3 7 13 22 32 39 62 

All ages 17,815 236.617. 752 17 - 1 3 7 13 22 33 44 77 

Source of data: 1994- 1996 , 1998 USDA Continu i ng Survey of Food Intakes by Indiv i duals(CSFII) 

Est i mates are b a s e d on 2-day a v erages. 

13SEP0 1 16:52 M:\PW\OSTWATER\REQ006\R006_Fl.LST 

All estimates e xclude commercial and b i ological water. 

-: Means zero. 

• : The sample size does not meet minimum reporting r e quirements as described in the •Third Report on Nutritlon Monitoring in the United St.ates.• 

NOTE: 757 individuals did not report body weight. They represent 6 , 314,627 individuals in the population . 

E-1 39