POLYCYCLIC AROMATIC HYDROCARBON
EXPOSURE OF CHILDREN IN LOW-INCOME FAMILIES
by
Jane C. Chuang, Patrick J. Callahan, Christopher W. Lyu,
Ying-Liang Chou, and Ronald G. Menton
Battelle Memorial Institute
Columbus, Ohio 43201-2693
Volume I: Report
Cooperative Agreement CR822073
Project Officer
Nancy K. Wilson
National Exposure Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
NATIONAL EXPOSURE RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
RESEARCH TRIANGLE PARK, NORTH CAROLINA 27711
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EPA DISCLAIMER
The information in this document has been funded wholly or in part by the United
States Environmental Protection Agency under Cooperative Agreement CR822073 with
Battelle Memorial Institute. It has been subjected to the Agency's peer and administrative
review and has been approved for publication as an EPA document. Mention of trade names
or commercial products does not constitute endorsement or recommendation for use.
BATTELLE DISCLAIMER
Battelle does not engage in research for advertising, sales promotion, or endorsement
of our clients' interests including raising investment capital or recommending investment
decisions, or other publicity purposes, or for any use in litigation.
Battelle endeavors at all times to produce work of the highest quality, consistent with
our contract commitments. However, because of the research and/or experimental nature of
this work the client undertakes the sole responsibility for the consequences of any use, misuse,
or inability to use, any information, apparatus, process or result obtained from Battelle, and
Battelle, its employees, officers, or Trustees have no legal liability for the accuracy,
adequacy, or efficacy thereof.
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FOREWORD
The mission of the National Exposure Research Laboratory (NERL) is to provide
scientific understanding, information and assessment tools that will quantify and reduce the
uncertainty in EPA's exposure and risk assessments for environmental stressors. These
stressors include chemicals, biologicals, radiation, and changes in climate, land use, and water
use. The Laboratory's primary function is to measure, characterize, and predict human and
ecological exposure to pollutants. Exposure assessments are integral elements in the risk
assessment process used to identify populations and ecological resources at risk. The EPA
relies increasingly on the results of quantitative risk assessments to support regulations,
particularly of chemicals in the environment. In addition, decisions on research priorities are
influenced increasingly by comparative risk assessment analysis. The utility of the risk-based
approach, however, depends on accurate exposure information. Thus, the mission of NERL is
to enhance the Agency's capability for evaluating exposure of both humans and ecosystems
from a holistic perspective.
The National Exposure Research Laboratory focuses on four major research areas:
predictive exposure modeling, exposure assessment, monitoring methods, and environmental
characterization. Underlying the entire research and technical support program of the NERL
is its continuing development of state-of-the-art modeling, monitoring, and quality assurance
methods to assure the conduct of defensible exposure assessments with known certainty. The
research program supports its traditional clients — Regional Offices, Regulatory Program
Offices, ORD Offices, and Research Committees -- and ORD's Core Research Program in the
areas of health risk assessment, ecological risk assessment, and risk reduction.
Human exposure to multimedia contaminants, including polycyclic aromatic
hydrocarbons, is an area of concern to EPA because of the possible mutagenicity and
carcinogenicity of these compounds. These compounds originate from industrial processes
and combustion and are present in a variety of outdoor and indoor environments. The efforts
described in this report provide an important contribution to our capability to measure and
evaluate human exposure to toxic chemicals.
Gary J. Foley
Director
National Exposure Research Laboratory
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ABSTRACT
Children in low-income families may have high exposure to polycyclic aromatic
hydrocarbons (PAH). Such exposure could arise from household locations near heavy traffic,
environmental tobacco smoke, contaminated house dust/soil, or other causes. The objectives
of this study were to establish methods for estimating total PAH exposure of low-income
children, to characterize PAH exposure among these children, and to obtain data for
determining the relative importance of the sources/pathways for PAH exposure.
The analytical methods were evaluated and validated to determine PAH in multiple
sample media (air, dust, soil, and food) and hydroxy-PAH in urine samples. A two-home
pilot study was conducted in downtown Durham, North Carolina during February, 1994.
Participants from one smoker's and one non-smoker's household with preschool children and
incomes at or below the official U.S. poverty level were recruited. Multimedia samples were
collected and analyzed for PAH or hydroxy-PAH. Nine-home winter and nine-home summer
studies were conducted in downtown Durham and the NC Piedmont area during February,
1995 and August, 1995, respectively. The 18 low-income households selected for the studies
included only non-smokers. A related four-home study was conducted in smokers' homes
during August, 1995. The collected multimedia samples from all of these studies were
analyzed for PAH or hydroxy-PAH. Descriptive statistics were determined for the combined
data from the studies. Three types of statistical analyses were also performed on natural log-
transformed data: Pearson correlation analysis, analysis of variance, and regression models.
An effective screening method was established for recruiting low-income families. A
two-day three-house field sampling protocol was established, which can be used in a large-
scale study. Indoor PAH levels were, in general, higher than outdoor PAH levels. Higher
indoor PAH levels were observed in the smokers' homes in comparison with the nonsmokers'
homes. Higher ambient PAH levels were found in inner city as opposed to rural areas. The
relative concentration trend for PAH in dust and soil was house dust > entry way dust >
pathway soil. The PAH concentrations in adults' food samples were generally higher than
those in children's food samples. However, children's potential daily doses of PAH were
higher than those of adults in the same households. Inhalation was found to be an important
pathway for children's exposure to total PAH, primarily because of the high levels of
naphthalene present in the air. Dietary ingestion and nondietary ingestion pathways were
found to be more important for children's exposure to non-volatile B2 PAH (probable human
carcinogens). The analysis of variance results suggested that inner city children had higher
total exposure to B2 PAH than did rural children.
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CONTENTS
Foreword iii
Abstract iv
List of Figures vii
List of Tables viii
List of Abbreviations x
Acknowledgment xi
1. Introduction 1
2. Conclusions . 4
3. Recommendations 7
4. Experimental Procedure 11
Selection of Households . 11
Pre-Monitoring Activities 14
Field Monitoring Activities 18
Sampling Methods 20
Analytical Methods 22
Estimates of Inhalation and Ingestion Exposure 24
Statistical Analysis 26
5. Results and Discussion 28
Recruiting of Low-Income Households . 28
Field Activities 30
Concentration Profiles of PAH in Multi-Media Samples 32
Daily Potential Dose of PAH 39
Concentration Profiles of Hydroxy-PAH in Urine Samples ......... 45
Statistical Analysis 47
Quality Control 62
References 67
Appendices
A. Household Screening Materials A-l
B. Informed Consent Form B-l
C. Participant Information Booklet C-l
D. House Observation Survey D-l
E. Pre-Monitoring Questionnaire E-l
F. Post-Monitoring Questionnaire F-l
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CONTENTS (Continued)
G. Measured PAH Concentrations in Air, Dust, Soil, and
Food Samples G-l
H. Estimated Daily PAH Exposure Levels from Inhalation,
Nondietary Ingestion and Dietary Ingestion Pathways H-l
I. Estimated Daily PAH Potential Dose Levels from Inhalation,
Nondietary Ingestion and Dietary Ingestion Pathways 1-1
J. Measured Hydroxy-PAH Levels in Urine Samples 1-1
K, Descriptive Statistics for Measured PAH Levels in Air,
Dust, Soil, and Food Samples K-l
L. Descriptive Statistics for Estimated Daily PAH Exposure
Levels from Inhalation, Nondietary Ingestion, and Dietary
Ingestion Pathways L-l
M. Descriptive Statistics for Estimated Daily Potential Dose
Levels from Inhalation, Nondietary Ingestion, and Dietary
Ingestion Pathways M-l
N. Descriptive Statistics for Measured Hydroxy PAH in
Urine Samples N-l
P. Pearson Correlation Coefficients (r) of Total Hydroxy
PAH with the Estimated Daily Potential Dose of PAH P-l
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FIGURES
Number Page
4.1 Locations of Selected Households in Four Field Studies 16
5.1 B2 PAH Concentration Profiles in Indoor and Outdoor Air 33
5.2 Estimated Fine Particle-Bound Concentrations from the
Real-Time PAH Monitor Versus Measured GC/MS
Concentrations, natural log scale 36
5.3 B2 PAH Concentration Profiles in House Dust, Entryway
Dust, and Pathway Soil 38
5.4 B2 PAH Concentration Profiles in Adult and Child
Duplicate-Diet Food Samples 40
5.5 Daily Potential Dose of B2 PAH for Adults and Children 43
5.6 Estimated Daily Potential Doses for B2 and Total PAH . 44
5.7 Hydroxy PAH Concentration Profiles in Subject's Urine Samples ..... 46
5.8 Box Plots for B2 PAH by Sample Media and by Locations 51
5.9 Box Plots for Target PAHs by Sample Media and by Locations 52
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TABLES
Number Page
4.1 A Summary of the Sampled Households 15
4.2 Field Monitoring Activities in Each Household for the
Nine-Home Summer and Four-Home Smokers Studies 19
5.1 Subject Recruitment - Methods and Results 29
5.2 Summary of Home Parameters in Four Field Studies 31
5.3 Estimated Indoor and Outdoor Fine Particle-Bound PAH
Concentrations from the PAH Monitor Average
Responses 35
5.4 Total and Fine Fraction House Dust Loading by Household 37
5.5 Summary of Daily Food Intakes From Duplicate-Diet
Food Samples 41
5.6 Summary of B2 PAH Concentrations in the Four Field
Studies by Locations 49
5.7 Summary of Total PAH Concentrations in the Four Field
Studies by Locations 50
5.8 Summary of Potential Daily Doses of B2 PAH in Adults
and Children in the Four Field Studies by Locations 53
5.9 Summary of Potential Daily Doses of Total PAH in Adults
and Children in the Four Field Studies by Locations 54
5.10 Summary of Total Target Hydroxy-PAH for Adult and Child
Subjects in the Four Field Studies by Location 55
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TABLES (Continued)
Number Page
5.11 Pearson Correlation Coefficients for B2 PAH and Total PAH
Between Different Sample Media 57
5.12 Summary of Analysis of Variance Results 58
5.13 Regression Analysis Results for Total Hydroxy-PAH Versus
Estimated B2 PAH Potential Dose 60
5.14 Regression Analysis Results for Total Hydroxy-PAH Versus
Estimated B2 PAH Potential Total Dose 60
5.15 Regression Analysis Results for Total Hydroxy-PAH Versus
Estimated Target PAH Potential Dose 61
5.16 Regression Analysis Results for Total Hydroxy-PAH Versus
Estimated Target PAH Potential Total Dose 61
5.17 Summary of Recovery Data of Spiked Perdeuterated PAH in
Multimedia Samples 63
5.18 Percent Relative Standard Deviations (% RSD) for PAH in
Duplicate Multimedia Samples . 64
5.19 Percent Relative Standard Deviations (% RSD) for
Hydroxy-PAH in Duplicate Urine Samples 65
5.20 Levels of Target PAH Found in Field Blanks . 66
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LIST OF ABBREVIATIONS
ABBREVIATIONS
NERL
—
National Exposure Research Laboratory
PAH
—
polycylic aromatic hydrocarbons
ETS
—
environmental tobacco smoke
WIC
—
Special Supplemental Food Program for Women, Infants, and
children
ANOVA
—
analysis of variance
POP
—
persistent organic pollutants
OC
—
organochlorine
OP
—
organophosphate
SES
—
socioeconomic status
ELISA
—
enzyme linked immunosorbent assay
HVS3
—
high volume small surface sampler
OMB
—
Office of Management and Budget
NC
—
North Carolina
QSIP
__
quality system and implementation plan
AFDC
—
Aid to Families with Dependent Children
DHHS
—
Department of Health and Human Service
PFT
—
perfluoro tracer
CATS
—
capillary adsorption tube sampler
MS
—
meteorological station
ASTM
—
American Society for Testing and Materials
EPA
—
Environmental Protection Agency
GC/MS
—
gas chromatography/mass spectrometry
SIM
—
selected ion monitoring
DCM
—
dichloromethane
RSD
—
relative standard deviation
EI
—
electron impact
K-D
—
Kuderna-Danish
BaP
—
benzo[a]pyrene
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ACKNOWLEDGMENT
The authors are grateful to Dr. Nancy K. Wilson of the U.S. EPA for her invaluable
advice and participation during this investigation. We also thank Dr. Robert Lewis and
Mr. Milton Bowen of the U.S. EPA as well as Ms. Frances Patterson, Ms. Shian Yen Dennis,
Mr. Wallace Lambert, and Ms. Mary Pollard of Battelle for their support in field monitoring
and sample preparation for this study. Technical assistance provided by Smith Kline Beecham
Clinical Laboratories and Brookhaven National Laboratory is also greatly appreciated.
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CHAPTER 1
INTRODUCTION
Many polycyclic aromatic hydrocarbons (PAH) present in air, dust, soil, and food are
known mutagens or animal carcinogens, and adverse health effects have been linked to
exposure to PAH (1-6). Humans can be exposed to PAH by inhaling contaminated air, by
ingesting tainted food, or by nondietary ingestion or dermal absorption from contaminated
dust or soil. The exposure resulting from ingestion of dust or soil is believed to be more
important for young children because of their play activities.
Exposure to PAH through the inhalation pathway comes from PAH present in ambient
(outdoor) and indoor air. Higher PAH concentrations have been observed in air in inner city
areas in comparison to rural areas, because of high mobile source emissions and local
stationary source emissions in the inner city (7,8). Ambient air intrusion can contribute
significantly to indoor PAH (7,9). Thus, higher inner city ambient PAH levels can contribute
to higher indoor PAH levels in inner city homes. Other significant indoor PAH contamination
can result from environmental tobacco smoke (ETS) and use of unvented heating appliances
(10-13).
Exposure to PAH through the nondietary ingestion pathway can result from PAH in
house dust or play area soil. The PAH in indoor air can be adsorbed onto the interior surfaces
of a house, such as carpets. Outside contaminated soil can be tracked into the house. The
PAH concentration profiles in house dust have shown higher levels of carcinogenic five- and
six-ring PAH compared to the noncarcinogenic two- and three-ring PAH (14,15). Higher
PAH concentrations have been found in soil from inner city areas in comparison with remote
rural areas, and in inner city road dust in areas with heavy traffic (3,16). Thus, inner city
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homes may have higher PAH in their house dust than rural homes, and this may result in
higher PAH exposure through the nondietary pathway.
Exposure to PAH through the dietary ingestion pathway is from the PAH present in the
food we consume. Food groups having significant levels of PAH include charcoal-broiled or
smoked meats, leafy vegetables, grains, fats, and oils; with typical PAH concentrations of tens
of micrograms per kilogram (i.e., tens of ppb) (17). A wide range of benzo[a]pyrene (BaP)
concentrations (0.005 to 1.17 ppb) has been reported in duplicate-diet food samples (7). This
wide concentration range may be due to the sources of food, ways of cooking, and the
analytical method used. Since an individual's typical daily food consumption is in hundreds of
grams, this wide BaP range of concentrations in food samples can result in a wide range of
daily BaP intake through the dietary ingestion pathway. It is important that the analytical
methods employed in determining PAH in food are validated and that the precision and
accuracy of the measured data are assured such that PAH exposure through the dietary
ingestion pathway can be estimated.
Children from inner city and rural areas may experience different PAH exposures
because of the differences in the nature and level of PAH contamination in these areas.
Socioeconomic status and other factors, such as location (inner city versus rural areas), are
usually adjusted for, or are not considered in field studies to assess human exposure to
environmental pollutants. These adjustments or omissions resulted in a lack of data on the
relationship between these factors, and the potential for exposure of this disadvantaged group
is usually ignored.
To provide information to remedy this situation, a three-year study was conducted.
The overall objectives of this project were to:
(1) Develop methodology for determining multimedia exposure to PAH through
multiple pathways.
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(2) Estimate the range of PAH exposure for children from low-income families by
measuring PAH in multimedia samples and measuring hydroxy-PAH in urine
samples, and
(3) Obtain data to estimate the relative importance of the contamination sources and
pathways for PAH exposures.
In the first year, we validated analytical methods to determine PAH in multiple sample
media (air, dust, soil, and food) and hydroxy-PAH in urine; conducted a two-home pilot
study; and established the study design and household selection method for the nine-home
study (18). In the second year, we selected households; conducted a nine-home field study
during the heating season (winter study); and analyzed collected multimedia samples for PAH
or hydroxy-PAH (19). In the third year, we conducted a nine-home field study during the
non-heating season (summer study); and performed statistical analysis of the data and data
interpretation. Several qualified households were identified in the winter and summer field
studies, but only nonsmokers' households were selected for these studies. Approximately half
of the identified households included smokers. To obtain PAH concentrations in multimedia
samples from smokers' homes, four smokers' households from the summer study house
screening survey were selected for a four-home field study conducted under a related PAH
field exposure study (20). The four-home smoker summer study was conducted
simultaneously with the nine-home summer study. The statistical analysis of the data herein
includes data collected in the three pilot studies performed under Cooperative Agreement
CR822073 and the data from the four smokers' households, which was collected under a
separate project under Contract 68-D4-0023 with EPA.
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CHAPTER 2
CONCLUSIONS
We have demonstrated an effective approach for conducting a screening survey to
recruit low-income families for exposure field studies. This approach includes posting study
flyers at the Special Supplement Food Program for Women, Infants, and Children (WIC)
offices, food stamp offices, social services and health departments, and asking eligible and
interested participants to call in. In general, the study consent forms, pre-monitoring
questionnaires, post-monitoring questionnaires, and participant information booklets were easy
for adult participants to understand. Adult participants had no difficulties recording child
activity diaries, adult/child food diaries, and collecting adult/child food samples. However,
the collection of children's urine samples was difficult for some participants because the
children were not used to the urine sample collectors. The participants' feedback about the
study was positive, and they expressed their willingness to participate again in a future study.
The pilot study three-day-two-house sampling protocol was condensed into a two-day-
two-house protocol for the nine-home winter study. The two-day-two-house protocol was
further modified to a two-day-three-house protocol, which was employed in the nine-home
summer and four-home smokers' summer studies. The field activities were successfully
completed on time and within budget. In conclusion, the household screening and field
sampling protocol could be modified easily for a large-scale exposure field study.
The overall method precision for polycyclic aromatic hydrocarbons (PAH)
measurements obtained from duplicate field samples was within ±9 percent for air samples,
±11 percent for dust samples, ± 13 percent for soil samples, and ± 15 percent for food
samples. The precision for hydroxy-PAH (OH-PAH) measurements in urine samples was
within ±24 percent. With few exceptions, quantitative recoveries (> 80 percent) of the
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spiked perdeuterated PAH were obtained in the multimedia samples. The recoveries of the
spiked PAH ranged from 27 ± 15 percent (fluorene-d 10) in the food samples to 113 ± 7.5
percent (chrysene-d,2) in the air samples. Recoveries of other spiked PAH were generally
greater than 80 percent. The relatively low recovery of fluorene-d I0 in the food samples is
presumably due to losses during the sample preparation steps. Only trace amounts of the
target analytes were found in the multimedia field blanks. These results demonstrated that the
various sampling and analysis methods used provide reliable and reproducible data of target
PAH.
The sum of seven B2 PAH (probable human carcinogens) ranged from 0.42 to 27.3
ng/m3 in indoor air and from 0.53 to 17.8 ng/m3 in outdoor air. Generally, PAH
concentrations in indoor air were higher than those in the corresponding outdoor air. Higher
outdoor concentrations were observed in the inner city in comparison to the rural areas. As
expected, PAH concentrations were higher in the smokers' homes than those in nonsmokers'
homes. Levels of B2 PAH ranged from 0.45 to 5.98 ppm in house dust, from 0.13 to 2.87
ppm in entryway dust, and from 0.02 to 1.77 pm in pathway soil. The B2 PAH
concentrations accounted for roughly half of the total PAH concentrations (the sum of all
target PAH) in most dust/soil samples. Levels of B2 PAH ranged from 0.04 to 2.11 ppb in
adult food samples and from 0.05 to 1.50 ppb in child food samples. With few exceptions,
the daily food intakes (kg/day) of adult subjects were higher than those of the child subjects.
The sum of target hydroxy PAH concentrations ranged from 0.105 to 4.19 ng/mL in adult
urine samples and from 0.055 to 1.86 ng/mL in child urine samples, without normalization to
creatinine levels. The hydroxy-PAH concentrations in adult's urine samples were generally
higher than those in children's urine samples.
The correlation analysis results showed positive but weak relationships for PAH among
multiple sample media (air, dust, and soil). Significant correlations were observed for PAH in
indoor and outdoor air and in outdoor air and house dust. There were no strong and direct
relationships for the PAH in duplicate-diet food samples and PAH in other sample media.
The analysis of variance (ANOVA) results showed that B2 PAH measured in inner city
homes were significantly higher than those measured in rural homes for multiple sample media
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(indoor air, outdoor air, house dust, pathway soil). Indoor air B2 PAH concentrations in
smokers' homes were also significantly higher than those in the nonsmokers' homes. There
were no statistical differences for hydroxy-PAH in both adults' and children's urine samples
between the locations (inner city versus rural areas).
The estimated total PAH daily potential dose levels suggest that inner city children had
higher B2 PAH exposures than did rural children. Inhalation was the most important pathway
for total PAH exposure for both adults and children. This resulted mainly from the high
levels of naphthalene present in air. The ingestion pathways (dietary and nondietary) became
more important than inhalation for subjects' exposure to B2 PAH. The relative importance of
children's exposure to B2 PAH was dietary ingestion > nondietary ingestion > inhalation.
The children's potential daily doses (ng/kg/day) of target PAH, including B2 PAH, were
higher than those of adults in the same household. However, there were no strong positive
relationships between the urinary PAH metabolites, hydroxy PAH, and the estimated daily
potential dose levels.
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CHAPTER 3
RECOMMENDATIONS
We recommend that a large-scale exposure study of PAH and other persistent organic
pollutants (POP) be conducted, using the methods evaluated here and in other related studies,
to investigate the effect of socioeconomic status (SES) on pre-school children's exposure to
POP at day care centers and their homes. The results of this cooperative agreement study
demonstrated that children's potential daily doses (ng/kg/day) of B2 PAH (probable human
carcinogens) were higher than those of adults in 24 low-income households. Among these
low-income families' children, inner city children appeared to have higher PAH exposure
than rural children. Both the dietary and nondietary ingestion pathways were important for
children's exposure to B2 PAH. However, inhalation may be an important pathway for
children's exposure to other persistent organic pollutants (POP) including polychlorinated
biphenyls (PCB), organochlorine (OC), and organophosphate (OP) pesticides. Children in
low-income families are thought to have higher exposure to pollutants than children in higher-
income families. These higher exposures could derive from the location of their homes and
schools, from higher dust loadings inside their homes, from environmental tobacco smoke
(ETS), and from other causes. A general outline for conducting such a study follows.
The main objective of the proposed study is to determine whether low-income children
are at greater risk due to higher POP exposure. A secondary objective is to examine the
relative importance of the exposure pathways for POP in various compound classes. The third
objective is to examine the effectiveness of utilizing less expensive screening tools for
monitoring POP exposure. The specific hypotheses to be tested are summarized below:
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Hypotheses to be Tested in Proposed Large-Scale Study
Objective
Hypothesis
Investigate impact of SES on children's
exposure to POP
Exposure to POP of low-income children
is/is not higher than those of higher-income
children
Investigate impact of sources by media on
POP exposure
Exposure from a source(s) is/is not different
in air, soil, dust, and food for different
compound classes
Investigate impact of sources in homes and
in day care centers on POP exposure
Exposure to POP at home is/is not equal to
those at day care centers
Investigate contributions of pathways to total
POP exposure
Exposure from different pathways is/is not
equal and distributions are/are not equal for
different compound classes
Investigate the association between screening
methods versus conventional methods
Exposure measured by screening methods
(ELISA and PAH monitor) does/does not
correlate well with conventional methods
Investigate the association among various
estimates of POP exposure
Exposure estimates from floor dust
measured by HVS3 do/do not correlate well
with those measured using vacuum bags.
Exposure measured by multiple
environmental media does/does not correlate
well with biological markers.
Exposures from various media do/do not
correlate with each other
The minimum sample size required for such a large-scale study was calculated based
on the results from the previous studies. Sample size calculations were conducted to
determine the minimum sample size required to statistically distinguish between B2 PAH
exposures of children in low and high income families. Sample sizes were calculated for the
first hypothesis since this is the main objective of the proposed study.
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The following assumptions were made in performing the sample size calculations:
(1) The mean B2 PAH potential dose of children living in low-income families is
approximately 34 ng/kg/day.
(2) The standard deviation of B2 PAH potential doses is approximately 24 ng/kg/day
for children living in both low and high income families.
(3) An hypothesis test should be conducted using a two-sample t-test at the five percent
significance level to determine whether average total B2 PAH exposures of children
in low and high income families are equal.
Minimum samples sizes to detect statistically significant differences between mean
B2 PAH exposures of children in low and high income families are shown in the table below.
The required sample sizes were computed for two power levels: 80 and 90 percent. The
power represents the level of confidence desired to detect a specified difference between the
two groups. An experiment designed to have 90 percent power for detecting a specified
difference will be more sensitive than one designed to have 80 percent. For each power level,
samples sizes were computed to detect a 15%, 25%, 30%, 40%, and 50% difference in
B2 PAH exposures between children in low and high income families.
To use the table, consider, for example, the number in the second row and third
column. The sample size for each study group (low income and high income families) should
be approximately 126 children if we want to have 80 percent confidence that a difference of
25% (34 versus 42.5 ng/kg/day) in B2 PAH exposures between children in low and high
income families will be detected.
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Minimal Sample Sizes Required to Detect a Difference in B2 PAH Exposures Between
Children in Low and High Income Families Based on a Two Sample t-Test Conducted at
the Five Percent Significance Level.
Power
Percent Difference Between Average B2 PAH Exposures for
Children Living in Low and High Income Families
15%
25%
30%
40%
50%
80%
350
126
88
50
32
90%
470
170
120
66
43
Calculated sample sizes assume that the standard deviation in B2 PAH exposures is approximately
0.024 jig/kg/day for both groups and that the average B2 PAH exposure for children in low-income families is
0.034 /ig/kg/day.
The large-scale POP exposure study could be conducted over a period of three years.
In year one, we would establish the study design, prepare questionnaires, consent forms and
protocols, obtain the required approvals from the Office of Management and Budget (OMB),
the Human Subjects Committee at Battelle, and U.S. EPA. In the second year, the field
sampling and analysis activities would be performed and continued through the first quarter of
the third year. Data analysis would be conducted in the remainder of the third year.
The overall technical approach would be as follows:
• Establish a study design
• Establish questionnaires, consent forms, and protocols
• Obtain required approval from Office of Management and Budget (OMB) and from
Human Subjects Committee at Battelle and U.S. EPA
• Recruit eligible day care centers and households
• Conduct field sampling
• Analyze collected multi-media samples
• Conduct data analysis
• Prepare final report
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CHAPTER 4
EXPERIMENTAL PROCEDURE
The two-home pilot study was conducted in Durham, North Carolina (NC), during
February, 1994. One smoker's and one non-smoker's home were sampled. The nine-home
winter and summer studies were conducted in Durham, NC and in the NC Piedmont area
during February, 1995 and August, 1995, respectively. Only non-smokers' households were
involved in these studies. A four-home study of smokers' households was conducted
simultaneously with the nine-home summer study, under a separate project. Multi-media
samples were collected from 24 low-income homes in these field studies. Since these studies
involved the use of human subjects, prior approvals were obtained from Human Subjects
Committees at Battelle and the U.S. EPA before field activities began. Prior to the two-home
pilot study, a Quality System and Implementation Plan (QSIP) was submitted to the U.S. EPA
and approval was obtained.
This section summarizes the procedures used for selecting households; the study
consent forms, the questionnaires, and child activity diaries that were administered; the
sampling procedures used to collect air, dust, soil, food and urine samples; the analytical
methods used; and the statistical analysis method employed.
SELECTION OF HOUSEHOLDS
The following selection criteria were used to develop the household screening
questionnaire.
• At least one child aged two-five lives in the household
11
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• The child must stay home with an adult during the day
• The child must be toilet-trained
• The family is not planning to move before the designated sampling date
• They are receiving public assistance such as food stamps, the Aid to Families with
Dependent Children (AFDC), the Special Supplemental Food Program for Women,
Infants, and Children (WIC), meeting the Department of Health and Human Service
(DHHS) poverty guidelines, etc.
• Inner city homes must be located near heavy traffic
• Rural homes must be located away from heavy traffic
• If there is a smokeT in the household, he or she must smoke more than 10 cigarettes
per day inside the house.
For the two-home pilot study, a field survey/door-to-door screening approach was used
to identify and recruit eligible study households. This door-to-door screening for eligible
households was conducted in low-income neighborhoods. One smoker's and one nonsmoker's
households in Durham, North Carolina were selected. In the nine-home winter study, five
different household selection approaches were used to recruit the households. The approaches
are summarized as follows:
(1) City/Major Streets/Telephone Screening
(2) City/Census Data Tract 14/ Telephone Screening
(3) Rural/Mail Survey
(4) Rural/Telephone Screening
(5) City and Rural Areas/Flyers and Posters/Call-in
A brief description of each approach is as follows:
Approach (1): City/Major Streets/Telephone Screening
a. Identify Major Heavy Traffic Streets in the City of Durham.
12
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b. Use Crisscross Telephone Directory to collect phone numbers of households
living in the selected areas (along the major heavy traffic streets).
c. Conduct telephone screening.
Approach (2): City/Census Data Tract 14/Telephone Screening
a. Use 1990 census data to identify poor neighborhoods in the City of Durham
(tract 14 has the highest number in Durham).
b. Use National Telephone Directory to collect phone numbers of households
living in the selected areas (tract 14).
c. Conduct telephone screening.
Approach (3): Rural/Mail Survey
a. Use 1990 census data to identify poor neighborhoods in the rural area of
Durham county.
b. Conduct field survey to select appropriate neighborhoods.
c. Deliver mail survey to each selected household.
Approach (4): Rural/Telephone Screening
a. Use National Telephone Directory to collect phone numbers of households
living in the selected areas.
b. Conduct telephone screening.
Approach (5): City & Rural Areas/Flyers & Posters/Call-in
a. Target the households with young children.
b. Obtain the approval from the county WIC offices, food stamp offices, and
the county social services department, and health department to place study
flyers and posters in their offices. (The Durham county social services
department even included a letter in their monthly payment to their clients to
encourage them to call the Battelle survey study director).
c. Place study flyers and posters in the WIC offices, food stamp offices, the
county social services department, and county health department (a copy of
the flyer is attached).
13
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d. Respond to the call-ins and conduct the screening interviews.
We found that the most cost-effective way to obtain qualified households was to target
low-income families with young children. This method (approach 5) was used to recruit 22
households and eight backup households for the nine-home winter, nine-home summer, and
the related four-home smoker studies. The household screening materials used (in approach 5)
are given in Appendix A. A summary of all the households from the four field studies is
presented in Table 4.1. Locations of the study households in these field studies are illustrated
in Figure 4.1.
PRE-MONITORING ACTIVITIES
The study consent form was simplified after the two-home pilot study. The simplified
final version of the study consent form was used in the nine-home winter, nine-home summer,
and four-home smoker studies (Appendix B). It provides information on study activities and
about participants' rights. After the screening, we called each eligible household and read the
consent form to the adult subject. The adult subjects were asked to discuss the study activities
with the other household adult members. A confirmation call was made the next day to each
adult subject. Once the subject agreed to participate in the study, an appointment was made
with the subject to sign the consent form. The signed consent form was obtained from each
subject during our initial visit to each selected household. Typically, this initial visit was
scheduled approximately one month before the designated field monitoring date. During this
visit, the interview staff explained the consent form to the subject once again and answered
any questions that the subject asked about the study. A new carpet doormat (30 in x 18 in)
was then placed at the main entrance of each household. At the conclusion of the visit, a
copy of the consent form and a study appointment calendar were left with the subject.
The Participant Information Booklets (Appendix C) were used for all these four field
studies. An activities check list was placed on the back of the cover sheet to remind the
participant of all the study activities that he/she would be doing during the 24-hour sampling
14
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TABLE 4.1. A SUMMARY OF THE SAMPLED HOUSEHOLDS
Household
Code(a)
Field Study
Location
Smokers/N onsmoker
Occupants
PNA
two-home pilot
inner city - Durham
nonsmoker
PSB
two-home pilot
inner city - Durham
smoker
WNA
nine-home winter
rural area - Apex
nonsmoker
WNB
nine-home winter
rural area - Holly Springs
nonsmoker
WNC
nine-home winter
rural area - Zebulon
nonsmoker
WND
nine-home winter
rural area - Zebulon
nonsmoker
WNE
nine-home winter
inner city - Durham
nonsmoker
WNF
nine-home winter
inner city - Durham
nonsmoker
WNG
nine-home winter
inner city - Durham
nonsmoker
WNH
nine-home winter
inner city - Durham
nonsmoker
WN1
nine-home winter
inner city - Durham
nonsmoker
SNA
nine-home summer
inner city - Durham
nonsmoker
SNB
nine-home summer
inner city - Durham
nonsmoker
SNC
nine-home summer
inner city - Durham
nonsmoker
SND
nine-home summer
inner city - Durham
nonsmoker
SNE
nine-home summer
inner city - Durham
nonsmoker
SSF
four-home smoker
inner city - Durham
smoker
SSG
four-home smoker
inner city - Durham
smoker
SNH
nine-home summer
rural area - Rougemount
nonsmoker
SNI
nine-home summer
rural area - Zebulon
nonsmoker
SNJ
nine-home summer
rural area - Zebulon
nonsmoker
SSK
four-home smoker
rural area - Zebulon
smoker
SNL
nine-home summer
rural area - Apex
nonsmoker
SSM
four-home smoker
rural area - Holly Springs
smoker
00 The first letter denotes study code: P = pilot study, W = winter study, and S = summer
study; the second letter denotes smoking code: N = nonsmoker and S = smoker; and the
third letter denotes household ID.
15
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N
On
RURAL
SNH
O.xfofcdP^Hend e rso n
Roudemont
INNER CITY
WNE, WNF, WNG, WNH, WNI,
SNA, SNB, SNC, SND, SNE,
SSF, SSG, PNA, and PSB
m
501
Hillsborough
RURAL
SNI, SNJ, SSK,
WNC, and WND
Durham
^f§8
Qhafeel Hill
^751
Raleigh
RURAL
WNA and SNL
prings
RURAL
WNB and SSM
10 mi
Figure 4.1. Locations of Selected Households in Four Field Studies
-------
period. The following is a brief description of each form included in the Participant
Information Booklet.
¦ Child Activity Diary
There are two pages in the Child Activity Diary. The first page is an activities
schedule for the adult participant to record the child's indoor and outdoor
activities and time. The second page lists indoor and outdoor activities for the
adult to check "YES" or "NO" for each activity. Also listed on page 2 are
questions about time spent in doing the indoor and outdoor activities, which
could be answered by using the information recorded on page 1 of the diary.
¦ Adult/Child Food Diary and Food Sample Collection
There are four categories in the food diary: Breakfast, Lunch, Dinner, and
Snacks. Subjects were only required to record the foods (including water) they
ate or drank during the 24-hour sampling period. The second plate method was
used for the food collection. The adult subjects were instructed by the
interviewer about how to collect the food samples during the pre-monitoring
interview.
¦ Instructions for Urine Sample Collection
To simplify the urine sample collection procedure, we did not ask the subject to
record the sample collection time. The instructions list the date and time periods
for each sample. A bold, large number (1 through 4) was printed on each
container label. The subject was instructed to pick the container by number
(from 1 to 4). We provided each household with two urine collectors,one for the
adult and one for the child. The urine collector (Scientific Products) is a plastic
container which fits securely under any toilet seat and has a pour spout for easy
transfer of the urine specimen to a plastic sample bottle for storage.
The house observation survey used in these field studies is given in Appendix D. The
information collected for the interior of the house was the house floor plan. The house
exterior information included characteristics of the house and a sketch of the house location
and surrounding area. In the two-home pilot study, the house observation survey was
conducted during the Day-1 sampling period. For the nine-home winter, nine-home summer,
and four-home smokers studies, the house observation survey was conducted during a
reminder visit to each household (about one week before the designated sampling date).
17
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During this visit, we also deployed the perfluoro tracer (PFT) source tubes used to measure
air exchange rate in each household and paid the participant $15 to cover the cost of
purchasing extra food to be prepared and collected in the study. The remaining $60 was paid
to each participant after the field monitoring effort was complete.
FIELD MONITORING ACTIVITIES
The two-home pilot study was conducted in February 1994 and the field sampling
activities were complete during a three-day period (18). The nine-home winter study was
carried out in February 1995. A two-day-two-house study protocol was established based on
the two-home pilot study (19). The nine-home summer study was performed simultaneously
with the four-home smokers study in August 1995. A two-day-three-house study protocol was
established based on the nine-home winter study. A total of 13 households were sampled
using a two-day-three-house study protocol. The two-day-thrce-house field monitoring
activities are summarized in Table 4.2. On the first sampling day, the study team visited two
households in the morning and one household in the afternoon. Day-1 activities included
setting up the meteorological station, installing indoor/outdoor monitors, deploying sampling
tubes, conducting pre-monitoring interview, and instructing the participant on foods and urine
sample collection and child activity and food diaries. On the second sampling day, the study
team visited one household in the morning, one around 12 noon, and one in the afternoon.
Day-2 activities included removing the meteorological station, if necessary, unloading air
samplers and indoor/outdoor monitors, removing capillary adsorption tube sampler (CATS)
and PFT source tubes, conducting post-monitoring interview, examining foods and urine
samples and child activity and food diaries, collecting dust and soil samples, paying the
participant $60, and presenting a certificate of appreciation to the participant.
The pre-monitoring questionnaire and the post-monitoring questionnaire used in these
studies are presented in Appendix E and F respectively. The pre-monitoring questionnaire
contains the following information: the characteristics of the house, household information,
child activity information, and food consumption information of the child and the adult. The
post-monitoring questionnaire contains the information about the child's and adult's activities
18
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TABLE 4.2. FIELD MONITORING ACTIVITIES IN EACH HOUSEHOLD FOR THE
NINE-HOME SUMMER AND FOUR-HOME SMOKERS STUDIES
Monitoring
Day Activity
1 (a) Installed one Meteorological Station (MS), one indoor sampler, one
outdoor sampler, one PAH monitor indoors, and one PAH monitor
outdoors at each of three houses.
(b) Installed CATS sampling tubes and turned on the indoor and outdoor
samplers.
(c) Conducted pre-monitoring interviews with the adult subjects.
(d) Provided Participant Information Booklet to the participant and give
instructions and containers on food and urine sampling to the participant.
2 (a) Unloaded air samples, and turned off the PAH monitors at all three
houses.
(b) Removed indoor samplers, outdoor samplers, PAH monitors, and MS
from the households.
(c) Removed PFT source tubes and sampling tubes and placed them in
separate packages.
(d) Conducted house dust, entryway dust and pathway soil sampling.
(e) Conducted post-monitoring interviews with the participants and picked up
food and urine samples, as well as the Participant Information Booklet.
(f) Presented a certificate to each participant and paid $60 to the participant.
19
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during the 24-hour sampling period and the participant's feedback about the study. A Field
Data Log Book was also used for each household to record critical information during the
sampling period, and pictures were taken to document the progress of the study.
SAMPLING METHODS
Indoor and outdoor air were sampled simultaneously during a 24-hour period at each
household. A 20 L/min sampler equipped with a quartz fiber filter (47 mm I.D.) and XAD-2
cartridge (-30 g) was used indoors and outdoors (21). The sampler operated at
approximately 20 L/min. The initial flow rate of each sampler was checked and recorded.
After sampling, the filter and XAD-2 samples were wrapped in clean aluminum foil, placed in
a clean container, and stored in a freezer at Battelle, Durham Office. The final flow rate of
each sampler was checked and recorded before the sampler was removed.
The house dust samples were collected using the High Volume Small Surface Sampler
(HVS3) in designated areas on the carpet where the child's highest play activity occurs. The
HVS3 unit was operated following an American Society for Testing and Materials (ASTM)
standard method (22-23). The dust samples were collected and transferred to clean
pre-weighed and labeled jars, stored in a freezer at Battelle, Durham Office.
The entryway dust samples were collected at the primary entrance to the house. The
samples were obtained by turning over the entryway doormat, which had been placed 30 days
earlier, and shaking it to loosen the embedded particles. The loosened particles were collected
onto a piece of cleaned aluminum foil and then transferred to a clean pre-weighed jar, stored
in a freezer at Battelle, Durham Office.
The walkway soil samples were collected from a location that represents a primary
walkway in the home. According to procedures used in the previous EPA study (14), the
walkway soil was scraped from the top 0.5-cm of soil. A minimum area of 0.093 m2 (1 ft2)
was scraped with a stainless steel spatula, and the soil was placed in a clean jar. The sample
jar was sealed with Teflon tape, stored in a freezer at Battelle, Durham Office.
20
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Food samples were accumulated for each meal on the sampling day. Food samples
were collected from the in-home meals eaten by the subjects. Samples of the beverages
consumed were also collected. The participants were asked to prepare duplicate portions of
the subjects' meals for analysis. A detailed protocol for collecting food samples was prepared
in the Participant Information Booklet and provided to the participants. The food samples
were stored in labeled plastic containers and placed in a cooler at each household, then in a
freezer at Battelle, Durham Office.
The urine samples from the subjects were collected at the designated times following
the approved protocols described in the Participant Information Booklet. We asked the
participants to collect the urine samples by using labeled plastic containers. A standard
protocol was provided to the participants. Four grab urine samples were collected from each
subject: (1) the first void in the morning, (2) two-three hours after breakfast, (3) two-three
hours after lunch, and (4) two-three hours after dinner or before going to bed. The collected
urine samples were placed in a cooler (< 4°C) at each household and then transported back to
Battelle, Durham Office and placed in a freezer. Note that the urine samples from each
subject were transported separately back to Battelle Columbus Laboratory and were combined
in the laboratory prior to sample preparations.
In addition to the field samples, one field blank in each sample medium was collected
as a quality control sample. The field blank for air sample was a filter/XAD-2 cartridge that
processed through field handling and shipping together with the field samples, but without
sampling air. The field blanks for dust/soil, food and urine samples were the empty
containers that were used for the respective samples, processed through field handling and
shipping.
The collected multimedia samples from two to three homes were grouped together and
transported back to Battelle Columbus Laboratory for analysis. The samples were packed
with dry ice in coolers and sent back by Federal Express overnight delivery. Chain-of-
custody forms were signed; dated; packed with the samples and sent back to the laboratory.
The sample handling and shipping protocol detailed in the QSIP was followed.
21
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Real-time PAH monitors (Model PAS 1002i) obtained from EcoChem Technologies,
Inc. (West Hills, CA) were employed in each house indoors and outdoors during the 24-h
sampling period. The PAH monitors are based on the principle of photoelectric ionization of
PAH adsorbed on the surface of aerosol particles. A test of the response of the PAH monitor
was carried out prior to field monitoring by igniting a kitchen match held approximately
30 cm from the monitor's inlet. The response of the PAH monitor to this test indicated that
the monitor is operating pTopeTly.
ANALYTICAL METHODS
The filter/XAD-2 samples and field blanks were spiked with known amounts of
fluorene-d10, pyrene-d10, chrysene-d12, benzo[k]fluoranthene-d12, perylene-d12, and extracted
with dichloromethane (DCM) by the Soxhlet technique. The DCM extract was concentrated
by Kuderna Danish (K-D) evaporation and analyzed by gas chromatography/mass
spectrometry (GC/MS) operated in the electron impact (EI), selected ion monitoring mode
(SIM) for target PAH (8,13).
The house dust samples were separated into coarse and fine (< 150 /xm) fractions and
only the fine fractions of the dust samples were subjected to subsequent analysis. An aliquot
of each dust and soil sample was spiked with known amounts of perdeuterated PAH and
extracted twice each with 10 mL of hexane in a sonication bath for 30 minutes. The hexane
extracts were combined, filtered, and concentrated to 1 mL for PAH analysis (14).
The collected solid and liquid food samples from each subject were combined and
homogenized. An aliquot of the homogenized food sample was spiked with known amounts of
perdeuterated PAH, and refluxed with 39 percent KOH in ethanol for 1 hour. The mixture
was then extracted with hexane and washed with 4 percent KOH solution, 10 percent HC1
solution, and distilled water, and then fractionated by a 10 gram silica gel column. The
hexane/DCM fraction was concentrated for PAH analysis (18).
The urine samples from each subject were combined into one sample. An aliquot of
each composite sample was sent to Smith Kline Beecham Clinical Laboratories for the
22
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determination of creatinine. Another aliquot of each composite sample was refluxed with 6N
HC1 and DCM for 1 hour and extracted with DCM. The DCM extract was methylated by
diazomethane and fractionated by a silica gel column (18). The target hexane/DCM fraction
containing methoxy-PAH were analyzed by EI GC/MS for methoxy-PAH.
The sample extracts and standard solutions were analyzed by 70 eV electron impact
gas chromatography/mass spectrometry. A Finnigan TSQ-45 GC/MS/MS instrument,
operated in the GC/MS mode was used. Data acquisition and processing were performed with
an INCOS 2300 data system. The GC column was a DB-5 fused silica capillary column
(30m x 0.25 mm; 0.25 m film thickness), and the column outlet was located in the MS ion
source. Helium was used as the GC carrier gas. Following injection, the GC was held at
70 °C for two minutes and the column was temperature-programmed to 290 °C at 8 °C/min.
The MS was operated in the selected ion monitoring (SIM) mode. Peaks monitored were the
molecular ion peaks and their associated characteristic fragment ion peaks. Identification of
the target analytes was based on their GC retention times relative to those of corresponding
internal standards. Quantification of target analytes was based on comparisons of the
respective integrated ion current responses of the target ions to those of the corresponding
internal standards using average response factors of the target analytes generated from
standard calibrations (18).
The estimated detection limits for PAH and hydroxy-PAH were 1 ng and 0.5 ng per
sample, respectively. These values were estimated according to the analytes' signal to noise
ratios from the lowest levels of standard calibrations.
The estimated detection limits expressed in units corresponding to each sample medium
were described as follows:
Sample Media Estimated Detection Limit
Air 0.03 ng/m3 (30 m3 of air sample volume)
Dust/Soil 1 ng/g (ppb) (1 g of dust/soil analyzed)
Food 0.02 ng/g (ppb) (50 g of food analyzed)
Urine 0.017 ng/mL (jttg/L) (30 mL of urine analyzed).
23
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ESTIMATES OF INHALATION AND INGESTION EXPOSURE
The estimates of PAH exposure through inhalation were based on the time-weighted
concentration, using indoor and outdoor PAH levels, and the amount of time the subject spent
indoors and outdoors. The maximum exposure estimates from inhalation pathway was based
on the following equation;
where
c * t + c * t
j = i £ £ * v
inh t + t
Einh = estimates of daily PAH exposure through inhalation, ng/day
Cj = indoor PAH concentration, ng/m3
C0 = outdoor PAH concentration, ng/m3
tj = subject's time spent indoors, min
t0 = subject's time spent outdoors, min
V = the estimated subject's ventilation rate, 20 or 15 m3/day.
The maximum PAH exposure estimates from nondietary ingestion pathway were based
on 1IVS3 carpet dust and pathway soil PAH levels and the amount of time spent indoors and
outdoors. The equation is described as follows:
t, * D. + t * F
E , = —i ± 2 2 * Mx 1000
n-ing t. + t
i o
where
En.ing = estimates of daily PAH exposure through nondietary ingestion, ng/day
Dj = PAH concentration in the carpet dust, /*g/g
P0 = PAH concentration in the walkway soil, figfg
24
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ti
to
M
subject's time spent indoors, min
subject's time spent outdoors, min
subject's estimated daily dust/soil intake, 0.06 or 0.1 g.
The maximum exposure estimates from dietary ingestion pathway were based on the
PAH levels in the duplicate diet food samples and the amounts of the food consumed. The
following equation is used for the calculation:
E, . = C. * M* 1000
f-iag t f
where
Ef-ing = estimates of daily PAH exposure through dietary ingestion, ng/day
Cf = PAH concentration in the daily food samples, /Kg/kg
Mf = the daily mass of food intake, kg/day
The exposure values for inhalation and ingestion (dietary and nondietary) can be
converted to units of potential dose by assuming 100 percent absorption in the lung and
stomach. Various factors can be found in the literature to account for physical, chemical,
and/or physiological processes. For maximum estimates, this conversion gives upper limits
on PAH available for delivery to target organs (lung or stomach):
Inhalation dose = Einh/Wt, ng/kg/day
Nondietary ingestion dose = En.ing/Wt, ng/kg/day
Dietary ingestion dose = Ef.ing/Wt, ng/kg/day
where
Einh = the estimate of inhalation exposure, ng/day
En.1[tg = the estimate of nondietary exposure, ng/day
Ef.ing = the estimate of dietary exposure, ng/day
Wt = the estimate body weight of the subject, kg
25
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following assumptions (24,25) were made for the above calculation:
Average adult subject ventilation rate: 20 m3/day
Average child subject ventilation rate: 15 m3/day
Adult subject daily house dust intake: 0.06 g
Child subject daily house dust intake: 0.1 g
Adult subject's body weight: 71.8 kg
Child subject's body weight: 17.4 kg
STATISTICAL ANALYSIS
Statistical analyses were conducted on the following types of samples collected in the
four field studies:
¦ 24-hr integrated indoor and outdoor air samples
¦ House dust samples collected by HVS3
¦ Pathway soil samples
¦ 24-hr duplicate diet food samples
¦ Composite grab urine samples.
Descriptive statistics (sample size, mean, standard deviation, minimum, and maximum) were
determined for each of the above sample types. Three additional types of statistical analyses
were performed: Pearson correlation analyses, analysis of variance (ANOVA), and regression
models. While descriptive statistics were performed on the raw data, the correlation analyses,
and ANOVA, and regression analytes were carried out on natural log-transformed data. For
PAH concentrations less than the detection limit, half of the detection limit was used.
Descriptive statistics were generated for measured PAH data by compound, sample
medium, field study, and location. Similar descriptive statistics were obtained for measured
hydroxy-PAH data by compound, by field study, and location. In addition, descriptive
The
26
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statistics were generated on the calculated data of estimated daily exposure and dose by
compound, field study, and exposure pathway.
Pearson correlation coefficients were calculated on the combined data from the four
field studies to examine the relationships between PAH concentrations for different sample
media and the relationship of hydroxy PAH concentration with B2 PAH dose level and target
PAH dose level for each exposure pathway.
The ANOVA models were used to examine the effects of location (inner city versus
rural areas), study, and presence of ETS on B2 PAH, total PAH and total hydroxy PAH
concentrations for each sampled medium. The ANOVA analysis was conducted on the
combined data from the four field studies. Total PAH and total hydroxy PAII were computed
as the sum of the measured concentrations of all target PAH and all target hydroxy PAH,
respectively. B2 PAII was computed as the sum of the concentrations of the target PAH that
are classified as B2 (probable human carcinogens) by the U.S. EPA's Integrated Risk
Information System. Hydroxy PAH data were expressed in two units: ng of hydroxy PAH
per mL of a urine sample (ng/mL) and /xmole of hydroxy PAH per mole of creatinine in the
urine sample (^mole/mole). The ANOVA models were fitted to both the ng/ml and
/xmole/mole total hydroxy PAH data.
Regression models were employed to examine the relationships between hydroxy PAH
and estimated daily PAH dose levels. For each measurement unit (ng/mL and /^mole/mole),
two different types of regression models were fitted to the hydroxy PAH data. The first type
of model included factors for geographical location (inner city versus rural areas) and
estimated daily PAH dose from inhalation, nondietary ingestion (dust and soil) and dietary
ingestion. The second type of model included factors for geographical location and total
estimated daily PAH dose. The total estimated daily PAH dose was computed as the sum of
the estimated daily PAH doses from inhalation, nondietary ingestion and dietary ingestion.
Separate models were fitted to the hydroxy PAH data for adults and children. In addition,
models were fitted using both B2 PAH and total PAH as the estimated daily PAH dose
factors.
27
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CHAPTER 5
RESULTS AND DISCUSSION
RECRUITING OF LOW-INCOME HOUSEHOLDS
A number of different methods were employed to recruit low-income families. The
results are summarized in Table 5.1. Note that the Approach 5 used in the nine-home winter
study was the most effective way to recruit low-income families. This approach targeted low-
income households with young children. We obtained the approval from the local county
Special Supplemental Food Program for Women, Infants, and Children (WIC) offices, food
stamp offices, county social services department, and health department to post study flyers
and posters in their offices. The county social services department even included a letter to
their clients in the monthly welfare payment to encourage them to call us. We accepted
collect calls from the respondents and conducted telephone screening interviews with the
subjects when they called in. Since a large portion of our study subjects did not have a
telephone at home, this approach allowed us to reach this group; they could use a public phone
and call us collect. Eighty-five (85) households responded to our study flyers and posters.
Among the eighty-five households that responded (representing 54% of the calls), forty-six
households met all the eligibility criteria. During the nine-home summer study, we used the
same approach to recruit the study subjects. In addition to posting study flyers in the local
social services agencies, we also asked eligible and interested study subjects to tell their
friends and relatives about the study. Two of the eligible study subjects were recruited
through referrals. We used the same recruiting method for the four-home smoker study and
obtained similar effective results. These results confirmed that this subject recruiting method
28
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TABLE 5.1. SUBJECT RECRUITMENT - METHODS AND RESULTS
Study
Methods
Results
Pilot Study
Field Survey/Door-to-Door Screening
631 households were contacted; 34 percent
response rate; none of the responded
households met all the eligibility criteria.
Nine-Home
Winter Study
1)
Heavy Traffic Locations/Telephone
Screening
459 households were called; 33 percent
response rate; none of the responded
households met all the eligibility criteria.
2)
Census Data/Low-Income
Neighborhoods/Telephone Screening
423 households were called; 25 percent
response rate; only one of the responded
households met all the eligibility criteria.
3)
Census Data/Low-Income
Neighborhoods/Field Survey - Rural
area
60 households were contacted; 10 percent
response rate; only one of the responded
households met all the eligibility criteria.
4)
Rural areas/Telephone Screening
466 households were called; 15 percent
response rate; only one of the responded
households met all the eligibility criteria.
5)
Placed study posters/flyers in the local
social services offices, WIC clinics, and
health departments
85 households responded to the
poslcrs/flycrs; 46 households met all the
eligibility criteria.
Nine-Home
Summer Study
Placed study posters/flyers in the local
social services offices, W1C clinics, and
health departments; also asked eligible and
interested participants to refer their friends
and relatives to us
Recruited nine city households (four were
backups) and six rural households (two
were backups).
Four-Home
Smoker Summer
Study
Same as Nine-Home Summer Study
Recruited four city households (two were
backups) and four rural households (two
were backups).
29
-------
(Approach 5) is effective for recruiting low- income families with young children. This
recruiting method can be modified for a larger scale study targeted at low-income families.
FIELD ACTIVITIES
The two-home pilot study three-day-two-house sampling protocol was modified into a
two-day-two-house sampling protocol and used in the nine-home winter study. A
two-day-three-house sampling protocol was then used in the nine-home summer and four-home
smoker studies. We demonstrated that the two-day-three-house protocol worked well in these
studies because of our experience in the previous studies, established sampling protocols, and
well trained field team members. This sampling protocol could be modified to study more
than three households with more field team members, and could serve as a model for future
similar large-scale exposure field studies.
In general, the field activities were successfully conducted for the four field studies.
The study consent forms, pre-monitoring questionnaires, post-monitoring questionnaires and
participant information booklets were easy for adult subjects to understand. Adult subjects
had no difficulties recording child activity diaries, adult/child diaries, and collecting
adult/child food samples. However, child urine collection was a difficult part of the study
activities for some adults. A few adults reported that it was difficult to collect child urine
samples through the urine collection bonnets, because their children were not used to the urine
collectors. This problem may be minimized by training the children to use bonnets prior to
urine collection. The participants responded that overall study activities did not burden or
bother them. They expressed their willingness to participate again in a similar, future study
even if the incentive payment were reduced from $75 to $50.
The heating/cooking system in each study home was noted during the pre-monitoring
survey. The house volume was also measured during the household observation survey. The
house air exchange rates were measured by the decay rates of perfluoro tTacer (PFT).
Table 5.2 summarizes these house parameters including heating/cooking system, house
volume, and air exchange rate. The heating systems of the 24 houses include central electric
30
-------
TABLE 5.2. SUMMARY OF HOME PARAMETERS IN FOUR FIELD STUDIES
Household
Code(a)
Heating System
Cooking
System
House
Volume, ft3
B^^B^ssassaaBsaaoe
Overall Air
Exchange Rate, tr1
PNA
central gas heating
electric
5,069
1.2132 ± 0.193
PSB
central gas heating
electric
6,428
0.551 ± 0.076
WNA
central electric heating
electric
7,587
0.358 ± 0.048
WNB
electric, kerosene heater
electric
3,172
1.396 ± 0.163
WNC
electric, kerosene heater
electric
11,637
0.682 ± 0.081
WND
central electric heating
electric
7,046
0.496 ± 0.068
WNE
wood stove, kerosene heater
electric
9,828
1.082 ± 0.147
WNF
open-flame gas heater
electric
5,487
1.195 ± 0.360
WNG
central gas heating
electric
5,626
1.549 ± 0.191
WNH
gas-base-board heating
electric
11,280
1.415 ± 0.226
WNI
central gas heating
electric
12,985
1.897 ± 0.346
SNA
fireplace, portable heater
electric
9,828
2.389 ± 1.168
SNB
central electric heating
electric
6,991
1.146 ± 0.317
SNC
central gas heating
electric
9,816
3.227 ± 2.099
SND
central gas heating
electric
10,667
0.404 ± 0.064
SNE
central gas heating
electric
10,193
0.564 ± 0.063
SSF
central gas heating
electric
12,144
1.616 ± 0.185
SSG
central gas heating
gas
8,035
0.654 ± 0.167
SNH
central gas heating
electric
9,476
0.481 ± 0.054
SNI
central electric heating
electric
11,637
0.719 ± 0.087
SNJ
fireplace, electric
electric
9,955
0.313 ± 0.038
SSK
fireplace with fan
electric
9,718
0.515 ± 0.058
SNL
central electric heating
electric
7,587
0.257 ± 0.036
SSM
kerosene heater, fireplace
electric
5,362
0.937 ± 0.124
(a) The first letter denotes study code: P = pilot study, W = winter study, and S = summer
study; the second letter denotes smoking code: N = nonsmoker and S - smoker; and the
third letter denotes household ID.
31
-------
and gas heating, kerosene heaters, open-flame gas heater, and fireplaces. Most of the houses
had electric cooking appliances and only one house had gas cooking appliance. The overall
air exchange rates of the houses ranged from 0.257 + 0.036 to 3.227 ± 3.099 h"1.
CONCENTRATION PROFILES OF PAH IN MULTI-MEDIA SAMPLES
The PAH concentrations in multimedia samples (air, dust, soil, and food) from the four
field studies are summarized in Table G-l through G-4 in Appendix G. These tables show
concentrations for individual target PAH and for the sum of all target PAH. Also reported is
the sum of B2 PAH (probable human carcinogen). For ease of discussion in this section, the
sum of target PAH and the sum of B2 PAH are referred as total PAH and B2 PAH, respec-
tively. The data reported in these tables were corrected for the corresponding field blanks.
The PAH concentration profiles in air in these four field studies are in agreement with
those from the previous studies (8,9,13) showing that with few exceptions, the PAH
concentrations decrease as the ring sizes of PAH increase. The most abundant target PAH
found in air was naphthalene and the least abundant PAH was, in general,
dibenz[a,h]anthracene. Levels of PAH in indoor air in most houses were higher than in the
corresponding outdoor air. Figure 5.1 shows B2 PAH concentration profiles in indoor and
outdoor air in the four field studies. As expected, higher indoor B2 PAH concentrations were
observed in the smokers' homes as opposed to nonsmokers' homes. Among the nonsmokers'
homes, higher average B2 PAH concentrations in indoor air were observed from the winter
study in comparison with those from the summer study. This temporal variation was partly
from the use of heating appliances in the winter. Ambient B2 PAH concentrations in the
winter heating season were also higher than those in the summer non-heating season. Note
that outdoor B2 PAH levels were higher than indoor levels in the two-home pilot study. The
two households monitored were located close to each other in downtown Durham. The high
ambient B2 PAH level may have resulted from heavy traffic and possible local contamination
sources.
The real-time PAH monitors were also employed in these field studies, both indoors
and outdoors, during the corresponding 24-hr sampling period. The average PAH monitor
32
-------
u>
u>
m
e
G
_o
*•4—»
C3
1—
a
-------
response in pA for each household was converted to an average PAH concentration in ng/m3
by using the conversion factor of 1000 ng/m3/pA established by previous studies (26,27). The
results are summarized in Table 5.3. Note that the PAH monitor responds to fine particle-
bound PAH (< 1-2 /xm), and the measured PAH values from integrated sampling include both
vapor and particle-bound PAH. As shown in Table 5.2, the estimated indoor fine particle-
bound PAH levels derived from the PAH monitor's responses were generally higher than the
corresponding outdoor levels. These relative concentration trends were also observed for
measured B2 PAH (mostly particle-bound) from 24-hr integrated air sampling. Figure 5.2
displays the relationships between the estimated PAH concentrations derived from the PAH
monitor's responses and the measured B2 PAH concentrations of the 24-hr integrated
sampling in natural log scale. A direct and positive relationship between these two types of
measurements was observed with Pearson correlation coefficient (r) of 0.71. This finding
suggests that the real-time PAH monitor can be used as a field screening tool for monitoring
B2 PAH in future large-scale studies.
The house dust loadings of all the 24 homes in the four field studies are summarized in
Table 5.4. Levels of house dust ranged from 0.311 to 691 g/m2 for total dust loadings and
from 0.193 to 392 for fine dust (< 150 jim) loadings. The highest house dust loading was
observed in household SSF. This was a smoker's home, and the total and fine dust loadings in
this house were 691 and 392 g/m2, respectively. This house was visibly dirty; four children
under 12 lived in this house with their parents, both of whom were smokers. The lowest
house dust loading was observed in home WNH, which had no carpet. There, the total and
fine dust loadings were 0.311 and 0.193 g/m2, respectively. There were two more houses that
did not have carpet (homes WNG and SNE). The fine dust loading was 0.372 g/m2 for WNG
and 10.5 g/m2 for SNE. The fine dust fractions in these homes represented 42 and 96 percent
of the corresponding total dust loadings.
The reported PAH concentrations in dust and soil in Appendix G are expressed in units
of ppm and based on the dry weights which are corrected for moisture content. Figure 5.3
illustrates B2 PAH concentration profiles in house dust, entryway dust, and pathway soil in
the four field studies. The PAH concentration profiles of the dust and soil samples are
34
-------
TABLE 5.3. ESTIMATED INDOOR AND OUTDOOR FINE PARTICLE-BOUND PAH
CONCENTRATIONS FROM THE PAH MONITOR AVERAGE RESPONSES
Concentration00, ng/m3
Household Code'31
Location
Indoor
Outdoi
PNA
inner city - Durham
240
9.4
PSB
inner city - Durham
1300
280
WNA
rural area - Apex
25
18
WNB
rural area - Holly Springs
100
13
WNC
rural area - Zebulon
96
45
WND
rural area - Zebulon
34
39
WNE
inner city - Durham
1100
160
WNF
inner city - Durham
2000
91
WNG
inner city - Durham
120
250
WNH
inner city - Durham
33
22
WNI
inner city - Durham
87
34
SNA
inner city - Durham
58
78
SNB
inner city - Durham
32
4.3
SNC
inner city - Durham
ND(C)
120
SND
inner city - Durham
6
18
SNE
inner city - Durham
39
100
SSF
inner city - Durham
440
52
SSG
inner city - Durham
700
32
SNH
rural area - Rougemount
5.8
3.7
SNI
rural area - Zebulon
8
13
SNJ
rural area - Zebulon
31
72
SSK
rural area - Zebulon
1100
12
SNL
rural area - Apex
6.1
18
SSM
rural area - Holly Springs
710
7.5
(a) The first letter denotes study code: P = pilot study, W = winter study, and S = summer study; the second
letter denotes smoking code: N = nonsmoker and S = smoker; and the third letter denotes household ID.
(b) The PAH monitor only responds to fine particle-bound PAH (< 1-2 fim).
(c) No data collected because of data system malfunction.
35
-------
10
U)
G\
00
a
EC
<
CL.
"S
0
pa
1
JL>
O
03
Qh
§
£
*o
-------
TABLE 5.4. TOTAL AND FINE FRACTION HOUSE DUST LOADING
BY HOUSEHOLD
Dust Loading, g/m2 Percent of Fine
Household00 Fraction, %
Total Fine Fraction (< 150 /mi)
PNA
1.97
0.962
49
PSB
27.4
23.8
87
WNA
4.54
2.27
50
WNB
39.2
22.8
58
WNC
27.0
21.9
81
WND
3.11
2.99
96
WNE
132
123
93
WNF
20.0
16.2
81
WNG
0.890
0.372
42
WNH
0.311
0.193
62
WN1
105
71.6
68
SNA
73.5
64.9
88
SNB
26.6
19.2
72
SNC
3.47
1.73
50
SND
1.69
0.985
58
SNE
17.7
10.5
59
SSF
691
392
57
SSG
14.4
13.5
94
SNH
5.78
4.03
70
SNI
3.88
2.55
66
SNJ
3.84
2.64
69
SSK
10.8
8.99
83
SNL
1.27
0.988
78
SSM
2.98
2.05
69
(a) The first letter denotes study code: P = pilot study, W = winter study, and S = summer study; the second
letter denotes smoking code: N = nonsmoker and S = smoker; and the third letter denotes household ID.
37
-------
House Dust
0 Entry way Dust
~ Pathway Soil
H
22
Two Home Winter Pilot
Study
Nine Home Winter Study
Nine Home Summer Study Four Home Summer Smoker
Study
Figure 5.3. B2 PAH Concentration Profiles in House Dust, Entryway Dust, and Pathway Soil
-------
different from those for the air samples. With few exceptions, the least abundant PAH was
the volatile two-ring PAH and the most abundant PAH were four- and five-ring PAH. The
general concentration trend for dust and soil was house dust > entry way dust > pathway
soil. Similar B2 PAH concentrations were observed among the smokers' and nonsmokers'
households. The concentrations of B2 PAH accounted for approximately half of the total
PAH in most dust and soil samples.
The reported PAH concentrations in the food samples in Appendix G are expressed in
units of ppb. The most abundant target PAH in most food samples was either naphthalene or
phenanthrene. Levels of most individual target PAH and B2 PAH were less than 1 ppb.
Figure 5.4 shows B2 PAH concentration profiles of adult and child's duplicate diet food
samples. In general, the PAH concentrations in adult food samples were higher than those in
child food samples within each household. The subjects' daily food intakes measured from the
duplicate-diet food samples are summarized in Table 5.5. The daily food intakes ranged from
762 to 4430 g for adult subjects and from 498 to 2296 g for child subjects. In general, the
daily food intakes of adult subjects were higher than those of child subjects.
DAILY POTENTIAL DOSE OF PAH
The subject's daily potential dose of target PAH was calculated for the inhalation (air),
nondietary ingestion (dust/soil), and dietary ingestion (food) pathways as described in
Chapter 4. The estimated daily PAH exposures expressed as ng/day through the three
pathways are summarized in Table H-l through H-4 in Appendix H. The estimated daily
potential PAH doses in ng/kg/day (normalized by the subject's body weight) are summarized
in Table 1-1 through M in Appendix I. The body weights of the subjects were not measured
in these studies, therefore, the average body weights from the U.S. EPA Exposure Factor
Handbook (25) were used for the calculation; these weights are 71.8 kg for adults and 17.4 kg
for children in the age range of these studies. It should be noted that the daily potential dose
was calculated from daily exposure estimates and subject's body weight by assuming
100 percent
39
-------
1.2
Adult Food
0 Child Food
m
Two Home Winter Pilot
Study
Nine Home Winter Study
Nine Home Summer Study Four Home Summer Smoker
Study
Figure 5.4. B2 PAH Concentration Profiles in Adult and Child Duplicate-Diet Food Samples
-------
TABLE 5.5. SUMMARY OF DAILY FOOD INTAKES FROM DUPLICATE-DIET
FOOD SAMPLES
Daily Food Intake, g
Household Code00
Adult Subject
Child Subject
PNA
2,883
1,520
PNB
762
693
WNA
1,932
1,543
WNB
884
801
WNC
1,985
1,635
WND
1,530
960
WNE
1,431
498
WNF
2,354
1,189
WNG
768
1,250
WNH
2,682
1,693
WNI
2,721
1,738
SNA
1,451
596
SNB
2,780
2,214
SNC
785
1,123
SND
2,788
665
SNE
1,300
1,873
SSF
1,505
2,296
SSG
2,257
1,234
SNH
3,186
1,491
SNI
2,363
1,914
SNJ
2,411
2,050
SSK
1,935
1,424
SNL
4,430
1,716
SSM
1,696
1,729
(a) The first letter denotes study code: P = pilot study, W = winter study, and S = summer study; the second
letter denotes smoking code: N = nonsmoker and S = smoker; and the third letter denotes household ID.
41
-------
absorption in the lung and stomach. Therefore, the daily potential doses of target PAH
reported here are the maximum estimates of the daily potential externally applied dose.
The children's potential doses of target PAH are higher than those of adults in the same
household. This is partly because the children have lower body weights. The adults' daily
doses of B2 PAH ranged from 0.12 to 15.3 ng/kg/day through inhalation, from 0.38 to
4.24 ng/kg/day through nondietary ingestion, and from 1.61 to 60.9 ng/kg/day through
dietary ingestion. Relatively high B2 PAH doses were observed for children that ranged
from 0.37 to 19.6 ng/kg/day through inhalation, from 2.62 to 29.2 ng/kg/day through
nondietary ingestion, and from 1.35 to 97.0 ng/kg/day through dietary ingestion. The ranges
of the potential daily doses of B2 PAH through inhalation and nondietary ingestion pathways
were of the same order of magnitude, and a greater dose range of B2 PAH through dietary
ingestion pathway was observed. Note that there were uncertainities in the potential dose
from the nondietary pathway, because children vary greatly in their hand-to-mouth activity,
which increases the ranges of dust and soil ingestion.
Figures 5.5 displays the average daily potential doses for B2 PAH of adult and child
subjects through inhalation (air), nondietary ingestion (dust/soil), and dietary ingestion (food)
pathways in the four field studies. The potential total daily dose of B2 PAH via the three
pathways ranged from 19.3 to 53.7 ng/kg/day for children and from 8.79 to 31.7 ng/kg/day
for adults. The children had higher potential doses of B2 PAH than did the adults. In the two
summer field studies, the children from the smokers' household had higher average potential
doses of B2 PAH via the inhalation pathway in comparison with the children from the
nonsmokers' household via the same pathway. This was mainly from the higher B2 PAH
concentrations in indoor air from smokers' households. However, a child's potential total
doses of B2 PAH through the three pathways were similar between these two studies.
Figure 5.6 displays the distributions of averages of all the adults' and all the children's
potential doses of total PAH and B2 PAH. Inhalation was the most important pathway for the
adults' and children's exposure to total PAH. This is mainly because high levels of
naphthalene were found in the air. The relative importance of the three pathways for adult's
and child's daily doses of total PAH was inhalation > dietary ingestion > nondietary
42
-------
60
50
0 Food
~ Dust/Soil
40
¦ Air
Adult - Child - Adult - Child - Adult - Child - Adult - Child -
Pilot Pilot Winter Winter Summer Summer Summer Summer
Smoker Smoker
Figure 5.5. Daily Potential Dose of B2 PAH for Adults and Children
-------
Adult - B2 PAH
Child - B2 PAH
4*
\24%
84%
Adult - Total PAH Child - Total PAH
61%
73%
Inhalation
Non-Dietary Ingestion
Dietary Ingestion
38%
26%
Figure 5.6. Estimated Daily Potential Doses for B2 and Total PAH
-------
ingestion. However, ingestion (dietary and nondietary) became an important pathway for
adults' and children's exposure to the non-volatile B2 PAH. For the B2 PAH daily doses, the
relative importance of exposure pathways was dietary ingestion > nondietary ingestion >
inhalation for children and dietary ingestion > inhalation > nondietary ingestion for adults.
CONCENTRATION PROFILES OF HYDROXY-PAH IN URINE SAMPLES
The hydroxy-PAH concentrations measured in the urine samples expressed in units of
ng/mL of urine and /xmole/mole of creatinine are summarized in Table J-l through J-4 in
Appendix J. Among the target analytes, 1-hydroxypyrene and 3-hydroxyfluoranthene were
detected in all urine samples. The remaining target analytes including 1- and
3-hydroxybenz[a]anthracene, 6-hydroxychrysene, 1- and 3-hydroxybenzo[a]pyrene and
6-hydroxyindeno[l,2,3-c,d]pyrene were detected in some samples. The concentrations of
1-hydroxypyrene ranged from 0.007 to 0.358 ng/mL (0.002 to 0.265 /^mole/mole) in adults'
samples and from 0.009 to 1.23 ng/mL (0.008 to 0.175 /^mole/mole) in children's samples.
The urinary metabolite 1-hydroxypyrene has been measured in occupationally exposed
workers, including coke oven workers, aluminum smelter workers, and road pavers (28-30).
The reported values of 1-hydroxypyrene in these exposed workers ranged from approximately
1 //mole/mole to >100 /imole/mole. These occupational levels are significantly higher than
the levels of 1-hydroxypyrene reported in the subjects from the 24 low-income families. This
is probably because the indoor PAH concentrations of the exposed workers were significantly
higher than the indoor levels in the microenviornments found in these study homes.
Figure 5.7 displays the average concentrations of the sum of target hydroxy-PAH
(referred as total hydroxy-PAH) in adult and child subjects' urine in the four field studies.
Similar average total hydroxy-PAH concentrations were observed in all four studies. Average
levels of total hydroxy-PAH in the urine samples of the smokers' children were only slightly
higher than those from the nonsmokers' children. In the summer, the highest concentration
(0.584 ^mole/mole) of total hydroxy-PAH was found in the composite urine sample from a
child living in the household where the highest number of cigarettes (34 cigarettes) was
45
-------
Two Home Winter Pilot Nine Home Winter Study Nine Home Summer Study Four Home Summer Study
Study - nonsmoker - nonsmoker - smoker
Figure 5.7. Hydroxy PAH Concentration Profiles in Subject's Urine Samples
-------
smoked during the 24-hr monitoring period. The total hydroxy-PAII concentration in the
corresponding adult smoker's urine sample was 1.03 ^mole/mole, which is the third highest
level found. The highest levels of total hydroxy-PAH in the winter studies were 3.48 and
1.28 /xmolc/mole in the urine samples from two nonsmokers.
STATISTICAL ANALYSIS
Descriptive statistics of measured PAH data, calculated daily PAH exposure data,
calculated daily PAH dose data and measured hydroxy-PAH data are presented in
Appendices K through N, respectively.
The data presented in these appendices are:
• Tables K-l to K-4 summarizing measured PAH data (indoor air, outdoor air,
household dust, entryway dust, pathway soil, and food) for each of the four studies
(two-home pilot, nine-home winter, nine-home summer, and four-home smoker
studies), respectively.
• Tables K-5 to K-l 1 summarizing measured PAH data for each sample medium
(indoor air, outdoor air, household dust, entryway dust, pathway soil, adult food,
and child food), respectively.
• Tables L-l to L-4 summarizing estimated daily PAII exposure (ng/day) by
pathways (inhalation, nondietary ingestion, and dietary ingestion) and subjects
(adults and children) for each of the four studies.
• Tables L-5 to L-7 summarizing estimated daily PAH exposure (ng/day) across four
studies by locations (inner city and rural area) and subjects (adults and children),
for each of the three pathways.
• Tables M-l to M-4 summarizing estimated daily PAH potential dose (ng/kg/day) by
pathways and subjects for each of the four studies.
• Tables M-5 to M-7 summarizing estimated daily PAH potential dose (ng/kg/day)
across four studies by locations and subjects, for each of the three pathways.
• Tables N-l to N-4 summarizing measured hydroxy-PAH by measurement unit
(ng/mL and ^mole/mole) and subjects for each of the four studies, respectively.
47
-------
• Tables N-5 to N-6 summarizing hydroxy-PAHs across four studies by locations and
subjects for each of the two measurement units (ng/niL and ^mole/mole),
respectively.
Tables 5.6 and 5.7 summarize the concentrations of B2 PAH and total PAH,
respectively, in multimedia samples in the four field studies by locations. The results show
that average B2 PAH concentrations in all sample media (air, dust, soil, and food) from inner
city homes were higher than those in the rural homes. Similar relative concentration trends
were noted for total PAH in adults' food samples. Average indoor B2 PAH concentrations in
inner city homes were approximately three times as high as those in the rural homes. The
average outdoor B2 PAH concentration in inner city areas was more than four times as high as
that in rural areas.
Figures 5.8 and 5.9 show the box plots for B2 PAH and total PAH concentrations by
sample media and by locations. In the box plot, the bottom and top edges of the box represent
PAH concentrations at the 25th and the 75th percentiles, respectively. The PAH median value
is showed at the outer horizontal line in the box. The central vertical line extends from the
box to a distance of at most 1.5 interquartile. The interquartile range is the distance between
the 25th and the 75th sample percentiles. Any data outside this range is marked with a dot.
As shown in these figures, B2 PAH and total PAH concentrations in the inner city were
generally higher than those in rural areas in multiple sample media. The highest total PAH
concentration (9900 ng/m3) found in a rural home (WND) in the winter study was mainly due
to the extremely high level of naphthalene (9700 ng/m3). If this data point were removed, a
higher ambient total PAH concentration trend would be shown in the inner city in comparison
with the rural area.
Tables 5.8 and 5.9 summarize the calculated daily potential doses of B2 PAH and total
PAH, respectively, for adults and children in the four field studies by locations. The daily
potential doses of B2 PAH and total PAH for children were higher than those for adults.
Inner city subjects (children and adults) had higher total B2 PAH daily potential doses than the
rural subjects did. Similar total PAH daily potential doses were observed for inner city and
rural subjects. Table 5.10 summarizes the sum of hydroxy-PAH (total hydroxy PAH) data in
48
-------
TABLE 5.6. SUMMARY OF B2 PAH CONCENTRATIONS IN THE FOUR FIELD STUDIES BY LOCATIONS
City (n
= 14)
Rural (n
= 10)
Overall (n = 24)
Media
Average
Standard
Deviation
Minimum
Maximum
Average
Standard
Deviation
Minimum
Maximum
Average
Standard
Deviation
Minimum
Maximum
Indoor Air (ng/m3)
6.86
7.73
1.40
27.32
1.96
1.31
0.42
4.83
4.82
6.36
0.42
27.32
Outdoor Air (ng/m1)
5.09
5.16
0.87
17.80
1.20
0.61
0.53
1.94
3.47
4.36
0.53
17.80
Household Dust (ppm)
2.22
1.45
0.46
5.98
1.03
0.27
0.69
1.41
1.73
1.25
0.46
5.98
Entryway Dust (ppm)
1.33
0.79
0.14
2.87
0.73
0.86
0.13
2.46
1.08
0.86
0.13
2.87
Pathway Soil (ppm)
0.62
0.58
0.05
1.77
0.09
0.09
0.02
0.31
0.40
0.51
0.02
1.77
Adult Food (ppb)
0.70
0.59
0.04
2.11
0.47
0.44
0.13
1.66
0.60
0.54
0.04
2.11
Child Food (ppb)
0.34
0.37
0.05
1.50
0.28
0.22
0.09
0.77
0.31
0.31
0.05
1.50
-------
TABLE 5.7. SUMMARY OF TOTAL PAH CONCENTRATIONS IN THE FOUR FIELD STUDIES BY LOCATIONS
City (n
= 14)
Rural (n
= 10)
Overall (n - 24)
Media
Average
Standard
Deviation
Minimum
Maximum
Average
Standard
Deviation
Minimum
Maximum
Average
Standard
Deviation
Minimum
Maximum
Indoor Air (ng/m1)
2220.04
1225.24
373.87
4560.18
2827.70
2652.37
1002.99
9891.51
2473.23
1922.24
373.87
9891.51
Outdoor Air (ng/m1)
764.18
669.03
125.00
2156.15
189.66
72.54
91.12
312.37
524.80
582.03
91.12
2156.15
Household Dust (ppm)
5.47
3.42
1.25
15.20
3.19
1.15
2.07
6.20
4.52
2.91
1.25
15.20
Entryway Dust (ppm)
3.43
1.99
0.44
6.58
2.04
1.94
0.42
5.56
2.85
2.05
0.42
6.58
Pathway Soil (ppm)
1.41
1.25
0.13
3.84
0.32
0.23
0.06
0.80
0.96
1.10
0.06
3.84
Adult Food (ppb)
17.11
12.37
5.28
43.13
15.00
12.13
1.83
43.84
16.23
12.05
1.83
43.84
Child Food (ppb)
7.97
4.10
1.90
13.62
11.93
17.70
0.86
61.07
9.62
11.66
0.86
61.07
-------
5-
CL
CL
a.
I
CM
m
Rural Inner
Area City
House Dust
Rural Inner
Area City
Entry way Dust
Rural Inner
Area City
Pathway Soil
30
•
•
•
1
L
1
' 0
r
20
05
c
<
a.
I
Csl
m
10
0
Rural Inner
Area City
Rural Inner
Area City
Indoor Air
Outdoor Air
Figure 5.8. Box Plots for B2 PAH by Sample Media and by Locations
51
-------
Rural Inner
Area City
Rural Inner
Area City
Rural Inner
Area City
House Dust
Entryway Dust
Pathway Soil
10000
9000-
8000-
7000
6000-
5000-
4000
3000
2000
1 000
0
Rural
Area
Inner
City
Indoor Air
Rural Inner
Area City
Outdoor Air
Figure 5.9. Boi Plots for Target FAHs by Sample Media and by Locations
52
-------
TABLE 5.8. SUMMARY OF POTENTIAL DAILY DOSES OF B2 PAH IN ADULTS AND CHILDREN IN THE
FOUR FIELD STUDIES BY LOCATIONS
City (n
= 14)
Rural (n
= 10)
Overall (n = 24)
Pathway
Average
Standard
Deviation
Minimum
Maximum
Average
Standard
Deviation
Minimum
Maximum
Average
Standard
Deviation
Minimum
Maximum
Adult Subjects, ng/kg/day
Inhalation (Air)
2.67
4.13
0.36
15.31
0.52
0.34
0.12
1.31
1.77
3.29
0.12
15.31
Nondietary Ingestion
(Dust/Soil)
1.65
1.05
0.38
4.24
0.77
0.20
0.49
1.04
1.28
0.91
0.38
4.24
Dietary Ingestion (Food)
17.59
17.88
1.61
60.86
14.47
15.59
3.99
54.53
16.29
16.68
1.61
60.86
Total Dose
21.91
17.69
4.12
62.02
15.76
15.50
5.15
55.51
19.35
16.75
4.12
62.02
Child Subjects, ng/kg/day
Inhalation (Air)
5.64
5.82
1.12
19.59
1.54
1.03
0.37
4.02
3.93
4.88
0.37
19.59
Nondietary Ingestion
(Dust/Soil)
11.53
7.00
2.62
29.16
5.16
1.23
3.34
6.92
8.88
6.21
2.62
29.16
Dietary Ingestion (Food)
23.00
23.96
1.35
96.99
27.25
24.47
6.74
76.28
24.77
23.74
1.35
96.99
Total Dose
40.17
23.56
15.00
107.41
33.96
24.70
12.17
83.23
37.58
23.71
12.17
107.41
-------
TABLE 5.9. SUMMARY OF POTENTIAL DAILY DOSES OF TOTAL PAH IN ADULTS AND CHILDREN
IN THE FOUR FIELD STUDIES BY LOCATIONS
City (n
= 14)
Rural (n
= 10)
Overall In = 24)
Pathway
Average
Standard
Deviation
Minimum
Maximum
Average
Standard
Deviation
Minimum
Maximum
Average
Standard
Deviation
Minimum
Maximum
Adult Subject
, ng/kg/day
Inhalation (Air)
625.30
374.81
139.74
1301.73
712.50
711.39
268.17
2644.12
661.63
528.55
139.74
2644.12
Nondietary Ingestion
(Dust/Soil)
4.05
2.44
1.04
10.76
2.42
0.98
1.55
4.97
3.37
2.10
1.04
10.76
Dietary Ingestion (Food)
412.70
294.85
100.90
1126.12
419.37
297.13
43.28
934.20
415.48
289.30
43.28
1126.12
Total Dose
1042.05
386.87
418.78
1628.58
1134.29
925.17
397.64
3583.29
1080.49
649.37
397.64
3583.29
Child Subject
. ng/kg/day
Inhalation (Air)
1757.71
897.33
432.46
3382.29
2140.20
2237.92
821.18
8183.09
1917.08
1565.88
432.46
8183.09
Nondietary Ingestion
(Dust/Soil)
28.37
16.41
7.17
73.97
16.25
6.70
10.86
34.18
23.32
14.39
7.17
73.97
Dietary Ingestion (Food)
554.90
315.65
161.66
1189.74
866.27
964.37
77.02
3369.26
684.64
666.95
77.02
3369.26
Total Dose
2340.98
879.62
1280.19
4233.96
3022.72
3177.08
932.27
11586.53
2625.04
2122.49
932.27
11586.53
-------
TABLE 5.10. SUMMARY OF TOTAL TARGET HYDROXY-PAH FOR ADULT AND CHILD SUBJECTS
IN THE FOUR FIELD STUDIES BY LOCATIONS
Adult Subject
Child Subject
Measurement
Number of
Standard
Number of
Standard
Location
Unit
Households
Average
Deviation
Minimum
Maximum
Households
Average
Deviation
Minimum
Maximum
ng/mL
14
0.96
1.04
0.25
4.19
14
0.45
0.46
0.06
1.86
City
//mole/mole
14
0.38
0.37
0.05
1.28
13
0.18
0.11
0.04
0.40
ng/mL
10
1.15
0.96
0.10
2.95
9
0.49
0.31
0.05
1.02
Rural
//mole/mole
10
0.77
1.00
0.08
3.48
9
0.34
0.18
0.04
0.58
ng/mL
24
1.04
0.99
0.10
4.19
23
0.47
0.40
0.05
1.86
Overall
/ymole/mole
24
0.54
0.71
0.05
3.48
22
0.25
0.16
0.04
0.58
-------
the four field studies by locations. Similar total hydroxy-PAH concentrations were found in
the urine samples from inner city and rural subjects.
It is of interest to know whether the levels of PAH in one sample medium are related to
their levels in other sample media. The correlation between the measured PAH concentrations
in different sample media was investigated. Pearson correlation coefficients were calculated
based on natural log-transformed data. Appendix 0 presents Pearson correlation
coefficients (r) for PAII levels in one sample medium with PAH levels in another sample
medium. The scatter plots of B2 PAH and total PAH concentrations in two different sample
media are presented in Figures 0-1 and 0-2 in Appendix 0. In these figures, the symbols C
and R stand for inner city data and rural data, respectively. As shown in Tables 0-1 and 0-2,
levels of PAH did not appear to be highly correlated in any of the different sample media.
Tabic 5.11 presents Pearson correlation coefficients for B2 PAH and total PAH in different
sample media. Among all sample media, the strongest relationship was observed between
outdoor air and house dust and between indoor air and outdoor air. In summary, there were
positive but weak relationships for PAH found among dust, soil, and air samples. There were
no strong direct relationships between the food samples and other types of environmental
samples.
Appendix P summarizes Pearson correlation coefficients (r) for total hydroxy-PAH in
urine samples with the estimated daily PAH dose levels. In general, the correlation between
the measured total hydroxy-PAH concentrations in subjects' urine samples and the calculated
subjects' daily potential dose of B2 PAH was weak. A similar weak relationship was
observed between the total hydroxy-PAH levels and the estimated daily potential dose of total
PAH.
Table 5.12 summarizes the results of the ANOVA models. The top third of the table
presents the results for B2 PAH, the middle third for total PAH, and the bottom third for
hydroxy PAH. Each row represents a distinct analysis. Columns three to five compare PAH
concentrations between rural and inner city homes. Geometric mean PAH concentrations for
rural homes and inner city homes are presented in the third and fourth columns, respectively.
Statistically significant differences are noted in the fifth column; one asterisk (*) denotes
56
-------
TABLE 5.11. PEARSON CORRELATION COEFFICIENTS FOR B2 PAH AND
TOTAL PAH BETWEEN DIFFERENT SAMPLE MEDIA
Correlation with Household Dust
Correlation with Entryway Dust
Media
Sum of B2
PAH
Sum of Target
PAH
Sum of B2
PAH
Sum of Target
PAH
Indoor Air
0.036
-0.071
0.166
-0.126
Outdoor Air
0.516**
0.479*
0.421*
0.316
Pathway Soil
0.328
0.204
0.473*
0.467*
Adult Food
0.234
0.332
-0.034
0.117
Child Food
0.169
0.194
-0.316
-0.029
57
-------
TABLE 5.12. SUMMARY OF ANALYSIS OF VARIANCE RESULTS
Geometric Mean
City
Geometric Mean
Smoker
PAH
Media
City
Rural
vs
Rural
Smoker
Non-
Smoker
vs
Non-Smokera
Sum of
Indoor Air (ng/m*3)
4.315
1.594
* *
6.139
1.382
* *
B2 PAHs
Outdoor Air (ng/mA3)
3.427
1.056
* *
1.061
1.265
House Dust (ppm)
1.825
1.000
*
1.228
1.511
Entryway Dust (ppm)
1.013
0.409
0.606
0.514
Pathway Soil (ppm)
0.347
0.062
* *
0.156
0.208
Food (ppb)
Adult
0.442
0.363
0.345
0.697
Child
0.215
0.227
0.261
0.404
Sum of
Indoor Air (ng/mA3)
1845.826
2179.162
1782.327
2213.082
Target
PAHs
Outdoor Air (ng/mA3)
House Dust (ppm)
528.827
4.663
176.642
3.050
* *
387.562
3.443
348.389
3.761
Entryway Dust (ppm)
2.718
1.364
1.965
1.724
Pathway Soil (ppm)
0.839
0.252
*
0.567
0.573
Food (ppb)
Adult
13.778
10.768
5.227
15.178
*
Child
6.786
5.985
2.734
5.006
Sum of
Urine (ng/mL)
Adult
0.664
0.765
0.882
0.525
Hydroxy-
PAHs
Child
0.303
0.367
0.444
0.299
Urine (//mole/mole)
Adult
0.245
0.452
0.524
0.190
Child
0.151
0.269
0.208
0.163
4-home smoker study conducted during summertime versus 9-home summer study conducted on non-smoker homes.
Effect is statistically significant at 0.05 level
Effect is statistically significant at 0.01 level
-------
statistically significant at the 0.05 level and two asterisks (**) denote statistically significant at
the Q.01 level. Columns six to eight compare PAH concentrations for the non-smokers in the
nine-home summer study and the smokers in the four-home smoker study. Geometric mean
PAH concentrations for homes in the nine-home summer study and homes in the four-home
smoker study are presented in the sixth and seventh columns, respectively. Statistically
significant differences are noted in the last column.
The primary result of the ANOVA is that B2 and total PAH concentrations measured
in inner city homes were significantly higher than those measured in rural homes for several
media: B2 PAH- indoor air, outdoor air, house dust, and pathway soil, total PAH- outdoor air
and pathway soil. There were no statistically significant differences in hydroxy PAH between
the rural and inner city homes for either children or adults. Indoor air B2 PAH and pathway
soil total PAH concentrations measured in the smokers' homes were significantly higher than
those in the nonsmokers' homes.
Table 5.13 summarizes the estimated relationships between hydroxy PAH and
estimated daily B2 PAH potential dose from inhalation, nondietary ingestion (dust and soil)
and dietary ingestion based on the fitted regression models. The top half of the table presents
the results for adults and the bottom half for children. Each row represents a distinct analysis.
The intercepts for the fitted regression models are shown in the second column, and the slopes
are displayed in columns three to five. The slope represents the estimated increase in log
transformed hydroxy PAH due to an increase of one in the log transformed estimated daily
potential dose. For each regression model, a test was conducted to determine if the relationship
between hydroxy PAH and the estimated daily potential doses were different between rural and
inner city homes. The last column indicates if that test was statistically significant.
Table 5.14 summarizes the estimated relationships between hydroxy PAH and estimated
total daily B2 PAH potential dose using the same format as Table 5.13. Tables 5.15 and 5.16
summarize the results for the models that utilized total PAH potential dose as the estimated daily
dose factor.
The primary result of the regression models is that none of the estimated daily PAH
potential dose factors were significantly related to hydroxy PAH for either children or adults. In
59
-------
TABLE 5.13. REGRESSION ANALYSIS RESULTS FOR TOTAL HYDROXY-PAH
VERSUS ESTIMATED B2 PAH POTENTIAL DOSE (/ig/kg/day)
Parameter Estimates
OH-PAH Unit
Intercept
Inhalation
(Air)
Nondietary
Ingestion
pathway
(Dust/Soil)
Dietary
Ingestion
pathway
(Food)
Location
Effect
(p-value)
Adult
ng/mL
0.085
0.221
-0.284
0.150
Not Sig.
(0.699)
// mole/mole
0.449
0.304
-0.090
-0.101
Not Sig.
(0.144)
Child
ng/mL
3.916
0.191
0.473
0.300
Not Sig.
(0.310)
fj mole/mole
-0.332
0.152
-0.004
-0.005
Not Sig.
(0.145)
Note: None of the parameter estimates are significantly different from zero at 0.05 level.
TABLE 5.14. REGRESSION ANALYSIS RESULTS FOR TOTAL HYDROXY-PAH
VERSUS ESTIMATED B2 PAH POTENTIAL TOTAL DOSE (/ig/kg/day)
Parameter Estimates
Location Effect
OH-PAH Unit Intercept Total Dosages" (p-value)
Adult
ng/mL
0.201
0.106
Not Sig.
(0.676)
fj mole/mole
-1.517
-0.163
Not Sig.
(0.205)
Child
ng/mL
1.142
0.611
Not Sig.
(0.450)
// mole/mole
-0.616
0.198
Not Sig.
(0.084)
Note: None of the parameter estimates are significantly different from zero at 0.05 level.
a) Sum of B2 PAH dosage through all three pathways that is, the sum of B2 PAH dosages through
inhalation pathway (air), nondietary ingestion pathway (dust/soil), and dietary ingestion
pathway (food).
60
-------
TABLE 5.15. REGRESSION ANALYSIS RESULTS FOR TOTAL HYDROXY-PAH
VERSUS ESTIMATED TARGET PAH POTENTIAL DOSE (^g/kg/day)
Parameter Estimates
OH-PAH Unit
Intercept
Nondietary
Ingestion
Inhalation Pathway
Pathway (Air) (Dust)
Dietary
Ingestion
pathway
(Food)
Location
Effect
(p-value)
Adult
ng/mL
-0.994
0.379
-0.158
0.006
Not Sig.
(0.903)
// mole/mole
-0.720
0.086
0.041
-0.195
Not Sig.
(0.224)
Child
ng/mL
1.287
-0.447
0.527
-0.143
Not Sig.
(0.306)
fj mole/mole
-1.625
-0.192
-0.081
-0.085
Not Sig.
(0.165)
Note: None of the parameter estimates are significantly different from zero at 0.05 level.
TABLE 5.16. REGRESSION ANALYSIS RESULTS FOR TOTAL HYDROXY-PAH
VERSUS ESTIMATED TARGET PAH POTENTIALTOTAL DOSE
Oxg/kg/day)
Parameter Estimates
OH-PAH Unit
Intercept
Total Dosages9
Location Effect
(p-value)
Adult
ng/mL
-0.240
0.332
Not Sig.
(0.688)
// mole/mole
-0.808b
-0.166
Not Sig.
(0.176)
Child
n9/mL -0.630 -0.485 K3 646)'
fj mole/mole ^ Q9() _Q NotSig.
a) Sum of target PAH dosage through all three pathways, that is, the sum of target PAH dosages through
inhalation pathway (air), nondietary ingestion pathway {dust/soil), and dietary ingestion pathway (food).
b) Parameter estimate is significantly different from zero at 0.05 level.
61
-------
fact, exactly one half of the slopes were estimated to be negative. The relationship between
1-hydroxypyrene and the estimated daily potential dose of pyrene was examined. A similar
weak relationship was observed. The absence of significant relationships between hydroxy PAH
and the estimated daily potential dose factors may be due to the small sample size, and the
estimates of body weights, inhalation rates and ingestion rates. The elimination rate for urinary
PAH metabolites may also vary among subjects. This variation could contribute to the weak
relationships between the hydroxy-PAH concentrations in urine samples and the estimated daily
potential doses of PAH.
QUALITY CONTROL
Known amounts of perdeuterated PAH were spiked into each air, dust, soil, and food
sample prior to sample preparation. Table 5.17 summarizes the recovery data of the spiked PAH
for each type of sample. Quantitative recoveries (>80%) of the spiked PAH were obtained in
most of the samples. The low recoveries of fluorene-di0 in the food samples are presumably due
to the losses during the refluxing process.
Duplicate samples of each sample media were analyzed in the two-home pilot study to
document the overall method precision. The overall method precision for multiple sample media
was estimated based on analytical results for duplicate field samples. The percent relative
standard deviations (% RSD) for measured concentrations of target PAH and hydroxy-PAH in
duplicate samples are summarized in Tables 5.18 and 5.19. The overall method precision for
measuring target PAH was within ±15 percent. The precision for measuring hydroxy-PAH in
urine samples was within ±24 percent.
Table 5.20 summarizes the results of target PAH found in the field blanks for each type
of sample in the four field studies. In general, only tTace amounts of target PAH were found in
the field blanks. All the reported data were corrected for the field blanks. None of the hydroxy-
PAH were found in the method blanks for urine samples. These results showed that there was no
significant contamination due to sample handling and preparation.
62
-------
TABLE 5.17. SUMMARY OF RECOVERY DATA OF SPIKED PERDEUTERATED
PAH IN MULTIMEDIA SAMPLES
Compound
Recovery(a), %
Field Study
Air
Dust/Soil
Food
Two-home Pilot Studv
Fluorene-d,0
97 ± 10
91 ± 7.4
64 ± 10
Pyrene-d10
102 + 4.3
99 + 3.0
81 ± 0.9
Chrysene-d10
113 + 7.5
97 ± 6.4
99 ± 3.6
Benzo[k]fluoranthene-d12
108 ± 7.5
97 ± 2.2
93 ± 4.3
Perylene-d12
108 ± 7.5
99 ± 3.0
100 ± 2.9
Nine-home Winter Studv
Fluorene-d10
100 ± 3.9(b)
90 + 8.9
42 ± 37
Pyrene-d]0
98 ± 5.3
91 + 12
89 ± 3.6
Chrysene-d10
100 ± 10
88 + 12
79 ± 7.4
Benzo[k] fluoranthene-d 12
93 ± 10
89 ± 9.9
82 ± 7.6
Perylene-d12
96 ± 8.6
93 + 11
76 ± 6.7
Nine-home Summer Studv
Fluorene-d,0
100 ± 9.6
90 ± 7.7
27 ± 15
Pyrene-d10
96 ± 4.6
90 ± 6.4
96 ± 6.0
Chrysene-d12
97 ± 4.3
92 ± 7.3
98 ± 5.2
B enzo [k] fluoranthene-d n
92 ± 4.4
95 ± 6.3
96 ± 6.1
Perylene-d]2
88 ± 4.5
92 ± 7.0
89 ± 6.5
Four-home Smoker Studv
Fluorene-d10
100 ± 7.7®
95 ± 8.4
19 ± 12
Pyrene-dl0
96 ± 6.6
91 ± 7.1
96 ± 13
Chrysene-d12
98 ± 8.5
94 ± 5.4
94 ± 9.4
Benzo [k] fluoranthene-d, 2
94 ± 6.2
94 ± 7.2
93 ± 7.2
Perylene-d,,
90 ± 2.9
90 ± 4.8
90 ± 6.4
(a) The report value is avg ± std. dev.
(b) The recoveries of fluorene-d10 cannot be measured in 7 (3 winter study and 4 smoker
study) indoor air samples due to interference peaks.
63
-------
TABLE 5.18. PERCENT RELATIVE STANDARD DEVIATIONS (% RSD)
FOR PAH IN DUPLICATE MULTIMEDIA SAMPLES
% RSD(b)
Compound'*0
Air
HD
ES
PS
Adult's
Food
Child's
Food
Naphthalene
3.2
7.5
3.8
1.6
6.0
1.3
Acenaphthylene
0.05
4.8
9.5
NA
13
4.1
Acenaphthene
3.1
6.1
1.6
9.6
0.49
1.7
Fluorene
1.9
3.4
6.3
6.0
5.5
1.9
Phenanthrene
5.2
6.3
4.5
11
0.09
3.8
Anthracene
1.5
3.7
7.2
3.9
7.6
3.0
Fluoranthene
6.1
8.6
9.1
12
1.0
4.9
Pyrene
7.2
5.5
5.8
2.2
3.6
3.4
Benz [a] anthracene*
7.0
0.88
11
13
13
2.1
Chrysene*
3.8
0.56
11
12
8.6
6.7
Cy clo opentafc, dl pyrene
9.0
4.6
11
NA
8.4
3.9
Benzofluoranthenes*
0.07
1.2
8.7
1.8
15
0.77
Benzo[e]pyrene
2.0
0.51
8.5
12
1.4
4.1
Benzo[a]pyrene*
2.1
0.60
8.3
5.9
13
1.2
Indeno[l,2,3-c,d]pyrene*
2.3
11
10
8.2
9.4
9.3
Dibenzo [a,h] anthracene *
6.0
11
10
11
8.6
NA
Benzo [g ,h, i]pery lene*
0.34
2.1
8.1
1.1
5.6
7.5
Coronene
7.1
5.7
10
0.56
1.1
1.8
(a) *The PAH compounds are ranked as probable human carcinogens (B-2) by the U.S.
EPA's Integrated Risk Information System.
(b) HD denotes house dust; ES denotes entryway dust; and PS denotes pathway soil.
(c) NA denotes data are not available because this analyte was not deteted in the samples.
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TABLE 5.19. PERCENT RELATIVE STANDARD DEVIATIONS (% RSD)
FOR HYDROXY-PAH IN DUPLICATE URINE SAMPLES
Compound % RSD
3-Hydroxyfluoranthene 16
1-Hydroxypyrene 10
l-Hydroxybenz[a]anthracene 20
6-Hydroxychrysene 10
3-Hydroxybenzo[a]anthracene 24
l-Hydroxybenzo[a]pyrene 16
6-Hydroxymdeno[l,2,3-c,d]pyrene M-
65
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TABLE 5.20. LEVELS OF TARGET PAH FOUND IN FIELD BLANKS
Compound(a)
Total Amount, ng^
Air
Dust/Soil
Food
Naphthalene
251 (193-340)
17 (< 1-34)
23 (10-36)
Acenaphthylene
1.4 (< 1-2.2)
<1
<1
Acenaphthene
12 (7.0-12)
<1
7.2 (1.9-14)
Fluorene
11 (1.9-21)
2.2 (< 1-5.6)
6.8 (4.1-12)
Phenanthrene
73 (41-110)
11 (< 1-26)
55 (88-25)
Fluoranthene
24 (18-28)
4.3(< 1-12)
28 (5.8-55)
Pyrene
17 (14-19)
1.6 (< 1-3.8)
14 (2.9-29)
Cy clopenta [c, d ]py rene
<1
<1
<1
Benz [a] anthracene *
<1
<1
1.5 (< 1-2.9)
Chrysene*
<1
<1
1.1 (< 1-1.4)
Benzofluoranthenes *
<1
<1
1.4 (< 1-3.2)
Benzo[e]pyrene
<1
<1
<1
Benzo[a]pyrene*
<1
<1
<1
Indeno [ 1,2,3-c, d] pyrene*
<1
<1
<1
Dibenzo [a, h] anthr ecene *
<1
<1
<1
Benzo[g,h,i]perylene
<1
<1
<1
Coronene
<1
<1
<1
(a) *The PAH compounds are ranked as probable human carcinogens (B-2) by the U.S.
EPA's Integrated Risk Information System.
(b) The reported value is average (range) of the same type of field blanks from all field
studies.
66
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NERL-RTP-O-578 TECHNICAL REPORT DATA
1. REPORT NO.
600/R-98/163a
2.
i
4. TITLE AND SUBTITLE
Polycyclic Aromatic Hydrocarbon Exposure of Children in Low-
Income Families
Voluimf, 1: Report
5.REPORT DATE
6.PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Jane C. Chuang et al.
8.PERFORMING ORGANIZATION
REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Battelle Memorial Institute
505 King Avenue
Columbus, Ohio 43201
10.PROGRAM ELEMENT NO.
Projects E0608 and E0460
11. CONTRACT/GRANT NO.
Cooperative Agreement CR822073
and Contract 68-D4-0023
12. SPONSORING AGENCY NAME AND ADDRESS
National Exposure Research Laboratory
U. S. Environmental Protection Agency
Research Triangle Park, NC 27711
13.TYPE OF REPORT AND PERIOD
COVERED
Published Report, 12/93-12/97
14. SPONSORING AGENCY CODE
EPA/600/09
15. SUPPLEMENTARY NOTES
16. ABSTRACT
In four small studies, the exposures of preschool children lo polycyclic aromatic hydrocarbons (PAH) through dietary
ingestion, nondietary ingestion, and inhalation were examined. Data were combined to estimate PAH exposures and
potential doses for children in 24 families. In air, indoor PAH levels were higher than those outdoors, and in smokers'
homes compared to nonsmokers' homes. Outdoor air PAH levels were higher in inner cily compared to rural areas. The
relative concentrations of PAH in dust and soil were house dust > entry way dust > pathway soil. The PAH
concentrations in adults' food were higher than those in children's food. However, children's potential daily doses of PAH
were higher than those of adults in the same households. Inhalation was an important pathway for children's exposure to
total PAH, but dietary and nondietary ingestion were more important for exposure to B2 PAH (probable human carcino-
gens). Statistical analysis suggested that inner city children have higher exposure to B2 PAH than do rural children.
17. KEY WORDS AND DOCUMENT ANALYSIS
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