EP A/600/A-96/086
Evaluation of Field Methods for Estimating Exposure of Children in Low-Income
Families to Polycyclic Aromatic Hydrocarboi
Nancy K. Wilson
U. S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
Jane C. Chuang
Battelle, 505 King Avenue, Columbus, Ohio 43201, USA
Christopher Lyu
Survey Research Associates, 100 Capitola Drive, Durham, North Carolina 27713
ABSTRACT
Children in low-income families may have higher exposures to polycyclic aromatic hydrocarbons
(PAH) and related compounds than children in higher-income families. These higher exposures could
result from the location of their homes, nearer to industrial sites and traffic; from poorer diet; from
environmental tobacco smoke; or other causes. This study was designed to evaluate methods and
estimate the range of total exposures of low-income children to PAH through various pathways.
Nonsmoking participants with preschool children, incomes at or below the official US poverty level, and
space heating in their homes were recruited. The PAH concentrations were measured in the household
indoor and outdoor air, house dust, and yard soil, and in the diet of both an adult and a preschool child
living in the home. An initial study in two homes and an additional study of nine homes, four urban and
five rural, during the heating season were completed. The problems and successes encountered in the
recruitment process and selected results of the heating season measurements are summarized in this
paper.
INTRODUCTION
One of the many unanswered questions regarding exposure to polycyclic aromatic hydrocarbons
(PAH) is whether persons living in low-income families have greater exposures to these compounds
because of environmental factors such as living near industrial sites or heavy traffic, or lifestyle factors
such as smoking, inadequate diet, or participation in activities that increase such exposures. Because
preschool children may be more sensitive to these exposures, an investigation into the exposures of such
children is especially important. Before a large-scale study to answer the above question can be designed,
the field sampling and analysis methods must be developed and evaluated in real exposure situations.
In an initial study, recruitment, field sampling, and analytical methods were evaluated in two urban
homes, one occupied by smokers and one by nonsmokers. Then, on the basis of the results of the two-
home study, a more detailed methods evaluation study was carried out in nine homes, four urban and five
rural, in and around Durham, North Carolina. In the latter study, participants were selected on the basis
of their location, use of space heating, no resident smokers, at least one adult and one preschool, toilet-
trained child who stayed at home, and family income at or below the U. S. poverty level. In each home,
an adult and a preschool child participated. Polycyclic aromatic hydrocarbon concentrations were
measured in the household indoor and outdoor air, soil and house dust, and in the individuals' diets.
Twenty-four hour urine samples were also obtained for some of the participants, to evaluate the
collection and analytical methods for selected urinary metabolites of PAH; however, these metabolite
results are not discussed herein.
The aim of this study was threefold: to evaluate field methods for determining children's exposure
to PAH for use in the design of a potential larger study, to estimate the ranges of these potential
exposures through all environmental media, and to estimate the ranges of the subjects' total exposures.
In this paper, we discuss the successes and failures of the participant recruitment process and summarize
selected results of the heating season measurements.

-------
METHODS
Questionnaires and other study materials were developed and tested first in two homes, as were
several of the field methods. From the results from these two homes, we found it necessary to revise
both the printed materials and the recruitment process. The two-home study and the lessons that we
learned from it are summarized briefly below.
Two-Home Study
The initial recruitment process consisted of door-to-door counting and listing of homes in low-
income neighborhoods, followed by contacting residents by telephone and in person, and administering a
brief screening questionnaire. In addition to having an adult and a preschool, toilet-trained child living at
home, the criteria included family income below the U. S. poverty level, as indicated by receipt of some
sort of social services, such as Aid to Families with Dependent Children (AFDC) or food stamps, and use
of unvented combustion space heating. After extensive effort, we were unable to locate households that
met these criteria: 631 households were screened, and none met all the criteria. Even when the unvented
space heating requirement was eliminated, only four households were identified and recruited.
The field sampling and analytical methods for the two homes were identical to those used in the
nine-home study. They will be summarized in a later section of this paper.
Several lessons were learned from the two-home study. In addition to the severe problem of
recruiting participants, we found that a significant education effort was required to assure the individuals
that the sampling and sampling equipment would not cause them harm. Prior to the field effort, HUB
approval of the study design and questionnaire was obtained from all three participating institutions.
Both the adult participant and other adults or domestic partners living in the home had to be made aware
of the intent and innocuousness of the study. Although informed consent was necessary only for the
individual subjects, we found it prudent to have all the adult residents discuss the study with us and sign a
consent form.
The participants had great difficulty understanding and carrying out instructions. Therefore, we
had to simplify, and simplify again, our participant instruction booklets and activity diaries. Participants
often did not keep their appointments, and occasionally moved away unexpectedly. Thus, to ensure
success of a study with the type of criteria that we employed, it is necessary to select several backup
homes and include them in all premonitoring activities.
A final seemingly small, but important, finding was that it is necessary, when using the duplicate
plate dietary sample collection method in this type of study, to furnish a portion of the incentive payment
ahead of time. This covers the cost of the extra food that must be prepared and supplied to the
investigators for analysis.
Nine-Home Study
Following the above study, a study in nine homes was carried out, using the information and
lessons learned from the two-home studies. The methods are summarized below.
Recruitment. Five methods were used to attempt to recruit participants. To recruit urban
residents, telephone screening of homes located along those streets that bore heavy traffic, and similar
telephone screening of homes located in a census tract known to have a large portion of low-income
residents were tried. Neither of these was successful. To recruit rural residents, both mail contacts and
telephone contacts were tried. These likewise were unsuccessful. However, with cooperation from the
county social services offices, food stamp office, and health department, both urban and rural participants
were enlisted successfully through a combination of flyers mailed to homes and posters in the various
offices, which provided a short description of the study, mentioned a small financial inducement, and gave
a telephone number which could be called for more information.
All homes that were selected for participation had a preschool, toilet-trained child at home and
had no smokers in the household. Their family income was below the U. S. poverty level or the family
received public assistance. In addition, the residents had lived there at least one year and did not plan to
move in the next six months, and the home had only one story or was a ground-floor apartment. The

-------
urban homes were near heavy traffic, whereas the rural homes were far from heavy traffic. For each
study home, there was at least one corresponding backup home, should sampling not be possible at the
original home for some reason,
Premonitoring Activities. One month before sampling, staff visited each of the participants,
including potential participants in the backup homes. At these visits, staff explained the study in detail,
answered any questions, and obtained informed consent from the participating adult and domestic
partner, if any. A premonitoring questionnaire was administered. Additionally, a new doormat for
collection of entryway soil was placed just outside the entrance.
One week before sampling, staff visited the participants again. At that time any additional
questions were answered, the participant information booklet was explained in detail, the child and adult
activity diaries were also explained, and instructions for food and urine sample collection were given. A
partial incentive payment was given to the participants, to cover the cost of extra food that they would
furnish for the dietary sample collection.
Field Monitoring. The field monitoring took place in the winter of 1994-1995. Each home was
sampled for 24 hr. Both indoor and outdoor air were sampled, using an integrated quartz fiber filter and
XAD-2 resin sorbent cartridge in a sampler operating at a flow rate of approximately 15 L/min. Real-
time fine particle-associated PAH were monitored indoors and out (EcoChem PAS 1002i, EcoChem
Technologies, West Hills, CA), and air exchange was monitored with a PFT tracer. House dust was
collected with an HVS3 house dust sampler [Cascade Stack Sampling Systems (CS3) Inc., Bend, OR],
using an ASTM method.1 Yard and entryway soil were also collected; the yard soil by scraping a 2-in
deep sample in the middle of the yard, and the entryway by turning the doormat, which we had placed a
month previously, upside down on aluminum foil and banging it vigorously. Food samples were collected
by the duplicate plate method.2"4 Total 24-hr urine samples were collected by the participant, using a
bonnet that fit under the toilet seat; the bonnet contents were emptied into a collection jar for each
individual after each use. In addition, temperature, relative humidity, wind speed, and wind direction data
were collected by means of a meteorological tower that was erected in the back yard of the home.
To protect the outdoor sampling equipment from the elements, the susceptible pumps and
electronic devices were placed in an unoccupied dog house, which was purchased new for the study. To
protect the indoor sampling equipment from inquisitive investigation by the preschool occupants of the
homes, the equipment was placed in a playpen, which likewise was purchased for the study.
Analysis. Air filter/sorbent cartridges were extracted with dichloromethane (DCM), and the
extracts were analyzed by gas chromatography/mass spectrometry (GC/MS) using selected ion
monitoring. Dust and soil samples were sieved into coarse ( >150 ^m) and fine fractions; the fine
fractions were then extracted with hexane and analyzed similarly. Food samples were refluxed with
KOH, extracted with hexane, treated with KOH, HC1, and water, fractionated with silica gel, and
analyzed by GC/MS. Urine samples were extracted with acidified DCM, methylated, fractionated with
silica gel; the hexane/DCM fraction was then analyzed by GC/MS. An aliquot of the original urine
samples was sent for creatinine analysis (SmithKline Beecham Clinical Laboratories, Dallas, TX). Details
of these analyses are provided elsewhere.5
The target PAH were: naphthalene, quinoline, acenaphthylene, acenaphthene, fluorene,
phenanthrene, anthracene, fluoranthene, pyrene, cyclopenta[c,d\pyrene, benzo[e]pyrene,
benz[a]anthracene, chrysene, benzofluoranthenes (three isomers), benzo[a]pyrene,
indeno[l,2,3-c,
-------
urban and rural settings. Outdoor concentrations were similar in both types of location, but indoor
concer ations in the rural homes were much higher than those in the urban homes tested. The sum of
the B-2 PAH averaged 2.14 ng/m3 indoors and 2.01 ng/m3 outdoors at the rural homes, essentially
equr it. However, the sum of the B-2 PAH at the urban homes was substantially higher indoors than
out : 9.22 ng/m3 indoors and 5.93 ng/m3 outdoors.
food, :he sum of 21 target PAH concentrations averaged 18.7 ppb for the adults and 14.5 ppb
for ildren. The B-2 PAH averaged 0.359 ppb for the adults and 0.129 ppb for the children.
A! the total PAH in the children's diets appeared similar to that in adults' diets, the adult diets had
hii sis i.. the B-2 PAH.
>il concentrations of PAH were highest in the house dust, somewhat lower in the entryway soil,
an ;t in the yard soil. House dust concentrations of the 21 PAH averaged 3.96 ppm, and those of
th AH averaged 1.57 ppm.
Pe i Dose Estimates
he total potential daily dose (the maximum dose) of PAH received by an individual can be
est. 1 from the following equations:
ff = Ax V/1000	(1)
wi is the inhalation dose, A is the air concentration in ng/m3, and V is the ventilation volume per
da
2 = FxM	(2)
w	is the dietary ingestion dose, F is the diet concentration in yg/kg, and M is the mass of food
er. '-g/day,
, = DxQ	(3)
wl	s the nondietary ingestion dose, D is the dust concentration in yg/g, and Q is the mass of dust
inj. .1 g/day, and the total dose is given by the sum of the doses through the environmental media
— Dj + D2 + JD}	(4)
wh 2 total potential dose T is in n g/day. We assumed that the inhalation volume of an adult is 20
nr nd that of a child is 15 m3/day;8 that the mass of dust/soil ingested by an adult is 0.06 g/day, and
th child is 0.1 g/day;9 and that no routes of exposure other than inhalation and ingestion are
sit it.
sing Equations (1) through (3) the calculated adult doses of total PAH ranged from 0.1 to
0.. iy in dust, 10 to 65 y g/day in food, and 20 to 185 y g/day in air- For most adult subjects,
inh i was the most prevalent route of intake of total PAH. The adult doses of B-2 PAH ranged from
OX 35 y g/day in dust, 0.22 to 1.43 fig/day in food, and 0.02 to 0.31 yg/day in air. For all but two
off ult sub sets, dietary ingestion was the most: nportant route of intake of B-2 PAH. Even for
the; ), the dose through the inhalation route was only slightly higher than that through diet.
-he calculated doses of total PAH for children ranged from 1 to 3 y g/day from dust, 8 to
58 nfe, ;.y from food, and 12 to 145 yg/day from air. Thus, with one exception, total PAH exposure of
these children was predominantly through the inhalation pathway, just as it was for the adults. However,
a different picture emerges for the children's exposure to B-2 PAH, as illustrated in Figure 1. The
children's doses of B-2 PAH ranged from 0.06 to 0.31 yg/day from dust, 0.03 to 0.33 yg/day from food,
and 0.02 to 0.32 (ig/day from air. For all but two children, ingestion was a more important route of
exposure to B-2 PAH than inhalation, and nondietary and dietary ingestion were of the same magnitude.
-------
The total exposures to PAH, calculated using Equation (4) for the adult subjects, indicated that
approximately 64% of their exposure, which is heavily influenced by the high concentrations of
naphthalene in air, comes from inhalation, aid 36% comes from food. Likewise, for the child subjects,
approximately 72% of their exposure comes from inhalation, and 28% comes from food. However, for
both adults and children, most of the exposure to B-2 carcinogenic PAH in this study derived from
ingestion, and for children, about half of this ingestion was nondietary. This is illustrated in Figure 2.
CONCLUSIONS
For this sample of low-income, nonsmoking adults and children, inhalation is the most important
pathway for total exposure to polycyclic aromatic hydrocarbons. However, ingestion is the most
important pathway for total exposure to the carcinogenic PAH. And for young children, nondietary
ingestion is as important as ingestion of food for exposure to the carcinogenic PAH.
Additionally, recruitment of participants to studies of this type is difficult. An effective means of
recruitment is to work through the various social service agencies, using flyers and posters and inviting
interested persons to initiate contact.
ACKNOWLEDGMENTS
We appreciate the help given and extend our thanks to the following: Margaret R. Pennybacker,
Frances Patterson, and Wallace Lambert of Survey Research Associates for help in questionnaire design
and the field survey; Patrick J. Callahan of Battelle and Andrew Matovu and Milton Bowen of EPA for
assistance in field monitoring; Robert G. Lewis of EPA for the use of the HVS3 house dust sampler; Jerry
Crescenti of NOAA for the use of meteorological equipment; and Mary Pollard, David B. Davis, and
Vanessa R. Katona of Battelle for help in sample preparation and analysis. Funding was supplied by the
U. S. Environmental Protection Agency through in-house support and through Cooperative Agreement
CR822073.
This paper has been reviewed in accordance with the United States Environmental Protection Agency's peer and
administrative review policies and approved for publication. Mention of trade names or commercial products does not constitute
endorsement or recommendation for use.
REFERENCES
1.	Standard Practice for Collection of Dust from Carpeted Floors for Chemical Analysis. Draft
Standard Method D.5438-93, Annual Book of ASTM Standards. American Society for Testing
and Materials, Philadelphia, 1994; Vol. 11.03.
2.	Waldman, J.M; Lioy, P.L.; Greenberg, A.; Butler, J.P. J. Exposure Anal. Environ. Epidemiology
19911, 193-225.
3.	Buckley, T.J.; Waldman, J.M.; Dhara, R.; Greenberg, A.; Ouyang, Z.; Lioy, P.J. Int. Arch.
Occup. Environ. Health 1995 62, 257-266.
4.	De Vos, R.H.; Van Dokkum, W.; Schouten, A.; Jong-Berkhout, P. Fd. Chem. Toxicol. 1990 28.
263-268.
5.	Chuang, J.C.; Callahan, P.J.; Lyu, Christopher; Characterization of Polycyclic Aromatic
Hydrocarbon Exposure Among Children of Low-Income Families from Inner Cities and Rural
Areas; Report for Year 2 Effort, Cooperative Agreement CR822073; U.S. Environmental
Protection Agency: Research Triangle Park, 1995.
6.	I ARC Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans:
Polynuclear Aromatic Compounds, Bituminous, Coal-Tar and Derived Products, Shale Oils and
Soots. International Agency for Research on Cancer, Lyon, France, 1985; Vol. 35, Part 4.
7.	U.S. Environmental Protection Agency Integrated Risk Information System.
8.	California Code of Regulations 22.2§12721(d)(2)(A); Barclays Law Publishers, San Francisco,
CA, 1995; Vol. 28, pp 195-196.
9.	Stanek, E.J., III; Calabrese, E. J.; Human and Ecological Risk Assessment 19951, 133-156.
-------
PAH, ug/day
0.35
IT1 ¦ III ¦ I ¦ I
1111 mi r r i
r r r,p i'i r i i i
AC BC CC DC EC FC GC HC IC
Subject Code
Figure 1. Children's exposure to B-2 carcinogenic polycylic aromatic hydrocarbons through three
routes (environmental media): inhalation (air), dietary ingestion (food), and nondietary
ingestion (dust/soil).
Adult
Child
Dust 38.5%
Figure 2. Comparative total exposure of adults and children to B-2 carcinogenic polycyclic aromatic
hydrocarbons from three environmental media: air, food, and dust/soil.
-------
Key Words
polycyclic aromatic hydrocarbons
PAH
exposure
human exposure
children
low-income
-------
TECHNICAL REPORT DATA
1 ^Woo/a-96/086 2
3.R1
4. TITLE AND SUBTITLE
Evaluation of field methods for estimating exposure of children in
low-income families to polycyclic aromatic hydrocarbons
5.REPORT DATE
6.PERFORMING ORGANIZATION CODE
7. AUTHOR (S)
Nancy K. Wilson, Jane C. Chuang, and Christopher Lyu
8.PERFORMING ORGANIZATION REPORT
NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
National Exposure Research Laboratory
U. S. Environmental Protection Agency
Research Triangle Park, NC 27711
and
Battelle, Columbus, OH 43201
10.PROGRAM ELEMENT NO.
Issuse 28, Project E0608 and Issue 28,
Project E0460
11. CONTRACT/GRANT NO.
Competitive cooperative agreement
CR822073
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
Symposium proceedings
14. SPONSORING AGENCY CODE
EPA/600/09
15. SUPPLEMENTARY NOTES
16. ABSTRACT
Children in low-income families may have higher exposures to polycyclic aromatic hydrocarbons (PAH) and
related compounds than children in higher-income families. These higher exposures could result from the location of their
homes, nearer to industrial sites and traffic; from poorer diet; from environmental tobacco smoke; or other causes. This
study was designed to evaluate methods and estimate the range of total exposures of low-income children to PAH through
various pathways. Nonsmoking participants with preschool children, incomes at or below the official US poverty level,
and space heating in their homes were recruited. The PAH concentrations were measured in the household indoor and
outdoor air, house dust, and yard soil, and in the diet of both an adult and a preschool child living in the home. An initial
study in two homes and an additional study of nine homes, four urban and five rural, during the heating season were
completed. The problems and successes encountered in the recruitment process and selected results of the heating season
measurements are summarized in this paper.
17.KEY WORDS AND DOCUMENT ANALYSIS
•.DESCRIPTORS
b.IDENTIFIERS/ OPEN ENDED
TERMS
c.COSATI



18. DISTRIBUTION STATEMENT
Release to public.
19. SECURITY CLASS (This Report)
Unclassified
21.NO. OF PAGES

20. SECURITY CLASS (This Page)
Unclassified
22. PRICE
-------