p. 1

EPA 747-R-99-002

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67p March 1999

LEAD EXPOSURE ASSOCIATED WITH RENOVATION

AND REMODELING ACTIVITIES : PHASE III

WISCONSIN CHILDHOOD BLOOD-LEAD STUD Y

Prepared by

BATTELLE

505 King Avenu e

Columbus, Ohio 43201-2693

for

Technical Branch

National Program Chemicals Division

Office of Pollution Prevention and Toxics

U .S . Environmental Protection Agency

Washington, D.C . 20460

/
p. 2

U .S . EPA DISCLAIME R

This report was prepared under contract to an agency of the United States

Government. Neither the United States Government nor any of its employees,

contractors, subcontractors, or their employees makes any warranty, expressed or

implied, or assumes any legal liability or responsibility for any third party use of or

the results of such use of any information, apparatus, product, or process disclosed

in this report, or represents that its use by such third party would not infringe on

privately owned rights.

Publication of the data in this document does not signify that the contents

necessarily reflect the joint or separate views and policies of each sponsoring agency . Mention of trade names or commercial products does not constitute endorsement or

recommendation for use .

BATTELLE DISCLAIMER

This is a report of research performed for the United States Government by

Battelle. Because of the uncertainties inherent in experimental or research work,

Battelle assumes no responsibility or liability for any consequences of use, misuse,

inability to use, or reliance upon the information contained herein, beyond any

express obligations embodied in the governing written agreement between Battelle

and the United States Government .

ii

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ACKNOWLEDGMENTS

Five institutions participated in designing and conducting the Wisconsin Childhood

Blood-Lead Study. The State of Wisconsin Bureau of Public Health, in cooperation with the

University of Wisconsin-Madison, conducted the retrospective study . Key personnel were

Dr. Marty Kanarek (Principal Investigator) and Tiffany Taha of the Department of Preventive

Medicine at the University of Wisconsin and Joe Schirmer of the State of Wisconsin . The

University of Wisconsin-Madison was responsible for human subjects approval, preparing the

database, and coordinating between the University and the State of Wisconsin . Dr. Kanarek

designed the study and questionnaire and provided overall guidance . Joe Schirmer developed the

initial questionnaire . Larry Hanrahan, Wisconsin Bureau of Public Health, helped design the

study; and Barbara Haley, U.S . Department of Housing and Urban Development, helped develop

the questionnaire.

Telephone interviews were conducted by the University of Wisconsin Extension Survey

Research Lab. Lead personnel were Nancy Davenport and Stig Nelson. The Survey Research

Lab was also responsible for quality assurance . Battelle assisted in designing the study and

questionnaire, conducted the data analysis, and prepared this report . Drs. Nancy McMillan and

Ron Menton were the key Battelle personnel involved .

The Environmental Protection Agency (EPA) funded the study through the University of

Wisconsin. Dan Reinhart was the key EPA contact . Battelle's efforts were funded by EPA

under Contract Number 68-D5-0008, Work Assignments 1-14, 2-14, 3-20, and 4-05 . Dan

Reinhart was the Work Assignment Manager.

This report benefitted significantly from comments and suggestions provided by four peer

reviewers. The reviewers were Mr. John Rogers (Westat) and Drs. Janie Gittleman (NIOSH),

Bruce Lanphear (Children's Hospital Medical Center), and Dori Reissman (CDC) .

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TABLE OF CONTENTS

Page

ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii

EXECUTIVE SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .vii

1 .0 INTRODUCTION AND BACKGROUND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

1 .1 PEER REVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

2 .0 STUDY DESIGN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2 .1 ELIGIBILITY REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2 .2 SAMPLE SELECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2 .3 QUESTIONNAIRE DESIGN AND IMPLEMENTATION . . . . . . . . . . . . . . . . . . . . . 6

2.4 STUDY LIMITATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

3.0 DATA SUMMARY AND STATISTICAL ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

3 .1 DATA SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

3 .1 .1 Available Blood-Lead Concentration Data . . . . . . . . . . . . . . . . . . . . . . . . 11

3 .1 .2 Characteristics of Sampled Children . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

3 .1 .3 R&R Exposure Characterization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 6

3 .2 DATA QUALITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

3 .2.1 Blood-Lead Registry and Interview Data . . . . . . . . . . . . . . . . . . . . . . . . . 25

3.2 .2 Assessment of Nonresponse and Selection Bias . . . . . . . . . . . . . . . . . . . . 26

3.2 .3 Assessment of Skin Contamination . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

3.3 STATISTICAL ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

3 .3 .1 Univariate Statistical Analyses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

3 .3 .2 Multivariate Statistical Analyses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

3 .3 .3 Statistical Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

4.0 CONCLUSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

5 .0 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

APPENDIX A: EXPLORATORY ANALYSIS OF WISCONSIN CHILDHOOD BLOOD-LEAD STUD Y

QUESTIONNAIRE DATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-1

APPENDIX B : LOGISTIC REGRESSION BACKGROUND . . . . . . . . . . . . . . . . . . . . . . . . . . . . B-1

APPENDIX C: TEST-WISE SIGNIFICANT RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C-1

APPENDIX D. UNIVARIATE REGRESSION OF CONSTRUCTED R&R VARIABLES . . . . . . . . . . . D-1

LIST OF TABLES

Table 2-1 . Sample Selection Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Table 2-2 . Summary of Questionnaire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Table 3-1 . Summary Statistics for Medical Assistance, Race, Gender, Method of Blood Draw ,

Date Samples Collected, and Age of Child . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Table 3-2 . R&R Activity Exposure Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

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Table 3-3a . Inside Painting Specific Exposure Summary . . . . . . . . . . . . . . . . . . . . . . . . . 20

Table 3-3b . Other Repairs (Windows) Specific Exposure Summary . . . . . . . . . . . . . . . . . . 21

Table 3-3c . Carpets and Floors (Repair or Replacement) Specific Exposure Summary . . . . . 22

Table 3-4. Summary of Demographic Information for Participants and Nonparticipants . . . 28

Table 3-5. Comparison of Participation Between Cases and Controls . . . . . . . . . . . . . . . . 30

Table 3-6 . Six Capillary Blood-Lead Concentration Measurements with Possible Ski n

Contamination Bias . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Table 3-7 . Assessment of Skin Contamination of Capillary Blood Samples for Six Ag e

Groups of Children . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Table 3-8. Significant (Based on the Holm Procedure) Univariate Odds Ratio Estimates

and Confidence Intervalse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Table 3-9. Variables Considered for the Baseline Logistic Regression Model . . . . . . . . . . . 38

Table 3-10. Odds Ratio Estimates and Confidence Intervals for Baseline Logistic Regressio n

Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Table 3-1 1 . Renovation and Remodeling Variables Used to Assess Relative Risk . . . . . . . . . 42

Table 3-12 . Unconditional Odds Ratios from Logistic Regression with Single R&R Variables . 44

Table 3-13 . Conditional Odds Ratios from Logistic Regressions with Single R&R Variable s

(and Any Other R&R Variables Nesting Them) . . . . . . . . . . . . . . . . . . . . . . . . 45

Table 3-14. Conditional Odds Ratios from Logistic Regression with Multiple R&R Variables . 47

Table 3-15 . Breakdown of Type of Specific R&R Activity by Type of Individual Wh o

Did Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

LIST OF FIGURES

Figure 3-1 . Trend Plot to Assess the Seasonality of Blood-Lead Concentrations in th e

Registry Database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Figure 3-2 . Odds Ratio Comparing Odds of an Elevated Blood-Lead Concentration for a

Child of Age Specified by the x-Axis to a 1-Year-Old Child's Odds . . . . . . . . . . 40

Figure 3-3. Odds Ratio Comparing Odds of an Elevated Blood-Lead Concentration for a

Child in a Household with Number of Residents Specified by the x-Axis to a

Child in a Household with Three Residents . . . . . . . . . . . . . . . . . . . . . . . . . . 40

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EXECUTIVE SUMMARY

Lead poisoning is considered a serious threat to health in the United States. Since the use

of lead in gasoline has been phased out, exposure to lead is now p rimarily from lead-based paint,'

particularly for children and construction workers. Federal programs unde rtaken to mitigate

exposure to lead-based paint have focused on dete riorated paint and methods of abatement . As a

result, the potential for exposure of workers and building occupants to lead resulting from

renovation and remodeling (R&R) conducted with no abatement intent has not been evaluated.

To address this potential, the United States Congress directed the U .S. Environmental

Protection Agency (EPA) to

• Determine the extent to which persons engaged in various types of residential R&R

activities are exposed to lead

• Determine the extent to which persons engaged in various types of R&R activities

disturb lead and create a lead-based paint hazard (on a regular or occasional basis) to

building occupants or other exposed individuals.

To meet these objectives, the EPA launched a se ries of studies in 1993 collectively

known as the R&R study . The first of these studies was the Environmental Field Sampling

Study (EFSS or Phase I). In this study, lead levels in settled dust and in breathing zone air

resulting from a variety of R&R activities (window replacement, sanding, paint preparation,

demolition, cutting painted wood, etc .) were measured. These lead measurements were assumed

to indicate the potential for lead exposure to construction workers and to building occup ants as a

result of R&R activities.

The second study, the Worker Characte rization and Blood-Lead Study (WCBS or

Phase II), examined the relationship between the blood-lead concentrations of construction

workers and their R&R activities, work habits, medical histo ries, hobbies, etc.

In general, the results of Phases I and II indicated that, for some R&R activities, airborne

lead levels within workers' breathing zones often exceeded the Occupational Safety and Health

Administration's permissible exposure limit, but the blood-lead concentrations of workers that

regularly engage in these activities were not likely to be elevated (z 10 ,ug/dL). The implications

for building occupants (especially children), however, were not as clear . The potential for

exposure to occupants was characte rized in the EFSS (Phase I) by measuring lead levels in dust

that was generated by various R&R activities. The results of Phase I indicated that most R&R

activities have a potential to disturb substantial amounts of lead and that occupants could be

exposed to lead if appropriate containment and cleanup precautions are not employed . However,

much uncertainty remained conce rning the extent to which this potential for lead exposure

translated to an actual internal dose for occupants (especially children).

Because children represent the population that is most likely to be sensitive to lead

exposure from R&R activities, it became imperative that the EPA acquire additional data to

assess the impact of residential R&R on children . Therefore, a third study, the Wisconsin

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Childhood Blood-Lead Study was conducted to determine the impact of residential R&R on the

blood-lead concentrations of children occupying the residences.

The Wisconsin Childhood Blood-Lead Study (Phase III) was a retrospective case-control

study designed to systematically examine the association between R&R activities and elevated

blood-lead (EBL) levels (z 10 μg/dL) among children . The primary objective of the study was to

compare the incidence of R&R activities in the residences of children with EBLs to R&R

activities in the residences of children without EBLs. Another objective of the study was to

determine if specific R&R activities were more prevalent in households with an EBL child than

in households with a non-EBL child . The study targeted children under the age of six who were

included in the Wisconsin Bureau of Public Health's blood-lead registry . These children resided

in communities other than Milwaukee and Racine and were screened between March 1996 and

December 1996 .

To meet these objectives, telephone interviews were conducted with the parents or

guardians of 3,654 children under the age of six about R&R activities in their residences .

Responses during the telephone interview, as well as the child's blood-lead concentration as

recorded in the Wisconsin Bureau of Public Health's blood-lead registry, were used to assess

whether R&R, in general, increases a child's risk of having an elevated blood-lead concentration .

The telephone questionnaire and blood-lead information were also used to determine if specific

R&R activities were associated with an increased risk of an elevated blood-lead concentration .

The questionnaire was designed to determine whether R&R activities such as inside

painting, outside painting, carpet and floor repair or replacement, and other repairs (such as

window repair) were conducted in the residences of the children in the study . Although it is

difficult to generalize the information beyond the study population, the frequency of general and

specific R&R activities in residences populated by young children is a valuable product of this

study. While the main objective of this study was to investigate the relationship between

incidences of R&R activities and EBL children, a dose-response type relationship, this

information is most useful when the degree of exposure is also known . In this case, if a slight

increase in risk due to childhood lead exposure as a result of R&R activity is detected, the

implications are best considered in light of the numbers of children likely to be exposed.

Analysis of the exposure data related to these activities revealed that at least one R&R

activity had been conducted in 67 .2 percent of the residences in the previous 12 months. Inside

painting occurred in 50 percent of residences and outside painting, carpet and floor repair or

replacement, or other repairs occurred in 20 percent. Some form of surface preparation was

involved in 42.3 percent of R&R activities. Approximately 65 percent of the outside painting

involved surface preparation, compared to 15 percent to 30 percent for each of the other types of

activities. Most surface preparation involved hand scraping or sanding . Heat guns were used

7 percent of the time, and chemical paint removers were used 13.6 percent of the time. Surface

preparation for painting was usually performed by the owner of the residence, the building

superintendent, or apartment staff, while preparation for carpet and floor repair or replacement or

other repairs was usually performed by paid professional contractors.

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Univariate and multivariate logistic regression models developed from the questionnair e

and blood-lead data collected for this study were used t o

1 . Determine if the incidence of R&R in residences was associated with an increased

risk of an EBL (z 10 μg/dL).

2. Determine ifspecific R&R activities were associated with an increased risk of a child

having an EBL.

The study demonstrated that residential R&R is associated with an increased risk of an

EBL in children. The study also demonstrated that specific R&R activities are associated with

an increase in the risk of an EBL in children . In particular, painting inside or outside, removing

paint (using open flame torch, using heat guns, using chemical paint removers, and we t

scraping\sanding), preparing surfaces by sanding or scraping, and living in a home when R&R

work was done significantly increased the risk of EBLs . An EBL was more likely when a

relative or friend not living in the household did the R&R work . In addition, the more rooms

involved in the total R&R project, the more likely a child was to have an EBL . Any type of

R&R work in the kitchen increased the odds of an EBL.

Overall, these results agree with those from earlier phases of the R&R Study - R&R

activities that disturb lead-based paint increase the risk of exposure to occupants . For example,

children living in a residence while R&R was conducted were 1 .3 times more likely to have

EBLs than children who did not live in a residence while R&R was conducted .

Further, the study has identified specific R&R activities and other conditions (such as age

and type of residence) that are associated with increased risk to children as a result of lead

exposure . This information can be used to develop regulations that focus on particular R&R

activities (e .g., using a heat gun to remove paint), groups of persons (e .g., a household member

other than the head of household or spouse) who perform the activities, and the other conditions

(e.g., adult exposure, age of child) that significantly increase the risk to children. The results of

this study concerning activities associated with increased risk (e.g., using a heat gun to remove

paint) also can be combined with the worker profile results from Phase II to perform an overall

assessment of the worker groups or situations where interventions are needed to reduce exposure

from R&R.

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1 .0 INTRODUCTION AND BACKGROUN D

Lead poisoning is considered a serious threat to health in the United States. Since the use

of lead in gasoline has been phased out, exposure to lead is now primarily from lead-based paint

(CDC, 1991) . To address the potential for this type of exposure, in 1992, the United State s

Congress enacted the Residential Lead-Based Paint Hazard Reduction Act (Public Law

102-550), which required the U .S. Environmental Protection Agency (EPA) to conduct a study of

lead exposure associated with renovation and remodeling activities (R&R study). In particular,

paragraph (2) of Section 402(c) states:

The Administrator shall conduct a study of the extent to which persons engaged in

various types of renovation and remodeling activities in target housing, public buildings

constructed before 1978, and commercial buildings are exposed to lead in the conduct of

such activities or disturb lead and create a lead-based paint hazard on a regular or

occasional basis.

The overall objectives of the R&R study were t o

• Determine the extent to which persons engaged in various types of residential R&R

activities are exposed to lead

• Determine the extent to which persons engaged in various types of R&R activities

disturb lead and create a lead-based paint hazard (on a regular or occasional basis) to

building occupants or other exposed individuals .

To meet these objectives, a series of studies, known collectively as the R&R Study, was

launched in 1993 by EPA :

• Phase I: The Environmental Field Sampling Study (EFSS) . The EFSS was

conducted to measure the airborne lead levels and lead levels in settled dust resulting

from R&R activities (EPA, 1997a, and EPA, 1997b) .

• Phase II: The Worker Characterization and Blood-Lead Study (WCBS) . The WCBS

was designed to collect questionnaire and blood-lead data that could be used to assess

the relationship between R&R activities and lead exposure for the R&R workers

conducting these activities (EPA, 1997a, and EPA, 1997c).

In Phase I, lead levels in settled dust and in breathing zone air that resulted from a variety

of R&R activities (window replacement, sanding, paint preparation, demolition, cutting painted

wood, etc.) were measured . These environmental lead measurements were assumed to indicate

the potential for lead exposure to R&R workers and to building occupants resulting from R&R

activities. In Phase II, the relationship between blood-lead levels among R&R workers and

variables such as their work activities, work habits, medical histories, and hobbies, was

examined.

1

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In general, Phases I and II indicated that, for some R&R activities, airborne lead levels

within workers' breathing zones often exceeded the Occupational Safety and Healt h

Administration's permissible exposure limit, but worker blood-lead concentrations were not

likely to be elevated. The implications for building occupants (especially children), however,

were not as clear. The potential for exposure to occupants was characterized in Phase I by

measuring lead levels in settled dust that was generated or released by various R&R activities .

Phase I indicated that most R&R activities have the potential to disturb substantial amounts of

lead to which occupants could be exposed if appropriate containment and cleanup precautions

were not employed. However, much uncertainty remained concerning the extent to which this

potential for lead exposure translated to an actual internal dose for occupants (especially

children).

Because children represent the population that is most likely to be sensitive to lead

exposure from R&R activities, it became imperative that the EPA acquire additional data to

assess the impact of residential R&R on children . Therefore, a third study, the Wisconsin

Childhood Blood-Lead Study was conducted to determine the impact of residential R&R on the

blood-lead concentrations of children occupying the residences .

The Wisconsin Childhood Blood-Lead Study (Phase III) was designed to systematically

examine the association between R&R activities and elevated blood-lead levels (EB L

z 10 μg/dL) among children . To overcome the major obstacles associated with collecting

children's blood samples for a prospective study (problems with human subjects approval,

parental permission, low participation rates, etc .), Phase III used the Wisconsin Bureau of Public

Health's registry of children's blood-lead measurements.

The primary objective of the study was to compare the incidence of R&R activities in the

residences of children with an EBL to incidence of R&R activities in the residences of those

without an EBL. Furthermore, the study was designed to determine if specific R&R activities

were more prevalent in residences of EBL children than in residences of children who did not

have EBLs. To meet these objectives, telephone interviews were conducted with the parents or

guardians of 3,654 EBL and non-EBL children about R&R activities in their residences. The

study targeted children under the age of six who resided in communities other than Milwaukee

and Racine and whose blood-lead concentrations were screened between March 1996 and

December 1996 .

1 .1 PEER REVIEW

This report has benefitted significantly from comments and suggestions provided by four

external peer reviewers. Each of the reviewers recommended publishing the report after minor

revisions. Comments which had a significant impact on the report or which aid in interpreting

the study results are discussed below .

In response to comments by a number of the reviewers, more details regarding the study

design were provided. In particular, certain design decisions which placed limitations on the

study results were emphasized . Because recall bias was a concern for several reviewers a table

was added (Table 2-1) to summarize time delays between blood sampling and administration of

2
p. 13

the questionnaire. The questionnaire used in this study was designed to facilitate recall, and

therefore, minimize recall bias.

The requirement that all study participants have known medical assist ance status is a

limitation of this study that was noted by multiple reviewers . Prior to performing the study, it

was hypothesized that the impact of R&R activities on EBLs may be different between the two

medical assist ance populations. If this hypothesis were true, separating these two populations

would have been instrumental in determining the relationship between R&R activities and EBLs.

Since the Wisconsin registry did not contain numbers of medical assistance and non-medical

assistance children typical of Wisconsin in general, representativeness of the study data with

respect to medical assistance status was not affected by this decision . The effect ofmedical

assistance status on incidence of EBLs was accounted for by incorporation of the medical

assistance status variable in a baseline model of EBL incidence prior to consideration of the

effect of R&R activities. Thus, study results are believed to be applicable to both medical

assistance and non-medical assistance populations . However, the limitation inherent in the

decision to only include children with known medical assist ance status is that a large number of

children, possibly m any with EBLs, were excluded from the study.

At the request of several reviewers, more detail on the Wisconsin blood-lead regist ry was

provided. In particular, quality control during blood sample collection and analysis was an issue

for the reviewers. Quality control of analysis is regulated by CLIA, the clinical laboratory

improvement amendments of 1988. However, quality control of the sample collection is up to

the sample collector. Several Wisconsin state organizations work with sample collectors to

inform them of quality control issues that may a rise.

In regard to the Wisconsin blood-lead registry, another issue of concern among the

reviewers was how representative the registry is of the state population. A comparison of the

racial distribution across the state (excluding Milwaukee and Racine counties) to the racial

distribution selected for this study revealed that minorities are likely over represented in the

registry. This finding does not limit the main study conclusions as exact representativeness of

the data with respect to an explanatory variable is not essential for determination of the

relationship between another explanatory variable (R&R activities) and a response (incidence of

EBL).

Based on the comments of one reviewer, a new multiva riate analysis of the study data

was added to the report. This analysis demonstrates the impact of simult aneously considering

many R&R activities to determine those most associated with increased odds of an EBL. Results

from this analysis were very consistent with analyses considering R&R activities individually .

At least one reviewer was conce rned that there appeared to be no difference in risk

between R&R activities performed in pre- and post-1980 homes. Additional discussion of the

statistical analysis used to determine this finding was added to the repo rt to allay this concern.

There are many possible reasons for this finding, including :

1 . Age of residence was an interview reported variable, and, thus, may have been

reported inaccurately for some homes .

3

13
p. 14

2. Only the manufacturing of lead-based paint was banned in 1978 . Residences may

have been painted with old lead-based paint .

3 . R&R activities in residences may increase risk due to childhood lead exposure by

stirring up lead contaminated dust from sources other than lead-based paint .

EPA has established a public record for the peer review under administrative record

AR-209. The record is available in the TSCA Nonconfidential Information Center, which is

open from noon to 4 PM Monday through Friday, except legal holidays . The TSCA

Nonconfidential Information Center is located in Room NE-B607, Northeast Mall,

401 M Street SW, Washington, D .C.

4

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p. 15

2 .0 STUDY DESIG N

The Wisconsin Childhood Blood-Lead Study was a retrospective case-control study of

the association between EBLs in children and the incidence of R&R activities in their residences.

Blood-lead concentration data were obtained from screening data recorded in the Wisconsin

Bureau of Public Health's blood-lead registry . A subset of children were selected from the

registry for participation in the study based on several eligibility requirements (Section 2 .1) . All

eligible children with a blood-lead concentration greater than or equal to 7 μg/dL were selected

into the study. Random selection was used to select among the eligible children with blood-lead

concentrations less than 7 μg/dL . Sample selection (Section 2 .2) was a sequential process

consisting of separate samples drawn monthly from screening data compiled between the months

of March and December 1996 . Information on R&R activities in participating children's

residences was obtained by administering a questionnaire (Section 2 .3) over the telephone . To

the extent feasible, this study collected interview data as soon as possible once each month's

blood screening data was available in the registry.

2 .1 ELIGIBILITY REQUIREMENTS

The sampling frame consisted of children under the age of six who were screened for

blood-lead concentrations from March 1996 to December 1996. Only one child per household

was eligible for the study. All eligible children with a blood-lead concentration greater than or

equal to 7 μg/dL were selected into the study . Random selection was used to select among the

eligible children with blood-lead concentrations less than 7 μg/dL .

All the children selected were from communities outside Milwaukee and Racine .

Children from these cities were omitted for two reasons . First, these cities have a higher

incidence of lead poisoning compared to the state as a whole . This higher incidence of lead

poisoning may be a result of a greater density of older, deteriorated housing, which would make

it more difficult to isolate the effect of lead exposure from renovation activities on the children.

Second, the health departments in these communities manage their data independently, which

would have resulted in delays in contacting the families directly . In designing the study, it was

hoped that the possibility of finding an effect on blood-lead concentrations resulting from R&R

would be maximized by studying a large, non-inner city population .

In Wisconsin, blood-lead screening is mandatory for children receiving medical

assistance (Medicaid) and voluntary for others. As a result, the proportion of families receiving

medical assistance in the Wisconsin blood-lead registry may be higher than the proportion of

such families in the state . Therefore, separate sampling frames were constructed for families on

medical assistance and for families not on medical assistance. Known medical assistance status

was required for inclusion of a child into the study.

2 .2 SAMPLE SELECTIO N

Using screening data collected from March 1996 to December "1996, a sample was drawn

from the Wisconsin blood-lead registry for each month. Monthly samples were selected

approximately sequentially ; i .e., the May sample was selected before the June sample. (Because

5

6
p. 16

sample sizes achieved each month were smaller than anticipated, samples for the months o f

March and April were added to the study after the May and June samples were completed .) The

sampling frame for each month contained all eligible children whose first blood-lead sample was

collected in that month, and who did not have another household member already included in the

study. When first blood-lead data were collected during the same month for more than one child

in the same family, one child was randomly selected to be eligible for the study .

Initially, 100 percent sampling was conducted for cases (children with a blood-lead

concentration greater than or equal to 10 μg/dL), and a random sample was drawn from the

controls (children with a blood-lead concentration less than 10 μg/dL) . For each sampling frame ,

however, the number of children with an EBL was smaller than expected . Therefore, the number

of cases selected, even with complete sampling, was smaller than anticipated . To compensate for

this, the study design was modified prior to selecting the August sample to include 100 percent

sampling for children with a blood-lead concentration between 7 and 10 μg/dL . Thus, before the

August sample was collected eligible children from the months of March through July with

blood-lead concentrations between 7 and 10 μg/dL were added to the study.

Random selection of children with blood-lead concentration less than 7 μg/dL was

performed separately for medical assistance and non-medical assistance children . Monthly

samples for March though September targeted 450 children with blood-lead concentration less

than 10 μg/dL from each group . Monthly samples for October through December targeted

250 children with blood-lead concentration less than 7 μg/dL from each group. Some months,

one of the groups did not have enough children to meet the target . For that group, 100 percent

sampling was performed.

Table 2-1 provides information regarding the monthly samples selected for this study . In

Table 2-1 the month that each sample was selected is noted . To minimize the time between

blood sampling and interview data collection, the sample drawn for each month was immediately

sent to Survey Research Labs to begin telephone interviewing . On average, there was a 4-month

delay between blood screening and administration of the questionnaire . In general, the lag time

was smaller toward the end of the study . The change in numbers of low blood-lead

concentration children targeted in the monthly sampling that occurred between September and

October can be clearly seen in Table 2-1 .

2 .3 QUESTIONNAIRE DESIGN AND IMPLEMENTATIO N

The limited resources available to conduct this study in an area as geographically diverse

as the State of Wisconsin precluded in-person interviews as a method for obtaining the

questionnaire information . Further, to obtain information quickly (thus reducing the potential for

recall bias), and to increase the participation rate, a telephone interview approach was adopted

rather than a mail questionnaire. (Groves et al., 1988, discusses the advantages and

disadvantages of telephone survey methods .)

6&
p. 17

Table 2-1 . Sample Selection Summa ry

Number of Children Selected

Sample Children

Month Selection Date Eligible PbB<7 Ng/dL 7 Ng/dLsPbB<10 Ng/dL PbB2: 10 pg/dL

May September 1996 1458 855 134 85

June September 1996 1328 767 75 71

April October 1996 1286 709 104 92

March October 1996 1153 686 93 76

July October 1996 1528 805 120 121

August January 1997 1499 843 132 113

September January 1997 1405 745 114 79

October January 1997 1240 493 91 61

November February 1997 1005 486 66 64

December February 1997 914 474 63 41

With any survey requesting information on events that occurred in the past, one potential

for bias is due to the inherent difficulty of recalling past activities. Activities conducted in the

recent past are more easily recalled than activities conducted in the more distant past. Therefore,

delays between blood-lead sampling and administering the questionnaire could bias results

(i.e., R&R activities occurring further in the past may not be "remembered" or participants may

provide less reliable information) . As noted in the previous section, the time delay between

blood-lead sampling and questionnaire administration was, on average, four months . The

questionnaires used in this study were designed to facilitate recall and, therefore, minimize this

source of bias. For example, in addition to asking participants when and for how long (hours or

days) they performed an activity, the participants were also simply asked whether or not they

performed that activity (easier questions to recall and therefore less prone to recall bias) .

An attempt was made to contact by telephone the parent or guardian of each child

selected for the study . Because phone numbers and addresses were missing for some children, it

was not possible to contact a parent or guardian for each selected child. If the parent or guardian

was contacted, a telephone questionnaire (see Appendix A) was administered . The telephone

interview collected data on, among other things, specific R&R activities that may have been

related to the child's blood-lead concentration . Table 2-2 summarizes the type of information

elicited by the questionnaire.

The questionnaire was pretested using 13 respondents . The interviews average d

13 .4 minutes. As a result of the pretest, questions about the occupations and hobbies of adults in

the household, eating habits, painting preparations, and painting done inside the home were

added to the questionnaire, which was tested on an additional 32 people . Obtaining this

additional information added an average of 4.6 minutes to the interview.

7/7
p. 18

Most of the respondents in the study were interviewed in English ; but, because a

substantial number of Hmong and Spanish families were expected in the sample, the interview

was translated into Hmong and Spanish to ensure consistent questioning. Interviews were

conducted in Hmong with 103 families, or 2.8 percent of the interviewees, in Spanish with 44, or

1 .2 percent of the interviewees, and in English with 3,508, or 96 .0 percent of the interviewees.

Table 2-2. Summary of Questionnaire

Type of Information Rational e

Child's Residence Includes questions on age of dwelling, if buying or renting, and

presence of peeling paint . This information may be related to child's

blood-lead concentration .

Duration of Residence Includes questions on whether child lived in current home longer than

12 months . This information was used to ensure that information

regarding child's residence (i .e ., age of residence) was accurate at

time of blood collection .

R&R Activities Includes questions about the conduct of specific R&R activities in the

past 12 months, such as how was the work done, who did it, and

where it was done . Targeted activities were interior painting, exterior

painting, window repair, carpet removal, and wall repair .

Blood Sampling Includes questions on how many and why blood samples were taken. This information was used to help ensure that blood-lead

concentration was not reduced due to medical treatment .

Household Information Includes questions on number of household residents, education

attained by parent or guardian, and family dining habits. This

information may be related to lead exposures .

Adult Occupations Includes questions about occupations that may be confounded with

lead exposures in the household.

Hobbies Includes questions about hobbies that may be confounded with lead

exposures in the household .

Income and Address Includes questions on income and child's address . Income and

11 1 neighborhood may be associated with child's blood-lead concentration .

2.4 STUDY LIMITATIONS

As with all studies, there are limitations associated with study design decisions . Limitations of this study include

1 . Restriction to only registry children with known medical assistance status

2. Differential selection probabilities among the low blood-lead concentration children

(<7 μg/dL) across the study months

3 . Exclusion of Milwaukee and Racine childre n

4. Recall bias due to the time delay between blood-lead sampling and questionnaire

administration

5. Exclusion of possible confounding variables from the questionnaire.

8

/U
P. 19

Each of the above limitations is due to the inevitable trade-off between the practical issue s

associated with implementing a study and the desire to obtain the best data possible.

The study was restricted to include only children with known medical assistance status

because, prior to performing the study, it was hypothesized that the impact of R&R activities on

EBLs may be different between the two medical assistance populations . If this hypothesis were

true, separating these two populations would have been instrumental in determining th e

relationship between R&R activities and EBLs. Since the Wisconsin registry did not contain

numbers of medical assistance and non-medical assistance children typical of Wisconsin in

general (screening of medical assistance children is mandatory), representativeness of the study

data with respect to medical assistance status was not affected by this decision . However, the

limitation inherent in the decision to only include children with known medical assistance status

is that a large number of children, possibly many with EBLs, were excluded from the study.

Differential selection probabilities among the low blood-lead concentration children

(<7 μg/dL) across the study months adversely affects the ability to detect seasonality effects in

the data. While this limitation is unfortunate, interviewing low blood-lead concentration children

during the last months of the study was restricted to boost the number of EBLs in the study .

Having only a small percentage of the study children in the elevated group reduces the power to

detect the effect of R&R activities on the incidence of EBLs .

Exclusion of Milwaukee and Racine children from the study has the unfortunate side

effect of reducing the number of EBL children eligible for the study. However, a number of

practical concerns, as discussed in Section 2 .1, dictated this decision.

As with any survey requesting information on events that occurred in the past, one

potential for bias in the relationship between the conduct of R&R activities and children's

blood-lead levels is due to inherent difficulties associated with recalling activities that occurred

in the past. This limitation is described in Section 2.3.

The extensive telephone interview employed in this study required about 18 minutes per

interview. A variety of information (adult occupations, hobbies, household information) was

solicited during this interview in addition to the R&R activity data. However, other variables

that affect the relationship between R&R activities and incidence of EBLs may not have been

obtained. Possible candidates include use of traditional medicines or use of ceramics in cooking

and serving food. These variables are particularly important among the Hmong and Spanish

households surveyed.

In spite of the above limitations, this study provides valuable data for estimating the

effect of R&R activities on the incidence of EBLs among a diverse population of children.

9

Iq
p. 20

3 .0 DATA SUMMARY AND STATISTICAL ANALYSIS

This study evaluated the impact of residential R&R on children's blood-lead

concentrations by comparing the incidence of R&R activities in residences with an EBL child to

R&R in residences with a non-EBL child. Specifically, analyses were conducted to

• Determine if the incidence of R&R activities in residences was associated with an

increased risk of an EBL

• Determine ifspecific R&R activities were associated with an increased risk of a child

having an EBL.

Based on the data collected, exposure of residents to R&R activities in study homes was also

characterized. This information provides an assessment of the portion of residences affected by

hazards due to R&R activities . This chapter contains a discussion of the data collected and

characterization of exposure to R&R activities (Section 3 .1), the potential problems with the data

(Section 3 .2), and the analysis of the data to determine the impact of R&R on the probability of

an elevated blood-lead concentration in children (Section 3 .3). '

The data, summarized in Section 3 .1, includes information on 8,651 Wisconsin children

residing outside of Milwaukee and Racine whose first blood-lead concentration measurement

was collected (and recorded in the Wisconsin Bureau of Public Health's blood-lead registry)

between March and December of 1996 . Interview data was collected for approximatel y

42 percent (3,654) of these children and is reported in Section 3 .1 .

A number of data quality concerns, specifically quality control procedures used during

the collection of blood-lead registry and interview data, are discussed (Section 3 .2.1). Because

nonresponse and sampling bias are of considerable concern when interview data are collected,

nonresponse and sampling bias are also discussed (Section 3 .2.2). Skin contamination was a

concern in this study because the Wisconsin blood-lead registry consists primarily of

measurements collected by the capillary method . Confirmatory venous blood-lead

measurements (taken when a child's first blood-lead measurement is very high) indicated the

possibility of skin contamination for four samples (Section 3 .2 .3) .

Data collected in this study were analyzed using logistic regression, a statistical method

used to explain the relationship between a dichotomous (yes/no) response variable and a suite of

explanatory variables (McCullagh and Nelder, 1989). A number of social and demographic

variables are known to be associated with elevated blood-lead concentrations (Bornschein et al

.,

1985 ; Brody et al., 1994; and Lanphear et al., 1996). Analysis were conducted to examine the

impact of these variables prior to considering the effects due to R&R . A baseline logistic

regression model was developed to explain the odds of an elevated blood-lead concentration as a

function of such social and demographic variables as the child's age, the age of the residence ,

Elevated blood-lead concentrations are defined as >_ 10 μg/dL (CDC, 1994) and nonelevated blood-lead

concentrations as less than 7 μg/dL.

10
p. 21

and family income. R&R variables were then entered into this model and their statistica l

significance assessed . Conclusions on the magnitude and significance of particular R&R

variables, calculated in this manner, are found in Section 3 .3.2. Appendix B provides

background information on logistic regression, including an explanation of why this method was

used to analyze data from this study. 2

3.1 DATA SUMMARY

Between March and December of 1996, the first blood-lead concentration measurements

of approximately 50,000 children residing outside of Milwaukee and Racine were recorded in the

Wisconsin Bureau of Public Health's blood-lead registry . Multiple blood-lead measurements

were reported for some of these children, generally as confirmatory measurements when the first

measurement was elevated . (See CDC, 1991, for childhood blood-lead screening

recommendations.) A total of 8,651 of these children were selected to participate in this study .

Interviews were conducted for 3,654 of the 8,651 children. Four children who were interviewed

had blood-lead concentrations that were believed to be mistaken and were dropped from the

study (see Section 3 .2 .3).

This study consists of data on the remaining 3,650 children . Some analyses presented in

this report used the larger database consisting of all 8,651 children selected to the study. This

larger database is referred to as the registry database . Analyses based on the registry database are

clearly indicated.

3 .1 .1 Available Blood-Lead Concentration Dat a

The Wisconsin blood-lead registry contained data on the following variables:

• Medical assistance status (Medicaid)

• Race

• Gender

• Blood sample collection technique

• Month that first blood-lead sample was collected

• Age

• Blood-lead group (number of low, medium, and high observations)

• Blood-lead concentration.

The first nine and the last columns of Table 3-1 present a summary of the data available for each

of these variables. Appendix A shows similar descriptive statistics for data resulting from the

interview responses. In addition to counts of children by levels of demographic variables and

blood-lead group, geometric means and geometric standard deviations are calculated by levels of

demographic variables.

2 Since the individual observations were selected into the study based on blood-lead concentration, using

blood-lead concentration as a response variable was not appropriate . Logistic regression of the

categorical high/low blood-lead group variable is the appropriate analytical procedure .

11
p. 22

Table 3-1 . Summary Statistics for Medical Assistance, Race, Gender, Method of Blood

Draw, Date Samples Collected, and Age of Child

Number of Observations for

Low (Pb8<7 μg/dL),

Medium (7sPbB<10 uy/dL),

and High (PbBz10 μpldL)

Blood-Lead Concentration

(n = 3650) Blood-Lead Concentration Log Odds Difference'

Geometric Standard

Geometric Mean Deviation Percent of

Obs . With Response Low Medium Hiph Confidence Confidence Standard Censored Catego ry (n = 2999) (n = 366) ( n = 285) Estlmate Interval' Estimate Interval' Estimate Error P-Value Blood-Lead

Medical Medical 1127 113 113 2.62 (2.40,2 .85) 2.60 (2.41,2 .t10) 67.8% Assistance Assistance

Other 1872 253 172 2.41 (2.24,2 .59) 2.66 (2.50,2.83) -0.09 0.13 0.4910 70.7%

Race Caucasian 2368 276 203 2.43 (2.28,2 .59) 2.63 (2.49,2.78) 70.5%

African 56 10 12 3.36 (2.48,4 .55) 2.62 (1.99,3.46) 0.92' 0.33 0.0050 59.0% America n

Asian 121 19 29 3.14 (2.47,3.99) 3.00 (2.41,3.73) 1.03' 0.22 0.0001 60.4%

Native 49 2 3 2.22 (1.37,3.60) 2.22 (1 .50,3 .28) -0.34 0.60 0.5743 77.8%

America n

Unknown 405 59 38 2.67 (2.34,3.06) 2.43 (2.15,2 .73) 0.09 0.18 0.6250 68.9%

Gender Male 1506 181 170 2.51 (2.32,2.71) 2.73 (2.55,2 .93) 68.8%

Female 1481 183 114 2.47 (2.29,2 .67) 2.53 (2.36,2 .70) -0.38' 0.13 0.0025 70.6%

Unknown 12 2 1 3.51 (2.19.5 .61) 1.90 (1.24,2 .93) -0.30 1.04 0.7713 60.0 %

Blood Venous 2901 355 275 2.50 (2.36,2 .64) 2.63 (2.50,2 .76) -0.07 0.34 0.8274 69.6% Sample

Collection Capillary 98 11 10 2 Techniqu e

.22 (1 .56,3 .17) 2.91 (2.15,3.95) 71.4%

Month Blood March 337 34 28 2.77 (2.41,3 .19) 2.40 (2.11,2.71) 0.13 0.63 0.8400 66.9%

Collected April 346 49 46 2.81 (2.42,3 .26) 2.83 (2.47,3.24) 0.60 0.62 0.3342 63.9%

May 427 57 33 2.60 (2.27,2 .97) 2.44 (2.17,2.75) 0.05 0.62 0.9303 69.4%

June 362 27 26 2.03 (1.66,2.48) 2.63 (2.23,3.10) -0.02 0.63 0.9765 76.4%

July 414 54 55 2.76 (2.41,3.16) 2.69 (2.38,3.04) 0.60 0.62 0.3322 65.8%

August 403 49 36 2.23 (1.87,2.65) 2.75 (2.37,3 .19) 0.20 0.62 0.7487 72.7%

September 365 45 26 2.27 (1 .91,2.71) 2.61 (2.25,3 .03) -0.03 0.63 0.9661 73.2%

October 239 37 24 2.47 (2.03,3.01) 2.66 (2.24,3 .16) 0.32 0.64 0.6183 70.0 %

November 65 3 8 2 .49 (1 .72,3.61) 2.46 (1.78,3 .39) 0.52 0.71 0.4612 71 .1%

December 41 11 3 3.18 (2.31,4 .37) 2.18 (1.63,2 .92) 63.6%

Age Less than 1 yr 362 29 31 2.01 (1 .64,2 .47) 2.81 (2.37,3 .34) -0.23 0.21 0.2949 75.4%

1 year old 923 131 99 2.76 (2.52,3 .02) 2.61 (2.41,2.82) 66.0%

2-year old 435 48 51 2.62 (2.28,3 .01) 2.64 (2.34,2.99) 0.09 0.18 0.6247 67.6%

3-yearold 418 69 46 2.90 (2.56,3 .27) 2.47 (2.21,2.75) 0.03 0.19 0.8914 65.1%

4-year old 420 44 38 2.40 (2.05,2 .79) 2.59 (2.27,2 .96) -0.17 0.20 0.3942 71.3%

5 -year old 424 44 19 1.91 (1.56,2.33) 2.67 (2.27,3 .14) -0.87' 0.26 0.0007 78.0%

6-yearold 17 1 1 0.54 (0.02,12.2) 5.07 (0.64,40 .0) -0.60 1.03 0.5614 89.5%

Note: Shaded cells (and asterisk) indicate statistically significant results .

' The log odds difference compares the odds (and hence the risk) of a child having an EBL concentration

between one category and a reference category within each variable . The reference groups in the table are

the row with blanks in the log odds difference column . For example, the reference group for "Age" i s

"1 year old" . A negative log odds difference indicates that the category has lower risk than the reference

category, and vice versa for positive log odds difference . For example, a log odds difference of -0.87

indicates that 5-year olds have significantly lower risk than 1 year olds . See Appendix B for more details on

log odds differences.

Z The confidence intervals for the geometric mean and geometric standard deviations are calculated by

constructing the approximate confidence interval ( t 2 standard errors) for the logarithm of each statistic and

then taking the exponential of the confidence bounds .

12
p. 23

Geometric means and standard deviations are often used instead of their arithmeti c

counterparts when the data are known to have positive values and the upper limit of the values is

unknown. The data in such cases are often assumed to follow a lognormal distribution, and the

geometric mean and standard deviation are natural parameters for describing the distribution (in

the same way the arithmetic mean and standard deviation are natural parameters for describing

the normal (Gaussian) distribution) . The use of the geometric measures to describe the

distribution of blood-lead concentrations is common in the literature (e .g., Brody et a1 .,1994).

The geometric means and geometric standard deviations of blood-lead concentration

reported in Table 3-1 (and Appendix A) were calculated using censored data techniques.

Censored data techniques are useful when, for some observations, exact values are not reported .

For example, when chemically analyzing a sample for some substance present only in trace

amounts, the reported result can be less than the limit of detection (LOD) . Thus, the only real

information obtained from the analysis is that the value is less than the LOD. Such a data point

is referred to as left censored . A right censored data point is one for which all that is known is

that data point is above some value. Using censored data techniques allows inexactly reported

data (i.e., values only known to be in some interval) to be appropriately considered .

According to the Wisconsin Bureau of Public Health, for many of the laboratories

reporting blood-lead measurements to the state registry, 4 μg/dL is the limit of detection for

blood-lead concentrations. Therefore, no blood-lead concentrations less than 4 μg/dL are in the

registry, and blood-lead concentrations reported as 4 μg/dL were assumed to be some value less

than or equal to 4 μg/dl, (left censored at 4 μg/dL) . The distribution of blood-lead

concentrations was assumed to be lognormal, and the method of maximum likelihood was used

to estimate the geometric means and geometric standard deviations . The assumption of

lognormality can be a limitation of the censored data approach. However, a lognormal

distribution has been extensively shown to be reasonable for blood-lead concentrations. Use of

censored data techniques was critical because, the percent of blood-lead concentrations that were

censored, listed in the last column of Table 3-1, generally is somewhere between 60 percent and

80 percent, except for cases when the number of observed blood-lead concentrations in the

category is low (e .g., when "Age" = "6 years old") .

Six blood-lead concentration measurements in the study database were greater than

40 μg/dL. (Eleven additional children in the registry database had first blood-lead

concentrations >40 μg/dL .) All these samples were collected using the capillary technique,

which can result in erroneous blood-lead measurements because of skin contamination

(CDC, 1991). Follow-up measurements for each of the six children in the study database

indicated that two had elevated blood-lead concentrations and four did not. The two

observations for which follow-up blood-lead measurements indicated an elevated blood-lead

concentration were treated as right censored at 40 μg/dL for estimating of the geometric means

and geometric standard deviations. The four children for whom subsequent blood-lead

measurements were <10 μg/dL were deleted from the study database . This is discussed in more

detail in Section 3 .2.3 .

Geometric means and geometric standard deviations of blood-lead concentration based

on data derived from this study should be considered with care . Because this study was a

1~3
p. 24

retrospective study (children were differentially selected for the study based on their blood-lead

concentrations), these values do not characterize blood-lead concentrations in Wisconsin or even

in the registry. Every child from the Wisconsin blood-lead registry with an elevated blood-lead

concentration was a candidate for the study, while only a fraction of the children with blood-lead

concentrations <7 μg/dL were included . Thus, geometric mean blood-lead concentrations

reported based on this study may be higher than those based on the full registry .

An adjustment was made to the study database before the data summaries presented in

Appendix A were prepared or any statistical analysis begun . The adjustment was made to

remove R&R activities that occurred after blood sampling.

For each type of R&R activity about which questions were asked (inside painting, outside

painting, other repairs, and carpets and floors), the respondent was also asked when these

activities began and ended . Because of the time delay between blood sampling and the

interviews, some R&R activities that did not begin until after the blood sampling were included .

Therefore, if the start date of an activity was after the blood sampling date, then that activity was

treated as if it did not occur. For example, if the inside painting start date (Question 21) wa s

after the blood sampling date, then the responses to questions 10 through 25 were changed to

"no" or "missing" as appropriate in the study database . Many start dates were missing from the

interview data. This was interpreted to mean that the R&R activity began before the blood

sampling.

In 432 (of 3,654) cases, some R&R activity occurred after blood collection . However,

266 of these had either another R&R activity before blood collection or one with a missing start

date. Thus, only 166 (432 minus 266) fewer children were considered to have had any exposure

to R&R as a result of this filtering of R&R activity data .

For homes constructed after the 1978 ban on lead-based paint, R&R activities are not

expected to disturb any lead. Thus, R&R activities in these residences may not impact lead

exposures in the same manner as those conducted in pre-1980 homes . However, in this report,

R&R activities in post-1980 residences were treated identically to R&R activities in pre-1980

homes. Some statistical analysis were performed attempting to identify differences in risk due to

lead exposure between R&R activities performed in pre- versus post-1980 homes (se e

Section 3.3.2), but available data did not support the differences .

3 .1 .2 Characteristics of Sampled Childre n

Below are some key characteristics of children represented in the study database

(n=3650):

• Blood-lead concentrations

- 82 percent of children had blood-lead concentrations s6 μg/dL (not elevated)

- 10 percent of children had blood-lead concentrations of 7, 8 or 9 μg/dL (not

included)

- 8 percent of children had blood-lead concentrations z 10 μg/dL (elevated).

14
p. 25

• Blood sample collection technique

- 97 percent of blood samples were collected via the capillary technique (which

sometimes results in skin contamination) .

• Medical assistance status

- 37 percent of children received medical assistance .

• Race

- 78 percent of children were Caucasian .

• Year residence built

- 25 percent of children lived in residences built after 1978 (R&R activities in these

homes should result in lower lead exposure) .

• Tenure at current residenc e

- 22 percent of children lived in their current residences less than 1 year .

• Peeling paint

- <4 percent of children resided in residences with "a lot of peeling paint"3 (inside)

- <8 percent of children resided in residences with "a lot of peeling paints3

(outside).

• Prevalence of R&R activities

- in >40 percent of homes some interior painting occurred within the las t

12 months; and, in most cases (nearly 90 percent), it was done by someone living

at the home

- in 12 percent of homes some exterior painting occurred within the last 12 months

- in 22 percent of homes windows were repaired or new windows were installed

- in 22 percent of homes carpets were repaired or replaced .

• Child's age at blood sample collection

- 12 percent of children were less than 1 year old

- 32 percent of children were 1 year old

- 15 percent of children were 2 years old

- 15 percent of children were 3 years old

- 14 percent of children were 4 years old

- 13 percent of children were 5 years old

- <0.5 percent of children were 6 years old .

3 Because the definitions of lead-based paint hazards in the HUD guidelines (HUD, 1995) or the §403 Risk

Analysis (EPA, 1997) were too complicated for use during a telephone interview, "a lot of peeling paint"

was the terminology used in the questionnaire . See, for example, Question 6 in Appendix A .

15

-~6;
p. 26

• Occupational or hobby related exposure

- 31 percent of study children may have been exposed to lead as a result of the

occupation of a household membe r

- 43 percent may have been exposed to lead as a result of a hobby of a household

member.

• Household income

- 43 percent of children lived in households with annual incomes above $30,000

- 57 percent of children lived in households with annual incomes below $30,000 .

• Respondents education (most respondents were female )

- 52 percent of respondents had a high school education or les s

- 33 percent of respondents had some education beyond high school

- 16 percent of respondents were college graduates.

Because of the extended period (March to December) over which the blood samples of

children in this study were collected, blood-lead concentrations were examined to assess possible

seasonality. Previous work (EPA, 1995, and EPA, 1996) has indicated that there is a tendency

for children's blood-lead concentrations to be higher in the summer (warmer months) and lower

in the winter (colder months), possibly due to different activity patterns . Because longitudinal

blood-lead concentration data for individual children included in this study were not available,

blood-lead concentration trends were examined at an aggregate level . Figure 3-1 presents the

geometric mean blood-lead concentration in the registry database plotted as a function of sample

collection month with pointwise confidence intervals . Blood-lead concentrations appear to be

lower in the summer than the winter, which is inconsistent with previously reported work (EPA,

1995, and EPA, 1996). However, since the confidence intervals suggest that any evidence of a

seasonal trend in the blood-lead concentrations of children in the study is fairly weak, this effect

was not pursued further. Additionally, fewer nonelevated blood-lead concentration children were

sampled in October, November, and December, likely leading to the slight increase in blood-lead

concentrations observed in the data for those months.

3.1 .3 R&R Exposure Characterizatio n

Information on the frequency of general and specific R&R activities in residences

populated by young children is a valuable product of this study . While the main objective of this

study was to investigate the relationship between incidences of R&R activities and EBL children

(a dose-response type relationship), this information is most useful when the degree of exposure

is also known. In this case, if a slight increase in risk due to childhood lead exposure as a result

of R&R activity is detected, the implications must be considered in light of the numbers o f

children likely to be exposed .

16
p. 27

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Mar Apr May Jun Jul Aug Sep Oct Nov Dec

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Figure 3-1 . Trend Plot to Assess the Seasonality of

Blood-Lead Concentrations in the Registry

Database

Tables 3-2 and 3-3 list the frequencies and percentages summarizing the responses to

each question in the R&R activities portion of the questionnaire (Questions 10 through 71 in

Appendix A). The R&R activities portion is subdivided into four parts, with each part relating to

one of four distinct types of R&R activities that may increase lead contamination in homes:

"inside painting," "outside painting," "other repairs (windows)," and "carpets and floors (repair

or replacement) ." An examination of the questionnaire shows that each of the four parts contains

a set of similar questions concerning details common to all four types of R&R activity, such as

the method of surface preparation carried out for the activity . The first column in Table 3-2 lists

these questions, accompanied by the question numbers identifying the four interview questions

related to each type of activity (i .e., inside painting, outside painting, other repairs, carpets and

floors). The question numbers are in the same order as the activities listed in the columns

(e.g., Q19 related to using chemical paint removers for inside painting) . The remaining questions

from the R&R activities portion of the questionnaire are unique to only one of the four activities

and can be found in the first column of Tables 3-3a (inside painting), 3-3b (other repairs), and

3-3c (carpets and floors) with their respective question numbers .

17

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p. 30

Table 3-3a . Inside Painting Specific Exposure Summar y

Inside Painting

(n = 3654)

Question Response Frequency Percent

Was the R&R activity carried out in Yes 1858 50 .8%

the last 12 months? No 1786 48.9%

Q10 Don't Know 10 0.3%

Was any work done to repair broken 1

plaster or damaged walls in the 1005 27.5%

room/rooms you painted in the last Ye

s

12 months? No 2636 72.2%

Q11 Don't Know 12 0.3%

Was any work done where old walls Yes 395 10 .8%

were taken down or moved, while

working in your home? No 3252 89.0%

Q12 Don't Know 7 0.2%

Was the surface prepared by Yes 541 29 .1 %

methods such as sanding o r

scraping? No 1241 66

.8%

Q13 ('Yes' Don't Know 76 4.1%

to Q10)

In how many rooms in your home 8

was this work done? None 1 0.2%

Q23'('Yes' to Q13) 1 205 38

.5%

2 119 22.3%

3 67 12.6%

4 141 26.5%

Was any work done in the kitchen? Yes 222 41 .09'0

No 318 58.8%

Q24 ('Yes' to Q13)

Don't Know 1 0.2%

Was any work done in the Yes 239 44.2%

bathroom? No 301 55.6%

Q25 ('Yes' to Q13) Don't Know 1 0.2%

20

30
p. 31

Table 3-3b. Other Repairs (Windows) Specific Exposure Summa ry

Other Repairs (Windows)

(n = 3654)

Question Response Frequency Percent

Was the R&R activity carried out in Yes 805 22 .0%

the last 12 months?

No 2839 77.7%

Q39 Don't Know 10 0.3%

Was any work done to repair broken 1

plaster or damaged walls while

repairing or putting in the windows? Yes 153 19.0%

Q40 ('Yes' to Q39) No 637 79

.2%

Don't Know 14 1.7 %

Was any work done where old walls Yes 109 13.5%

were taken down or moved whil e

repairing or putting in the windows? No 691 85.8%

Q41 ('Yes' to Q39) Don't Know 5 0.6%

Was there any painting or were any Yes 235 29.2%

surfaces prepared for paint with the

installation of the new windows? No 561 69.7%

Q42 ('Yes' to 039) Don't Know 9 1.1%

21

31
p. 32

Table 3-3c . Carpets and Floors (Repair or Replacement) Specific Exposure Summar y

Carpets and Floors (Repair or Replacement)

(n = 3654)

Question Response Frequency Percent

Was the R&R activity carried out in Yes 816 22.3%

the last 12 months? No 2825 77.3%

0

39 Don'tKnow 13 0.4%

As a result of the work that was 1206

done in your home, were dust an d

dirt spread to . . .

. ? Only in the Work Area 903 36 .9%

In the Room next to the 264 10.8%

Q71 Work

Through the House 335 13 .7%

No Dirt or Dust 857 35.0%

Generated

Don't Know 89 3.6%

Do you have any wall-to-wall Yes 639 78.3%

carpeting in your home?

No 176 21.6%

Q55 ('Yes' to Q54)

Don'tKnow 1 0.1%

Did you replace or remove a wall-to- Yes 543 66.5%

wall or other large carpet in the last

12 months? No 269 33.0%

Q56 ('Yes' to Q54) Don'tKnow 4 0.5%

22

. ~~
p. 33

The complexity of the tables reflect the complexity of the skip patterns used in the

questionnaire. To illustrate how the setup in Table 3-2 works, take as an example the first row

(which is subdivided further into three subrows in all except the first column) and find the

number "703" in the fifth column of the first subrow. The first level label for the column is

"Frequency" and the second level label is "Outside Painting ." The first column labeled

"Question" for that entry contains the question "Was the R&R activity carried out in the last

12 months?" and the second column labeled "Response" contains the response "Yes ." Therefore,

"703" is the frequency of people who responded "Yes" to the R&R question that asked whether

any painting outside the house was carried out within the last 12 months . To pinpoint the actual

question in the questionnaire, go back to the first column, where four question numbers ("Q10,

Q28, Q39, Q54") are listed in the same order of R&R activity type as the columns . Since

"Outside Painting" is the second R&R activity type in the columns, the question of whether any

painting outside the house was carried out within the last 12 months was asked in Question 28 .

The percentage "19 .2%" in the column to the right of "703" refers to the same 703 who answered

"Yes" out of the 3,654 (which equals 703+2924 +27, the sum of the frequency of all possible

responses in the first row) who responded to Question 28 .

The numbers in the last two columns of Table 3-2, however, are slightly different from

the others, in that they summarize the responses across the four types of activities using an

amalgamation of the responses. Take again, for example, the first rows. If a respondent

answered "Yes" to any of Q10, Q28, Q39 or Q54, then the amalgamated response was set to

"Yes." If a respondent answered "No" to all of Q10, Q28, Q39 or Q54, then it was set to "No ."

Otherwise, the response was set to "Don't know." This amalgamation can be interpreted as a

response to the question "Was any R&R activity carried out in the last 12 months?," hence the

label "Any R&R Activity" in the second level of the column labels .

The double lines between some rows of Table 3-2 take into account the skip patterns in

the questionnaire, where only those respondents who answered "Yes" to a question above the

double line were allowed to answer the questions below the double line . For example, the

second and fourth rows are separated by a double line . Only those 541 people who were

responded "Yes" to Question 13 were asked to respond to Question 15 (notice that

541=166+356+19). Hence, the percentages below the double lines are conditional on answers to

previous questions. For example, the percentage of people who responded "Yes" to Question 15

is 30.7 percent (166/541).

Table 3-2 reveals the pattern of R&R activities for study participants. Based on all

participants, at least one of the four R&R activities had been conducted in 67 .2 percent of the

residences in the last 12 months, with around 50 percent conducting some inside painting and

approximately 20 percent each conducting outside painting, other repairs, and carpets and floors

(repair or replacement) (row 1) . Of the 2,456 houses where at least one of the four R&R

activities was carried out, some form of surface preparation (row 2) was performed i n

42.3 percent. Approximately 65 percent of outside painting involved some surface preparation,

compared to 15 percent to 30 percent for each of the other activities . This difference is not too

surprising since outside painting tends to require more paint removal than the other activities. As

for the type of surface preparation techniques employed, the conditional percentages do not vary

much within the rows (rows 3 to 8). Therefore, if any surface preparation was carried out, th e

23 -.7")
p. 34

type of R&R activity does not appear to affect the surface preparation technique used for the

activity. Most surface preparation involved some sort of hand scraping or hand sanding

(80 percent to 90 percent), whereas the use of open flame torches was rare (1 percent to

2 percent) . Heat guns were used 7 percent of the time, and chemical paint remover was used

13 .6 percent of the time .

The conditional percentages for the type of individual who carried out the surface

preparation also did not change much within the rows ; although owner, building superintendent,

and apartment staff were more likely to have been involved in any surface preparation for inside

or outside painting, whereas paid professional contractors were more likely to have been

involved in the other two R&R activities, which tend to require more skilled labor (rows 9 to 13) .

The head of household or spouse was involved in surface preparation work approximatel y

70 percent of the time, whereas others were involved 10 percent to 15 percent of the time .

Finally, some person was usually living at the home while surface preparation work was

being done . The percentages for inside painting and carpets and floors (repair or replacement),

which occurred inside the house, were lower than the percentages for outside painting and other

repairs (window), which involved more outside work (row 14) .

Tables 3-3a (inside painting), 3-3b (other repairs), and 3-3c (carpets and floors) contain

similar statistics for the questions unique to each R&R activity . Additional nonunique questions

from Table 3-2 are duplicated in some rows so that Tables 3-3a through 3-3c are set up similarly

to Table 3-2. The double lines separate the questions into components as before, wher e

participants were required to respond to a question in a component only if they gave a "Yes"

response to a particular question in the previous component . The parentheses next to the

question number contain the particular response and interview question . Note, for example, that

the frequencies in row 4 of Table 3-3a, where the question was responded to only by those

individuals who answered "Yes" to Question 10, add up to the frequency of "Yes" responses in

row 1(541 + 1241 + 76 = 1858).

Table 3-3a shows that very little of the painting activities required any nonsurface

preparation activities such as repairs to broken plaster or damaged walls (row 2) and taking down

or moving walls (row 3). In the homes where surface preparation was carried out for inside

painting, most were jobs involving one to three rooms, with just over a quarter involving more

(row 5). The results from Table 3-3b indicate that in homes where windows were either repaired

or replaced, broken plaster or walls were repaired 19 percent of the time (row 2), walls were

taken down or moved 13 .5 percent of the time (row 3), and painting or surface preparation for

painting was carried out 29.2 percent of the time (row 4) . Finally, of the homes where carpets

and floors were repaired or replaced, 78 .3 percent had wall-to-wall carpeting and 66 .5 percent

had wall-to-wall or other large carpet replaced or removed (rows 3 and 4 in Table 3-3c) .

3 .2 DATA QUALITY

Data from two sources are analyzed in this report: blood-lead registry data from

Wisconsin children outside of Milwaukee and Racine and interview data collected specifically

for this study from a subset of these same children . The blood-lead registry data reflect a

24
p. 35

continuing problem with reporting race and ethnicity in Wisconsin . (Ethnicity data are not

analyzed in this report due to these problems.) For example, of the 3,650 children in this study,

ethnicity was unknown for 97 percent of children . Medical assistance status was also unknown

for a portion of the children in the registry. This is not reflected in Table 3 .1 because one of the

criteria for a child being in this study was known medical assistance status . (This variable was

used in the study design. See Section 2 .0.)

Although this study was designed to separately assess the impact of R&R activities on

blood-lead concentrations for children receiving medical assistance and children not receiving

medical assistance, the results reported in Table 3-1, Section 3 .3, and Appendices A, C, and D

are based on both groups. Analysis of the preliminary data set, containing approximately

one-third of the full data set, indicated that similar relationships were observed for both groups .

Other potential data quality concerns include quality control procedures employed

during collection of blood-lead registry and questionnaire data, possible nonresponse and

sampling biases, and skin contamination in the blood-lead registry data. Section 3 .2.1 discusses

measures for ensuring the quality of the blood-lead registry and questionnaire data. Section 3 .2.2

discusses nonresponse and sampling biases . Section 3.2.3 addresses skin contamination.

3.2 .1 Blood-Lead Registry and Interview Dat a

Elevated blood-lead concentration (z l0μg/dL) has been a reportable condition in

Wisconsin since 1979 . In 1993 the law changed to require that all blood-lead tests be reported

for children under 6 years old . The Wisconsin State Health Department has encouraged

laboratories to report blood-lead concentration, but the law required a person who screens to

report results of testing of blood-lead concentrations of children under six . The law also requires

any person including doctors, nurses, hospital administrators, directors of clinical laboratories

and health officers who diagnoses lead poisoning (Z l0μg/dL) to report it regardless of the age of

the person tested.

The state department of health and family services is considering issuing rules to clarify

reporting responsibilities, but as of today only the statute ensures compliance with reporting . In

practice, this is a lab based system . Labs report to the health department . The health department

staff contact labs and doctors offices to obtain any missing demographic information and pass on

information about children with elevated levels to local health departments for follow-up.

Quality control of analysis is regulated by CLIA, the clinical laboratory improvement

amendments of 1988 . All commercial labs must participate in a HCFA approved proficiency

testing program such as the programs operated by the University of Wisconsin and the College of

American Pathologists.

Quality control of the sample collection is up to the sample collector. In practice, the

state department of health and family services, the state lab of hygiene, and local health agencies

work with health care providers to inform them of quality control issues that arise, especially

with capillary specimens.

25 ~~
p. 36

A number of measures were used to ensure interview data quality . When frequency

counts were run, a separate file was created for codes that were out of the range for the variable.

Errors were corrected using the original interviews. Consistency errors were infrequent . In some

cases, field sections were checked to clarify a problem, and sometimes the respondent wa s

recontacted to solve the problem . Finished codebooks and frequency runs were reviewed to

make sure that all data corrections were made .

3 .2 .2 Assessment of Nonresponse and Selection Bia s

Whenever a sample is selected, there is a potential for bias. For example, bias can be

introduced if careful interviewing practices are not followed . In this study, the interviewers were

specifically trained in administering telephone interviews . Further, the interviewers followed a

pre-designated script to collect the information from and to recruit participants . Training and

following a set script minimizes the potential for interviewer bias . Nonresponse is also a

potential source for bias in the sample estimates.

In general, bias in sample estimates is caused by differences between the population

parameters of participants and nonparticipants and, therefore, can be investigated by comparing

characteristics of participants in a study to those of nonparticipants (Thompson, 1992) . Due to

the mandatory screening of medical assistance children, it is unlikely that the Wisconsin

blood-lead registry is representative of the children of Wisconsin in many demographic features .

For example, the 1990 census reported that 95 percent of Wisconsin children outside of

Wisconsin and Racine counties are Caucasian . Only 67 percent of the children selected for the

study were Caucasian and only 78 percent of those participating . The registry sample had larger

percentages of African-Americans, Asians, and Native Americans than percentages reported by

the census. However, some of the difference between the census and registry sample racial

distributions may be due to the large percentage of unknown race children reported in the registry

sample (17%) as compared to the census (<1%).

Although incomplete reporting, i.e ., the large percentage of unknown race children, is a

problem for any study, the data selected for this study does not need to be representative of a

particular group of children to achieve the primary study objectives. The primary purpose of this

study was to establish a dose-response type relationship between incidence of general and

specific R&R activities and EBLs. This dose-response relationship is assumed to be applicable

to many similar populations.

In this nonresponse assessment, "participants" are children selected for inclusion and

participating in the study . "Nonparticipants" are children who were selected for inclusion in the

study, but did not participate for some reason (e .g., the child's guardian refused to be interviewed

or study personnel were unable to reach the child's guardian). However, even extreme

differences between participants and non-participants may not cause severe bias as long as the

participation rate is the same between children with blood-lead levels below 7 μg/dL (controls)

and children with blood-lead levels z 10 μg/dL (cases). Therefore, to investigate bias it is

important to examine the participation rate among the cases to that among the controls . This

does not mean that comparisons between characteristics of participants and nonparticipants are

without merit; these comparisons will serve to indicate the overall representativeness of th e

26
p. 37

selected sample of children compared to the registry population. In this section, we present the

results of both types of comparisons beginning with comparing the characte ristics of the

interviewed children to the sampled population .

A limited amount of information on the characte ristics of study participants was

available in the Wisconsin Bureau of Public Health's blood-lead registry. Besides blood-lead

concentrations, this information included the gender of the child, race of the child and parent,

child's birthday, and the child's age when the first blood-lead sample was collected . Table 3-4

presents a summary of demographic information for participants and nonparticipants. The last

column in the table presents the p-value for a statistical test comparing characte ristics of

participants and nonparticipants. For the two continuous variables (child's age and blood-lead

concentration), the p-value corresponds to a t-test comparing the mean levels between

participants and nonparticipants. For the categorical characteristics, the p-value corresponds to a

likelihood ratio chi-square statistic comparing the propo rtions of participants and nonparticipants

in the levels of the characte ristic.

With the exception of gender, characteristics of study participants were statistically

different from those of nonparticipants. However, in practical terms, these differences may not

be meaningful. For example, study participants were significantly older than nonparticipants;

but they were, on average, only 0 .137 years or approximately 1 .6 months older (95 percent

confidence interval from 0.81 to 2.5 months). The geometric mean blood-lead concentrations for

participants were signific antly lower than that of nonparticipants; on average, 1 .26 times lower,

with a 95 percent confidence interval of 1 .18 to 1 .35 times. The proportion of children with

blood-lead concentrations z 10 μg/dL was also significantly smaller for participants than

nonparticipants. It can be concluded that fewer EBL children could be located or agreed to

participate in the study (nonresponse bias).

27 37
p. 38

Table 3-4. Summary of Demographic Information for Participants and Nonparticipants

Variable Description Nonparticipants Participants P-value~

Sample size 5,004 3,654

25th Percentile 1 .1 1. 1

Age (Years) Mean (Standard Error) 2.55 ( 0.022) 2.69 ( 0 .028) 0 .0001

75th Percentile 3.9 4. 1

25th Percentile 1.68 1.27

Blood-Lead Geometric Mean (b) 3.11 2.47

Concentration (kg/dL) (Log Standard Error) (0.019) (0.028) 0.0002

75th Percentile 5 .75 4.80

Blood-Lead <10 pg/dL 89.73% 92 .09%____~ 0 .001

Concentration Group ~ 10 pg/dL 10.27% 7 .91 %

Gender of Child Female 47.96% 48.74% 0.171

Male 51.3% 50.85%

Unknown 0.70% 0.41 %

Race of Child Asian 9.19% 4.63% 0.001

African-American 9.37% 2.13%

Native-American 3.24% 1.48%

Caucasian 59.29% 78.02%

Unknown" 18.90% 13.74%

Race of Parent Asian 9.19% 4.60%

African-American 9.37% 2.13% 0

.001

Hispanic 8.05% 2.71%

Native-American 3 .24% 1.48%

Caucasian 59.17% 77.94%

Unknown 10.97% 11.14%

(a) This p-value corresponds to testing for significant differences between the study pa rticipants and nonpa rticipants . The

p-value is based upon a t-test for continuous variables and a X2 test for categorical variables .

(b) Geometric means and log standard errors were calculated accounting for censored values . Blood-lead concentrations

repo rted as 4 pg/dL or lower were considered to be left-censored, and values repo rted at or above 40 kg/dL were

considered to be right-censored . There were 3,095 left-censored and 13 right-censored values for nonpa rticipants .

There were 2,540 left-censored and 6 right-censored values for pa rticipants .

(c) A distinct identifier identifying Hispanic children is not present in the Wisconsin registry . Therefore the Unknown

category contains these children.

Greater differences were found when comparing the race of participants and

non-participants. In particular, a larger percentage of participants were Caucasian . This result

was true for both parents and their children . Thus, it will be important to consider race when

interpreting the results of this study .

Potential bias in the statistical results presented in Section 3 .3 were investigated by

comparing the participation rate among cases to that among controls. Unfortunately, we were

only able to investigate the potential bias for those variables included in the registry database .

28

3S
p. 39

Bias in the R&R results could not be fully investigated. The potential for bias was determined

by comparing the distribution of participation across the levels of a particular demographic

factors changed with blood-lead group . Using log-linear models, these comparisons were

performed by investigating the three-way interaction between the factor of interest, participation,

and blood-lead group . A significant three-way interaction indicates that the effect of the

demographic variable on blood-lead is confounded with participation. Table 3-5 presents

frequency tables that formed the basis for the tests, as well as the p-value associated with the

significance of the interaction term. The results of these tests indicate that the effect of a child's

age on blood-lead is confounded with participation. Therefore, the age of the child needs to be

included in the logistic regression models so that this source of variability can be accounted for.

However, care needs to be taken when interpreting the model estimates for this variable, because

of its potential confounding with participation .

3 .2 .3 Assessment of Skin Contamination

Six blood-lead concentrations were >40 μg/dl, in the study database. (Eleven additional

children in the registry database had blood concentrations >40 μg/dL.) All six measurements

were based on capillary samples (which can result in skin contamination of a sample) and had

one or two follow-up blood-lead measurements. Table 3-6 presents first, second, and third

blood-lead concentration measurements for these six children. In all cases presented, second and

third blood-lead samples were collected within a month of the first sample, making them

reasonable follow-up blood-lead measurements. [One month is the longest time span

recommended by CDC for confirming an elevated capillary blood-lead result (CDC, 1991) .]

The four children whose first blood-lead concentrations were greater than 40, but for

whom second and third measurements indicated nonelevated blood-lead concentrations (1, 2, 4,

and 6), were deleted from the study database. The two children for whom the confirmatory

blood-lead measurements supported a diagnosis of elevated blood-lead concentration were not

deleted from the database .

Blood-lead concentration data from the blood-lead registry database were examined for

possible biases due to blood sampling technique (i .e., capillary vs. venipuncture). Table 3-7

presents, for six age groups of children, confidence intervals for the ratio of capillary to

venipuncture geometric mean and logarithmic standard deviation blood-lead concentrations. The

blood-lead screening data available in the registry were collected primarily by the capillary

method. Thus, the sample size for the venous calculations is small . Based on Table 3-7, it can

be concluded that blood-lead concentration measurements taken via the capillary method were

not, on average, significantly higher than those taken via venipuncture for any age group . In fact,

it appears that, for children less than 1 year of age, there is a tendency for venipuncture

blood-lead measurements to be higher than capillary measurements.

29 39
p. 40

Table 3-5 . Comparison of Participation Between Cases and Control s

Children

with Children with

PbBz10 PbB<7

Variable Description ( Cases) (Controls) P-value

Gender of Child Female: % Participants 34.3% 43.8% 0.629

Total No . of Records 341 3378

Male: % Participants 37.4% 43.7%

Total No . of Records 457 3349

Unknown : % Participants 20.0% 33.3 %

Total No . of Records 5 36

Race of Child Asian % Participants 26.1 % 29.2% 0.867

Total No . of Records 111 41 4

African- % Participants 12.4% 15.4%

American Total No. of Records 97 364

Native- % Participants 37.5% 25.3%

American Total No. of Records 8 194

Caucasian % Participants 45 .2% 49.8%

Total No . of Records 458 4760

Unknown"' % Participants 29 .5% 35.8%

Total No . of Records 129 1 13 1

Race of Parent Asian % Participants 25.5% 29.2% 0.920

Total No . of Records 110 414

African- % Participants 12.4% 15.4%

American Total No . of Records 97 364

Hispanic % Participants 20.3% 19.4%

Total No . of Records 59 371

Native- % Participants 37.5% 25.3%

American Total No. of Records 8 194

Caucasian % Participants 45.1% 49.8%

Total No . of Records 452 4757

Unknown % Participants 39 .0% 43.6%

Total No . of Records 77 763

Age of Child Less than % Participants 49 .2% 38.6% 0.0004

1 Year Total No. of Records 63 937

1 Year Old % Participants 37 .6% 43.5%

Total No . of Records 266 2123

2 Years Old % Participants 34.2% 44.3%

Total No . of Records 152 981

3 Years Old % Participants 37 .0% 40.1%

Total No . of Records 127 1042

4 Years Old % Participants 31 .4% 40.8%

Total No . of Records 121 1030

5 Years Old % Participants 28.2% 59.4%

Total No . of Records 71 714

FYears Old % Participants 33.3% 47.2%

Total No . of Records 3 36

(a) A distinct identifier identifying Hispanic children is not present in the Wisconsin registry . Therefore the Unknown category

contains these children .

30

~
p. 41

Table 3-6. Six Capillary Blood-Lead Concentration Measurements with Possible Ski n

Contamination Bias

Blood-Lead Concentration Measurement (pg/dL)

Child First Second Third

1 58 8 •

2 61 4 4

3 62 59 29

4 76 4 •

5 85 21 17

6 140 8 •

• Elevated blood-lead measurements in the shaded rows were assumed not to be

from contamination . Measurements in nonshaded rows were assumed due to skin

contamination and were removed from the study database .

Table 3-7 . Assessment of Skin Contamination of Capillary Blood Samples for Six Age

Groups of Children'

Capillary Venipuncture

Logarithmic Logarithmic

Age Group Geometric Standard Geometric Standard

(years)b Sample Size Mean Deviation Sample Size Mean Deviation

< 1 1048 1.76 0.0057 31 3.93 0.021

1-2 2639 3.05 0.00070 89 3.28 0.021

2-3 1250 3.22 0.0014 41 4.30 0.032

3-4 1318 3.19 0.0012 38 4.15 0.019

4-5 1248 2.80 0.0018 39 3.73 0.021

5-6 821 2 .33 0.0041 52 2.42 0.053

Age Group Geometric Mean Ratio Logarithmic Standard Deviation Ratio

( years) ( Capillary/Venipuncture) ( CapillaryNenipuncture)

Estimate 95% Confidence Interval Estimate 95% Confidence Interval

< 1 0.45 [0.32, 0.621° 1.67 [1.09, 2.551`

1-2 0.93 [0.69, 1 .24] 0.94 [0.72, 1 .24]

2-3 0.75 [0.52, 1 .08] 0.97 [0.68, 1 .38]

3-4 0.77 [0.58, 1 .02] 1.29 [0.89, 1 .87]

4-5 0.75 [0.56, 1 .011 1 .40 [0.94, 2.09]

5-6 0.96 [0.60, 1 .551 1 .18 [0.74, 1 .88

( a) Results calculated using censored data techniques . Blood-lead concentrations of 4 Ng/dL were treated as

left-censored at 4 Ng/dL and blood-lead concentrations > 40 pg/dL were treated as right-censored at 40 jrg/dL.

(b) The categorization scheme for the age group categories is :

< 1 : 0 months s age < 12 months

1-2 : 12 months s age < 24 months

2-3 : 24 months s age < 36 months

etc .

(c) Statistically significant results at the 5 percent significance level.

31 1#
p. 42

There may be some selection factors that relate to type of blood sampling method.

CDC 1991 states that elevated blood-lead results obtained on capilla ry specimens are

presumptive and must be confirmed using venous blood and that children at the highest ri sk

should be given the highest priority for screening. Thus, physicians are more likely to perform

initial venous screenings on high risk children. Non-random selection of children for initial

venous screenings may be the reason venipuncture blood-lead measurements are higher than

capillary measurements among children less than 1 year of age . This does not preclude the

possibility of skin contamination affecting individual blood-lead concentration measurements,

but suggests that, in general, blood-lead concentration measurements taken by the capillary

method should not be adjusted downward.

The variation in blood-lead concentrations, as measured by the ratio of loga rithmic

standard deviations, was statistically different between the two groups only for children less than

1 year of age. Variability in blood-lead concentration measurements among children less than

1 year of age was larger among those children sampled by the capillary method. This could be

because children less than 1 year of age who receive venous blood-lead screening are mostly

alike in that they are at high risk of lead exposure .

3 .3 STATISTICAL ANALYSI S

Children were selected into this study based on their observed blood-lead concentrations .

Since the purpose of this study was to assess the impact of R&R activities on children's

blood-lead concentrations, an analysis methodology that respects the fact that observations were

chosen based on the value of the response variable must be used. One such inference mechanism

is the odds ratio . The odds ratio is the natural form of inference based on logistic regression .

The data collected in this study were analyzed using logistic regression . Logistic

regression is a statistical method used to explain the relationship between a dichotomous

response variable and a suite of explanatory variables. The dichotomous response variable

analyzed is an indicator of elevated or nonelevated concentration. The explanatory variables

provide information on social and demographic factors affecting children ( e .g., household

income), as well as on R&R activities conducted in children's residences (e.g., surface

preparation for indoor painting) . Appendix B discusses logistic regression and the odds ratio in

detail.

Two types of logistic regression analyses were conducted. First, univari ate regressions

were performed for each expl anatory variable. Both blood-lead registry variables and

questionnaire responses were analyzed . Only six blood-lead registry variables were available .

The statistical significance for each of the blood-lead registry variables was assessed and is

presented in Table 3-1 . Because of the large number of interview questions (and possible

responses), the univariate logistic regression results based on the interview questions were

considered together to assess statistical significance. Univariate logistic regression results are

presented in Section 3 .3 .1 . When the univariate logistic regressions were car ried out for every

single question in the questionnaire, the research question being asked was "Are any of the

variables related to incidence of elevated blood-lead?," which is, in effect, the universal

hypothesis . In this stage of the analysis, the Holm procedure, a modification of the Bonferonni

32 ~~
p. 43

method (Holm, 1979) was used to adjust for the many simultaneous inferences being made .

Later, in the multivariate analysis, specific questions such as "Is there an increased risk due to

any R&R activity?," were each considered independently, without adjustment for multiple

comparison (Savitz et al., 1995).

Second, because it is known that a number of social and demographic factors affect

children's blood-lead concentrations (Bornschein et al ., 1985 ; Brody et al ., 1994 ; Lanphear et al.,

1996), multivariate logistic regression analyses were performed to assess the significance of

certain R&R variables after accounting for known effects . To account for known factors

affecting blood-lead concentration, a baseline (multivariate) logistic regression model was

developed to explain the risk of an elevated blood-lead concentration. This baseline model, as

well as the results from introducing R&R variables into the baseline model, are presented in

Section 3 .3 .2.

3 .3 .1 Univariate Statistical Analyses

Univariate logistic regression was used to assess the odds of an elevated blood-lead

concentration among various groups of children. A separate logistic regression analysis was

performed for each interview question and blood-lead registry variable . Odds ratios were

estimated to compare the odds of elevated blood-lead concentrations for children in each

response category .

An odds ratio is a fraction, with the odds for one group of children in the denominator

and the odds for a second group in the numerator (see Appendix B) . The odds are the probability

that a subject has some condition over the probability that a subject does not have the condition.

If the odds are about the same for the two groups, then the ratio is close to 1 . An odds ratio

statistically greater than 1 indicates that the second group of children (numerator group) is at

higher risk for the specified condition than the first group (denominator group). For these

analyses, the odds are the probability of a child having an elevated blood-lead concentration

relative to the probability of a child not having an elevated blood-lead concentration . The two

groups of subjects are defined by their responses to a particular question or values of a registry

variable. For example, the odds ratio for males versus females could be estimated .

In preliminary statistical analysis, logistic regression using two possible definitions of

nonelevated blood-lead concentrations was performed . For the first statistical analysis,

blood-lead concentrations Z 10 μg/dL were considered elevated, but only those blood-lead

concentrations <7 jig/dL were considered not elevated .' Subjects with blood-lead concentrations

between 7 and 10 μg/dL were not considered. For the second statistical analysis, all blood-lead

concentrations <10 μg/dL were considered not elevated. Elevated blood-lead concentration was

always defined as z 10 μg/dL based on the Centers for Disease Control and Prevention definition

(CDC, 1994).

4 The cutoff for nonelevated blood-lead concentrations was chosen arbitrarily based on the study design,

which dictated 100 percent sampling of children with blood-lead concentrations >7 μg/dL.

33 ~~
p. 44

The second definition of not elevated (<10 μg/dL) is appealing because it allows al l

observations to be used in the analysis and, thus, increases its statistical power by increasing the

sample size. However, the sample size of the nonelevated group is much larger than that of the

elevated group by either definition. Because excluding medium blood-lead concentration s

(7 μg/dL - 10 μg/dL) may magnify the difference between high and low groups, the first

definition may permit better detection of the covariates that affect a child's risk of an elevated

blood-lead concentration . Preliminary analysis suggested that the results would be similar based

on both definitions of nonelevated blood-lead concentration . Therefore, the first definition of

<7 μg/dL was used for nonelevated blood-lead concentration in all further analysis .

Blood-lead concentrations z 10 μg/dL were considered elevated .

Columns 10, 11 and 12 of Table 3-1 present univariate logistic regression results for

each of the blood-lead registry variables. Column 10 is the estimated log odds difference, 11 the

standard error of the log odds difference, and 12 a p-value indicating statistical significance . The

log odds difference is the logarithm of the odds ratio . Thus, exponentiating the log odd s

difference yields the odds ratio.

For each of the six variables for which results are presented in Table 3-1, there is one

level with no values recorded in columns 10, 11 and 12 . This was the reference group for the log

odds differences reported for the other levels of the variable . For example, no log odds

difference values are reported for the "Caucasian" level of the race variable . Thus, each of the

other levels ("African-American," "Asian," "Native-American," and "Unknown") of log odds

differences compare that level to "Caucasian . "

Based on the logistic regression results reported in Table 3-1, African-Americans and

Asians are estimated to be e0- 92 = 2 .5 and e' °3 = 2.8, respectively, more likely to have elevated

blood-lead concentrations than Caucasians. Males are more likely than females to have elevated

blood-lead concentrations (e+0.34 = 1 .4), and 1 year olds are more likely than 5-year olds (e+0 .87 =

2.4). Other results were not statistically significant .

A complete presentation of the logistic regression results from the questionnaire data is

provided in Appendix A. Of the variables in Appendix A, Appendix C lists all variables

significant at the 10 percent level . Of the variables in Appendix C, Table 3-8 lists those

significant at a 10 percent experiment-wise level based on the Holm multiple comparison

procedure.

When many tests of significance are conducted, some statistically significant results

might be obtained due to chance, even if there were no "real" effects . Thus, for 181

simultaneous tests, 18 significant results could be expected at the 10 percent significance level,

even if there were no responses related to the probability of elevated blood-lead concentrations .

The Holm procedure, a modification of the Bonferroni procedure (Holm, 1979), was

used to protect against making errors due to random chance (assigning significance when there is

no real effect, "false positive") while simultaneously making 181 inferences, i.e., interpreting

181 tests of significance . This procedure yielded an overall "experiment-wise" confidence level

of 90 percent. That is, when determining significance, all 181 tests are considered together,

34

1ILL
p. 45

controlling the probability of making a "false positive" claim simultaneously across all 181 tests.

Table 3-8 presented questions that were significant at the 90 percent confidence level using the

Holm procedure.

Table 3-8. Significant (Based on the Holm Procedure) Univariate Odds Ratio Estimates and

Confidence Intervals°

All Children with Blood-Lead Concentrations <7 pg/dL or z 10 pg/dL

n = 3,288

Odds Ratio

Higher Risk Lower Risk

Question Group Group Estimate 95% Confidence Interval

Q17 Heat guns used (inside) Yes No 3.456 [1 .584, 7 .538]

Q4C Year residence was built Pre-1940 Post-1980 3 .32 [1 .105, 9.9741

Q1 Rent or own current residence Fee Free b Rent 2 .974 [1.209, 7.3161

Q6 Very little, some, or a lot of A lot of None or Very 2.691 [1 .665, 4.3491

peeling paint ( inside) Peeling Paint Little Peeling

Paint

Q1A Type of building (current) Apartment/ Single Family 2.612 [1.786, 3.819]

Condo with 4 Home

or Fewer Unit s

Q2 Year current residence was built Pre-1940 Post-1980 2 .586 [1 .699, 3.9351

Q2 Year current residence was built Pre-1940 1970-79 2 .226 [1 .377, 3.5971

Q4B Type of building (previous) Apartment/ Single Family 1 .859 [0.923, 3.7431

Condo with 4 Home

or Fewer Unit s

Q4B Type of building (previous) Duplex Single Family 1 .804 [0.951, 3.4211

Home

Q1A Type of building (current) Duplex Single Family 1 .522 [1.105, 2.096]

Home

Q6 Very little, some, or a lot of Some Peeling None or Very 1 .462 [1 .041, 2.0541

peeling paint (inside) Paint Little Peeling

Paint

Q13 Surface prepared by sanding or Yes No 1 .419 [1 .03, 1 .9541

scraping (inside )

Q1 Rent or own current residence Rent Own 1 .405 [1.083, 1 .8221

Q3 Has the tested child lived in No Yes 1 .336 [1 .01, 1 .768]

(current) home longer tha n

12 months

Q1 1 Any repair to broken plaster or Yes No 1 .31 [0.99, 1 .7331

damaged walls in the room/rooms

painted

(a) These question responses are significant using the Holm's procedure at a 10 percent experiment-wise

significance level .

(b) "Fee free" means the respondent and child live free (no rent) . For example, they live with grandparents .

35 ~~
p. 46

However, the Holm procedure conservatively corrects for the possibility of "fals e

positives" by possibly creating "false negatives"5 (Savitz et al ., 1995). Therefore, test-wise

significant results were preserved and are presented in Appendix C . Based on what is already

known about lead exposure and elevated blood-lead concentration, some of these results may

represent useful information .

To save time during the telephone interview, the questionnaire was designed so that

groups of questions regarding a particular R&R activity would be skipped if the response to the

first question was negative (see Section 3.1 .3). Thus, for questions such as "Were heat guns

used?," a large number of values are missing . Those missing values indicate that heat guns were

not used because paint removal did not occur at all . Therefore, for the logistic regression

analyses reported in Appendix A and summarized in Table 3-8 (and Appendices C and D),

missing values such as these were treated as "No" responses .

In Table 3-8, "Higher Risk Group" and "Lower Risk Group" refer to the odds of having

an elevated blood-lead concentration and indicate the group more or less likely to have elevated

blood-lead concentrations, respectively. For example, the table can be read "Children in the

higher risk group are odds ratio times more likely than children in the lower risk group to have

elevated blood-lead concentrations ." Specifically, children who live in homes where heat guns

were used (to prepare a surface for interior painting) are 3.45 times more likely to have elevated

blood-lead concentrations than children in homes where heat guns were not used. Here "not

used" can mean either heat guns were not used while preparing a surface for interior painting or

no interior painting was done.

Table 3-8 presents 95 percent confidence intervals for each of the significant odds ratios

given. Some of these intervals include "1" because this is a more stringent confidence level than

that used for determining whether a question was significant . Odds ratios presented in Table 3-8

were sorted by magnitude .

Three R&R-related questions had (experiment-wise) statistically significant odds ratios .

The ratio was significant for using heat guns (inside), preparing surfaces by sanding or scraping

(inside), and repairing broken plaster or damaged walls (interior) . Odds ratios were also

(experiment-wise) significant for a number of demographic, housing-related, and

occupational/hobby questions. As seen in Appendix C, the following additional R&R-related

questions were test-wise significant :

• The number of rooms where work was don e

• Whether windows were repaired or new windows put in

• Whether work was done in the bathroom

• Whether work was done in the kitchen

• Whether heat guns were used (floor surface or covering disturbed)

• Whether carpet was replaced or removed or painted floors refinished

• Who did the (carpet or floor) work (owner, building superintendent, staff)

5 Not assigning significance when there is a real effect is a "false negative . "

36
p. 47

• Whether chemical paint removers were used (inside )

• Whether washing, wet scraping, wet sanding, or water blasting were used (outside)

• Whether power sanding, grinding, or sandblasting was used (outside)

• Whether chemical paint removers were used (outside)

• Whether there was any outside painting

• Whether an open flame torch was used (outside)

• Whether heat guns were used (outside)

• Who did the (outside) work (relative/friend not in household )

Given the conservative nature of the adjustments used to account for simultaneous inference, it is

likely that some of these results may be of public health significance . Recall that considering

only the experiment-wise statistically significant results and not the test-wise statistically

significant results increases the chance of not detecting significance when there is a real effect

(false negatives). The experiment-wise results do, however, properly ensure against the chance

of detecting significance when there is no real effect (false positive) .

3.3 .2 Multivariate Statistical Analyse s

The basic approach for the multivariate statistical analysis consisted of the following

steps:

1

. Combine responses from various social, demographic, and other non-R&R variables,

based on the results of the univariate analyses, for use in a multivariate logistic

regression model explaining blood-lead concentration

2. Construct a baseline logistic regression model of the probability of a child's

blood-lead concentration being greater than or equal to 10 μg/dL as a function of the

social, demographic, and other non-R&R-related variables

3

. Define composite R&R variables that characterize R&R activities based on the

questionnaire responses

4. Assess whether R&R activities are associated with a significant increase in the

probability that blood-lead concentrations will be greater than or equal to 10 μg/dL by

introducing the R&R variables into the baseline model .

Baseline Model . Steps 1 and 2 of this analysis yielded a baseline logistic regression

model. The variables considered in constructing the baseline model are detailed in Table 3-9 .

These variables were constructed from a combination of data provided from the blood-lead

registry and the questionnaire . The variables considered for the baseline model can be divided

into three types: 1) variables defining the type and condition of the child's residence ,

2) demographic factors describing the child and the child's family, and 3) variables identifying

known sources of lead exposure affecting the child .

37 ,/
p. 48

Table 3-9 . Variables Considered for the Baseline Logistic Regression Mode l

Variable Levels Basis

Type and Condition of Residenc e

Peeling Paint Inside or Outside° Yes/no Q6 or Q7 of questionnaire

Home Age <1960; z 1960 Q2 or Q4c of questionnaire

Rent or Own Rent/Own Q1 of questionnaire

Type of Residence Single family; duplex ; apt. with four Q 1 a or Q4b of questionnaire

or fewer units; apt. with five or

more units; mobile homeltrailer;

don't know/refused

Demographic Factors

Medical Assistance Status Medical Assistance/Nonmedical Blood-lead registry variable

Assistanc e

Income <30,000; z30,000 Q335 of questionnaire

Number of People 1, 2, 3, . . . Q333 ofquestionnaire

Education Level High school or less ; some education Q333d of questionnaire

beyond high school; colleg e

graduate

Age Quadratic and linear effects of age Age in days was calculated from

were considered. the blood-lead registry variable s

for samples called on date and

birthdate .

Other Known Lead Exposures

Adult Exposure" Yes/no Q306 - Q322 or 0324 - Q332 of

questionnaire

( a) If the answer to any of the following questions was yes, this indicator variable was set to 1 .

Because 22 percent of the children in this study moved during the year prior to their

telephone interviews (see Appendix A, Question 3) and because telephone interviews were

collected several months after blood sampling, dates of blood sampling were compared to the

reported move date for each of the 809 families who moved . The child's residence during the

month of blood collection was used to determine the home age and type of residence variables .

Peeling paint and rent-versus-own questions were not asked for the respondent's previous

residence. Thus, these variables were set according to current residence responses for all

children. Three hundred sixty-eight families moved after the month of blood collection .

Backwards variable selection was used to select the baseline logistic regression model

using the variables provided in Table 3-9 (Neter and Wasserman, 1974) . Three variables

describing the type and condition of the child's residence were significant in the baseline model :

age of home, type of residence, and peeling paint . Five demographic variables describing the

child and the child's family were significant in the model : education level, medical assistance

status, family income, number of household residents, and child's age (both the linear an d

38 _j~
p. 49

quadratic effects). Adult exposure, the only variable indicating possible exposure from a source

other than lead-based paint, was also significant in the model .

Income and medical assistance status are related variables . However, because children

were selected into the study with their medical assistance status taken into consideration and

income is believed to be a more reliable data response, both terms were kept in the model . Older

housing was defined to be pre-1960 housing . This decision was made based on the univariate

analysis of the age of house variable provided in Appendix A (Q2) . This analysis suggested that

only post-1970 housing could be statistically distinguished from pre-1940 housing in terms of

the odds of an elevated blood-lead concentration . In order to achieve a more even distribution of

observations between the older and newer housing groups, 1960-1970 homes were added to the

newer group .

Table 3-10 presents estimated odds ratios and corresponding 95 percent confidence

intervals for each of the categorical baseline model variables . Figures 3-2 and 3-3 present plots

of estimated odds ratios for a child's age and number of household residents . In the odds ratios

depicted in Figures 3-2 and 3-3, the reference group for the numerator of the odds ratio is

specified by the x-axis value . The reference group for the denominator of the odds ratio is held

constant in these figures. For Figure 3-2, the reference group for the denominator is 1-year-old

children. Figure 3-2 shows that a child's risk of having an elevated blood-lead concentration

level peaks at around age 2 . By age 4, the risk is lower than it is for 1 year olds. Note how the

confidence interval narrows as age increases due to the negative correlation between the

estimated effects of the linear and quadratic terms. In Figure 3-3, the reference group for the

denominator is children living in a home with three residents. Figure 3-3 indicates that more

people living in a child's home increases the risk of an elevated blood-lead concentration . Odds

ratios are provided rather than parameter estimates for the baseline model to aid in interpreting

the model.

Addition of R&R Variables into Baseline Model . The next step was to construct R&R

variables from questionnaire responses for incorporation into the baseline model . Following

that, the R&R variables were added as explanatory variables to the baseline model, and the

significance of the added variables was assessed.

Both individual R&R variables, based on questionnaire responses from a single question,

and composite R&R variables, based on responses from multiple questions, were constructed .

The composite R&R variables generally correspond to the variables constructed for the "Any

R&R Activity," column of the "R&R Activity Exposure Summary" table (Table 3-2), and the

individual R&R variables generally correspond to the variables constructed for Table 3-3 . As

noted in the discussion of these tables, most of the composite variables (particularly the specific

surface preparation activities) exhibited similar exposure patterns across all four types of R&R

activity. Use of the composite R&R variable rather than the individual question responses in the

multivariate analysis assumes that the effect of activities like "use of a heat gun" on blood-lead

concentration was the same any time a heat gun was used to remove paint, regardless of whether

39 ~/ ~
p. 50

1 . 9

1 .8

1 .7

1 .6

1 .5

1 .4

1 . 3

01 .2

1 .0

b0.9 -

8

0 . 8

0 .7

0 .6

0 .5

0 .4

0 .3

F- 1 dds R o f C~ f~

0

.2 ------- ~ppeZr' ~~~ ~onfiQence BounQ

0 .1

0 1 2 3 4 5 6

AGE

Figure 3-2. Odds Ratio Comparing Odds of an Elevated Blood-Lead Concentration for a

Child of Age Specified by the x-Axis to a 1-Year-Old Child's Odd s

2 .8

2 .7

2 .6

2 .5

2 .4

2 .3

2 .2

2 . 1

02 .0

1 .9

a1.8

b1 .7

91 . 6

1 .5

1 .4

1 .3

1 .2

1 .1

1 .0 --- --------------- + ~f Odds RI o

g C fi dence oun

0'9 Uppei ~ Confidence Bound

0 .8

d

2 3 4 5 6 7 8 9 10

Number of Household Residents

Figure 3-3 . Odds Ratio Comparing Odds of an Elevated Blood-Lead Concentration for a

Child in a Household with Number of Residents Specified by the x-Axis to a

Child in a Household with Three Residents

40 ,-A
p. 51

Table 3-10. Odds Ratio Estimates and Confidence Intervals for Baseline Logistic

Regression Model

Higher Risk Odds Ratio 95% Confidence

Variable Group Lower Risk Group Estimate Interval

Adult Exposure Yes no 1 .318 [1.055, 1 .6461

Education Level High School or College Graduate 1 .385 [0.999, 1 .919]

less or More

High School or Some College 1 .305 [1 .032, 1 .6511

less

Home Age Older Newer 2.104 [1 .632, 2 .713]

Income < $30,000 > $30,000 1.901 [1.492, 2 .422]

Medical Assistance Status No Yes 1 .360 [1.078, 1 .715]

Peeling Paint Indicator Yes no 1.487 [1 .191, 1 .857]

Type of Residence Single Apt.z Five Units 2.127 [1 .130, 4.003]

Mobile Single 1 .166 [0.749, 1 .817]a

Apt .s Four Single 1.658 [1 .098, 2 .504]

Units

Duplex Single 1 .864 [1 .371, 2 .534]

( a) Not a statistically significant odds ratio .

it occurred during interior or exterior painting, other repairs, or carpets and floor repair or

replacement, or any combination of the four R&R activity types. Table 3-11 presents the R&R

variables constructed, as well as the questions that provided the basis for the variables.

The constructed R&R variables for the multivariate analysis were coded a little

differently from those constructed for Tables 3-2 and 3-3 . If respondents who were not asked a

particular question because of the skip patterns in the questionnaire, the R&R variable for the

question was coded as "No" instead of "Missing ." (Questions with ordinal responses such as the

"number of rooms in which work was done" had the respective R&R variable set to 0 instead of

"Missing"). This coding change resulted in more observations being included in the multivariate

analysis, where any observation with an explanatory variable set to "Missing" would have been

excluded in the logistic regression.

Five sets of logistic regression models were created using the constructed R&R variables

in increasing order of complexity . In the first set, each R&R variable in Table 3-11 was the

single exploratory variable in a set of univariate logistic regressions. This univariate analysis

was carried out as a preliminary step in the multivariate analysis for exploring the effect of the

R&R variables. In the second set of models, each R&R variable was individually included as an

explanatory variable in the baseline model (i.e., each model could only have one R&R

explanatory variable). The third set of models was developed from the second set by including

all the other R&R variables that "nest" the single R&R variable already in the model . A variable

is said to "nest" another if the value of the former restricts the value of the latter . In the case of

R&R variables, "nesting" occurs due to the skip patterns in the questionnaire, where the response

to one R&R question can determine whether another question is skipped (remembering that

41

5'/
p. 52

variables were coded "No" or 0 if the question was skipped) . The fourth set consisted of a single

model that was created by including all the R&R variables in Table 3-11 as additional

explanatory variables in the baseline model. A restricted form of stepwise backward elimination

was carried out on this model, where explanatory variables could be eliminated only if they were

insignificant variables that did not nest another variable in the model . In the final set of models,

a single interaction term between an R&R variable and an age-of-house variable (pre- versus

post-1980) was added to the baseline model to test whether a ban on lead paint in 1978 reduced

the association between incidence of R&R activities and elevated blood-lead concentrations in

children. Note that all sets of models except the first use the baseline model as a basis on which

to build the models. Hence, in the interpretations to follow, the R&R effect in the last four sets

of models should always be implicitly qualified with the expression "taking into account the

effect of non-R&R factors on the risk of elevated blood-lead concentrations in children . "

Table 3-11 . Renovation and Remodeling Variables Used to Assess Relative Ris k

Indicator of R&R

Variable

Activity _T _Levels Basis° F

Any R&R Work Yes/No Q10, Q28, Q39, Q54

Inside Painting Yes/No Q10

Window Repair or Replacement Yes/No Q39

Inside or Outside Painting Yes/No Q10, Q28

Prepared Surface Yes/No Q13, Q29, Q42, Q57

Prepared Surface for Inside Painting Yes/No Q1 3

Hand Sanding or Scraping Yes/No Q14, Q30, Q44, Q58

Power Sanding, Grinding, Sandblasting Yes/No Q15, Q31, Q45, Q59

Open Flame Torch Yes/No Q16, Q32, Q47, Q60

Heat Gun Yes/No Q17, Q33, Q48,061

Washing, Wetscraping, Water Blasting Yes/No Q18, Q34, Q49, Q62

Chemical Paint Removers Yes/No Q19, Q35, Q50, Q63

Who Did the Work?

Head of the Household or Spouse Yes/No Q20_1, Q36_1, Q51_1, Q64_1

Other in Household Yes/No Q20_2, Q36_2, Q51_2, Q64_2

Relative or Friend Not in Household Yes/No Q20_3, Q36_3, Q51_3, Q64_3

Owner or Apartment Staff Yes/No Q20_4, Q36_4, Q51-4, Q644

Professional Yes/No Q20_5, Q36_5, Q51_5, Q64_

Lived in Home While R&R Was Done Yes/No Q22, Q30, Q53, Q66

Number of Rooms 0-14 Q23

R&R Work in Kitchen Yes/No Q24

(a) If the answer to any of the following questions was yes, this indicator variable was set to 1 .

42 ,52

.
p. 53

Appendix D presents univariate logistic regression results from the first set of models and

some descriptive statistics for each of the R&R variables described in Table 3-11 . Significant

R&R activity results were indicated for :

• Conducting any R&R work

• Painting done inside or outside

• Preparing surfaces

• Power sanding, grinding, sandblasting

• Using heat guns

• Washing, wetscraping, waterblasting

• Using chemical paint remover s

• Who did the work (owner or apartment staff)

• Living in the home while R&R work was done

• Number of rooms

• Work done in kitchen .

Table 3-12 lists the p-values of the estimated coefficients, the odds ratios, and confidence

intervals of the odds ratios for the R&R va riables from the second set of models. The odds ratios

in this set of models compare the odds of a child having elevated blood-lead concentrations

when a particular R&R activity occurred against the odds of a child having elevated blood-lead

concentrations when the particular R&R activity did not occur . To illustrate, take the case where

"Open Flame Torch" was included as the single R&R expl anatory variable. The odds ratio

compares the risk of a child having elevated blood-lead concentrations when an open flame torch

was used against the risk of a child having elevated blood-lead concentrations when no open

flame torch was used, which included the case when no surface preparation (or, for that matter,

any R&R activity) was carried out. The reason for calling these odds ratios "unconditional" will

become clear when the "conditional" odds ratios are defined.

The signific ant results in Table 3-12 indicate that R&R activities of some kind

significantly increase the odds of a child having elevated blood-lead concentration, although this

result appears to be partially driven by the effect of "Outside Painting," as evidenced by the

significance of "Inside or Outside Painting" and the insignificance of "Inside Painting ." Many of

the particular R&R activities lead to signific antly increased risk. The odds are higher when a

greater number of rooms are worked on . Results also indicate that the odds of an elevated

blood-lead concentration is higher if R&R work is either not done or conducted by someone that

is not an "Other in household" than the odds if R&R is conducted by an "Other in household."

The odd feature of this result is that no R&R work done is a subset of the higher risk group . This

last result is the only statistically signific ant result in this study that indicates that an R&R

activity of any type conducted by any individual could reduce the risk due to lead exposure. The

univariate logistic regression also showed that someone not in the household carrying out the

work reduced the odds of an EBL, although the result was not statistically signific ant

(Appendix D).

Table 3-13 lists the p-values of the estimated coefficients, the odds ratios, and the

confidence intervals of the odds ratios of all the R&R va riables from the third set of models,

43 01-3
p. 54

Table 3-12. Unconditional Odds Ratios from Logistic Regression with Single R& R

Variables

Confidence

Variable Hi her Risk Lower Risk P-Value Odds Ratio Inte rval

Any R&R Work Yes No 0.0220 1.309* (1.035,1 .656)

Inside Painting Yes No 0.9267 1.010 (0.814,1 .252)

Window Repair or Yes No 0.4652 1.095 (0.855,1 .402)

Replacement

Inside or Outside Paintin Yes No 0.0116 1.322* 1 .060 1 .649

Prepared Surface Yes No 0.0038 1 .430* (1 .117,1 .830)

Prepared Surface for Inside Yes No 0 .0645 1 .325 (0.977,1 .796)

Painting

Hand Sanding or Scraping Yes No 0.1158 1.226 (0.946,1 .588)

Power Sanding, Grinding, Yes No 0.1035 1.372 (0.930,2 .025)

Sandblastin g

Open Flame Torch Yes No 0.0101 4.883* (1.423,16.759)

Heat Gun Yes No <0.0001 4.597* (2.715,7 .782)

Washing, Wetscraping, Yes No 0.0092 1.625* (1.119,2 .360)

Water Blastin g

Chemical Paint Removers Yes No 0.0046 1 .969* (1 .220,3 .176)

Who Did the Work?

Head of the Household or Yes No 0.1696 1 .214 (0.915,1 .611)

Spouse

Other in Household No Yes 0.0355 3.000* (1 .055,8 .531)

Relative or Friend Not in Yes No 0.0015 2.231* (1 .344,3 .705)

Househol d

Owner or Apartment Staff Yes No 0.4787 1.244 (0.672,2 .305)

Professional Yes No 0.1195 1 .490 (0.893,2 .486)

Lived in Home While R&R Yes No 0 .0163 1 .365* (1 .054,1 .769)

Was Done

Number of Rooms 1° 0 b 0.0007 1.119* (1.047,1 .197)

R&R Work in Kitchen Yes No 0.0243 1.569* 1.052 2 .340

Note : Shaded area (and asterisk) indicates statistically significant results .

(a) See Table 3-11 for variable definitions .

(b) "Number of Rooms" was included as an ordinal variable . The risk groups were chosen for illustration. More generally, the odds ratio between n+k and n rooms is 1 .119k .

44

~~
p. 55

Table 3-13 . Conditional Odds Ratios from Logistic Regressions with Single R&R Variables

(and Any Other R&R Variables Nesting Them)

Confidence

Variable ° Hi her Risk Lower Risk P-Value Odds Ratio Interval

Any R&R Work Yes No 0.0220 1.309* ( 1 .035,1 .656)

Inside Painting Yes No 0.9267 1.010 (0.814,1 .252)

Window Repair or Yes No 0.4652 1.095 ( 0 .855,1 .402)

Replacement

Inside or Outside Paintin Yes No 0 .0116 1.322* (1,060.1-64911

Prepared Surface b Yes No 0.0152 1.383* ( 1 .059,1 .806)

Prepared Surface for Inside Yes No 0.0349 1.419* ( 1 .018,1 .976)

Paintin `

Hand Sanding or Scraping d No Yes 0.0085 2.385* ( 1 .232,4 .614)

Power Sandinp, Grinding, Yes No 0.8079 1.055 (0.678,1 .643)

Sandblasting

Open Flame Torch d Yes No 0.0280 3.870* ( 1 .129,13.264)

Heat Gun ° Yes No 0.0000 4 .091 (2.345,7 .137)

Washing, Wetsdcraping, Yes No 0.2101 1 .313 (0.850,2 .029)

Water Blasting

Chemical Paint Removers d Yes No 0.0507 1 .654 (0.988,2 .769)

Who Did the Work ?

Head of the Household or No Yes 0 .1132 1 .439 ( 0.909,2 .279)

Spouse d

Other in Household d No Yes 0.0065 4.160* (1.460,11 .853)

Relative or Friend Not in Yes No 0 .0250 1 .831* ( 1 .067,3 .141)

Household d

Owner or Apa rtment Staff d No Yes 0.8726 1 .053 (0.553,2 .004)

Professional d Yes No 0.5364 1 .184 (0.686,2 .041)

Lived in Home While R&R No Yes 0 .8720 1 .049 (0.577,1 .907)

Was Done °

Number of Rooms ° 1` 0 f 0.0023 1 .178* ( 1 .058,1 .311)

R&R Work in Kitchen 8 Yes No 0.1668 1 .470 (0.8422

.56

8

Note : Shaded area (and asteri sk) indicates statistically signi ficant results .

(a) See Table 3-11 for variable de fi nitions .

(b) Odds ratio conditional on Any R&R Work" = 'Yes' .

(c) Odds ratio conditional on "Inside Pain ti ng" = 'Yes'.

(d) Odds ratio conditional on "Prepared Surface" ='Yes' .

(e) Odds ratio conditional on "Prepared Surface for Inside Painting" = 'Yes' .

(f) "Number of Rooms" was included as an ordinal vari able . The risk groups were chosen for illustration .

More generally, the odds ratio between n+k and n rooms is 1 .178k.

45 66
p. 56

which adds a single R&R variable and any other R&R variables nesting that particular variable

to the baseline model . (Recall that, a variable is said to "nest" another if the value of the former

restricts the value of the latter. In the case of R&R variables, "nesting" occurs due to the skip

patterns in the questionnaire, where the response to one R&R question can determine whether

another question is skipped.) By including these nested R&R variables, the models are taking

the skip patterns into account. The odds ratio in this set of models compares the odds of a child

having an EBL when a R&R event occurred against the odds of a child having an EBL when

some alternative R&R activity (or activities) occurred instead . To illustrate, take the case in

which "Open Flame Torch" and all the R&R variables that nest it ("Any R&R Work" and

"Prepared Surface") were included as explanatory variables. The skip pattern in the

questionnaire ensured that only those respondents who answered "Yes" to "Any R&R Work"

and "Prepared Surface" could answer the question concerning whether they used an open flame

torch. The odds ratio therefore compares the odds of a child having elevated blood-lead

concentrations when an open flame torch was used to prepare the surface against the odds of a

child having elevated blood-lead concentrations when some method(s) other than an open flame

torch was (were) used instead to prepare the surface . Alternatively, the "Open Flame Torch"

odds ratio could be interpreted as comparing the risk of using an open flame torch against not

using an open flame torch, given that at least some form of surface preparation was carried out .

This explains the use of "conditional" to describe the odds ratios from the third set of models .

The results in Table 3-13 are fairly consistent with the results in Table 3-12 . In

Table 3-13, the odds of an EBL were significantly higher by a factor of 1 .419 if the surface was

prepared for inside painting, given that some inside painting was carried out ; but in Table 3-12

the unconditional odds for the same variable bordered on insignificant . The unconditional odds

ratio for "Hand Sanding or Scraping" in Table 3-12 (1 .226) is insignificant but much lower than

the unconditional odds ratio for "Prepared Surface" (1 .430). This explains the difference in the

conditional odds ratios of Table 3-13, where the odds are significantly lower if hand sanding or

scraping is carried out, given that the surface is prepared. Note that the results for the first

four rows are the same for Tables 3-12 and 3-13 since the R&R variables in those rows are not

nested by any other R&R variables.

Table 3-14 lists the p-values of the estimated coefficients, the odds ratios, and the

confidence intervals of the odds ratios for all the R&R variables from the model created by

including all the R&R variables from Table 3-11 as additional explanatory variables in the

baseline model and eliminating the insignificant R&R variables using stepwise backward

elimination. The backward elimination was restricted so that only those R&R variables that did

not nest another significant R&R variable could be eliminated at each step .

Note that some insignificant R&R variables were retained in the final model due to the

restriction in the backward elimination that accounted for the skip patterns . The final model is

fairly consistent with the results from the previous two sets of models with single R&R variables .

"Any R&R Work," which was significant in the analysis of single R&R variables, becomes

insignificant, probably due to including the two painting variables that are closely associated

with the variable . The significance of "Inside Painting" lowering the risk is misleading since the

effect is negated by the "Inside or Outside Painting" variable . "Prepared Surface for Inside

Painting" is insignificant probably due to its close association with "Prepared Surface . "

46
p. 57

Table 3-14. Conditional Odds Ratios from Logistic Regression with Multiple R& R

Variables

Confidence

Variable' Hi her Risk Lower Risk P-Value Odds Ratio Inte rva I

Any R&R Work Yes No 0.8518 1.039 (0.690,1 .565)

Inside Painting No Yes <0.0001 2.432* (1.605,3 .685)

Inside or Outside Painting Yes No 0.0005 2.517* 1 .484 4 .268

Prepared Su rface

b Yes No 0.0099 2.537* (1 .232,5 .224)

Prepared Surface for Inside No Yes 0.1189 1.629 (0.871,3 .048)

Painting 0-

Hand Sanding or Scraping d No Yes 0.0026 2.795* (1 .411,5 .538)

Heat Gun d Yes No 0.0001 4.138* (2.269,7 .548)

Other in Household d No Yes 0.0060 4.456* (1.502,13.225)

Relative or Friend Not in Yes No 0.0028 2.339* (1.324,4 .131)

Household °

Number of Rooms e 1

f 0 f 0.0014 1.194* (1 .069.1 .334)

Note : Shaded area (and asterisk) indicate statistically significant results .

(a) See Table 3-11 for variable definitions .

(b) Odds ratio conditional on "Any R&R Work" ='Yes' .

(c) Odds ratio conditional on "Inside Painting" = 'Yes' .

(d) Odds ratio conditional on "Prepared Surface" ='Yes' .

(e) Odds ratio conditional on "Prepared Surface for Inside Painting" ='Yes' .

(f) "Number of Rooms" was included as an ordinal variable. The risk groups were chosen for illustration .

More generally, the odds ratio between n+k and n rooms is 1 .194k .

The surprising result that was consistent across all the multivariate models is that the odds

of a child having an elevated blood-lead concentration is significantly lower if the surface

preparation was carried out by someone in the household other than the head of household or

spouse. Compared to professionals who had (insignificantly) higher odds, the non-head-ofhouseholds might be expected to be less careful about the spread of lead from R&R work . There

was some concern that the unexpected results obtained for work done by some household

member other than the head of household may be due to the type of R&R activity performed or

the size of the job. Table 3-15 presents information on the number and percentage of specific

R&R activities performed by various types of individuals.

Based on Table 3-15, it can be concluded that all types of individuals use the various R&R

techniques considered with similar frequencies . It appears that professionals and owners

undertake larger jobs than those living in the household and relatives and that different sized jobs

are tackled by different methods. However, since the odds ratio in the final model with multiple

R&R variables accounts for the differences in the number of rooms, there is no obvious

indication of why work performed by a household member other than the head of household (or

spouse) should decrease the odds of an elevated blood level concentration. No conclusive

resolution to this counter-intuitive result could be produced.

47

57
p. 58

Table 3-15 . Breakdown of Type of Specific R&R Activity by Type of Individual Who Did

Work

Who Did the Work

Head of Relative or Owner or

Household Other in Friend not in Apartment

or Spouse Household Household Staff Professional Number o

R&R Activity (n=488) n=69 n=71 n=52 (n=701 I Rooms

Any R&R Worka 488 69 71 52 70 2. 8

(100%) (100%) (100%) (100%) (100%)

Inside Painting' 417 59 59 31 60 2.9

(85%) (86%) (83%) (60%) (86%)

Window Repair or 169 28 30 17 36 3.2

Replacementa (35%) (41%) (42%) (33%) (51%)

Inside or Outside Paintinga 469 63 68 51 69 2. 9

(96%) (91%) (96%) (98%) 99%

Prepared Surfaceb 488 69 71 52 70 2.9

(100%) (100%) (100%) (100%) (100%)

Prepares Surface for Inside 281 49 47 18 33 2.9

Paintin ° (67%) (93%) (80%) (58%) (55%)

Hand Sanding or Scraping° 461 65 68 47 64 2.9

(94%) (94%) (96%) (90%) (91 %)

Power Sanding, Grinding, 146 23 35 10 24 3.4

or Blasting° (30%) (33%) (49%) (19%) (34% )

Open Flame Torch d 6 - - - 4 5.3

(1 %) (6%)

Heat Gun° 43 3 5 3 5 3.5

(9%) (4%) (7%) (6%) (7%)

Washing, Wetsdcraping, 160 25 27 7 17 3.2

Water Blasting (33%) (36%) (38%) (13%) (24% )

Chemical Paint Removers d 80 13 13 6 10 4.2

(16%) (19%) (18%) (12%) (14%)

Liveddin Home While R&R 452 64 59 40 59 2.8

Done (93%) (93%) (83%) (77%) (84%)

Number of Rooms 2.9 3 .4 3.3 4.3 3. 6

a. Percentage in parentheses is in rela tion to n in column labels .

b. Percentage in parentheses is in relation to frequency in "R&R Work" row .

c . Percentage in parentheses is in rela ti on to frequency in "Inside Painting" row .

d . Percentage in parenth eses is in relation to frequency in "Prepared Surface" row.

For the final set of models, a single interaction between each R&R variable and an age of

house variable was included as an additional explanatory variables in the baseline model. The

significance of the interactions was examined in an attempt to identify differences in risk due to

48

'e--ey
p. 59

lead exposure between R&R activities performed in pre- and post-1980 homes . When the age of

house variable was defined as either pre- or -post-1980, the interaction term in all the models

were insignificant. Hence, the available data did not provide any evidence that the 1978 ban on

lead-based paint affected the odds of elevated blood-lead concentrations in children as a result of

R&R activities. Similar analysis using a three-level age of house variable (pre-1960, 1960-1980,

and post-1980) produced the same results . There are many possible reasons for this finding:

1 . Age of residence was an interview reported variable, and, thus, may have been

reported inaccurately for some homes.

2 . Only the manufacturing of lead-based paint was banned in 1978 . Residences may

have been painted with lead-based paint using old paint.

3. R&R activities in residences may increase risk due to childhood lead exposure by

stirring up lead-contaminated dust from sources other than lead-based paint.

3.3 .3 Statistical Results

Although medical assistance status was a design variable in this study, it was not treated

as such in the analysis of the data. Table 3-1 indicates the univariate relationship between

medical assistance status and odds of an elevated blood-lead concentration . This relationship is

not statistically significant . Medical assistance status is, however, a significant factor in the

multivariate baseline logistic regression model . Its inclusion in this model accounts for the effect

of medical assistance status in the multivariate analysis. In preliminary analysis, univariate

regression results were calculated separately for children receiving medical assistance and

children not receiving medical assistance, as might normally be done for a design variable . The

results (the effects of other demographic and R&R variables on odds of an elevated blood-lead

concentration) were similar for both medical assistance statuses ; and, thus, a decision was made

to pool the data across medical assistance status. The fact that medical assistance status was

accounted for in the multivariate model is one reason for preferring the results based on the

multivariate analysis to the univariate results .

The multivariate results reported are based on the statistical significance of composite

R&R activity variables when introduced into a baseline logistic regression model . The

composite R&R variables were constructed from responses to multiple interview questions . The

baseline model accounted for the effects of a number of housing factors, demographics, and other

lead exposures. This approach identified more statistically significant effects than univariate

analysis of individual question responses (Section 3 .3 .1) for two reasons:

1 . Variability due to other known lead exposure factors was reduced by using a baseline

model when assessing the impact of an R&R activity .

2. The overall incidence of the composite R&R activity variables was higher. This

makes it easier to assess the effect of a variable on the odds of an elevated blood-lead

concentration.

49~
p. 60

The analysis documented in this report demonstrated a statistically significant

relationship between R&R activities and the odds of elevated blood-lead concentrations .

Specifically, children residing in residences in which some R&R activity was conducted in the

last 12 months were estimated to have odds of an elevated blood-lead concentration 1 .3 times

greater than children residing in residences where no R&R was conducted . One reason for this

increase in odds appeared to be due to the significant increase in odds in residences where

outside painting was carried out . When paint removal using a heat gun was performed at a

residence, the odds of an elevated blood-lead concentration were highly significant (4 .6 times

greater) than if the work was not performed . (The odds were over 4 times greater when

compared to the case when some other type of surface preparation was carried out and to the case

when the effects of other R&R factors were taken into account) . Conversely, hand sanding and

scraping appeared to have significantly smaller odds given that some alternative form of surface

preparation was carried out . Increasing the number of rooms in which surface preparation was

carried out for inside painting also increased the risk of EBL in children . Finally, a relative or

friend not in the household increased the risk of elevated blood-lead concentrations in children

significantly, possibly due to the lack of care taken in preventing the spread of lead in the house

during the R&R activities. The significant and unexpected reduction in odds when someone in

the household other than the head or spouse carried out the R&R activity could not be explained .

50 /

ou
p. 61

4.0 CONCLUSIONS

This study demonstrated that general residential R&R is associated with an increased risk

of EBLs in children and that specific R&R activities are also associated with an increase in the

risk of EBLs in children . In particular, removing paint (using open flame torches, using heat

guns, using chemical paint removers, and wet scraping/sanding) and preparing surfaces by

sanding or scraping significantly increased the risk of EBLs . Overall, these results agree with

those from earlier phases of the R&R Study-R&R activities that disturb lead-based paint

increase the risk of exposure to occupants . Additionally, children living in a residence while

R&R was conducted were 1 .3 times more likely to have EBLs than children who did not live in a

residence while R&R was conducted .

The study also characterized the exposure of residents to R&R activities. At least one

R&R activity such as inside painting, outside painting, carpet and floor repair or replacement, or

other repairs (e.g., window repair) had been conducted in 67 .2 percent of the study residences in

the previous 12 months. Some form of surface preparation was involved in 42.3 percent of R&R

activities. Most surface preparation involved hand scraping or sanding . Heat guns were used for

surface preparation 7 percent of the time, and chemical paint removers were used 13 .6 percent of

the time.

The results of this study point toward a continuing need to educate parents and guardians

about avoiding more risky R&R activities. Parents or guardians also could be educated about the

positive benefits of relocation while R&R is being performed in a residence .

Further, the study has identified specific R&R activities and other conditions (such as age

and type of residence) that are associated with increased risk to children as a result of lead

exposure. This information can be used to develop regulations that focus on particular R&R

activities (e.g., using a heat gun to remove paint), the groups of persons (e .g., a household

member other than the head of household or spouse) who perform the activities, and the other

conditions (e.g., adult exposure, age of child) that significantly increase the risk to children. The

results of this study concerning activities associated with increased risk (e .g., using a heat gun to

remove paint) also can be combined with the worker profile results from other phases of the

R&R study to perform an overall assessment of the worker groups or situations where

interventions are needed to reduce exposure from R&R .

51 (0/
p. 62

5 .0 REFERENCES

Bornschein, R. L., Succop, P. A., Dietrich, R. N., Clark, C . S ., Que Hee, S ., and Hammond, P.B .,

(1985) "The Influence of Social and Environmental Factors on Dust Lead, Hand Lead, and

Blood-Lead Levels in Young Children ." Environmental Research 38:108-118.

Brody, D . J., Pirkle, J . L., Kramer, R. A., Flegal, K. M ., Matte, T. D., Gunter, E. W., and

Paschal, D. C., (1994) "Blood-Lead Levels in the US Population : Phase I of the Third National

Health and Nutritional Examination Survey (NHANES III, 1988 to 1991)." Journal of the

American Medical Association 272(4) :277-283.

CDC (see Centers for Disease Control)

Centers for Disease Control (1991) "Preventing Lead Poisoning in Young Children : A

Statement by the Centers for Disease Control ." Public Health Service, Centers for Disease

Control and Prevention, U.S . Department of Health and Human Services, October 1991 .

Centers for Disease Control (1994) "Plan and Operation of the Third National Health and

Nutrition Examination Survey, 1988-94 ." National Center for Health Statistics, Centers for

Disease Control and Prevention, U .S . Department of Health and Human Services, DHHS

Publication No. (PHS), 94-1308 .

EPA (see U.S . Environmental Protection Agency)

Groves, R. M., Bieme, P. B ., Lyberg, L. E., Massy, J . T., Nicholls, W. L., Waksberg, J., (1988)

Telephone Survey Methodology . John Wiley & Sons, New York .

Holm, Sture (1979) "A Simple Sequentially Rejective Multiple Test Procedure ." Scandinavian

Journal of Statistics, 6, 65-70.

Lanphear, B. P., Weitzman, M ., Winter, N. L., Eberly, S ., Yakir, B ., Tanner, M ., Emond, M., and

Matte, T. D., (1996b) "Lead-Contaminated House Dust and Urban Children's Blood-Lead

Levels." American Journal of Public Health 86 (10) :1416-1421 .

McCullough, P ., and Nelder, J. A., (1989) Generalized Linear Models . Chapman and Hall,

London.

Neter, J., and Wasserman, W ., (1974) Applied Linear Statistical Models, Homewood, IL:

Richard D. Irwin, Inc.

Savitz and Olshan (1995) "Multiple Comparisons and Related Issues in the Interpretation of

Epidemiologic Data ." American Journal of Epidemiology 142( 9) .

Thompson, S ., (1992) Samplin~. John Wiley & Sons.

52

4~J 2 .
p. 63

U.S. Environmental Protection Agency (1994) "Reducing Lead Hazards When Remodelin g

Your Home ." Office of Pollution Prevention and Toxics, U.S. Environmental Protection

Agency, EPA 747-R-94-002, April 1994.

U.S . Environmental Protection Agency (1995) "Seasonal Rhythms of Blood-Lead Levels ."

Office of Pollution Prevention and Toxics, U.S . Environmental Protection Agency, EPA 747-R94-003, September 1995 .

U.S . Environmental Protection Agency (1996) "Seasonal Trends in Blood-Lead Levels in

Milwaukee." Office of Pollution Prevention and Toxics, U.S . Environmental Protection Agency,

EPA 747-R-95-010, August 1996 .

U.S. Environmental Protection Agency (1997a) "Lead Exposure Associated With Renovation

and Remodeling Activities : Summary Report." Office of Pollution Prevention and Toxics,

U.S . Environmental Protection Agency, EPA 747-R-96-005, May 1997 .

U.S . Environmental Protection Agency (1997b) "Lead Exposure Associated With Renovation

and Remodeling Activities: Environmental Field Sampling Study." Office of Pollution

Prevention and Toxics, U.S. Environmental Protection Agency, EPA 747-R-96-007, May 1997 .

U.S . Environmental Protection Agency (1997c) "Lead Exposure Associated With Renovation

and Remodeling Activities : Worker Characterization and Blood-Lead Study ." Office of

Pollution Prevention and Toxics, U .S . Environmental Protection Agency, EPA 747-R-96-006,

May 1997.

U.S. Environmental Protection Agency (1997) "Lead Exposure Associated With Renovation and

Remodeling Activities: Phase IV, Worker Characterization and Blood-Lead Study of R&R

Workers Who Specialize in Renovation of Old or Historic Buildings ." Office of Pollution

Prevention and Toxics, U.S . Environmental Protection Agency, Draft Final Report ,

January 29, 1998 .

U.S. Department of Housing and Urban Development (1995) "Guidelines for the Evaluation and

Control of Lead-Based Paint Hazards in Housing ." Office of Lead-Based Paint Abatement and

Poisoning Prevention .

53

63

,
p. 64

This page intentionally blank.

54
p. 65

APPENDIX A:

EXPLORATORY ANALYSIS OF WISCONSIN CHILDHOOD

BLOOD-LEAD STUDY QUESTIONNAIRE DAT A

A-1
p. 66

Exploratory Analysis of Wisconsin Childhood Blood-lea d

Study Questionnaire Data

Skip Pattern s

To save time during the telephone interviews, groups of questions regarding a particular R&R

activity were skipped if the response to the first question was negative (see Section 3 .1 .3) . The

table on the next page shows the pattern of skipping questions .

Most of the questions concerning R&R activities were introduced with the phrase "In the last 12

months. . . ." as in the first cell of the table on the next page . Reading across the table gives the

type of R&R activity that fills in the blank for the question number indicated in parentheses .

The first column gives the specific question, and the two columns below each activity type

specify the question number and who answered the question .

For example, for "any painting or surfaces prepared for paint INSIDE home?," the second

column indicates that this is question 10, and column three indicates that everyone answered that

question. Further down the first column, for the question "surface prepared by sanding/scraping .

. .?," column two indicates that this is question 13, and column three indicates that anyone who

answered "Yes" to question 10 answered question 13 . Likewise for the question

"Handsanding/handscraping used?" (question 14), anyone who answered "Yes" to question 13

answered question 14 . This pattern can be followed down the table for a specific R&R activity

and across the table for types of R&R activities.

A-2 66
p. 67

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A-3

17
p. 68

HOUSING

Ql: First, I would like to ask you some questions about your housing. Do you own or rent

your home?

1 . RENTING

2 . OWN

3 . FEE FREE'

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead Log-Odds Ratio

Concentratio n

7 s PbB

Response PbB <7 < 10 PbB z 10 Geometric

Category I~g/dL Geometric Standard

~rg/dL JU g/dL Mean Standard Estimate Error P-value

Deviation

1 1245 169 141 2.67 2.67

2 1719 188 139 2.30 2.66 -0.34 0.13 0.0062

3 21 5 7 3.61 2.57 1.08 0.45 0.0147

8 13 3 2 3.78 2.9 7

1 1 0 5.92 1 .1 8

*"Fee free" means the respondent and child live free (no rent). For example, they live with grandparents.

A-4

i~~
p. 69

Ql a: What kind of building do you live in now? Is it a single family home, a duplex, an

apartment or condominium with 4 or fewer units, an apartment or condominium with 5

or more units, or a mobile home or trailer?

1 . SINGLE FAMILY HOME

2 . DUPLEX

3 . APARTMENT/CONDOMINIUM WITH 4 OR FEWER UNITS

4. APARTMENT/CONDOMINIUM WITH 5 OR MORE UNITS

5. MOBILE HOME OR TRAILER

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log Odds Ratio

Response PbB <7 7 s Pb B

< 10 PbB z 10 Geometric Category pg/dL jig/dL Geometric Standard

Ng/dL Mean Standard Estimate Error P-value

Deviation

1 2327 268 187 2.35 2.64

2 457 54 56 2.53 2.74 0.42 0.16 0.0087

3 200 41 42 3.78 2.36 0.96 0.19 0.0001

. 15 3 0 4.18 1.5 6

Q2: About what year was your residence built? (If you don't know for sure, please guess in

which decade it was built.)

ENTER COMPLETE YEAR, E.G. 1888, d OR r

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category Ng/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

Pre 1940 1048 154 123 2.95 2.49

1940-49 162 16 13 2.11 2.63 -0.38 0.30 0.2105

1950-59 181 25 15 2.26 2.79 -0.35 0.29 0.2222

1960-69 179 24 14 2.56 2.53 -0 .41 0.29 0.1666

1970-79 398 41 21 2.25 2.49 -0.80 0.24 0.001 0

Post 1980 638 41 29 1 .70 2.81 -0.95 0.21 0.0001

393 65 70 3.02 2.6 9

A-54o
p. 70

Q3: Has {Ol} lived in your current home longer than 12 months? (If no, then all questions

apply to current home as well as any other one lived in during the past year .)

1 . YES

2. NO

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category Ng/dL pg/dL Ng/dL Mean Deviation Estimate Error P-value

1 2371 258 210 2.36 2.66

2 627 108 74 2.96 2.53 0.29 0.14 0.0439

1 0 1 4.79 2.73

Q4: In what moth and year did your family move into your current home?

ENTER MONTH AND YEAR E .G . 11/85

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category /ug/dL /jg/dL Ng/dL Mean Deviation Estimate Error P-value

Pre 1980 83 11 7 2.92 2.1 6

1980-1989 399 35 42 2.00 3.02 0.22 0.43 0.6026

1990 166 8 14 1.96 2.86 -0 .00 0.48 1 .0000

1991 178 16 8 2.05 2.54 -0.63 0.53 0.2388

1992 208 25 14 2.22 2.63 -0.23 0.48 0.6390

1993 305 39 27 2.57 2.57 0.05 0.44 0.9127

1994 408 51 36 2 .69 2.47 0.05 0.43 0.9164

1995 574 58 53 2.33 2.68 0.09 0.42 0.8288

1996 627 108 74 2.98 2.54 0.34 0.41 0.4151

1997 29 9 3 3.28 2 .45 0.20 0.72 0.7776

22 6 7 3.29 2.94

A-6
p. 71

Q4b: What kind of building do you live in before your current residence ?

1 . SINGLE FAMILY HOME

2. DUPLEX

3 . APARTMENT/CONDOMINIUM WITH 4 OR FEWER UNITS

4. APARTMENT/CONDOMINIUM WITH 5 OR MORE UNITS

5 . MOBILE HOME OR TRAILER

8 . DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category Ng/dL Ng/dL pg/dL Mean Deviation Estimate Error P-value

1 283 42 28 2.82 2.50

2 106 20 19 3.24 2.73 0.59 0.32 0.0619

3 76 13 14 3.79 2.21 0.62 0.35 0.0773

4 106 18 8 2.47 2.58 -0.27 0.42 0.5159

5 55 13 3 2.77 2.52 -0.60 0.63 0.3408

8 0 2 0 8.00 1.00

2373 258 213 2.36 2.6 7

Q4c: In what year was your previous residence build?(If you don 't know forsure, please guess

in which decade it was built)

ENTER COMPLETE YEAR, E .G. 1888. D or R

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category Ng/dL Ng/dL ug/dL Mean Deviation Estimate Error P-value

Pre 1940 190 35 24 3.26 2.46

1940-49 28 4 7 2.76 3.21 0.68 0.47 0.1505

1950-59 38 7 4 2.50 2.76 -0 .18 0.57 0.7485

1960-69 41 5 5 1.78 3.91 -0 .04 0.52 0.9462

1970-79 82 17 5 2.21 2.76 -0 .73 0.51 0.1525

Post 1980 105 17 4 3.12 1.95 -1 .20 0.55 0.0304

refused 5 0 2 3.54 3.00

2510 281 234 2.42 2.65

A-7

7

/
p. 72

QS: Does (tested child) live in your household most of the time ?

1 . YES

2. NO

3 . ALL OF THE TIME (VOL)'

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category /rg/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 2565 309 234 2.50 2.60

2 23 0 3 1.25 3.96 0.36 0.62 0.5627

3 408 57 48 2.47 2.80 0.25 0.17 0.1282

3 0 0 T 2 .76 1.0 5

Q6 : Would you say that there is no or very little peeling paint, some peeling paint or a lot of

peeling paint inside your home .

1 . NONE OR VERY LITTLE PEELING PAINT (surface intact)

2 . SOME PEELING PAINT (less than 2 sq ft)

3 . A LOT OF PEELING PAINT (involves than 2 sq ft)

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category Ng/dL Ng/dL /jg/dL Mean Deviation Estimate Error P-value

1 2537 288 219 2 .33 2.7 0

2 353 64 46 3 .05 2.56 0.41 0.17 0.0312

3 104 14 24 3.92 2.37 0.98 0.24 0.0001

5 0 0 2.76 1.05

*"(Vol)" indicates that this response was volunteered and was not originally listed as a response to the question .

A-8
p. 73

Q7: Would you say that there is no or very little peeling paint, some peeling paint or a lot of

peeling paint on the outside of your home.

1 . NONE OR VERY LITTLE PEELING PAINT (surface intact)

2. SOME PEELING PAINT (less than 2 sq ft)

3 . A LOT OF PEELING PAINT (involves more than 2 sq ft)

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category Ng/dL Ng/dL pg/dL Mean Deviation Estimate Error P-value

1 2327 268 190 2.33 2.69

2 457 54 57 2.50 2.80 0.42 0.16 0.0079

3 200 41 42 3.78 2.36 0.94 0.19 0.0001

15 3 0 4.18 1.5 6

A-9
p. 74

INSIDE PAINTING

We are trying to learn what people are doing to keep up their homes or to make major changes

to them. First, I would like to start by asking you about any work that has been done or is being

done inside your home or apartment.

Q10: During the past 12 months, was there any painting or were any surfaces prepared for

paint inside your home ?

1 . YES

2. NO

8. DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometri c

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category pg/dL Ng/dL /i

g/dL Mean Deviation Estimate Error P-value

1 1 181 163 121 2.65 2.6 1

2 1810 203 162 2.39 2.64 -0.14 0.13 0.2828

8 8 0 2 0.88 6.62

Q11 : Was any work done to repair broken plaster or damaged walls in the room/rooms you

painted in the last 12 months ?

1 . YES

2 . NO

8 . DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category Ng/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 635 101 74 2.93 2.49

2 2353 265 209 2.36 2.68 -0.27 0.14 0.0566

8 10 0 2 2.62 2.87

1 0 0 2.76 1.05

A-10
p. 75

Q12: Was any work done where old walls were taken down or moved, while working in your

home?

1 . YES

2 . NO

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category Ng/dL pg/dL ug/dL Mean Deviation Estimate Error P-value

1 279 48 33 2.92 2.47

2 2717 317 249 2.43 2.65 -0.26 0.20 0.1922

8 3 1 3 6.84 2.01

ASK Q's 13 THROUGH 27 IF INSIDE OF HOME WAS PAINTED .

Q13: Was the surface prepared for the new paint, by methods such as sanding or scraping off

the old paint ?

1 . YES

2 . NO

8. DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB i 10 Geometric Standard Standard

Category Ng/dL Ng/dL /rg/dL Mean Deviation Estimate Error P-value

1 412 76 53 3.26 2.44

2 1023 129 89 2.31 2.76 -0.35 0.16 0.0309

8 65 4 7 2.32 2.90

1499 157 140 2.34 2.69

`Log-odds ratios were calculated assuming that missing values were ' No' response because people who didn't

do this R&R activity were not asked this question .

A-11

7S
p. 76

How was the surface prepared for the new paint ?

Q14: Was hand scraping or hand sanding used?

1 . YES

2. NO

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category pg/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 374 68 40 3.19 2.35

2 27 7 8 4.25 2.69 -0.14 0.18 0.4479

8 11 1 5 4.59 2.83

2587 290 236 2 .33 2.72

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

Q1 S: Was power sanding, grinding, or sandblasting used?

1 . YES

2. NO

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category pg/dL Ng/dL pg/dL Mean Deviation Estimate Error P-value

1 128 22 16 3.20 2.56

2 270 51 35 3.29 2.39 -0.28 0.27 0.3115

8 14 3 2 3.51 2.30

2587 290 236 2.33 2.72

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

A-12

7~
p. 77

Q16: Was an open flame torch used ?

1 . YES

2. NO

8 . DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Catego ry /rg/dL pg/dL Ng/dL Mean Deviation Estimate Error P-value

1 2 3 1 6.05 1.79

2 399 71 49 3.23 2.44 -1 .66 1 .23 0.1769

8 11 2 3 3.62 2.64

2587 290 236 2 .33 2.72

"Log-odds ratios were calculated assuming that missing values were ' No' response because people who didn't

do this R&R activity were not asked this question .

Q17: Were heat guns used?

1 . YES

2. NO

8. DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category Ng/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

1 28 7 9 4.40 2.92

2 370 67 39 3 .17 2.34 - 1 .24 0.39 0.0014

8 14 2 5 4.86 2.41

-1 2587 290 236 2.33 2.7 2

'Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

A-13

7;7
p. 78

Q18: Was washing, wet scraping, wet sanding, or water blasting used ?

1 . YES

2. NO

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category Ng/dL pg/dL Ng/dL Mean Deviation Estimate Error P-value

1 119 24 17 3.55 2.29

2 269 49 34 3.19 2.51 -0.41 0.27 0.1220

8 24 3 2 2.68 2.34

2587 290 236 2.33 2.72

"Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

Q19: Were chemical paint removers used?

1 . YES

2 . NO

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category pg/dL ug/dL Ng/dL Mean Deviation Estimate Error P-value

1 70 14 12 3.83 2.48

2 331 60 37 3.13 2.39 -0.61 0.32 0.0575

8 11 2 4 4.54 2.65

2587 290 236 2.33 2.72

`Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

A-14%r7
p. 79

Q20: Who did the work?

1 . HEAD OR SPOUSE

2. OTHER PERSON IN HH

3. RELATIVE/FRIEND NOT IN HH

4

. OWNER, BUILDING SUPERINTENDENT, APT STAFF

5 . PAID PROFESSIONAL CONTRACTOR

ENTER ALL THAT APPLY SEPARATED BY SLASHES, d OR r, a FOR ALL

(FOR EACH ITEM, THE ANSWER WILL BE :

1 . YES

2 . NO

8 . DON'T KNOW

1 9

. REFUSED)

.

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category Ng/dL /

Jg/dL Ng/dL Mean Deviation Estimate Error P-value

1 324 61 36 3.20 2.4 1

2 87 15 17 3.56 2.49 -0.16 0.19 0.3916

8 1 0 0 2.76 1.0 5

2587 290 236 2 .33 2.7 2

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

2.

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category pg/dL pg/dL /i

g/dL Mean Deviation Estimate Error P-value

1 63 8 5 2.96 2.33

2 348 68 48 3.33 2.45 0.20 0.47 0.6724

8 1 0 0 2.76 1.05

2587 290 236 2.33 2.72

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

A-15

1V
p. 80

3 .

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category Ng/dL /ig/dL Ng/dL Mean Deviation Estimate Error P-value

1 48 11 8 3.64 2.26

2 363 65 45 3.22 2.46 -0.56 0.39 0.1482

8 1 0 0 2.76 1.05

r- i 2587 290 236 2.33 2.7 2

"Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

4 .

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category /rg/dL Ng/dL pg/dL Mean Deviation Estimate Error P-value

1 39 8 7 3.48 2.48

2 372 68 46 3.25 2.43 -0.63 0.42 0.1273

8 1 0 0 2.76 1.0 5

2587 290 236 2.33 2.72

"Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question.

5 .

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB 2: 10 Geometric Standard Standard

Category Ng/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 42 4 5 2.21 3.1 0

2 369 72 48 3.37 2.39 -0.21 0.48 0.6532

8 1 0 0 2.76 1.05

2587 290 236 2.33 2.72

"Log-odds ratios were calculated assuming that missing values were ' No' response because people who didn't

do this R&R activity were not asked this question .

A-16~~
p. 81

Q21: When was this job started and when was it completed? (If more than one job was done,

then record the start of the first job and the end of the last one )

ENTER MONTH AND YEAR FOR EACH ON SEPARATE LINES d OR r

ENTER n FOR COMPLETION DATE IF WORK IS STILL IN PROGRESS

Q22: Did anyone in your household live in the home while the work was being done?

1 . YES

2. NO

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category Ng/dL pg/dL Ng/dL Mean Deviation Estimate Error P-value

1 351 64 43 3.30 2.38

2 61 12 10 3.07 2.77 -0.28 0.17 0.1135

2587 290 236 2 .33 2.72

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

Q23: In how many rooms in your home was this work done?

ENTER NUMBER OF ROOMS d OR r OR 0 FOR NONE

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category pg/dL kg/dL pg/dL Mean Deviation Estimate Error P-value

1 161 31 13 3.20 2.1 9

2 94 13 12 2.80 2.72 0.46 0.42 0.2764

3 55 9 3 3.15 2.32 -0.39 0.66 0.5518

=>4 98 18 25 3.87 2.56 1.15 0.37 0.0016

None 0 1 0 7.00 1.00 0.12 0.30 0.6842

2591 294 236 2.34 2.7 2

A-17^

../~j(1
p. 82

Q24: Was any of this work done in the kitchen ?

1 . YES

2 . NO

8 . DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category Ng/dL pg/dL Ng/dL Mean Deviation Estimate Error P-value

1 155 39 28 3.33 2.68

2 256 37 25 3 .24 2.26 -0.68 0.22 0.0017

8 1 0 0 5.00 1.00

2587 290 236 2.33 2.72

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

Q25: Was any of this work done in the bathroom?

1 . YES

2 . NO

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category Ng/dL jrg/dL Ng/dL Mean Deviation Estimate Error P-value

1 182 31 26 3.42 2.40

2 229 45 27 3.12 2.48 -0.43 0.22 0.0527

8 1 0 0 5.00 1.00

T

2587 290 236 2.33 2.7 2

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question.

A-18
p. 83

OUTSIDE PAINTING

Q28: During the past 12 months, was there any painting or were any surfaces prepared for

paint on the outside of your home ?

1 . YES

2 . NO

8 . DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category Ng/dL Ng/dL pg/dL Mean Deviation Estimate Error P-value

1 340 49 49 2.74 2.72

2 2640 313 232 2.45 2.62 -0.49 0.17 0.0031

8 19 4 4 3.55 2.57

Q29: Was the surface for this outside job prepared for the new paint, by methods such as

sanding or scraping off the old paint ?

1 . YES

2. NO

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category pg/dL Ng/dL /rg/dL Mean Deviation Estimate Error P-value

1 358 45 42 2.58 2.7 6

2 186 21 18 2.04 2.98 -0.23 0.18 0.1925

8 24 6 3 3.86 2.40

2431 294 226 2.47 2.65

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

A-19 ~~
p. 84

How was the surface prepared for the new paint ?

Q30: Was hand scraping or hand sanding used?

1 . YES

2. NO

8 . DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB ~ 10 Geometric Standard Standard

Category Ng/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 331 43 39 2.56 2.7 9

2 19 1 2 3.10 2.15 -0.23 0.18 0.2057

8 8 1 1 2.27 3.1 4

2641 321 247 2.46 2.66

"Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

Q31 : Was power sanding, grinding, or sandblasting used?

1 . YES

2. NO

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category Ng/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

1 47 8 9 3.30 2.3 8

2 294 35 30 2.40 2.87 -0 .71 0.37 0.0553

8 17 2 3 3.32 2.46

2641 321 247 2.46 2.66

"Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

A-20

~~
p. 85

Q32: Was an open flame torch used ?

1 . YES

2. NO

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB 2: 10 Geometric Standard Standard

Category pg/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

1 3 0 2 5.25 2.1 7

2 348 42 37 2.47 2.80 -1 .95 0.91 0.0332

8 7 3 3 5.33 1.98

2641 321 247 2.46 2.66

'Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

Q33: Were heat guns used?

1 . YES

2. NO

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category pg/dL p

g/dL pg/dL Mean Deviation Estimate Error P-value

1 14 1 9 4 .77 3.22

2 331 41 30 2.47 2.67 -1 .93 0.43 0.0001

8 13 3 3 4.03 2.20

2641 321 247 2.46 2.6 6

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

A-21 ~~
p. 86

Q34: Was washing, wet scraping, wet sanding, or water blasting used?

1 . YES

2 . NO

8 . DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category Ng/dL pg/dL Ng/dL Mean Deviation Estimate Error P-value

1 84 13 14 2.83 2.67

2 257 29 24 2.40 2.84 -0.58 0.30 0.0506

8 17 3 4 3.79 2.3 3

F_ 1 2641 321 247 2 .46 2.6 6

'Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

Q35: Were chemicalpaint removers used?

1 . YES

2 . NO

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category Ng/dL pg/dL Ng/dL Mean Deviation Estimate Error P-value

1 17 1 6 3.90 2.2 8

2 317 41 31 2.46 2.78 - 1 .32 0.48 0.0057

8 24 3 5 3.25 2.78

2641 321 247 2.46 2.66

'Log-odds ratios were calculated assuming that missing values were ' No' response because people who didn't

do this R&R activity were not asked this question .

A-22

~ ~~
p. 87

Q36: Who did the work?

1 . HEAD OR SPOUSE

2 . OTHER PERSON IN HH

3 . RELATIVE/FRIEND NOT IN HH

4. OWNER, BUILDING SUPERINTENDENT, APT STAFF

5 . PAID PROFESSIONAL CONTRACTOR

ENTER ALL THAT APPLY SEPARATED BY SLASHES, d OR r, a FOR ALL

(FOR EACH ITEM, THE ANSWER WILL BE:

1 . YES

2. NO

8. DON'T KNOW

9. REFUSED)

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB ;! 10 Geometric Standard Standard

Category Ng/dL /,rg/dL Ng/dL Mean Deviation Estimate Error P-value

1 246 30 29 2.56 2.7 5

2 108 14 13 2.67 2.79 -0.22 0.21 0.2868

8 4 1 0 2.07 2.2 8

2641 321 247 2.46 2.6 6

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

2.

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category /jg/dL pg/dL Ng/dL Mean Deviation Estimate Error P-value

1 32 2 2 1.30 3.6 9

2 322 42 40 2.70 2.71 0.44 0 .73 0.5492

8 4 1 0 2.07 2.28

2641 321 247 2.46 2.6 6

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

A-23
p. 88

3 .

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category pg/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 19 5 5 4.43 1.99

2 335 39 37 2.45 2.85 -1 .01 0.51 0.0452

8 4 1 0 2.07 2.28

2641 321 247 2.46 2.66

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

4.

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s Pb8 Geometric

Response PbB <7 < 10 PbB Z 10 Geometric Standard Standard

Category pg/dL Ng/dL ug/dL Mean Deviation Estimate Error P-value

1 59 6 8 2.62 2.87

2 295 38 34 2.59 2.74 -0.35 0.38 0.3617

8 4 1 0 2.07 2.28

2641 321 247 2.46 2.6 6

*Log-odds ratios were calculated assuming that missing values were ' No' response because people who didn't

do this R&R activity were not asked this question .

5 .

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB 2: 10 Geometric Standard Standar d

Category Ng/dL Ng/dL /jg/dL Mean Deviation Estimate Error P-value

1 41 5 7 2.64 3.0 1

2 313 39 35 2.59 2.72 -0.58 0.41 0.1599

8 4 1 0 2.07 2.2 8

2641 321 247 2.46 2.66

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

A-24
p. 89

Q37: When was this job started and when was it completed (If more than one job was done,

then record the beginning date of the first job and the ending date of the last one)?

ENTER MONTH AND YEAR FOR EACH ON SEPARATE LINES d OR r

ENTER n FOR COMPLETION DATE IF WORK IS STILL IN PROGRES S

Q38: Did anyone in your household live in the home while the work was being done?

1 . YES

2 . NO

8 . DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio*

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 Ng/dL pg/dL Ng/dL Mean Deviation Estimate Error P-value

1 339 43 41 2.54 2.8 1

2 19 2 1 3.32 1.90 -0.26 0.18 0.1442

2641 321 247 2.46 2.66

`Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

A-25 ~

t~
P. 90

OTHER REPAIRS

Next I would like to ask you about repairs and major changes to the rest of your home during the

past 12 months.

Q39: Were any windows repaired or new windows put in?

1 . YES

2. NO

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometri c

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 pg/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 528 86 65 3 .10 2.43

2 2466 278 217 2.34 2.68 -0.34 0.15 0.0245

8 5 2 3 4.64 2.7 8

Q40: Was any work done to repair broken plaster or damaged walls while repairing or putting

in the windows ?

1 . YES

2 . NO

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio'

7 s PbB Geometric

Response PbB < < 10 PbB ~ 10 Geometric Standard Standar d

Category 7 Ng/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 128 13 12 2.55 2.4 6

2 497 83 57 3.04 2.52 0 .02 0.31 0.9458

8 9 2 3 3.61 2.69

1

2365 268 217 2.33 2.7 2

`Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

A-26

._ . ._._ . ._ ..W.aw....~ ._ .~. ._ , ... _, .__
P. 91

Q41 : Was any work done where old walls were taken down or moved, while repairing or

putting in the windows ?

1 . YES

2. NO

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio*

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7,ug/dL jig/dL Ng/dL Mean Deviation Estimate Error P-value

1 90 10 9 2.64 2.73

2 540 87 64 2 .99 2.51 -0.04 0.36 0.9174

8 4 1 0 3.64 1.84

1

2365 268 216 2.33 2.7 2

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

Q42: Was there any painting or were any surfaces prepared for paint with the installation of

the new windows?

1 . YES

2 . NO

8 . DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio*

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 Ng/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 182 37 16 3.00 2.36

2 445 61 55 2.94 2.57 0.09 0.27 0.7301

8 7 0 2 3.30 3.69

23c S 268 216 2.33 2.72

*Log-odds ratios wer 3 calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity iere not asked this question .

A-27

71
p. 92

Q43: Did the window work involve preparing surfaces for paint, by methods such as sanding ,

scraping, using heat guns or the use of chemicals other than prime painting?

1 . YES

2 . NO

8 . DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio*

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standar d

Category 7 pg/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 96 19 10 2.96 2.42

2 502 72 56 2.91 2.53 -0.09 0.34 0.7823

8 36 7 7 3.57 2.6 1

2365 268 216 2.33 2.7 2

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

How was the surface prepared for the new paint?

Q44: Was hand scraping or hand sanding used?

1 . YES

2. NO

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio*

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 pg/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 87 18 9 3.04 2.36

2 8 1 0 2.25 2.22 -0.08 0.36 0.8300

8 1 0 1 5.07 3.76

2903 347 279 2.45 2.6 9

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

A-28
p. 93

Q45: Was powersanding, grinding, or sandblasting used ?

1 . YES

2. NO

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio*

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standar d

Category 7 pg/dL pg/dL Ng/dL Mean Deviation Estimate Error P-value

1 23 8 2 3.19 2.26

2 71 11 7 2.92 2.39 0.10 0.74 0.8918

8 2 0 1 2.22 5.5 6

. 2903 347 279 2.45 2.6 9

*Log-odds ratios were calculated assuming that missing values were ' No' response because people who didn't

do this R&R activity were not asked this question .

Q46: On which surfaces was power sanding, grinding, or sandblasting used?

1 . EXTERIOR WALLS

2 . TRIM/ EAVES

3 . PORCHES

4. DOORS / WINDOWS

5 . ROOF

ENTER ALL THAT APPLY SEPARATED BY SLASHES, d OR r, a FOR ALL

(delete)

A-29 ~
p. 94

Q47: Was an open flame torch used?

1 . YES

2 . NO

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category Ng/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 0 1 1 9.80 1 .22

2 94 18 8 2.91 2.35

8 2 0 1 2.22 5.56

2903 347 279 2.45 2.69

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

Q48: Were heat guns used?

1 . YES

2 . NO

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB Z 10 Geometric Standard Standar d

Category Ng/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 7 3 1 4.55 1.89

2 87 16 8 2.82 2.42 -0.40 1 .07 0.7104

8 2 0 1 2.22 5.5 6

2903 347 279 2.45 2.69

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

A-30
p. 95

Q49: Was washing, wet scraping, wet sanding, or water blasting used?

1 . YES

2. NO

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB a 10 Geometric Standard Standar d

Category /ug/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 21 9 3 3.56 2.48

2 73 10 6 2.86 2.24 -0.40 0.62 0.5191

8 2 0 1 2.22 5.5 6

2903 347 279 2.45 2.6 9

'Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

Q50: Were chemical paint removers used?

1 . YES

2. NO

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category pg/dL /jg/dL Ng/dL Mean Deviation Estimate Error P-value

1 10 2 2 3.39 3.02

2 83 17 7 3.04 2.21 -0.74 0.78 0.3434

8 3 0 1 1.20 7.1 0

2903 347 279 2.45 2.6 9

"Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

A-31

~'
p. 96

Q51 : Who did the work?

1 . HEAD OR SPOUSE

2 . OTHER PERSON IN HH

3 . RELATIVE/FRIEND NOT IN HH

4. OWNER, BUILDING SUPERINTENDENT, APT STAFF

5 . PAID PROFESSIONAL CONTRACTOR

ENTER ALL THAT APPLY SEPARATED BY SLASHES, d OR r, a FOR ALL

(FOR EACH ITEM, THE ANSWER WILL BE :

1 . YES

2. NO

8 . DON'T KNOW

9 . REFUSED)

1 .

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB a 10 Geometric Standard Standard

Category Ng/dL /rg/dL Ng/dL Mean Deviation Estimate Error P-value

1 68 17 8 3 .35 2.30

2 28 1 2 1 .49 3.20 -0.20 0.38 0.5891

8 0 1 0 7.00 1.00

2903 347 279 2.45 2.69

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

2.

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB ~ 10 Geometric Standard Standar d

Category pg/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 6 0 0 3.48 1.47

2 90 18 10 2.90 2.49

8 0 1 0 7.00 1.00

2903 347 279 2 .45 2.69

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

A-32 ~._~
p. 97

3 .

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category pg/dL pg/dL Ng/dL Mean Deviation Estimate Error P-value

1 11 0 1 0.38 5.67

2 85 18 9 3.15 2.36 0.06 1 .05 0.9554

8 0 1 0 7.00 1.00

2903 347 279 2.45 2.6 9

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

4.

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category pg/dL Ng/dL pg/dL Mean Deviation Estimate Error P-value

1 5 0 0 2.48 1.82

2 91 18 10 2.95 2.45 20.03 0.00

8 0 1 0 7.00 1 .00

2903 347 279 2.45 2.69

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't 1:L_ L L

do this R&R activity were not asked this question .

5 .

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category pg/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

1 22 1 1 1.70 2.90

2 74 17 9 3.20 2.36 0.76 1 .02 0.4609

8 0 1 0 7.00 1.00

2903 347 279 2.45 2.69

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

A-33

~7
p. 98

Q52: When was this job started and when was it completed? (If more than one job was done,

then enter the start date of the first job and the ending date of the last one .)

ENTER MONTH AND YEAR FOR EACH ON SEPARATE LINES d OR r

ENTER n FOR COMPLETION DATE IF WORK IS STILL IN PROGRESS

Q53: Did anyone in your household live in your home while the work was being done?

1 . YES

2 . NO

8 . DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB 2 10 Geometric Standard Standard Category Ng/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 86 19 10 3.22 2.34

2 10 0 0 2.76 1.05 -0.19 0.34 0.5683

2903 347 279 2.45 2.69

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

A-34

(Z-0
P. 99

CARPETS AND FLOORS

Q54: Were any carpets replaced or removed or painted floors refinished in the last 12 months?

1 . YES

2 . NO

8 . DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category Ng/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 517 91 65 2.94 2.54

2 2472 272 220 2.38 2.66 -0 .35 0.15 0.0206

8 10 3 0 3.49 1.79

Q55: Do you have any wall-to-wall carpeting in your home?

1 . YES

2 . NO

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category pg/dL Ng/dL pg%dL Mean Deviation Estimate Error P-value

1 499 79 61 2.74 2.67

2 144 23 9 2.99 2 .14 -0.67 0.37 0.0694

8 1 0 0 2.76 1.05

2355 264 215 2.41 2.66

A-35 ~

~
p. 100

Q56: Did you replace or remove a wall-to-wall or other large carpet in the last 12 months?

1 . YES

2. NO

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category Ng/dL /jg/dL pg/dL Mean Deviation Estimate Error P-value

1 432 61 50 2.59 2.74

2 209 40 20 3.14 2.26 -0.22 0.16 0.1868

8 3 1 0 2.51 2.1 3

2355 264 219 2.38 2.7 1

"Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

A-36

/~V
p. 101

READ IF FLOOR SURFACE OR COVERING DISTURBE D

Q57: Was the surface for this carpet or jlooring job prepared by methods such as sanding or

scraping off old paint or adhesive ?

1 . YES

2 . NO

8. DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7s PbB Geometri c

Response PbB <7 < 10 PbB 2 10 Geometric Standard Standar d

Category Ng/dL /ig/dL pg/dL Mean Deviation Estimate Error P-value

1 165 21 20 2.15 3.1 4

2 417 76 44 3.03 2.40 -0.24 0.25 0.3182

8 62 5 6 2.49 2.54

r- i 2355 264 219 2.38 2.7 1

*Log-odds ratios were calculated, assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

How was the surface prepared for the carpet or flooring?

Q58: Was hand scraping or hand sanding used?

1 . YES

2 . NO

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category pg/dL pg/dL /jg/dL Mean Deviation Estimate Error P-value

1 132 17 14 2.21 2.8 6

2 26 4 5 2.64 3.59 -0.10 0.29 0.7241

8 7 0 1 0.15 18. 4

F- 1 2834 345 269 2.49 2.6 5

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

A-37

/

l/
p. 102

Q59: Was power sanding, grinding, or sandblasting used ?

1 . YES

2 . NO

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB 2t 10 Geometric Standard Standard

Category pg/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

1 51 7 6 2.86 2.82

2 106 14 13 1.95 3.17 -0.20 0.44 0.6396

8 8 0 1 0.11 20. 2

2834 345 269 2.49 2.65

"Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

Q60: Was an open flame torch used?

1 . YES

2. NO

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category pg/dL Ng/dL pg/dL Mean Deviation Estimate Error P-value

1 1 0 0 2.76 1.05

2 157 21 18 2.22 3.04

8 7 0 2 1.00 6.84

2834 345 269 2.49 2.6 5

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question.

A-38

~a~-
p. 103

Q61 : Were heat guns used?

1 . YES

2 . NO

8 . DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category Ng/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 3 0 2 1.53 42. 0

2 153 21 16 2.34 2.77 -1 .94 0.91 0.0336

8 9 0 2 0.51 10. 6

2834 345 269 2.49 2.6 5

"Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

Q62: Was washing, wet scraping, wet sanding, or water blasting used?

1 . YES

2 . NO

8 . DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometri c

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category Ng/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 30 6 2 2.10 2.9 2

2 127 15 16 2.27 3.02 0.37 0.73 0.6163

8 8 0 2 0.64 9.86

2834 345 269 2.49 2.65

"Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

A-39

1®3
p. 104

Q63: Were chemical paint removers used ?

1 . YES

2 . NO

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB ~ 10 Geometric Standard Standar d

Category Ng/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 22 4 2 1.98 4.43

2 133 17 17 2.30 2.86 0.06 0.74 0.9370

8 10 0 1 0.84 5.6 2

2834 345 269 2.49 2.6 5

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question.

Q64: Who did the work?

1 . HEAD OR SPOUSE

2. OTHER PERSON IN HH

3 . RELATIVE/FRIEND NOT IN HH

4. OWNER, BUILDING SUPERINTENDENT, APT STAFF

5 . P~GD PROFESSIONAL CONTRACTO R

ENTER ALL THAT APPLY SEPARATED BY SLASHES, d OR r, a FOR ALL

(FOR EACH ITEM, THE ANWER WILL BE:

1 . YES

2. NO

8. DON'T KNOW

9. REFUSED)

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response Pb6 <7 < 10 PbB z 10 Geometric Standard Standar d

Category /rg/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 110 18 11 2.31 3.00

2 53 3 9 1.87 3.47 -0.04 0.32 0.9067

8 2 0 0 2.76 1.05

2834 345 269 2.49 2.6 5

* Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question.

A-40 /
p. 105

2 .

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category /ig/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 27 2 1 2.22 2.29

2 136 19 19 2.22 3.22 0.96 1.02 0.3455

8 2 0 0 2.76 1.05

2834 345 269 2.49 2.65

*Log-odds ratios were calculated assuming that missing values were ' No' response because people who didn't

do this R&R activity were not asked this question.

3.

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category Ng/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 18 2 3 1.83 3.65

2 145 19 17 2.21 3.08 -0.55 0.63 0.3788

8 2 0 0 2.76 1.05

2834 345 269 2.49 2.65

- 1

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn' t

do this R&R activity were not asked this question .

4.

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category Ng/dL /jg/dL pg/dL Mean Deviation Estimate Error P-value

1 9 2 3 4.17 2.58

2 154 19 17 2.04 3.17 -1 .25 0.67 0.0624

8 2 0 0 2.76 1.05

2834 345 269 2.49 2.65

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

A-41

/(/5
p. 106

5 .

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category pg/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 42 1 2 1.45 2.77

2 121 20 18 2.49 3.08 0.71 0.73 0.3265

8 2 0 0 2.76 1.05

F_- i 2834 345 269 2.49 2.6 5

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

Q65: When was this job started and when was it completed? (If more than one job was done,

then enter the start date of the first job and the ending date of the last one )

ENTER MONTH AND YEAR FOR EACH ON SEPARATE LINES d OR r

ENTER n FOR COMPLETION DATE IF WORK IS STILL IN PROGRESS

Q66: Did anyone in your household live in the home while the work was being done?

1 . YES

2. NO

8 . DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category pg/dL pg/dL Ng/dL Mean Deviation Estimate Error P-value

1 129 14 12 1.86 3.22

2 36 7 8 3.14 2.85 0.04 0.31 0.9048

2834 345 269 2 .49 2.65

"Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question .

A-42

/06
p. 107

Q71 : As a result of the work that was done in your home were dust and dirt spread to 1. Only

the work area 2 . The rooms next to the work area 3. Throughout the house or 4. No dirt

or dust was generated?

1 . ONLY IN THE WORK AREA

2. IN THE ROOMS NEXT TO THE WORK

3 . THROUGHOUT THE HOUSE ,

4. NO DIRT OR DUST GENERATED

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB x 10 Geometric Standard Standard

Category Ng/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

1 725 101 77 2.63 2.67

2 211 29 24 2.75 2.73 0.07 0.25 0.7809

3 266 43 26 2.89 2.39 -0.08 0.24 0.7270

4 706 91 60 2.35 2.74 -0.20 0.15 0.1712

8 70 7 12 3.07 2.6 1

1021 95 90 2.23 2.70

*Log-odds ratios were calculated assuming that missing values were 'No' response because people who didn't

do this R&R activity were not asked this question.

A-43

107
p. 108

TESTING FOR BLOOD LEAD

Q200: Now I'd like to ask you about your child's blood test for lead. Was your child tested

because you asked for it, or because your nurse or doctor told you that your child

needed the test?

1 . I ASKED FOR IT

2 . DR/NURSE/CLINIC RECOMMENDED IT

3 . WIC RECOMMENDED

4 . SCHOOL REQUIRED

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category Ng/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 976 132 83 2.72 2.48

2 1241 136 126 2.31 2.79 0.18 0.15 0.2302

3 385 44 53 2.51 2.83 0.48 0.19 0.0095

4 163 22 12 2.36 2.58 -0.14 0.32 0.6524

8 232 32 11 2.63 2.22

2 0 0 2.76 1.05

Q200a: If someone else recommended it, was he or she from either the WIC program or from a

health department ?

1 . YES

2. NO

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category pg/dL Ng/dL pg/dL Mean Deviation Estimate Error P-value

1 1438 160 145 2.45 2.6 7

2 405 50 44 2.15 2.93 0.07 0.18 0.6805

8 178 24 13 2.23 2.69

978 132 83 2.71 2.48

A-44

/0
p. 109

Q200b: Has the children has a subsequent blood test ?

1 . YES

2 . NO

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category pg/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

1 150 26 139 5.81 2.70

2 2761 327 138 2.43 2.37 -2 .92 0.15 0.0001

8 88 13 8 2.59 2.66

Q201 : How many blood lead tests has [01) had in the past 12 months?

1 . ONE

2. TWO

3 . THREE

4. FOUR OR MORE

8. DON'T KNOW

9. REFUSED

(delete this question)

Q201 a: In which month and year was the first blood test?

ENTER MONTH/YEAR, E.G. 12/96 d OR r

A-45

/0
p. 110

Q201 b: For this test did they take the blood from the finger, the arm or someplace else?

1 . FINGER (capillary)

2. ARM (venous)

3 . SOMEPLACE ELSE(specify :___)

4. FOOT

5 . TOE

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category Ng/dL Ng/dL ~ug/dL Mean Deviation Estimate Error P-value

1 2377 296 179 2.52 2.47

2 179 19 85 4.02 3.26 1.84 0.15 0.0001

3 6 0 0 3.65 1.30 -19.8 29E3 0.9995

4 42 5 1 2.36 2.11 -1 .15 1 .01 0.2565

5 82 3 6 2.09 2.47 -0.03 0.43 0.9467

8 313 42 14 2.34 2.36

0 1 0 7.00 1 .00

Q201 c: What was the lead level ?

ENTER NUMBER FROM 0 TO 100 d OR r

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standar d

Category ug/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

0-4 245 24 21 1 .98 2.88

5-9 93 9 14 2.53 3 .01 0.56 0.37 0.1238

10-19 3 0 1 1.20 7.10 1.36 1 .18 0.2485

unknown 2561 286 141 2.40 2.4 1

refused 9 4 1 3.61 2.45

88 43 107 7.41 2.21

A-46 ~~
p. 111

Q221 : What is (TESTED CHILD) 's birthdate?

ENTER MONTH, DAY AND YEAR E .G. 11/18/92 d OR r

(Analysis is based on the year of birth)

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category Ng/dL Ng/dL pg/dL Mean Deviation Estimate Error P-value

90 202 20 10 1 .97 2.70

91 408 41 23 2.02 2.66 0.13 0.39 0.7380

92 419 55 44 2.59 2.67 0.75 0.36 0.0371

93 396 47 46 2.63 2.59 0.85 0.36 0.0177

94 482 70 58 2.93 2.47 0.89 0.35 0.0118

95 954 118 90 2.52 2.65 0.64 0.34 0.0595

96 115 9 10 1.61 3.09 0.56 0.46 0.2229

23 6 4 3.82 2.32

A-47

/f/
p. 112

HOUSEHOLD INFORMATION

Q300: How manypersons live in your household. . . counting all adults and children and

including yourself ?

ENTER #, d OR r

(Q300 -Q300m are not in data set)

So that we can make the correct reference to everyone there, please tell me just the first name (or some other way to identify those in the household), RELATIONSHIP TO {0l}, sex, and age of all

persons who live in your household. Let's start with you. . . . .

Name Relationship Sex Age Delete

300d 300e 300f 300g 300h

Q300i: Correct number ofpeople in household.

ENTER NUMBER

Q3001: Did respondent supply correct number of people in household?

1 . Yes

2 . No

Q300m: I've listed you, and (READ NAMES) . Have I missed anyone who usually lives there

but is now away from home ?

1 . YES, NEED TO ADD SOMEONE TO ROSTER (PRESS 2 OR 3 TIMES AS

NECESSARY)

2. NO, TABLE IS CORRECT AS I S

3 . I NEED TO CORRECT OR CHANGE A CELL

4 . I NEED TO DELETE ONE PERSON FROM THE ROSTER

I would like to ask a few questions about {01}'s eating habits.

A-48

~~` zl~-
p. 113

Q302: Does your family usually sit down together for one or more meals per day ?

1 . YES

2. NO

8 . DON'T KNOW

9 . REFUSED

Number of

B l ood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category Ng/dL /.rg/dL pg/dL Mean Deviation Estimate Error P-value

1 2853 346 266 2.48 2.63

2 145 20 19 2.68 2.62 0.34 0.25 0.1773

8 1 0 0 2.76 1.05

Q303: How often does (01) usually sit at the dining or kitchen table for meals? Would you say

always, sometimes, seldom or never?

1 . ALWAYS

2. SOMETIMES

3 . SELDOM

4. NEVER

6 . TOO YOUNG

8 . DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category Ng/dL /!g/dL pg/dL Mean Deviation Estimate Error P-value

1 2184 255 187 2.40 2.62

2 643 80 73 2.64 2.68 0.28 0.15 0.0519

3 73 12 10 3.22 2.43 0.47 0.35 0.1740

4 44 15 6 3.76 2.04 0.47 0.44 0.2922

6 53 4 9 2.09 3.38

8 2 0 0 2.76 1.05

A-49 /,,3
p. 114

Q304: How often does {01} wash his/her hands before eating? Would you say always,

sometimes, seldom or never ?

1 . ALWAYS 6. TOO YOUNG

2. SOMETIMES 8. DON'T KNOW

3. SELDOM 9. REFUSED

4. NEVER

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category Ng/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 1225 151 110 2.47 2.6 6

2 1441 180 146 2.49 2.64 0.12 0.13 0.3608

3 200 28 14 2.69 2.43 -0.25 0.29 0.3967

4 73 4 7 2.57 2.40 0.07 0.41 0.8721

6 55 3 7 1.72 3.3 1

8 5 0 1 2.91 2.2 1

Q305: How often does (01) use a plate when eating? Would you say always, sometimes,

seldom or never?

1 . ALWAYS 6. TOO YOUNG

2. SOMETIMES 8. DON'T KNOW

3 . SELDOM 9. REFUSED

4. NEVER

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometri c

Response PbB <7 < 10 PbB z 10 Geometric Standard Standard

Category pg/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 2414 321 228 2.55 2.60

2 353 30 32 2.47 2.60 -0.04 0.20 0.8351

3 52 7 9 2.15 3.43 0.61 0.37 0.0994'

4 101 5 8 1.79 2.79 -0.18 0.37 0.6378

6 76 3 8 1.69 3.28

8 3 0 0 2.76 1.05

A-50

/iL/
p. 115

ADULT OCCUPATIONS

Now I would like to ask a series of questions about your occupation or the occupation of any

other adult who lives in the household.

Q306: First, in thepast 12 months has any adult held a job doing paint removal including

scraping and sanding ?

1 . YES

2. NO

8 . DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7jrg/dL Ng/dL jig/dL Mean Deviation Estimate Error P-value

1 222 44 25 3.16 2.3 1

2 2768 321 259 2.43 2.67 -0.19 0.22 0.4013

8 8 1 1 1.64 3.04

1 0 0 2.76 1.05

Q307: (In the past 12 months, has any adult held a job in) Home remodeling and repair?

1 . YES

2 . NO

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 Ng/dL Ng/dL /lg/dL Mean Deviation Estimate Error P-value

1 284 49 29 2.95 2.3 6

2 2709 317 255 2 .44 2.67 -0.08 0.21 0.6923

8 5 0 1 1.05 4.2 1

1 0 0 2.76 1.05

A-51 iic
p. 116

Q308: (In the past 12 months, has any adult held a job in) Plumbing ?

1 . YES

2. NO

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 pg/dL Ng/dL /jg/dL Mean Deviation Estimate Error P-value

1 117 22 14 2.97 2.46

2 2877 344 269 2.47 2.63 -0.25 0.29 0.3948

8 4 0 2 4.47 4.30

1 0 0 2.76 1.05

Q309: (In the past 12 months, has any adult held a job in) Building demolition?

1 . YES

2 . NO

8. DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standar d

Category 7~rg/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 104 22 16 3.30 2.30

2 2886 344 266 2.45 2.65 -0.51 0.28 0.0635

8 8 0 3 3.65 2.7 9

1 0 0 2.76 1.05

A-52

1/6
p. 117

Q310: (In the past 12 months, has any adult held a job in) Welding?

1 . YES

2. NO

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 pg/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

1 297 43 29 2.76 2.44

2 2691 323 256 2.47 2.66 -0.03 0.21 0.8990

8 10 0 0 2.76 1.05

1 0 0 2.76 1.05

Q311 : (In the past 12 months, has any adult held a job in) A battery manufacturing plant?

1 . YES

2 . NO

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB 2 10 Geometric Standard Standard

Category 7 pg/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 19 2 2 2.34 2.95

2 2975 363 283 2.49 2.63 -0 .10 0.75 0.8920

8 4 1 0 3.64 1.84

1 0 0 2.76 1.05

A-53

//7
p. 118

Q312: (In the past 12 months, has any adult held a job in) The salvage of batteries o r

radiators?

1 . YES

2. NO

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standar d

Category 7 Ng/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 34 4 10 3 .98 2.5 3

2 2960 360 275 2.47 2.63 -1 .15 0.37 0.0016

8 4 2 0 4.36 1.7 7

F_.

1 0 0 2.76 1.05

Q313 : (In the past 12 months, has any adult held a job in) Ship building or repair?

1 . YES

2 . NO

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 Ng/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 21 4 3 3.54 2.28

2 2977 361 281 2 .48 2.64 -0.41 0.62 0.5041

8 0 1 1 10.4 1 .1 5

1

1 0 0 2.76 1.05

Q314: (In the past 12 months, has any adult held a job in) Other lead-related industry work?

(delete)

A-54 ~ ~
p. 119

Q315: (In the past 12 months, has any adult held a job in) Smelter or foundry work?

1 . YES

2. NO

8 . DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 Ng/dL Ng/dL pg/dL Mean Deviation Estimate Error P-value

1 94 18 14 3.72 2.23

2 2888 345 270 2.44 2.66 -0 .47 0.29 0.1126

8 16 3 1 3.27 2.25

1 0 0 2.76 1.05

Q316: (In the past 12 months, has any adult held a job in) Oil refinery work?

1 . YES

2 . NO

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 Ng/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 9 1 0 3.72 1.5 1

2 2989 364 284 2.48 2.64

8 0 1 1 8.94 1.12

1 0T 0 2.76 1.0 5

A-55 // I
p. 120

Q317: (In the past 12 months, has any adult held a job in) Auto body work ?

1 . YES

2. NO

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 Ng/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 157 34 16 3.05 2.33

2 2835 332 269 2.46 2.66 -0 .07 0.27 0.7914

8 6 0 0 2.89 1.42

1 0 0 2.76 1.05

Q318: (In the past 12 months, has any adult held a job in) Glass work?

1 . YES

2. NO

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7/jg/dL pg/dL Pg/dL Mean Deviation Estimate Error P-value

1 53 11 5 2.97 2.5 2

2 2943 354 280 2.48 2.64 0.01 0.47 0.9857

8 2 1 0 2.88 2.62

1 0 0 2.76 1.05

A56~~
p. 121

Q319: (In the past 12 months, has any adult held a job in) A chemical plant ?

1 . YES

2 . NO

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 Ng/dL jug/dL ug/dL Mean Deviation Estimate Error P-value

1 43 4 2 3.35 1.84

2 2951 361 283 2.47 2.65 0.72 0.73 0.3189

8 4 1 0 3.67 1.59

1

1 0 0 2.76 1.05

Q320: (In the past 12 months, has any adult held a job in) Sandblasting?

1 . YES

2. NO

8 . DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 ug/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 97 21 6 2.94 2.4 1

2 2894 344 278 2.48 2.64 0.44 0.43 0.3007

8 7 1 1 1.06 6.22

1 0 0 2.76 1.05

A-57

~~ ~
p. 122

Q321 : (In the past 12 months, has any adult held a job in) Other lead related occupations?

1 . YES

2 . NO

8 . DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7/jg/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 65 12 13 3.21 2.77

2 2888 345 266 2.46 2.64 -0.78 0.31 0.0125

8 45 9 6 3.34 2.1 2

1

1 0 0 2.76 1.0 5

Q322: (Has any one in the household worked at another lead related occupation in the past 12

months?) What jobs were they ?

ENTER EACH ADULT OCCUPATION AND INDUSTRY ON SAME LINE, d

OR r,

Response was either `other' or 'missing')

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 Ng/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

0 5 3 1 4.80 1.8 9

1 11 2 3 3.74 2.18 0 .31 1 .27 0.8077

2 8 1 2 3.04 2.58 0.22 1 .35 0.8688

3 2 0 0 2.76 1.05 -23.8 23E4 0.9999

4 6 1 1 3.07 2.73 -0 .18 1 .54 0.9057

5 5 0 1 0.44 10.6 0.00 1 .55 1 .0000

6 3 0 1 4.30 2.21 0.51 1 .59 0.7483

7 11 3 3 4.05 2.56 0.31 1 .27 0.8077

8 4 0 0 3.32 1.35 -23.8 16E4 0.9999

9 5 1 1 0.35 69.5 -0.00 1 .55 1 .0000

998 1 0 0 6.00 1.00

2938 355 272 2.48 2.63

A-58

l~~
p. 123

HOBBIES

Now I would like to ask a series of questions about hobbies of anyone who lives in the household .

Q324: Within the past 12 months, has anyone in the household removed paint or varnish from

furniture?

1 . YES

2. NO

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 Ng/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 334 48 36 2.85 2.43

2 2664 318 248 2.44 2.66 -0.15 0.19 0.4347

8 1 0 1 4.96 3.35

Q325: (Within the past 12 months, has anyone in the household) Soldered pipes or repaired

plumbing?

1 . YES

2 . NO

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z: 10 Geometric Standard Standard

Category 7 Ng/dL pg/dL /ig/dL Mean Deviation Estimate Error P-value

1 465 66 54 2.76 2.57

2 2529 298 231 2.44 2.65 -0.24 0.16 0.1319

8 5 2 0 2.56 2.43

A-59

~r~
p. 124

Q326: (Within the past 12 months, has anyone in the household) Joined pieces of staine d

glass with solder?

1 . YES

2 . NO

8 . DON'T KNOW

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 Ng/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

1 12 3 2 4.70 1.67

2 2986 363 283 2.47 2.65 -0.56 0.77 0.4613

8 1 0 0 5.00 1.00

Q327: (Within the past 12 months, has anyone in the household) Painted pictures or jewelry

with artists paint?

1 . YES

2. NO

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 pg/dL pg/dL Ng/dL Mean Deviation Estimate Error P-value

1 214 29 22 2.52 2.66

2 2774 336 263 2.49 2.64 -0.08 0.23 0.7282

8 11 1 0 2.92 1.64

A-60

;24
p. 125

Q328: (Within the past 12 months, has anyone in the household) Glazed pottery or cerami c

objects?

1 . YES

2. NO

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 pg/dL Ng/dL pg/dL Mean Deviation Estimate Error P-value

1 94 8 7 2.06 2.84

2 2903 358 277 2.50 2.63 0.25 0.40 0.5321

8 2 0 1 2.04 7.1 5

Q329: (Within the past 12 months, has anyone in the household) Performed auto maintenance

or body repair near the house ?

(REFERS TO BODY WORK, BATTERY WORK OR RADIATOR REPAIR - DOES

NOT INCLUDE OIL CHANGES, LUBRICATION, ETC.)

1 . YES

2. NO

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB 2 10 Geometric Standard Standard

Category 7 Ng/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

1 655 90 71 2.79 2.56

2 2342 275 213 2.40 2.65 -0.18 0.14 0.2229

8 1 1 1 7.82 3.37

1 0 0 6.00 1.00

A-61

125
p. 126

Q330: (Within the past 12 months, has anyone in the household) Molded lead into bullets,

sinkers or other objects ?

1 . YES

2 . NO

8 . DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 Ng/dL Ng/dL /!g/dL Mean Deviation Estimate Error P-value

1 40 4 6 1.94 3.6 0

2 2956 362 279 2.50 2.62 -0.46 0.44 0.2949

8 3 0 0 2.76 1.05

Q331 : Has any one in the household worked at another lead related hobby in the past 12

months ?

1 . YES

2. NO

8 . DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 ug/dL pg/dL /rg/dL Mean Deviation Estimate Error P-value

1 45 9 7 3.52 2.59

2 2939 355 274 2.47 2.63 -0.51 0.41 0.2131

8 15 2 4 3.27 2.43

A-62

~ ~
p. 127

Q332: What hobbies were they?

ENTER ALL HOBBIES AND PERSON NUMBER'S ON SEPARATE LINES, d

OR r,

(The following analysis is based on the number of hobbies)

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB PbB z Geometri c

Response PbB < < 10 10 Geometric Standard Standard

Category 7 pg/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

0 6 0 0 2.89 1.42

1 6 1 1 3.17 2.36

2 7 2 2 4.41 3.97

3 15 3 4 4.22 2.32

4 6 1 0 3.02 1.72

5 1 1 0 4.38 1.67

6 2 1 0 5.33 1.50

98 2 0 0 4.27 1.45

2954 357 278 2.47 2.63

A-63

/Z 7
p. 128

BACKGROUND

Now we just have a few background questions to help us to interpret the results of this study .

Q333: How many people live in your household. . . counting all adults and children and

including yourself?

ENTER #, d OR r

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 Ng/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

<= 2 1 1 1 18 10 2.91 2.46

3 602 75 46 2.45 2.53 -0.16 0.36 0.6509

4 1046 119 89 2.30 2.66 -0.06 0.35 0.8696

5 704 64 65 2.28 2.81 0.02 0.35 0.9448

6 293 52 33 2.91 2.47 0.22 0.38 0.5545

> 7 241 38 42 3.25 2.54 0.66 0.37 0.0746

2 0 0 2.76 1.05

A-64

171
p. 129

Q333a: What was your marital status ?

1 . DIVORCED

2. WIDOWED

3 . SEPARATED

4. NEVER BEEN MARRIED

5 . MEMBER OF AN UNM

6. MARRIED

8 . DON'T KNOW/NOT SURE

9 . REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 pg/dL Ng/dL pg/dL Mean Deviation Estimate Error P-value

1 224 28 23 2.52 2.59

2 10 5 1 3.82 1.96 -0.03 1 .07 0.9803

3 102 13 10 2.39 2.83 -0.05 0.40 0.9073

4 311 45 31 2.70 2.68 -0.03 0.29 0.9182

5 110 13 18 2.87 2.63 0.47 0.34 0.1649

6 2235 261 206 2.41 2.68 -0.11 0.23 0.6399

8 2 0 0 2.76 1.05

5 1 0 1.77 2.41

A-65

1 2q
p. 130

Q333d: What was the highest grade or year in school that (you have /{:B) has) completed?

0 . 8TH GRADE OR LES S

1 . 9TH -11 TH GRADE

2 . H.S. GRADUATE OR HAS G.E .D.

3 . SOME TECHNICAL SCHOOL OR VOCATIONAL TRAINING

4 . TECHNICAL SCHOOL GRADUATE

5 . SOME COLLEGE OR ASSOCIATE DEGREE

6 . COLLEGE GRADUAT E

7. POST GRADUATE OR PROFESSIONAL DEGREE

9. DON'T KNOW / REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB ~ 10 Geometric Standard Standard

Category 7 pg/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

0 67 12 23 4.06 2.67

1 244 40 38 3.39 2.37 -0.79 0.30 0.0080

2 1188 157 118 2.55 2.65 -1 .24 0.26 0.0001

3 254 30 24 2.54 2.59 - 1 .29 0.32 0.0001

4 153 17 15 2.76 2.63 - 1 .25 0.36 0.0006

5 595 61 36 2.20 2 .54 -1 .74 0.30 0.0001

6 364 42 20 2.16 2.53 - 1 .83 0.33 0.0001

7 126 6 11 1.39 3.50 -1 .37 0.40 0.0006

8 1 0 2.59 1.8 1

A-66

J~ 30
p. 131

Q333p: What was the highest grade or year in school that (your partner/spouse have /{: B} has)

completed?

0. 8TH GRADE OR LESS

1 . 9TH - 11 TH GRADE

2 . H.S. GRADUATE OR HAS G.E.D.

3 . SOME TECHNICAL SCHOOL OR VOCATIONAL TRAINING

4. TECHNICAL SCHOOL GRADUATE

5 . SOME COLLEGE OR ASSOCIATE DEGREE

6. COLLEGE GRADUATE

7. POST GRADUATE OR PROFESSIONAL DEGREE

9. DON'T KNOW / REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 pg/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

0 76 11 19 3.34 2.69

1 200 24 30 3.18 2.58 -0.51 0.32 0.1134

2 995 134 85 2.62 2.52 - 1 .07 0.28 0.0001

3 155 17 11 2.30 2.63 -1 .26 0.40 0.0018

4 150 15 10 2.31 2.35 -1 .32 0.42 0.0015

5 340 34 34 2.13 2.85 -0.92 0.31 0.0034

6 299 32 20 1.90 2.96 - 1 .32 0.35 0.0001

7 119 7 10 1.39 3.69 - 1 .09 0.42 0.0090

665 92 70 2.62 2.6 7

A-67

131
p. 132

INCOME

Q335: Is your household income more or less than $30, 000 per year?

1 . MORE THAN 30,000

2. LESS THAN 30,000

8. DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 pg/dL /jg/dL Ng/dL Mean Deviation Estimate Error P-value

1 1299 139 83 2.12 2.67

2 1606 213 193 2.78 2.59 0.63 0.14 0.0001

8 65 11 8 2.54 2.68

29 3 1 2.54 2.1 8

Q335a: Thank you very much for your help with these questions. I have some information for

you on lead poisoning prevention. Would you like me to send it to you ?

1 . YES

2 . NO

8 . DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 pg/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

1 1537 188 150 2.58 2.59

2 1457 178 135 2.39 2.69 -0 .05 0.12 0.6758

8 2 0 0 4.15 1.23

3 0 0 2.76 1.05

A-68 ~~
p. 133

Q335b: The address we have for you is (0k) Is that correct ?

1 . YES

2 . NO

8 . DON'T KNOW

9. REFUSED

Number of

Blood-Lead

Concentration Log-Odds Ratio

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 Ng/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

1 162 17 18 2.37 2.80

2 29 3 2 3.53 1.87 -0.48 0.77 0.5368

2808 346 269 2.46 2.68

Q336: What is your correct address ?

ENTER COMPLETE ADDRESS INCLUDING ZIP CODE ON SEPARATE LINES

A-69

I,3 3.
p. 134

This page intentionally blank.

A-70

13
p. 135

APPENDIX B :

LOGISTIC REGRESSION BACKGROUND

B-, ' ~~
p. 136

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B-2

/36
p. 137

APPENDIX B : LOGISTIC REGRESSION BACKGROUN D

Logistic regression (McCullagh and Nelder, 1989) is a commonly used method for

analyzing the data from a retrospective case control study . In this study, children were selected

based on their observed blood-lead concentrations. Since the purpose of this study was to assess

the impact of renovation and remodeling activities on children's blood-lead concentrations, an

analysis methodology that respects the fact that observations were chosen based on the value of

the response variable must be used .

One inference mechanism useful for retrospective, binomial data is the odds ratio. An

odds ratio is a fraction with the odds for one group of children in the denominator and the odds

for a second group in the numerator . The odds for a group are the probability that a subject in

that group has some condition over the probability that a subject does not have the condition . In

this study, the odds of interest are the probability of an elevated blood-lead concentration divided

by the probability of a nonelevated blood-lead concentration . Groups are defined by responses to

particular questions. An odds ratio statistically greater than 1 indicates that the numerator group

of children is at higher risk as a result of lead exposure .

In a prospective study a group of children with a specified risk factor are first identified

and then blood-lead concentrations are measured . In a retrospective study, risk factors are

determined for a group of children whose blood-lead concentrations were previously measured .

The odds ratio for a retrospective study:

Pr(RR I Case) / Pr(No RR I Case)

s~' __ Pr(RR I Control) / Pr(No RR I Control)

is identical (in interpretation) to that for a prospective study :

Pr(Case I RR) / Pr(Control I RR)

~~0~~ Study Pr(Case I No RR) / Pr(Control ( No RR)

where

Pr(RR I Case) / Pr(No RR I Case)

~~~70~~ S~' Pr(RR I Control) / Pr(No RR I Control)

is identical (in interpretation) to that for a prospective study :

where

Pr(RRICase) - the conditional probability of renovation and remodeling

having been performed in a house with a child whose

blood-lead concentration exceeds 10 μg/dL,

B-3

157
p. 138

Pr(No RRI Case) = the conditional probability of no renovation and remodeling

having been performed in a house with a child whos e

blood-lead concentration exceeds 10 μg/dL,

Pr(RRI Control) = the conditional probability of renovation and remodeling

having been performed in a house with a child whose

blood-lead concentration does not exceed 10 μg/dL, and

Pr(no RRI Control) = the conditional probability of no renovation and remodeling

having been performed in a house with a child whose

blood-lead concentration does not exceed 10 μg/dL.

Cases = Residences containing children with a blood-lead

concentration exceeding 10 μg/dL.

The odds ratio is used to test whether the incidence of elevated blood-lead concentrations

in homes in which renovation and remodeling occurred is greater th an that in which renovation

and remodeling did not occur. For example, an odds ratio of 2 may be interpreted as the odds of

a child's blood-lead concentration exceeding 10 μg/dL increases twofold with the conduct of

renovation and remodeling.

The odds ratio is the natural form of inference based on logistic regression . Logistic

regression models the probability of an event in the following form

P(xl,x2,x3'

. . .,xp) = 1

1 +e -(Po+P,x,+P92 + . . .+adrv)

where x,, x2, . . ., xP are predictors of the event and p(x,, xz, . . ., xP) is the probability of the event

given the values of the predictor variables. Alternatively, the logistic regression model c an be

written as

Int 1P`x 2~3

'

. .~~ Pp+R1x1+R27C2+ . . .+R~1Cp (1)

P(

x

1,X2,X3,

•

,xp)

Therefore, the logistic regression model assumes that the log-tr ansformed odds ratio at one set of predictor variables is a linear function of the parameters PO , P,, P21 . . . I P .

Log odds differences are calculated to compare the odds at one set of predictor va riables to the odds at another set of predictor variables by differencing the appropri ate linear functions of the parameters,

Inyr = In p(xl' X2- -'-x,-' _ ln P(YI, Ya, Yp)

-P(

)

XI, x2, . .

., xp) 1- (Yl,Ya, . .

., Yp)

B-4

~ .~~
p. 139

Odds ratios, *, are calculated by exponentiating the log odds difference . To compare the odds

for two groups that are different only in one predictor va riable, for example, the log odds

difference is equal to the parameter associated with that predictor multiplied by the difference in

the predictor variable between the two groups. The odds ratio is calculated by exponentiating

that value.

B-5 I

3

r}
p. 140

This page intentionally blank.

B-6
p. 141

APPENDIX C :

TEST-WISE SIGNIFICANT RESULTS

c-i

I',!
p. 142

This page intentionally blank.

G2/~ A
p. 143

APPENDIX C : TEST-WISE SIGNIFICANT RESULTS

This appendix presents all the univariate logistic regressions for which the test-wise

significance level was less than 10 percent, but the result failed to qualify for significance with

the Holm Bonferroni correction. Results are sorted by magnitude of the odds ratios under the

restriction that odds ratios based on a single question remain together.

Table C-1 . Odds Ratio Estimates and 95 percent Confidence Inte rvals, Test-Wise

Significant Question Responses

All Children with Blood-Lead Concentrations <7pg/dL or 10 pg/dL

n = 288

Odds Ratio

95% Confidence

Question Higher Risk Grou Lower Risk Grou Estimate Interval

032 Open flame torch (outside) Yes No 7.029 [1 .139, 43.381

Q61 Heat gun (carpet & floor) Yes No 6.959 [1 .127, 42.9481

033 Heat gun (outside) Yes No 6.89 [2.915, 16.281 1

0201 b Blood drawn from finger, arm or Arm ( venous) Finger (capillary) 6.297 [8.499, 4.6651

someplace els e

Q333d Highest grade completed by 8th Grade or less Some College 5 .697 (3 .127, 10.381 1

respondent

Q333d Highest grade completed by 8th Grade or less Tech. Grad. 3.49 [1 .699, 7 .171 1

respondent

Q333d Highest grade completed by 8th Grade or less College Grad . 6.234 [3.222, 12 .061 1

respondent

Q333d Highest grade completed by 8th Grade or less Post Grad . 3.935 [1.768, 8.7581

respondent

Q333d Highest grade completed by 8th Grade or less H .S. Grad or GED 3.456 [2.054, 5.8121

respondent

Q333d Highest grade completed by 8th Grade or less Some Tech or 3.633 [1 .916, 6.891

respondent Vocational

Q333d Highest grade completed by 8th Grade or less 9th - 11th Grade 2.203 [1.209, 4.015]

respondent

Q35 Chemical paint remover ( outside) Yes No 3.743 [1.433, 9.7771

Q64_4 Owner, staff did work ( carpet & Yes No 3.49 [0.914, 13.331

floor)

Q23 In how many rooms 2 4 1 3.158 [1.507, 6.6191

Q312 Adult occupation in salvage of Yes No 3 .158 [1.507, 6.6191

batteries or radiator s

Q36_3 Relative not in household did Yes No 2 .746 [0.99, 7.6141

work (outside )

Q221 Date of birth for tested child 95 90 1.896 [3 .743, 0.961 1

C-3

143
p. 144

Table C-1 a . (Continued )

All Children with Blood-Lead Concentrations < 7/ig/dL or 210 pgldL

n = 2

dds Rati o

95% Confidence

Question Higher Risk GrouD Lower Risk Group Estimate Interval

0221 Date of birth for tested child 93 90 2.34 [4.807, 1 .139]

0221 Date of birth for tested child 94 90 2.435 [4.904, 1 .2091

Q221 Date of birth for tested child 92 90 2.117 [4.349, 1 .031

Q321 Adult occupation in other lead Yes No 2 .181 [1.174, 4.055]

,related occupation

Q31 Power sanding, grinding or Yes No 2.034 [0.97, 4.2631

sandblasting (outside)

Q24 Any work in kitchen Yes No 1 .974 [1 .271, 3.065]

Q55 Any wall to wall carpet in home Yes No 1 .954 [0.932, 4.096]

Q333 How many people live in 27 52 1 .935 [4.055, 0.923]

household

0335 Household Income It 30,000. gt 30,000. 1.878 [2.484, 1 .419]

Q19 Chemical paint remover (inside) Yes No 1 .84 [0.97, 3.49]

0305 How often does the tested child Seldom Always 1 .84 [3.857, 0.878]

use a plat e

034 Washing, wet scraping, wet Yes No 1 .786 [0.98, 3.254]

sanding or water blasting

(outside)

Q309 Adult occupation in building Yes No 1 .665 [0.951, 2.9151

demolitio n

Q28 Any outside painting Yes No 1.632 [1 .162, 2 .2931

Q200 Who asked for blood test Wisconsin I asked for it 1 .616 [2.363, 1 .105]

recommende d

025 Any work in bathroom Yes No 1.537 [0.99, 2 .387]

Q54 Carpets replaced or removed or Yes No 1 .419 [1.051, 1 .9161

painted floors refinished

0303 Does the tested child sit at the Sometimes Always 1 .323 [1.786, 0.981

Ijable

C-4

14 ~
p. 145

APPENDIX D :

UNIVARIATE REGRESSION OF

CONSTRUCTED R&R VARIABLES

D-1 /q5-
p. 146

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D-2

~~ ~
p. 147

Univariate Regression of Constructed R&R Variables

Any R&R Work

Was any renovation and remodeling work done in the last 12 months, including interior painting

or exterior painting or were windows replaced, walls moved, carpets replaced, or, floors

resurfaced?

1 . YES

2. NO

Number of

Blood-Lead

Concentration Log-Odds Difference*

7!g PbB < Geometric

Response PbB <7 10 PbB z 10 Geometric Standard Standard

Catego ry pg/dL pg/dL Ng/dL Mean Deviation Estimate Error P-value

1 1836 251 187 2.61 2.6 3

2 1151 113 92 2.28 2.61 -0.48 0.16 0.0024

12 2 6 4.27 2.9 9

Inside Painting

During the last 12 months, was there any painting or were any surfaces prepared for paint inside

the home?

l . YES

2. NO

Number of

Blood-Lead

Concentration Log-Odds Difference

7 :g PbB < Geometri c

Response PbB <7 10 PbB z 10 Geometric Standard Standard

Catego ry pg/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

1 1371 181 128 2.54 2.63

2 1620 185 155 2.45 2.63 - 0 .14 0.14 0.3222

8 0 2 0.88 6.62

D-3 ~A
p. 148

Other Repairs (Window)

Were any windows repaired or new windows put in?

1 . YES

2 . NO

Number of

Blood-Lead

Concentration Log-Odds Difference

7 s PbB < Geometric

Response PbB <7 10 PbB z 10 Geometric Standard Standar d

Category Ng/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

1 592 93 68 3.00 2.46

2 2402 271 214 2.35 2.68 -0.25 0.17 0.1283

. 5 2 3 4.64 2.78

Inside or Outside Painting

During the last 12 months, was there any painting or were any surfaces prepared for paint inside

or outside the home ?

1 . YES

2. NO

Number of

Blood-Lead

Concentration Log-Odds Difference

7 s PbB < Geometric

Response PbB <7 10 PbB z 10 Geometric Standard Standar d

Category pg/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

1 1535 203 155 2.55 2.65

2 1451 161 125 2.43 2.58 -0.31 0.14 0.0304

13 2 5 2.51 4.22

D-4

I L18
p. 149

Prepared Surface

Were any surfaces prepared for interior painting, exterior painting, window installation/wall

repair or carpet replacement, or floor resurfacing by methods such as sanding, scraping, or use

of chemicals other than prime painting ?

1 . YES

2. NO

Number of

Blood-Lead

Concentration Log-Odds Difference

7 s PbB < Geometri c

Response PbB <7 10 PbB z 10 Geometric Standard Standard

Catego ry pg/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

1 527 84 66 2.87 2.6 0

2 2348 266 204 2.38 2.65 -0 .51 0.16 0.0019

124 16 15 2.98 2.51

Prepared Surface for Inside Paintin g

Were any surfaces prepared for interior painting by methods such as sanding, scraping, or use

of chemicals other than prime painting?

1 . YES

2 . NO

Number of

Blood-Lead

Concentration Log-Odds Difference

7 s PbB < Geometric

Response PbB <7 10 PbB 2 10 Geometric Standard Standar d

Catego ry pg/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

1 283 48 34 3.22 2.40

2 2651 314 244 2.41 2.66 -0.39 0.21 0.0627

65 4 7 2.32 2.90

D-5 /q9
p. 150

Hand Sanding or Scrapin g

Was hand scraping or hand sanding used to prepare surfaces for inside painting, outside

painting, window installation or wall repair, or when carpets were replaced or, floors

resurfaced?

1 .YES

2. NO

Number of

Blood-Lead

Concentration Log-Odds Difference

7 s PbB < Geometric

Response PbB <7 10 PbB ~ 10 Geometric Standard Standar d

Category pg/dL pg/dL pg/dL Mean Deviation Estimate Error P -value

1 481 76 54 2.84 2.50

2 2503 289 227 2.42 2.65 -0.32 0.17 0.0671

15 1 4 2.41 4.21

Power Sanding, Grinding, Sandblastin g

Was power sanding, grinding, or sandblasting used to prepare the surface for interior painting,

exterior painting, window installation/wall repair, carpet replacement, or floor resurfacing ?

1 . YES

2 . NO

Number of

Blood-Lead

Concentration Log-Odds Difference

7 s PbB < Geometri c

Response PbB <7 10 PbB z 10 Geometric Standard Standard

Category pg/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

1 146 29 22 3.33 2.4 7

2 2829 334 260 2.44 2.64 -0 .68 0.25 0.0063

24 3 3 2.59 2.8 5

D-6

~ ~O
p. 151

Open Flame Torc h

Was an openflame torch used to prepare surfaces for insidepainting, outside painting, window

installation or wall repair, or for carpet replacement or floor resurfacing?

1 . YES

2. NO

Number of

Blood-Lead

Concentration Log-Odds Difference

7 s PbB < Geometric

Response PbB <7 10 PbB z 10 Geometric Standard Standard

Catego ry pg/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

1 6 0 2 3.04 2.7 8

2 2978 363 278 2.48 2.63 -1.54 0.82 0.0604

15 3 5 3.62 2.7 5

Heat Guns

Were heat guns used to prepare surface for inside painting, outside painting, window installation

or wall repair, or for carpet replacement or, floor resurfacing?

1 . YES

2. NO

Number of

Blood-Lead

Concentration Log-Odds Difference

7 s PbB < Geometri c

Response PbB <7 10 PbB z 10 Geometric Standard Standar d

Category pg/dL Ng/dL pg/dL Mean Deviation Estimate Error P-value

1 33 5 13 4.38 2.56

2 2947 358 266 2.47 2.62 -1 .58 0.36 0.0001

19 3 6 3.44 3.1 0

D-7
p. 152

Washing, Wetscraping, Waterblasting

Was washing, wet scraping, wet sanding, or water blasting used to prepare surfaces for inside

painting, outside painting, window installation or wall repair, or for carpet replacement or floor

resurfacing?

1 . YES

2. NO

Number of

Blood-Lead

Concentration Log-Odds Difference*

7 .5 PbB < Geometri c

Response PbB <7 10 PbB z 10 Geometric Standard Standard

Catego ry pg/dL Ng/dL pg/dL Mean Deviation Estimate Error P-value

1 144 30 22 3.23 2.44 0.00 0.0 0

2 2824 333 257 2.45 2.64 -0.53 0.27 0.0465

31 3 6 2.43 3.2 6

Chemical Paint Remover s

Were chemical paint removers used to prepare for inside painting or for outside painting, when

windows or walls were replaced/moved, when carpets were replaced, or whenfloors were

resurfaced?

1 . YES

2. NO

Number of

Blood-Lead

Concentration Log-Odds Difference

7 s PbB < Geometric

Response PbB <7 10 PbB z 10 Geometric Standard Standard

Catego ry pg/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

1 73, 12 12 3.49 2.62

2 2904 352 266 2.47 2.61 -0.78 0.33 0.0190

22 2 7 2.52 4.1 8

D-8

~ ~~
p. 153

Who did the work for interior painting, exterior painting, window work, or carpet or floor work?

1 . YES

2 . NO

Head of Household or Spouse

Number of

Blood-Lead

Concentration Log-Odds Difference

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 pg/dL pg/dL Ng/dL Mean Deviation Estimate Error P-value

1 394 66 41 2.96 2.41

2 2605 300 244 2.41 2.68 -0.23 0.19 0.2329

Other (than head) Person in Household

Number of

Blood-Lead

Concentration Log-Odds Difference

7 :5 PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standard

Category 7 pg/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

1 64 6 3 2.21 2.1 8

2 2935 360 282 2.48 2.64 -0.45 0.59 0.4483

Friend or Relative not in Household

Number of

Blood-Lead

Concentration Log-Odds Difference

7 s PbB Geometric

Response PbB < <10 PbB z 10 Geometric Standard Standard

Category 7 pg/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

1 54 10 13 3.39 2.5 2

2 2945 356 272 2.47 2.63 -0.59 0.41 0.1494

D-9

,~~
p. 154

Who did the work for interiorpainting, exterior painting, window work, or carpet or floor work?

(Continued)

Owner or Apartment Staff

Number of

Blood-Lead

Concentration Log-Odds Difference

7 s PbB Geometric

Response PbB < < 10 PbB z 10 Geometric Standard Standar d

Catego ry 7 pg/dL Ng/dL Ng/dL Mean Deviation Estimate Error P-value

1 64 11 12 2.78 3.1 1

2 2935 355 273 2.49 2.62 -0.79 0.35 0.0237

Professional

Number of

Blood-Lead

Concentration Log-Odds Difference

7 s PbB Geometri c

Response PbB < < 10 PbB z 10 Geometric Standard Standar d

Catego ry 7 pg/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

1 81 6 10 1.94 3.35

2 2918 360 275 2.50 2.62 -0.43 0.36 0.2258

D-10
p. 155

Live in Home While R&R was Don e

Did anyone live in your household while the work (inside painting, outside painting, window

work or floor work) was being done?

1 . YES

2. NO

Number of

Blood-Lead

Concentration Log-Odds Difference

7 s PbB < Geometri c

Response PbB <7 10 PbB i 10 Geometric Standard Standar d

Category pg/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

1 457 71 55 2.87 2.5 6

2 2542 295 230 2.42 2.65 -0.42 0.17 0.0151

Number of Rooms

In how many rooms in your home was this work done ?

ENTER NUMBER OF ROOMS d OR r OR 0 FOR NONE

Number of

Blood-Lead

Concentration Log-Odds Difference *

7 s PbB < Geometric

Response PbB <7 10 PbB z 10 Geometric Standard Standard

Category Ng/dL pg/dL pg/dL Mean Deviation Estimate Error P-value

0 2720 322 251 2.41 2.6 6

1 95 13 6 2.85 2.25 0.13 0.05 0.0089

2 63 10 7 2.99 2.4 7

3 34 8 3 3.71 2.32

z4 87 13 18 3.56 2.4 9

* Number of Rooms was entered as a continuous variable. Hence the log-odds difference compares n+l to n rooms. (See

Appendix B for details.)

D-11

/15S
p. 156

R&R Work in Kitchen

Was any of this (indoor painting and surface preparation) work done in the kitchen?

1 . YES

2 . NO

Number of

Blood-Lead

Concentration Log-Odds Difference*

7s PbB < Geometric

Response PbB <7 10 PbB z 10 Geometric Standard Standard

Category pg/dL pg/dL Ng/dL Mean Deviation Estimate Error P-value

1 117 27 20 3.18 2.6 9

2 2881 339 265 2.46 2.63 -0.66 0.28 0.0164

1 0 0 5.00 1.0 0

D-12
p. 157

50272-10 1

REPORT DOCUMENTATION 1 . REPORT NO . 2 . 3. Recipient's Accession No .

PAGE EPA-747-R-99-002

4. Title and Subtitle 5. Report Date

"Lead Exposure Associated with Renovation and Remodeling Activities : March 1999

Phase III, Wisconsin Childhood Blood-Lead Study"

6.

7 . Author(s) 8. Performing Organization Rept. No.

Nancy McMillan, Ron Menton, Kensuke Shirakawa, Abi Katz-Stein, Ben Pierce ,

and Ying-Liang Chou

9. Performing Organization Name and Address 10. Project/Task/Work Unit No.

G003470-05

Battelle Memorial Institut e

505 King Avenue 11. Contract(C) or Grant(G) No.

Columbus, Ohio 43201-2693 (C) 68-D5-000 8

12 . Sponsoring Organization Name and Address 13 . Type of Report & Period Covered

Final Report

U .S . Environmental Protection Agenc y

Office of Pollution Prevention and Toxics (7401) 14

401 M Street, S .W. Washington, D.C. 20460

15. Supplementary Notes

16. Abstract (Limit 200 words )

In 1992, the United States Congress enacted the Residential Lead-Based Paint Hazard Reduction Act, which required

(Section 402(c)) the U .S. Environmental Protection Agency to conduct a study of lead exposure associated with

renovation and remodeling activities ( R&R Study) . This report documents Phase II of that study . Phase III is a

retrospective study of the association between elevated blood lead (EBL) concentrations ( z 10 pg/dL) in children and the

incidence of R&R activities in their residences .

A subset of children were selected for participation from the Wisconsin Bureau of Public Health's blood lead registry .

Information on R&R activities in participating children's residences was obtained by telephone interview . The study

included 3,654 children . Logistic regression was used to determine if incidence of general or specific R&R activities in

residences was associated with increased risk of an EBL .

Based on statistical analysis, children residing in residences in which some R&R activity was conducted were estimated

to have odds of an EBL 1 .3 times greater than children residing in residences where no R&R was conducted . When paint

removal using a heat gun was performed . the odds of an EBL was 4 .6 times greater than if the work was not performed.

Other significant associations were found .

17. Document Analysi s

a . Descriptors : Blood-lead concentration, childhood health risks, lead-based paint, lead hazard, renovation and remodeling,

elevated blood-lead concentratio n

b . Identifiers/Open-Ended Terms : Section 402, Renovation and Remodeling Study

c. COSATI Field/Grou p

18. Availability Statement 19. Security Class (This Report) 21 . No. of Pages

Unclassified 156

Release Unlimited

20. Security Class (This Page) 22. Price

Unclassifie d

(See ANSI-239 .18) OPTIONAL FORM 272 (4-77)

~ (Formerly NTIS-35)

Depa rtment of Commerce