EPA 747-R-96-005
May 1997
LEAD EXPOSURE ASSOCIATED WITH
RENOVATION AND REMODELING ACTIVITIES:
SUMMARY REPORT
Prepared By
Battelle
505 King Avenue
Columbus, OH 43201
for
Technical Programs Branch
Chemical Management Division
Office of Pollution Prevention and Toxics
Office of Prevention, Pesticides, and Toxic Substances
U.S. Environmental Protection Agency
Washington, DC 20460
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DISCLAIMER
Mention of trade names, products, or services does not
convey, and should not be interpreted as conveying official EPA
approval, endorsement, or recommendations.
This report is copied on recycled paper.
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Contributing Organizations
This study was funded and managed by the U.S. Environmental Protection Agency. The
study was conducted collaboratively by two organizations under contract to the Environmental
Protection Agency, Battelle, and Midwest Research Institute. Each organization's responsibilities
are listed below.
Battelle
Battelle was responsible for designing the study, recruiting participants, collecting worker
questionnaire data and blood samples, creating and maintaining data bases, conducting statistical
analysis, and producing the final report.
Midwest Research Institute (MRI)
MRI was responsible for field data collection of environmental samples, chemical analysis
of environmental samples, and reporting of chemical analysis results.
U.S. Environmental Protection Agency
The Environmental Protection Agency was responsible for oversight in developing the
study plan, managing and coordinating the study, and reviewing and editing this report. EPA
Project Managers included Dan Reinhart, Darlene Watford, Susan Dillman, and Betsy Dutrow.
Cindy Stroup was the Branch Chief of the Technical Programs Branch under whose direction the
study was conducted.
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Acknowledgments
United Brotherhood of Carpenters
The United Brotherhood of Carpenters and Joiners of America (UBC) provided a list of
current members that was used to develop the sampling frame for union carpenters for the
Worker Characterization and Blood-Lead Study (WCBS). In addition, UBC reviewed the WCBS
questionnaire, assisted in pretesting the questionnaire, provided assistance in recruiting their
membership, and consulted in the design of the WCBS study. Special thanks go to John Repko,
Sigurd Lucassen, Edward Coryell, and Terry Nelson.
IV
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TABLE OF CONTENTS
Page
EXECUTIVE SUMMARY vii
1.0 INTRODUCTION 1
1.1 Scope and Objectives 2
1.2 Peer Review 3
2.0 CONCLUSIONS 6
3.0 DESIGN OF THE STUDY 9
3.1 Data Collection 11
3.2 Environmental Study Design 12
3.2.1 Objectives 12
3.2.2 Sampling 13
3.3 Blood-Lead Study Design 14
3.3.1 Objectives 14
3.3.2 Survey Design 14
3.3.3 Data Collected 15
3.4 Data Gaps and Limitations 16
4.0 RESULTS: EXPOSURE RELATED TO SPECIFIC R&R ACTIVITIES 18
4.1 Worker Exposure 18
4.1.1 Summary Measures of Worker Exposure 18
4.1.2 Relationship Between Blood-Lead Concentrations and Target Activities . 21
4.1.2.1 Construction of Statistical Models 21
4.1.2.2 Modeling Results 21
4.2 Occupant Exposure 22
5.0 RESULTS: EXPOSURE ASSOCIATED WITH SPECIFIC R&R 26
5.1 Summary of Worker Profile Information in the Blood-Lead Study 27
5.2 Worker Exposure 29
5.3 Occupant Exposure 32
6.0 REFERENCES 34
LIST OF TABLES
Table 1. Summary Measures of Worker Exposure to Airborne Lead 19
Table 2. Summary Statistics Relating Worker Blood-Lead Concentration to the
Frequency of Conducting Target R&R Activities 22
Table 3. Summary Measures of Potential Occupant Lead Exposures that Can Result
from Conducting Target and Generic R&R Activities 23
Table 4. The Effect of Cleanup on Reducing Lead Loadings on New Linoleum Floors
After Conduct of Two R&R Activities 25
Table 5. The Number of Workers Surveyed Within Each Worker Group in the
Blood-Lead Study 27
Table 6. Average Number of Days that Included Specific Activities for R&R Workers in
the Blood-Lead Study 28
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Table 7.
Table 8.
TABLE OF CONTENTS
(Continued)
Information for an Assessment of Worker Exposures Associated with Different
R&R Worker Groups
Information for an Assessment of Potential Occupant Exposures Associated
with Different R&R Worker Groups
Page
. 31
. 32
LIST OF FIGURES
Figure 1. Overall Design Structure of the Renovation and Remodeling Study 10
Figure 2. Hours of Activity That Would Result in an Estimated Geometric Mean 8-Hour
TWA of 50 fjg/m3 20
Figure 3. Estimated Distribution of Dust Lead in a 6' x 1' Region Extending from the
Activity Area for Various Activities 24
Figure 4. Exposure Assessment Strategies for R&R Workers and Building Occupants,
Along with Sources of Information in the R&R Study 26
Figure 5. Trends in Work Practices as Reported by Workers in the Blood-Lead Study 29
Figure 6. Histogram of Blood-Lead Concentration (Semi-logarithmic Scale) for Workers
in the Blood-Lead Study 30
Figure 7. Geometric Mean of Blood-Lead Concentration (Adjusted for Potential Confounding
Factors) and Associated 95% Confidence Intervals for Each Worker Group 31
VI
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EXECUTIVE SUMMARY
The Residential Lead-Based Paint Hazard Reduction Act (Section 402; Title X) required
the U.S. Environmental Protection Agency (EPA) to conduct a study of lead exposure associated
with renovation and remodeling (R&R) activities (the R&R study). This study, conducted from
1993 to 1995, gathered information to be used to help determine which groups of people
conducting R&R activities require training, certification, or educational materials. The study was
designed to satisfy two objectives:
1. Determine the extent to which persons engaged in various types of R&R activities
are exposed to lead.
2. 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.
The R&R study was conducted in several steps. The first step was an extensive literature
review and information gathering effort directed at accumulating all currently available
information on lead exposure related to R&R activities. The second step, EPA's first data
collection effort on the study, focused on measuring environmental lead produced by the conduct
of various R&R activities. This step, known as the Environmental Field Sampling Study,
collected 90 personal air samples and 556 settled dust samples to assess potential exposure to
R&R workers and building occupants resulting from selected R&R activities. In the third step,
known as the Worker Characterization and Blood-Lead Study, blood-lead measurements and
questionnaire information were collected from 585 R&R workers (a different set of workers from
those participating in the Environmental Field Sampling Study) to (1) characterize blood-lead
concentrations in specific worker groups, (2) determine if specific worker groups or specific R&R
activities are associated with increases in blood-lead concentrations, and (3) provide information
to develop worker activity profiles. An additional step in the R&R study, currently in the design
stages, will be a retrospective study to evaluate the impact of the conduct of R&R activities on
elevated blood-lead concentrations in children. This study, known as the Wisconsin Children's
Study and conducted jointly with the University of Wisconsin and the State of Wisconsin Public
Health Department, will compare the incidence of R&R activities in dwelling units containing a
child with elevated blood-lead concentration to that in dwelling units not containing children with
elevated blood-lead concentrations.
For many R&R activities conducted in the Environmental Field Sampling Study, airborne
lead levels taken within workers' breathing zones, measured in micrograms lead per cubic meter
(|ig/m3) of air, were often high when compared to the OSHA Permissible Exposure Limit (PEL)
of 50 |ig/m3. These levels, representing an average exposure for a worker over the duration of
performing R&R activity, averaged greater than 100 |ig/m3 for paint removal, interior demolition,
and sawing activities, and greater than 49 |ig/m3 for interior surface preparation and central
heating system maintenance/ repair. However, only one out of 581 workers whose blood-lead
VII
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concentrations were measured in the Worker Characterization and Blood-Lead Study had a
blood-lead concentration greater than 40 micrograms per deciliter (jig/dL). In fact, blood-lead
concentration exceeded 25 |ig/dL in only 7 of the 581 workers (1.2%) and exceeded 10 |ig/dL in
only 50 of the 581 workers (8.8%). Thus, study results show little evidence of elevated blood-
lead concentrations in workers (i.e., concentrations greater than 40 |ig/dL, which is the current
level set by the Occupational Safety and Health Administration (OSHA) at which full medical
surveillance of a worker is required), despite the potential for high airborne lead levels within
workers' breathing zones that can result from performing R&R activities.
Assessing occupant exposure is more difficult compared to worker exposure. In this
study, occupant exposure was characterized by measuring lead levels in environmental dust. With
the exception of carpet removal and drilling into plaster, all R&R activities deposited significant
amounts of lead onto the floors, ranging from 328 micrograms per square feet (|ig/ft2) for sawing
lead-based plaster to 42,900 |ig/ft2 for paint removal. These results indicate that there is a
potential for significant amounts of lead to be disturbed by R&R activities, well over the current
EPA guidance of 100 |ig/ft2 for floors. Occupants could be exposed to this lead if appropriate
containment and cleanup practices are not employed. However, the extent to which this potential
exposure translates into an actual internal dose for occupants, as well as any health effects, is
unknown. The impact of R&R activities on children's blood-lead concentration will be
investigated further in the Wisconsin Children's study.
In general, R&R activities that have the greatest potential for pronounced disturbance of
lead-based paint have the highest potential for generating lead exposure. Paint removal and
demolition activities resulted in the greatest exposure, while carpet removal was associated with
the least exposure. This finding was consistent for both environmental and blood-lead
measurements.
VIM
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1.0 INTRODUCTION
Lead poisoning has long been recognized as one of this country's most important
environmental health problems. With the phase-out of lead in gasoline in the United States that
occurred from the late 1970s through the 1980s, lead-based paint is now considered the primary
source of lead exposure, particularly for children and construction workers. Disturbing intact
lead-based paint surfaces during R&R activities may result in significant lead exposure for both
workers and building occupants. Extensive R&R is often performed in older homes or public
buildings which have a high probability of containing lead-based paint.
On October 29, 1992, the United States Congress enacted the Residential Lead-Based
Paint Hazard Reduction Act (Title X of HR 5334). This includes Title IV of the Toxic
Substances Control Act that requires the U.S. Environmental Protection Agency (EPA)
Administrator to conduct a study of lead exposure associated with R&R activities. In particular,
paragraph (2) of Section 402 (c) states:
The Administrator shall conduct a study of the extent to which per sons 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 results of the above study, hereafter referred to as the Renovation and Remodeling
(R&R) study, are documented in three reports:
"Lead Exposure Associated With Renovation and Remodeling Activities: Summary
Report"
"Lead Exposure Associated With Renovation and Remodeling Activities:
Environmental Field Sampling Study," a technical report on environmental
measurements of lead associated with renovation and remodeling. (This report also
includes the results of the literature review and a summary of data collected from
other extant sources.)
"Lead Exposure Associated With Renovation and Remodeling Activities: Worker
Characterization and Blood-Lead Study," a technical report on blood-lead levels and
work practices of R&R workers.
This report, the R&R Summary Report, presents overall results and conclusions of the
effort undertaken by EPA. Technical details concerning methodology and derivation of results
can be found in technical reports for the Environmental Field Sampling Study, hereafter referred
to as the Environmental Study, and the Worker Characterization and Blood-Lead Study, hereafter
referred to as the Blood-Lead Study.
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1.1 SCOPE AND OBJECTIVES
The scope of the study mandated by the Title X legislation called for an assessment of lead
exposure for different categories of:
Individuals (specifically R&R workers, building occupants, and other exposed
individuals)
Environments (specifically private housing constructed before 1978, public buildings
constructed before 1978, and commercial buildings)
R&R activities.
Public housing constructed before 1978, known as target housing., represented one
environment category in which lead exposure was to be assessed, while public or commercial
buildings were placed into one of two additional categories, according to whether or not children
regularly inhabited the buildings.
After consulting with other government agencies, lead poisoning prevention experts,
industry representatives, labor unions, and other concerned groups, the EPA identified eleven
categories of R&R activities with potential for lead exposure that could be addressed by this
study. These eleven categories of R&R activities, subsequently called target activities, were:
1. Paint removal
2. Surface preparation
3. Removal of large structures
4. Window replacement
5. Enclosure of exterior painted surfaces (i.e., siding)
6. Carpet or other floor covering removal
7. Wallpaper removal
8. HVAC (central heating system) repair or replacement including duct work
9. Repairs or additions resulting in isolated small surface disruptions
10. Exterior soil disruption
11. Major renovation projects involving multiple target activities.
The information collected under the scope of the R&R study is to be used to help
determine which groups of people require training, certification, or educational materials because
of the potential lead exposure associated with activities they perform. The study was designed to
satisfy two objectives:
1. Determine the extent to which persons engaged in various types of R&R activities in
target housing, public buildings constructed before 1978, and commercial buildings
are exposed to lead.
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2. 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
occupants or other exposed individuals.
The R&R study addressed these objectives by collecting information that could be used to assess
lead exposure associated both with specific R&R activities and with different R&R worker
groups. Two data collection efforts were conducted in this study to collect the following
information:
1. Environmental measurements of lead, primarily personal air and settled dust
samples, to measure potential lead exposure to workers and occupants.
Environmental measurements of lead were collected during the specific R&R
activities in Baltimore, Maryland; Columbus, Ohio; Oakland, California; St. Louis,
Missouri; and Denver, Colorado.
2. Blood-lead measurements and questionnaire information from R&R workers to
assess worker exposure and help characterize R&R work practices. Blood-lead
measurements were collected from 581 R&R workers in Philadelphia, Pennsylvania,
and St. Louis, Missouri.
The environmental sampling process was independent of the worker blood and
questionnaire data collection. No R&R workers participating in the blood and questionnaire data
collection were involved in R&R activities associated with environmental sampling.
1.2 PEER REVIEW
The Summary Report, as well as both the Environmental Field Sampling Study (EFSS)
report and the Worker Characterization and Blood-Lead Study (WCBS) report, were reviewed
independently by members of a peer review panel. Comments which are important for
interpreting the study results or which resulted in important modifications to the report are
discussed below. All peer reviewers recommended publishing all reports with minor revisions.
A primary concern for a number of reviewers was the limited sample sizes, especially for
the EFSS study. Both the Summary Report and the EFSS report include a separate section which
discusses data gaps and data limitations. In addition, the sample size consideration has been
highlighted through characterization of the EFSS independent monitoring jobs as case studies and
through judicious use of language such as "potential for disturbing significant amounts of lead
during R&R activities" that do not overstate conclusions that can be drawn from this data. Sample
sizes are discussed and documented throughout all reports.
Related to the sample size issue, was concern over the number of statistical analyses
conducted and the exploratory nature of some analyses. Additional cautionary language was
added to the reports to warn of exploratory analyses, the effect of multiple statistical comparisons,
and the limitation of small sample size on the ability to detect statistical significance.
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Another concern expressed by reviewers was the relevance of abatement data to an
exposure assessment for R&R workers, and similarly the effect of using trained abatement
workers for some of the work conducted in the EFSS. Several sections of the EFSS report
address these concerns directly. Section 2.1, Relevance of Information on Abatement, and
Section 2.2, Characterization of Renovation and Remodeling, discuss the differences between
abatement work and renovation and remodeling. Section 5.0, Overview of Recruitment,
addresses the criteria applied in the EFSS for accepting jobs and workers as representative of
typical R&R work. Professional abatement workers in the EFSS did wear respirators and follow
abatement personal hygiene procedures to protect themselves. However, they did not follow
standard abatement procedures, such as use of wet methods, and were instructed to perform the
tasks as they are typically conducted in an unregulated environment. For example, demolition
was conducted dry with hammers and crow bars, and sawing was conducted dry with a circular
saw and no HEP A attachment. Since no dust minimization procedures were used, the work was
considered representative of typical renovation and remodeling work. On the other hand,
available data sources from professional abatement work that did involve dust minimization were
not included in any data summaries.
Several comments related to clarification of the terms "surface preparation" and "paint
removal." Although there is certainly overlap between the two activities, there was general
concurrence among all parties consulted during the design of the study that it was important to
distinguish between the two activities. These terms are defined throughout the report to make as
clear as possible the exact type and duration of activity that took place.
Concern was also expressed over the inability to collect both blood-lead and
environmental lead measurements from the same group of workers and/or occupants. Human
subjects review, for both ethical and legal reasons, would not allow measuring blood-lead
concentrations for occupants (young children) before and after conduct of an activity that was
suspected of causing a hazard. For workers, the difficulty in this study was recruiting typical
R&R workers operating in an unregulated environment. For this group of workers, employers
were very reluctant to participate even as the study was conducted. Contractors were concerned
over lawsuits by workers in the event that the study revealed a worker's blood-lead increased as a
result of a specific job they were assigned to. We had very few contractors participating in either
phase of the study. Employees participated in the WCBS largely because of either their own
interest or the interest and encouragement of their national and local union. Gaining access to
work sites for environmental and biological sampling would have required participation of the
contractors, homeowners, and workers. If such sampling was conducted under forced
cooperation, then the results may have been biased. If the study had focused on lead abatement
workers this may not have been a problem, but with a focus on typical R&R workers who were
not, at the time of this study, using worker protection practices, there were many problems
recruiting contractors to participate. In short, the difficulty in recruiting contractors was in
getting at the population of interest: unregulated R&R workers not specializing in lead
abatement.
One reviewer requested more information to show that the QC data are consistent with
the statistical analysis applications and results. As a result of this comment, more documentation
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was added to the reports, including references to appendices and quality assurance project plans;
and inconsistencies in the presentation of QC results were resolved and clarified.
EPA has established a public record for the peer review under administrative record
AR152, "Lead Exposure Associated with Renovation and Remodeling Activities Peer Review."
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.
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2.0 CONCLUSIONS
This chapter presents conclusions drawn from the information obtained in the R&R Study.
For a detailed presentation of study design and results, see Chapters 3 and 4, respectively.
Overall Conclusions
The results of this study indicate that R&R workers may be exposed to high levels of
environmental lead while conducting certain activities in certain environments. However, there is
little evidence of elevated blood-lead concentrations in a population of R&R workers who
conduct a wide variety of activities. Elevated blood-lead concentrations are defined as
concentrations above 40 |ig/dL, the current Occupational Safety and Health Administration
(OSHA) level at which full medical surveillance of a worker is required. It is possible that
specialized groups of R&R workers exist who may be more highly exposed, for example, workers
specializing in historic renovations. However, the R&R study included workers in cities with
documented lead problems who were conducting a significant amount of work in older buildings.
In this regard, study results were weighted toward highly exposed general R&R workers.
However, only one out of 581 participating workers had a blood-lead concentration greater than
40 |ig/dL. Only seven out of 581 participating workers had a blood-lead concentration greater
than 25 |ig/dL.
Because low blood-lead concentrations were observed among R&R workers, long-term
occupant exposure should be stressed when determining the need for worker training, certification
or educational materials. In this study, occupant exposure was characterized by measuring lead
levels in environmental dust. This study indicates that there is a potential for disturbing significant
amounts of lead during R&R activities which could result in occupant exposure if appropriate
cleanup and contamination practices are not conducted. However, the extent to which this
translates into an actual internal dose and the resultant health effects are unknown.
Worker Exposure
Airborne lead levels in a worker's breathing zone, representing an average exposure over
the duration that R&R activity was performed, were often very high during many R&R activities.
These levels averaged greater than 100 |ig/m3 (micrograms of lead per cubic meter of air) for
paint removal, interior demolition, and sawing activities, and greater than 49 |ig/m3 for interior
surface preparation and disturbance of the central heating system ductwork. Average levels were
considerably lower (< 20 |ig/m3) for drilling, carpet removal, window replacement, and exterior
surface preparation. Note that these personal exposure measurements reflect only the period of
conducting the specific R&R activity and do not represent average exposures over an 8-hour day
for a worker. In addition, results were based on selected case studies and small sample sizes.
Paint removal, window replacement, and interior demolition were associated with a
statistically significant increase in workers blood-lead concentrations. Significance was
determined at the 0.05 level, meaning that the probability that the increases were only due to
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chance was no higher than 0.05. However, the estimated increase was so small that it is not
meaningful from a practical standpoint.
In general, R&R activities that have the greatest potential for pronounced disturbance of
lead-based paint have the highest potential for generating lead exposure. Paint removal and
demolition activities resulted in the greatest exposure, while carpet removal was associated with
the least exposure. This finding was consistent for both environmental and blood-lead
measurements.
The environmental (airborne) and blood-lead results, however, produce divergent
conclusions when making comparisons to current regulatory standards. In the Environmental
Study, workers were exposed to high levels of airborne lead, often estimated to exceed the OSHA
Permissible Exposure Limit (PEL) of 50 |ig/m3. On the other hand, blood-lead concentrations for
workers in the Blood-Lead study were generally low, with less than 10% of the workers (52 of
581) having a blood-lead concentration greater than 10 |ig/dL, less than 1.5% (7 of 581) with a
blood-lead concentration greater than 25 |ig/dL, and only one worker with a blood-lead
concentration greater than 40 |ig/dL, the level which requires full medical surveillance. Two
factors may help explain this disparity in conclusions:
R&R work is extremely varied, with exposure occurring sporadically and perhaps
infrequently both within and across work days
The study purposely selected buildings with substantial amounts of lead paint for
collecting the environmental measurements.
A survey of 585 union carpenters and persons who worked for independent R&R
contractors indicated that:
The workers conducted a wide variety of R&R activities
90% of the workers did not use a respirator
89% of the workers did not use lead abatement cleanup methods, while 99% did use
broom cleanup
97% of the workers used dry paint removal methods
67% of the workers had not received any materials on lead hazards, and 87% had
received no lead exposure training.
Occupant Exposure
Occupant exposure to lead in buildings was assessed by analyzing samples of dust
deposited as a result of R&R activities. With the exception of carpet removal and drilling into
plaster, all monitored activities deposited considerable amounts of lead, well over the current EPA
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guidance of 100 |ig/ft2 for floors. Paint removal, demolition, sawing, and disturbing central
heating system ductwork were more likely to cause airborne lead to scatter and settle over a
widespread area, while window replacement and drilling confined the disturbed lead to a smaller
area. Simple broom and shop-vacuum cleanup resulted in substantial reduction in the total
amount of lead available to occupants. However, as the distance from the activity increased, the
cleanup left more lead in the dust left behind. In addition, the average amount of lead left behind
after cleanup often remained above EPA's current guidance on bare floor dust levels (100 |ig/ft2).
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3.0 DESIGN OF THE STUDY
The R&R study, conducted from 1993 to 1995, gathered information to address how
R&R workers are exposed to lead while engaged in various types of R&R activities and how they
disturb lead in the process, thereby creating a lead-based paint hazard to building occupants and
other exposed individuals. The initial phase of the R&R study involved an extensive literature
review and information-gathering process to uncover available information on lead exposure
related to R&R. This phase was conducted in concert with the development of EPA guidelines
for R&R "Reducing Lead Hazard When Remodeling Your Home." In addition to the
literature review, over 200 individuals or groups involved in lead research and/or policy-making
were contacted. These contacts included national committees, major trade industries, published
authors, federal and state agencies, academia, and medical institutions. With the exception of
paint removal, little information was available for an exposure assessment of R&R activities. As a
result, new data would be required to address the study objectives. Complete details of the
literature review and information-gathering process are presented in Chapter 2 of the
Environmental Study technical report.
Once the need for further data collection was identified, it was necessary to determine
whether blood-lead or environmental lead would be measured, both of which have been used in
the past to assess human exposure to lead. The advantages and disadvantages of each approach
were considered. A study assessing blood-lead concentrations provides for direct measurement of
an internal (absorbed) dose of lead. However, blood-lead concentrations are associated with
many secondary factors (such as age, nutrition, and smoking) and by historical as well as recent
exposure. A study assessing measurements of lead in the environment (dust, air, or soil) makes a
direct link between R&R activities and measurements of lead disturbance. However, these
measurements serve only as estimates of the amount of lead available for potential inhalation or
ingestion, therefore representing only a potential internal dose to humans.
An optimal study design would involve measuring worker and occupant blood-lead
concentrations and environmental-lead levels before, during, and after conducting R&R activities.
However, measuring blood-lead concentrations before and after an activity was not feasible for
ethical and legal reasons. Measuring environmental lead levels before and after an activity is
complicated by serious recruitment and liability problems, because of the desire to target typical
R&R jobs in an unregulated environment.
The study design approach circumvented these problems by defining two principal data
collection efforts: one characterizing environmental lead disturbance resulting from R&R
activities and the other focusing on the effect of R&R activity on worker blood-lead
concentrations through a retrospective study. A follow-on study to assess the relationship
between incidence of R&R activity and elevated blood-lead concentration in children is currently
in the design stages.
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The overall design and coordination of the R&R study is presented in Figure 1. All
aspects of the field work involved in the R&R study were documented and submitted to both
contractor and EPA Human Subjects Review Committees for approval. All procedures
conducted in this study complied with the requirements of these committees, as specified in the
study's Quality Assurance Project Plan.
RENOVATION AND REMODELING STUDY
Delineation of Scope; Literature Review and Information Gathering
I
Worker Characterization and Blood-
Lead Study (Blood-Lead Study)
Environmental Field Sampling Study
(Environmental Study)
Identify worker groups
and recruit workers
Large R&R
Projects with
Multiple Activities
Target
Activities
Collect blood samples and
questionnaire information
Decision on Assessment Method
Professional judgment
Literature
New field studies
Controlled designed field study
Monitoring field study
Use of other extant data sources
Characterize workers.
Develop relationship between
blood lead levels and activities
Develop relationships between
activities and measurements of
lead in the environment
WCBS
(Blood-Lead Study)
Technical Report
EFSS
(Environmental Study)
Technical Report
R&R Summary Report
Figure 1. Overall Design Structure of the Renovation and Remodeling Study
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3.1 DATA COLLECTION
Environmental Study
The first data collection effort of the R&R study was for the Environmental Study, which
assessed the relative disturbance of exposure to lead created by selected R&R activities. The
Environmental Study focused on monitoring specific R&R activities rather than specific worker
groups for the following reasons:
1. Focusing on activities provided the best understanding of exactly what was causing
the lead exposure.
2. Focusing on activities was the most efficient way to assess a wide variety of R&R
worker groups. Exposure estimates based on worker groups would be applicable
only to the monitored groups. Exposure estimates based on specific activities, on
the other hand, could be combined with worker profile information for any given
worker group to assess that group's exposure. Worker profile information includes
information on the type of activities workers conduct, the type of work practices
and worker protection they use, and the percent of time they work in buildings with
lead-based paint.
3. Exposure estimates based on R&R activities provide information useful in
developing subsequent guidelines for R&R.
Data collected for the Environmental Study focused on six of the ten target activities: removal of
large structures (demolition), window replacement, carpet removal, HVAC repair or replacement,
surface preparation, and repairs with small surface disruption. Exposure associated with paint
removal was not addressed because it could be documented from the literature. Exposures from
exterior siding, wallpaper removal, and exterior soil disruption were not evaluated, because they
were considered of secondary importance by the study design team and the individuals consulted
in the information-gathering phase. It is possible that inferences about exterior siding and exterior
soil abatement may be made from professional judgment and comparison with other activities.
Wallpaper removal is conducted primarily by painters, who were assessed based on other
activities they perform most notably surface preparation and paint removal.
The Environmental Study was supplemented by an extensive search for other sources of
data that could be used either to fulfill data requirements for a specific activity or to confirm
results obtained in the Environmental Study. A detailed discussion of the Environmental Study
and other sources of data that were uncovered is presented in the Environmental Study technical
report, "Lead Exposure Associated with Renovating and Remodeling Activities: Environmental
Field Sampling Study."
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Blood-Lead Study
The second data collection effort of the R&R study was the Blood-Lead Study. The
Blood-Lead Study involved collecting questionnaire information and blood-lead measurements
from R&R workers to (1) characterize blood-lead concentrations in specific worker groups, (2)
determine if specific worker groups or specific R&R activities are associated with increases in
blood-lead concentrations, and (3) collect information to be used to develop worker profiles. The
Blood-Lead Study was intended to obtain information independent from the Environmental Study
that would provide a direct measure of health effects on worker exposure to lead and to validate
the results of the Environmental Study. Target R&R activities examined in the Blood-Lead Study
included removal of large structures (demolition), window replacement, carpet removal, HVAC
repair or replacement, and paint removal/surface preparation. Post-activity cleanup was also
assessed. A detailed discussion of the Blood-Lead Study is available in the Blood-Lead Study
technical report, "Lead Exposure Associated with Renovating and Remodeling Activities:
Worker Characterization and Blood-Lead Study."
3.2 ENVIRONMENTAL STUDY DESIGN
The overall purpose of the Environmental Study was to assess lead disturbance and
exposure associated with various types of R&R activities by measuring lead in air and dust. The
Environmental Study was conducted in five locations (Baltimore, Maryland; Columbus, Ohio;
Oakland, California; St. Louis, Missouri; and Denver, Colorado). A total of 90 personal exposure
results were reported in this study, representing each execution of a particular R&R activity
within a dwelling unit by one of the 31 participating R&R workers. A total of 556 settled dust
samples were collected from floors and window components in the vicinity of an activity.
3.2.1 Objectives
The objectives of the Environmental Study were to:
1. Characterize personal exposure to airborne lead for workers during the performance
of different R&R target activities and combinations of activities, and determine if
worker exposure to airborne lead during those activities exceed 50 |ig/m3 (the
OSHA Permissible Exposure Limit on the average micrograms of lead per cubic
meter of air within the worker's personal breathing zone).
2. Characterize the amount of lead disturbed that settles on building surfaces within a
specified period following completion of the R&R activity.
3. Characterize the extent that lead disturbance and exposure are affected by various
factors such as distance from the activity and pre-activity measures of lead in the
building environment.
12
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3.2.2 Sampling
Although the activities, buildings, and, in some instances, types of samples differed for
each category of activities, the design and protocol for all environmental sampling were similar.
In general, for each monitored R&R activity, buildings containing lead-based paint suitable
for typical application of the activity were selected. Environmental measurements of lead were
taken before, during, and after conducting the target activity. The measurements taken in the
Environmental Study include:
1. Personal Air Samples. Measures of airborne lead concentration within each
worker's personal breathing zone during the activity period were obtained by taking
air samples through a cassette filter mounted on the worker's lapel. An air sampler
pump was used to take the sample. The activity period was defined for each specific
R&R activity, but generally included immediate preparing for the activity,
conducting the activity, and cleaning up. For each worker, the average exposure
over the duration of the activity period was calculated in |ig/m3.
2. Settled Dust Samples. Settled dust samples were taken either from stainless steel
dustfall collectors or from selected areas, such as floors, window sills, window
wells, and carpets. Samples were collected at varying distances from the surfaces
disturbed by the activity. Lead loadings from settled dust samples were measured as
indicators of the amount of lead disturbed by the activity and made available as a
potential exposure to occupants.
Difficulties in recruiting workers in "real-world" R&R jobs, along with cost constraints
and the wide variety of R&R work practices and building characteristics, made it impossible to
obtain a statistically-based representative sample for exposed populations and defined jobs.
Therefore, the Environmental Study focused on "case studies" that were "not atypical" of R&R
work as it is currently conducted. Two different approaches were taken to characterize these case
studies:
1. Monitoring "real-world" R&R jobs as they occurred in the field.
2. Monitoring controlled, experimentally designed simulations of specified R&R
activities in vacant buildings.
In the latter approach, the type, quantity, and characteristics of the activity were specified
by the design team. The activity was conducted in buildings in the field by experienced workers
who were contracted to perform the work. In this environment, simulated target activities and
generic R&R tasks (e.g., cutting and drilling) were conducted to measure the lead disturbed by
these activities.
13
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3.3 BLOOD-LEAD STUDY DESIGN
The Blood-Lead Study involved a targeted survey of two groups of workers (carpenters
and employees of independent contractors) in two cities (Philadelphia, Pennsylvania, and St.
Louis, Missouri). The collected data included:
1. Worker blood samples that were chemically analyzed for lead
2. Questionnaire data that were used to characterize the workers and understand
differences in blood-lead concentrations among them.
3.3.1 Objectives
The primary goal of the Blood-Lead Study was to collect data that would permit an
assessment of the relationship between R&R activities and actual human exposure. The
objectives of the study were to:
1. Determine the relationship between blood-lead concentrations and work practices or
activities performed by R&R workers, after controlling for other factors that may
affect worker blood-lead concentrations.
2. Determine whether the blood-lead concentrations of R&R workers in specific
worker groups differ after adjusting for other factors that may affect worker blood-
lead concentrations.
3. Gather information on the types of work activities and work practices in which R&R
workers engage.
3.3.2 Survey Design
The target population for the Blood-Lead Study consisted of two groups of R&R
workers:
Union carpenters
Employees of independent, non-union contractors.
Carpenters were chosen because of the wide variety of R&R activities they perform.
Carpenters represent the generalists of the R&R industry, considered by some to comprise the
backbone of the industry. Independent, non-union contractors were chosen because a large
portion of the R&R business is conducted by these workers, and their approaches and practices
may differ from union contractors. Initially, laborers were targeted as a third group, as they can
be considered among the most highly exposed groups of R&R workers. For example, tearing
down a wall or ceiling (rip and strip) is often performed by general laborers using pick and sledge
hammer techniques. However, their union, although initially cooperative, elected not to
participate in the study. As a result, it was not possible to construct a sampling frame of laborers.
14
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Time and resource constraints prevented a nationally representative sample of workers
from being selected in the Blood-Lead Study. Instead, the study targeted workers in two cities:
St. Louis and Philadelphia. These cities were selected because of the support and cooperation of
local union leadership, and because a large number of children with elevated blood-lead
concentrations have been found in both cities. Elevated blood-lead concentrations in children
were taken as an indication of potential lead exposure to workers.
Sampling frames were defined separately for each group of workers. The sampling frame
for the union carpenters was based on a list of current union members provided by the United
Brotherhood of Carpenters and Joiners of America (UBC) leadership in each city. The list of
potential respondents for employees of independent, non-union contractors was compiled by
researching the local construction/remodeling market in each city. Information for potential
independent workers was obtained from the National Association of Home Builders, phone
books, newspaper advertisements, public service announcements, and referrals by other workers.
Sampling methods differed for union and non-union workers. Workers from union
membership lists were randomly sampled for participation in the study. Most of the non-union
workers were recruited from advertisements in local newspapers.
3.3.3 Data Collected
Two questionnaires were used in the Blood-Lead Study: a telephone screening interview
and a self-administered questionnaire. The purpose of the telephone screening interview was to
determine eligibility of the selected workers, to recruit workers for participation in the main study,
and to collect preliminary information on targeted work activities. Eligible workers were initially
requested to come to a centralized location for collection of blood samples and questionnaire
information. If the subject was unwilling to come to a central location, an attempt was made to
recruit that person for data collection in his or her home. The vast majority of participants were
willing to travel to the centralized data collection centers.
Although the questionnaire was self-administered, an interviewer was available to help the
respondent or to administer the entire questionnaire, if necessary. The questionnaire collected
information relevant to a worker's potential lead exposure: (a) demographics, (b) current and past
work history, (c) personal characteristics and habits, (d) non-work activities, (e) medical history,
and (f) previous training or knowledge about potential lead hazards in the workplace. The
questionnaire was reviewed for consistency and completeness before the respondent left the data
collection center.
Blood was collected immediately following administration of the questionnaire. To
minimize the potential for contamination and to insure comparability to data collected in other
studies, blood samples were collected by venipuncture. Blood samples were taken by trained and
licensed phlebotomists.
15
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3.4 DATA GAPS AND LIMITATIONS
Due to the vast scope of the R&R study as defined by Title X legislation, combined with
time and budget constraints, recruitment difficulties, and human subjects concerns, insufficient
information was available to make inferences on certain areas of interest to the study. Data gaps
that remain include:
1. The R&R study includes no information on the relationship between R&R and
occupant (children) blood-lead concentration. It was originally hoped that the
combination of environmental measurements and worker blood-lead concentrations
could provide sufficient exposure information to address regulatory needs.
However, the blood-lead concentrations of R&R workers were very low, while the
amount of lead distributed in the environment was very high. These conflicting
outcomes imply that environmental lead may be an inadequate surrogate for
measuring worker blood-lead concentration. This, combined with difficulties in
determining a health-based standard for acceptable environmental lead levels, places
more importance on the relationship between R&R and occupant exposure as
measured by blood-lead concentrations. Therefore, a follow-on study will be
conducted to evaluate the impact of the conduct of R&R activities on elevated
blood-lead concentrations in children. This study will be conducted jointly with the
University of Wisconsin and the State of Wisconsin Public Health Department.
2. Exposure of people other than occupants and workers was not assessed. Other
potentially exposed populations include workers' families and residents of
neighboring buildings.
Limitations of the data collected include:
1. The Environmental Study field monitoring work represents a series of case
studies that were not selected by a random sampling scheme. Generalizing the
results of the Environmental Study to a broader population must be based on a
qualitative assessment of how representative the case studies are of that population.
However, no reason was uncovered to believe that the case studies were atypical of
general R&R work as it is conducted in an unregulated environment containing high
levels of lead-based paint.
2. The Blood-Lead Study involved a targeted survey of selected groups of R&R
workers in two cities. Generalizing the results of the Blood-Lead Study to a
broader population must be based on a qualitative assessment of how representative
the targeted surveys are of that population. Again, no reason was uncovered to
suspect that the targeted surveys were atypical of R&R workers conducting a
variety of R&R work in cities with a documented potential for lead exposure
problems.
16
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3. The non-union workers in the Blood-Lead Study were largely recruited through
response to advertisements. Whereas the union members were randomly selected
from a fairly complete sampling frame, non-union workers were recruited mainly
through the use of advertisements in newspapers. The recruitment process included
a telephone survey that collected preliminary data on target activities conducted by
each worker.
4. Measurements of lead distributed into the occupants' environment were collected
before cleanup. The effect of different cleanup methods was measured for two
target activities in the Environmental Study, and data were collected in the Blood-
Lead Study on typical cleanup methods employed by R&R workers. However,
additional information on the extent of typical cleanup would be useful.
5. The focus of the data collected in the Environmental Study was on target
housing. Exposure differences between building environments from a lead
abatement perspective are discussed in EPA's proposed rule 40 CFR Part 745,
"Requirements for Lead-Based Paint Activities," where an argument is made that
public buildings and target housing represent similar exposure environments.
However, there are no data at this time to assess whether environmental exposures
monitored in target housing are representative of environmental exposures
encountered in public or commercial buildings.
17
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4.0 RESULTS: EXPOSURE RELATED TO SPECIFIC R&R ACTIVITIES
A primary focus of the R&R study was to assess potential lead exposures to workers and
building occupants associated with specific R&R activities. Exposure results for R&R target
activities and generic R&R tasks are presented in this chapter. In Chapter 5, information on lead
exposure and worker group activities is combined to assess potential exposure for a variety of
worker groups. This assessment can also be performed for worker groups not directly examined
in the R&R Study.
4.1 WORKER EXPOSURE
The effect of specific R&R activities on lead exposure for workers was examined in two
ways: (1) environmental measurement of airborne lead concentration in the personal breathing
zone of workers during specific activities and (2) estimated change in blood-lead concentration
attributable to conducting specific activities.
4.1.1 Summary Measures of Worker Exposure
Table 1 presents two measures that summarize worker airborne lead exposures associated
with specific R&R activities:
The estimated geometric mean of the distribution of average personal worker
exposures over the duration of R&R activity and its associated 95% confidence
interval.
The estimated percentage of workers whose average lead exposures over the
duration of R&R activity are expected to be greater than 50 |ig/m3, the OSHA PEL.
These statistics are obtained from airborne lead concentrations (|ig/m3) measured through
personal exposure monitoring of participating workers while conducting the activity. The table
includes both R&R target activities and R&R "generic tasks" (i.e., short tasks often conducted as
part of a larger R&R job).
The exposure data summarized in Table 1 represent average airborne exposure for the
worker during conduct of the activity. For the generic R&R tasks the period of activity was quite
brief (as little as 15 minutes). OSHA exposure limits are based on an 8-hour time-weighted
average (TWA), which is an average exposure over a full 8-hour work shift. However, very few
R&R activities are conducted for a full 8-hour work day. Therefore, to measure exposure related
to specific activities, the Environmental Study measured average exposures only for the duration
of an activity. This measurement is equivalent to an 8-hour TWA for a worker only if it is
assumed that the worker conducts the monitored activity for 8 hours in a day. However, a
number of personal exposure measurements in the R&R study were high enough to imply that
conducting the activity for even a short period of time, with no exposure during the rest of the
work day, would result in an 8-hour TWA above the OSHA PEL. For each activity, Figure 2
18
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presents the minimum duration of activity which, on average, would be necessary to achieve an 8-
hour TWA of 50 |ig/m3, based on the limited personal exposure data collected in this study.
Table 1. Summary Measures of Worker Exposure to Airborne Lead
R&R Target Activities
Carpet Removal
Window Replacement
Paint Removal'2' (Hand)
(Power)
Large Structure Removal
(Interior Demolition)
HVAC Work
Surface (Interior)
Preparation'3'
(Exterior)
Generic R&R Tasks141
Drilling into Wood
Drilling into Plaster
Sawing into Wood
Sawing into Plaster
Number of
Workers
Monitored
14
8
6
3
20
4
31
38
7
6
6
2
Estimated
Geometric
Mean
Exposure111
(//g/m3)
7.54
7.48
254.00
571.00
108.00
49.60
58.20
4.33
15.10
6.76
546.00
110.00
95%
Confidence
Interval for
Geometric
Mean
(1.74, 32.6)
(1.13, 49.3)
(23.7, 2720)
(42.9, 7600)
(26.6435)
(11.4, 216)
(2.27, 1490)
(0.408, 46.0)
(4.57, 50.2)
(3.00, 15.3)
(366, 813)
(0, 2.32x106)
Estimated
Percentage of
Workers With
Exposures
Expected to
Exceed 50
//g/m3'1'
14%
6.5%
94%
99%
83%
48%
52%
11%
18%
0%
99%
76%
95%
Confidence
Interval for the
Estimated
Percentage of
Workers
(3%, 43%)
(0%, 50%)
(41%, 100%)
(48%, 100%)
(40%, 99%)
(10%, 90%)
(23%, 80%
(0%, 49%)
(4%, 51%)
(0%, 21%)
(99%, 100%)
(15%, 99%)
111 Exposures represent the average lead exposure over the period in which the activity was conducted.
121 Consists of continuous dry sanding activities (using hand or power methods).
131 Based on data from other sources. Surface preparation consisted of a wide variety of activities including wet
and dry scraping, feathering of edges, and wet and dry sanding to prepare a surface for repainting.
141 It could not be determined from this study how much of the difference between wood and plaster substrates
was due to differences in paint lead loading versus differences in substrate.
19
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Activity or Task
Sanding (Power)
Sawing into Wood
Sanding (Hand)
Sawing into Plaster
Demolition
Surface Prep- Interior
HVAC Work
Drilling into Wood
Carpet Removal
Window Replacement
Drilling into Plaster
Surface Prep - Exterior
8hr
1
These activities would not result in an
estimated geometric mean 8-hour TWA
greater than 50 ug/m3 based on the
observed data.
j 1 1 1 1 1 1 1
i 1 1 1 1 1
Figure 2. Hours of Activity That Would Result in an Estimated Geometric Mean 8-Hour
TWA of 50 //g/m3
Overall, average worker exposure to airborne lead over the duration of performing an
activity was very high for paint removal (i.e., dry sanding), interior demolition, and sawing, and
moderately high for interior surface preparation and disturbance of the central heating system
ductwork. Exposures were lower for drilling, carpet removal, window replacement, and exterior
surface preparation.
The last column of Table 1 presents the estimated percentage of workers performing a
given activity whose average lead exposures over the duration of activity are expected to exceed
50 |ig/m3 (under the conditions of this study). Estimates range from zero percent of workers
during drilling into plaster to 99 percent of workers during power sanding. High percentages
were observed for activities having high disturbance potential, such as sanding, demolition, and
sawing.
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4.1.2 Relationship Between Blood-Lead Concentrations and Target Activities
4.1.2.1 Construction of Statistical Models
A series of statistical models were used to investigate the relationship between worker
blood-lead concentration and how often a worker conducts a specific R&R activity. For each
target activity, a regression model was fitted to the log-transformed blood-lead concentration
using the number of days on which the activity was performed in pre-1950 housing as the primary
independent variable.
Since worker blood-lead concentrations are associated with factors other than the conduct
of specific target activities (e.g., age of worker or worker's home, race, or smoking practices),
each regression model also incorporated these potential confounding factors. The worker
questionnaire collected data on these factors, which were both related (e.g., respirator usage) and
unrelated (e.g., age of worker's home) to R&R activities. Because of the large number of
candidate confounding factors, preliminary analyses were first conducted to select the potential
confounding factors for use in the statistical models.
When all factors were included in the regression model simultaneously, race, education
level, smoking status, age of worker's home, recent R&R work in worker's home, and respirator
usage were most related to worker blood-lead concentrations. In general, the estimated effect of
each factor was anticipated: smokers, blacks, non-high school graduates, workers residing in
older homes, and workers residing in homes that recently underwent R&R tend to have higher
blood-lead concentrations. However, the observed effect associated with respirator usage was
opposite of what was anticipated. The geometric mean of blood-lead concentrations of workers
who wear a respirator was greater than that of workers who do not wear such respirators. One
possible explanation for this result may be the fact that workers who report that they wear
respirators are much more likely to be exposed to lead-based paint than those reporting otherwise.
4.1.2.2 Modeling Results
Table 2 displays, for each target activity, the estimated increase in blood-lead
concentration associated with performing a target activity 10 days per month in pre-1950
buildings. Results are presented only for target activities with an estimated increase in blood-lead
concentration. Results in Table 2 include an estimated base level (i.e., estimate for study workers
who did not perform the given activity in pre-1950 buildings), followed by the estimated level for
workers conducting the activity 10 days per month in pre-1950 buildings. Based on the
covariate-adjusted model described in Section 4.1.2.1, a statistically significant relationship (at an
alpha = 0.05 level) was found only for paint removal/surface preparation. Most importantly, the
estimated increase in blood-lead concentration from the base level was very small (less than one
|ig/dL) for each target activity. The results indicate that even frequent conduct of these activities
would be unlikely to raise worker blood-lead concentrations to a level that is currently considered
a health risk.
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Table 2. Summary Statistics Relating Worker Blood-Lead Concentration to the Frequency of
Conducting Target R&R Activities
Target Activity
Carpet Removal
Window Replacement
Paint Removal/Surface Preparation
HVAC Work
Large Structure Removal (Interior Demolition)
Change in Blood-Lead Concentration (//g/dL)
for Work in pre-1950 Buildings
Level When
. __. Conducting the
Base Level -^ ,.., ^
Activity 10
Days/Month
No estimated increase
4.4 -ğ 4.8
4.3 -ğ 4.8*
4.4 -ğ 4.7
4.3 -ğ 4.7
* Slope parameter estimate was significant at an alpha = 0.05 level.
4.2 OCCUPANT EXPOSURE
Potential exposures to building occupants were addressed by measuring lead in settled
dust resulting from a target activity collected before cleanup activities. Pre-cleanup estimates of
the lead distributed into the occupant's environment are considered bounding estimates that
represent maximum levels of lead that may be left behind for potential occupant exposures.
Table 3 presents three columns of information that address potential occupant exposures.
The first column is an estimate of the average amount of lead (|ig/ft2) deposited by the activity in
a 6' x 1' region extending in a perpendicular direction from the activity. The relationship between
the distance from the activity and the amount of lead deposited on the floor was statistically
characterized for each activity and used to estimate the average amount of lead in the 6' x 1'
region. The estimated amount of lead at 6 feet from the activity is presented in the second column
of Table 3.
The third column of Table 3 shows the amount of activity that caused the lead loadings
presented in the first two columns. In the case of window replacement, HVAC work, and large
structure removal, the listed amount of activity is equivalent to the amount of activity monitored
in the Environmental Study. For the other activities, however, the amount of activity (and the
corresponding estimate of lead loading) has been scaled to a "standard unit of activity" chosen to
be reasonably reflective of real-world R&R activity. The standard unit of activity is further
discussed in the Environmental Study technical report.
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Table 3. Summary Measures of Potential Occupant Lead Exposures that Can Result from
Conducting Target and Generic R&R Activities
Average Lead Loading (//g/ft2) in Settled Dust
(Measured Post-Activity, Before Cleanup)
Estimated Loading in a 6'xl' Region
Extending from the Activity
Estimated Loading
at 6 Feet from
Activity
Standard Unit of
Activity
Target Activity
Carpet Removal
Window
Replacement
Paint Removal
HVAC Work
Large Structure
Removal (Interior
Demolition)
Generic Activity
Drilling into Wood
Drilling into Plaster
Sawing into Wood
Sawing into Plaster
16.9
7,710.0
42,900.0
1,290.0
3,250.0
432.0
34.5
999.0
328.0
in
482
15,500
414
1,530
1.27
0.04
105.00
10.60
100ft2
1 window
no standard unit of
activity
1 room
1 room
10 holes
10 holes
1 linear ft
1 linear ft
No samples were collected at six feet from the activity.
For each R&R activity in which a standard unit of activity was defined (i.e., all but paint
removal), Figure 3 illustrates the relationship between distance extending from the area where the
activity is performed and the amount of lead deposited. The amount of lead is estimated based on
conducting the standard unit of activity.
Table 3 reveals that, with the exception of carpet removal and drilling into plaster, all
monitored activities showed the potential to deposit considerable amounts of lead in the & x 1'
region. Average lead loadings in this region ranged from 328 |ig/ft2 for sawing into plaster to
over 40,000 |ig/ft2 for paint removal (dry sanding).
The estimates of settled dust lead loadings presented in Table 3 assume that the area was
not cleaned up following the activity. To address the issue of how much lead is removed by
cleanup, an additional data collection effort was designed to assess pre- and post-cleanup
measurements of the lead deposited on a fresh linoleum surface after completing two generic
R&R tasks (drilling into wood and dry abrasive sanding). Cleanup was conducted by one of two
methods: broom sweeping and shop-vacuuming. These two methods were selected because
results from the Blood-Lead Study indicate that they are used by the vast majority of R&R
workers (see Section 5.1).
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Window Repl.
Demolition
HVAC Removal
Saw/Wood
Drill/Wood
T | Saw/Plaster
1 ask Drill/Plaster
Carpet Removal Ğ*
Distance (ft)
Note: Results are based on conducting a standard unit of activity (see Table 3).
Figure 3. Estimated Distribution of Dust Lead in a 6' x 1' Region Extending from the
Activity Area for Various Activities
Table 4 presents results from the assessment of cleanup effectiveness. While the lead
loading estimates in Table 3 assume no cleanup has taken place, the results in Table 4 also include
the amount of lead that may be left in an occupant's environment after typical R&R activity and
cleanup. Table 4 results of lead after cleanup may be considered "best-case" because:
1. These estimates represent the amount of lead remaining and the percent reduction
achieved on new linoleum
2. The estimates represent cleanup of the entire area that was contaminated with lead.
The results of this assessment of the effectiveness of cleanup were:
1. Both methods resulted in a substantial reduction in the total amount of lead available
to occupants. Before cleanup, the estimated total amount of lead in a 6' x 1' region
ranged from 4,430 jig to 2,800,000 jig. After cleanup, the total amount of lead
ranged from 232 jig to 48,100 jig, averaging a more than 95% reduction in lead.
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Table 4. The Effect of Cleanup on Reducing Lead Loadings on New Linoleum Floors After
Conduct of Two R&R Activities
R&R
Activity
Drilling
Drilling
Abrasive
Abrasive
Methods of
Cleanup
Broom
Shop-
Broom
Shop-
Time of
Sample
Collection
After the Activity
After the Cleanup
% Reduction
After the Activity
After the Cleanup
% Reduction
After the Activity
After the Cleanup
% Reduction
After the Activity
After the Cleanup
% Reduction
Average Lead
Loading (//g/ft2)
Adjacent to
the Activity
26,700
166
99.4%
73,500
360
99.5%
653,000
1070
99.8%
203,000
808
99.6%
Average Lead
Loading (//g/ft2)
at Six Feet Away
from the Activity111
65
124
(90.8%)
146
123
15.8%
1380
828
40.0%
490
303
38.2%
Negative percentages are indicated with parentheses.
2. Although, on average, more than 95% of the lead disturbed by drilling or sanding was
removed by standard broom or shop-vacuum cleanup, the average amount of lead left
behind after cleanup still often remained above EPA's current guidance of 100 |ig/ft2
for floors.
3. The efficiency of cleanup, as measured by the percent reduction in lead, declines as
distance from the activity increases.
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5.0 RESULTS: EXPOSURE ASSOCIATED WITH SPECIFIC R&R
WORKER GROUPS
As stated in Section 1.1, the information collected in the R&R study is to be used,
primarily, to help determine which worker groups require training or certification because of the
potential lead exposure associated with activities they perform. The exposure assessment strategy
to meet this goal in the R&R study is illustrated in Figure 4.
W
o
R
K
E
R
S
Components of
Exposure Assessment
Exposure
Information on
Decision-Making
TLA Worker
Exposure for
Specific Activity
Environmental Study
or
Effect on Blood-
lead Levels of
Specific Activity
Blood-Lead Study
+
+
Worker
Profile
Information
Blood-Lead Study
Worker
Profile
Information
Blood-Lead Study
or
Worker Group
Blood-lead
Levels
Blood-Lead Study
=
=
Worker Group
Exposure
Estimates
in ug/m 3
Worker Group
Exposure
Estimates
in Increase
in Blood-Lead
Lead Disturbed in
the Occupant's Home
by Specific Activities
Environmental Study
Cleanup and
Work Practices
Information
Blood-lead Study and
Environmental Study
Health
Based
Standard
Data Gap
Occupant
Exposure in
ug/ft2 or Increase
in Blood-Lead
Levels
O
C
c
u
p
A
N
T
S
Figure 4. Exposure Assessment Strategies for R&R Workers and Building Occupants, Along
with Sources of Information in the R&R Study
The strategy involves providing the components of exposure information that can be
combined to make informed decisions concerning potential lead exposures to workers or
occupants. For each component of information shown in the boxes on the left side of Figure 4,
the source of information is listed in the bottom section of the box.
Note that certain components of information in Figure 4 are available to assess any worker
group covered under the Title X legislation. For worker exposure, these components include
average personal air exposure over the duration of performing activity as measured in the
Environmental Study, and the increase in blood-lead concentration related to specific activities as
measured in the Blood-Lead Study. For occupant exposure, these components include the lead
distributed in a 6' x 1' gradient region related to specific activities. Other components of
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information in Figure 4 are applicable only to the specific worker groups examined in the R&R
study. Table 5 presents the number of workers in each worker group who were surveyed in the
Blood-Lead Study. Information for groups other than carpenters, floor layers, and laborers is
based on small sample sizes as indicated in Table 5.
Table 5. The Number of Workers Surveyed Within Each Worker Group in the Blood-Lead
Study
Worker Group
Union Carpenters
Non-Union Carpenters
Floor Layers
Laborers
Supervisors
Painters
Drywall Workers
Window Replacement Workers
Number of
Workers Sampled
159
105
82
56
57
34
64
14
5.1 SUMMARY OF WORKER PROFILE INFORMATION IN THE BLOOD-LEAD STUDY
Questionnaire information was collected from a total of 581 union carpenters and
employees of independent contractors in the Blood-Lead Study. The questionnaire included data
on how often each worker conducted specific target activities in homes of any age and in pre-
1950 homes during the past 30 days. For each activity, workers indicated the number of days that
activity was performed at some point in the day (not necessarily the entire day).
The workers surveyed in the Blood-Lead Study had spent an average of 17 days during
the past month on general R&R, of which 11 were spent in pre-1950 homes. The most frequent
activity performed was cleanup, which occurred on an average of 11 days during the month.
Over all workers, large structure removal occurred on an average of 7 days during the month,
paint removal on 6 days, window or door replacement on 4 days, carpet removal on 2 days, and
HVAC work on 1 day.
Each worker was assigned to a worker group based on his or her job title and job
activities. Table 6 presents, for each worker group, the average number of days a given target
activity was conducted during the past 30 days, as well as, the average number of days that
workers conducted the activity in pre-1950 dwellings. The information in Table 6 indicates that
laborers, drywall workers, non-union carpenters, painters, and window and door replacement
workers spent more than ten days per month performing the target activities in pre-1950
dwellings.
27
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Table 6. Average Number of Days that Included Specific Activities for R&R Workers in the
Blood-Lead Study
Worker
Group
Union
Carpenters
Non-union
Carpenters
Floor Layers
Laborers
Supervisors
Painters
Drywall
Workers
Window
Replacement
Workers
All buildings
Pre-1950
buildings
All buildings
Pre-1950
buildings
All buildings
Pre-1950
buildings
All buildings
Pre-1950
buildings
All buildings
Pre-1950
buildings
All buildings
Pre-1950
buildings
All buildings
Pre-1950
buildings
All buildings
Pre-1950
buildings
Number of Days Per Month That an Activity is
Conducted By the Worker Group
Carpet
Removal
1
0
2
1
6
2
5
4
1
0
3
3
1
1
2
2
HVAC
Work
0
0
2
1
1
0
4
4
0
0
1
1
1
1
2
2
Large Structure
Removal
6
4
9
7
1
0
10
7
7
3
6
4
8
6
11
10
Paint
Removal
2
1
7
6
8
2
9
8
2
1
14
11
4
3
7
6
Window
Replacement
3
2
6
4
1
0
7
6
3
1
5
4
2
2
14
11
Summary statistics on work practices over all workers are presented in the bar charts in
Figure 5. These work practices include respirator usage, previous training on lead issues,
methods of paint removal, and methods of cleanup. Each bar presents a percentage of workers in
the given category.
Overall, 60% of the workers reported that they did not use a dust mask or respirator, 30%
reported using a dust-mask, and 10% reported using a respirator. Among the eight worker
groups, respirator use was most frequent for painters and laborers. Relatively few of the workers
had received formal training on R&R in lead-contaminated environments (13%) or educational
materials on lead exposures (33%). Of the 293 workers who had removed paint during the past
30 days, over 90% reported using dry methods (power or hand sanding, hand scraping) and only
17% reported using wet methods. Wet methods of paint removal were employed most often by
drywall workers and laborers. Of the 482 workers who had performed cleanup during the past 30
28
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days, 99% reported that they used a broom, and only 11% reported using a HEP A vacuum or wet
mop. HEPA vacuum or wet mop methods were employed most often by window or door
replacement workers, painters, and laborers.
100
100
None Dustmask Respirator
Protection Used
100
96.9
Dry Wet Chemical Heat
Paint Removal Method Used
100
Received Received
Materials Training
Previous Training on Lead
Broom Vacuum HEPA/
Wet Mop
Cleanup Method Used
Figure 5. Trends in Work Practices as Reported by Workers in the Blood-Lead Study
5.2 WORKER EXPOSURE
Figure 6 displays a histogram of the blood-lead concentrations across 581 workers
sampled in the Blood-Lead Study. These concentrations were generally low, ranging from (below
the detection limit of) 1 to 55 |ig/dL, with a geometric mean of 4.5 |ig/dL. Less than 10% of the
workers (52 of 581) had blood-lead concentrations greater than 10 |ig/dL, less than 1.5% had
blood-lead concentrations greater than 25 |ig/dL, and only one had a blood-lead concentration
greater than 40 |ig/dL.
29
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-------
Drywall Worker
Painter
Window Replacement
Non-union Carpenter
Union Carpenter
Laborer
Supervisor
Floor Layer
n_uT A 1
n-641 £ J
&9
n.fuT A 1
n-34l £ J
n_nr A i
n-141 y J
n_msr A i
n_inn r A 1
n-HğL f J
n_nt r A i
n-56 1 f J
n cr C A 3
1 ^f J
n-KL f J
8
Blood-lead Concentration (ug/dL)
Figure 7. Geometric Mean of Blood-Lead Concentration (Adjusted for Potential
Confounding Factors) and Associated 95% Confidence Intervals for Each Worker
Group
Table 7. Information for an Assessment of Worker Exposures Associated with Different
R&R Worker Groups
Worker
Group
Union Carpenters
Non-Union Carpenters
Floor Layers
Laborers
Supervisors
Painters
Drywall Workers
Window Replacement
Workers
# Workers
Monitored
159
105
82
56
57
34
64
14
MEASURES OF WORKER EXPOSURES
Geometric
Mean Blood-
Lead Cone.
(//g/dL)
4.5
4.8
2.8
4.1
4.1
5.9
6.1
5.8
95% Confidence
Interval on
Geometric Mean
(4.1, 5.0)
(4.3, 5.4)
(2.5, 3.2)
(3.5, 4.9)
(3.5, 4.8)
(4.8, 7.3)
(5.3, 7.1)
(4.3, 7.9)
Percentage of
Workers That
Use a
Respirator111
4
12
7
23
5
21
2
14
Percentage of
Workers That
Received Some
Lead Training
9
16
9
16
23
21
6
14
Does not include wearing dust masks.
31
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5.3 OCCUPANT EXPOSURE
Table 8 may be used to assess the potential lead exposure to occupants from work
conducted by each of the eight worker groups. As discussed in Section 4.2, potential occupant
exposures were addressed by measuring lead loadings in dust and debris that settled following
completion of an R&R activity but prior to cleanup. Five target activities for which worker
profile information was collected in the Blood-Lead Study are included in Table 8, along with the
estimated average lead loading (per square foot) in a 6' x 1' region extending from the activity.
The lead loading represents the effect of the standard unit of activity as presented in Table 3. For
each worker group, the average number of days in a month that workers within the group
participated in each activity is given, along with the estimated percentage of time that workers in
each worker group use abatement type cleanup methods such as high efficiency particle air
(HEPA) vacuuming or tri-sodium phosphate (TSP) washing.
Table 8. Information for an Assessment of Potential Occupant Exposures Associated with
Different R&R Worker Groups
Worker
Group
Union Carpenters
Non-union
Carpenters
Floor Layers
Laborers
Supervisors
Painters
Drywall Workers
Window
Replacement
Workers
# Workers
Monitored
159
105
82
56
57
34
64
14
R&R ACTIVITIES CONDUCTED BY THE WORKER GROUP
Carpet
Removal
HVAC
Work
Large
Structure
Removal
Paint
Removal
Estimated Average Lead Loading (jug/ft2
6' x V Region Extending From the Act
16.9
1290
3250
42900
Window
Replacement
in a
ivity
7710
Average Number of Days Per Month That the Activity is
Conducted Per Worker
1
2
6
5
1
3
1
2
0
2
1
4
0
1
1
2
6
9
1
10
7
6
8
11
2
7
8
9
2
14
4
7
3
6
1
7
3
5
2
14
Percentage of
Time that
Workers Clean
with HEPA
Vacuum or TSP
0.1
2.4
0.7
11.0
0.1
7.5
3.3
8.5
In making conclusions about the relationship between worker group and potential
occupant exposure, the average number of days in which an activity is performed by a worker
group in pre-1950 homes can act as a weighting factor on the settled dust lead loading for the
activity and, therefore, on potential occupant exposure. For a given worker group, as the average
number of days increases, more weight should be given to the lead loading for the associated
activity. However, other weighting factors need also be taken into account. These factors
include:
32
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The extent to which lead loadings are reduced by post-activity cleanup including the
use of abatement-type cleanup methods. Some of this information is provided in
Table 4 and the last column of Table 8.
The expected amount of activity to be conducted in an occupant's home. For
instance, lead loadings in Table 8 for window replacement represent the effect of
removing one window. Most R&R window replacement jobs would involve more
than one window.
The potential for lead dust and debris to become airborne and scatter over a wide
area. Some activities (such as drilling) result in little lead distributed beyond a six
foot radius while others (such as demolition) have significant potential to contaminate
other areas of the house.
The particle size and bioavailability of the lead disturbed as related to pathways of
exposure (inhalation versus ingestion), effectiveness of cleanup, and an actual applied
dose to occupants.
The uncertainty in all aspects of the occupant exposure information does not allow for
calculation of an overall quantitative "exposure index" to be used in comparing worker groups.
From the results of this study, only a general conclusion can be drawn that there is potential for
significant amounts of lead to be disturbed by R&R activities that may become available for
occupant exposures if appropriate cleanup and containment practices are not conducted.
33
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6.0 REFERENCES
1. U.S. Environmental Protection Agency (EPA), December, 1995. "Lead Exposures
Associated With Renovation and Remodeling Activities: Environmental Field Sampling
Study." (Draft).
2. U.S. EPA, December, 1995. "Lead Exposures Associated With Renovation and Remodeling
Activities: Worker Characterization and Blood-Lead Study." (Draft).
3. 40 CFR Part 745, Requirements for Lead-Based Paint Activities.
4. U.S. EPA, April, 1994. "Reducing Lead Hazard When Remodeling Your Home."
5. U.S. EPA, July 14, 1994. "Agency Guidance on Residual Lead-Based Paint, Lead-
Contaminated Dust, and Lead-Contaminated Soil."
34
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50272-101
REPORT DOCUMENTATION 1. REPORT NO. 2.
PAGE EPA 747-R-96-005
4. Title and Subtitle
Lead Exposure Associated with Renovation and Remodeling Activities: Summary Report
7. Author(s)
Menkedick, J.R., Menton, R.G., Constant, P., Lordo, R.A., Strauss, W.J.
9. Performing Organization Name and Address
Battelle Memorial Institute and Midwest Research Institute
505 King Avenue 425 Volker Boulevard
Columbus, Ohio 43201-2693 Kansas City, Missouri 64110
12. Sponsoring Organization Name and Address
U.S. Environmental Protection Agency
Office of Pollution Prevention and Toxics
401 M Street, S.W.
Washington, D.C. 20460
3. Recipient's Accession No.
5. Report Date
May 1997
6.
8. Performing Organization Rept. No.
10. Project/Task/Work Unit No.
1 1 . Contract(C) or Grant(G) No.
(C) 68-D5-0008
(G)
1 3. Type of Report & Period Covered
Summary Report
14.
15. Supplementary Notes
16. Abstract (Limit 200 words)
The U.S. Environmental Protection Agency, in response to the Residential Lead Based Paint Hazard Reduction Act of 1992 (Title X)
conducted a study of lead exposure associated with renovation and remodeling (R&R) activities. The results of a literature review and two
data collection efforts are reported. The first data collection effort, the Environmental Field Sampling Study (EFSS), collected 90 personal
air samples and 556 settled dust samples to assess potential exposure to workers and occupants from selected R&R activities. The second
effort, the Worker Characterization and Blood-Lead Study (WCBS), collected blood-lead measurements and questionnaire information from
585 R&R workers in two cities. The task length average exposures measured by personal air samples of R&R workers in the EFSS were
often very high (greater than 50 fjg/m3). However, the blood-lead levels from R&R workers in the WCBS were quite low, with only 7 out of
581 workers above 25 fjg/dL and only one out of 581 above 40//g/dL. The settled dust samples indicated that there is potential for
significant amounts of lead to be disturbed by R&R activities, well over the current EPA guidance of 1 00 fjg/ft2 for floors.
17. Document Analysis
a. Descriptors
Lead-based paint, lead hazards, renovation and remodeling, field study, blood-lead measurements, dust-lead, personal exposure
samples, worker certification, worker survey
b. Identifiers/open-ended Terms
Lead, renovation and remodeling, worker exposure, PEM, blood-lead, Title X, dust sampling
c. COSATI Field/Group
18. Availability Statement 19. Security Class (This Report)
Unclassified
Release Unlimited
20. Security Class (This Page)
Unclassified
21 . No. of Pages
43
22. Price
(See ANSI-239.18)
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-35)
Department of Commerce
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