February 15, 1999
EVALUATION OF
SECTION 402 RISK ANALYSIS PROTOCOLS
.. PEER REVIEW DRAFT FINAL REPORT
Technical Branch
National Program Chemicals Division
Office of Pollution Prevention and Toxics
U.S. Environmental Protection Agency
Washington, D.C. 20460
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U.S. EPA DISCLAIMER
This document is a preliminary draft. It has not been released formally by the Office of
Pollution Prevention and Toxics, U.S. Environmental Protection Agency.
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 of
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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
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the information contained herein, beyond any express obligations embodied in the governing
written agreement between Battelle and the United States Government.
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CONTRIBUTING ORGANIZATIONS
The methodology described in this report is part of a task funded by the U.S.
Environmental Protection Agency. The task was managed by the U.S. Environmental Protection
Agency. The task was conducted by Battelle Memorial Institute under contract with the U.S.
Environmental Protection Agency.
Battelle Memorial Institute
Battelle Memorial Institute (Battelle) was responsible for collection of the data, data
management, development of statistical methods, and the writing of this report. The contributing
authors were Ms. Pamela Hartford, Mr. Ying-Liang Chou, Dr. John Kinateder, and Dr. Agnes
Kovacs. Other contributing staff were Ms. Beth Burkhart, Ms. Jan Clark, Ms. Jennifer Groves,
Ms. Julie Holt, Dr. James Ma, Ms. Jill Raudabaugh, Dr. Virginia Sublet, and Ms. Hsing-Chuan
Tsai.
U.S. Environmental Protection Agency
The U.S. Environmental Protection Agency (EPA) funded and managed the task, and
reviewed task documents. The EPA Work Assignment Manager was Ben Lim. The Project
Officer was Sineta Wooten.
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TABLE OF CONTENTS
EXECUTIVE SUMMARY x
1.0 INTRODUCTION 1
1.1 OBJECTIVES 4
1.2 STRUCTURE OF THE REPORT 5
2.0 CONCLUSIONS 6
2.1 OBJECTIVE 1: PROBABILITY OF CORRECTLY IDENTIFYING A LEAD-
BASED PAINT HEALTH HAZARD IN SINGLE FAMILY HOUSING AND
THE COSTS ASSOCIATED WITH THE RISK ASSESSMENT 6
2.1.1 Risk Assessor Costs 6
2.1.2 Performance Characteristic Analysis 7
2.2 OBJECTIVE 2: ASSESSMENT OF ESTIMATORS OF "TRUE"
AVERAGE LEAD LEVELS AND SAMPLING PROTOCOLS USING
ERROR PROBABILITIES 9
2.3 OBJECTIVE 3: ASSESSMENT OF SAMPLING LOCATIONS RISK
ASSESSORS MAY WANT TO TARGET 10
3.0 QUALITY ASSURANCE 11
4.0 DATA SOURCES 13
4.1 ROCHESTER LEAD-IN-DUST STUDY 14
4.2 HEALTH DEPARTMENT DATA SOURCES 16
4.3 RISK ASSESSOR COST INFORMATION 19
5.0 STATISTICAL METHODS 21
5.1 OBJECTIVE 1: PROBABILITY OF CORRECTLY IDENTIFYING A LEAD-
BASED PAINT HEALTH HAZARD IN SINGLE FAMILY HOUSING AND
THE COSTS ASSOCIATED WITH THE RISK ASSESSMENT 22
5.1.1 Risk Assessor Cost Information 22
5.1.2 Performance Characteristics 25
5.2 OBJECTIVE 2: ASSESSMENT OF ESTIMATORS OF THE TRUE
AVERAGE LEAD LEVELS AND SAMPLING PROTOCOLS USING
ERROR PROBABILITIES 33
5.2.1 Key Analysis Assumptions 33
5.2.2 Error Probability Calculations 34
5.2.3 Within-House Variation Calculations 36
5.2.4 Data Used to Characterize Within-House Variation 36
5.2.5 Error Probability Calculations Associated with
"Simple" and "Compound" Lead Hazard Screens 38
5.3 OBJECTIVE 3: ASSESSMENT OF SAMPLING LOCATIONS RISK
ASSESSORS MAY WANT TO TARGET 40
5.3.1 Data Used in the Analysis 40
5.3.2 Correlation Analysis 41
5.3.3 Pathways Analysis 42
6.0 RESULTS 46
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TABLE OF CONTENTS
(Continued)
Page
61 OBJECTIVE 1: PROBABILITY OF CORRECTLY IDENTIFYING A LEAD-
BASED PAINT HEALTH HAZARD IN SINGLE FAMILY HOUSING AND
THE COSTS ASSOCIATED WITH THE RISK ASSESSMENT 46
6.1.1 Risk Assessor Cost Summaries 46
6.1.2 Performance Characteristic Analysis Results 58
6.2 OBJECTIVE 2: ASSESSMENT OF ESTIMATORS OF THE TRUE
AVERAGE LEAD LEVELS AND SAMPLING PROTOCOLS USING
ERROR PROBABILITIES 78
6.2.1 Within-House Variance Components 79
6.2.2 Effect of the Use of the Geometric Mean, Arithmetic
Mean, and Maximum Value on the Error Probabilities 80
6.2.3 Effect of the Number of Media Samples Collected 93
6.2.4 Effect of the Interim Guidance and Proposed Rule
Standards on the Error Probabilities 95
6.3 OBJECTIVE 3: ASSESSMENT OF SAMPLING LOCATIONS RISK
ASSESSORS MAY WANT TO TARGET 97
6.3.1 Correlation Analysis Results 97
6.3.2 Pathways Model Results 98
7 0 DISCUSSION 100
7.1 PERFORMANCE CHARACTERISTICS AND ERROR PROBABILITIES 100
7.2 PATHWAYS ANALYSIS 101
7.3. PROPOSED RULE COMPARED TO THE INTERIM GUIDANCE 102
8.0 REFERENCES 103
LIST OF APPENDICES
APPENDIX A Section 402 Guidance for Risk Analysis Procedures A-1
APPENDIX B Summary of the Activities of a Risk Assessor as Specified in the Risk
Assessor Curriculum B-1
APPENDIX C Risk Assessor Cost Questionnaire C-1
APPENDIX D Choices for a Risk Assessor D'1
APPENDIX E Blood and Environmental Sampling Standards E-1
APPENDIX F Data Set Criteria M
APPENDIX G Summary Tables and Figures G'1
APPENDIX H Summary Error Probability Tables and Graphs for the Interim
Guidance Standards H'1
APPENDIX I Summary Error Probability Tables and Graphs for the Proposed Rule
Standards '"1
APPENDIX J Summary of the Pathways Analysis for the Rochester Lead-in-Dust
Study Data J'1
APPENDIX K Documents Used In Obtaining Health Department Data K-1
APPENDIX L Sampling Distributions of the Statistics and Error Probability
Calculations L"1
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TABLE OF CONTENTS
(Continued)
LIST OF TABLES
Page
Table ES-1. Environmental Standards Used in the Analyses xii
Table 1-1. Environmental Standards Used in the Analyses 3
Table 2-1. Summary of the Performance Characteristics when Dust Samples are
Obtained from Four Rooms and Two Rooms in a Home 8
Table 4-1. Distribution of the Year Homes were Built and the Age of the Children for the
Rochester Lead-in-Dust Study 15
Table 4-2. Distribution of the Age of the Children in the Rhode Island Department of
Health Data 1j|
Table 5-1. Definitions of Performance Characteristics 25
Table 5-2. Sampling Protocol Group A: Assessing the Impact of Dust Sampling from
Specific Rooms Included in a Risk Assessment 30
Table 5-3. Sampling Protocol Group B: Assessing the Impact of Using Different
Summary Measures to Characterize Dust Samples for a Risk Assessment 31
Table 5-4. Sampling Protocol Group C: Assessing the Outcome of a Lead Hazard
Screen Versus a Risk Assessment 31
Table 5-5. Summary of the Statistics Calculated to Characterize the Protocols 32
Table 5-6. Data Used for the Calculation of the Within-House Components of Variation 37
Table 5-7. Rooms and Types of Components Sampled in the Rochester Study 41
Table 6-1. Average Total Cost of a Risk Assessment, Lead Hazard Screen,
Inspection, and Risk Assessment/Inspection With and Without Extremely
High Costs 48
Table 6-2. Average Cost Per Environmental Sample {Dust, Soil, Water) Collected for a
Risk Assessment, Lead Hazard Screen, Inspection, and Risk
Assessment/Inspection, By Contractor • • 54
Table 6-3. Average Cost Per Sample Collected for Sampling Performed by a Certified
Risk Assessor During a Risk Assessment, Lead Hazard Screen, Inspection,
or Risk Assessment/Inspection For All Contractors 55
Table 6-4. The Average Number of Environmental Samples Collected for a Risk
Assessment, Lead Hazard Screen, Inspection, and Risk
Assessment/Inspection, Over All Media, By Contractor 57
Table 6-5. Average Number of Samples Collected for Sampling Performed by a
Certified Risk Assessor During a Risk Assessment, Lead Hazard Screen,
Inspection, or Risk Assessment/Inspection For All Contractors 58
Table 6-6. Sampling Protocol A: Assessment of the Impact of the Number and Type
of Rooms in Which Dust Wipe Samples are Collected on the Outcome of a
Full Risk Assessment, Using the Interim Guidance Standards (XRF Paint
Samples from Surfaces With >5% Deteriorated Paint) 60
Table 6-7 Sampling Protocol A: Assessment of the Impact of the Number and Type
of Rooms in Which Dust Wipe Samples are Collected on the Outcome of a
Full Risk Assessment, Using the Proposed Rule Standards (XRF Paint
Samples from Surfaces With >5% Deteriorated Paint) 61
Table 6-8. Sampling Protocol A: Summary of the Assessment of the Impact of the
Number and Type of Rooms in Which Dust Wipe Samples are Collected on
the Outcome of a Risk Assessment, Using the Interim Guidance and
Proposed Rule Standards (No Soil and Paint Sampling Included) 62
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TABLE OF CONTENTS
(Continued)
Page
Table 6-9. Number of Additional Homes that Failed the Dust Standards when the
Entryway and Kitchen were Sampled
Table 6-10. Sampling Protocol B: Assessment of the Impact of Various Methods of
Characterizing Dust Wipe Samples Obtained in a Full Risk Assessment,
Using the Interim Guidance Standards (XRF Paint Samples from Surfaces
With >5% Deteriorated Paint) •
Table 8-11. Sampling Protocol B: Assessment of the Impact of Various Methods of
Characterizing Dust Wipe Samples Obtained in a Full Risk Assessment,
Using the Proposed Rule Standards (XRF Paint Samples from Surfaces
With >5% Deteriorated Paint)
Table 6-12. Sampling Protocol B: Assessment of the Impact of Various Methods of
Characterizing Dust Wipe Samples Obtained in a Full Risk Assessment,
Using the Interim Guidance and Proposed Rule Standards (No Soil and
Paint Sampling) ',' 'J " '
Table 6-13. Sampling Protocol C: Comparison of Full Risk Assessment Outcome to a Lead
Hazard Screen Outcome, Using the Interim Guidance Standards {XRF Paint
Samples From Surfaces With >5% Deteriorated Paint) 69
Table 6-14. Sampling Protocol C: Comparison of Full Risk Assessment Outcome to a
Lead Hazard Screen Outcome, Using the Proposed Rule Standards (XRF
Paint Samples From Surfaces With >5% Deteriorated Paint) 70
Table 6-15. Summary of the Assessment of Lowered Soil and Dust Standards
Associated with the Proposed Rule Relative to the Interim Guidance 73
Table 6-16. Summary of the Assessment of the Exclusion of Window Well Sampling
Under the Proposed Rule Relative to the Interim Guidance 74
Table 6-17. Summary of the Comparison of the Interim Guidance Results and
Proposed Rule Results for a Full Risk Assessment 76
Table 6-18. Sampling Protocol A: Comparison of the Estimated Costs of a Full Risk
Assessment when Dust Samples are Taken in Two, Three, and Four
Rooms
Table 6-19. Sampling Protocol C: Comparison of the Estimated Cost of a Full Risk
Assessment Outcome to the Cost of a Lead Hazard Screen Outcome 78
Table 6-20. Estimated Within-House Components of Variation for Each Data Source,
Media, and Component
Table 6-21. Comparison of Risk Assessment and "Compound" Lead Hazard Screen
Error Probabilities for Each Statistic Over a Range of Assumed "True"
House Lead Levels For Two. Three, and Four Floor Dust Samples Using
the Interim Guidance Standards - Variance Components from the
Rochester Study Data 86
Table 6-22. Comparison of Risk Assessment Error Probabilities for Each Statistic Over
a Range of Assumed "True" House Lead Levels For TWO, Three, and Four
Window Sill Dust Samples Using the Interim Guidance Standards -
Variance Components from the Rochester Study Data 87
Table 6-23. Comparison of Risk Assessment and "Compound" Lead Hazard Screen
Error Probabilities for Each Statistic Over a Range of Assumed "True"
House Lead Levels For Two. Three, and Four Window Well Dust Samples
Using the Interim Guidance Standards - Variance Components from the
Rochester Study Data
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TABLE OF CONTENTS
(Continued)
Page
Table 6-24. Comparison of Boundary and Foundation Two. Three, and Four Soil
Sample Error Probabilities for Each Statistic Over a Range of Assumed
"True" House Lead Levels Using the Interim Guidance Standards -
Variance Components from the CAP Study Data 89
Table 6-25. "Simple" Lead Hazard Screen Error Probabilities for Each Statistic Over a
Range of Assumed True House Lead Levels For Two. Three, and Four
Floor and Window Well Dust Samples Using the Interim Guidance
Standards - Variance Components From the Rochester Lead-in-Dust Study
Data 92
Table 6-26. Summary of the Type I Error Probabilities when Two. Three, and Four
Floor. Window Sill, and Window Well Dust and Soil Samples are Collected
for a Risk Assessment Under the Interim Guidance Standards - Variance
Components From the Rochester Lead-in-Dust Study Data 94
Table 6-27. Summary of Type I Error Probabilities for Two, Three, and Four Floor Dust,
Window Sill Dust, and Soil Samples Under the Interim Guidance and
Proposed Rule Standards - Variance Components from the Rochester
Lead-in-Dust Study Data and the CAP Study Data 95
Table 6-28. Summary of Type II Error Probabilities for Two, Three, and Four Floor
Dust, Window Sill Dust, and Soil Samples Under the Interim Guidance and
Proposed Rule Standards - Variance Components from the Rochester
Lead-in-Dust Study Data and the CAP Study Data 96
Table 7-1. Probabilities Calculated for the Performance Characteristic and Error
Probability Analysis 10°
LIST OF FIGURES
Figure 5-1. Example of an Ideal Situation When 100% is Achieved For All Four
Performance Characteristics 26
Figure 5-2. Example of a Situation Where the Negative Predictive Value and
Sensitivity Equal 100%, but the Positive Predictive Value and
Specificity are Less than 100% 27
Figure 5-3. Pathways of Lead Exposure Investigated Using the Rochester Study
Data 42
Figure 6-1. Total Costs for a Risk Assessment, Inspection, Lead Hazard Screen,
and a Risk Assessment/Inspection 47
Figure 6-2. Estimated Costs ($) of the Visual Assessment, Typical Environmental
Sampling, and the Risk Assessment Report for a Risk Assessment 50
Figure 6-3. Estimated Costs ($) of the Visual Assessment, Typical Environmental
Sampling, and the Lead Hazard Screen Report for a Lead Hazard
Screen • • • • 51
Figure 6-4. Estimated Costs ($) of the Visual Assessment, Typical Environmental
Sampling, and the Inspection Report for an Inspection 52
Figure 6-5. Estimated Costs ($) of the Visual Assessment, Typical Environmental
Sampling, and the Risk Assessment/Inspection Report for a Risk
Assessment/Inspection 53
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February 15, 1999 viii
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TABLE OF CONTENTS
(Continued)
Page
Figure 6-6. Comparison of Risk Assessment and "Compound" Lead Hazard Screen
Geometric Mean, Arithmetic Mean, and Maximum Value Error
Probabilities for Two Floor. Window Sill, and Window Well Dust
Samples using the Interim Guidance Standards - Variance Components
from the Rochester Lead-in-Dust Study Homes 82
Figure 6-7. Comparison of Risk Assessment Geometric Mean, Arithmetic Mean,
and Maximum Value Error Probabilities for Two. Three, and Four Soil
Samples Collected. Using the Interim Guidance Standards - Variance
Components from the Foundation of the Home and Boundary of the
Property in the CAP Study Data 83
Figure 6-8. Comparison of Risk Assessment and "Compound" Lead Hazard Screen
Geometric Mean, Arithmetic Mean, and Maximum Value Error
Probabilities for Two Floor. Window Sill, and Window Well Dust
Samples Using the Interim Guidance Standards - Variance Components
from the Rhode Island Department of Health Homes 84
Figure 6-9. Comparison of Risk Assessment Geometric Mean, Arithmetic Mean,
and Maximum Value Error Probabilities for Two. Three, and Four Soil
Samples Collected from Side of the House/Foundation for Homes Using
the Interim Guidance Standards - Variance Components from the
Rhode Island Department of Health Data 85
Figure 6-10. Comparison of "Simple" Lead Hazard Screen Geometric Mean,
Arithmetic Mean, and Maximum Value Error Probabilities for Two Floor
and Window Well Dust Samples Using the Interim Guidance Standards
- Variance Components from the Rochester Lead-in-Dust Study
Homes 91
Figure 6-11. Statistically Significant Pathways of Lead Exposure Using the
Rochester Study Data 99
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EXECUTIVE SUMMARY
The Residential Lead Based Paint Hazard Reduction Act of 1992 (Title X) required EPA
"to ensure the availability of a trained and qualified workforce to identify and address lead-based
paint hazards, and to protect the general public from exposure to lead hazards" [5]. As required
by Title X, EPA published a final rule for Section 402 of the Toxic Substances Control Act
(TSCA) [4], in August, 1996, which detailed the requirements for individuals conducting lead-
based paint activities. This rule requires that a risk assessment, lead hazard screen, inspection,
and risk assessment/inspection be performed by certified individuals. While many aspects of the
sampling and inspection are prescribed for the risk assessor, there are other areas where the
certified individual has the freedom to use personal judgement in specifying the extent of
sampling during a risk assessment, including sampling location and number of samples taken.
The purpose of this task was to characterize the probability of a certified risk assessor
correctly identifying a lead-based paint hazard in single family housing units when different
choices are made as allowed by the Section 402 regulations. Specifically, the choices assessed
were the number of rooms in which dust samples were collected, and specific rooms in which to
sample dust. In addition, the method with which to characterize the dust and soil samples was
assessed by evaluating the ability of three statistics, geometric mean, arithmetic mean, and
maximum value, to characterize the dust and soil levels found in the home. Three specific
objectives were laid out to assess the choices a risk assessor may make and to assess aspects of
the Section 402 rule:
1. Characterize how different sampling protocols affect a) the probability of correctly
identifying a health hazard (defined for the purposes of this analysis as the presence
of a child with a blood-lead concentration greater than or equal to 10 ug/dL) in single
family housing (performance characteristic analysis^ and b) the cost of the assessment
(cost analysis).
2. Characterize for a risk assessment and lead hazard screen a) how well different
estimators and sampling protocols estimate the true average lead levels in a single
family home, and b) the error probabilities associated with concluding that a home is
above or below a given media standard for different estimators and sampling
protocols (error probabilities analysis').
3. Assess which sampling locations a risk assessor may want to target in order to assure
that they are best evaluating the potential lead hazard to a child (pathways analysis).
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Objective 1 was assessed using two different sets of information. The first set was the
risk assessment cost information collected from nine risk assessors in nine different States. The
second set was calculated information on four performance characteristics: sensitivity,
specificity, positive predictive value (PPV), and negative predictive value (NPV). Briefly,
a) Sensitivity is the probability a home fails an assessment given that there is a child
with an elevated blood-lead concentration in the home, . *
T
b) Specificity is the probability a home passes the assessment given that there is a child
with a low blood-lead concentration in the home,
c) PPV is the probability the child in the home has an elevated blood-lead concentration
given that the home failed the assessment, and
d) NPV is the probability that the child in the home has a low blood-lead concentration
given that the home passes the assessment.
The Objective 2 analysis was assessed using two types of error probabilities: Type I
(False Positive) error and Type II (False Negative) error. Each is briefly defined as follows:
a) Type I (False Positive) error is the probability that a home fails the assessment given
that the home should have passed the assessment and
b) Type II (False Negative) error is the probability that a home passes the assessment
given that the home should have failed the assessment.
Finally, the Objective 3 analysis was performed using Pearson correlation coefficients
and structural equation models (pathways models).
The Objective 1 and 2 analyses used the media (dust and soil) and component (floors,
window sills, and window wells) standards listed in EPA's 403 Interim Guidance and EPA's 403
Proposed Rule and shown in Table ES-1 to calculate the performance characteristics and the
error probabilities. Currently, the guidance for the Section 402 activities is the Section 403
Interim Guidance and the HUD Guidelines. When the Section 403 Proposed Rule becomes final,
the guidance in this document will supersede the guidance in the Section 403 Interim Guidance
document. The analyses assessed the impact the standards in the Proposed Rule may have on the
outcome of risk assessments, compared to the outcomes observed under the Interim Guidance
standards.
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Table ES-1. Environmental Standards Used in the Analyses.
Hazard Standards for Comparison
EPA Interim 403 Guidance
EPA Proposed 403 Rule
Dust Wipe
Floors
a 50j/g/ft2*
Window Sills
SOOi/g/ft1
2 250 //g/ft2
Window Troughs
*800j/g/ft2
None
Soil (Bare)
5,000 ppm
2.000 ppm
Painted components with areas
of deteriorated lead-based
paint *•
Any deterioration present
1) *2ft2 deteriorated for large interior
components; 2) 210 ft2 deteriorated
for large exterior components; or 3)
210% of the surface deteriorated for
small components
* Floor dust wipe samples from uncarpeted floors only.
*• The statutory definition of lead-based paint is paint with 2 1.0 mg/cm2 lead or 2 0.5% lead by weight.
Data from the Rochester Lead-in-Dust study, the Comprehensive Abatement
Performance (CAP) study, the Rhode Island Health Department, and nine risk assessors were
used in one or more of the analyses.
For Objective 1, only the Rochester Study data were used in the performance
characteristic analysis, and the cost information from the surveyed risk assessors was used to
evaluate the cost of risk assessments and lead hazard screens. Note that special emphasis was
given to the sensitivity and NPV in the performance characteristic analysis. The sensitivity
focuses on the home media failure rate when the child is known to have an elevated blood lead
concentration, while the NPV focuses on the probability of a child having a low blood lead
concentration when it is known that the media samples have passed the standards. The results
indicated the following:
• The estimated cost of a risk assessment in areas where they are commonly performed
was $435, while the average cost for a lead hazard screen was $169.
• Collecting dust samples from the bedroom and play area provided as much
information as collecting dust samples from the bedroom, play area, kitchen, and
interior entryway;
• Under the Interim Guidance standards, the maximum value of the dust and soil
samples yielded the highest sensitivity and NPV while under the Proposed Rule the
arithmetic mean of the dust and soil samples had the highest sensitivity and NPV;
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February 15, 1999 xii
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• The exclusion of a window v/ell standard in the Proposed Rule did not affect the
ability of the risk assessment to identify health hazards. The exclusion could impact
the outcome of a lead hazard screen. Section 402 only prescribes that "windows!' be
sampled for a lead hazard screen depending on the choices a risk assessor may make.
The 1995 HUD Guidelines interpreted "windows" as sampling only the,window
wells and not the window sills. As a result, if a risk assessor combines the HUD "
Guideline interpretation of the.lead hazard screen with the Proposed Rule standards
they will not sample anv windows. Not sampling any windows forces the lead hazard
'screen to be based solely on floor dust and paint. Under the Proposed Rule, this
screen is not as discriminating as the screen that samples the window sill.
• The combination of using the arithmetic mean to characterize the dust and soil
samples and the lower standards, under the Proposed Rule, seems to provide for an
assessment which maintains the ability to identify health hazards while failing fewer
homes that would have failed under the Interim Guidance standards.
The Rochester Study .data, CAP Study data, and Rhode Island Department of Health data
were used in the Objective 2 analysis. The results show:
• Type I (false positive) error rates were highest when the maximum value was used to
characterize the true media average lead level and lowest when the geometric mean
was used. The opposite was true for the Type II (false negative) error rates. The
arithmetic mean error rates were always between the maximum value and geometric
mean error rates;
• The Type I (false positive) and Type II (false negative) error rates were usually over
25% for all three statistics-geometric mean, arithmetic mean,jind maximum value -
when the true media lead levels were assumed to be within 20% of the media
standard. This indicates a large area where incorrect decisionsTnay be made,
regardless of the method used to characterize the dust and soil samples;
• The Type I error probabilities increased as the number of samples collected for dust
and soil increased, when the maximum value was used to characterize the dust and
soil samples. The Type I error probabilities were much less dependent on the number
of samples collected for the arithmetic mean and geometric mean;
• The combination of lowering the dust and soil standards and using the arithmetic
mean to characterize these samples, as written in the Proposed Rule, seems to have
improved the discrimination of the risk assessment conducted under the Interim
Guidance by reducing the Type I and Type n error probabilities.
Only the Rochester Study data were used in the Objective 3 analysis. This analysis
showed:
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• The log-transformed blood-lead concentrations were positively correlated with the
log-transformed dust-lead loadings on the floors, window sills, and window wells in
the bedroom, kitchen, and play area;
• The log-transformed kitchen and play area window well dust-lead loadings, interior
entryway and the kitchen floor dust-lead loadings, and play area and bedroom floors
dust-lead loadings were significantly correlated.
• The play area floor dust was the only statistically significant pathway of
environmental lead to the child's blood. This indicates that the risk assessor may
want to collect samples from the child's play area floor to best assess a potential lead
hazard to the child.
o
• The window well dust-lead was a statistically significant pathway of lead to the
window sill dust in both the bedroom and play area. This indicates that sampling
either the window well or window sill may provide enough information about the
lead hazard from the windows.
In summary, sampling dust from the bedroom and play area provided the same
information as sampling dust from the bedroom, play area, kitchen, and interior entryway;
increasing the number of dust samples collected only affected the outcome of a risk assessment
when the maximum value was used to characterize the dust samples; sampling the play area
floors provided the best indication of the lead hazard available to the child; removing the window
wells from the risk assessment did not affect the ability of the assessment to identify lead
hazards; and the combination of the lower soil and dust standards and the use of the arithmetic
mean to characterize these samples, as described in the Proposed Rule, provides an assessment
N
that has the same protection as the Interim Guidance but fails fewer homes.
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1.0 INTRODUCTION
Although the average blood-lead concentration of children has dropped dramatically over
the last twenty years, there are still an estimated 930,000 children aged 1-5 years with blood-lead
concentrations greater than or equal to 10 ug/dL [9]. Lead in dust, soil, and paint in children^
residences is considered the primary source of lead exposure for these children. The Residential
Lead Based Paint Hazard Reduction Act of 1992 (Title X) amended the Toxic Substances
Control Act (TSCA) by adding Title IV, "Lead Exposure Reduction." Section 403 of TSCA *
required EPA to promulgate regulations that identify lead based paint hazards, lead contaminated
dust, and lead-contaminated soil [4]. Section 402 ofTSCA required EPA to finalize a federal
regulation "to ensure the availability of a trained and qualified workforce to identify and address
lead-based paint hazards, and to protect the general public from exposure to lead hazards" [5]. In
addition, the rule was established "to ensure that individuals and firms conducting lead-based
paint activities in target housing and child-occupied facilities will do so in a way that safeguards
the environment and protects the health of building occupants, especially children aged 6 years
and under" [5].
In September, 1995, while EPA was in the process of developing the Section 403
•
regulation (rule), EPA issued a notice which contained "information designed to serve as
guidance [Interim Guidance] until the promulgation/of the final rule" [4]. This information
j
contained media and component standards by which those addressing lead-based paint concerns
could conduct their activities. In particular the Interim Guidance provided standards for
sampling floor dust, window sill dust, window well dust, soil, and paint samples.
In August, 1996, EPA issued a final rule for the Section 402 regulation that required a
i
risk assessment, lead hazard screen, inspection, and risk assessment/inspection be performed by a
certified risk assessor. The Section 402 rule did not dictate one set o£methodologies or
/
standards for carrying out the activities, but listed documents that had appropriate
methodologies/standards that could be used for conducting the activities [5]:
• U.S. Department of Housing and Urban Development (HUD) Guidelines for the
Evaluation and Control of Lead-Based Paint Hazards in Housing [HUD Guidelines];
• EPA Guidance on Residential Lead-Based Paint, LeadJ-Contaminated Dust, and Lead-
Contaminated Soil [403 Interim Guidance];
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• EPA Residential Sampling for Lead: Protocols for Dust and Soil Sampling;
Regulations, guidance, methods or protocols issued by States and Indian Tribes that
have been authorized by EPA;
• Other equivalent methods and guidelines.
Section 402 provides general guidance for conducting risk assessment activities and
references the HUD Guidelines and the Section 403 Interim Guidance as providing more
specifics on conducting risk assessment activities. The HUD Guidelines provide specific
methodologies on how to conduct the risk assessment activities and provide standards against
which the media samples collected are to be compared. The 403 Interim Guidance provides
some detail on how to conduct the risk assessment activities and also provides standards against
which the media samples collected are to be compared. Differences and distinctions between
Section 402, the HUD Guidelines, and the Section 403 Interim Guidance are as follows:
1. Section 402 does not make a distinction between window well and window sill
sampling for a lead hazard screen. Section 402 just requires that dust samples be
collected from "windows". The HUD Guidelines make a distinction between
sampling from window wells and window sills, and both the HUD Guidelines and the
Section 403 Interim Guidance provide individual standards for the window sills and
the window wells.
2. For both a risk assessment and lead hazard screen, Section 402 does not make a
distinction between sampling dust from carpeted and uncarpeted floors. Section 402
just requires that dust samples be collected from "floors". The HUD Guidelines make
a distinction between sampling from carpeted and uncarpeted floors and provides
standards for both types of floors. The Section 403 Interim Guidance recommends
that floor dust sampling occur on uncarpeted floors and only provides a standard for
uncarpeted floors.
In June 1998, EPA issued a Proposed Rule for Section 403 [20]. The Proposed Rule
differs from the 403 Interim Guidance in the following ways:
1. While the Interim Guidance did not make any distinction between carpeted and
uncarpeted floors, the Proposed Rule provides a standard for uncarpeted floors but
states that EPA has not made a decision on a standard for carpeted floors,
2. The Proposed Rule halves the uncarpeted floor and window sill standards listed in the
Interim Guidance and does not provide a standard for window wells,
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3. The soil standard was decreased from 5,000 ppm in the Interim Guidance to 2,000
ppm in the Proposed Rule, and
4. The arithmetic average from uncarpeted floor dust-lead loading, window sill dust-lead
loading, and dripline and mid-yard soil-lead concentration was compared to the
corresponding standard in the Proposed Rule, whereas each individual sample result
was compared to the relevant standard in the Interim Guidance.
The purpose of this task is to characterize the probability that a certified risk assessor
correctly identifies a lead-based paint hazard in single family housing units when using various
options allowed by the protocols specified in Section 402 regulations and when using the
standards and methods prescribed in both the 403 Interim Guidance and Section 403 Proposed
Rule. Table 1-1 lists the standards.
Table 1-1. Environmental Standards Used in the Analyses.
Media
Dust Wipe
Soil (Bare)
Floors
Window Sills
Window Troughs
Painted components with areas
of deteriorated lead-based
paint'"
Hazard Standards for Comparison
EPA Interim 403 Guidance
2 lOOpg/ff
i500^g/fta
2800//g/ft2
2 5,000 ppm
Any deterioration present
EPA Proposed 403 Rule
2 50//g/ft"
2 250//g/ft2
None
2 2,000 ppm
1) 22ft2 deteriorated for large interior
components; 2) 2 1 0 ft2 deteriorated
for large exterior components; or 3)
2 10% of the surface deteriorated for
small components
* Floor dust wipe samples from uncarpeted floors only.
** The statutory definition of lead-based paint is paint with 2 1.0 mg/cm2 lead or 20.5% lead by weight.
In particular, the probability of correctly identifying a lead-based paint hazard was
evaluated both from the perspective of a health hazard as characterized by a resident child with
blood lead concentration greater than or equal to 10 ug/dL, and from the perspective of
environmental lead levels being above a given standard/ The choice of sampling options
included the number of rooms, the location of samples to be collected, and whether to conduct a
lead hazard screen or a full risk assessment. In addition, the type of estimator used to
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February 15. 1999 3
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characterize the lead hazard in a home (arithmetic mean, geometric mean, and the maximum
value across samples within a home) was assessed.
Although a certified risk assessor may perform several activities, the focus of the analysis
was on the risk assessment and the lead hazard screen.
The costs for each of the activities were solicited from several contractors around the
country and were provided for descriptive purposes only.
Comparisons involving the Interim Guidance and the Proposed Rule followed their
respective protocols with one exception. For both sets of protocols, data for carpeted floors were
also included in the analysis. Neither the Interim Guidance nor the Proposed Rule provide a
standard for carpeted floors; in fact, the Proposed Rule explicitly states that a standard for
carpeted floors was not included. Including data for carpeted floors in the analysis was provided
to assess sampling that may be conducted under the HUD Guidelines.
1.1 OBJECTIVES
The overall objectives of the analyses discussed in this report are to evaluate some of the
choices a risk assessor may make when performing a lead hazard identification at a single family
home, and to evaluate the differences between the 403 Proposed Rule and the 403 Interim
Guidance. This includes the assessment of 1) the sampling choices a risk assessor may make
during a risk assessment and 2) the choice between performing a risk assessment or a lead hazard
screen.
The statistical analysis objectives in this study are the following:
1. Characterize how different sampling protocols affect a) the probability of correctly
identifying a health hazard (defined for purposes of this analysis as the presence of a
child with a blood-lead concentration greater than or equal to 10 ug/dL) in single
family housing (performance characteristic analysis) and b) the cost of the
assessment fcost analysis). Also characterize differences between the 403 Interim
Guidance and the 403 Proposed Rule in the probability of correctly identifying a
health hazard in single family housing (performance characteristic analysis).
2. Characterize for a risk assessment and lead hazard screen a) how well different
estimators and sampling protocols estimate the true average lead levels in a single
family home, and b) the error probabilities associated with concluding that a home is
above or below a given media standard for different estimators and sampling
protocols (error probabilities analysis').
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3. Assess which sampling locations a risk assessor may want to target in order to best
evaluate the potential lead hazard to a child (pathways analysis').
Performance characteristics (sensitivity, specificity, negative predictive value, and
positive predictive value), their associated 95% confidence intervals, and cost data obtained from
risk assessors around the country were used to assess Objective 1. Within-home variance
estimates and probability estimates of 1) incorrectly failing a home when the true lead level in a
home was below a media standard (Type I error or false positive) and 2) incorrectly passing a
home when the true media lead level in the home was assumed to be above the media standard
(Type n error or false negative) were used to assess Objective 2. Correlation and structural
equation modeling (pathways modeling) were used to assess Objective 3.
1.2 STRUCTURE OF THE REPORT
Data from the Rochester Lead-in-Dust study were used for all analyses in this report.
Cost information collected from risk assessors around the country was also used in the Objective
1 analysis, while data from the Comprehensive Abatement Performance (CAP) Study and the
Rhode Island Department of Health were also used in the Objective 2 analyses. Section 2
presents the conclusions drawn from the three sets of analyses. Section 3 presents quality
assurance information for the data used in this analysis. Background information specific to the
Rochester Lead-in-Dust study data, the Rhode Island Department of Health data, and the Risk
Assessor Cost Survey is provided in Section 4. The data and statistical methodology used in the
analyses is discussed in Section 5. Results are presented in Section 6. A discussion of the results
and conclusions is provided in Section 7, and references are provided in Section 8. Supporting
documents and information are presented in the appendices.
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2.0 CONCLUSIONS
This section presents overall conclusions drawn from analyses using the Rochester Lead-
in-Dust study data, the Comprehensive Abatement Performance Study data, data from the Rhode
Island Department of Health, and cost information collected from nine risk assessors around the
United States.
2.1 OBJECTIVE 1; PROBABILITY OF CORRECTLY IDENTIFYING A LEAD-BASED PAINT
HEALTH HAZARD IN SINGLE FAMILY HOUSING AND THE COSTS ASSOCIATED
WITH THE RISK ASSESSMENT
2.1.1 Risk Assessor Costs
Caution: The results and conclusions presented below were based on responses from nine
contractors in phone interviews conducted in May, 1997, and follow-up interviews
conducted in April, 1998 with seven of the original nine contractors. ^Because of the
small sample size and changing markets for risk assessments and sample analyses,
caution should be exercised when interpreting these results.
• The estimated cost of a risk assessment in areas where they are most commonly
performed was $435, while the average cost for a lead hazard screen was $169.
• There was tremendous variability among contractors in the total estimated costs for
risk assessments, inspections, lead hazard screens, and risk assessments/inspections.
Total costs ranged from $90 for a lead hazard screen by a contractor in the Northeast
to $2,825 for a risk assessment/inspection by a contractor in the South. Some
possible reasons for the differences may include the demand for the service or the
number of contractors in the area. One contractor in the South thought his prices
were higher because he performed fewer risk assessment activities in his area of the
country than may be performed in other areas of the country.
• Generally the cost per sample included both the collection and analysis costs, though
some contractors did charge analysis fees separately and included the collection cost
in the base fee.
• The average total cost per sample (collection plus analysis costs) was highest for
composite dust samples ($20) and lowest for water samples ($13).
• 'A"verage\the total cost per composite dust sample ($20) was only slightly higher than
the average total cost per single dust sample ($19). (Note that the number of samples
in the composite was not reported, and only three contractors reported costs for the
composite dust sample compared to nine for the single dust samples.)
• Paint chip total costs per sample were not reported, even for those contractors that
utilized paint chip samples in their assessments. For those assessors that performed
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paint chip analysis, the costs for the sampling tended to be included in the base fee
for the environmental sampling.
• The average number of samples collected during an activity depended i
contractor as well as the media sampled.
2.1.2 Performance Characteristic Analysis
Using only the Rochester Study data, four performance characteristics were used in this
analysis to assess various sampling protocols and standards. The four characteristics used in this
analysis are sensitivity, specificity, positive predictive value (PPV), and negative predictive value
(NPV). Briefly,
a) Sensitivity is the probability a home fails an assessment given that there is a child
with an elevated blood-lead concentration in the home,
b) Specificity is the probability a home passes the assessment given that there is a child
with a low blood-lead concentration in the home,
c) PPV is the probability the child in the home has an elevated blood-lead concentration
given that the home failed the assessment, and
d) NPV is the probability that the child in the home has a low blood-lead concentration
given that the home passes the assessment.
For all four characteristics, a higher probability reflects a more accurate assessment. The
following are the conclusions drawn from the results of the performance characteristic analysis:
• Application of the 403 Proposed Rule failed fewer homes than the 403 Interim
Guidance standards without sacrificing the ability to determine whether a health
hazard exists. The NPV, specificity, and PPV were higher for the 403 Proposed Rule
standards than for the 403 Interim Guidance standards, while the sensitivity was the
same for both sets of standards. This occurs despite the exclusion of a window well
dust standard in the Proposed Rule.
• The Proposed Rule use of the arithmetic mean of the dust and soil samples combined
with the lower media standards provides a slightly more discriminating assessment,
than the Interim Guidance which uses the maximum value of the dust and soil
samples to compare to higher media standards. The sensitivity and NPV for a risk
assessment under the Proposed Rule is 91.7% and 92.6%, respectively, and 91.7%
and 87.5% under the Interim Guidance.
• In the assessment of the number of rooms from which to collect dust samples during
a risk assessment, collecting dust wipe samples from four rooms (i.e., the bedroom,
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play area, interior entryway, and kitchen) did not significantly improve the
performance characteristics when compared to fljfe collecting dust wipe samples from
only two rooms (i.e., the bedroom and play area). Table 2-1 presents the
performance characteristics when dust samples are collected from two and four
rooms and the Interim Guidance and Proposed Rule standards are applied.
Table 2-1. Summary of the Performance Characteristics when Dust Samples
are Obtained from Four Rooms and Two Rooms in a Home.
Performance
Characteristic
Sensitivity
Specificity
PPV
NPV
Four Rooms
(Bedroom, Play Area, Entryway,
Kitchen)
Interim
Guidance
88.2%
19.7%
22.1%
86.7%
Proposed
Rule
64.7%
74.2%
39.3%
89.1%
Two Rooms
(Bedroom and Play Area)
Interim
Guidance
88.2%
21.2%
22.4%
87.5%
Proposed
Rule
58.8%
77.3%
40.0%
87.9%
Within the respective guidance standards, the differences between the performance
characteristics shown in Table 2-1 were not statistically significant.
• In terms of sensitivity and NPV, under the Interim Guidance standards, using the
maximum value to characterize the house dust and soil lead levels did a slightly
better job of detecting a lead health hazard when compared to using either the
arithmetic or geometric mean. Under the Proposed Rule standards, the arithmetic
mean does a slightly better job of detecting a lead health hazard when compared to
the geometric mean or maximum value.
• There was no quantitative difference in identifying lead health hazards through a risk
assessment using paint samples from surfaces with greater than 15% deteriorated
paint as opposed to using paint samples from surfaces with greater than 5%
deteriorated paint. The performance characteristics were not statistically different.
• Under the Interim Guidance, a lead hazard screen that samples only window sills or
only window $rells/for the window sampling is less effective (in terms of sensitivity
and NPV) hi identifying potential health hazards than the full risk assessment. When
both the window sill and window wells are sampled, the hazard screen (sensitivity =
91.7% and NPV - 89.5%) was as effective as the risk assessment (sensitivity =
91.7% and NPV = 87.5%). Under the Proposed Rule, when the window sills are
sampled, the lead hazard screen is as effective as the full risk assessment, sensitivity
was 91.7% and 91.7% and the NPV was 91.7% and 92.6%, respectively. When no
windows are sampled, the Proposed Rule lead hazard screen is not as effective. Note
that the results may be difficult to interpret since the Rochester study homes would
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February 15, 1999 8
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generally have not met the criteria for choosing a lead hazard screen over a risk
assessment (i.e., 95% of all the homes were built before 1970).
2.2 OBJECTIVE 2: ASSESSMENT OF ESTIMATORS OF "TRUE" AVERAGE LEAD
LEVELS AND SAMPLING PROTOCOLS USING ERROR PROBABILITIES
Data from the Rochester Study, CAP Study, and the Rhode Island Department of Health
were used to calculate within-house components of variation for two types of error probabilities:,.
Type I error and Type n error. Briefly,
a) Type I (False Positive) error is the probability that a home fails the assessment given
that the home should have passed the assessment and
b) Type II (False Negative) error is the probability that a home passes the assessment
given that the home should have failed the assessment.
The error probabilities were calculated for three statistics: geometric mean, arithmetic
mean, and maximum value. Each statistic's ability to characterize the "true" lead levels in a
house were assessed individually for different sampling protocols, different media (dust and
soil), different sampling components (floors, window sills, and window wells), and different
standards (Interim Guidance and Proposed Rule).
The within-house variability estimates that were used to calculate error probabilities were
from the Rochester study floor, window sill, and window well dust wipe samples; the CAP study
foundation and boundary soil samples; and the Rhode Island Department of Health floor,
window sill, and window well dust wipe samples, and side of house/foundations'soil samples.
The following general conclusions are drawn from the error probability analysis for each set of
data.
• The maximum value has the highestType I (false positive) and lowest Type H (false
negative) error rates for each medj^Jthe geometric has the lowest Type I and highest
Type H error rates, and the arithmetic mean Type I and Type H error rates always lie
between the maximum value and geometric mean error rates.
• Both Type I and Type II errorrates were high (usually over 25%) for all three
statistics when the true medi^fead level was assumed to be within 20% of the media^)
standard. The high error rates in a fairly large window imply that there is a very
large "gray" area around the standard where there is a high probability of a "wrong"
decision.
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• The Type II error probabilities decrease as the number of samples collected for dust
and soil increases from two to four samples, when the maximum value is used. The
Type n error probabilities are less dependent on the number of samples collected
when the arithmetic mean and geometric mean are used to characterize the dust and
soil. This implies that the level of protection in a risk assessment is dependent on the
number of dust and soil samples collected especially if the maximum value is used to
characterize the dust and soil samples.
• The combination of lowering the dust and soil standards and using the arithmetic
mean as the characterization of floor dust lead, window sill dust lead, and soil lead in
the home, as written in the Proposed Rule, seems to have improved the
discrimination of the risk assessment from how it was under the 403 Interim
Guidance by reducing the Type I and Type II error probabilities.
OBJECTIVE 3: ASSESSMENT OF SAMPLING LOCATIONS RISK ASSESSORS MAY
WANT TO TARGET
A risk assessor has a choice of rooms and components that may be sampled during a risk
assessment. To inform a risk assessor on which rooms and components to sample, this analysis
assessed the rooms and components which significantly impacted the blood-lead concentration of
children in the Rochester Study. Below are the conclusions drawn from this analysis.
• There were statistically significant and positive bivariate correlation between the log-
transformed blood-lead concentration and the log-transformed floor, window sill, and
window well dust wipe lead loadings from the bedroom, play area, and kitchen. This
indicated that the pathways of lead from the floor, window sill, and window well in
^—^ the bedroom, play area, and kitchen to the blood should be assessed in the SEM
analysis^
• The most statistically significant correlation among the log-transformed dust wipe
lead loadings occurred between 1) the kitchen and play area window wells, 2) the
v interior entryway and the kitchen floors, and 3) the play area and bedroom floors.
This indicated that the pathways of lead from the kitchen to play area window wells,
play area to kitchen window wells, interior entryway to kitchen floors, and play area
to bedroom and bedroom to play area floors should be assessed in the SEM analysis.
• The SEM analysis showed the play area floor dust to be the only statistically
significant direct pathway of lead exposure to the child's blood. There were no
statistically significant indirect pathways of lead exposure. This implies the risk
assessor may want to sample dust from the child's play area floors to best assess the
lead hazard available to the child.
• The pathways of lead from the window well to the window sill in the bedroom and
play area were statistically significant. This indicates that sampling both the window
well and window sill may be unnecessary.
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3.0 QUALITY ASSURANCE
Four sources of data were used for the analyses in this report: the Rochester Lead-in-
Dust study data, the Comprehensive Abatement Performance (CAP) Study data, data from the
Rhode Island Department of Health, and data from phone interviews of risk assessors throughout
the United States. The Rochester Study, CAP Study and Rhode Island Department of Health
data were not collected specifically for these analyses. Therefore the quality of the data is
dependent on the data collection methods employed by original data collectors. In contrast, the
risk assessor information was collected specifically for these analyses. Below are brief
descriptions of the data collection methods employed for each source of data to ensure the
integrity of the data for analysis.
The data from the Rochester Study and the CAP Study have already been subjected to
quality assurance checks by the respective study coordinators. For each study, the data analyses
have been presented in peer-reviewed study reports [8,21,22] and several refereed journal
articles [10,11,12]. Each data set was available for this analysis as a SAS® data set. The
accuracy of each data set was verified by calculating summary statistics and comparing the
results to summary tables in the study reports [8,22]. Any differences were noted and resolved.
The Rhode Island Department of Health data were collected by health department
officials as part of the lead prevention program in Providence, Rhode Island. The data were not
collected with the intent of being part of a study and thus did not require the same level of quality
control. Blood and environmental data were received on 3.5" diskettes as ASCII files. The
ASCII files were converted to SAS® data sets. The blood-lead and environmental-lead data were
matched by a unique child identifier, and data summaries were calculated. Results of the
summaries were discussed with a program official. Discrepancies were noted and resolved by
the program official by checking the original records for accuracy. Upon approval from the
program official, changes were made to the SAS0 data sets to reflect the correct information.
Several iterations of performing data validation, talking with the program official, and revising
the SAS® data set produced final versions of the SAS® data sets suitable for statistical analysis.
A data dictionary was created detailing the information in the final SAS® data sets.
Cost information from the risk assessors was collected through use of a questionnaire
executed over the telephone. After the phone interviews were complete, the recorded data were
double entered, into a Microsoft Access® data base (i.e., entered twice into the data base on two
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separate days). During the data entry, data verification was performed. After all data were
entered twice, both sets of data were compared, any discrepancies were resolved, and the final
data base was converted to SAS® using DBMSCOPY®. Additional data verification was
conducted in SAS® by running frequencies and summary statistics. The data in SAS® were also
compared to the hardcopy questionnaires. Through the entire process, any discrepancies were
noted and resolved immediately.
For all sets of data, as the statistical analyses were performed, verifications of the analysis
data were periodically performed using frequency counts and summary statistics. All programs
used to conduct the statistical analysis and to prepare tables and graphs were validated through
visual inspection. When possible, direct processing from SAS® output to WordPerfect tables or
figures was employed to reduce any chances of transcription error.
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4.0 DATA SOURCES
Two types of data were needed for the evaluation of the Section 402 regulations. The
first type centered around pre-intervention child blood-lead data and associated pre-intervention
environmental-lead data. The second type of data consisted of costs associated with performing
the activities recommended in the Section 402 regulations.
Two general sources of environmental-lead and blood-lead data were identified: 1)
formal lead studies with published results, and 2) state and local health departments which have
lead programs that collect environmental and blood information for cases of lead poisoning. The
lead studies that were identified as possible data sources included the
• Comprehensive Abatement Performance Study (CAPS);
• the Baltimore Repair and Maintenance Study (R&M);
• the Three-City Lead Demonstration Projects: the Baltimore Soil-Lead Abatement
Demonstration Project, the Boston Lead-In-Soil/Lead-Free Kids Demonstration
Project, and the Cincinnati Soil-Lead Abatement Demonstration Project;
• the Milwaukee Low-Cost Intervention Study;
• the HUD Abatement Demonstration;
• the HUD National Survey; and
• the Rochester Lead-in-Dust Study.
Health departments across the United States were canvassed for environmental-lead and blood-
lead data. Seven agencies responded by sending data:
• Pinellas County Health Department, St. Petersburg, Florida;
• Nebraska Health and Human Services System, Lincoln, Nebraska;
• Vermont Department of Health, Burlington, Vermont;
• Ohio Department of Health, Columbus, Ohio;
• Rhode Island Department of Health, Providence, Rhode Island;
• Missouri Department of Health, Jefferson City, Missouri, and the
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• Bureau for Public Health, Charleston, West Virginia.
For each source of data, a set of minimum requirements needed to be met for the data to be
included in the analysis. Appendix F provides the criteria used to evaluate the appropriateness of
each data source. Of all the data that were available for evaluation, only data from the Rochester
Lead-in-Dust study and the Rhode Island Department of Health met the criteria.
To obtain cost information associated with Section 402 activities, a phone interview of
risk assessors was performed across the United States. Cost data from nine risk assessment
contractors in nine States were logged for analysis.
This section provides a description of the data and the process by which the data were
collected. Section 4.1 describes the Rochester Lead-in-Dust study, including a description of the
purpose of the study and the data collected in the study. Section 4.2 discusses the Rhode Island
data included in the analysis and the difficulties in locating usable data from non-study
environments. Finally, Section 4.3 provides a brief discussion of the data obtained from the risk
assessors through the cost interview.
4.1 ROCHESTER LEAD-IN-DUST STUDY
The Rochester (NY) Lead-in-Dust Study was designed to address several objectives: "to
determine whether dust-lead loading (fig/ft2) or dust-lead concentration (ug/g) is a better
predictor of children's blood lead levels; to investigate whether dust sampling using vacuum
methods or a wipe method is more predictive of children's blood lead levels; to identify which
interior household surface(s) should routinely be sampled for dust lead measurements; and to
estimate the probability of a child having an elevated blood lead level on the basis of a known
level of lead in house dust, controlling for other potential exposures [8]."
Children 12 to 30 months of age who lived in the city of Rochester and had no known
history of an elevated blood-lead concentration were eligible for the study. In addition to the age
of the child, the location of a child's residence, and the blood-lead history of the child, other
eligibility criteria were applied to control for the possibility of non-residential, non-typical
sources of lead affecting blood-lead concentrations [1,3, 8]. Two hundred and five children
were enrolled into the study. To summarize the homes in the study, Table 4-1 shows the
distribution of the year in which a home was built and the age of the child at blood collection.
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This table shows that 84% of the homes in the study were built prior to 1940 and that all of the
children in the study were between 12 months and 30 months of age.
Collection of questionnaire data, blood-lead samples, and environmental-lead samples
occurred between August and November, 1993. Venous blood samples were obtained by a
certified pediatric phlebotomist during a home visit using lead-free containers provided by the
New York State Department of Health Clinical Laboratory Evaluation Program. Three dust
collection methods were used to sample settled house dust: wipe sampling, Dust Vacuum
Method (DVM) sampling, and Baltimore Repair and Maintenance (BRM) vacuum sampling [8].
Table 4-1. Distribution of the Year Homes were Built and the Age of the Children for the
Rochester Lead-in-Dust Study.
N
Percent of Population
Year in which home was built
Pre-1940
1940- 1969
1970- 1979
Post-1979
172
22
1
10
84%
11%
1%
5%
Age of children at time of blood collection
12-18 months
1 8 - 24 months
24 - 30 months
90
57
58
44%
28%
28%
Dust samples were collected from the window well, interior window sill, and floor in the
child's bedroom; the window well and floor in the kitchen; the window well, interior window sill,
and floor in the child's principal play area; the interior window sill and floor in the living room;
the interior entryway floor; and the exterior porch floor. Dust samples from carpeted and
uncarpeted floors were collected over a 1 ft2 area. Dust samples from window wells and interior
window sills were collected over one-third of the available surface area. Soil core samples, taken
at a depth of '/z inch, were collected in two distinct areas: the perimeter of the foundation and the
child's principal outside play area. There were a significant number of homes for which play area
soil was not collected. Three core soil samples were taken on each side of the house around the
perimeter of the foundation where bare soil was present and combined for a composite
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foundation sample (in general there were 12 core samples). The soil samples were separated into
fine and coarse samples for laboratory analysis. Two water samples were taken at each home.
One sample was a first draw after an 8-hour stagnation period. The other was collected after a
one minute flush. Three XRF paint-lead measurements were taken from areas such as the
window well, sill, and sash; the floor, and the door in the kitchen; the child's bedroom; the
principal play area; the entryway; the living room; and any deteriorated surface. The three XRF
measurements on each surface were averaged. Laboratory paint chip analysis (atomic absorption
or inductively-coupled plasma emission spectroscopy) was used only when XRF could not be
used due to an inaccessible surface, an ornate or severely-curved surface, or when the painted
surface was too small to measure. XRF readings were not substrate corrected or confirmed by
laboratory analysis for this study [8]. Only XRF paint-lead measurements were discussed in this
report. A visual inspection of each surface was also performed, and the paint condition was rated
as poor, fair or good.
For the analysis, soil-lead concentrations were estimated by calculating an arithmetic
average of lead concentrations in fine and coarse soil fractions.
4.2 HEALTH DEPARTMENT DATA SOURCES
Additional sources of data were sought to compliment and contrast the information found
in the environmental lead studies. To find these additional sources, staff at the Centers for
Disease Control and Prevention (CDC) provided a list of forty health departments in the U.S.
currently participating in CDC's Childhood Lead Poisoning Prevention Grant Program. A brief
questionnaire was developed to collect information from these departments on the population
size of the database, agencies funding the program, the availability of the data, the age of
children in the program, whether blood and/or environmental (soil, dust, paint, and water)
samples were obtained, and the format of the data.
Following this first survey, a list of twenty-four health departments with potentially
useful data was developed. A more detailed questionnaire, "Data Set Assessment", was
developed requesting information from these departments about the data. A copy of this second
questionnaire is included as Example K-l in Appendix K. Included in this second questionnaire
were questions concerning the format of the data, specific information about blood sampling of
children, specific information about environmental sampling, and whether a unique identifier
Draft Report - Do Not Quote, Cite, Copy or Distribute February 15, 1999 16
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was available to link the environmental data and the blood data. A second telephone interview
was conducted.
As a follow-up to the phone call, a letter was sent to the twenty-four health departments
requesting their participation in the data collection effort for EPA and explaining how the data
would be used in this study. (A copy of the letter and information sent to each agency is
provided as Example K-2 of Appendix K). Follow-up calls were made three weeks later. As a
result of this effort, data were obtained from health department agencies in Columbus, Ohio;
Providence, Rhode Island; Omaha, Nebraska; St. Petersburg, Florida; Burlington, Vermont;
Charleston, West Virginia; and Jefferson City, Missouri. These data were entered into SAS®
data sets and were evaluated as to its applicability according to the criteria listed in Appendix F.
Table K-l of Appendix K provides a summary of the data collected from each health department.
The last column in the table gives a brief description of the advantages and disadvantages of
using the data sources. Only the data provided by the Rhode Island Department of Health met
the necessary requirements for analysis.
Rhode Island Department of Health Data
As part of their on-going lead program, The Rhode Island Department of Health has
logged the occurrences of elevated blood-leads. When necessary, the health department
requested that environmental sampling occur and has logged that information. Though the
Rhode Island Department of Health has been collecting blood and environmental information for
several years, only data collected in 1995 and 1996 contributed to this analysis. Limiting to two
years worth of data was necessary to ensure that the data could be reviewed and corrected, as
necessary, in time to be included in the analysis.
As shown in Table K-l of Appendix K, blood, dust, soil, paint, and water samples were
collected and recorded. Two-hundred and eighty-five children aged 6 months to 9 years and 4
months had blood samples available for analysis, and between 129 and 325 homes had the
appropriate environmental samples needed for the analysis. Table 4-2 provides the distribution
of children's ages. Eighty-five percent of the children were between 6 months and 48 months at
the time of blood sampling. The location of the blood sampling was not available. There were a
number of homes in which one or more children had results for multiple blood samples logged.
For homes in which multiple children were sampled, only the youngest child in the home was
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included in the analysis. Generally, a fingerstick blood sample was obtained for comparison
against the action level of 25 ug/dL. (Note, at the time the data were obtained for the analysis,
the action level for blood lead was moving towards 20 ng/dL, but 25 ug/dL was the standard for
comparison at the time of sampling.) If the fingerstick blood lead concentration was greater than
25 ug/dL, then generally a venous sample was obtained for confirmation, generating a second
blood sample for the child. When a venous blood sample result was available, this was used in
the analysis, otherwise the fingerstick blood sample result was included.
Table 4-2. Distribution of the Age of the Children in the Rhode Island Department of Health
Data.
Aqe of the children at the time of blood collection
6-18 months
1 8 - 24 months
24 - 36 months
36 - 48 months
48 - 60 months
60-72 months
72 — 1 1 2 months
N
47
61
73
61
23
12
8
Percent of Population
16.5%
21.4%
25.6%
21.4%
8.1%
4.2%
2.8%
Environmental samples were collected by a contractor for the Health Department to
locate the lead problems in the child's environment. Dust wipe and vacuum samples were taken
in 129 homes from a 1, ft2 area on carpeted and uncarpeted floors, window wells, and window
sills in the bedroom, dining room, hallway, kitchen, living room, and play room. Of the 129
homes, 109 homes had dust wipe samples taken. Seven hundred and sixty-six soil samples were
taken from 264 homes from the top 2 centimeters of soil from the side of the home at the
foundation. Paint chips of at least 2 in2 in size were collected from the interior and exterior of
the home including doors, trim, baseboards, ceilings, casings, walls, jambs, sills, wells, and
{*=• — r—
furniture for 265>homes. The condition of the painted surface was not reported. \Note thatjno
information about the type of housing or age of housing the children lived in was available for
this analysis.
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When the data were subset to include all the information needed for the Objective 1 and 3
analyses, it was found that only 73 homes could be included in the analysis, with these homes
having only between 1 and 10 samples per home. Note that 95% of the homes had a total of 5 or
fewer dust samples collected.
Caution should be exercised when viewing the results obtained from the Rhode Island
Department of Health data. These data were not collected under a controlled setting as were the
Rochester study data. In the Rhode Island data, an elevated blood lead concentration motivates
the collection of environmental samples, not a statistical study design. As a result, the Rhode
Island data generally represent children with blood lead concentrations ranging from 1 ug/dL"to
104 ug/dL with 90% of the children having blood-lead concentration of 20 ug/dL or greater:
This is a different population from the one assessed using the Rochester study data, where the
blood lead concentrations ranged from 1.4 ug/dL to 31.7 ug/dL. In addition, background
information such as type of housing, length of time at the residence, pica habits, etc. are not
available. One advantage to the Rhode Island dataset is that it does reflect the environmental
sampling choices a risk assessor makes as opposed to the designed sampling scheme found in the
Rochester study data.
As illustrated with the lead study and health department data, obtaining enough data from
secondary sources to meet the requirements for analysis is difficult. Because of the varying
study designs in the lead studies and the lack of a standard format used among the health
departments, only the Rochester Study and Rhode Island data met the necessary requirements.
4.3 RISK ASSESSOR COST INFORMATION
Data on risk assessment and lead hazard screen costs were collected through an interview
of certified risk assessors in the United States. To identify certified risk assessors, the
Governor's Legislative Conference supplied a list of states throughout the country with
certification programs in lead risk assessment. From this list, several states were contacted to
obtain lists of individuals who had been through the certification process and were actively
involved in conducting lead risk assessments. A questionnaire was developed to be used in a
telephone interview to obtain cost information for lead risk assessment, hazard screen,
inspection, and risk assessment/inspection. This cost questionnaire was pilot-tested in a
telephone interview of six risk assessment contractors in Columbus, Ohio. The data were
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compiled from the pilot, and modifications to the questionnaire were made based upon the initial
interviews. The final cost questionnaire was administered by telephone to nine contractors in
different parts of the United States: the northeast, south, and west. Note that the contractors
were not randomly selected. The interviewer began at the top of the calling list and proceeded
down until a successful interview was obtained. Eleven contractors were contacted, and no
contractor refused to be interviewed. The two contractors that did not provide information were
willing to participate but were too busy at the time of the call to provide information.
The interviewer asked about the costs associated with four activities that a risk assessor
can perform: a risk assessment, lead hazard screen, inspection, and risk assessment/inspection.
Within each of these activities, the respondent was asked whether a basic fee was charged for the
activity or whether separate fees were charged for specific components of the activity. For
instance, within a risk assessment, separate fees could be charged for the visual assessment, the
environmental sampling, or the risk assessment report. In addition, detailed questions on the
particulars of the environmental sampling were asked. The questions included:
• What are the collection costs, analysis costs, and total costs per dust, soil, and paint
samples?
• How many of these samples are typically collected?
All this information was recorded on a questionnaire. Appendix C contains a copy of the actual
questionnaire used in the telephone interview and provides a summary of each of the responses.
As seen in Appendix C, not all the questions were answered by the contractors. About one year
after the initial phone call, in April 1998, a follow-up phone call was made to each contractor to
obtain updated information.
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5.0 STATISTICAL METHODS
The methods used in the data analysis and preparation of the data are discussed in this
section. To characterize the probability of a certified risk assessor correctly identifying a lead-
based paint hazard, three statistical objectives were defined. They are
1. Characterize how different sampling protocols affect a) the probability of correctly
identifying a health hazard (defined for purposes of this analysis as the presence of a
child with a blood-lead concentration greater than or equal to 10 ug/dL) in single
family housing (performance characteristic analysis) and b) the cost of the
assessment (cost analysis). Also characterize differences between the 403 Interim
Guidance and the 403 Proposed Rule in the probability of correctly identifying a
health hazard in single family housing (performance characteristic analysis).
2. Characterize for a risk assessment and lead hazard screen a) how well different
estimators and sampling protocols estimate the true average lead levels in a single
family home, and b) the error probabilities associated with concluding that a home is
above or below a given media standard for different estimators and sampling
protocols (error probabilities analysis). '
3. Assess which sampling locations a risk assessor may want to target in order to best
evaluate the potential lead hazard to a child (pathways analysis).
The methods used to address the first statistical analysis objective included the
calculation of four measurements (performance characteristics): sensitivity, specificity, positive
predictive value (PPV), and negative predictive value (NPV). These measurements were used to
characterize the performance of a lead hazard screen and several specific risk assessment
protocols in terms of how well each protocol was able to identify a home with a child with a
blood-lead concentration greater than or equal to 10 ug/dL. Confidence intervals about the
individual performance characteristics were calculated. The cost estimates obtained via
telephone interview from risk assessors across the country were summarized and used to
calculate estimated costs for each of the risk assessment protocols and the lead hazard screen for
which performance characteristics were calculated.
The second statistical analysis objective utilized variability estimates and distributional
assumptions to estimate error probabilities associated with concluding that the true average lead
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level in a home is above or below a standard. Correlation and pathways analyses were used to
evaluate the third statistical objective.
Section 5.1 discusses the Objective 1 analysis of cost information obtained from risk
assessors around the country and the Objective 1 and 2 performance characteristics. The
Objective 2 error probability calculations are detailed in Section 5.2, and Section 5.3 provides
details on the Objective 3 correlation and pathways analyses.
Note, at the current time, Section 402 does not dictate one set of methodologies for
carrying out activities outlined under Section 402, but lists documents that have appropriate
methodologies. There are two documents which contain the prevalent methodologies: the HUD
Guidelines and the 403 Interim Guidance documents. These documents list nearly the same
methodologies with only a few differences. In addition, in June, 1998, EPA issued its 403
Proposed Rule which differs on several points from the 403 Interim Guidance. Both sets of
differences, as well as the list of documents, are discussed in Section 1.
Throughout the analyses in this report, the Interim Guidance and the Proposed Rule
standards listed in Table 1-1 will be used for comparisons. One exception to the comparisons
using the both the Interim Guidance and Proposed Rule standards is related to the use of samples
from carpeted floors. Carpeted floor samples were included in the application of the Interim
Guidance and Proposed Rule to assess sampling that may be conducted under the HUD
Guidelines. Note that the Section 403 Interim Guidance is recommended as a Section 402
guidance document at this time. When the Section 403 Proposed Rule becomes final, the
guidance in the Proposed Rule will supersede the Interim Guidance as it applies to Section 402.
5.1 OBJECTIVE 1: PROBABILITY OF CORRECTLY IDENTIFYING A LEAD-BASED PAINT
HEALTH HAZARD IN SINGLE FAMILY HOUSING AND THE COSTS ASSOCIATED
WITH THE RISK ASSESSMENT
5.1.1 Risk Assessor Cost Information
Bar charts, pie charts, and tables will be used to present, in Section 6, the summary
statistics calculated for the risk assessor cost information. Appendix C contains a copy of the
questionnaire used to gather the cost information; details of how the risk assessor interviews
were conducted are discussed in Section 4.3. As discussed in Section 4.3, nine contractors in
nine different States were contacted and interviewed in May 1997. The sample of contractors
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was not a statistically representative sample. The information obtained from these contractors,
though, did provide an indication of the costs that are associated with the activities of a risk
assessor. Due to the voluntary nature of the interview, some respondents did not answer all the
questions posed. Follow-up calls were made in April, 1998 to try and fill in the information
gaps. The follow-up calls yielded some additional information, but not enough to warrant
producing summaries for the follow-up calls only. Therefore, all the summaries presented are
only for the May, 1997 calls, with additional discussion of the information gathered from the
April, 1998 interviews provided appropriately.
In order to summarize the data, several questions in the questionnaire were combined.
Below is a discussion of how the answers for several questions were combined to estimate costs
per environmental sample, number of environmental samples collected, and costs for risk
assessments and lead hazard screens as well as a discussion of the naming scheme used to
provide confidentiality for the contractors.
5.1.1.1 Naming Convention for the Contractors
There were nine contractors from across the country which provided risk assessor cost
information. To preserve confidentiality, the contractors were categorized into three regions of
the country, and within each category, randomly assigned an ID number. The three regions were
the northeast (NE), south (S), and west (W). Four contractors were in the northeast region, three
contractors in the south region, and two contractors in the west region. Within each region, the
ID'S were assigned as NE-1, NE-2, NE-3, and NE-4 for the northeast, S-l, S-2, and S-3 for the
south, and W-l and W-2 for the west.
5.1.1.2 Risk Assessment. Lead Hazard Screen. Inspection, and Risk
Assessment/inspection Costs
There were two ways by which contractors allocated costs for an activity:
a) a basic fee for the whole activity
b) separate fees for each component of the activity.
When a basic fee was charged for the activity, the contractor generally fixed a maximum number
of samples that could be collected for the fee. If additional environmental sampling was
required, then the contractor charged additional fees. Some contractors opted to charge separate
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fees for each component of the activity performed: a visual assessment, typical environmental
sampling, and a report. The contractor set a fee for the visual assessment, environmental
sampling, and report and fixed the maximum number of samples to be collected during the
environmental sampling. Similar to the basic fee structure, if additional environmental samples
above those covered in the typical environmental sampling were needed, then additional fees
were charged on a per sample basis. The basic fee structure and separate fee structure were both
used to estimate the costs of the risk assessments and lead hazard screens evaluated during the
performance characteristic analysis.
5.1.1.3 Costs Per Environmental Sample
The average total cost per sample was calculated based on the information in questions
B8, B9, B13, and B15 for a risk assessment, C8, C9, C13, and CIS for a lead hazard screen, D8,
D9, D13, and D15 for an inspection, and E9, E10, E14, and E16 for a risk assessment/inspection
(see Appendix C). The collection and analysis costs per sample were reported, and the total cost
per sample was the sum of these two responses. If either response was not available, then the
total cost was either the collection cost or the analysis cost, whichever was reported. Note that
some contractors reported range of costs for the collection or analysis costs, rather than a specific
cost. In cases such as this, the lowest cost in the range was assigned to a minimum cost variable,
the highest cost in the range was assigned to a maximum cost variable, and the midpoint of the
reported cost range was recorded in the average cost variable. When only an average cost was
reported, the minimum, average, and maximum variables were set equal to the reported average
cost. To calculate the minimum, mean, and maximum collection, analysis, and total costs per
sample, the minimum of the minimum cost variable was equal to the minimum cost, the mean of
the average cost variable was equal to the average cost, and the maximum of the maximum cost
variable was equal to the maximum cost. This allowed all reported information to be utilized.
5.1.1.4 Number of Environmental Samples Collected
The responses to questions B6, B9 and B13, C6, C9 and C13, D6, D9 and D13, and E7,
E10 and E14 were used to estimate the average number of environmental samples collected for a
risk assessment, lead hazard screen, inspection, and risk assessment/inspection, respectively.
When ranges were reported for the number of samples collected, the same strategy as discussed
for the cost per sample was employed.
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5.1.2 Performance Characteristics
Four measurements (performance characteristics): sensitivity, specificity, positive
predictive value (PPV), and negative predictive value (NPV), were used to characterize the
performance of the risk assessment protocols and to assess how well each protocol identified a
lead-based paint health hazard. Each of the performance characteristics is defined in Table 5-1
below.
Table 5-1. Definitions of Performance Characteristics
Media Standard
Target
Blood Lead
Concentration
10//g/dL
< 10//g/dL
Below «) Media
Standard
a
Above k) Media
Standard
In the above table, the letter 'a' represents the number of children which have a blood lead concentration
above a given target and the media lead level (soil-lead concentration, etc.) below the selected standard.
Letters 'b1, 'c', and 'd' represent similar counts. From these counts the following performance
characteristics are calculated
Performance
Characteristic
Definition
Calculation
Sensitivity
(or True Positive Rate)
Probability that a unit fails a risk assessment given
that there is a resident child with an elevated blood
concentration.
b/(a + b)
Specificity
(or True Negative Rate)
Probability that a unit passes a risk assessment
given that a resident child has a low blood lead
concentration.
c/(c + d)
Positive Predictive Value
(PPV)
Probability of a resident child having an elevated
blood lead concentration given that the unit failed
the risk assessment.
b/(b+d)
Negative Predictive
Value (NPV)
Probability of a resident child having a low blood
lead concentration given that the unit passed the
risk assessment.
c/(a+c)
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February 15, 1999 25
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5.1.2.1 Performance Characteristic Calculations
Ideally all four performance characteristics would equal 100%. Figure 5-1 presents an
example of this ideal situation in which a foundation soil standard of 400 ppm is used to
calculate the measures. In reality, achieving 100% for all four performance characteristics is
generally not possible; Figure 5-2 illustrates when 100% is not achieved for positive predictive
value and specificity. Because 100% cannot always be achieved for the performance
characteristics the different risk assessment/lead hazard screen sampling protocols were ^
il,«^4 t-p- ;
evaluated based primarily on sensitivity and NPV measures. The sensitivity focuses in on the
home media failure rate when the child is known to have an elevated blood lead concentration,
while the NPV focuses in on the probability of a child having a low blood lead concentration
when it is known that the media samples have passed the standards.
50-
40-
C3"
1
.2 3O
to
C
o
c:
o
o
•§ z°
§
S
10
n
> * f * •
* ** * ™*
••••V.-." i
. • *
•
*
• • * *
* *
* ** • *
* * * * • *
*
* **
*
• *
* 9
* •
• • "
400 800 1.300 1.600
Dripline Soil-Lead Concentration
2.400
Figure 5-1. Example of an Ideal Situation When 100% is Achieved For All
Four Performance Characteristics.
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February 15, 1999 26
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50
40
J
30-
"3 20
.3
10
400
BOO 1,200 1,600
Dripline Soil — Lead Concentration
2,000
2.40O
Figure 5-2. Example of a Situation Where the Negative Predictive Value and
Sensitivity Equal 100%, but the Positive Predictive Value and
Specificity are Less than 100%.
In addition to calculating the performance characteristic point estimates, confidence
intervals about the different performance characteristics were calculated using an F-distribution
approximation to a binomial proportion [Hollander, 1973]. Using the variables defined in Table
5-1, the confidence limits were calculated as follows:
Lower Confidence Limit: PL (n, B) =
B
B
where
B
Upper Confidence Limit: P°(H, B) = I - P"(n, n - B)
the numerator of the performance measure calculation (i.e., b for sensitivity and
PPV and c for specificity and NPV)
the denominator of the performance measure calculation (i.e., a+b for
sensitivity, c+d for specificity, b+d for PPV, and a+c for NPV)
fy n, n2 the upper yth percentile for the F distribution with r], numerator degrees of
freedom and t|2 denominator degrees of freedom.
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For example, in the case of sensitivity, B is the number of homes that have a child with an
elevated blood-lead concentration and have environmental media samples that are above the
given environmental media standards while n is the number of homes that have a child with an
elevated blood-lead concentration. Note, no adjustment was made to the confidence intervals for
the joint assessment of multiple confidence intervals.
For this analysis, identification of a lead-based paint hazard (i.e., failure or passage of a
unit through a risk assessment or lead hazard screen) and evaluation of the performance
characteristics defined above were based on the evaluation of floor dust, window sill dust,
window well dust, soil, and paint simultaneously.
5.1.2.2 Data Used in the Analysis
As described in Appendix D, there are several different options a risk assessor may make
when collecting dust-lead loading samples. The purpose of this analysis was to assess the impact
these choices may have on the outcome of a risk assessment or lead hazard screen. Several data
sources were examined as to the applicability of assessing any one of these choices (see
Section 4.0). The data sources were required to have collected dust wipe samples, since the
Interim Guidance and Proposed Rule dust standards are provided for dust wipe samples only.
Only the Rochester Lead-in-Dust Study data provided dust wipe sampling and enough additional
information such as room location of the dust samples, individual dust samples from several
locations within a home, and condition of painted surfaces to be included in this analysis.
Specifics of the Rochester Study data are provided in Section 4.1.
In this analysis, the paint standard is assumed to be greater than 10% deteriorated lead-
based paint. In the Rochester Study data, the condition of the paint was reported as good
(between 0 and 5% deteriorated paint), fair (between 5% and 15% deteriorated paint on the
surface), and poor (greater than 15% deteriorated paint on the surface). To best assess the effect
of the assumed paint standard, two sets of analyses were run, where exclusively poor and fair
conditioned surfaces are sampled (> 5% deteriorated paint on the surface) and where poor
conditioned surfaces are sampled (> 15% deteriorated paint on the surface).
The Proposed Rule does not present a standard for carpeted floors. In this analysis,
average carpeted and average uncarpeted floor dust lead loadings are compared separately to the
standard presented for uncarpeted floors.
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In addition, the soil standard in the Proposed Rule is compared to a yard-wide average
soil-lead concentration where the yard-wide average is calculated as the average of the dripline
and mid-yard soil-lead. The Rochester Study data represented foundation and play area soil.
Therefore, for this analysis, the yard-wide average will be calculated as the average of the play
area and foundation soil-lead concentration.
5.1.2.3 Protocols Evaluated
Because of the data limitations, not all choices available to a risk assessor could be
examined. The following are the choices that were evaluated using the Rochester data:
i. Assessment of the number of rooms and types of rooms sampled for dust (shown in
Table 5-2). This assessment addresses the benefits of reducing variability versus
sampling rooms that may contribute little to a child's lead exposure.
ii. Assessment of the effects of using the arithmetic mean dust wipe, a geometric mean
dust wipe, and the maximum dust wipe (shown in Table 5-3).
iii. Assessment of the deteriorated paint condition levels in the HUD Guidelines versus
other options for deteriorated paint condition levels.
iv. Assessment of the choice of conducting a lead hazard screen versus conducting a
full risk assessment (shown in Table 5-4). (Since a lead hazard screen requires the
use of composite samples, simulated composite samples will be used when only
single sample data is available.)
These options were evaluated for each medium individually and for all media standards (i.e.,
dust, soil, and paint) simultaneously.
Note that Section 402 recommends that for a lead hazard screen, composite floor dust,
window dust samples, and samples from deteriorated painted surfaces be compared to their
respective standards. Section 402 does not make a distinction as to the types of floors or the
window components that should be sampled. The 1995 HUD Guidelines present a methodology
for the lead hazard screen that collects floor samples from both uncarpeted floors and carpeted
floors, composites them separately into an uncarpeted floor sample and a carpeted floor sample,
and then compares them to their own standards. In addition, the HUD Guidelines recommend
sampling the window well for the lead hazard screen not the window sills. The Section 403
Interim Guidelines and Proposed Rule do not provide a methodology for sampling from a
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specific component. For windows, the HUD Guidelines and the Interim Guidance provide
hazard standards for both the window well and window sill while the Proposed rule only
provides a standard for window wells. In the HUD Guidelines, standards for both carpeted and
uncarpeted floors are given while the Interim Guidance and Proposed Rule only provide a floor
standard for uncarpeted floors. The different interpretations and standards allow several
scenarios under which the lead hazard screen could be performed.
The protocols to be assessed using the Rochester study data are listed in Tables 5-3,5-4,
and 5-5. Composite samples were not collected in the Rochester study so to perform the
assessment in iv. above, the arithmetic mean of the uncarpeted and carpeted floor dust samples,
window sill dust samples, window well dust samples, and paint samples were compared to the
lead hazard screen standards, depending on the scenario chosen. Also, the Proposed Rule
recommends that dripline and mid-yard soil be sampled. The Rochester Study data only
distinguished between dripline and play area, not dripline and mid-yard. Therefore, for this
analysis, the play area soil was used as a surrogate for the mid-yard soil.
Table 5-2. Sampling Protocol Group A: Assessing the Impact of Dust Sampling from
Specific Rooms Included in a Risk Assessment.
Sampling
Protocol Group
A
A-1
4 rooms
A-2
3 rooms
A-3
2 rooms
Room Location of Single Wipe Samples
Window Sill
Floor Dust Dust
Window Well
Dust
Bedroom, Play Area, Entryway, Kitchen
Bedroom, Play Area, Entryway
&JcsijL*». ,
Bedroom, Play Area
Soil
Dripline &
Play Area
Dripline &
Play Area
Dripline &
Play Area
Paint
> 15% or > 5% of
the painted surface
is deteriorated
> 15% or > 5% of
the painted surface
is deteriorated
> 15% or > 5% of
the painted surface
is deteriorated
Definitions of the condition of the paint:
Poor: More than 15% of the paint film is peeling, chalking, flaking, blistering, or otherwise separate from the substrate.
Fair: The paint film is largely intact, but is cracked, worn or chipped (approximately 5% - 15% deteriorated)
Good: The paint film appears intact and does not chalk, flake, or peel. Less than 5% of the surface is deteriorated or
defective.
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Table 5-3. Sampling Protocol Group B: Assessing the Impact of Using Different Summary
Measures to Characterize Dust Samples for a Risk Assessment.
Sampling
Protocol Group
B
B-1
Geometric
Mean
B-2
Arithmetic
Mean
B-3
Maximum
Value
Summary Measure of All Available Samples (Wipe)
taken In the
Bedroom, Play Area, Entryway. Kitchen
Window Sill Window Well
Floor Dust Dust Dust
Geometric Mean
Arithmetic Mean
Maximum Value
Soil
Dripline &
Play Area
Dripline &
Play Area
Dripline &
Play Area
Paint
> 15% or > 5% of
the painted surface
is deteriorated
> 15% or > 5% of
the painted surface
is deteriorated
> 15% or > 5% of
the painted surface
is deteriorated
Definitions of the condition of the paint:
Poor: More than 15% of the paint film is peeling, chalking, flaking, blistering, or otherwise separate from the substrate.
Fair: The paint film is largely intact, but is cracked, worn or chipped (approximately 5% - 15% deteriorated)
Good: The paint film appears intact and does not chalk, flake, or peel. Less than 5% of the surface is deteriorated or
defective.
Table 5-4. Sampling Protocol Group C: Assessing the Outcome of a Lead Hazard Screen
Versus a Risk Assessment.
Sampling
Protocol Group
C
C-1
Full Risk
Assessment -
individual
samples
Lead Hazard
Screen
Room Location of Composite Wipe Samples
Floor Dust
Bedroom, Play
Area,
Entryway,
Kitchen
Bedroom, Play
Area,
Entryway,
Kitchen
Window Sill
Dust
Bedroom, Play
Area,
Entryway,
Kitchen
Bedroom, Play
Area,
Entryway,
Kitchen
Window Well
Dust
Bedroom, Play
Area,
Entryway,
Kitchen
Bedroom, Play
Area,
Entryway,
Kitchen
Soil
Dripline and
Play Area
NA
Paint
> 15% or >
5% of the
painted surface
is deteriorated
> 15% or >
5% of the
painted surface
is deteriorated
Definitions of the condition of the paint:
Poor: More than 15% of the paint film is peeling, chalking, flaking, blistering, or otherwise separate from the substrate.
Fair: The paint film is largely intact, but is cracked, worn or chipped (approximately 5% - 15% deteriorated)
Good: The paint film appears intact and does not chalk, flake, or peel. Less than 5% of the surface is deteriorated or
defective.
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Concurrent analyses were conducted for each Sampling Protocol and set of standards
(Interim Guidance and Proposed Rule) to compare the results of the assessments when different
standards for comparison are put into practice.
Though the performance characteristics and the risk assessor cost estimates for each
protocol within a standard of comparison were the focus of this analysis, additional statistics
were calculated to provide further characterization of the protocols. Table 5-5 lists the statistics
included in the analysis and provides a brief explanation of how the statistics were calculated.
•
Table 5-5. Summary of the Statistics Calculated to Characterize the Protocols.
• • j "i i' i1 ' ij f i ' ' "• SI, n'i't "p ' V i | 1* " '
Statistic to Characterize the Protocol <' • *. -• - ;-
Number of Homes Included in the Analysis
% of Homes Failing the Risk Assessment
% of Blood Samples 2 10//g/dL
% of Homes Failingjhe Risk Assessment Based
on One Media Assessed Individually (2 media
standard)
Sensitivity (LCB, UCB)
Specificity (LCB. UCB)
Positive Predictive Value (LCB, UCB)
Negative Predictive Value (LCB. UCB)
Basic Fee
Estimated cost of a risk
screen
Separate Fee
Description of the Calculation* |1,',';V; .'•-.,• •'•;••
Homes were included in the analysis if the dust samples
necessary for the analysis were available.
Given the media being evaluated in the protocol, this is
the percent of homes that have at least one media
sample that does not pass its associated standard.
For all homes this is the percent of children in the homes
that had a blood-lead concentration greater than or equal
to 10pg/dL.
For each medtjpindividually, this is the percent of homes
which have at least one sample which does not pass the
media standard.
The performance characteristics and confidence bounds
are calculated as discussed above.
LCB is defined as Lower 95% Confidence Bound and
UCB is defined as Upper 95% Confidence Bound.
Estimated cost of the risk assessment or lead hazard
screen performed' under the protocol. when a basic fee is
charged for the activity. (SeaigboWfor a description of
basic fees.)' ^ sT/. A^-
Estimated cost of a risk assessment or lead hazard
screen performed under the protocol when separate fees
are charge for the activity. (See above for a description
of separate fees.)
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February 15, 1999 32
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52 OBJECTIVE 2; ASSESSMENT OF ESTIMATORS OF THE TRUE AVERAGE LEAD
LEVELS AND SAMPLING PROTOCOLS USING ERROR PROBABILITIES
The statistical analysis for this objective utilized variability estimates calculated from
environmental samples in the Rochester Study, CAP Study, and Rhode Island Department of
Health data along with distributional assumptions to estimate error probabilities associated with
concluding that the unobservable, "true" average lead level in a home was above or below the
standard. The unobservable, "true" floor, window sill, and window well dust lead loading and
soil lead concentration within a home were assumed to be characterized by an average log lead
loading. The precision and accuracy of the characterization of this unobservable, "true" mean
log lead level depends on the type of statistic used to report the lead level found in the home. For
instance, using the geometric mean floor dust-lead loading to compare to the Interim Guidance
standard may better reflect the unobservable, "true" dust-lead level in the home than the
maximum floor dust-lead loading value. The analysis under this objective did the following:
A. Compared how well the maximum value, geometric mean, and arithmetic mean
characterized floor dust, window sill dust, and window well dust lead loadings and
soil lead concentration.
B. Characterized a) the probability of passing the home when the unobservable, "true"
media lead level at the home is assumed to be above the media standard (Type II
error or "False negative") and b) the probability of failing a home when the
unobservable, "true" media lead level at the home is assumed to be at or below the
media standard (Type I error or "False positive").
C. Compared the effect of different standards (i.e., Interim Guidance and Proposed
Rule standards) on the error probabilities.
An assessment of the paint lead error probabilities will not be made in this report. Paint
hazards are characterized on a component-by-component basis. This is different from soil and
dust where the samples collected are assumed to represent the "average" house level. Because of
this difference, calculation and interpretation of the paint error probabilities are more complex
and not included in the results presented.
5.2.1 Key Analysis Assumptions
Two key assumptions were made prior to the analysis.
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1. For the dust-lead and soil-lead samples, the log-transformed data followed a
normal distribution with some mean and unknown variance.
2. No room in a home was more indicative of the dust-lead hazard to a child than any
other room in the home. Given this assumption, the uncertainty associated with
measured environmental lead levels within a home are assumed to be due to room-
to-room sampling variation, within-room sampling variation, and measurement
error in collecting the samples. Similar assumptions were made with respect to soil
samples - dripline soil samples taken on more than one side of a house were
considered equally indicative of a child's exposure to soil lead at that house.
Note that floor dust, window sill dust, window well dust, dripline soil, and play area soil
were all analyzed separately in this analysis.
5.2.2 Error Probability Calculations
To compare the effectiveness of the three estimators (maximum value, arithmetic mean,
and geometric mean) in providing an accurate assessment of the assumed "true" house lead
levels, a hypothesis test was constructed:
Hoj: Ui Sf
where
u, is the unobservable, "true" average lead level within a home for each
media/component i,
S; standard for medig/component i,
i represents the medj^component (floor dust, window sill dust, window well
dust, and soil),
j represents the type of estimator (geometric mean, arithmetic mean, and
maximum value).
Under the null hypothesis, H,,, the unobservable, "true" house lead level for media/component i is
assumed to be below the media/component standard, while under the alternative hypothesis, H,,
the home's unobservable, "true" lead level for media/component i is assumed to be above or
equal to the media/component standard. Of interest are the probabilities of correct and incorrect
c?
Draft Report - Do Not Quote, Cite, Copy or Distribute February 15, 1999/34
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decisions based on the estimated media/component lead level at the home. These probabilities
are based on the Type I and Type n error probabilities.
P (Type I Error) = P(conclude H, | H0 is true)
= P(Yij*S,|u,
-------
5.2.3 Within-House Variation Calculations
Given the above key assumptions and using a general mixed effects model, the observed
log-transformed lead level for a media/component was modeled as
log(Y) = u
where
Y is the observed dust-lead or soil-lead level and is assumed to follow a normal
distribution with mean u and variance o2 = o2r + o2e; '
u is the unobservable, true average (log)dust- lead or soil-lead level within a home;
r is the room-to-room (location-to-location, in the case of soil-lead) random effect; and
e is the combined within-room (within-location, in the case of soil-lead) random effect
and random measurement error.
The room-to-room random effect, r, is a random variable and is assumed to follow a
normal distribution with mean zero and unknown variance O2r (room-to-room variation). The
combination of the within-room random effect and random error (measurement error), e, is also a
random variable and assumed to follow a normal distribution with mean zero and unknown
variance 0% fwithin-room and measurement variation). The observed log lead level, log(Y), is
then assumed to follow a normal distribution with mean u and variance o2 = o2r + o2e, where o2 is
called the within-house variation. Note that this implies the untransformed response, Y, has a
lognormal distribution.
5.2.4 Data Used to Characterize Within-House Variation
Three sets of data were used to calculate within-house variation in floor dust-lead
loadings, window sill dust-lead loadings, window well dust-lead loadings, and soil-lead
concentrations: the Rochester Lead-in-Dust Study data, the CAP Study data, and the Rhode
Island Department of Health data. Table 5-6 describes these data. As described in Section 4.1,
in the Rochester Study dust wipe samples were collected from floors, window sills, and window
wells, and soil samples were collected from the foundation of the homes and play areas in the
yard of the home. For the Rhode Island Department of Health data described in Section 4.3, dust
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Table 5-6. Data Used for the Calculation of the Within-House Components of Variation.
Data
Rochester
Study1
CAP Study1
Rhode Island
Depart-
ment of Health2
Media
Dust
Soil
Dust
Soil
Component/
Location
Floor
Window Sill
Window Well^JJjLrf^
Foundations
Boundaries ;
r
Floor /
Window Sill /
Window Well 4^
Side of House/ Foundations
Number of
Houses
204
v 196
^ 189
52
52
105
49
54
244
Number of
Samples
808
363
406
118
120
250
69
84
540
1 Components of variation were obtained from the draft final EPA report titled 'Components of Variation of Lead in
Household Dust, Soil, and Paint" [181.
1 Mixed models were fined to the data for this analysis.
wipe samples were collected from carpeted and uncarpeted floors, window wells, and window
sills in the bedroom, dining room, hallway, kitchen, living room and play area, and soil samples
were collected from the foundation of the home. No distinction between carpeted and uncarpeted
floors was made for this analysis. •
The CAP study soil samples were obtained from the exterior entryway, foundation of the
home, and boundary of the property.
Note that in the Rochester study, each house only had a single soil sample from a given
location precluding the estimation of the within-house variability for soil. In the CAP study,
multiple soil samples at a home were collected from the foundations and property boundaries
allowing the calculation of within-house soil sampling variability. For this analysis, the CAP
study variability was used in the assessment of the Rochester study data, even though the
Rochester study and CAP study were conducted in different regions of the country.
The within-house variability estimates for the Rochester study floor, window sill, and
window well dust wipes and the CAP study soil samples were extracted from the draft final
report, "Components of Variation of Lead in Household Dust, Soil, and Paint" [18]. A mixed
model analysis was performed on the Rhode Island floor dust, window sill dust, window well
Draft Report - Do Not Quote. Cite, Copy or Distribute
February 15, 1999 37
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dust, and soil sample results to obtain the within-house variability estimates for this set of data.
The specifics of the type of mixed model analysis performed can be found in [18].
Section 402 currently recommends the use of the Section 403 Interim Guidance standards
for risk assessments. When the Section 403 Proposed Rule becomes final, the standards in this
document will supersede the Interim Guidance standards. Both sets of standards were presented
earlier in Table 1-1. One exception to both the Interim Guidance and Proposed Rule made in this
analysis is to include and compare both uncarpeted and carpeted floors to the standard presented
for the uncarpeted floors. In addition, the Proposed Rule has made a distinction between play
area soil and mid-yard soil. The CAP Study data only made a distinction between foundation
and boundary soil. Therefore, for this analysis the boundary soil will be considered as a
surrogate for the mid-yard soil specified by the Proposed Rule.
5.2.5 Error Probability Calculations Associated with "Simple" and "Compound" Lead
Hazard Screens
As mentioned above, the error probabilities were calculated for a "simple" and a
"compound" lead hazard screen. The distinction between the terms "simple" and "compound"
and the associated error probability calculations are provided below.
In Section 402, when a home fails a lead hazard screen, the home is required to undergo a
full risk assessment. The probability that a home incorrectly passes or fails the lead hazard
screen is called the "simple" lead hazard screen error probability. A "compound" lead hazard
screen error probability is the probability of passin&andjailing the risk assessment, given the
home has failed the lead hazard screen (i.e., the probability that a home passes or fails testing
when a lead hazard screen is performed).
Since the "simple" lead hazard screen merely determines whether a home passes or fails a
lead hazard screen, only Type I error probabilities are presented in Section 6.2.1.2. Type I and H
error probabilities are presented for the "compound" lead hazard screen. To calculate the
"compound" lead hazard screen error probabilities, an assumption is made that the measurements
taken during a lead hazard screening stage are independent from the measurements taken during
the risk assessment stage. Given this assumption, the "compound" lead hazard screen error
probabilities are based on the following compound probabilities.
*
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Since a house fails the testing when it fails the lead hazard screen and then fails the risk
assessment, the probability of a Type I error for a "compound" lead hazard screen is:
P(fails lead hazard screen and fails risk assessment | assumed true lead level < media standard) =
s?T
P(fails-lead hazard screen | assumed true lead level < media standard) *
P(fail&risk assessment | assumed true lead level < media standard).
Under the above described hypothesis setting, this can be written as
P(Y, 2 ('/2'S,). Z, 2 (1/2*S,) | u, < (1/2*S,)) = P(Y, 2 ('/2*S,) | u, < C/2'S,)) • P(Z, 2 ('/2*S,) | u, < (JtfS,)),
where .
Yy calculated lead level for media/component i and statistic./ during lead hazard screen
Z,j calculated lead level for medi^component i and statistic./ during risk assessment
Sj standard fo^media/pomponent i (floor dust, window sill dust, window well dust,
and soil). Note: The lead hazard screen uses Vi the Interim Guidance or Proposed
Rule standard as a level for comparison.
u, assumed unobservable, "true" lead level in home
A house passes the testing either by initially passing the lead hazard screen or by failing
the lead hazard screen and then passing the risk assessment. As a result, the probability of a
Type n error for a "compound" lead hazard screen is:
P(passes lead hazard screen or
fails lead hazard screen and then passes risk assessment | true lead level 2 media standard) =
P(passes lead hazard screen | true lead level 2 media standard) +
[P(fails lead hazard screen | true lead level 2 media standard) *
P(passes risk assessment | true lead level 2 media standard)].
Under the above hypothesis setting and the descriptions of Yy, Zy, S:, and U;, this can be written
as
P(Y, < • (Vi'S.) or Y, i r/2*S,), Z, < (1/2'S.) | u, 2 (fc'S,)) =
P(Y, < C/4'S.) | H 2 (/2*S,)) + [P(Y, 2 (WS.) | JJ, 2 (1/2*S,)) • P(Z, < C
Draft Report - Do Not Quote, Cite, Copy or Distribute February 15, 1999
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5.3 OBJECTIVE 3: ASSESSMENT OF SAMPLING LOCATIONS RISK ASSESSORS MAY
WANT TO TARGET
As described in Appendix A, Section 402 does not explicitly specify the locations from
which a risk assessor is required to sample dust [5]. As stated on page A-4, a certified risk
assessor is directed as follows during a lead hazard screen at a residential dwelling: "two
composite dust samples shall be collected, one from the floors and the other from the windows in
rooms, hallways or stairwells where one or more children, age 6 and under, are most likely to
come in contact with dust." On page A-5, the specifications for a risk assessment direct the
following for the certified risk assessor: "dust samples (either composite or single-surface
samples) from the window and floor shall be collected in all living areas where one or more
children, age 6 and under, are most likely to come in contact with dust." Given these
recommendations, a risk assessor may sample dust from the child's play area or bedroom, the
kitchen, entryway or bathroom, etc.
The goal of Objective 3 was to assess dust-lead loadings from sampling locations that a
risk assessor may want to target in order to assure that the potential lead hazard to a child is best
evaluated. The first step in the analysis was to assess the correlation coefficients between blood-
lead concentration and dust-lead loadings for each sampling location and component. The
second step was to build a pathways model to be assessed using structural equation modeling.
The results from the second step provided recommendations for sampling. Each step is
described below.
5.3.1 Data Used in the Analysis
The Rochester Lead-in-Dust Study data and the Rhode Island Department of Health data
were evaluated to the appropriateness of being included in the Objective 3 analysis. A sufficient
number of homes in the Rochester Study had multiple rooms with multiple components sampled,
while the Rhode Island data source did not. As a result, only the Rochester study data were
included in the Objective 3 analysis. Table 5-7 displays the rooms sampled in the Rochester
Study and the types of components sampled in each room.
Draft Report - Do Not Quote, Cite, Copy or Distribute February 15, 1999 40
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Table 5-7. Rooms and Types of Components Sampled in the Rochester Study.
Sampled Room
Child's Bedroom
Child's Play Area
Kitchen
Interior Entryway
Living Room
Component Sampled (Number of Homes)
Floor
• (197)
• (192)
• (203)
• (179)
• (41)
Window Sill
• (163)
• (164)
• (31)
Window Well
• (150)
• (138)
• (118)
Note: The number of homes with at least one dust sample taken from the given room and component is
given in parentheses.
The rooms and components sampled varied from house to house. Therefore, throughout
this analysis, the number of dust wipe samples available was very important for determining
which relationships could be investigated.
5.3.2 Correlation Analysis
The first step in evaluating the objective was to assess the correlation between blood-lead
concentrations and dust-lead loadings from different rooms and components, as well as the
correlation among the dust-lead loadings. The strength of the relationship of loadings with
blood-lead indicated which variables may be direct pathways of lead exposure to the blood. The
strength of relationships among the loadings indicated which variables may be considered
indirect pathways of lead exposure to the blood. Direct and indirect pathways will be explained
below.
Pearson correlation coefficients (r) were calculated on the natural logarithmically-
transformed blood-lead concentrations and dust-wipe lead loadings. If the absolute value of r
was near one, this implied the linear association between the two variables being evaluated was
strong. If the absolute value of r was near zero, then this implied there was very little to no linear
association between the two variables. These correlation coefficients provided indications of
which rooms and components should be included in the pathways analysis.
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February 15. 1999 41
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5.3.3 Pathways Analysis
Figure 5-3 illustrates the lead pathways that were assessed using the Rochester Study
data. The pathways analysis was performed on data for 83 homes. These homes had data for all
components specified within Figure 5-3. To keep the number of homes from being reduced
further, dust-lead loadings from living room components and from kitchen window wells were
not included in the pathways analysis (note that including kitchen window well samples would
have excluded an additional 28 homes). The pathways model was created to assess, using
structural equation modeling (SEM), the direct and indirect association between a sampling
location or component and blood-lead concentrations. Several structural equation models
describing pathways by which blood is exposed to environmental-lead have been assessed in the
past, and the results have been published in the literature [13,14,15,16,17].
Bedroom Window
Well Dust
Bedroom Window
Sill Dust
Bedroom Floor Dust
Kitchen
Poor Dust
t
1
Play Area Window
SillC
i
Play Area
Well
Just *
k
Window
Dust
r
Play
Area
1
Roor
Interior Entryway
17
Figure 5-3. Pathways of Lead Exposure Investigated Using the Rochester Study Data.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 42
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To explain how structural equation modeling relates to other more commonly-used
statistical analysis techniques, and to explain the meaning of direct' and 'indirect' effects on the
blood-lead concentration, consider Figure 5-3 which shows the pathways which were assessed in
this analysis.
Figure 5-3 contains the direct effects on blood-lead of
• bedroom floor, window sill, and window well dust,
• kitchen floor dust,
• interior entryway floor dust, and
• play area floor, window sill, and window well dust
and the indirect effects on blood-lead of
• bedroom floor dust via the play area floor dust
• bedroom window sill dust via the bedroom floor dust,
• bedroom window well dust via the bedroom window sill dust or the bedroom floor
dust,
• play area floor via the bedroom floor dust,
• play area window sill via the play are floor dust,
• play area window well dust via the play area window sill dust or the play area floor
dust,
• kitchen floor dust via the play area floor dust, and
• interior entryway dust via the play area floor dust, bedroom floor dust, or the kitchen
floor dust.
To statistically assess these pathways, a structural equation model (SEM) is constructed.
Equations (1) through (6) below mathematically represent the pathways presented in Figure 5-3.
(1) Blood = Bedroom Floor Dust + Bedroom Window Sill Dust + Bedroom Window
Well Dust + Play Area Floor Dust + Play Area Window Sill Dust + Play Area
Window Well Dust + Kitchen Floor Dust + Interior Entryway Floor Dust
(2) Kitchen Floor Dust = Play Area Floor Dust + Interior Entryway Floor Dust
(3) Play Area Floor Dust = Play Area Window Sill Dust + Play Area Window Well Dust
+ Bedroom Floor Dust + Kitchen Floor Dust + Interior Entryway Floor Dust
Draft Report - Do Not Quote, Cite. Copy or Distribute February 15, 1999 43
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(4) Bedroom Floor Dust = Bedroom Window Sill Dust + Bedroom Window Well Dust +
Play Area Floor Dust + Interior Entryway Floor Dust
(5) Play Area Window Sill Dust = Play Area Window Well Dust
(6) Bedroom Window Sill Dust = Bedroom Window Well Dust
Similar to multiple regression or analysis of variance (ANOVA), the direct effect of
• bedroom floor dust, bedroom window sill dust, bedroom window well dust, play area
floor dust, play area window sill dust, play area window well dust, kitchen floor dust,
interior entryway floor dust on blood in equation (1),
• play area floor dust and interior entryway floor dust on kitchen floor dust in equation
(2),
• play area window sill dust, play area window well dust, bedroom floor dust, kitchen
floor dust, interior entryway floor dust on play area floor dust in equation (3),
• bedroom window sill dust, bedroom window well dust, play area floor dust, interior
entryway floor dust on bedroom floor dust in equation (4),
• play area window well dust on play area window sill dust in equation (5), and
• bedroom window well dust on bedroom window sill dust in equation (6)
can be examined using SEM. Unlike multiple regression and ANOVA, the indirect effects listed
above can be assessed using SEM by evaluating all six equations simultaneously.
Note that the pathways analysis performed for Objective 3 is a little different from
pathways analyses that have been discussed in the literature [13,14,15,16,17]. In the literature,
generally, all the sources from which lead may enter into a child's environment are examined and
included in the analysis - sources such as a floor dust, window sill dust, window well dust, soil,
paint, hand dust, pica, etc. The floor dust, window sill dust, and window well dust variables in
the published analyses usually represent an average floor dust-lead, window sill dust-lead, and
window well dust-lead loading or concentration, respectively, over all rooms sampled (such as
bedroom, play area, kitchen, living room, entryway, etc.). The analysis in this report is slightly
different. First, the interior dust-lead sources are isolated: floor dust-lead, window sill dust-lead,
and window well dust-lead, and no other sources of lead are considered. Second, the individual
room floor dust, window sill dust, and window well dust-lead loadings are assessed, not the
Draft Report - Do Not Quote, Cite, Copy or Distribute February 15. 1999 44
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average over all rooms. For instance, in this analysis, the effect of bedroom floor dust, play area
floor dust, kitchen floor dust, and interior entryway floor dust-lead loadings on a child's blood
lead concentration are assessed, while in the published analyses, the average floor dust-lead
loading over the bedroom, play area, kitchen, and interior entryway may have been assessed.
Not averaging the dust-lead loadings in this report allows an assessment of the effect of sampling
location on identifying hazards.
Draft Report - Do Not Quote, Cite. Copy or Distribute February 15. 1999 45
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6.0 RESULTS
This section presents the findings and results from the analyses discussed in Section 5.
Section 6.1 presents the results of the risk assessor cost interviews and performance
characteristics analysis. Section 6.2 provides the error probabilities analysis results and
Section 6.3 presents the results of the correlation and pathways analyses.
6.1 OBJECTIVE 1; PROBABILITY OF CORRECTLY IDENTIFYING A LEAD-BASED PAINT
HEALTH HAZARD IN SINGLE FAMILY HOUSING AND THE COSTS ASSOCIATED
WITH THE RISK ASSESSMENT
6.1.1 Risk Assessor Cost Summaries
Caution: As discussed in Section 5.1, the sample of risk assessors providing cost data was not
selected to be a statistically representative sample. Data -were collected from nine
contractors in nine different states. Initial interviews were conducted in May, 1997,
with follow-up interviews of seven contractors conducted in April, 1998.
Four types of summaries of the risk assessor cost interviews are provided below:
• Average total costs of an activity: risk assessment, lead hazard screen, inspection, and
risk assessment/inspection.
• Average cost per environmental sample.
• Average number of environmental samples collected.
• Average, minimum, maximum, and sample size or frequency and sample size for all
responses on the questionnaire.
Note that as discussed in Section 5.1, each contractor was assigned an ID corresponding
to the region in which the contractor is located (northeast=NE, south=S, and west=W). These
ID's are used to represent the contractors throughout this summary.
6.1.1.1 Summary of the Risk Assessment. Lead Hazard Screen. Inspection, and Risk
Assessment/Inspection Costs
Figure 6-1 contains of the total costs for a risk assessment, lead hazard screen, inspection,
and risk assessment/inspection, as specified by each contractor. The average across all nine
contractors is specified by the results labels "overall," and are also presented in Table 6-1.
Draft Report - Do Not Quote. Cite, Copy or Distribute February 15. 1999 46
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0
S.
33
CO
•D
0
D
0
z
0
D
o
r-f
CD
0
CD
O
0
0
—\
0
Risk Assessment
$3,000 '
^^ $2.500 '
Ut $2.000 '
(/>
0
O $1,500 "
o $1,000 -
$500 -
$1,520
I
$1£42 I $900
$659 i 1
g $A25 $49° 1 1
1 'n5 'n™ 0 11 1
$759 r
$260
I
$0 ,111,1,,,
Overall NE-1 NE-2 NE-3 NE^» S-1 S-2 S-3 W-1 W-2
n Basic Fee • Separate Fee D Overall
Inspection
$3,000 -
^_^ $2,500 '
j2 $2,000 -
in
o
O $1,500 •
"ro
o $1,000 •
I-
$500 -
$1.530
I $978
$0 i i i , i ,
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2
I $600
n
I
S-3 W-1
$35(1
n
W-2
D Basic Fee • Separate Fee B Overall
CD
0"
Lead Hazard Screen
$3,000 '
__ $2,500 '
y> $2,000 •
(A
o
O $1,500 '
2
o $1,000
1-
$500
$525
I 'r? W 1
$626
|$200 $200
n n
Overall NE-1 NE-2 NE-3 NE^t S-1 S-2 S-3 W-1 W-2
D Basic Fee • Separate Fee B Overall
Risk Assessment/Inspection
$3.000 -
_$2,500 '
jfl $2,000 -
10
o
O $1,500 '
"o $1,000 -
$500 -
$2
$1
1
!
78
$515
$235 1
, n , , 1
25
11.318
I $900
1 $550
1 r~i
1 1
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2 S-3 W-1 W-2
D Basic Fee • Separate Fee D Overall
CD
CD
CD
Figure 6-1. Total Costs for a Risk Assessment, Inspection, Lead Hazard Screen, and a Risk Assessment/Inspection.
-------
Table 6-1. Average Total Cost of a Risk Assessment, Lead Hazard Screen, Inspection, and
Risk Assessment/Inspection With and Without Extremely High Costs.
Activity
Risk Assessment
Lead Hazard Screen
Inspection
Risk Assessment/Inspection
Average Total Cost ($)
All Surveyed Contractors
$659
$304
$569
$1,178
Excluding Three Contractors
(S-1. S-2, S-3) with High Costs
$435
$169
$308
$550
Figure 6-1 shows that an overall average total cost for a risk assessment is $659, $304
for a lead hazard screen, $569 for an inspection, and $1,178 for a risk assessment/inspection.
Total costs ranged from $90 for a lead hazard screen by a contractor in the Northeast to $2,825
for a risk assessment/inspection by a contractor in the South. A large disparity in prices exists
among the contractors that appears to be related to the extensiveness of lead poisoning •paint
prevention programs in a region. For instance, regions that have well established and very active
prevention programs (such as the northeast) have lower inspection and screen costs .than regions
which have less active programs (such as the south). The contractors represented by dark blocks
in Figure 6-1 generally charge a separate fee for each component of the activity and strongly
influence the overall average with their extremely high costs. The fees for the three contractors
in the South were typically higher than those reported by the other contractors. When the costs
for these three contractors were removed and the averages recalculated, as shown in Table 6-1,
the average total cost was $435, $169, $308, and $550 for a risk assessment, lead hazard screen,
inspection, and risk assessment/inspection, respectively. This is a reduction of one-half to one-
third of the overall average cost of the activity. These reduced averages may be more
representative of the average cost of these activities when promulgation of the Section 403 rule
makes these activities more commonplace.
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Reasons for the disparity in costs among the contractors were not explored with the
survey respondents during the initial interview. Through a round of follow-up phone calls, one
of the contractors with the highest costs indicated that he thought his prices were higher due to
the fact that they perform fewer risk assessment activities in his area of the country. Comments
from the other contractors with higher costs were not obtained.
Note during the follow-up interviews, the seven contractors who could be reached
indicated that the costs of performing a risk assessment, lead hazard screen, inspection, and risk
assessment/inspection had generally stayed the same, with some contractors reducing the costs
because the 1997 HUD Guidelines revision of Chapter 7 reduced the number of XRF readings
needed for the testing.
For contractors who charge separate fees for the visual assessment, environmental
sampling, and report of a risk assessment, lead hazard screen, inspection, and risk
assessment/inspection, summaries of these separate fees are presented in Figures 6-2 through 6-5.
The top chart in each figure corresponds to visual assessment costs, the middle chart represents
environmental sampling costs, and the bottom chart represents report costs. Across all four
activities, the visual assessment costs ranged from $150 for a risk assessment and lead hazard
screen to $1,500 for a risk assessment/inspection. All contractors but one had visual assessment
costs of $750 or less. The typical environmental sampling costs ranged from $19 for an
inspection performed by a contractor from the south to $1,325 for a risk assessment/inspection
performed by the same contractor. The reports for each of the activities ranged in costs from $50
for a risk assessment report to $500 for a risk assessment, inspection, or risk assessment/
inspection report. Note that the contractors which charged separate costs for each component of
an activity generally had higher costs than those that charged the basic fee.
Draft Report - Do Not Quote. Cite, Copy or Distribute February 15, 1999 49
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Risk Assessment
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2 S-3 W-1 W-2
g $1.200
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2 S-3 W-1 W-2
$0
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2 S-3 W-1 W-2
Figure 6-2. Estimated Costs ($) of the Visual Assessment, Typical Environmental
Sampling, and the Risk Assessment Report for a Risk Assessment.
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February 15, 1999 50
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Lead Hazard Screen
$250
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2 S-3 W-1 W-2
$225
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2 S-3 W-1 W-2
$300
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2 S-3 W-1 W-2
Figure 6-3. Estimated Costs ($) of the Visual Assessment, Typical Environmental
Sampling, and the Lead Hazard Screen Report for a Lead Hazard Screen.
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February 15, 1999 51
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Inspection
$800
I
I
1
E
M
I
|
5
$750
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2 S-3 W-1 W-2
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2 S-3 W-1 W-2
$600
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2 S-3 W-1 W-2
Figure 6-4. Estimated Costs ($) of the Visual Assessment, Typical Environmental
Sampling, and the Inspection Report for an Inspection.
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February 15, 1999 52
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Risk Assessment/Inspection
$1.600
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2 S-3 W-1 W-2
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2 S-3 W-1 W-2
Overall NE-1 NE-2 NE-3 NE-4 S-1
S-3 W-1 W-2
Figure 6-5. Estimated Costs ($) of the Visual Assessment, Typical Environmental
Sampling, and the Risk Assessment/Inspection Report for a Risk
Assessment/Inspection.
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6.1.1.2 Summary of the Costs per Environmental Sample
Table 6-2 below presents the average cost per environmental sample (dust, soil, water)
collected for each activity. The averages were calculated over all media/components and are
presented over all contractors and for each contractor individually.
Table 6-2. Average Cost Per Environmental Sample (Dust, Soil, Water) Collected for a Risk
Assessment, Lead Hazard Screen, Inspection, and Risk Assessment/Inspection.
By Contractor.
j=^=^=^==
Contractor
Overall
NE-1
NE-2
NE-3
NE-4
S-1
S-2
S-3
W-1
W-2
Average Total Costs ($)<"
Minimum Costs - Maximum Costs
Risk Assessment
$18.20
$5.00-$30.00
$15.00
$15. 00- $15.00
$10.00
$10.00- $10.00
$25.00
$25.00-$25.00
$20.00
$20.00-$20
$22.88
$16.50-$30.00
$25.00
$25.00-$25.00
$19.50
$18.50-420.00
$5.00
$5.00-$5.00
$15.00
$15.00-$ 15.00
Lead Hazard Screen
$20.64
$10.00-$25.00
(b)
$11.00
$10.00-$ 12.00
(b)
-------
Overall, the average total cost per sample ranged from $16 per sample for the risk
assessment/inspection to $21 per sample for the lead hazard screen. The lowest cost per sample
was $5 for a contractor in the west region, while the highest cost per sample was $25 for a
contractor in the south region. Generally, across the four activities, the costs per sample
remained nearly the same for a given contractor.
Table 6-3 presents the average collection cost, average analysis cost, and average total
cost, per environmental sample, for each of the media/components sampled. As discussed in
Section 5, the total cost was the sum of the collection and analysis costs. As only one contractor
reported collection costs separately, total costs typically reflect just the cost of analysis.
Table 6-3. Average Cost Per Sample Collected for Sampling Performed by a Certified Risk
Assessor During a Risk Assessment, Lead Hazard Screen, Inspection, or Risk
Assessment/Inspection For All Contractors.
Media
Dust
Paint
Soil
Water
Type of Sample
Composite
Single
Paint Chips -
Composite
Paint Chips -
Single
XRF
Composite
Single
Average Cost Per Sample ($)
Minimum Cost - Maximum Cost
(N = # of Contractors Responding)
Collection Cost
$10.00
$10.00- $10.00
(N=1)
$10.00
$10.00- $10.00
(N = 1)
(a)
(a)
(a)
$15.00
$15.00- $15.00
(N=1)
(a)
$15.00
$15.00- $15.00
(N=1)
Analysis Cost
$17.50
$15.00- $20.00
(N = 3)
$18.39
$ 5.00 - $30.00
(N = 9)
(a)
(a)
(a)
$16.05
$ 5.00 - $25.00
(N = 7)
(a)
$11.82
$ 5.00- $15.00
(N = 5)
Total Cost
$20.00
$15.00 -$25.00
(N = 3)
$18.71
$ 5.00 - $30.00
(N = 9)
(a)
(a)
(a)
$17.48
$ 5.00 - $25.00
(N = 7)
(a)
$13.18
$ 5.00 - $25.00
-------
Table 6-3 shows that the average total costs per environmental sample were highest for
the three contractors that collected dust composite samples, at $20 per sample, with costs ranging
from $15 to $25 per composite sample. The lowest cost per sample was $13 for water, where
five contractors reported costs ranging from $5 to $25 per sample. No breakdowns on the cost
per sample for paint were reported by any of the contractors during the initial interviews. Tables
G-l through G-9 in Appendix G present similar summaries for each of the contractors.
The follow-up interviews found that for contractor S-3, the risk assessment dust sampling
costs were reduced from $20 per sample to $15 per sample for collection and analysis, but the
soil composite sampling increased from $20 per sample to a range of $35 to $50 per sample for
collection and analysis. In the initial interview, contractor S-2 specified no collection cost for
dust, soil, or paint sampling under any of the activities, but indicated a $15 collection cost in the
follow-up interview. In the follow-up interview, contractor NE-3 indicated an increase in costs
for dust, soil, and water sampling from $25 for collection and analysis to $35 and an increase in
XRF testing from $125 for the first hour to $150. Contractor NE-2 indicated in a follow-up
interview that the analysis costs for soil samples increased from $10 to $12, but the basic fee for
an inspection decreased from $250 to $195.
In the initial interviews, no paint sampling information was obtained, but during the
follow-up interviews one contractor indicated that it now charges $50 per hour for XRF testing,
two others charge a flat fee of $200 and $365 for XRF sampling, and two other contractors
charge $15 per sample for collection and analysis of paint chips.
6.1.1.3 Summary of the Number of Environmental Samples Collected
The average number of samples (of all environmental media) collected for a particular
environmental assessment activity at a given house is summarized in Table 6-4 for each
contractor and over all contractors. Over all contractors, the average number of samples
collected ranged from 5 for a lead hazard screen to 41 for an inspection. The fewest number of
samples reported was two for a risk assessment, inspection, or risk assessment/inspection
performed by contractor NE-1. The highest number of samples reported was 250 for a risk
assessment and inspection by contractor NE-2, which represented the expected number of XRF
measurements.
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Table 6-4. The Average Number of Environmental Samples Collected for a Risk
Assessment, Lead Hazard Screen, Inspection, and Risk Assessment/Inspection,
Over All Media, By Contractor.
Contractor
Overall
NE-1
NE-2
NE-3
NE-4
S-1
S-2
S-3
W-1
W-2
Average Number of Samples Collected
Minimum # Samples - Maximum # Samples
Risk Assessment
18
1-250
2
1-3
116
6-250
4
2-8
7
7-7
36
20-50
13
5-25
8
3-10
4
3-5
(b)
Lead Hazard Screen
5
1-10
(a)
5
1-10
(a)
10
10-10
(a)
3
2-5
6
3-10
(a)
la)
Inspection
42
1-250
2
1-5
225
200-250
65
65-65
10
10-10
50
50-50
30
30-30
28
15-40
4
3-4
(a)
Risk Assessment/
Inspection
10
1-50
2
1-5
7
6-8
(a)
9
7-10
36
20-50
15
5-30
15
7-40
3
1-5
(b)
8 The number of samples collected for the activity was not reported by the contractor.
This contractor generally did not perform risk assessments, therefore, no applicable information was
available.
Table 6-5 presents the average number of dust, paint, soil, and water samples, calculated
over the four activities and all contractors. On average, 4 composite dust samples, 8 single dust
samples, 91 XRF measurements, 3 composite soil samples, and one water sample were collected
when one of the four activities were performed. These averages are all in line with the
*
recommendations given in the Guidance documents. The follow-up interviews indicated that
generally, the number of samples remained the same with only the XRF samples being reduced
because of updates to; the 1997 HUD Guidelines. Similar summaries are provided in Tables G-l
through G-9 in Appendix G for each of the contractors.
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Table 6-5. Average Number of Samples Collected for Sampling Performed by a Certified
Risk Assessor During a Risk Assessment, Lead Hazard Screen, Inspection, or
Risk Assessment/lnspection/or All Contractors.
Media
Dust
Paint
Soil
Water
Type of Sample
Composite
Single Area
Paint Chips - Composite
Paint Chips - Single Area
XRF
Composite
Single Area
Average Number of Samples
Minimum # Samples - Maximum # Samples
(N = # of Contractors Responding)
4
2-8
(N = 3)
8
2-25
(N = 8)
(a)
(a)
91
10-250
(N = 3)
3
1 - 10
(N = 7)
(a)
1
1 - 1
(N = 2)
8 The number of samples collected was not reported by any contractor.
6.1.2 Performance Characteristic Analysis Results
As discussed in Section 5.1, only the Rochester Lead-in-Dust Study data had the
appropriate information to assess Sampling Protocols A, B, and C outlined in Tables 5-4,5-5,
and 5-6, respectively. Using the performance characteristic summary measures discussed in
Section 5.1, the results presented below assess
1. the impact of the number of rooms in which dust wipe samples are obtained on the
outcome of a full risk assessment (Sampling Protocol A),
2. the impact of various methods of characterizing the dust wipe samples on the
outcome of a full risk assessment (Sampling Protocol B),
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3. the outcome of a fall risk assessment versus the outcome of a lead hazard screen
(Sampling Protocol C),
4. the impact of changing from the Interim Guidance standards to the Proposed Rule
standards on a full risk assessment and a lead hazard screen, and
5. the estimated cost of performing a risk assessment or lead hazard screen.
6.1.2.1 Results of Protocol A Analysis: Assessment of the Impact of the Number of
Rooms in Which Dust Wipes Are Collected on a Risk Assessment Outcome
As discussed in Section 5.1 and summarized in Table 5-2, Protocol A was designed to
assess the impact of obtaining dust wipe samples from floors, window sills, and window wells in
two, three, and four specified rooms where, 6,7, and 8 to 9 dust wipe samples were obtained,
respectively, during a risk assessment. The two rooms sampled were the bedroom and play area;
the bedroom, play area, and entryway were the three rooms sampled; and the bedroom, play area,
entryway, and kitchen were the four rooms sampled. The child's bedroom and primary play area
were always sampled since the HUD Guidelines recommend sampling occur in these two rooms.
The entryway and kitchen were sampled to assess how additional sampling (allowed under the
HUD Guidelines) may affect the outcome of a risk assessment as characterized by the
performance characteristics.
Tables 6-6 and 6-7 present the performance characteristic summary statistics when a fall
risk assessment is performed under the Interim Guidance and Proposed Rule standards,
respectively, using Protocol A and XRF measurements from surfaces with > 5% deteriorated
paint. Under both sets of standards, the impact of sampling from additional rooms appears to be
minimal in terms of the number of homes that fail the assessment and the protectiveness of the
sampling. The number of homes that fail the assessment remains constant at 85.5% under the
Interim Guidance standards and slightly increases from 74.7% to 77.1% under the Proposed
Rule. Under the Interim Guidance all four performance characteristics remain constant at 88.2%
for sensitivity, 15.2% for specificity, 21.1% for PPV, and 83.3% for NPV. The sensitivity, PPV,
and NPV increase from 82.4% to 88.2%, 22.6% to 23.4%, and 85.7% to 89.5% for the Proposed
Rule as the number of rooms sampled increases from 2 to 4 rooms. The specificity decreases
from 27.3% to 25.8%. Though there are some differences, a check of the lower and upper
confidence bounds indicates that these differences are not statistically significant indicating that
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Table 6-6. Sampling Protocol A: Assessment of the Impact of the Number and Type of
Rooms in Which Dust Wipe Samples are Collected on the Outcome of a Full
Risk Assessment, Using the Interim Guidance Standards (XRF Paint Samples
from Surfaces With > 5% Deteriorated Paint).
..
==^=====
# Homes included in analysis
% of Homes Failing the Risk Assessment
(# Homes Failing / # Homes)
% of Blood Samples 2 10 j/g/dL
Sampling Protocol Group A
A-1 (4 Rooms)
=^=^^==
83
8-9
85.5%
A-2 (3 Rooms)
=^^==^=^
83
7
85.5%
A-3 (2 Rooms)
=^=^==
83
6
85.5%
20.5%
% of Homes Failing the Risk Assessment on Media Standards U Media Standard)
(# of Homes Failing/* Homes in which samples were collected)
Uncarpeted Floors Only
Window Sill
Window Well
Soil
Dripline Soil Only
Play Area Soil Only
Paint (> 5% deteriorated)
9.6% (8/83)
3.9% (3/76)
7.3% (6/82)
21. 7% (18/83)
8 1.9% (68/83)
7.8% (6/77)
7.8% (6/77)
0% (0/40)
79.7% (51/64)
7.2% (6/83)
3.9% (3/76)
6.9% (4/58)
21. 7% (18/83)
80.7% (67/83)
7.8% (6/77)
7.8% (6/77)
0% (0/40)
79.7% (51/64)
Sensitivity
(LCB, UCB)
Specificity
(LCB, UCB)
Positive Predictive Value
(LCB, UCB)
Negative Predictive Value
(LCB. UCB)
88.2%
(63.6%, 98.5%)
15.2%
(7.5%, 26.1%)
21.1%
(12.3%, 32.4%)
83.3%
(51.6%, 97.9%)
=^^^^^^^^^^^=^=
88.2%
(63.6%, 98.5%)
15.2%
(7.5%, 26.1%)
21.1%
(12.3%, 32.4%)
83.3%
(51.6%, 97.9%)
' ^^^^^^^^^^=
2.4% (2/83)
1.3% (1/75)
3.4% (1/29)
21. 7% (18/83)
80.7% (67/83)
7.8% (6/77)
7.8% (6/77)
0% (0/40)
79.7% (51/64)
88.2%
(63.6%, 98.5%)
15.2%
(7.5%, 26.1%)
21.1%
(12.3%. 32.4%)
83.3% I
(51.6%. 97.9%) II
Note: 1. Floor, window sill, and window well samples were collected as dust wipes,
core sample, and XRF measurements were taken for paint.
2. See Table 5-3 for definitions of sampling protocols A-1, A-2, and A-3.
soil was collected as a
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Table 6-7 Sampling Protocol A: Assessment of the Impact of the Number and Type of
Rooms in Which Dust Wipe Samples are Collected on the Outcome of a Full Risk
Assessment, Using the Proposed Rule Standards (XRF Paint Samples from
Surfaces With >5% Deteriorated Paint).
# Homes included in analysis
Number of individual samples per home
% of Homes Failing the Risk Assessment
(# Homes Failing / # Homes)
% of Blood Samples i 10//g/dL
Sampling Protocol Group A
A-1 (4 Rooms)
83
8-9
77.1%
A-2 (3 Rooms)
7
75.9%
A-3 (2 Rooms)
6
74.7%
20.5%
% of Homes Failing the Risk Assessment on Media Standards U Media Standard)
(# of Homes Failing/0 Homes in which samples were collected)
All Floors
Carpeted Floors Only
Uncarpeted Floors Only
Window Sill
Window Well
Soil (Average of average dripline
and average play area)
Dripline Soil Only
Play Area Soil Only
Paint {> 5% deteriorated)
Performance Characteristics
Sensitivity
(LCB, UCB)
Specificity
(LCB, UCB)
Positive Predictive Value
(LCB. UCB)
Negative Predictive Value
(LCB UCB)
10.8% (9/83)
2.6% (2/76)
9.8% (8/82)
28.9% (24/83)
9.6% (8/83)
2.6% (2/76)
12.1% (7/58)
28.9% (24/83)
4.8% (4/83)
1.3% (1/75)
10.3% (3/29)
28.9% (24/83)
NA
27.3% (21/77)
27.3% (21/77)
27.3% (21/77)
NA
NA
79.7% (51/64)
79.7% (51/64)
88.2%
(63.6%. 98.5%)
25.8%
(15.8%. 38.0%)
23.4%
(13.8%. 35.7%)
89.5%
(66.9%, 98.7%)
82.4%
(56.6%. 96.2%)
25.8%
(15.8%, 38.0%)
22.2%
(12.7%, 34.5%)
85.0%
(62.1%, 96.8%)
79.7% (51/64)
82.4%
(56.6%, 96.2%)
27.3%
(17.0%. 39.6%)
22.6%
(12.9%. 35.0%)
85.7%
(63.7%, 97.0%)
Note: 1. Floor and window sill samples were collected as dust wipes, soil was collected as a core, and XRF
measurements were taken for paint. Window well samples are not required under the Proposed
Rule.
2. See Table 5-3 for definitions of sampling protocols A-1. A-2, and A-3.
3 NA indicates that these samples were not included in the analysis.
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the effect of the additional rooms in sampling does not statistically significantly affect the
outcome of the risk assessment as measured by the performance characteristics. Tables G-10 and
G-l 1 in Appendix G show similar results when the analysis is run using XRF samples obtained
from surfaces with > 15% deteriorated paint.
Since the focus of the analysis was on dust wipe sampling in additional rooms,
performance characteristics were calculated excluding the soil and paint sampling. Table 6-8
presents a summary of these results.
Table 6-8. Sampling Protocol A: Summary of the Assessment of the Impact of the
Number and Type of Rooms in Which Dust Wipe Samples are Collected on the
Outcome of a Risk Assessment, Using the Interim Guidance and Proposed Rule
Standards (No Soil and Paint Sampling Included).
# Homes included in
analysis
% of Homes Failing the
Risk Assessment
Sampling Protocol Group A
Interim Guidance
A-1
(4 Rooms)
A-2
(3 Rooms)
A-3
(2 Rooms)
Proposed Rule
A-1
(4 Rooms)
83
81.9%
80.7%
80.7% 33.7%
Performance Characteristics
Sensitivity
Specificity
Positive Predictive
Value
Negative Predictive
Value
88.2%
19.7%
22.1%
86.7%
88.2%
21.2%
22.4%
87.5%
88.2%
21.2%
22.4%
87.5%
^=^^=^^
64.7%
74.2%
39.3%
89.1%
=^^==
A-2
(3 Rooms)
32.5%
58.8%
74.2%
37.0%
87.5%
A-3
(2 Rooms)
30.1%
58.8%
77.3%
40.0%
87.9%
Note: See Table 5-3 for definitions of sampling protocols A-1, A-2, and A-3.
Table 6-8 shows that even when focusing only on the dust wipe samples there is very
little difference in the performance characteristics as the number of rooms sampled increases and
the sampling is isolated to only the dust wipe sampling. The details of the analysis are presented
in Tables G-l2 and G-l3 in Appendix G where the confidence intervals about the performance
characteristics indicate that the small differences observed are not statistically significant.
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In the Rochester data, only floor samples were obtained in the interior entryway and floor
and/or window well samples were obtained in the kitchen. Of the 83 homes included in this
analysis, entryway floors were sampled in 83 homes, kitchen floors in 83 homes, and kitchen
window wells in 55 homes. Given the high number of homes that had samples taken in the
kitchen and entryway, Table 6-9 summarizes the additional number of homes that failed the
media/component standard when the entryway was sampled after the bedroom and play area had
been sampled and kitchen was sampled after the bedroom, play area, and entryway had been
sampled. As can be seen in Table 6-9 very few additional homes failed the media standards
when the entryway and then the kitchen were sampled. This helps explain why the performance
characteristics did not change significantly when the additional rooms were sampled.
Table 6-9. Number of Additional Homes that Failed the Dust Standards when the
Entryway and Kitchen were Sampled.
Component
Floors
Carpeted
Uncarpeted
Window Sills
Window Wells
Number of additional homes that failed the Dust Standards
Interim Guidance
Entryway
(Bedroom and Play
Area are Baseline)
4
2
3
0
0
Kitchen
(Bedroom, Play
Area, and
Entryway are
Baseline)
2
0
2
0
1
Proposed Rule
Entryway
(Bedroom and Play
Area are Baseline)
4
1
4
0
0
Kitchen
(Bedroom, Play
Area, and
Entryway are
Baseline)
1
0
1
0
0
It should be noted that the results of these analyses are based on an assumption that at
least 6 samples are collected when 2 rooms are sampled. If fewer samples were collected when
only examining 2 rooms (e.g. 2 samples in 2 rooms or 4 samples in 4 rooms) the results may be
different.
Note that the differences observed between the Interim Guidance and Proposed Rule
performance characteristics will be discussed below in Section 6.1.2.4.
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6.1.2.2 Results of Protocol B Analysis: Assessment of the Impact of Various Methods
of Characterizing Dust Wine Samples on the Outcome of a Risk Assessment
Currently, when a certified risk assessor performs a risk assessment under EPA's Interim
403 Guidance or HDD's 1995 Guidelines, a home will fail the risk assessment if any sample
does not pass the standards outlined in each document. Under EPA's Proposed Rule, a home
fails the risk assessment if the arithmetic mean of all uncarpeted floor dust wipe samples or
window sill dust wipe samples or the average of the dripline and mid-yard soil samples is above
the proposed standards.
The purpose of this analysis was to assess the effectiveness of using an arithmetic mean,
geometric mean, or maximum value of the dust wipe samples as a method of characterizing the
dust lead in a home under the different standards (see Table 5-3). Tables 6-10 and 6-11 present
the performance characteristic results using a full risk assessment, XRF samples taken from
surfaces with > 5% deteriorated paint, and the Interim Guidance and Proposed Rule standards,
respectively.
Tables 6-10 and 6-11 show that the percentage of homes that fail the risk assessment are
highest for the maximum value and lowest for the geometric mean. Under the Interim Guidance
sensitivity and NPV were highest for the maximum value and lowest for the geometric mean.
Under the Proposed Rule, the sensitivity was highest for the maximum value and arithmetic
mean and lowest for the geometric mean while the NPV was highest for the arithmetic mean and
lowest for the maximum value.
The percentage of homes that failed the risk assessment under the Interim Guidance
ranged from 77.7% for the geometric mean to 85.7% for the maximum value, and under the
Proposed Rule standards from 73.2% for the geometric mean to 79.5% for the maximum value.
For both standards, the failure rates when using the arithmetic mean were between the geometric
mean and maximum value failure rates.
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Table 6-10. Sampling Protocol B: Assessment of the Impact of Various Methods of
Characterizing Dust Wipe Samples Obtained in a Full Risk Assessment, Using
the Interim Guidance Standards (XRF Paint Samples from Surfaces With
>5% Deteriorated Paint).
# Homes included in analysis
% of Homes Failing the Risk Assessment
(# Homes Failing / # Homes)
% of Blood Samples 2 10//g/dL
Sampling Protocol Group B
B-1
(Geometric Mean)
112
77.7%
B-2
(Arithmetic Mean)
112
81.3%
B-3
(Maximum Value)
112
85.7%
21.4%
% of Homes Failing the Risk Assessment on Media Standards U Media Standard)
{# of Homes Failing/* Homes in which samples were collected)
All Floors
Carpeted Floors Only
Uncarpeted Floors Only
Window Sill
Window Well
Soil
Dripline Soil Only
Play Area Soil Only
Paint (> 5% deteriorated)
1.8% (2/112)
0.0% (0/102)
1.8% (2/109)
16.1% (18/112)
67.9% (76/1 12)
7.6% (8/105)
7.7% (8/104)
0% (0/52)
77.3% (68/88)
3.6% (4/1 12)
1.0% (1/102)
2.8% (3/109)
22.3% (25/1 12)
75.9% (85/1 12)
7.6% (8/105)
7.7% (8/104)
0% (0/52)
77.3% (68/88)
8.0% (9/1 12)
3.9% (4/102)
5.5% (6/109)
27.7% (31/112)
83.0% (93/112)
7.6% (8/105)
7.7% (8/104)
0% (0/52)
77.3% (68/88)
Performance Characteristics
Sensitivity
(LCB, UCB)
Specificity
(LCB, UCB)
Positive Predictive Value
(LCB, UCB)
Negative Predictive Value
(LCB, UCB)
83.3%
(62.6%, 95.3%)
23.9%
(15.4%, 34.1%)
23.0%
(14.6%, 33.2%)
84.0%
(63.9%, 95.5%)
87.5%
(67.6%, 97.3%)
20.5%
(12.6%, 30.4%)
23.1%
(14.9%, 33.1%)
85.7%
(63.7%, 97.0%)
91.7%
(73.0%, 99.0%)
15.9%
(9.0%. 25.2%)
22.9%
(15.0%, 32.6%)
87.5%
(61.7%, 98.4%)
Note: 1. Floor, window sill, and window well samples were collected as dust wipes, soil was collected as
a core sample, and XRF measurements were taken for paint.
2. See Table 5-4 for definitions of sampling protocols B-1, B-2, and B-3.
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February 15. 1999 65
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Table 6-11. Sampling Protocol B: Assessment of the Impact of Various Methods of
Characterizing Dust Wipe Samples Obtained in a Full Risk Assessment, Using
the Proposed Rule Standards (XRF Paint Samples from Surfaces With > 5%
Deteriorated Paint).
# Homes included in analysis
% of Homes Failing the Risk Assessment
(# Homes Failing / # Homes)
% of Blood Samples 2 TO //g/dL
Sampling Protocol Group B
B-1
(Geometric Mean)
112
73.2%
B-2
(Arithmetic Mean)
112
75.9%
B-3
(Maximum Value)
112
79.5%
21.4%
% of Homes Failing the Risk Assessment on Media Standards te Media Standard)
(# of Homes Failing/* Homes in which samples were collected)
All Floors
Carpeted Floors Only
Uncarpeted Floors Only
Window Sill
Window Well
Soil (Average of average dripline
and average play area)
Dripline Soil Only
Play Area Soil Only
Paint (> 5% deteriorated)
5.4% (6/1 12)
2.9% (3/102)
3.7% (4/109)
28.6% (32/1 12)
8.9% (10/1 12)
2.9% (3/1 02)
7.3% (8/109)
32.1% (36/1 12)
19.6% (22/1 12)
4.9% (5/102)
16.5% (18/109)
49.1% (55/1 12)
NA
27.6% (29/105)
27.6% (29/105)
27.6% (29/105)
NA
NA
77.3% (68/88)
77.3% (68/88)
77.3% (68/88)
Performance Characteristics
Sensitivity
(LCB, UCB)
Specificity
(LCB. UCB)
Positive Predictive Value
(LCB, UCB)
Negative Predictive Value
(LCB, UCB)
87.5%
(67.6%, 97.3%)
30.7%
(21.3%. 41.4%)
25.6%
(16.6%, 36.4%)
90.0%
(73.5%, 97.9%)
91.7%
(73.0%, 99.0%)
28.4%
(19.3%. 39.0%)
25.9%
(17.0%, 36.5%)
92.6%
(75.7%, 99.1%)
91.7%
(73.0%, 99.0%)
23.9%
(15.4%, 34.1%)
24.7%
(16.2%, 35.0%)
91.3%
(72.0%, 98.9%)
Note: 1. Floor, window sill, and window well samples were collected as dust wipes, soil was collected as a
core sample, and XRF measurements were taken for paint. Window well samples are not included
in the Proposed Rule sampling scheme.
2. See Table 5-4 for definitions of sampling protocols B-1, B-2, and B-3.
3 NA indicates that these samples were not included in the analysis.
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February 15, 1999 66
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Under the Interim Guidance standards the maximum value had the highest sensitivity and
NPV, 91.7% and 87.5%, respectively, and the lowest specificity at 15.9%, while the geometric
mean was lowest at 83.3% and 84.0% for the sensitivity and NPV, respectively. Under the
Proposed Rule, the arithmetic mean and maximum value had the highest sensitivity at 91.7% and
the arithmetic mean had the highest NPV at 92.6%. The geometric mean had the lowest
sensitivity and NPV at 87.5% and 90.0%, respectively. Overall, the performance characteristics
indicate that there were not large differences in the performance characteristics between any of
the three statistics. Tables G-14 and G-15 present similar summaries when XRF measurements
are taken on surfaces with >15% deteriorated paint.
Again, since the focus of this analysis was on the effect the various summary methods
used have on characterizing the dust levels in the home, the performance characteristics were
calculated excluding the soil and paint samples from the analysis. Table 6-12 presents a
summary of the results and Tables G-16 and G-17 present the details of the analysis.
Table 6-12. Sampling Protocol B: Assessment of the Impact of Various Methods of
Characterizing Dust Wipe Samples Obtained in a Full Risk Assessment, Using
the Interim Guidance and Proposed Rule Standards (No Soil and Paint
Sampling).
U Homes included in analysis
% of Homes Failing the Risk
Assessment
Performance Characteristics
Sensitivity
Specificity
Positive Predictive Value
Negative Predictive Value
Sampling Protocol Group B
Interim Guidance
B-1
(Geometric
Mean)
B-2
(Arithmetic
Meanf
B-3
(Maximum
Value)
Proposed Rule
B-1
(Geometric
Mean)
B-2
(Arithmetic
Mean)
B-3
(Maximum
Value)
112
67.9%
75.9%
70.8%
33.0%
22.4%
80.6%
79.2%
25.0%
22.4%
81.5%
83.0% 31.3%
91.7%
19.3%
23.7%
89.5%
54.2%
75.0%
37.1%
85.7%
35.7%
62.5%
71.6%
37.5%
87.5%
57.1%
75.0%
47.7%
28.1%
87.5%
Note: See Table 5-4 for definitions of sampling protocols B-1, B-2, and B-3.
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February 15, 1999 67
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n
When performance characteristics are based only on the dust samples, differences in
performance characteristics are more pronounced. Under the Interim Guidance, the sensitivity
increases from 79.2% to 91.7% when using the maximum value rather than the arithmetic mean
and NPV increases from 81.5% to 89.5%. Under the Proposed Rule, the failure rate increases
from 35.7% to 57.1% when using the maximum value rather than the arithmetic mean and the
sensitivity increases from 62.5% to 75%.
Note that the differences observed in the home failure rates and the performance
characteristics for the two sets of standards will be discussed below.
V 6.1.2.3 Results of Protocol C Analysis: Comparison of Full Risk Assessment Outcome
to a Lead Hazard Screen Outcome
The Protocol C analysis compared the outcome of a risk assessment to the outcome of a
lead hazard screen. The lead hazard screen is meant to be a lower-cost assessment for well-
maintained homes constructed after 1960 or homes considered unlikely to have significant lead
paint, dust, or soil hazards. The lead hazard screen requires fewer environmental samples be
taken (i.e., soil is not sampled as it is in a risk assessment, and a choice of window components
sampled is allowed) while applying more stringent standards for passage of the assessment (i.e.,
half the Interim Guidance or Proposed Rule standards, whichever set of standards the assessment
is being performed under). Because fewer samples are required, the chances of passing a home
when a hazard exists may be higher than if a full risk assessment were performed. Note that for a
lead hazard screen, Section 402 only prescribes that "windows" be sampled. The 1995 HUD
Guidelines interpreted "windows" as sampling only the window wells and not the window sills.
The Section 403 Interim Guidance and Proposed Rule do not make an interpretation, but the
Proposed Rule does not provide a standard for window well sampling. Therefore, if a risk
^•%. *
assessor combines the HUD Guideline interpretation of the lead hazard screen with the Proposed
Rule standards thejwvill not sample any windows.JKot sampling any windows forces the lead
hazard screen to be based solely on floor dust and paint. Tables 6-13 and 6-14 assess the various
choices a risk assessor could make when performing a lead hazard screen.
Draft Report - Do Not Quote, Cite, Copy or Distribute February 15,1999
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Table 6-13. Sampling Protocol C: Comparison of Full Risk Assessment Outcome to,
Several Lead Hazard Screen Outcomes, Using the Interim Guidance Standards
(XRF Paint Samples From Surfaces With > 5% Deteriorated Paint).
9 Homes included in analysis
% of Homes Failing the Risk Assessment
(tt Homes Failing / ff Homes)
% of Blood Samples 2 10//g/dL
Sampling Protocol Group C
C-1
(Risk
Assessment)
112
85.7%
C-2
(Lead Hazard Screen
112
83.9%
112
83.9%
112
83.9%
21.4%
% of Homes Failing the Risk Assessment on Media Standards
(ft of Homes Failing/0 Homes in which samples were collected)
All Floors
Carpeted Floors Only
Uncarpeted Floors Only
Window Sill
Window Well
Soil
Dripline Soil Only
Play Area Soil Only
Paint (> 5% deteriorated)
Performance Characteristics
Sensitivity
(LCB, UCB)
Specificity
(LCB, UCB)
Positive Predictive Value
(LCB, UCB)
Negative Predictive Value
(LCB, UCB)
8.0% (9/1 12)
3.9% (4/102)
5.5% (6/102)
27.7% (31/1 12)
83.0% (93/1 12)
7.6% (8/105)
7.7% (8/104)
0% (0/52)
77.3% (68/88)
91.7%
(73%, 99.0%)
15.9%
(9%, 25%)
22.9%
(15%, 33%)
87.5%
(62%, 98%)
8.9% (10/1 121
2.9% (3/102)
7.3% (8/109)
NA
82.1% (92/1 12)
NA
NA
NA
77.3% (68/88)
87.5%
(67%, 97%)
17.0%
(10%, 27%)
22.3%
(14%, 32%)
83.3%
(59%, 96%)
8.9% (10/1 12)
2.9% (3/102)
7.3% (8/109)
32.1% (36/1 12)
NA
NA
NA
NA
77.3% (68/88)
83.3%
(62%, 95%)
37.5%
(27%, 49%)
26.7%
(17%, 38%)
89.2%
(75%, 97%)
8.9% (10/1 12)
2.9% (3/102)
7.3% (8/109)
32.1% (36/1 12)
82.1% (92/1 12)
NA
NA
NA
77.3% (68/88)
91.7%
(73%, 99%)
19.3%
(12%, 29%)
23.7%
(16%, 34%)
89.5%
(67%, 99%)
Note: 1. Floor, window sill, and window well samples were collected as dust wipes, soil was collected as a
core sample, and XRF measurements were taken for paint.
2. See Table 5-4 for definitions of sampling protocols C-1 and C-2.
3. The darkly shaded boxes indicate that these samples were not included in the analysis.
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February 15, 1999 69
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Table 6-14. Sampling Protocol C: Comparison of Full Risk Assessment Outcome to
Several Lead Hazard Screen Outcomes, Using the Proposed Rule Standards
(XRF Paint Samples From Surfaces With > 5% Deteriorated Paint).
# Homes included in analysis
% of Homes Failing the Risk Assessment
(# Homes Failing / # Homes)
% of Blood Samples 2 10/yg/dL
Sampling Protocol Group C
C-1
(Risk Assessment)
112
75.9%
C-2
(Lead Hazard Screen)
112
67.0%
112
67.0%
21.4%
% of Homes Failing the Risk Assessment on Media Standards
(# of Homes Failing/I Homes in which samples were collected)
All Floors
Carpeted Floors Only
Uncarpeted Floors Only
Window Sill
Window Well
Soil (Average of average dripline
and average play area)
Dripline Soil Only
Play Area Soil Only
Paint (> 5% deteriorated)
8.9% (10/1 12)
2.9% (3/102)
7.3% (8/109)
32.1% (36/1 12)
NA
27.6% (29/105)
NA
NA
77.3% (68/88)
30.4% (34/1 12)
10.8% (11/102)
26.6% (29/109)
NA
NA
NA
NA
NA
77.3% (68/88)
Performance Characteristics
Sensitivity
(LCB. UCB)
Specificity
(LCB, UCB)
Positive Predictive Value
(LCB, UCB)
Negative Predictive Value
(LCB UCB)
91.7%
(73%, 99%)
28.4%
(19%, 39%)
25.9%
(17%. 37%)
92.6%
(76%, 99%)
83.3%
(63%, 95%)
37.5%
(27%, 49%)
26.7%
(17%. 38%)
89.2%
(75%, 97%)
30.4% (34/1 12)
10.8% (11/102)
26.6% (29/109)
64.3% (72/1 12)
NA
NA
NA
NA
77.3% (68/88)
91.7%
(73%, 99%)
25.0%
(16%, 35%)
25.0%
(16%, 35%)
91.7%
(73%, 99%)
Note: 1. Floor, window sill, and window well samples were collected as dust wipes, soil was collected as a
core sample, and XRF measurements were taken for paint.
2. See Table 5-4 for definitions of sampling protocols C-1 and C-2.
3. The darkly shaded boxes indicate that these samples were not included in the analysis.
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February 15, 1999 70
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Note that most of the homes in the Rochester Study would not have been recommended for
a hazard screen since more than 80% of the homes were built prior to 1940 and an additional 5%
were built prior to 1970. This should be taken into account when interpreting the results in
Tables 6-13,6-14, and G-23 which present the performance characteristics for a risk assessment
and lead hazard screen, calculated under the Interim Guidance and Proposed Rule standards,
respectively, when XRF measurements were taken from surfaces with greater than 5%
deteriorated paint and different window components were sampled.
As shown in Table 6-13, under the Interim Guidance standards, a risk assessment attains
an sensitivity of 91.7% and an NPV of 87.5%. A lead hazard screen 1) sampling window wells
attained sensitivity of 87.5% and an NPV of 83.3%, 2) sampling window sills attained a
sensitivity of 83.3% and an NPV of 89.2%, and 3) sampling window sills and window wells a
sensitivity of 91.7% and an NPV of 89.5%. Under the Proposed Rule, as shown in Table 6-14,
the risk assessment attains a sensitivity of 91.7% and an NPV of 92.6%. The lead hazard screen
based on window sills had a sensitivity of 91.7% and an NPV of 91.7% and based on no window
samples had a sensitivity of 83.3% and an NPV of 89.2%.
Table G-23 in Appendix G compares the performance characteristics for a lead hazard
screen performed under the Interim Guidance sampling window wells to a lead hazard screen
performed under the Proposed Rules sampling window sills.
6.1.2.4 Comparison of the Performance Characteristics under the Interim Guidance
Standards and the Proposed Rule Standards
Differences between the Proposed Rule and the Interim Guidance were described in detail
in Section 1.0. Changes in the performance characteristics will be driven by four primary
factors:
1. lower dust standards associated with the Proposed Rule,
2. lower soil standards associated with the Proposed Rule,
3. exclusion of window well sampling in the proposed Rule, and
4. the use of the arithmetic mean in the Proposed Rule to characterize dust and
soil lead levels.
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Each of these can have a different and sometimes conflicting effect. For example, lower soil
standards under the Proposed Rule would increase failure rates while use of the arithmetic mean
under the Proposed Rule may decrease failure rates.
The purpose of this analysis is to both assess how all changes in the Proposed Rule act
jointly to affect the performance characteristics as well as to discuss the expected effect of the
individual changes.
As discussed above, fewer homes failed when the Proposed Standards were used rather
than the Interim Guidance. Sensitivity and NPV remained high, and specificity and PPV
increase with the use of the Proposed Rule. Therefore, overall, the Proposed Rule appears to
offer an improvement over the Interim Guidance by maintaining the probability of correctly
failing a home while reducing the probability of incorrectly failing a home.
Lower Dust-Lead and Soil-Lead Standards
To assess the effect that lower dust and soil standards have on the performance
characteristics, consider Table 6-15 which shows the performance characteristics when the
arithmetic mean and maximum value are used to characterize the soil-lead concentrations and the
floor-dust and window sill dust-lead loadings under the Interim Guidance and Proposed Rule
standards. The details of the performance characteristics are provided in Tables G-20 and G-21
for the Interim Guidance and Proposed Rule standards, respectively.
Table 6-15 shows that, for the Rochester Study data, the lower standards fail more homes
but increase sensitivity and NPV, while specificity decreases. Consider the first two columns
where the arithmetic mean is used to characterize the floor dust, window sill dust, and soil lead
levels. Under the Proposed Rule, 52.7% percent of the homes fail standards with 32.1% of the
homes failing on the window sills and 27.6% failing on the soil standards. The sensitivity and
NPV are high at 87.5% and 94.3%, respectively. Under the Interim Guidance, 29.5% of the
homes fail with 22.3% of the homes failing on window sills and only 7.6% of the homes failing
on soil. The sensitivity and NPV of 45.8% and 83.5%, respectively, are lower than the Proposed
Rule. Similar results are observed when the maximum value is used to characterize the floor,
window sill, and soil lead levels under the two sets of standards.
Draft Report - Do Not Quote, Cite, Copy or Distribute February 15. 1999 72
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Table 6-15. Summary of the Assessment of Lowered Soil and Dust Standards Associated
with the Proposed Rule Relative to the Interim Guidance.
tt Homes included in analysis
% of Homes Failing the Risk Assessment
(# Homes Failing / # Homes)
the Arithmetic Mean
Interim
Guidance
Proposed Rule
the Maximum Value
Interim
Guidance
112
29.5%
52.7% II 36.6%
II
% of Homes Failing the Risk Assessment on Media Standards
(# of Homes Failing/* Homes in which samples were collected)
All Floors
Carpeted Floors Only
Uncarpeted Floors Only
Window Sill
Window Well
Soil (Average of average
dripline and average play
area)
Dripline Soil Only
Play Area Soil Only
Paint
3.6%
1.0%
2.8%
22.3%
NA
7.6%
7.7%
0.0%
NA
8.9%
2.9%
7.3%
32.1%
NA
27.6%
NA
NA
NA
8.0%
3.9%
5.5%
27.7%
NA
7.6%
7.7%
0.0%
NA
Performance Characteristics
Sensitivity
Specificity
Positive Predictive Value
Neaative Predictive Value
45.8%
75.0%
33.3%
83.5%
87.5%
56.8%
35.6%
94.3%
58.3%
69.3%
34.1%
85.9%
Proposed Rule
67.0%
19.6%
4.9%
16.5%
49.1%
NA
27.6%
NA
NA
NA
87.5%
38.6%
28.0%
91.9%
Note: 1. Floor, window sill, and window well samples were collected as dust wipes, soil was collected as a
core sample. Window well samples are not included in the Proposed Rule sampling scheme.
2. NA indicates that these samples were not included in the analysis.
3. See Tables G-20 and G-21 in Appendix G for the details behind the calculations of the
percentages.
Exclusion of Window Well Sampling
The Proposed Rule does not include a standard for lead in window well dust. To
understand the impact that not sampling dust from window wells may have on the outcome of a
risk assessment, consider Table 6-16, which presents performance characteristics for 1) the
Interim Guidance standards including only floor, window sill, and window well dust-lead and
soil-lead samples and 2) the Proposed Rule standards including only floor and window sill dust-
lead and soil-lead samples. The details of the performance characteristics are presented in Tables
G-21 and G-22 for the Proposed Rule and Interim Guidance standards, respectively.
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February 15, 1999 73
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Table 6-16. Summary of the Assessment of the Exclusion of Window Well Sampling
Under the Proposed Rule Relative to the Interim Guidance.
# Homes included in analysis
% of Homes Failing the Risk Assessment
(# Homes Failing / # Homes)
Lead in Dust Characterized by
the Arithmetic Mean
Interim
Guidance
Proposed Rule
Lead in Dust Characterized by
the Maximum Value
Interim
Guidance
112
77.7%
52.7% | 83.9%
% of Homes Failing the Risk Assessment on Media Standards
(# of Homes Failing/0 Homes in which samples were collected)
All Floors
Carpeted Floors Only
Uncarpeted Floors Only
Window Sill
Window Well
Soil (Average of average dripline
and average play area)
Dripline Soil Only
Play Area Soil Only
Paint (> 5% deteriorated)
3.6%
1.0%
2.8%
22.3%
75.9%
7.6%
7.7%
0.0%
NA
8.9%
2.9%
7.3%
32.1%
NA
27.6%
NA
NA
NA
Sensitivity
Specificity
Positive Predictive Value
83.3%
23.9%
23.0%
84.0%
87.5%
56.8%
35.6%
94.3%
8.0%
3.9%
5.5%
27.7%
83.0%
7.6%
7.7%
0.0%
NA
91.7%
18.2%
23.4%
88.9%
Proposed Rule
67.0%
19.6%
4.9%
16.5%
49.1%
NA
27.6%
NA
NA
NA
87.5%
38.6%
28.0%
91.9%
Note: 1. Floor, window sill, and window well samples were collected as dust wipes, soil was collected as a
core sample. Window well samples are not included in the Proposed Rule sampling scheme.
2. NA indicates that these samples were not included in the analysis.
3. See Tables G-21 and G-22 in Appendix G for the details behind the calculation of the percentages.
Comparing Table 6-15 to 6-16 shows that when the window well samples are included in
the testing, more homes fail under the Interim Guidance, even though the standards were lowered
in the Proposed Rule. When either the arithmetic mean or maximum value are used to
characterize the dust levels, the window well samples drive the home failures. For example,
when the maximum value is used to characterize the dust samples, 83.9% of the homes fail the
testing under the Interim Guidance, with 83% of the homes failing due to window wells. While
failure rates are higher under the Interim Guidance, the Proposed Rule has higher sensitivity
and NPV when using the arithmetic mean and higher NPV when using the maximum value
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 74
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(Table 6-16). This indicates that, when using the Rochester Study data and with the lower
standards in the Proposed Rule, the removal of the window well samples from the assessment
does not affect the ability of the assessment to detect health hazards. The inclusion of the
window wells appears to fail homes unnecessarily.
The exclusion of the window well dust samples impacts the outcome of the lead hazard
screen. The Section 402 protocols recommend that dust samples be collected from floors and
window wells during a lead hazard screen. Therefore, under the Proposed Rule, dust samples
may be taken only from the floor during a lead hazard screen. As shown in Table 6-14, the lead
hazard screen is not as discriminating when based only on floor-dust and paint samples.
Use of the Arithmetic Mean to Characterize Dust-Lead Loadings and Soil-Lead
Concentrations
Currently the Interim Guidance recommends that the maximum of the floor-dust, window
sill-dust, window well-dust, and soil sample results be compared to the respective standards. If
any one sample result is greater than the standard, then the home fails. The Proposed Rule
recommends that the arithmetic mean of the floor-dust, window sill-dust, and soil sample results
be compared to the respective revised standards. If the arithmetic average of any one
media/component is greater than its respective standard, then the home fails. To understand the
effect these summary methods may have, consider Table 6-15 again.
As discussed earlier, for both sets of standards, fewer homes fail when the arithmetic
mean is used to characterize the dust levels than when the maximum value is used. Under the
Interim Guidance standards, the sensitivity, PPV, and NPV are higher for the maximum value
than for the arithmetic mean. Under the Proposed Rule, the specificity, PPV, and NPV are
higher using the arithmetic mean, and the sensitivity is the same regardless of the summary
method. Therefore, under the Proposed Rule standards, the arithmetic mean provides better
performance characteristics than the maximum value.
Table 6-17 below presents an overall summary of the performance characteristics
calculated for a full risk assessment performed under the Interim Guidance and Proposed Rule.
The details of the table were provided in Tables 6-10 and 6-11 presented earlier. Overall, Table
6-17 shows that under the Proposed Rule, the combination of the arithmetic mean, lower media
Draft Report - Do Not Quote, Cite, Copy or Distribute February 15, 1999 75
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Table 6-17. Summary of the Comparison of the Interim Guidance Results and Proposed
Rule Results for a Full Risk Assessment.
# Homes included in analysis
% of Homes Failing the Risk Assessment
(# Homes Failing / # Homes)
Interim Guidance*
Proposed Rule"
112
85.7%
75.9%
% of Homes Failing the Risk Assessment on Media Standards
(# of Homes Failing/if Homes in which samples were collected)
Floors
Carpeted Floors Only
Uncarpeted Floors Only
Window Sill
Window Well
Soil (Average of average dripline and
average play area)
Dripline Soil Only
Play Area Soil Only
Paint (> 5% deteriorated)
8.0%
3.9%
5.5%
27.7%
83.0%
7.6%
7.7%
0.0%
77.3%
8.9%
2.9%
7.3%
32.1%
NA
27.6%
NA
NA
77.3%
Performance Characteristics
Sensitivity
Specificity
Positive Predictive Value
Negative Predictive Value
91.7%
15.9%
22.9%
87.5%
91.7%
28.4%
25.9%
92.6%
8 The maximum value of the floor, window sill, and window well dust and soil samples were compared to
the respective standard.
b The arithmetic mean of the floor, window sill, and window well dust and soil samples were compared to
the respective standard.
Note: 1. Floor, window sill, and window well samples were collected as dust wipes, soil was collected as a
core sample, and XRF measurements were taken for paint. Window well samples are not included
in the Proposed Rule sampling scheme.
2. NA indicates that these samples were not included in the analysis.
3. See Tables 6-10 and 6-11 for the details behind the calculations of the percentages.
standards, and the removal of the window wells from the sampling protocol results in an
assessment that fails fewer homes unnecessarily, yet maintains the ability to identify health
hazards.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 76
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6.1.2.5 Estimated Costs of Performing a Risk Assessment and a Lead Hazard Screen
Using the risk assessment and lead hazard screen cost estimates discussed earlier,
estimated costs of risk assessments and lead hazard screens under Protocol A and Protocol C are
presented below. Note that Protocol B assesses the effect of different dust summary measures on
the outcome of a risk assessment. The number of samples taken are the same as Protocol A-l.
Therefore, the estimated cost for Protocol B is the same as the estimated cost for A-l.
Protocol A assessed the effect of sampling dust from additional rooms on the outcome of
a risk assessment. Table 6-18 presents the cost estimates of the risk assessment when the number
of rooms in which dust samples are obtained increases from 2 to 4 (i.e., number of dust samples
increases from 6 to 8).
Table 6-18. Sampling Protocol A: Comparison of the Estimated Costs of a Full Risk
Assessment when Dust Samples are Taken in Two. Three, and Four Rooms.
Sampling Protocol Group A
A-1 (4 Rooms)
8-9
A-2 (3 Rooms)
7
$584.11
$814.00
$561.50
$814.00
A-3 (2 Rooms)
6
$547.50
$814.00
Note: 1. Floor, window sill, and window well samples were collected as dust wipes, soil was collected as a
core sample, and XRF measurements were taken for paint.
2. See Table 5-3 for definitions of sampling protocols A-1, A-2, and A-3.
If a basic fee were charged for the risk assessment, the estimated costs of the assessments
vary slightly depending on the number of rooms (i.e., number of dust samples) obtained. The
basic fee estimated costs ranged from $547.50 for a risk assessment that had 6 dust samples
taken to $584.11 when up to 8 dust samples were taken. If separate fees were charged for the
visual assessment, environmental sampling, and risk assessment report, the estimated cost of the
assessment remained the same no matter how many rooms were sampled for dust (i.e., dust
samples taken).
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 77
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One of the advantages of the lead hazard screen is the reduction in the number of samples
which implies a cost savings for the assessment. Table 6-19 presents the estimated costs for a
full risk assessment and lead hazard screen when a basic fee is charged for the assessment and
separate fees are charged the different components of the assessment/screening.
Table 6-19. Sampling Protocol C: Comparison of the Estimated Cost of a Full Risk
Assessment Outcome to the Cost of a Lead Hazard Screen Outcome.
Sampling Protocol Group C
C-1
(Risk Assessment)
Estimated Costs of Activity
Basic Fee
Separate Fee
$584.11
$814.00
C-2
(Lead Hazard Screen)
$126.00
$575.25
Note: 1. Floor, window sill, and window well samples were collected as dust wipes, soil was collected as
core sample, and XRF measurements were taken for paint.
2. See Table 5-4 for definitions of sampling protocols C-1 and C-2.
As expected, the estimated costs of a lead hazard screen were less than that for a risk
assessment. Under protocol C, when a basic fee was charged, the lead hazard screen cost
$126.00 while a risk assessment cost $547.50. If separate fees were charged for the visual
assessment, the environmental sampling, and the report, the lead hazard screen was estimated to
cost $575.25 and the risk assessment to cost $814.00.
6.2 OBJECTIVE 2: ASSESSMENT OF ESTIMATORS OF THE TRUE AVERAGE LEAD
LEVELS AND SAMPLING PROTOCOLS USING ERROR PROBABILITIES
The ability of three statistics - geometric mean, arithmetic mean, and maximum value - to
estimate the unobservable, "true" average dust and soil levels in a single home was assessed in
this analysis.
As discussed in Section 5.2, the Rochester Lead-in-Dust Study data, the Rhode Island
Department of Health data, and the CAP Study data were used to calculate the variance
components needed to calculate the geometric mean, arithmetic mean, and maximum value error
probabilities. Section 4 and Section 5.2 provide details on the data as well as the variance
component and error probability calculations.
Draft Report - Do Not Quote, Cite, Copy or Distribute February 15. 1999 78
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Presented below is
1. A discussion of the within-house variance components,
2. A comparison of the geometric mean, arithmetic mean, and maximum value error
probabilities for a risk assessment, a "compound" lead hazard screen, and a
"simple" lead hazard screen,
3. A discussion of the effect of the number of samples collected for floor dust, window
sill dust, window well dust, and soil on the error probabilities, and
4. A discussion of the effect the different media/component standards, Interim
Guidance and Proposed Rule, have on the different error probabilities.
6.2.1 Within-House Variance Components
Three sets of data were used to calculate within-house variance components needed for
the error probability calculations. The Rochester Study data were used to calculate within-house
components of variation for floor, window sill, and window well dust-wipe results, the CAP
Study data were used to calculate the within-house component of variation for soil results, and
the Rhode Island Department of Health data were used to calculate within-house components of
variation for all media/components. Table 6-20 presents the estimated within-house components
of variations for each set of data, media, and component. Because some of the estimates were
calculated in previous EPA work, the source from which the estimates were extracted is also
provided.
Table 6-20 shows that the floor and window sill dust within-house variances are similar
across the Rochester Study and Rhode Island Department of Health data, while the Rochester
window well variance component is nearly double the Rhode Island window well variance
component. The combined side of house/foundation soil component of variation for the Rhode
Island soil is larger than either the foundation or boundary soil variation seen for the CAP Study
data.
Draft Report - Do Not Quote, Cite, Copy or Distribute February 15, 1999 79
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Table 6-20. Estimated Within-House Components of Variation for Each Data Source,
Media, and Component.
Dfltd Source
Rochester
Study
CAP Study
Rhode Island
Depart-
ment of
Health
Data
Media
Dust
Soil
Dust
Soil
Dust Component/
Soil Location
Floor
Window Sill
Window Well
Foundations
Boundaries
Floor
Window Sill
Window Well
Side of House/
Foundations
Within-House
Variance (o,1)
0.848
1.304
3.273
0.602
0.239
0.708
1.617
1.758
1.034
Source of Variance
Component Value
Draft Final EPA report,
"Components of Variation of
Lead in Household Dust,
Soil, and Paint "[18]
New mixed
model analysis
(Section 5.2)
6.2.2 Effect of the Use of the Geometric Mean, Arithmetic Mean, and Maximum Value on
the Error Probabilities
Two sets of analyses were conducted to evaluate the effect of the different estimators on
determining a lead hazard as characterized by the error probabilities. The first set of analyses
assess the effect of the estimators when a risk assessment and "compound" lead hazard screen are
conducted, while the second set evaluates the effect when a "simple" lead hazard screen is
conducted. The definitions of "simple" and "compound" lead hazard screens are provided in
Section 5.2.
6.2.2.1 Risk Assessment and "Compound" Lead Hazard Screen
Using the within-house variabilities listed in Table 6-20 and the calculations discussed in
Section 5.2, the error probabilities for performing a risk assessment and a "compound" lead
hazard screen, when each media/component is evaluated separately, were calculated for the
geometric mean, arithmetic mean, and maximum value and when 2,3, or 4 samples were
collected for floor-dust, window sill-dust, window well-dust, and soil. Figures 6-6 and 6-7
present the results for dust and soil, respectively, when two samples are collected, the error
probabilities are calculated under the Interim Guidance standards, and the within-house variation
from the Rochester Study and CAP Study data are used. Figures 6-8 and 6-9 present the same
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 80
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results when using the within-house variation from the Rhode Island Department of Health data.
Tables 6-21 through 6-24 present the actual Type I and Type II error probabilities for the floor
dust, window sill dust, window well dust, and soil, respectively, when 2,3, and 4 samples are
collected; the assumed "true" house media/component lead levels are assumed to be one-half the
Interim Guidance standard, at the standard, and double the standard; and the Rochester Study and
CAP Study variances are used. Tables H-l through H-4 present similar results when the Rhode
Island Department of Health data are used to calculate the within-house variance components.
In Figure 6-6 through 6-9, the solid vertical line in each graph represents the media
standard for which passage or failure of the home is determined. For instance, under the Interim
Guidance and a risk assessment the dust standards are: 100 ug/ft2 for floors, 500 ug/ft2 for
window sills, and 800 ug/ft2 for window wells. For a lead hazard screen under the Interim
Guidance, the dust standards are: 50 ug/ft2 for floors, 250 ug/ft2 for window sills, and 400 ug/ft2
for window wells (i.e., half the standards used for the risk assessment). To the left of the solid
vertical line are the Type I error probabilities (i.e., incorrectly failing a house) and to the right are
the Type II error probabilities (i.e., incorrectly passing a house). The x-axis is the assumed
"true" house average lead level for a given medium and component, and the y-axis is the error
probability.
As the assumed "true" average lead level moves further from the standard of comparison,
the Type I and Type H error probabilities, for all three statistics, approach zero. The geometric
mean always produces the lowest Type I error probabilities, while the maximum value produces
the highest Type I error probabilities. The reverse is true for Type E errors. The error
probabilities for the arithmetic mean always lie somewhere between that for the maximum value
and the geometric mean. These observations hold true for all media/components.
Tables 6-21 through 6-24 and H-l through H-4, in combination with Figures 6-6 through
6-9, show the following results:
Draft Report - Do Not Quota, Cite, Copy or Distribute February 15. 1999 81
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Error Prob.bUitj vnr • braf* of Truo Condition!
Oik* Floor. Ou.1 fc-k A "
« ) an Floorw
Error PratMttilitr ow • R-n.j« ol Tru* CowUtioai
Vmiaf Hoon Dtut L»«d H.»rd Scr««n SUivdnnl
U 40 to BO 100 120 1*0 IN ISO tOO
Tni« HOUM Cmmttric M.in Ditft Uod LMdlnl (u(/rt2) OB Floon
Error Probability
U«U« Window SU1*
ga ol Tru« CoadlUoQJ
k 4jio.im.nl 9Ua4kn!
100 !00 KC 400 500 »00 TOO 100
Truo HOUM Ceomolric HMD Dual Uod LradiDI (ut/(t2) on Window 5dli
trror Prob-bUllj or.r • lHoj. of rn>« CondlUon.
Urin| window 3111. Dun U*d H«urd Scroon st*nd*rd
(Tn SompUi)
Tnjo HOUM CwOmoUIC Uoui Dun Lood Loidlni (ui/tt2) an Window Sill.
Brror Probobilllj o»wr • lUnjo o[ Truo Condition.
Urlu Window WoUl Irujt Rl*k AMMnnont SUndord
200 400 NO KM 1000 1200 HM UOO
Tru. »>».. 0—TOlrlo kUu Duwt U.d Looxlin4 (u(/U) on Tmaow W.1U
Error ProbobUllj owtr • Ron|o ol Tnjo Condition.
u.lnf window *.ll. Du.l Load H*Mrd Scrowo 3und>rd
200 WO WO «00 1000 1200 1«00
Tru. HOUM Coom.trtc llou Dull U.d Lo.dln. (ui/flZ) oo Window 1.11.
Figure 6-6. Comparison of Risk Assessment and "Compound" Lead Hazard Screen
Geometric Mean, Arithmetic Mean, and Maximum Value Error Probabilities for
Two Floor. Window Sill, and Window Well Dust Samples using the Interim
Guidance Standards - Variance Components from the Rochester Lead-in-Dust
Study Homes.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 82
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brv Probability ow • bng* «f Tnw C*adlUou
U*im SoU SUndtrd. 5000 pp ro
(Tro Foundation 9oU S»mpl»i)
1000 2000 3000 4000 6000 1000 7000 5000 HOO
HOUM CMOWITM HMD Soil U«d Cencmtr.tioo (ppm) on Found-lion
Error PnbabUltj orw * JUn|* •! Tnw CondlUoni
Urini SoU 3Und*rd. MOO ppm
(T»o BoundftrtM 9
1000 £000 3000 4000 5000 WOO 7000 9000
HOUM C*om.Lric U«u Soil L.. MMB Soil U«d C.nc«ntr.Uoo (ppm) an Found.Uoa
Error Prob«blLtr orw • ba|« ol Tni«
Orin| Sail SUndud. 5000 ppm
(Thi-M BouadAriM Sail S«n>pl«)
3000 4000 8000 BOOO TOGO BOOO
nMtrie M«u Soil U.d ConeatnUan (ppm) OB B
Error Probabiiitr a*«r * JUnf« of T
Uiln* SoU SUndtrd. MOO
(four FouiuUUan SoU
1000 3000 4000 BOOO HOO TOGO BOOO MOO
few. C*om*trie UMH SoU L*.d C«ot«,lr.lion (ppm) on Found.tion
Error Prob.bdily onr • Run. »l Tnw Caaditiaa*
Uiinj SoU SUndArd. MOO ppm
(Four BoundartM 3aU S
Figure 6-7. Comparison of Risk Assessment Geometric Mean, Arithmetic Mean, and
Maximum Value Error Probabilities for Two, Three, and Four Soil Samples
Collected, Using the Interim Guidance Standards - Variance Components
from the Foundation of the Home and Boundary of the Property in the CAP
Study Data.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 83
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Utlai Vlnito* Villi Duit RUk AfMMOunt SUoiUrd
400 BOO BOO 1000 1200 1400
1.0
OB
1.0
OS
80 BO 100 120
« 0«>m«lrlc W.ui Ou«l Uwl
Error ProtMbU.tr onr • Ru|* of Tru« C
« 3Uli D
ZOO 300 400 SOO BOO
TTIM HOUM Geometric Uau Diut U*d UwJlnj (uj/fU) on •
O 1000 1200 1*
d U«Uni (ui/IU) on Window *.U.
Figure 6-8 Comparison of Risk Assessment and "Compound" Lead Hazard Screen
Geometric Mean, Arithmetic Mean, and Maximum Value Error Probabilities for
Two Floor. Window Sill, and Window Well Dust Samples Using the Interim
Guidance Standards - Variance Components from the Rhode Island
Department of Health Homes.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 84
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Uilng Soil Standard. BOOO ppm
(Two Foundation Soil S«mpl«*)
l.O •
0.9-
0.8 -
O.T -
0-6 •
0.0 •
0.4
0.3
0.2
0.1
O.O
E»llir\»lor»7
1000 BOOO 3000 4000 6OOO 6OOO 7OOO 8OOO BOOO IOOOO
Error Probability ovmr * R«n«« of Tru« Condition*
Ualng Soil Standard, OOOO ppm
(Tnr«« Foundation Soil Sampl«)
aooo 3000 4000 eooo oooo T-OOO eooo BOOO 10000
(Four Found
ondard, BOOO ppm
itlon Soil Sarnpl**)
1OOO 2OOO 3OOO 4000 OOOO 6OOO TOOO BOOO BOOO IOOOO
Figure 6-9. Comparison of Risk Assessment Geometric Mean, Arithmetic Mean, and
Maximum Value Error Probabilities for Two, Three, and Four Soil Samples
Collected from Side of the House/Foundation for Homes Using the Interim
Guidance Standards - Variance Components from the Rhode Island
Department of Health Data.
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February 15, 1999 85
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Table 6-21. Comparison of Risk Assessment and "Compound" Lead Hazard Screen Error
Probabilities for Each Statistic Over a Range of Assumed "True" House Lead
Levels For Two. Three, and Four Floor Dust Samples Using the Interim
Guidance Standards1 - Variance Components from the Rochester Study Data.
:====
Assessment
================
'Compound*
Lead Hazard
Screen
Risk Assessment
==
Number
of
Samples
2
3
4
2
3
4
=====
Assumed
•True-
House Floor
Lead
Loading
tog/ft')
50
100
200
50
100
200
50
100
200
50
100
200
50
100
200
50
100
200
===========================
Error Probability of the Statistic
Type 1 Error
Arithmetic
Mean
=====
0.140
0.530
0.150
0.623
0.150
0.712
0.237
0.598
0.231
0.660
0.206
0.730
'
Geometric
Mean
0.072
0.428
.
0.048
0.452
0.033
0.467
.
0.144
0.500
.
0.096
0.500
m
0.066
0.500
Maximum
Value
=====
0.300
0.712
.
0.469
0.865
0.601
0.935
.
0.401
0.750
.
0.536
0.875
.
0.641
0.938
•
Type II Error
Arithmetic
Mean
=====
0.465
0.120
0.355
0.059
.
0.339
0.025
.
0.404
0.113
.
0.326
0.056
.
0.316
0.024
Geometric
Mean
.
0.572
0.158
•
0.548
0.100
•
0.533
0.067
•
0.500
0.144
.
0.500
0.096
.
0.500
0.066
=====
Maximum
Value
.
0.288
0.055
•
0.135
0.012
•
0.065
0.003
•
0.250
0.051
•
0.125
0.012
•
0.063
0.003
===========1
1 The floor dust wipe standard at which a home fails the assessment was assumed to be 100 j/g/ft2 for
the risk assessment and 50 //g/ft1 for the lead hazard screen.
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February 15, 1999 86
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Table 6-22. Comparison of Risk Assessment Error Probabilities for Each Statistic Over a
Range of Assumed "True" House Lead Levels For Two. Three, and Four
Window Sill Dust Samples Using the Interim Guidance Standards1 - Variance
Components from the Rochester Study Data.
===
Assessment
'Compound*
Lead Hazard
Screen
Risk
Assessment
:=^==
Number
of
Samples
2
3
4
2
3
4
:^==^=
Assumed
•True" House
Window Sill
Lead Loading
(llQtft'l
250
500
1000
250
500
1000
250
500
1000
250
500
1.000
250
500
1.000
250
500
1 000
Error Probability of the Statistic
Type 1 Error
Arithmetic
Mean
0.182
0.530
.
0.214
0.629
.
0.255
0.736
.
0.304
0.610
.
0.316
0.681
.
0.335
0.763
Geometric
Mean
0.098
0.402
.
0.073
0.427
.
0.056
0.444
.
0.195
0.500
.
0.147
0.500
.
0.112
0.500
Maximum
Value
0.352
0.695
.
0.537
0.857
0.674
0.932
.
0.470
0.750
.
0.614
0.875
.
0.719
0.938
Type II Error
Arithmetic
Mean
.
0.475
0.157
.
0.350
0.086
.
0.319
0.039
.
0.392
0.131
.
0.303
0.076
.
0.288
0.036
Geometric
Mean
.
0.598
0.230
•
0.573
0.162
.
0.556
0.119
•
0.500
0.195
•
0.500
0.147
0.500
0.112
Maximum
Value
.
0.305
0.086
•
0.143
0.021
•
0.068
0.006
•
0.250
0.074
•
0.125
0.020
•
0.063
0.005
1 The window sill dust wipe standard at which a home fails the assessment was assumed to be 500
//g/ft2 for the risk assessment.
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February 15, 1999 87
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Table 6-23. Comparison of Risk Assessment and "Compound" Lead Hazard Screen Error
Probabilities for Each Statistic Over a Range of Assumed "True" House Lead
Levels For Two. Three, and Four Window Well Dust Samples Using the
Interim Guidance Standards1 - Variance Components from the Rochester
Study Data.
Assessment
'Compound*
Lead Hazard
Screen
Risk
Assessment
Number
of
Samples
2
3
4
2
3
4
Assumed
•True-
House
Window
Well Lead
Loading
(pg/ft')
400
800
1,600
400
800
1,600
400
800
1,600
400
BOO
1,600
400
800
1,600
400
800
1,600
Error Probability of the Statistic
Type I Error
Arithmetic
Mean
0.308
0.488
.
0.405
0.642
.
0.463
0.743
.
0.475
0.612
.
0.537
0.729
.
0.578
0.794
Geometric
Mean
0.147
0.353
.
0.127
0.373
.
0.111
0.389
.
0.294
0.500
.
0.253
0.500
.
0.222
0.500
•
Maximum
Value
0.434
0.658
.
0.636
0.837
.
0.771
0.923
.
0.579
0.750
.
0.726
0.875
.
0.822
0.938
•
Type II Error
Arithmetic
Mean
.
0.485
0.270
•
0.328
0.152
.
0.278
0.078
.
0.362
0.203
•
0.253
0.119
.
0.223
0.064
Geometric
Mean
•
0.647
0.392
•
0.627
0.322
•
0.611
0.271
•
0.500
0.294
•
0.500
0.253
•
0.500
0.222
Maximum
Value
•
0.342
0.166
•
0.163
0.054
•
0.077
0.018
•
0.250
0.123
•
0.125
0.043
•
0.063
0.015
1 The window well dust wipe standard at which a home fails the assessment was assumed to be 800
/yg/ft2 for the risk assessment and 400 jig/ft1 for the lead hazard screen.
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February 15, 1999 88
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Table 6-24. Comparison of Boundary and Foundation Two. Three, and Four Soil Sample
Error Probabilities for Each Statistic Over a Range of Assumed "True" House
Lead Levels Using the Interim Guidance Standards1 - Variance Components
from the CAP Study Data.
Location
Boundary of
Property
Foundation
Number of
Samples
2
3
4
2
3
4
Assumed
•True' House
Soil Lead
Concentration
(ppm)
2,500
5,000
7,500
2,500
5,000
7,500
2,500
5,000
7,500
2,500
5,000
7,500
2,500
5.000
7,500
2,500
5,000
7.500
Error Probability of the Statistic
Type 1 Error
Arithmetic
Mean
0.046
0.563
.
0.022
0.615
.
0.011
0.654
0.173
0.587
.
0.155
0.645
0.132
0.709
•
Geometric
Mean
0.022
0.500
0.007
0.500
0.002
0.500
.
0.103
0.500
.
0.061
0.500
.
0.037
0.500
•
Maximum
Value
0.150
0.750
.
0.217
0.875
.
0.278
0.938
.
0.337
0.750
.
0.460
0.875
.
0.561
0.938
•
Type II Error
Arhhmetic
Mean
.
0.432
0.094
.
0.399
0.057
.
0.396
0.026
.
0.416
0.187
.
0.346
0.128
.
0.342
0.061
Geometric
Mean
.
0.500
0.120
.
0.500
0.075
.
0.500
0.049
.
0.500
0.230
.
0.500
0.183
.
0.500
0.148
Maximum
Value
.
0.250
0.041
.
0.125
0.008
.
0.063
0.002
.
0.250
0.090
.
0.125
0.027
.
0.063
0.008
1 The soil standard at which a home fails the assessment was assumed to be 5,000 ppm.
1. Type I error rates were very high when using the maximum value. For example, as
shown in Tables 6-24 and H-2, for both the Rochester and Rhode Island variance
components, when four window sill samples were used in the error probability
calculations the maximum value errors remained above 0.500. This was true for
floors and window wells even when the "true" media lead loading was assumed to be
half the standard. Similar observations were made when four soil samples were taken
at the foundation of the home (see Tables 6-24 and H-4)
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2. Both Tvoe I and Type II error rates were high (usually over 0.250^ for all three
statistics when the "true" media lead level was assumed to be within 20% of the
standard. This is true for both the Rochester and Rhode Island data. For instance, as
shown in Figure 6-6, when two floor samples from a risk assessment were used in the
error probability calculations and the assumed "true" average floor dust-lead loading
was assumed to be 80 ug/ft2 the geometric mean, arithmetic mean, and maximum
value Type I error rates were 0.33,0.42, and 0.82, respectively. This implies that
there is a very large "gray" area around the standard with a high probability of a
"wrong" decision..
Which estimator is best may depend on which type of error is more "acceptable". If the
maximum value is used under the Interim Guidance, then more homes will fail the assessments
when the true house lead level is actually below the standard, but fewer homes will pass the
assessment when in fact the true lead level is above or equal to the standard. On the other hand,
if the geometric mean is used, then fewer homes will fail the assessment when the true house
lead level is below the standard, but more homes will pass the assessment when the true lead
level is above or equal to the standard. If the extreme differences in the Type I and Type n errors
seen with the geometric mean and maximum value cause concern, a compromise may be the
arithmetic mean. Note that the results presented are for the Interim Guidance. The effect of the
lower standards in the Proposed Rule on the choice of estimator is discussed in Section 6.2.4.
6.2.1.2 "Simple" Lead Hazard Screen
Only Type I error probabilities for the three statistics were calculated for a "simple" lead
hazard screen. As discussed in Section 5.2, these probabilities do not indicate whether a home
incorrectly failed the media standards, but whether a home incorrectly failed a lead hazard
screen. This precludes Type n error probabilities being presented for the "simple" lead hazard
screen. Figure 6-10 presents, for the Rochester data, graphs of the error probabilities for the
three estimators when two floor and window well samples were collected, as calculated under the
Interim Guidance standards, while Figures H-5 and H-6 present similar graphs when three and
four dust samples are taken. Table 6-25 presents the actual probabilities included in the graph
when two, three, and four floor dust and window well dust samples are taken.
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Error Probability °«r • Rang* of Trua Condition!
UlUlg noon Dull La*d Hazard Scrvaa Standard
(Two Samplaa)
1.0
08
oa
0.7
i 0.8
I "
I"
0.3
0.2
0,1
0.0
C»om«tric lf*«n
Arithmetic Mean
10 20 30 40 DO 00 70
7ru« Houi* Geometric M«an Du»t Land Loadinf (ui/ft2)
BO
on Floors
Error Probability ov«r a Rang* of Tru« Condition*
Uilnf Window Sill* Duvt L*«d H«x«rd Scr»«n 3t.t>d«rd
(Two Sampl««)
08
0.7-
i H
0.3
0.3
0.1
0.0-
E»tlm«tor«:
Geomatrlc Ifean
• Arithmetic U*an
100 200 300 400
Tru« Houu G«om«trlc U.»n Du«t L«ad Loading (ug/UZ) on Window Sill*
Error Probabilitf o-rmr • Reaig" of Trua Condition*
Uvlng Window Will* Duct Lead Hazard Screen Standard
(Two Sample.)
1.0
O.D
0.5
0.7
i 0.8
P 0.6
I"
0.3
0.2
0.1
0.0
Evtlmaton:
G.omamc Maan
- - Arithmetic Mean
100 200 300 400 BOO BOO TOO
Trua Houn Gaom.tric M.an Dual Laad Loadini (u./Il8) on Window Wall.
Figure 6-10. Comparison of "Simple" Lead Hazard Screen Geometric Mean, Arithmetic
Mean, and Maximum Value Error Probabilities for Two Floor and Window Well
Dust Samples Using the Interim Guidance Standards - Variance Components
from the Rochester Lead-in-Dust Study Homes.
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Table 6-25.
"Simple" Lead Hazard Screen Error Probabilities for Each Statistic Over a
Range of Assumed True House Lead Levels For Two. Three, and Four Floor
and Window Well Dust Samples Using the Interim Guidance Standards1 -
Variance Components From the Rochester Lead-in-Dust Study Data.
j=^=^=^=^=
Location
^_^_^=^^^^^^^
Floors
Window
Sills
Window Wells
^— ^^^^™=^=
=^==^=
Number of
Samples
^^^^^=^=^^^
2
3
4
2
3
4
2
3
4
=^==
Assumed
•True" House
Dust Lead
Loading too/ft1)
30
50
70
100
30
50
70
100
30
50
70
100
100
i 250
400
500
100
400
500
100
250
400
200
400
600
800
200
400
600
800
200
400
600
800
Type I Error Probability
Under the
Geometric
0.216
0.500
0.697
0.856
0.168
0.500
0.737
0.904
0.134
0.500
0.768
0.934
0.128
0.500
0.720
0.805
0.082
0.500
0.762
0.853
0.054
0.500
0.795
0.888
0.294
0.500
0.624
0.706
0.253
0.500
0.651
0.747
0.222
0.500
0.673
0.778
Under the
Arithmetic Mean
0.318
0.591
0.761
0.887
0.326
0.649
0.839
0.944
0.328
0.730
0.890
0.976
0.196
0.600
0.793
0.869
0.214
0.677
0.865
0.924
0.226
0.762
0.917
0.964
0.442
0.649
0.727
0.797
0.507
0.754
0.830
0.881
0.561
0.801
0.883
0.936
Under the
Maximum Value II
0.495 II
0.750
0.872
0.949
0.641
0.875
0.954
0.988
0.745
0.938
0.984
0.997
0.378
0.750
0.884
0.926
0.509
0.875
0.961
0.980
0.613
0.938
0.987
0.995
0.579
0.750
0.831
0.877
0.726
0.875
0.930
0.957
0.822
0.938
0.971
0.985
1 The floor dust wipe standard at which a home fails the assessment was assumed to be 50 /;g/fta and^the
window well dust wipe standard at which a home fails the assessment was assumed to be 400 //g/ft2.
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Since a risk assessor must perform a full risk assessment when a home fails the lead
hazard screen, the Type I error probabilities give an indication of the percent of time a full risk
assessment may have to be performed in addition to the lead hazard screening. For instance, in
Table 6-25 consider when four floor dust samples are used in the error probability calculations
and the assumed true house floor dust-lead loading is 30 ug/ft2, i.e., below the hazard screen
Interim Guidance cut-off of 50 ug/ft2. The probability of incorrectly failing a home is 0.134 for
the geometric mean, 0.328 for the arithmetic mean, and 0.745 for the maximum value. That is,
when the maximum value is used to characterize the floor dust-lead loadings in the home, 74.5%
of the time a home will fail the lead hazard screen forcing an additional testing through a full risk
assessment even though the true lead levels were below the standard. This high incorrect failure
rate for the maximum value has a high monetary value since two assessments will need to be
performed when in fact, the less costly lead hazard screen may have been appropriate in passing
the home if another estimator were used to characterize the lead levels in the home. As shown in
Figures H-7 through H-9 and Table H-5, similar observations can be made for the Rhode Island
data.
6.2.3 Effect of the Number of Media Samples Collected
As discussed in the performance characteristics analysis, the Section 402 protocols do not
require a risk assessor to collect a specific number of samples. For example, the
recommendation in the HUD Guidelines is to collect between 6 and 8 floor, window sill, and
window well dust samples. This analysis assesses the effect of collecting 2, 3, and 4 floor dust,
window sill dust, window well dust, and soil samples on the ability to identify a lead hazard.
Consider Table 6-26, below, which presents a summary of the Type I error probabilities
as the number of samples increases, under the Interim Guidance standards during a risk
assessment and the variance components as estimated from the Rochester Study data.
Table 6-26 illustrates that the level of protection in a risk assessment is dependent on the
number of samples collected. For instance, consider when the true average window sill dust-lead
loading is assumed to be 250 ug/ft2 (i.e., half the standard). The Type I error rates for the
geometric mean are 0.195,0.147, and 0.112 when 2,3, and 4 rooms are sampled respectively.
For the arithmetic mean, the rates are 0.304,0.316, and 0.335 for 2,3, and 4 rooms sampled, and
the rates are 0.470,0.614, and 0.719 for the maximum value when 2,3, and 4 rooms are sampled,
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Table 6-26. Summary of the Type I Error Probabilities when Two. Three, and Four Floor.
Window Sill, and Window Well Dust and Soil Samples are Collected for a
Risk Assessment Under the Interim Guidance Standards - Variance
Components From the Rochester Lead-in-Dust Study Data.
Media/Component
(Assumed "True" Media Level)
Floor Dust
(50/yg/ft1)
Window Sill Dust
(250^g/ft2)
Window Well Dust
(400^g/ft»)
Soil (Boundary)
(250(V/g/g)
Number of Samples
2
3
4
2
3
4
2
3
4
2
3
4
Type 1 Error Probability
Geometric
Mean
0.144
0.096
0.066
0.195
0.147
0.112
0.294
0.253
0.222
0.022
0.007
0.002
Arithmetic
Mean
0.237
0.231
0.206
0.304
0.316
0.335
0.475
0.537
0.578
0.046
0.022
0.011
Maximum
Value
0.401
0.536
0.641
0.470
0.614
0.719
0.579
0.726
0.822
0.150
0.217
0.278
respectively. These observations are similar for the "compound" lead hazard screen and for the
Rhode Island Department of health data. Tables 6-21 through 6-25 and H-l through H-4 present
all the Type I and Type II error probabilities.
In general, across all media and data sets, as the number of samples increase the Type I
probability of error for the maximum value increases. The arithmetic mean and geometric mean
error probabilities are not as dependent on the number of samples collected and either increase or
decrease as the number of samples increase. One notable exception to the geometric mean
Type I error probabilities occurs for the "compound" lead hazard screen. For both the floors and
the window wells in the Rochester and Rhode Island data, the error probabilities increase as the
number of samples increase when the true house media lead loading is equal to the media
standard. The Type n error probabilities all decrease as the number of samples increase for all
three statistics.
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6.2.4 Effect of the Interim Guidance and Proposed Rule Standards on the Error
Probabilities
To assess the impact the Proposed Rule reduced dust and soil standards have on the
Type I and Type H error probabilities, consider Tables 6-27 and 6-28 which present summaries
of the Type I and Type H error probabilities for 2,3, and 4 floor dust, window sill dust, and soil
samples when the error probabilities are calculated under the Interim Guidance and Proposed
Rule standards and the Rochester and CAP variance components are used. Note that the error
probability results and graphs for the Proposed Rule standards, similar to those already presented
for the Interim Guidance standards, can be found in Appendix I.
Table 6-27. Summary of Type I Error Probabilities for Two, Three, and Four Floor Dust,
Window Sill Dust, and Soil Samples Under the Interim Guidance and
Proposed Rule Standards - Variance Components from the Rochester Lead-
in-Dust Study Data and the CAP Study Data.
Floor Dust
Window Sill
Oust
Soil
(Foundation)
Number
of
«_____
2
3
4
2
3
4
2
3
4
Assumed
•True"
House Lead
Level
25
50
25
50
25
50
100
250
100
250
100
250
1,000
2,000
1,000
2,000
1,000
2 000
Type 1 Error
Interim Guidance
Arithmetic
Mean
0.050
0.237
0.002
0.231
0.001
0 206
0.057
0.304
0.052
0.316
0.033
0 335
0.004
0.093
0.002
0.082
0.000
0050
Geometric
Mean
0.002
0.144
0.001
0.096
0.000
0.066
0.023
0.195
0.007
0.147
0.002
0.112
0.002
0.047
0.000
0.020
0.000
0.009
Maximum
Value
0.150
0.401
0.200
0.536
0.275
0.641
0.152
0.470
0.220
0.614
0.282
0.719
0.038
0.224
0.056
0.316
0.074
0.397
Proposed Rule
Arithmetic
Mean
0.237
0.598
0.231
0.660
0.206
0.730
0.249
0.610
0.239
0.681
0.202
0.763
0.173
0.587
0.155
0.645
0.132
0.709
Geometric
Mean
0.144
0.500
0.096
0.500
0.066
0.500
0.128
0.500
0.082
0.500
0.054
0.500
0.103
0.500
0.061
0.500
0.037
0.500
Maximum
Value
0.401
0.750
0.536
0.875
0.641
0.938
0.378
0.750
0.509
0.875
0.613
0.938
0.337
0.750
0.460
0.875
0.561
0.938
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Table 6-28. Summary of Type II Error Probabilities for Two. Three, and Four Floor Dust,
Window Sill Dust, and Soil Samples Under the Interim Guidance and
Proposed Rule Standards - Variance Components from the Rochester Lead-
in-Dust Study Data and the CAP Study Data.
Assessment
Floor Dust
Window Sill
Dust
Soil
Number
of
Rooms
2
3
4
2
3
4
2
3
4
Assumed
"True-
House Lead
Level
150
750
6.000
Type II Error
Interim Guidance
Arithmetic
Mean
0.216
0.148
0073
0.242
0.163
0.091
0.278
0.234
0 160
Geometric
Mean
0.267
0.223
0.189
0.308
0.269
0.239
0.370
0.342
0.319
Maximum
Value
0.109
0.036
0.012
0.131
0.047
0.017
0.166
0.067
0.027
Proposed Rule
Arithmetic
Mean
0.026
0.010
0.002
0.053
0.024
0.006
0.016
0.004
0.001
Geometric
Mean
0.046
0.019
0.009
0.087
0.048
0.027
0.023
0.007
0.002
Maximum
Value
0.014
0.002
< 0.001
0.028
0.005
0.001
0.006
<0.001
< 0.001
In general, lowering the standards as in the Proposed Rule may lower the probability of a
wrong decision. For discussion of this point, ignore that the Proposed Rule requires the
arithmetic mean for floor dust, window sill dust, and soil samples, and compare the Type II
maximum value error probability shown in Table 6-28, when four samples are collected for floor
dust during a risk assessment and the assumed "true" house floor dust lead loading is 150 ug/ft2.
This comparison shows that under the Interim Guidance the maximum value error is 0.012 while
the Proposed Rule error probability is O.OOl. This illustrates a reduction in the chances of
incorrectly passing a home when it should have failed. Now consider the same risk assessment,
but assume the true house floor dust lead loading is 25 ug/ft2. From Table 6-27, the Interim
Guidance probability of incorrectly failing a home when it should have failed is 0.275 while the
Proposed Rule Type I error probability is 0.641. This illustrates a large increase in the chances
of incorrectly failing a home when it should have passed. Therefore, the Proposed Standards,
when using a maximum value, have made the chances of incorrectly passing lower but have
increased the chances of incorrectly failing.
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The Proposed Rule requires the arithmetic mean of the floor dust, window sill dust, and
soil samples be compared to the Proposed Rule standards. To understand the implications of the
change in the estimator as well as the decrease in the media standards consider the same
scenarios described above. When four floor dust samples are collected for a risk assessment and
the house floor dust-lead loading is assumed to be 150 fig/ft2 the Interim Guidance Type D error
is still 0.012, but the Proposed Rule Type II error probability using the arithmetic mean is 0.002.
When a true house floor dust-lead loading is assumed to be 25 ug/ft2, the Type I error probability
is 0.275 for the Interim Guidance and 0.206 for the Proposed Rule when the arithmetic mean is
used. This comparison illustrates that the Proposed Rule showed slight decreases in the chances
of incorrectly passing a home when it should have failed and moderate decreases in the chance of
incorrectly failing a home when it should have passed. The combination of lowering the
standards and using the arithmetic mean as the characterization of floor dust lead, window sill
dust lead, and soil lead in the home, as described in the Proposed Rule, seems to have improved
the discrimination of the risk assessment.
6.3 OBJECTIVE 3; ASSESSMENT OF SAMPLING LOCATIONS RISK ASSESSORS MAY
WANT TO TARGET
Section 402 does not require risk assessors to collect dust samples from specific rooms.
The purpose of this analysis is to assess whether certain rooms may want to be sampled to best
assess the dust lead hazard in the home. Two types of analyses were conducted using the
Rochester data: a correlation analysis and a pathways model analysis. The results from each are
discussed below. The specifics of the analysis calculations were presented in Section 5.3.
6.3.1 Correlation Analysis Results
Pearson correlation coefficients were calculated between log-transformed blood-lead
concentrations and log-transformed dust-lead loadings for the dust-wipe samples presented in
Table 5-4. These correlations are found in Table J-l of Appendix J. This table shows that, at the
0.05 level, the log-transformed blood-lead concentrations were significantly positively correlated
with the log-transformed dust-lead loadings for all rooms and components except living room
floors and living room window sills. The significant correlations ranged from 0.20 for play area
window wells to 0.33 for bedroom window sills. The reason for the lack of significant
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correlations between blood-lead concentrations and living room dust-lead loadings may be due to
small sample size rather than lack of a linear relationship. Only 41 homes had floor dust wipe
samples taken in the living room, and only 31 homes had window sill dust samples taken in the
living room. Due to the small sample size, dust-wipe data from living rooms were not included
in the pathways analysis.
The most statistically significant correlations among the log-transformed dust-lead
loadings from different rooms and components occurred between the kitchen and play area
window wells (r = 0.65), the interior entryway and kitchen floors (r = 0.52), and the play area and
bedroom floors (r = 0.51). The correlations provided an indication of relationships that may be
present and that were more closely examined in the pathways model analysis.
6.3.2 Pathways Model Results
Figure 6-11 illustrates those pathways found to be statistically significant at the 0.05 level
in this analysis, and Table J-2 in Appendix J provides the parameter estimates from the structural
equation modeling analysis. Note that the natural log-transformed data was used to generate the
parameter estimates in Table J-2, making interpretation of the parameter estimates difficult. The
purpose of this analysis was not merely to obtain estimates of model parameters, but to indicate
those rooms or components that may be most highly recommended for dust-wipe sampling
during risk assessment activities.
The results shown in Figure 6-11 indicate that the play area floor dust was a direct
pathway to blood. No other statistically significant pathways of lead exposure to the blood were
observed in this analysis. The window well was directly related to the window sill dust in the
play area, but neither were found to be pathways of lead to the floor dust in this room. The
interior entryway dust and the bedroom window sill dust were direct pathways of lead exposure
for the bedroom floor, while the bedroom window wells were an indirect pathway through the
bedroom window sill.
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Bedroom Window
Well Dust
Bedroom Window
Sill Oust
Bedroom Floor Dust
BLOOD
Interior Entryway
Floor Dust
Hay Area Window
Sill Dust
Play Area Window
Well Dust
Play Area Floor Dust
Figure 6-11. Statistically Significant Pathways of Lead Exposure Using the
Rochester Study Data.
These results indicate that risk assessor may want to consider taking dust-wipe samples in
the child's play area to obtain the best information on potential lead hazards available to the
child. In, addition, in both the bedroom and the play area, the window wells were direct
pathways of lead to the window sills. This indicates that sampling one or the other may provide
the same information as sampling both.
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7.0 DISCUSSION
This section discusses how the performance characteristic and error probability results
seen in Section 6 compare, how the pathways results in this report compare to results in the
literature, and the impact of the changing from the Interim Guidance standards to the Proposed
Rule standards.
7.1 PERFORMANCE CHARACTERISTICS AND ERROR PROBABILITIES
For Objectives 1 and 2, two types of analysis methods were used to examine how the
different standards, sampling schemes, and statistics used to characterize the lead levels in a
home affect the probability of correctly identifying a lead-based paint health hazards in a home.
The Objective 1 analysis used performance characteristics while the Objective 2 analysis used
error probabilities. Table 7-1 below lists the probabilities calculated for the performance
characteristic and the error probability analysis.
Table 7-1. Probabilities Calculated for the Performance Characteristic and Error Probability
Analysis.
Sensitivity:
Specificity:
PPV:
NPV:
Poffor
P(Y
P{Y
P(B
P(B
mance Characteristics
iS | Bi 10/yg/dL)
< S | B < 10j/g/dL)
2 10//g/dL | Yi S)
< 10j/g/dL | Y < S)
Error Probability
Type I Error: P(Y 2 S | u <
Type II Error: P(Y < S | // 2
S)
S)
Note: Y = Calculated lead level in the home for component/media/statistic
S = Standard for the component/media
B = Child's blood lead concentration
ji = Assumed 'true* average lead level in the home for component/media
The performance characteristics measure the probability of identifying a health hazard
available to a child through the lead found in the home while the error probabilities assess the
probability of correctly of incorrectly identifying lead hazards present in the home.
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7.2 PATHWAYS ANALYSIS
The approach of the Objective 3 analysis, a pathways analyses using structural equation
models, has been performed over the last several years to evaluate and understand the sources
and routes by which children are exposed to lead. One example of such an analysis is in the EPA
draft report titled, "Analysis of Pathways of Residential Lead Exposure in Children." This report
by design assesses whether lead found in a child's home environment directly or indirectly
impacts the child's blood lead concentration. Sources of lead that were assessed included floor
dust, interior entryway dust, exterior entryway dust, window sill dust, window well dust, water,
air ducts, and soil. The objectives of these types of analyses are quite different from that for the
pathways analysis conducted in this report.
The purpose of the pathways analysis in this report was to assess which interior dust
sampling locations a risk assessor may want to target in order to ensure that the best evaluation
of the potential lead hazard to a child is made. In this analysis, floor dust, window sill, and
window well dust wipe samples from various locations in the home including the kitchen,
interior entryway, play area and bedroom, were assessed, while no other sources of lead were
considered. Generally, dust sample results from the various rooms are averaged into one dust
measurement for the home, according to type of component. The analysis for this report focused
on how to incorporate sampling location into this measurement.
The results of the pathways analysis using the Rochester Study data indicated that the
play area floor dust-lead is the only direct contributor to the child's blood-lead concentration.
The bedroom window well dust-lead was a direct contributor to the bedroom window sill dust-
lead which in turn contributed to the bedroom floor dust-lead. Similarly, the play area window
well dust-lead contributed to the play area window sill dust-lead. An additional contributor to
the bedroom floor dust-lead was the interior entryway floor dust-lead. These results may
recommend that a risk assessor samples dust from the floor in a child's play area to gain an
understanding of the potential hazard available to a child. Note that this is consistent with the
intent of the Interim Guidance, the HUD Guidelines, and the Proposed Rule. In addition, since
the window well dust lead consistently contributes to the window sill dust lead, a risk assessor
may not need to sample from both places. The Proposed Rule seems to have addressed this
issue, recommending that sampling occur at the window sill and not requiring the window well
to be sampled in a risk assessment.
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7.3. PROPOSED RULE COMPARED TO THE INTERIM GUIDANCE
Overall, it appears that the Proposed Rule provides a better approach for performing risk
assessments than the Interim Guidelines. The combination of the lower media hazard standards,
removal of requirements for sampling from the window well, and the change to an arithmetic
mean estimator for characterizing the floor dust-lead, window sill dust-lead, and soil-lead seem
to provide a more accurate reflection of the hazards available in homes.
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8.0 REFERENCES
[1] Emond, M.J., Lanphear, B.P., Watts, A., Eberly, S. (1996) "Measurement Error and its
Impact on the Estimated Relationship Between Dust Lead and Children's Blood Lead."
Environmental Research. 72:82-92.
[2] Hollander and Wolfe, D. A., Nonparametric Statistical Methods. Wiley Press, 1 973.
[3] Lanphear, B.P., Weitzman, M., Winter, N.L., Eberly, S., Yakir, B., Tanner, M.,
Emond, M., and Matte, T. (1996) "Lead-contaminated House Dust and Urban Children's
Blood-Lead Levels." American Journal of Public Health. 86(10): 1416-1421.
[4] U.S. Environmental Protection Agency, "Guidance on Identification of Lead-Based Paint
Hazards", MepOHmdtlmTederal Register, pp.47248-47257, September 11, 1995.
[5] U.S. Environmental Protection Agency, "Lead: Requirements for Lead-Based Paint
Activities in Target Housing and Child-Occupied Facilities, Final Rule'VMemorandmn-*
Federal Register, pp. 45777-45830, August 29, 1996.
[6] U.S. Environmental Protection Agency, Lead-Based Paint Risk Assessment Model
Curriculum prepared, 1995 for the Chemical Management Division.
[7] U.S. Department of Housing and Urban Development, "Guideline for the Evaluation and
Control of Lead-Based Paint Hazards in Housing," Office of Lead-Based Paint
Abatement and Poisoning Prevention, HUD-1539-L'BP, July 1995.
[8] The University of Rochester School of Medicine and The National Center for Lead-Safe
Housing (1995) "The Relation of Lead-Contaminated House Dust and Blood Lead Levels
Among Urban Children: Volumes I and II." Departments of pediatrics, biostatistics, and
Environmental Medicine, The Rochester School of Medicine, Rochester, New York, and
the National Center for Lead-Safe Housing, Columbia, Maryland, June, 1995.
[9] Morbidity and Mortality Weekly Report, CDC, Vol. 46, No. 7, February 21, 1997.
'
»
• C^DC S
[10] Lanphear, B.P., Weitzman, M., and Eberly, S. (1996) "Racial Differences in Urban
Children's Environmental Exposures to Lead." American Journal of Public Health 86
(10): 1460-1463.
[1 1] Lanphear, B.P., Weitzman, M., Winter, N.L., Eberly, S., Yakir, B., Tanner, M.,
Emond, M., and Matte, T. (1996) "Lead-Contaminated House Dust and Urban
Children's Blood-Lead Levels." American Journal of Public Health. 86(10): 1416-1421.
[12] Emond, M.J., Lanphear, B.P., Watts, A., Eberly, S. (1996) "Measurement Error and Its
Impact on the Estimated Relationship Between Dust Lead and Children's Blood Lead."
Environmental Research. 72: 82-92.
Draft Report - Do Not Quote, Cite, Copy or Distribute February 15, 1999 103
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[13] Bomschein, R.L., Succop, P., Dietrich, K.N., Clark, C.S., Que Hee, S., and Hammond,
P.B. (1985) 'The Influence of Social and Environmental Factors in Dust Lead, Hand
Lead, and Blood Lead Levels in Young Children." Environmental Research. 38:108-
118.
[14] Bomschein, R.L., Succop, P.A., Krafft, K.M., Clark, C.S., Peace, B., and Hammond, P.B.
(1986) "Exterior Surface Dust Lead, Interior House Dust Lead and Childhood Lead
Exposure in an Urban Environment." in Trace Substances in Environmental Health, II,
1986. A symposium edited by D.D. Hemphill (University of Missouri, Columbia).
[15] Bomschein, R.L., Clark, C.S., Grote, J., Peace, B., Roda, S., and Succop, P. (1988) "Soil
Lead - Blood Lead Relationship in a Former Lead Mining Town." Lead in Soil. 149-160.
[16] Menton, Ronald G., David A. Burgoon, and Allan H. Marcus, (1993) "Pathways of Lead
Contamination for the Brigham and Women's Hospital Longitudinal Lead Study" in
Beard, Michael E. and S.D. Allen Iske, ed., Lead in Paint. Soil, and Dust: Health Risks.
Exposure Studies. Control Measures. Measurement Methods, and Quality Assurance, and
STP; 1226,1993 ASTM Boulder Conference on Lead in Paint, Soil, and Dust.
[17] Sayre, J. (1981) "Dust Lead Contribution to Lead in Children." Environmental Lead.
23-40.
[18] Chou, Y.L., Kinateder, J.G., Hartford, P.A., Lordo, R.A., McMillan, N., and Tsai, H.C.,
"Components of Variation of Lead in Household Dust, Soil, and Paint", Peer Review
Draft prepared by Battelle to the Office of Pollution Prevention and Toxics, U.S.
Environmental Protection Agency, EPA Contract Number 68-D5-0008, June 10,1998.
[19] Lead-Based Paint Risk Assessment Model Curriculum prepared, 1995 for the U.S.
Environmental Protection Agency, Chemical Management Division.
[20] U.S. Environmental Protection Agency, "Lead; Identification of Dangerous Levels of
Lead; Proposed Rule," Federal Register, Part m, 40 CFR, Part 745, pp. 30301-30355,
June 3,1998.
[21] U.S. Environmental Protection Agency, "Final Report for the Comprehensive Abatement
Performance Study Volume I: Summary Report," Office of Prevention Pesticides, and
Toxic Substances, U.S. Environmental Protection Agency. EPA 230-R-94-013a, April,
1996.
[22] U.S. Environmental Protection Agency, "Final Report for the Comprehensive Abatement
Performance Study Volume II: Summary Report," Office of Prevention Pesticides, and
Toxic Substances, U.S. Environmental Protection Agency. EPA 230-R-94-013b, April,
1996.
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APPENDIX A
Section 402 Guidance for Risk Analysis Procedures
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APPENDIX A
Section 402 Guidance for Risk Analysis Procedures
The following are excerpts from the U.S. EPA Memorafiaum Federal Register titled
"Lead: Requirements for Lead-Based Paint Activities in Target Housing and Child-Occupied
Facilities, Final Rule" and dated August 29, 1996. The information below are direct quotations
from the document that are applicable to the work presented in this document.
SUMMARY:
EPA is finalizing a Federal regulation under section 402 of the Toxic Substance Control
Act (TSCA) to ensure that individuals conducting lead-based paint activities in target housing
and child-occupied facilities are properly trained and certified, that training programs providing
instruction in such activities are accredited and that these activities are conducted according to
reliable, effective and safe work practice standards. The Agency is also finalizing a Federal
regulation under section 404 of TSCA that will allow States and Indian Tribes to seek
authorization to administer and enforce the regulations developed under section 402. The goal of
this regulation is to ensure the availability of a trained and qualified workforce to identify and
address lead-based paint hazards, and to protect the general public from exposure to lead hazards.
______ •
Section 745.227 Work practice standards for conducting lead-based paint activities:
target housing and child-occupied facilities.
(a) Effective date, applicability, and terms.
(1) Beginning on March 1, 1999, all lead-based paint activities shall be performed
pursuant to the work practice standards contained in this section.
(2) When performing any lead-based paint activity described by the certified individual as
an inspection, lead-hazard screen, risk assessment or abatement, a certified individual must
perform that activity in compliance with the appropriate requirements below.
(3) Documented methodologies that are appropriate for this section are found in the
following: The U.S. Department of Housing and Urban Development (HUD) Guidelines for the
Evaluation and Control of Lead-Based Paint Hazards in Housing; the EPA Guidance on
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Residential Lead-Based Paint, Lead-Contaminated Dust, and Lead-Contaminated Soil; the EPA
Residential Sampling for Lead: Protocols for Dust and Soil Sampling (EPA report number
7474-R-95-001); Regulations, guidance, methods or protocols issued by States and Indian Tribes
that have been authorized by EPA; and other equivalent methods and guidelines.
(4) Clearance levels are appropriate for the purposes of this section may be found in the
EPA Guidance on Residential Lead-Based Paint, Lead-Contaminated Dust, and Lead
Contaminated Soil or other equivalent guidelines.
(b) Inspection.
(1) An inspection shall be conducted only by a person certified by EPA as an inspector or
risk assessor and, if conducted, must be conducted according to the procedures in this paragraph.
(2) When conducting an inspection, the following locations shall be selected according to
documented methodologies and tested for the presence of lead-based paint: (i) In a residential
dwelling and child-occupied facility, each component with a distinct painting history and each
exterior component with a distinct painting history shall be tested for lead-based paint, except
those components that the inspector or risk assessor determines to have been replaced after 1978,
or to not contain lead-based paint; and (ii) In a multi-family dwelling or child-occupied facility,
each component with a distinct painting history in every common area, except those components
that the inspector or risk assessor determines to have been replaced after 1978, or to not contain
lead-based paint.
(3) Paint shall be sampled in the following manner: (i) The analysis of paint to determine
the presence of lead shall be conducted using documented methodologies which incorporate
adequate quality control procedures; and/or (ii) All collected paint chip samples shall be
analyzed according to paragraph (i) of this section to determine if they contain detectable levels
of lead that can be quantified numerically.
(4) The certified inspector or risk assessor shall prepare an inspection report which shall
include the following information: (i) Date of each inspection, (ii) Address of building, (iii)
Date of construction, (iv) Apartment numbers (if applicable), (v) Name, address, and telephone
number of the owner or owners of each residential dwelling or child-occupied facility, (vi)
Name, signature, and certification number of each certified inspector and/or risk assessor
conducting testing, (vii) Name, address, and telephone number of the certified firm employing
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each inspector and/or risk assessor, if applicable, (viii) Each testing method and device and/or
sampling procedure employed for paint analysis, including quality control data and, if used, the
serial number of any x-ray fluorescence (XRF) device, (ix) Specific locations of each painted
component tested for the presence of lead-based paint, (x) The results of the inspection
expressed in terms appropriate to the sampling method used.
(c) Lead hazard screen.
(1) A lead hazard screen shall be conducted only by a person certified by EPA as a risk
assessor.
(2) If conducted, a lead hazard screen shall be conducted as follows: (i) Background
information regarding the physical characteristics of the residential dwelling or child-occupied
facility and occupant use patterns that may cause lead-based paint exposure to one or more
children age 6 years and under shall be collected, (ii) A visual inspection of the residential
dwelling or child-occupied facility shall be conducted to: (A) Determine if any deteriorated paint
is present, and (B) Locate at least two dust sampling locations, (iii) If deteriorated paint is
present, each surface with deteriorated paint, which is determined, using documented
methodologies, to be in poor condition and to have a distinct painting history, shall be tested for
the presence of lead, (iv) In residential dwellings, two composite dust samples shall be collected,
one from the floors and the other from the windows, in rooms, hallways or stairwells where one
or more children, age 6 and under, are most likely to come in contact with dust, (v) In
multi-family dwellings and child-occupied facilities, in addition to the floor and window samples
required in paragraph (c)(l)(iii) of this section, the risk assessor shall also collect composite dust
samples from common areas where one or more children, age 6 and under, are most likely to
come into contact with dust.
(3) Dust samples shall be collected and analyzed in the following manner: (i) All dust
samples shall be taken using documented methodologies that incorporate adequate quality
control procedures, (ii) All collected dust samples shall be analyzed according to paragraph (f)
of this section to determine if they contain detectable levels of lead that can be quantified
numerically.
(4) Paint shall be sampled in the following manner: (i) The analysis of paint to determine
the presence of lead shall be conducted using documented methodologies which incorporate
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adequate quality control procedures; and/or (ii) All collected paint chip samples shall be
analyzed according to paragraph (f) of this section to determine if they contain detectable levels
of lead that can be quantified numerically.
(5) The risk assessor shall prepare a lead hazard screen report, which shall include the
following information: (i) The information required in a risk assessment report as specified in
paragraph (d) of this section, including paragraphs (d)(l l)(i) through (d)(l l)(xiv), and excluding
paragraphs (d)(l l)(xv) through (d)(l l)(xviii) of this section. Additionally, any background
information collected pursuant to paragraph (c)(2)(i) of this section shall be included in the risk
assessment report; and (ii) Recommendations, if warranted, for a follow-up risk assessment, and
as appropriate, any further actions.
(d) Risk assessment.
(1) A risk assessment shall be conducted only by a person certified by EPA as a risk
assessor and, if conducted, must be conducted according to the procedures in this paragraph.
(2) A visual inspection for risk assessment of the residential dwelling or child-occupied
facility shall be undertaken to locate the existence of deteriorated paint, assess the extent and
causes of the deterioration, and other potential lead-based paint hazards.
(3) Background information regarding the physical characteristics of the residential
dwelling or child-occupied facility and occupant use patterns that may cause lead-based paint
exposure to one or more children age 6 years and under shall be collected.
(4) Each surface with deteriorated paint, which is determined, using documented
methodologies, to be in poor condition and to have a distinct painting history, shall be tested for
the presence of lead. Each other surface determined, using documented methodologies, to be a
potential lead-based paint hazard and having a distinct painting history, shall also be tested for
the presence of lead.
(5) In residential dwellings, dust samples (either composite or single-surface samples)
from the window and floor shall be collected in all living areas where one or more children, age 6
and under, are most likely to come into contact with dust.
(6) For multi-family dwellings and child-occupied facilities, the samples required in
paragraph (d)(4) of this section shall be taken. In addition, window and floor dust samples
(either composite or single- surface samples) shall be collected in the following locations: (i)
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Common areas adjacent to the sampled residential dwelling or child-occupied facility; and (ii)
Other common areas in the building where the risk assessor determines that one or more
children, age 6 and under, are likely to come into contact with dust.
(7) For child-occupied facilities, window and floor dust samples (either composite or
single-surface samples) shall be collected in each room, hallway or stairwell utilized by one or
more children, age 6 and under, and in other common areas in the child-occupied facility where
the risk assessor determines one or more children, age 6 and under, are likely to come into
contact with dust.
(8) Soil samples shall be collected and analyzed for lead concentrations in the following
locations: (i) Exterior play areas where bare soil is present; and (ii) Dripline/foundation areas
where bare soil is present.
(9) Any paint, dust, or soil sampling or testing shall be conducted using documented
methodologies that incorporate adequate quality control procedures.
(10) Any collected paint chip, dust, or soil samples shall be analyzed according to
paragraph (f) of this section to determine if they contain detectable levels of lead that can be
quantified numerically.
(11) The certified risk assessor shall prepare a risk assessment report which shall include
the following information:
(i) Date of assessment.
(ii) Address of each building.
(iii) Date of construction of buildings.
(iv) Apartment number (if applicable).
(v) Name, address, and telephone number of each owner of each building.
(vi) Name, signature, and certification of the certified risk assessor conducting the
assessment.
(vii) Name, address, and telephone number of the certified firm employing each
certified risk assessor if applicable.
(viii) Name, address, and telephone number of each recognized laboratory conducting
analysis of collected samples.
(ix) Results of the visual inspection.
(x) Testing method and sampling procedure for paint analysis employed.
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(xi) Specific locations of each painted component tested for the presence of lead.
(xii) All data collected from on-site testing, including quality control data and, if used,
the serial number of any XRF device.
(xiii) All results of laboratory analysis on collected paint, soil, and dust samples.
(xiv) Any other sampling results.
(xv) Any background information collected pursuant to paragraph (d)(3) of this
section.
(xvi) To the extent that they are used as part of the lead-based paint hazard
determination, the results of any previous inspections or analyses for the presence
of lead-based paint, or other assessments of lead-based paint-related hazards.
(xvii) A description of the location, type, and severity of identified lead-based
paint hazards and any other potential lead hazards.
(xviii) A description of interim controls and/or abatement options for each identified
lead-based paint hazard and a suggested prioritization for addressing each hazard.
If the use of an encapsulant or enclosure is recommended, the report shall
recommend a maintenance and monitoring schedule for the encapsulant or
enclosure.
Section 745.223 Definitions.
The definitions in subpart A apply to this subpart. In addition, the following definitions
apply.
Abatement means any measure or set of measures designed to permanently eliminate
lead-based paint hazards. Abatement includes, but is not limited to:
(1) The removal of lead-based paint and lead-contaminated dust, the permanent enclosure
or encapsulation of lead-based paint, the replacement of lead-painted surfaces or fixtures, and the
removal or covering of lead-contaminated soil; and
(2) All preparation, cleanup, disposal, and post-abatement clearance testing activities
associated with such measures.
(3) Specifically, abatement includes, but is not limited to: (i) Projects for which there is a
written contract or other documentation, which provides that an individual or firm will be
conducting activities in or to a residential dwelling or child-occupied facility that: (A) Shall
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result in the permanent elimination of lead-based paint hazards; or (B) Are designed to
permanently eliminate lead-based paint hazards and are described in paragraphs (1) and (2) of
this definition, (ii) Projects resulting in the permanent elimination of lead-based paint hazards,
conducted by firms or individuals certified in accordance with Section 745.226, unless such
projects are covered by paragraph (4) of this definition; (iii) Projects resulting in the permanent
elimination of lead-based paint hazards, conducted by firms or individuals who, through their
company name or promotional literature, represent, advertise, or hold themselves out to be in the
business of performing lead-based paint activities as identified and defined by this section, unless
such projects are covered by paragraph (4) of this definition; or (iv) Projects resulting in the
permanent elimination of lead-based paint hazards, that are conducted in response to State or
local abatement orders.
(4) Abatement does not include renovation, remodeling, landscaping or other activities,
when such activities are not designed to permanently eliminate lead-based paint hazards, but,
instead, are designed to repair, restore, or remodel a given structure or dwelling, even though
these activities may incidentally result in a reduction or elimination of lead-based paint hazards.
Furthermore, abatement does not include interim controls, operations and maintenance activities,
or other measures and activities designed to temporarily, but not permanently, reduce lead-based
paint hazards.
Accredited training program means a training program that has been accredited by EPA
pursuant to Section 745.225 to provide training for individuals engaged in lead-based paint
activities.
Adequate quality control means a plan or design which ensures the authenticity, integrity,
and accuracy of samples, including dust, soil, and paint chip or paint film samples. Adequate
quality control also includes provisions for representative sampling.
Certified firm means a company, partnership, corporation, sole proprietorship,
association, or other business entity that performs lead-based paint activities to which EPA has
issued a certificate of approval pursuant to Section 745.226(f).
Certified inspector means an individual who has been trained by an accredited training
program, as defined by this section, and certified by EPA pursuant to Section 745.226 to conduct
inspections. A certified inspector also samples for the presence of lead in dust and soil for the
purposes of abatement clearance testing.
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Certified abatement worker means an individual who has been trained by an accredited
training program, as defined by this section, and certified by EPA pursuant to Section 745.226 to
perform abatements.
Certified project designer means an individual who has been trained by an accredited
training program, as defined by this section, and certified by EPA pursuant to Section 745.226 to
prepare abatement project designs, occupant protection plans, and abatement reports.
Certified risk assessor means an individual who has been trained by an accredited
training program, as defined by this section, and certified by EPA pursuant to Section 745.226 to
conduct risk assessments. A risk assessor also samples for the presence of lead in dust and soil
for the purposes of abatement clearance testing.
Certified supervisor means an individual who has been trained by an accredited training
program, as defined by this section, and certified by EPA pursuant to Section 745.226 to
supervise and conduct abatements, and to prepare occupant protection plans and abatement
reports.
Child-occupied facility means a building, or portion of a building, constructed prior to
1978, visited regularly by the same child, 6 years of age or under, on at least two different days
within any week (Sunday through Saturday period), provided that each day's visit lasts at least 3
hours and the combined weekly visit lasts at least 6 hours, and the combined annual visits last at
least 60 hours. Child-occupied facilities may include, but are not limited to, day-care centers,
preschools and kindergarten classrooms.
Clearance levels are values that indicate the maximum amount of lead permitted in dust
on a surface following completion of an abatement activity.
Common area means a portion of a building that is generally accessible to all occupants.
Such an area may include, but is not limited to, hallways, stairways, laundry and recreational
rooms, playgrounds, community centers, garages, and boundary fences.
Component or building component means specific design or structural elements or
fixtures of a building, residential dwelling, or child-occupied facility that are distinguished from
each other by form, function, and location. These include, but are not limited to, interior
components such as: ceilings, crown molding, walls, chair rails, doors, door trim, floors,
fireplaces, radiators and other heating units, shelves, shelf supports, stair treads, stair risers, stair
stringers, newel posts, railing caps, balustrades, windows and trim (including sashes, window
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heads, jambs, sills or stools and troughs), built in cabinets, columns, beams, bathroom vanities,
counter tops, and air conditioners; and exterior components such as: painted roofing, chimneys,
flashing, gutters and downspouts, ceilings, soffits, fascias, rake boards, comerboards, bulkheads,
doors and door trim, fences, floors, joists, lattice work, railings and railing caps, siding,
handrails, stair risers and treads, stair stringers, columns, balustrades, window sills or stools and
troughs, casings, sashes and wells, and air conditioners.
Containment means a process to protect workers and the environment by controlling
exposures to the lead-contaminated dust and debris created during an abatement.
Course agenda means an outline of the key topics to be covered during a training course,
including the time allotted to teach each topic.
Course test means an evaluation of the overall effectiveness of the training which shall
test the trainees' knowledge and retention of the topics covered during the course.
Course test blueprint means written documentation identifying the proportion of course
test questions devoted to each major topic in the course curriculum.
Deteriorated paint means paint that is cracking, flaking, chipping, peeling, or otherwise
separating from the substrate of a building component.
Discipline means one of the specific types or categories of lead-based paint activities
identified in this subpart for which individuals may receive training from accredited programs
and become certified by EPA. For example, "abatement worker" is a discipline. Distinct
painting history means the application history, as indicated by its visual appearance or a record of
application, over time, of paint or other surface coatings to a component or room. Documented
methodologies are methods or protocols used to sample for the presence of lead in paint, dust,
and soil.
Elevated blood lead level (EBL) means an excessive absorption of lead that is a
confirmed concentration of lead in whole blood of 20ug/dl (micrograms of lead per deciliter of
whole blood) for a single venous test or of 15-19ug/dl in two consecutive tests taken 3 to 4
months apart.
Encapsulant means a substance that forms a barrier between lead-based paint and the
environment using a liquid-applied coating (with or without reinforcement materials) or an
adhesively bonded covering material.
Encapsulation means the application of an encapsulant.
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Enclosure means the use of rigid, durable construction materials that are mechanically
fastened to the substrate in order to act as a barrier between lead-based paint and the
environment.
Guest instructor means an individual designated by the training program manager or
principal instructor to provide instruction specific to the lecture, hands-on activities, or work
practice components of a course.
Hands-on skills assessment means an evaluation which tests the trainees' ability to
satisfactorily perform the work practices and procedures identified in Section 745.225(d), as well
as any other skill taught in a training course.
Hazardous waste means any waste as defined in 40 CFR 261.3.
Inspection means a surface-by-surface investigation to determine the presence of
lead-based paint and the provision of a report explaining the results of the investigation.
Interim certification means the status of an individual who has successfully completed
the appropriate training course in a discipline from an accredited training program, as defined by
this section, but has not yet received formal certification in that discipline from EPA pursuant to
Section 745.226. Interim certifications expire 6 months after the completion of the training
course, and is equivalent to a certificate for the 6-month period.
Interim controls means a set of measures designed to temporarily reduce human exposure
or likely exposure to lead-based paint hazards, including specialized cleaning, repairs,
maintenance, painting, temporary containment, ongoing monitoring of lead-based paint hazards
or potential hazards, and the establishment and operation of management and resident education
programs.
Lead-based paint means paint or other surface coatings that contain lead equal to or in
excess of 1.0 milligrams per square centimeter or more than 0.5 percent by weight.
Lead-based paint activities means, in the case of target housing and child-occupied
facilities, inspection, risk assessment, and abatement, as defined in this subpart.
Lead-based paint hazard means any condition that causes exposure to lead from
lead-contaminated dust, lead-contaminated soil, or lead-contaminated paint that is deteriorated or
present in accessible surfaces, friction surfaces, or impact surfaces that would result in adverse
human health effects as identified by the Administrator pursuant to TSCA section 403.
i
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Lead-contaminated dust means surface dust in residential dwellings, or child-occupied
facilities that contains an area or mass concentration of lead at or in excess of levels identified by
the Administrator pursuant to TSCA section 403.
Lead-contaminated soil means bare soil on residential real property and on the property
of a child-occupied facility that contains lead at or in excess of levels identified by the
Administrator pursuant to TSCA section 403.
Lead-hazard screen is a limited risk assessment activity that involves limited paint and
dust sampling as described in Section 745.227(c).
Living area means any area of a residential dwelling used by one or more children age 6
and under, including, but not limited to, living rooms, kitchen areas, dens, play rooms, and
children's bedrooms.
Multi-family dwelling means a structure that contains more than one separate residential
dwelling unit, which is used or occupied, or intended to be used or occupied, in whole or in part,
as the home or residence of one or more persons.
Paint in poor condition means more than 10 square feet of deteriorated paint on exterior
components with large surface areas; or more than 2 square feet of deteriorated paint on interior
components with large surface areas (e.g., walls, ceilings, floors, doors); or more than 10 percent
of the total surface area of the component is deteriorated on interior or exterior components with
small surface areas (window sills, baseboards, soffits, trim).
Permanently covered soil means soil which has been separated from human contact by
the placement of a barrier consisting of solid, relatively impermeable materials, such as
pavement or concrete. Grass, mulch, and other landscaping materials are not considered
permanent covering.
Person means any natural or judicial person including any individual, corporation,
partnership, or association; any Indian Tribe, State, or political subdivision thereof; any interstate
body; and any department, agency, or instrumentality of the Federal government.
Principal instructor means the individual who has the primary responsibility for
organizing and teaching a particular course.
Recognized laboratory means an environmental laboratory recognized by EPA pursuant
to TSCA section 405(b) as being capable of performing an analysis for lead compounds in paint,
soil, and dust.
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Reduction means measures designed to reduce or eliminate human exposure to lead-based
paint hazards through methods including interim controls and abatement.
Residential dwelling means (1) a detached single family dwelling unit, including attached
structures such as porches and stoops; or (2) a single family dwelling unit in a structure that
contains more than one separate residential dwelling unit, which is used or occupied, or intended
to be used or occupied, in whole or in part, as the home or residence of one or more persons.
Risk assessment means (1) an on-site investigation to determine the existence, nature,
severity, and location of lead-based paint hazards, and (2) the provision of a report by the
individual or the firm conducting the risk assessment, explaining the results of the investigation
and options for reducing lead-based paint hazards.
Target housing means any housing constructed prior to 1978, except housing for the
elderly or persons with disabilities (unless any one or more children age 6 years or under resides
or is expected to reside in such housing for the elderly or persons with disabilities) or any
0-bedroom dwelling.
Training curriculum means an established set of course topics for instruction in an
accredited training program for a particular discipline designed to provide specialized knowledge
and skills.
Training hour means at least 50 minutes of actual learning, including, but not limited to,
time devoted to lecture, learning activities, small group activities, demonstrations, evaluations,
and/or hands-on experience.
Training manager means the individual responsible for administering a training program
and monitoring the performance of principal instructors and guest instructors.
Visual inspection for clearance testing means the visual examination of a residential
dwelling or a child-occupied facility following an abatement to determine whether or not the
abatement has been successfully completed.
Visual inspection for risk assessment means the visual examination of a residential
dwelling or a child-occupied facility to determine the existence of deteriorated lead-based paint
or other potential sources of lead-based paint hazards.
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IV. Relationship of Sections 402 and 404 to Section 403 of TSCA
Under section 403 of TSCA, EPA is developing a rule that will identify conditions of
lead-based paint, and lead levels and conditions in residential dust and soil that would result in a
hazard to building occupants, especially children age 6 and under. In combination with the work
practice standards contained in Section 745.227 of today's final rule, the Agency expects that the
levels and conditions identified in the TSCA section 403 rule will provide clear direction on how
to identify, prioritize and respond to hazards from lead in and around target housing.
VII. Framework for Work Practice Standards for Conducting Lead-Based Paint Activities
in Target Housing and Child-Occupied Facilities
A. Introduction
Section 745.227 establishes standards for conducting three lead-based paint activities:
inspection, risk assessment and abatement. In addition, Section 745.227 provides requirements
for conducting three related tasks that may be performed as either single tasks or as a part of an
inspection, risk assessment or abatement. These three tasks are: a lead hazard screen, laboratory
analysis, and composite dust sampling. Section 745.227 also establishes certain recordkeeping
requirements. This section of the rule also establishes the dates by which compliance with these
standards and procedures is required. The standards and procedures for conducting the
lead-based paint activities contained in Section 745.227 are being issued under authority of
TSCA section 402(a), which directs EPA to issue such standards, taking into account reliability,
effectiveness and safety.
B. Scope and Applicability
Under today's final rule, the standards for lead-based paint activities contained in Section
745.227 apply only in target housing and child-occupied facilities. Standards for lead-based
paint activities conducted in steel structures and public and commercial buildings, which had
been proposed on September 2,1994, will be addressed after further Agency review. A
discussion of the Agency's decision to address steel structures and public and commercial
buildings outside this rulemaking is presented in Unit II. A. of this preamble. Another important
feature of the standards contained in Section 745.227 is that they do not mandate circumstances
under which any particular lead-based paint activity must be performed. Instead the decision to,
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for example conduct an inspection, is left to the building owner. Additionally, the Agency is
preparing a rule under TSCA section 403 that will identify conditions of lead-based paint and
lead levels and conditions in residential soil and dust that would result in a hazard to building
occupants. Although the TSCA section 403 rule has not yet been proposed, Agency guidance on
this subject was issued July 14,1994, and is discussed in detail in Unit IV. of this preamble. The
section 403 Guidance also includes recommendations on actions that can be taken in response to
conditions of lead-based paint and lead levels and conditions in residential soil and dust. Until
the final section 403 rule is promulgated, the Agency recommends that individuals and firms
refer to the section 403 Guidance for assistance in identifying the presence of a lead-based paint
hazard and deciding whether to conduct lead-based paint activities. The primary purpose of the
standards in today's final rule is to provide certified individuals and firms with a set of minimum
requirements to be followed when conducting inspection, risk assessment or abatement activities.
These requirements are primarily procedural in nature: for inspection, risk assessment and
abatement activities, the standards specify the steps that EPA believes must be taken to conduct
those activities safely, effectively and reliably. For abatement activities, the standards also place
restrictions on certain techniques used to eliminate lead-based paint.
C. Use of Guidance and Recordkeeping Requirements
Today's final rule does not prescribe detailed work practices that should be followed for
each unique situation in which lead-based paint activities may be conducted. For that level of
detail, individuals should consult Federal and State guidance that provides specific instruction on
how to conduct inspection, risk assessment and abatement activities. These guidance documents
include: the U.S. Department of Housing and Urban Development's Guidelines for the Control
of Lead-Based Paint Hazards in Housing (HUD Guidelines) (Ref. 6), the section 403 Guidance,
EPA's Residential Sampling for Lead: Protocols for Dust and Soil Sampling (Ref. 7), and any
additional guidance issued by States or Indian Tribes that have been authorized by EPA under
Section 745.324 of this rule. While not regulatory requirements, these documents are
recommended by the Agency because they provide reliable and effective information on this
subject. Additionally, training courses that have been accredited by EPA or an EPA-authorized
State or Tribe will provide detailed instruction on inspection, risk assessment and abatement
standards and methodologies. To complement the existing guidance documents, the Agency is
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currently preparing a technical guidance document as a companion to this rule. The Agency will
distribute this guidance document to accredited training providers, the lead-based paint activities
contracting community, and State and local governments, prior to the date that compliance with
Section 745.225 of this rule is required. In its decision to recommend guidance as an adjunct to
the requirements at Section 745.227, the Agency carefully considered several factors, including
enforcement issues and comments received from the public on this approach. With regard to
enforcement, many of the work practice standards contained in Section 745.227 of today's final
rule, such as sampling methodologies and visual inspection techniques, refer to guidance. As a
result, the Agency recognizes that there are questions about the extent to which it will be able to
take an enforcement action against individuals who choose not to use the various guidance
recommended by EPA. Nonetheless, the Agency has many reasons for deciding to reference and
develop guidance as a supplement to this rule, rather than to promulgate rigid work practice
standards. The September 2,1994 proposal specifically requested comments on the use of
guidance as a supplement to the rule's basic regulatory requirements. In general, the majority of
commenters support the use of guidance as a supplement to the regulatory requirements
contained in Section 745.227. In some cases, commenters directly expressed their support,
whereas in other cases, commenters expressed neither support nor opposition. Overall, the
Agency believes that commenters accepted its proposed approach of referring to guidance. The
Agency believes there are several reasons to recommend guidance rather than to establish
detailed national work practice standards for the purposes of providing instruction on how to
conduct specific lead-based paint activities.
First, as discussed in the September 1994 proposed rule, the Agency drew from a large
body of existing information and research, and the input from a broad range of individuals and
groups, to develop its proposed regulatory standards for lead-based paint activities. Based on
that information and input, the standards proposed in September included strict reporting
requirements and documentation of the quality control measures and methodologies employed
when conducting inspection, risk assessment and abatement activities. These reporting and
documentation requirements remain a critical component of the standards established by today's
final rule. In combination with the rule's basic work practice standards, training, certification and
accreditation requirements, the reporting/documentation activities will help to ensure the
effectiveness of the standards and facilitate the use of guidance.
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A second reason for relying on non-regulatory guidance instead of rule-based standards is
the number of differences that can be found in the structure, design and occupant use patterns of
the residential dwellings and child-occupied facilities covered by this rule. For example, under
the standards for conducting a risk assessment at Section 745.227(d)(4), a risk assessor is
required to collect dust samples in rooms where children aged 6 years and under are most likely
to come into contact with dust. The rale does not prescribe precisely which rooms or how many
samples to collect, because the risk assessor needs to consider site-specific variables to determine
which rooms should be sampled and the number of samples that should be taken from each
room. These variables include: the size and number of rooms in the building; interior design
elements in a building and differences in designated play areas for a child; the location of
windows and doors; the condition of door frames, window troughs and stools; and occupant use
patterns.
As a specific example, in a small residential dwelling, a child may not have a separate
playroom, but may play in selected areas of one room or more, such as a corner in a living room
or dining room, or may have a bedroom that doubles as a playroom. On the other hand, in a
large residential dwelling, a child may have a separate playroom and bedroom, and certain areas
in a living room or family room for play activity. Furthermore, a child's pattern of use in a
residential dwelling can vary considerably, and that pattern may only be possible to determine
through an interview with a guardian.
Based on these and other variables that may be encountered when conducting a risk
assessment, inspection or abatement, the Agency believes that to try to anticipate and attempt to
list all circumstances that may be encountered would make the regulation overly prescriptive and
rigid. However, by establishing minimum requirements and basic procedures for conducting
inspection, risk assessment and abatement activities, the Agency is setting a safe, reliable and
effective baseline of steps for certified individuals and firms to follow to make sound decisions
based on site-specific conditions.
A third reason for the Agency's decision to avoid being overly prescriptive is the state of
technology within the lead-based paint activities field. Although there has been progress in the
development of new technologies to support specific lead-based paint identification techniques
and abatement methods, the Agency recognizes that the field is advancing and that the
technologies and methods that will help define it are still evolving.
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Consequently, the standards contained in today's final rule do not specify that certain
technologies or methods be utilized for sampling and analysis. Additionally, the rule does not
prescribe any specific methods or technologies for conducting an abatement, although it does
restrict certain work practices known to pose risks to building occupants, workers and the
environment.
As had been proposed, today's final rule relies on the use of documented methodologies
that incorporate adequate quality control measures. These methodologies and measures are
available in existing Federal and State guidance documents, and will be taught at accredited
training programs.
Although not overly detailed or prescriptive, EPA believes that the work practice
standards contained in today's final rule under Section 745.227 provide a baseline, which in
combination with the training, certification and accreditation requirements contained in Sections
745.225 and 745.226, will ensure that lead-based paint activities are conducted reliably, safely
and effectively.
VIII. Response to Comments on Work Practice Standards for Conducting Lead-Based
Paint Activities in Target Housing and Child-Occupied Facilities
B. Inspection
The objective of an inspection is to determine, and then report on, the existence of
lead-based paint through a surface-by-surface investigation of a residential dwelling or
child-occupied facility. As such, an inspection involves identifying the presence of lead in paint.
An inspection does not include taking dust or soil samples. An inspection must be conducted by
either a certified inspector or a certified risk assessor, and must include the provision of a report
explaining the results of the investigation.
The inspection standards contained in Section 745.227(b) reflect the Agency's decision
not to provide detailed regulatory requirements on how to perform specific lead-based paint
identification tasks, such as taking a paint chip sample or using an X-ray fluorescence (XRF)
device. In the final rule, the Agency also has removed specific requirements to use the HUD
Guidelines when collecting paint chip samples or when using an XRF device to test for the
presence of lead-based paint.
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Instead, the Agency requires that a lead-based paint inspection be conducted using
documented methodologies and adequate quality control measures. These documented
methodologies are defined as methods or protocols used to sample for the presence of lead in
paint, dust, and soil. Documented methodologies that are appropriate for the purposes of this
section may be found in: (1) The HUD Guidelines; the EPA Guidance on Residential
Lead-Based Paint, Lead-Contaminated Dust, and Lead-Contaminated Soil (60 FR 47248); the
EPA's Residential Sampling for Lead: Protocols for Dust and Soil Sampling and other EPA
sampling guidance; and (2) Regulations, guidance, methods or protocols issued by States and
Indian Tribes that have been authorized under Section 745.324. Additionally these
methodologies will be included in EPA's technical guidance on lead-based paint activities.
Although commenters generally supported this approach, at least three responses
suggested that the Agency provide detailed regulations for lead-based paint testing. However,
one of these commenters indicated that guidance may be an acceptable approach for establishing
testing protocols. These commenters were concerned about the enforcement issues associated
with the rule's dependence on documented methodologies, which to date have only been issued
by HUD, EPA and various State agencies, primarily as guidance.
However, other commenters did not object to the Agency's use of documented
methodologies, provided that records are kept as part of the inspection, and that such
methodologies are acknowledged as documented methodologies by EPA through future guidance
or regulations. As discussed, the Agency is currently preparing a technical guidance document
for conducting lead-based paint activities. Additionally, it is possible that the Agency may
amend the regulation with more detailed standards in the future, if there is a need to do so.
One reason commenters suggested that the Agency not require certain inspection
techniques is that such requirements often have the effect of discouraging the development of
emerging or new technologies. For example, the Agency currently does not recommend that
chemical test kits be used for lead-based paint testing (Ref. 8). However, EPA recognizes that at
some point in the future, test kit technology is likely to be improved so that the kits can provide
reliable test results. At that time, the Agency will be able to recommend chemical test kits for
testing for the presence of lead in paint.
Two other key issues raised by commenters were: (1) Potential limitations of the
proposed procedures for conducting an inspection, assuming that an inspection involves the
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investigation for lead-based paint throughout an entire residential dwelling or child-occupied
facility, rather than a "partial inspection" of just one or more rooms in a residential dwelling or
child-occupied facility; and (2) the standard contained in Section 745.227(b)(2), which requires
the testing of all components of a residential dwelling or child-occupied facility with a "distinct
painting history," yet allows inspectors not to test those components determined by the inspector
or risk assessor as having been replaced after 1978.
1. Partial inspections. The Agency recognizes that there may be a demand for
lead-based paint identification services that do not involve a surface-by-surface investigation for
the presence of lead-based paint throughout an entire residential dwelling or child-occupied
facility. For example, a homeowner may only be interested in determining if lead is present in
the paint in a child's bedroom, not necessarily the entire residential dwelling. In this instance, it
is unlikely that the homeowner will want to pay for an inspection, as defined under today's
regulations. Although not required, the Agency recommends that a certified inspector or risk
assessor be used in cases, such as these, where an individual or firm believes it is only necessary
to conduct a "partial inspection" of a property.
More specifically, in response to commenters on this issue, the Agency believes that the
definition of an inspection, which under Section 745.227(b) requires that testing for lead-based
paint take place throughout an entire residential dwelling or child-occupied facility, is
appropriate for several reasons.
One reason is that the statutory definition of an inspection in section 401(7) of TSCA
calls for a "surface-by-surface investigation to determine the presence of lead-based paint and the
provision of a report explaining the results of the investigation." As discussed in the September
2,1994 proposal, the Agency believes that an inspection is intended to provide a comprehensive
inventory of all lead-based paint in a residential dwelling or child-occupied facility. As such, the
Agency acknowledges, that the value of a lead-based paint inspection may appeal only to those
individuals interested in getting a complete report on painted components in a residential
dwelling or child-occupied facility. Although it is difficult to predict, the Agency believes that
such a report may be of value to property owners or managers of large multi-family dwellings
and child-occupied facilities and home buyers.
Furthermore, the Agency notes that its inspection requirements are consistent with
general trends in the housing market, particularly in federally-owned housing or housing
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receiving federal assistance. That is, inspections are being conducted to ensure that building
owners are informed of the presence of lead-based paint throughout a residential dwelling or
child-occupied facility, not just one or two rooms.
Lastly, the Agency believes that by establishing requirements only for'"whole house"
inspections it will help ensure that the information needed to determine whether lead-based paint
is present in a residential dwelling or child-occupied facility is accurately presented. Again, the
Agency recognizes that an inspection, as defined under today's final rule, may not provide a
value to all persons. Nonetheless, the Agency believes that by requiring that an inspection be
conducted throughout a residential dwelling or child-occupied facility it will ensure that a person
contracting for the inspection will obtain accurate and reliable information regarding the
presence of lead-based paint throughout a residential dwelling and child-occupied facility.
2. Distinct painting history. On the issue of inspecting and sampling all components
sharing a distinct painting history, except those components replaced after 1978, there are several
points that commenters raised. First, some commenters suggested that the proposed requirement
to take one sample per component in every room and one sample per exterior component with a
distinct painting history was overly burdensome in that it required taking an excessive number of
samples. The assumption of these commenters was that an inspection requires that each and
every painted component throughout a residential dwelling had to be individually tested. The
Agency would like to clarify that an inspection does not necessarily require that a large number
of paint samples be taken.
To clarify this point, the Agency directs commenters to carefully review the definitions of
"component" and "distinct painting history" as contained in Section 745.223 of today's final rule.
According to these definitions, in a room with four walls painted at the same time with the same
paint, only one paint sample would need to be taken to characterize the lead content of the paint
on the walls. This is because, although each wall can be considered a separate "component," the
walls share the same distinct painting history. On the other hand, if there were window frames in
the room that had been painted with a different paint than the walls (for example a semi-gloss
instead of a flat), two samples would need to be taken, one from the walls and one from the
windows. As this example demonstrates, the Agency does not believe that an inspection will
involve excessive sampling.
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In contrast, other commenters disagreed with these requirements for an inspection,
suggesting that they would result in insufficient numbers of samples. Based on the definition of
"distinct painting history," these commenters interpreted the proposal to mean that if all rooms in
a residential dwelling had been painted recently with the same paint and in the same color (for
example, a white latex paint), it would be possible for an inspector to take only one paint sample
from the home.
In response, the Agency notes that in this case it would be clear to an inspector that trim,
doors, and windows are usually painted with a different paint type. Determining the distinct
paint history of such components involves not just an examination of the visible top coat, but the
unique layers of paint beneath the surface. A visible examination of these paint layers is easily
accomplished by making a discrete incision into the painted surface.
C. Risk Assessment Activities
TSCA section 401(16) provides that the objective of a risk assessment is to determine,
and then report, the existence, nature, severity, and location of lead-based paint hazards in
residential dwellings through an on-site investigation. The definition also identifies specific
activities that will be employed when conducting a risk assessment, including: (1) The gathering
of information regarding the age and history of the housing and occupancy by children aged 6
years and under, (2) visual inspection, (3) limited wipe sampling or other environmental
sampling techniques, (4) other activity as may be appropriate, and (5) the provision of a report
explaining the results of the investigation. This definition of risk assessment serves as the basis
for the standards and procedures associated with a risk assessment contained in Section
745.227(d).
The risk assessment procedures in today's final rule, as in the proposal, require the risk
assessor to make a recommendation of lead hazard control strategies to address all lead-based
paint hazards identified as a result of the risk assessment. This activity was not enumerated in
the statutory definition, but was added pursuant to TSCA section 401(16), which stated that a
risk assessment may include "other activities" as may be appropriate.
The Agency's reason for adding this requirement was to ensure that the individual or firm
hiring or contracting for the services of a risk assessor was provided with some reliable guidance
on how to respond to the results of a risk assessment.
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]. Lead hazard screen.
Pursuant to TSCA section 401(16), a risk assessment may include "other activities" as
may be appropriate. Based on this language, today's final rule also includes the "lead hazard
screen," as a risk assessment activity. The requirements for the screen are contained in Section
745.227(c). The reason for including a lead hazard screen in the proposal and today's final rule is
to, where appropriate, avoid the costs of conducting a comprehensive risk assessment,
particularly in well-maintained housing and child-occupied facilities constructed after 1960, or in
housing and child-occupied facilities considered unlikely to have significant lead paint, dust or
soil hazards.
The Agency received two comments on the addition of a lead hazard screen as a risk
assessment activity; one commenter noted that the Agency needed to list more explicitly
standards for conducting a lead hazard screen.
The commenters also agreed that the lead hazard screen should focus on determining the
absence of a lead-based paint hazard, rather than the presence of such a hazard and the risks it
may pose to building occupants. In response, today's final rule includes specific procedures and
standards for conducting a lead hazard screen in Section 745.227(c). Furthermore, because the
lead hazard screen employs highly sensitive evaluation criteria and limited sampling, the Agency
believes that these standards will provide the risk assessor with a basis for determining the
absence of lead-based paint hazards.
If any one of the dust samples collected during a lead hazard screen contains a lead level
greater than one-half of the applicable clearance level for the tested component, or if any sampled
paint is found to be lead-based paint, that is an indication, but not a requirement, that the
residential dwelling should undergo a full risk assessment. As discussed subsequently in this
preamble, clearance levels for specific components can be found in the HUD Guidelines and in
EPA's section 403 Guidance, as well as in several State guidance documents.
Clearance levels are used as the basis for determining whether a lead-based paint
abatement has been successfully completed and that a residential dwelling or child-occupied
facility may be re-occupied (if building occupants were relocated during an abatement).
Currently, under the section 403 Guidance, clearance levels for dust also serve as the levels for
determining the presence of lead-contaminated dust, which may pose a lead-based paint hazard.
A standard for the lead hazard screen of one-half of the applicable clearance levels is extremely
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stringent. As such, the Agency believes that a dust sample containing less than that level is a
reliable indicator that there are no lead-based paint hazards. The work practice standards and
evaluation criteria for a lead hazard screen contained in Section 745.227(c) are modeled after the
HUD Guidelines recommendations for conducting a lead hazard screen.
As discussed previously in the preamble, the Agency recommends that the lead hazard
screen be used primarily in well-maintained homes constructed after 1960. According to HUD,
it is estimated that approximately 37 million privately owned homes and 428,000 public housing
units, or roughly 90 percent of the nation's housing stock built prior to 1960, contain lead-based
paint. Generally, if maintenance has been deferred on these homes, there is a high probability for
the presence of some deteriorated lead-based paint and/or lead-contaminated dust. Consequently,
the value and any cost savings that may be achieved by conducting a lead hazard screen in poorly
maintained, pre-1960 homes, rather than a full risk assessment, may not be realized. For
instance, in a pre-1960 home with several components that have deteriorated paint, in practice,
just as many deteriorated paint surfaces will be tested for a lead hazard screen as for a risk
assessment. However, when conducting the lead hazard screen, a risk assessor is not required to
attempt to determine whether those surfaces pose a lead-based paint hazard.
In fact, homeowners and building owners may decide that a lead hazard screen would
merely add time and cost to the evaluation process in properties that would more likely benefit
from a risk assessment. These benefits include a comprehensive report, not only on the existence
of lead-based paint hazards, but also on the nature, severity, and location of those hazards.
Furthermore, the risk assessment also would provide options on how to reduce or eliminate the
lead-based paint hazards.
Other standards and activities required as a part of the lead hazard screen in Section
745.227(c) include: (1) The collection of background information regarding the physical
characteristics of the residential dwelling or child-occupied facility and occupant use patterns
that may cause lead-based paint exposure to one or more children age 6 years and under, (2) a
visual inspection, (3) the sampling of components with deteriorated paint with a distinct painting
history in poor condition, (4) the collection of a minimum of two composite dust samples (one
for floors and one for windows), and (5) the preparation of a report on the results of the screen.
Specifically, Section 745.227(c) requires that in a residential dwelling two composite samples be
taken~one from the floors and one from the windows in rooms where one or more children,
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age 6 and under, are most likely to come into contact with dust. Additionally, in multi-family
dwellings and child-occupied facilities, composite dust samples are to be taken from any
common areas where one or more children age 6 years and under are likely to come into contact
with dust.
2. Risk assessment
In addition to the requirements of a lead hazard screen, the standards for a risk assessment
contained in Section 745.227(d)(3) also involve the collection and review of background
information regarding the physical characteristics of a building, and the occupant use patterns
that may pose a lead-based paint hazard to children aged 6 years and under. More than two dust
samples and soil samples also may be required under Section 745.227(d)(4), (5), (6) and (7),
respectively. Lastly, the risk assessment report must include options for reducing and/or
eliminating lead-based paint hazards.
The requirements contained in Section 745.227(d) of today's final rule differ from those
proposed in September 1994 in that they reflect the Agency's decision to reduce the detail and
specificity of the rule. However, based on the documentation and recordkeeping requirements
for a risk assessment, and the rule's training, certification and accreditation requirements, the
Agency believes that the standards contained in today's final rule will promote reliable, safe and
effective risk assessments.
For example, the proposed rule specified several items of information to be collected as
background information during a risk assessment, including the age of the building and any
additions being evaluated, copies of any previous inspection reports, and a schematic site plan of
the building. In its review of the comments on the proposed rule, the Agency noted that many of
these requirements would be met during the preparation of a risk assessment report. For
instance, among the items to be presented in a risk assessment report, as contained in Section
745.227(d)(10) are: the date of construction of the building, data collected as a result of any
previous inspection or other analyses available to the risk assessor, and the specific locations of
any identified lead-based paint hazards or potential hazards.
In eliminating specific instructions regarding the background information to be collected,
the Agency believes that the standards for conducting a risk assessment have been simplified
without diminishing the reliability, safety, and effectiveness of those standards. This is because
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today's final rule has eliminated the duplicative reporting requirements included in the
September 2,1994 proposal by requiring that the information only be contained in the risk
assessment report.
In addition to these changes, the Agency has slightly modified Section
745.227(d)(10)(xviii), which requires a risk assessor to provide options for eliminating and/or
reducing lead-based paint hazards in the risk assessment report. Under the proposed rule, the risk
assessor would have been required to provide not only options, but to recommend one option
over another and to include a rationale or justification for his or her selected option. The final
rule no longer requires the risk assessor to recommend one option over another, provided the
recommended options are all presented in the risk assessment report.
These changes were largely based on comments urging the Agency to allow the
individual or firm contracting for the risk assessment to select from the options presented in the
report. Although the Agency does not necessarily believe that the proposed requirements would
have forced a building owner to select the option recommended by a risk assessor, the Agency is
willing to provide building owners with more flexibility in reviewing risk assessment reports and
selecting among remediation options.
In response to comments on the latitude a risk assessor is given in determining dust
sampling locations and the extent of paint deterioration, the Agency believes, as discussed in
Unit VIA. of this preamble, that because the risk assessor will be a trained specialist equipped
with the requisite professional judgement needed to evaluate lead-based paint hazards, added
specificity is unnecessary in the rule. The Agency also stresses that due to major differences in
the structure, design and condition, and occupant use patterns of various buildings, it is best not
to identify specific room locations, e.g., kitchen, playroom, bedroom, for the purposes of
sampling dust. Instead, the regulations in Section 745.227(d)(4), (d)(5), and (d)(6) require that
dust samples be collected in rooms and areas where young children are most likely to come into
contact with dust.
Similarly, the final rule clarifies that only deteriorated paint with a distinct paint history
found to be in poor condition shall be sampled for the presence of lead. "Paint in poor
condition" is defined in today's final rule as more than 10 square feet of deteriorated paint on
exterior components with large surface areas; or more than 2 square feet of deteriorated paint on
interior components with large surface areas (e.g., walls, ceilings, floors, doors); or interior or
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exterior components with small surface areas (window sills, baseboards, soffits, trim) on which
more than 10 percent of the total surface area of the component is deteriorated. This
determination is to be made by the risk assessor based on a documented methodology such as the
HUD Guidelines.
As discussed earlier in Unit VII.C. of this preamble, such locations include the playrooms
and bedrooms of children, kitchens, and living rooms, as well as common areas associated with a
residential dwelling or child-occupied facility.
The Agency also reiterates that detailed instruction on where and how to sample dust is
included in the HUD Guidelines, existing EPA guidance and various State regulations and
guidance documents, and that these instructions will be taught in accredited training programs
and included in future Agency guidance.
Lastly, the Agency has clarified the standards for collecting soil samples contained in
Section 745.227(d)(7) such that samples need only to be taken from exterior play areas and
dripline/foundation areas where bare soil is present. This requirement is in keeping with the
statutory definition of lead-contaminated soil, which basically is the same definition used in
today's final rule. As defined in Section 745.223, lead-contaminated soil means bare soil on
residential real property and on the property of a child-occupied facility that contains lead at or in
excess of levels determined to be hazardous as identified by the EPA Administrator pursuant to
TSCA section 403. Guidance on how to collect bare soil samples is provided in EPA's
Residential Sampling for Lead: Protocols for Dust and Soil Sampling document and the HUD
Guidelines.
D. Composite Sampling
Under today's final rule, composite dust and soil sampling is expressly permitted for the
purposes of conducting a lead hazard screen, risk assessment, or clearance following an
abatement.
This change from the September 2,1994 proposal is based on comments the Agency
received in support of composite sampling for dust and soil, as well as limited evidence
supporting the use of composite dust and soil sampling to determine the presence of lead in dust
and soil. The Agency also believes that composite sampling is useful.because it provides a
means for "averaging" the potential for exposure to lead-based paint hazards in a residential
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dwelling or child-occupied facility. Furthermore, the Agency is permitting use of the technique
due to laboratory cost savings generated by sampling analysis.
However, it is important that the individual who is receiving the results of a composite
understand their limitations and can correctly interpret the results of a composite sample. A brief
discussion of this subject can be found in this section, and a thorough discussion of this issue is
contained in the HUD guidelines, and will be presented in the risk assessor and supervisor
course.
Specific instruction on the taking of composite dust and soil samples is provided in the
HUD Guidelines. The technique essentially involves combining several subsamples from the
same types of components into one sample for analysis. A composite dust sample is different
from a single-surface sample because it combines at least two dust samples from more than one
sampling area into one sample.
Pursuant to Section 745.227(g) of today's final rule, composite dust samples must consist
of at least two subsamples. At this time the Agency recommends that a composite sample
consist of no more than four subsamples, unless the laboratory contracted to analyze the
composite sample agrees to accept a sample consisting of more than four subsamples. This
recommendation is based on current limitations in the laboratory analysis of composite samples
consisting of more than four subsamples (i.e., using available technology, composite samples
that combine more than four subsamples are difficult to properly analyze). However, because
some EPA-recognized laboratories are acquiring the ability to analyze composite samples
consisting of more than four subsamples, the final rule does not explicitly restrict a composite
sample from containing more than four subsamples.
Pursuant to Section 745.227(g) of today's final rule, composite dust samples shall not
consist of subsamples from more than one type of component. For example, subsamples from
four uncarpeted floors from four rooms may be combined into one composite sample. However,
in these same four rooms, the rule prohibits two subsamples from windows in two of the rooms
from being composited with two subsamples from floors in the other two rooms. This restriction
is due to the varying levels of lead that may be present on different components, and the potential
hazard that a component may present. For example, dust samples from floors generally tend to
indicate a lower level of contamination, while the frequency of contamination is generally higher
in windows. Consequently, the interpretation of the results from a composite sample consisting
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of subsamples from different components would not adequately characterize the location of the
hazard. One of the primary benefits derived from composite sampling is lower sampling costs
due to fewer laboratory analyses. Lead levels generally vary significantly from one component
to another, and a single surface sample from one component alone (i.e., from one area of a floor
in a room to another of the same floor) may not represent the potential for exposure. Composite
sampling provides a means to determine potential exposures to lead-based paint hazards by
obtaining a wide cross-section of possible exposure pathways. However, composite sampling
may yield laboratory results that are not as informative as single-surface sampling. For example,
dust samples from the floors of three rooms might be composited where only one of the floors
contains lead-contaminated dust higher than the clearance level contained in the section 403
Guidance for uncarpeted floors of 100 ng/ft2. This might cause the composited sample to fail
clearance. On the other hand, if three single-surface floor dust samples were taken for clearance
testing, the laboratory analyses would have precisely indicated which one of the three rooms
exceeded the clearance level, and the inspector or risk assessor would know exactly which room
needed to be recleaned and retested. Because of these limitations, it is imperative that a risk
assessor, inspector, or supervisor understands and correctly interprets composite samples.
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APPENDIX B
Summary of the Activities of a Risk Assessor
As Specified in the Risk Assessor Curriculum
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APPENDIX B
Summary of the Activities of a Risk Assessor
As Specified in the Risk Assessor Curriculum
B1.0 BACKGROUND AND OBJECTIVE
This document provides a summary of the activities a risk assessor performs for
inspections, lead hazard screens, risk assessments and risk assessments/inspections, as described
in the Section 402 rule. Though the emphasis is on a risk assessment, discussions of the other
activities are also provided.
The information provided will help guide the following tasks:
a. Development of forms to evaluate the costs of inspections, hazard screens, risk
assessments, risk assessments/inspections, and elevated blood-lead investigations.
b. Statistical analysis of the effectiveness of a risk assessment or lead hazard screen
given the choices of a risk assessor.
Table A-l provides a very brief summary of the purpose, scope, and consequence of the
inspection, lead hazard screen, risk assessment and risk assessment/inspection documented in
Section 402 [2] and the student manual for the lead-based paint risk assessment model
curriculum [1] being used to train risk assessors.
It should be noted that this document focuses on current guidance and protocols as
promulgated in the Section 402 rule [2], the Section 403 guidance [3], the HUD Guidelines [4],
and the model training curriculum for risk assessors [1]. Promulgation of the Section 403 rule,
which will identify conditions that result in a lead based paint hazard, may affect the guidance
and sampling recommendations that are summarized in this document. Note that a good portion
of the information listed was extracted from the "Lead-Based Paint Risk Assessment Model
Cirriculum [1]." Additional information to clarify the curriculum was extracted from the Section
402 rule [2], the Section 403 guidance [3], and the HUD Guidelines [4].
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B1.1 DEFINITIONS
There are several terms which will be used throughout the discussion. To avoid
misinterpretations the definitions of the terms are provided below.
• A RISK ASSESSMENT is an on-site investigation of a residential dwelling for
lead-based paint hazards. Risk assessments include investigating the age, history,
management, and maintenance of the dwelling; conducting a visual assessment;
performing limited environmental sampling, such as dust wipe samples, soil
samples, and deteriorated paint samples; and reporting the results that identify
acceptable abatement and interim control strategies based on specific conditions and
the owner's capabilities.
• An INSPECTION is a surface-by-surface investigation for determining the presence
of lead-based paint.
• A LEAD HAZARD SCREEN is an alternative to a risk assessment that involves
limited paint and dust sampling in homes in relatively good condition.
• LEAD-BASED PAINT is any paint or other surface coatings that contain lead equal
to or in excess of 1.0 mg/cm2 or more than 0.5 percent by weight (5,000 ug/g, 5,000
ppm, or 5,000 mg/kg).
• LEAD BASED PAINT HAZARD is a condition in which exposure to lead from
lead-contaminated dust, lead-contaminated soil, deteriorated lead-based paint, or
from lead-based paint present on accessible, friction, or impact surfaces that would
result in adverse human health effects.
B.1.2 OVERVIEW OF THE LEAD HAZARD EVALUATION PROCESS
For single family housing, one or more of the following steps may have to be completed
prior to a risk assessment or other evaluation.
1. Provide information to the owner about lead hazards and how they can be evaluated.
2. Help owner determine the type of activity that should be conducted-risk assessment,
inspection, lead hazard screen, or risk assessment/inspection.
3. Discuss the history of the property and the future plans of the owner, resources, and
occupants.
4. Set up visual inspection of the property, plan for environmental sampling, and set up
analysis of samples by an EPA-recognized laboratory.
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o
I
Table B-1. Purpose, Scope, and Consequences of an Inspection, Lead Hazard Screen. Risk Assessment, Risk Assessment/
Inspection and EBL Investigation
o
o
z
CD
o
o
o
I
5-'
i
Lead Hazard Screen
• Risk Assessment
Risk'Assessment/Inspection
Purpose
Attempts to find
out which surfaces
have lead-based
paint.
Conducted on housing in
good condition as defined by
HUD guidelines. Determines
if a full risk assessment is
needed.
To determine and then to
report the existence, nature,
severity, and location of
lead-based paint hazards in
housing through an on-site
investigation and the
possible means of correcting
any hazards identified by
surveying likely sources
including soil, dust, and
paint.
To determine where the
lead-based paint in a
dwelling is located and
where lead-based paint
hazards are located.
Scope
Focuses on
identifying the
presence or
absence of lead-
based paint on all
surfaces.
Focuses on determining if
the property needs to have a
full risk assessment or if the
property does not have lead-
based paint hazards and
needs no action.
Focuses on the likely lead-
based paint hazard at the
property that the client
owns or resides in.
Combines a surface-by
surface measurement of lead
based paint with soil and
dust sampling to provide the
owner with information on
what should be done
immediately and what can
be done later.
Consequences
31
0)
Cl
CO
(O
CO
Allows the
property owner to
classify all painted
surfaces as either
LBP or non-LBP.
Property owner may need to
have a full risk assessment
if property may have lead-
based paint hazards.
The property owner has
authority to make decisions
about the lead hazard
control options taken.
However, some states and
localities may have certain
provisions.
The property owner receives
information to know what
should be done immediately
and what can be done later.
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5. The risk assessor must identify the most appropriate strategies for a specific
property. The risk assessor should discuss motivating factors and review these with
the property owner:
Legal or insurance requirements;
Property disposition (sale or turnover)
Liability issues
Preventive measures for children at risk
Preventive measures prior to renovation or remodeling
Response to a child with elevated blood lead levels
Cost.
Once the necessary steps outlined above have been completed one or more of the following steps
may be necessary.
1. Determine whether a risk assessment, inspection, a combination risk
assessment/inspection, or a lead hazard screen should be conducted.
2. Get background information on the dwelling, owner's plans, resources, and
occupants (if present).
3. Arrange a date to do the visual examination and environmental sampling. Make any
necessary arrangements with the owner to notify residents. Some education on why
this work is being done may be necessary, especially if an inspection has already
been done.
4. Conduct environmental sampling, and send samples to an EPA-recognized
laboratory.
5. Combine visual findings with environmental sampling results, and determine if
hazards are present.
6. Provide owner with a range of options to control any hazards found, along with
rough, estimated costs and reevaluation schedules.
7. Document all findings and determinations in a standard report.
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B2.0 RISK ASSESSMENT
The purpose of a risk assessment is to uncover only housing-related lead-based paint
hazards by surveying likely sources. Activities included in a risk assessment are a visual
examination of the property, collection of dust, soil, and paint samples, and the writing of a risk
assessment report. Discussed below are the specifics of each of these activities.
B2.1 VISUAL EXAMINATION
The purpose of the visual examination is for the risk assessor to locate and assess
potential lead-based paint hazards and their causes.
The visual examination evaluates:
• deteriorated paint and visible causes of such deterioration;
• visible dust accumulation;
• areas of bare residential soil;
• painted surfaces that are either impact points or subject to friction;
• painted surfaces where a child's chewing is suspected.
The focus should be on locating current visible lead hazards. The risk assessor locates
lead-based paint hazards by locating areas where paint, dust, and soil may be hazardous and by
conducting environmental sampling. If paint on certain components is known through other tests
or other information not to contain lead at or above the regulatory limit, it is not necessary for the
risk assessor to evaluate its condition.
The exterior visual examination should address the roof; windows; porches; masonry and
foundations; other painted surfaces and bare residential soil. The interior visual examination
should address the attics; drop ceilings; windows; doors; baseboards and moldings; stairs and
floors; plumbing; and the basement.
During a visual examination walk-through the following should be taken into
consideration:
1. Determine the exterior and interior condition of the building.
2. During the walk-through survey the risk assessor should determine:
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a. If the property is in good repair or if there are significant structural or moisture
problems (cracks in walls, sagging walls, holes in the roof, and extensive water
stains.
b. Does the property have large amounts of deteriorated paint and/or visible dust
accumulation?
Paint deterioration may be categorized as:
1) Surface-coat failure - top layer of paint flaking, peeling or otherwise
detaching from layers below;
2) Multi-coat failure - several top layers of paint or other coatings (e.g.,
wallpaper) are delaminating from layers below;
3) Paint failure revealing unsound substrate or structure - paint delamination
reveals the substrate or underlying structure is unsound (e.g., rotted wood or
plaster off lathe);
4) Paint abrasion - paint is rubbing because of mechanical friction (e.g.,
windows) or from human contact (e.g., painted stairs and floors scuffed by
walking or other contact);
5) Chinned paint - pieces of paint are loosened or broken because of impact
(e.g., doors, baseboards, or chair rails).
c. Are the windows and doors old and possibly coated with lead-based paint; are
the windows and/or doors relatively new and hence unlikely to be coated with
lead-based paint; and are the window and door tracks generally painted and/or do
the troughs contain chips and dust?
d. Is there any obvious exterior source of lead (old house next door that has lots of
peeling paint or battery recycling shop that is located nearby)?
e. Determine the property's recent maintenance history.
B2.2 EMVIRONMFNTAL SAMPLING
In order to evaluate lead hazards the collection of dust, soil, and paint samples is
necessary. The specifics of sampling are presented in this section by media.
Note that all laboratories used to do environmental sampling analysis in a risk assessment
should be recognized as proficient through one of the accrediting organizations in the EPA
National Lead Laboratory Accreditation Program (NLLAP).
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B2.2.1 Dust
For children, dust is an important pathway of exposure to lead. Studies have shown that
dust lead levels are among the strongest predictors of children's blood-lead levels compared with
a number of other variables.
Units of Measure of Lead in Dust
Lead in dust can be measured by loading (area concentration), a measure of the total
amount of lead present in micrograms of lead per square foot of surface area (ug/ft2), or by mass
concentration, a measure of the amount of lead contained in dust expressed as micrograms of
lead per gram of dust (ug/g). Loading is measured directly by wipe sampling and vacuum
sampling. Mass concentration is usually measured by vacuum sampling and cannot be measured
by the standard wipe sampling methods. Wipe sampling is the recommended method for routine
risk assessments for the following reasons:
• It is relatively simple and inexpensive
• It has been correlated with children's blood lead levels in a number of studies;
• Current EPA, HUD, and state standards are based on wipe sampling;
• Vacuum sampling methods are not standardized;
• Since there are no concentration standards, it is not possible to identify hazards using
vacuum sampling.
EPA Guidance Levels for Dust
The following interim guidance (July 1994) should be used for lead risk assessment until
the permanent health-based standards defining "dangerous levels of lead in house dust" are
determined as required of EPA through Title X legislation:
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Floors (Bare) 100 ug/ft2 (as determined by wipe sampling only)
Interior window sills (stools) 500 ug/ft2 (as determined by wipe sampling only)
Window troughs (wells) 800 ug/ft2 (as determined by wipe sampling only)
Dust samples can be taken as single samples or composite samples. Composite samples
have the advantage of being lower in cost per surface sampled and an increased surface area can
be wiped for about the same analysis cost. The disadvantages of using composites are that
information on a specific sampling location is lost and laboratories have to adopt special
handling and digestion procedures. If composite samples are used, a minimum of three separate
composite dust samples should be collected. The composite samples should be collected from
bare floors or carpeted floor for wall-to-wall carpets, window sills, and window troughs.
The following are rules for composite sampling:
1. No less than 2 and no more than 4 individual wipes should be included in each
composite sample.
2. Separate composite samples are required from carpeted and hard surfaces (e.g., a
single composite sample should not be collected from both carpeted and bare floors).
Whenever possible, hard floors should be sampled instead of carpets. Collection
efficiencies may vary considerably on carpets.
3. Separate composite samples are required from each different component sampled
(e.g., a composite sample should not be collected with both floor and window sill
subsamples contained in one composite sample).
4. Separate composite samples are required for each dwelling.
5. Floor surface areas sampled in each room should be approximately the same size
(1ft2 or 929 cm2). Window trough and interior window sill sampling sizes are
dependent on window characteristics but should be as similar as possible from room
to room (e.g., the surface sampling area should not be skewed so that one room is
over sampled.
6. The same wipe should not be used to sample two different spots. A new wipe should
be used for each spot sampled.
7. When composite samples are submitted for analysis blank and spike (control) quality
assurance/quality control samples should also be included and analyzed.
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Single-surface samples should be used:
1. when information is needed to determine leaded dust levels in a specific location.
For example, pet sleeping areas, porch areas, laundry areas where contaminated
clothing is washed, or lead hobby areas;
2. in other areas where leaded dust levels are expected to be high to determine if
targeted cleaning efforts are needed.
Composite samples should be used:
1. when controlling costs is essential;
2. when there is no reason to suspect that dust levels from the same types of surfaces in
different rooms will vary greatly;
3. when the costs of multiple-room clean-up will not greatly exceed the cost of single
room clean-up.
The Number and Location of Samples
A. For composite samples, the following rooms should be sampled (at a minimum):
1. principal play room for children (TV room, living room, or dining room);
2. kitchen;
3. bedroom of the youngest child;
4. bedroom of the next oldest child.
In vacant dwellings substitutions may be made such as, the living room for the play
room and smallest bedroom for the youngest child's room.
B. For single-surface samples at least 6-8 samples are necessary for evaluating the
hazards in each dwelling.
Children are most likely to come in contact with dust in
1. the entry way (including porches)
2. child's principal play area (TV room, living room, or dining room)
3. children's bedrooms, kitchen, and bathroom.
Within these rooms, areas that are likely to have high dust levels include:
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1. floors near friction or impact spots, or areas with deteriorated paint
2. interior window sills (of frequently opened windows)
3. window trough (of frequently opened windows) and
4. cabinet with deteriorated paint (housing dishes, toothbrushes, eating
utensils, etc.)
B2.2.2 Soil
Several studies have shown that soil contaminated with lead contributes significantly to
the blood-lead levels found in children. Exposure occurs through direct ingestion of soil, track-in
of soil into the interior of the house, or through a combination of the two. Soil may be
contaminated with lead from several sources (1) weathering and "chalking of lead-based paint on
the building's exterior, (2) nearby demolition or renovation activities, (3) previous repainting
jobs involving scraping of exterior lead-based paint, (4) airborne contamination from the
emissions of engines burning leaded gasoline in past years (although leaded gasoline has been
generally phased out under the EPA ban much lead entered the environment from this source up
until the late 1980s, and (5) point sources of airborne lead such as lead smelters and battery
manufacturing plants.
Children become exposed to lead when they get their hands dirty in soil and put their
fingers or other objects into their mouths. Lead contaminated soil is also a potential source of
lead in interior house dust, since residents and their pets can easily track soil into the dwelling.
Also, vegetables grown in lead contaminated soil may take up lead and be ingested by the
residents of the dwelling. As a result, testing of bare soil around a dwelling and in play areas is
required for lead-based paint risk assessments.
Units of Measure of Lead in Soil
Soil lead levels are usually expressed in micrograms of lead per gram of soil (ug/g). This
is equivalent to milligrams per kilogram (mg/kg) or parts per million by weight (ppm). Some
laboratories may report concentration in weight percent which can be converted to ug/g or
mg/kg.
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EPA Guidance Levels for Soil
Until health based standards are developed, EPA guidance states the following levels of
concern.
Bare Soil Lead Concentration (ppm):
400 ppm - Areas expected to be used by children,
including residential backyards, daycare,
and school yards, playgrounds, public
parks, and other areas where children
gather.
2,000 ppm - Areas where contact by children is less likely or
infrequent.
5,000 ppm - Abatement of soil required regardless of the expected
contact by children.
Soil Sampling
In order to reduce variability and costs, all routine soil samples collected for lead-based
paint risk assessment purposes are composite samples. One composite sample is taken from the
child's play area if it can be identified and a second from the building foundation. Soil samples
are taken by (1) coring or (2) scooping. Composite samples should consist of 3-10 subsamples.
Other areas that may be sampled are gardens, pet sleeping areas, parking areas possibly
contaminated from vehicle exhaust, or sandboxes. Samples taken along the building foundation
should be 2-6 feet apart. If there is no bare soil then sampling is not necessary. This includes
areas where all soil is covered by pavement or thick grass cover, ivy, or similar material. In most
cases there are some areas that should be sampled. If paint chips are present in the soil, they
should be included as part of the soil sample but no special attempt should be made to
oversample paint chips.
B2.2.3 Paint
In a risk assessment previous paint testing results should be reviewed to be sure the
owner can rely on the data to determine which surfaces have lead-based paint and which do not.
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Interim Guidelines for Paint
The federal standards for lead-based paint are 1.0 mg/cm2 or 5,000 ug/g (equivalent to
5,000 ppm, 5,000 mg/kg, or 0.5 percent by weight).
Paint Sampling
Deteriorated paint means paint that is cracking, flaking, chipping, peeling, or otherwise
separating from the substrate of a building component. All deteriorated paint films should be
measured to determine if they contain levels of lead at or above the applicable limit. If there are a
large number of surfaces with deteriorated paint, it may be best to complete an inspection since
the added expense is not great.
Risk assessments usually need to measure 2-10 paint films. Paint films can be
composited to help reduce cost especially if it is likely that none of the paint films is above the
applicable standard. The laboratory doing the analysis must have special capability to do this
type of assessment. Since a number of samples are combined, the results will indicate whether or
not any of the surfaces sampled could be over the limit. If the analysis is positive then only
analysis of single surface samples can determine exactly which samples are over or under the
limit. The risk assessor should collect duplicate samples to avoid having to make a return trip to
the house.
Intact paint, on friction, impact, or accessible or chewable surfaces need not be measured
for lead. The lead hazards associated with these surfaces are determined through dust analysis
and visual inspection, not through XRF or paint chip analysis.
The lead content in deteriorated paint films should be determined by using either portable
XRF analysis of deteriorated paint or laboratory analysis of paint chips. Protocols for these
analyses are available from EPA, HUD, and ASTM. XRF may be more cost effective than
laboratory analysis of chips especially if the dwelling has a large number of deteriorated surfaces.
Current Chemical Spot Test Kits are not recommended as a method to measure lead in
deteriorated paint.
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Sampling Locations
The risk assessor should select an unobtrusive area (behind pictures, behind furniture,
near comers, underneath protruding surfaces (mantels, window sills) to take paint film samples
where
• all paint films are present,
• there is the least deterioration, and
• the smallest possible substrate is included with the paint sample.
When several layers of paint are present on a surface, all layers of paint should be
sampled. The following are reasons why all layers should be sampled.
• No additional cost is incurred by sampling all layers, and if currently intact layers
peel in the future, repeated sampling will not be required.
• The information helps the owner plan future activity even if the layers with lead are
now intact.
• No available technology can clearly distinguish which layers contain lead and which
do not.
• The presence of deteriorated paint is an indication that other layers are more likely to
fail in the future.
• Repairing deteriorated layers will usually involve some abrasion of the intact layers
below, possibly resulting in a dust hazard.
• Different methods of paint analysis will be consistent only if all layers are analyzed
(e.g., XRF, which measures all layers of a surface, will produce different results
from laboratory paint chip analysis if the latter includes only some of the layers).
B2.2.4 Other Media
The risk assessment may also include the evaluation of lead in water or other components
of multiple family dwellings, etc. (The present study is not concerned with these data and this
summary does not include information on these entities.)
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B2.3. RISK ASSESSMENT REPORT
The risk assessment must also include a risk assessment report which (1) summarizes the
results by indicating where hazards are found; (2) indicates the range of hazard control options
likely to be effective (indicating ongoing monitoring and maintenance of each option); (3)
includes all raw data and identifying information; and (4) in some jurisdictions may become a
legal document.
The risk assessment report includes a section on identifying information; a section on
completed management, maintenance and environmental results forms and analysis; and a
section on lead hazard control plan. The risk assessor must make clear to the owner that the
choice of how to control the hazard is up to the owner, not the risk assessor.
The four functions of the final risk assessment report are:
1. It summarizes the results of the risk assessment indicating where hazards are found.
2. It indicates the range of hazard control options likely to be effective.
3. It includes all raw data and identifying information.
4. It may become a legal document in some jurisdictions.
When the results of any environmental sampling are above the guidance levels listed
earlier, the dwelling fails the risk assessment. When all samples are below the lead hazard screen
guidance levels, the dwelling is considered to be free of lead-based paint hazards. Only a full
paint inspection determines for sure if the dwelling is lead-free. The risk assessor should provide
the owner with documentation of the screening and the negative finding. The risk assessor should
make sure that the results of the screen are sufficient to satisfy local or insurance standards
before signing any certificates of a lead hazard status that may be requested by an owner.
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B3.0 LEAD HAZARD SCREEN
A lead hazard screen, where appropriate, avoids the costs of conducting a comprehensive
risk assessment, particularly in well-maintained housing and child-occupied facilities constructed
after 1960, or in housing and child-occupied facilities considered unlikely to have significant
lead paint, dust or soil hazards.
The lead hazard screen should focus on determining the absence of a lead-based paint
hazard, rather than the presence of such a hazard and the risks it may pose to building occupants.
In the lead hazard screen a visual inspection is conducted. Deteriorated paint is sampled
and two composite dust samples are collected, one from the floor and the other from the window
troughs in locations where one or more children, age 6 and under, are most likely to come in
contact with dust. Paint and dust samples are analyzed. A hazard screen report and
recommendations if appropriate are provided for the owner. See Table A-2 for a comparison of
the lead hazard screen with a full risk assessment and a paint inspection.
Draft Report - Do Not Quote. Cite. Copy or Distribute February 15, 1999 B-16
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B4.0 LEAD-BASED PAINT INSPECTION
Lead-based paint inspections can be performed by either a certified inspector technician
or a certified risk assessor. Inspections measure the concentration of lead in paint on a surface-
by-surface basis. Inspections results enable the owner to manage all lead-based paint, since the
exact locations of the lead-based paint have been identified. However, the inspection does not
determine whether the paint presents an immediate hazard. The collection of dust and soil
samples is not part of a routine paint inspection. Thus, if a risk assessment is not performed
along with the paint inspection, a full determination of the location and natures of all lead-based
paint hazard cannot be made. In addition, no hazard control measures can be suggested by the
inspector.
A paint inspection is the preferred evaluation method when an owner has decided to abate
all lead-based paint or when there is a low expectation of the presence of lead-based paint.
Inspections are also appropriate when extensive renovation that is about to occur will disturb
painted surfaces.
The recommended method for measuring the lead level in paint is with a portable XRF
instrument manufactured for paint analysis. The use of paint-chip sampling and laboratory
analysis is secondary because it is time-consuming, costly, and requires extensive repairs of
painted surfaces. In a residential dwelling and child occupied facility, each component with a
distinct painting history and each exterior component with a distinct painting is tested for lead-
based paint, except those components known to have been replaced after 1978, or do not contain
lead-based paint. Paint is defined to be lead-based if the lead content equals or exceeds either 1.0
mg/cm2 or 0.5% by weight. An inspection report is prepared to include all the relevant
information, i.e., method of testing, locations, the results of the inspection in terms of the
appropriate sampling method. See Table A-2 for a comparison of activities that must be
performed for a lead-based inspection with the activities in a lead hazard screen and a risk
assessment.
Draft Report - Do Not Quote, Cite, Copy or Distribute February 15, 1999 B-17
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Table B-2. Comparison of a Lead Hazard Screen, a Risk Assessment, and a Paint Inspection
Visual Inspection
Paint
Dust
Soil
Water
Air
Paint Guidance Level
Dust Guidance Level
Soil guidance Level
Housing Condition
Use Patterns
Assessment
Management and
maintenance data
•- • * r*-"£ ' x Lead Hazard Screen - -.'.": ''.''*•
Yes
Deteriorated Paint Only
2 Composite
1 . Floor (entry way) from 1st child's bedroom,
2nd child's bedroom, children's principal
play area, additional location
2. Window trough from 1 st child's bedroom,
2nd child's bedroom, children's principal
No
No
No
1 .0 mg/cm2 or 5,000 ppm or 0.5%
floors = 50/yg/ft1
window troughs = 400 jug/ft2
None determined
Yes
No
No
* Full Risk Assessment . .:
Yes
Deteriorated Paint Only
3 or 4 Composite
1 Uncarpeted floor (include
entryway)
1 Window sill
1 Window trough
Or 6-8 single surface
2 Composite
1 Foundation
1 Play areas
Optional
No
1.0 mg/cm2 or 5,000 ppm or 0.5%
floors = 100j/g/ft2
window sills = 500 jig/ft2
window troughs = 800 j/g/ft2
400 fjglg high contact
2,000 fjglg residential yard
5,000 /jglg permanent abatement
Yes
Yes
Optional - depends on property type
,1 Paint' Inspection- - - ||
Yes II
Surface-by-Surface ||
Optional
Optional
Optional
No
1 .0 mg/cm2 or 5,000 ppm or
0.5%
Same as risk assessment if II
conducted II
Same as risk assessment if II
conducted
Not Required
No
No I
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-------
B5.0 RISK ASSESSMENT/INSPECTION
It is sometimes advisable to conduct a risk assessment and paint inspection. By
combining measurements of soil and dust with surface-by-surface paint analysis, and collecting
maintenance and management data, lead-based paint hazards can be identified in a
comprehensive fashion and addressed appropriately.
Draft Report - Do Not Quote, Cite, Copy or Distribute February 15, 1999 B-19
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B6.0 REFERENCES
[1] Lead-Based Paint Risk Assessment Model Curriculum prepared, 1995 for the U.S.
Environmental Protection Agency, Chemical Management Division.
[2] U.S. Environmental Protection Agency, "Lead: Requirements for Lead-Based Paint -
Activities in Target Housing and Child-Occupied Facilities, Final Rule", Memorandum
Federal Register, pp. 45777-45830, August 29,1996.
[3] U.S. Environmental Protection Agency, "Guidance on Identification of Lead-Based Paint
Hazards", Memorandum Federal Register, pp.47248-47257, September 11,1995.
[4] U.S. Department of Housing and Urban Development, "Guideline for the Evaluation and
Control of Lead-Based Paint Hazards in Housing," Office of Lead-Based Paint
Abatement and Poisoning Prevention, HUD-1539-LBP, July 1995.
Draft Report - Do Not Quote, Cite. Copy or Distribute February 15, 1999 B-20
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APPENDIX C
Risk Assessor Cost Questionnaire
Draft Report - Do Not Quote. Cite. Copy or Distribute February 15. 1999 C-1
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-2-
COST EVALUATION OF LEAD RISK ASSESSMENT, LEAD HAZARD SCREEN,
INSPECTION, AND RISK ASSESSMENT/INSPECTION
INFORMATION TO BE FILLED IN PRIOR TO MAKING PHONE CALL
DATE. PARTICIPANT ID:
NAME OF COMPANY:
STREET ADDRESS: •
CITY: STATE:L_U ZIP; I Mill-Mill
CONTACT PERSON:
POSITION:
TELEPHONE NUMBER
.:(U_Lj)l I I l-l I I I lext..
GREETING
Hello, my name is and l'm Callin9from the Battelle Memorial Institute in Columbus,
Ohio. We are doing a study with the Environmental Protection Agency to assess the capacity of the Section 402 lead risk
assessment protocol to protect the health of children in housing containing lead based paint and to assess the value of
different risk assessment protocols in light of costs. Part of our task involves contacting contractors in various
communities and asking them to participate in a brief evaluation regarding the cost of conducting a lead risk assessment,
lead hazard screen, inspection, or risk assessment/inspection. Would you have 5-10 minutes to answer some questions?
For your participation, you will receive a summary of the results from this survey within 6 months of its completion. The
summaries would allow you to assess how your costs compare to other contractors. Can I ask you the questions?
D Yes
D No
Reason for not participating:
INTERVIEWER:
TOTAL TIME FOR INTERVIEW:
Draft Report - Do Not Quote. Cite, Copy or Distribute February 15. 1999 C-2
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-3-
A. INITIAL CONSULTATION
A1. Do you have a charge for initially coming to a
home to consult with the owner about the
property and whether a risk assessment,
hazard screen, inspection, or risk
assessment/inspection should be conducted?
YES 22%(n=9)
NO {GotoquestionB1} 78% (n=9)
A2. Do you have different consultation fees for
different expected activities?
YES 0% (n=2)
NO {Go to question 81} 100% (n=2)
A3. What are your consultation fees for a:
a. Risk Assessment
(n=OH---)
b. Lead Hazard Screen
c. Inspection
d. Risk Assessment/
Inspection
(n=OH---)
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15. 1999 C-3
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-4-
B. FULL RISK ASSESSMENT
The next few questions are specific to performing a FULL RISK ASSESSMENT only. Assume that you are at the
home to perform the risk assessment.
B1. Do you have a basic fee for performing a full
risk assessment or does your fee depend on
the activities performed?
BASIC FEE INFORMATION
B2. What is your basic fee for a
risk assessment?
B3. a. Is there a Visual Inspection
included in the Basic Fee?
b. What is the additional fee to
perform a Visual Inspection?
B4. a. Is a Risk Assessment Report
included in the Basic Fee?
b. What is the additional fee for the
Risk Assessment Report?
B5. Is Environmental Sampling
included in the Basic Fee?
a. Basic Fee 44%(n=9)
{Go to question B2}
b. Separate Fees for each activity ... 56% (n=9)
{Go to question 810}
$422.50 (n=4)($190-$900)
Yes .... 100% (n=4) {Go to 84}
No 0%(n=4)
--)
Yes .... 100% (n=4) {GotoBS;
No 0%(n=4)
• (n=0) (• - •)
Yes 50%(n=4) ... {GotoB6;
No 50%(n=4) ... {Go to 89J
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15. 1999 C-4
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-5-
B. FULL RISK ASSESSMENT (Continued)
B6. How many and what type of environmental samples are collected for the basic fee (i.e., the average number of
samples collected)?
Medium
a. Soil
b. Dust
Paint
Location
c. Floor
d. Window Sill
e. Window Well
Type of Sample or
Method of Collection (Check)
Scoop
Single Samples
Composite Samples
Single Samples
Composite Samples
Single Samples
Composite Samples
Single Samples
Composite Samples
f. XRF
g. Paint Chips - Single Samples
h. Paint Chips - Composite
Samples
No. of Samples
Collected
3 (n=1)
• (n=0)
(3-3)
(...)
6
(n=2)
(n=0)
(5-8)
(...)
(n=0)
(n=0)
(...)
(...)
(n=0)
(n=0)
(...)
(...)
(n=0)
(n=0)
(...)
(...)
225 (n=1) (200-250)
(n=0)
(n=0)
Water
(n=0)
j. Other Optional Samples
Dust: 6-8
Paint: If needed. If paint peeling, will take a single. Varies. 200-250.
Soil: If needed.
Water: If needed.
B7. If more samples are required, do you have
incremental costs for each additional sample?
Yes 100%(n=2).... {Goto88}
No 0% (n=2) .... {Goto C1}
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 C-5
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-6-
B. FULL RISK ASSESSMENT (Continued)
B8. What are the incremental costs:
Medium
Dust
Soil
Paint
g. Water
Type of Sample
a. Single
b. Composite
c. Composite
d.XRF
e. Paint Chips - Single Samples
f. Paint Chips - Composite Samples
Collection
Cost Per
Sample
•(n=0)
(...)
• (n=0)
(...)
• (n=0)
(...)
•(n=0)
(...)
•(n=0)
(...)
• (n=0)
(._.)
• (n=0)
(...)
Analysis Cost/
Sample
$7.50 (n=2)
($5-$10)
• (n=0)
(...)
$7.50 (n=2)
($5-$10)
• (n=0)
(._.)
$5(n=1)
($5-$5)
• (n=0)
(._.)
$7.50 (n=2)
($5-$10)
Total Cost of
Environmental
Samples
$7.50 (n=2)
($5-$10)
• (n=0)
(...)
$7.50 (n=2)
($5-$10)
• (n=0)
(...)
$5(n=1)
($5-$5)
• (n=0)
(...)
$7.50 (n=2)
($5-$10)
h. Other Optional Samples
(COMPLETED SECTION B — GO TO QUESTION C1)
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 C-6
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-7-
B. FULL RISK ASSESSMENT (Continued)
B9. What are the additional fees for performing environmental sampling?
Medium
Dust
Soil
Paint
g. Water
Type of Sample
a. Single
b. Composite
c. Composite
d.XRF
e. Paint Chips - Single Samples
f. Paint Chips - Composite
Samples
No. of
Samples
4 (n=2)
(3-8)
6(n=1)
(3-8)
2 (n=2)
(1-4)
• (n=0)
(...)
• (n=0)
(...)
• (n=0)
(•-•)
1 (n=D
(1-D
Collection
Cost Per
Sample
$10(n=1)
($10-$10)
$10(n=1)
($10-$10)
$15(n=1)
($15-$15)
• (n=0)
(...)
• (n=0)
(...)
• (n=0)
(•-•)
$15(n=1)
(S15-S15)
Analysis
Cost/
Sample
$15(n=2)
($11-$15)
$15(n=1)
($15-$15)
$12.50 (n=2)
($10-$15)
• (n=0)
(...)
• (n=0)
(...)
• (n=0)
(...)
$12.50 (n=2)
($10-$15)
h. Other Optional Samples
Soil
Single
3 (n=1)
(2-4)
$15(n=1)
($15-$15)
$10(n=1)
($10-$ 10)
Total Cost of
Environmental
Samples
$100 (n=2)
($45-$200)
$150 (n=1)
($75-$200)
$42.50 (n=2)
($15-$120)
• (n=Q)
(...)
•(n=0)
(...)
• (n=0)
(•-•)
$12.50 (n=2)
($10-$15)
$75(n=1)
($50-$100)
(COMPLETED SECTION B — GO TO QUESTION C1)
SEPARATE FEE FOR EACH ACTIVITY
What is the overall cost for
B10. A Visual Assessment
B11. A Risk Assessment Report
B12. Typical Environmental Sampling
$272 (n=5) ($150-$500)
$282 (n=5) ($50-$500)
$260 (n=5) ($41.5041000)
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 C-7
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-8-
B. FULL RISK ASSESSMENT (Continued)
B13. What are the individual environmental sampling costs for
Medium
Dust
Soil
Paint
g. Water
Type of Sample
a. Single
b. Composite
c. Composite
d.XRF
e. Paint Chips - Single
Samples
f. Paint Chips -
Composite Samples
No. of
Samples
11.75(n=4)
(7-25)
2(n=1)
(2-2)
10(n=1)
(10-10)
•(n=0)
(•-•)
27.17 (n=3)
(3-50)
• (n=0)
(...)
1(n=1)
(1=1)
Collection
Cost Per
Sample
• (n=0)
(...)
• (n=0)
(._.)
• (n=0)
(...)
•(n=0)
(...)
• (n=0)
(._.)
• (n=0)
(•-•)
• (n=0)
(...)
Analysis Cost/
Sample
$23.13 (n=4)
($20-$30)
$15(n=1)
($15-$15)
$20 (n=1)
($20-$20)
• (n=0)
(...)
$20.58 (n=3)
($16.50-$25)
• (n=0)
(...)
$15(n=1)
($15-$15)
Total Cost per
Environmental
Samples
$289.69 (n=4)
($140-$750)
$30(n=1)
($30-$30)
$200 (n=1)
($200-$200)
•(n=0)
(...)
$552.58 (n=3)
($55.50-$1000)
•(n=0)
(...)
$15(n=1)
($15-$15)
h. Other Optional Samples
Soil
3 (n=2)
(1-5)
• (n=0)
(...)
$20 (n=2)
($15-$25)
$70 (n=2)
($15-$125)
Dust: Varies depending on home circumstance.
Paint: Varies depending on home circumstance.
B14. If more environmental samples are
required do you have incremental costs
for each additional sample?
Yes ... 100 (n=5) {Goto B15}
No 0 (n=5) {Go to 01}
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 C-8
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-9-
B. FULL RISK ASSESSMENT (Continued)
B15. What are the incremental costs?
Medium
Dust
Soil
Paint
g. Water
Type of Sample
a. Single
b. Composite
c. Composite
d. XRF
e. Paint Chips - Single Samples
f. Paint Chips - Composite Samples
Collection
Cost Per
Sample
• (n=0)
(...)
• (n=0)
(...)
• (n=0)
(...)
• (n=0)
(...)
• (n=0)
(•-•)
• (n=0)
(•-•)
•(n=0)
(...)
Analysis Cost/
Sample
$21.50(n=5)
($15-$30)
• (n=0)
(...)
$20 (n=3)
($15=$25)
• (n=0)
(...)
$20.58 (n=3)
($16.50-$25)
• (n=0)
(•-•)
$15(n=1)
($15415)
Total Cost per
Environmental
Samples
$21.50(n=5)
($15-$30)
•(n=0)
(...)
$20 (n=3)
($15-$25)
• (n=0)
(...)
$20.58 (n=3)
($16.50-$25)
• (n=0)
(•-•)
$15 (n=1)
($15-$15)
h. Other Optional Samples
(COMPLETED SECTION B — GO TO QUESTION C1)
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15. 1999 C-9
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-10-
C. LEAD HAZARD SCREEN
C1. Do you have a basic fee for performing a
lead hazard screen or does your fee depend
on the activities performed?
a. Basic Fee 62%(n=8)
{Go to question C2}
b. Separate Fees for each activity ... 38% (n=8)
{Go to question C10}
BASIC FEE INFORMATION
C2. What is your basic fee for a
Lead Hazard Screen?
$157.50 (n=4)($90-$200)
C3. a. Is there a Visual Inspection included in the Basic Yes
Fee? No .
100% (n=5)
0% (n=5)
to C4}
b. What is the additional fee to
perform a Visual Inspection?
C4. a. Is a Risk Assessment Report included in the Basic Yes
Fee? No .
100% (n=5)
0% (n=5)
{Go to 05}
b. What is the additional fee for the
Risk Assessment Report?
C5. Is Environmental Sampling
included in the Basic Fee?
Yes
No
100%(n=5)...
0%(n=5) ..
{Go to 06}
{Go to 09}
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 C-10
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-11-
C. LEAD HAZARD SCREEN (Continued)
C6. How many and what type of environmental samples are collected for the basic fee (i.e., the
average number of samples collected?
Medium
a. Dust
d. Soil
Paint
Location
b. Floor
c. Window Well
Type of Sample or
Method of Collection (Check)
_ Single Samples
H Composite Samples
D Single Samples
I] Composite Samples
D Single Samples
D Composite Samples
L~U Composite Samples
e. XRF
f. Paint Chips -Single Samples
g. Paint Chips - Composite Samples
No. of Samples
9 (n=1) (8-10)
• (n=0) (• - •)
• (n=0) (•-•)
• (n=0) (• - •)
• (n=0) (•-•)
n=0) (•-•)
2(n=1) (1-2)
10 (n=1) (10-10)
• (n=0) (•-•)
• (IPO) (-')
h. Other Optional Samples
Dust: For an average 3 bedroom home.
Paint: 3 samples per room being screened. No additional costs. Whatever necessary.
Soil: For an average 3 bedroom home.
C7. If more samples are required, do you have Yes
incremental costs for each additional sample? No
20% (n=5) {Go to C8}
80% (n=5) {Goto 01}
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 C-11
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-12-
C. LEAD HAZARD SCREEN (Continued)
C8. What are the incremental costs ?
Medium
Dust
Soil
Paint
Type of Sample
a. Single
b. Composite
c
d. XRF
e. Paint Chips - Single Samples
f. Paint Chips -Composite Samples
Collection
Cost Per
Sample
•(n=0)
(•-0
•(n=0)
(._.)
• (n=0)
(•-•)
• (n=0)
(._.)
• (n=0)
(...)
•(n=0)
(...)
Analysis Cost/
Sample
$10(n=1)
($10-$10)
• (n=0)
(...)
$12(n=1)
($12-$12)
• (n=0)
(...)
• (n=0)
(...)
• (n=0)
(._.)
Total Cost per
Environmental
Samples
$10(n=1)
($10-$10)
• (n=0)
._.)
$12(n=1)
($12-$12)
• (n=0)
(...)
•(n=0)
(...)
•(n=0)
._.)
g. Other Optional Samples
Paint: Free
(COMPLETED SECTION C — GO TO QUESTION D1)
Draft Report - Do Not Quote. Cite, Copy or Distribute
February 15, 1999 C-12
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-13-
C. LEAD HAZARD SCREEN (Continued)
C9. What are the additional fees for performing environmental sampling?
Medium
Dust
Soil
Paint
Type of Sample
a. Composite
b. Composite
c.XRF
d. Paint Chips - Single Samples
e. Paint Chips - Composite
No. of
Samples
• (n=0)
(._.)
• (n=0)
(._.)
• (n=0)
(._.)
• (n=0)
(._.)
• (n=0)
(•-•)
Collection
Cost Per
Sample
• (n=0)
(._.)
• (n=0)
(...)
• (n=0)
(...)
• (n=0)
(...)
•(n=0)
(•-•)
Analysis
Cost/
Sample
• (n=0)
(...)
• (n=0)
(...)
• (n=0)
(...)
• (n=0)
(...)
• (n=0)
(...)
Total Cost per
Environmental
Samples
•(n=0)
(...)
• (n=0)
(...)
• (n=0)
(...)
• (n=0)
(...)
• (n=0)
(...)
f. Other Optional Samples
(COMPLETED SECTION C — GO TO QUESTION D1)
SEPARATE FEE FOR EACH ACTIVITY
What is the overall cost for
C10. A Visual Assessment
C11. A Hazard Screen Report
C12. Typical Environmental Sampling
$175(n=2H$150-$200)
$200(n=2H$150-$250)
$200.25 fn=2)($175.50-$225)
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 C-13
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-14-
C. LEAD HAZARD SCREEN (Continued)
C13. What are the individual environmental sampling costs for
Medium
Dust
Soil
Paint
Type of Sample
a. Composite
b. Composite
c. XRF
d. Paint Chips - Single
Samples
e. Paint Chips - Composite
Samples
No. of
Samples
6(n=1)
(6-6)
2(n=1)
(2-2)
•(n=0)
(•-•)
5.75 (n=2)
(3-10)
•(n=0)
(•-•)
Collection
Cost Per
Sample
•(n=0)
(...)
• (n=0)
(._.)
•(n=0)
(•-•)
• (n=0)
(...)
• (n=0)
(._.)
Analysis Cost/
Sample
$20(n=1)
($20-$20)
$25(n=1)
($25-$25)
•(n=0)
(...)
$21.75(n=2)
(S18.50-S25)
-(n=0)
(•-•)
Total Cost per
Environmental
Samples
$120 (n=1)
($120-$ 120)
$50(n=1)
($50450)
•(n=0)
(...)
$1 22.63 (n=2)
($55.50-$185)
• (n=0)
(...)
f. Other Optional Samples
Dust
Single
4(n=2)
(2-6)
•(n=0)
(...)
$22.5 (n=2)
($20-$25)
$85 (n=2)
($50-$ 120)
Paint: Varies depending on home circumstance.
C14. If more environmental samples are
required do you have incremental costs
for each additional sample?
Yes ... 100%(n=2) .. {Goto015}
No .... 0%{n=2) ... (Goto01}
Draft Report - Do Not Quota, Cite, Copy or Distribute
February 15. 1999 C-14
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-15-
C. LEAD HAZARD SCREEN (Continued)
C15. What are the incremental costs?
Medium
Dust
Soil
Paint
Type of Sample
a. Composite
b. Composite
c. XRF
d. Paint Chips - Single Samples
e. Paint Chips - Composite Samples
Collection
Cost Per
Sample
• (n=0)
(...)
• (n=0)
(...)
• (n=0)
(...)
• (n=0)
(...)
•(n=0)
(...)
Analysis Cost/
Sample
$20 (n=1)
($20-$20)
$25 (n=1)
($25-$25)
• (n=0)
(•-•)
$21.75(n=2)
($18.50-$25)
• (n=0)
(...)
Total Cost per
Environmental
Samples
$20 (n=1)
(S20-S20)
$25(n=1)
($25-$25)
•(n=0)
(•-•)
$21.75(n=2)
($18.50-$25)
•(n=0)
(...)
f nthpr Optional Samples
Dust
Single
• (n=0)
(...)
$22.50 (n=2)
($20-$25)
$22.50 (n=2)
($20-$25)
(COMPLETED SECTION C — GO TO QUESTION D1)
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February 15. 1999 C-15
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-16-
D. INSPECTION
D1. Do you have a basic fee for performing an
inspection or does your fee depend on the
activities performed?
a. Basic Fee 67%(n=9)
{Go to question D2}
b. Separate Fees for each activity ... 33% (n=9)
{Go to question D10}
BASIC FEE INFORMATION
02. What is your basic fee for
an Inspection?
$300 (n=6) ($1254600)
D3. a. Is there a Visual Inspection included in the
Basic Fee?
Yes ....
No .....
100%(n=9)
0%(n=9)
{Go to 04}
b. What is the additional fee to
perform a Visual Inspection?
D4. a. Is a Risk Assessment Report included
in the Basic Fee?
Yes
No .
83% (n=6) {Goto D5}
17%(n=6)
b. What is the additional fee for the
Risk Assessment Report?
(n=0) (• -
D5. Is Environmental Sampling included
in the Basic Fee?
Yes
No
83% (n=6) {Goto D6}
17%(n=6) {CotoD9}
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February 15, 1999 C-16
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-17-
D. INSPECTION (Continued)
D6. How many and what type of environmental samples are collected for the basic fee (i.e., the average number
of samples collected)?
Medium
Paint
Dust
Soil
Water
Type of Sample or
Method of Collection (Check)
a. XRF
b. Paint Chips - Single Samples
c. Paint Chips - Composite Samples
Single
Composite
No. of Samples
117(n=2) (10-250)
•(n=0) (-•)
•(n=0) (•-•)
4.25 (n=2) (3-5)
1 (n=1) (1-1)
1 (n=1) (1-1)
d. Other Optional Samples
Dust: 3-4 where children play.
Paint: As many as needed.
As necessitated, usually 10.
For modest 3 bedroom, 200-250 reading.
If more samples are required, do you have Yes — i
incremental costs for each additional No (
10% (n=5) {G
>0%(n=5) {G
sample?
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February 15, 1999 C-17
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-18-
D. INSPECTION (Continued)
08. What are the incremental costs?
Medium
Paint
Surface-by-
Surface
Type of Sample
a. XRF
b. Paint Chips - Single Samples
c. Paint Chips - Composite Samples
d. Other Optional Samples
Dust
Soil
Water
Collection
Cost Per
Sample
• (n=0)
(...)
• (n=0)
(...)
•(n=0)
(...)
• (n=0)
(._.)
• (n=0)
(...)
• (n=0)
(._.)
Analysis
Cost/
Sample
• (n=0)
(...)
• (n=0)
(...)
•(n=0)
(...)
$10 (n=2)
($5-$15)
$15(n=1)
($15-$15)
$15(n=1)
($15-$15)
Total Cost Per
Environmental
Samples
•(n=0)
(...)
•(n=0)
(...)
•(n=0)
(...)
$10 (n=2)
($5-$15)
$15(n=1)
($15-$15)
$15(n=1)
($15-$15)
Dust: Only charge if more than 3-4 addition.
(COMPLETED SECTION D — GO TO QUESTION E1)
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February 15. 1999 C-18
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-19-
D. INSPECTION (Continued)
D9. What are the additional fees for performing environmental sampling?
Medium
Paint Surface-
by-Surface
Type of Sample
a. XRF
b. Paint Chips - Single Samples
No. of
Samples
65(n=1)
(65-65)
•(n=0)
(...)
Collection
Cost Per
Sample
•(n=0)
• (n=0)
(...)
Analysis
Cost/
Sample
•(n=0)
(...)
•(n=0)
(...)
Total Cost per
Environmental
Samples
• (n=0)
(...)
• (n=0)
(...)
c. Other Optional Samples
(COMPLETED SECTION D — GO TO QUESTION E1)
SEPARATE FEE FOR EACH ACTIVITY
What is the overall cost of
D10. A Visual Assessment
D11. An Inspection Report
D12. Typical Environmental Sampling
$490 (n=3) ($200-8750)
$380 (n=2) ($260-3500)
$348.67 (n=3) ($18.50-$750)
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February 15, 1999 C-19
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-20-
D. INSPECTION (Continued)
D13. What are the individual environmental sampling costs for
Medium
Paint
Surface-by-
Surface
Type of Sample
a. XRF
b. Paint Chips - Single
Samples
No. of
Samples
• (n=0)
35.83 (n=3)
(15-50)
Collection
Cost Per
Sample
• (n=0)
• (n=0)
(...)
Analysis Cost/
Sample
• (n=0)
(...)
$20.67 (n=3)
($18.50-$25)
c. Other Optional Samples
Paint Surface-bv-Surface: Varies depending on home circumstances.
Total Cost per
Environmental
Samples
• (n=0)
(...)
$727.92 (n=3)
($277.50-$925)
D14. If more environmental samples are
required do you have incremental costs
for each additional sample?
Yes
No
100%(n=3)
0% (n=3)
{Go to D15}
. {GotoEl}
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February 15, 1999 C-20
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-21-
D. INSPECTION (Continued)
D15. What are the incremental costs?
Medium
Type of Sample
Analysis Cost/
Sample
Total Cost per
Environmental
Samples
a.XRF
• (n=0)
• (n=0)
Paint Surface-by-
Surface
b. Paint Chips - Single Samples
$20.67 (n=3)
($18.50-325)
$20.67 (n=3)
($18.50-$25)
c. Other Optional Samples
(COMPLETED SECTION D — GO TO QUESTION E1)
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February 15, 1999 C-21
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-22-
E. RISK ASSESSMENT/INSPECTION
E1. Is the cost of performing a combination risk
assessment/inspection different from the
cost of the risk assessment plus the cost of
the inspection?
Yes 89% (n=9)
No {Conclude Interview-
Go to Last Page} 11%(n=9)
E2. Do you have a basic fee for performing a
combination risk assessment/inspection?
Does your fee depend on the activities
performed?
a. Basic Fee 62% (n=8)
{Go to question E3}
b. Separate Fees for each activity — 38% (n=8)
{Go to question £11}
BASIC FEE INFORMATION
E3. What is your basic fee for a Risk
Assessment/Inspection?
$886.25 (n=4) ($190-$ 1905)
E4. a. Is there a Visual Inspection included in the
Basic Fee?
Yes .... 100% (n=5) .... {Go to £5}
No 0%(n=5)
b. What is the additional fee to
perform a Visual Inspection?
(n=0) (• - •)
E5. a. Is a Risk Assessment Report
included in the Basic Fee?
Yes .... 100%(n=5) .... {GotoE6}
No 0% (n=5)
b. What is the additional fee for the
Risk Assessment Report?
(n=0) (• - •)
E6. Is Environmental Sampling
included in the Basic Fee?
Yes 80%(n=5) {GotoE?}
No 20%(n=5) {Go to £10}
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February 15, 1999 C-22
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-23-
E. RISK ASSESSMENT/INSPECTION (Continued)
E7. How many and what type of environmental samples are collected for the basic fee (i.e., the average number
of samples collected)?
Medium
a. Soil
b. Dust
Paint
Location
c. Floor
d. Window Sill
e. Window Well
Type of Sample or
Method of Collection (Check)
Q Composite
D Single Samples
I] Composite Samples
D Single Samples
H Composite Samples
H Single Samples
H Composite Samples
H Single Samples
I] Composite Samples
f. XRF
g. Paint Chips - Single Samples
h. Paint Chips - Composite Samples
No. of Samples
3 (n=3) (1-5)
• (n=0) (•-•)
10 (n=1) (10-10)
2 (n=1) (2-2)
• (n=0) (•-•)
• (n=0) (•-•)
• (n=0) (•-•)
• (n=0) (•-•)
• (n=0) (•-•)
• (n=0) {•-•)
• (n=0) (•-•)
15 (n=2) (1-30)
• (n=0) (•-•)
i. Other Optional Samples
Dust
Water
6 (n=2) (5-8)
1 (n=1) (1-1)
Paint: As many as necessary. If paint is peeling.
Soil: If needed.
Water: If needed.
E8. If more samples are required, do you have
incremental costs for each additional
sample?
Yes 100% (n=4)
No ... {Conclude Interview -
Go to Last Page} 0% (n=4)
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February 15, 1999 C-23
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-24-
E. RISK ASSESSMENT/INSPECTION (Continued)
E9. What are the incremental costs ?
Medium
Dust
Soil
Paint Surface-by-
Surface
Type of Sample
a. Single Sample
b. Composite Sample
c. Composite
d. XRF
e. Paint Chip (1 sample from
each component in a room)
Collection
Cost Per
Sample
•(n=0)
(•-•)
•(n=0)
(...)
•(n=0)
(•-•)
•(n=0)
(•-•)
• (n=0)
(._.)
Analysis Cost/
Sample
$13.75 (n=4)
($5-$25)
• (n=0)
(•-•)
$13.75(n=4)
($5-$25)
•(n=0)
(._.)
$15 (n=2)
($5-$25)
Total Cost per
Environmental
Samples
$13.75 (n=4)
($5-$25)
• (n=0)
(...)
$13.75 (n=4)
($5-$25)
• (n=0)
(...)
$15(n=2)
($5-$25)
f. Other Optional Samples
Water
Paint Surface-by-Surface: Additional samples are free.
• (n=0)
(...)
$10 (n=3)
($5-$15)
$10(n=3)
($5-$15)
(COMPLETED SECTION E — CONCLUDE INTERVIEW — GO TO LAST PAGE)
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February 15, 1999 C-24
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-25-
E. RISK ASSESSMENT/INSPECTION (Continued)
E10. What are the additional fees for performing environmental sampling?
Medium
Dust
Soil
Paint Surface-by-
Surface
Type of Sample
a. Single Sample
b. Composite Sample
c. Composite
d. XRF
e. Paint Chip (1 sample
from each component
in a room)
No. of
Samples
5(n=1)
(5-5)
• (n=0)
(._.)
1 (n=1)
(1-1)
• (n=0)
(...)
• (n=0)
(•-•)
Collection
Cost Per
Sample
• (n=0)
(...)
• (n=0)
(._.)
•(n=0)
(...)
• (n=0)
(...)
• (n=0)
(...)
Analysis
Cost/
Sample
$15(n=1)
($15-$15)
• (n=0)
(...)
$15(n=1)
($15-$15)
• (n=0)
(...)
• (n=0)
(...)
Total Cost per
Environmental
Samples
$75(n=1)
($75-$75)
• (n=0)
(...)
$15(n=1)
($15-$15)
• (n=0)
(...)
• (n=0)
(...)
f. Other Optional Samples
Water
Single
Paint Surface-by-Surface: No additional fee.
1 (n=1)
(1-D
• (n=0)
(...)
$15(n=1)
($15-$15)
$15(n=1)
(S15-S15)
(COMPLETED SECTION E — CONCLUDE INTERVIEW — GO TO LAST PAGE)
SEPARATE FEE FOR EACH ACTIVITY
What is the overall cost of
E11. A Visual Assessment
$650(n=3)($200-$1500)
E12. A Risk Assessment/
Inspection Report
E13. Typical Environmental Sampling
$312.50 (n=2)($125-$500)
S694.17(n=3)($140-$1325)
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February 15, 1999 C-25
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-26-
E. RISK ASSESSMENT/INSPECTION (Continued)
E14. What are the individual environmental sampling costs for
Medium
Dust
Soil
Paint Rurface-
by-Surface
Type of Sample
a. Single Sample
b. Composite Sample
c. Composite
d. XRF
e. Paint Chip (1 sample
from each component
in a room)
No. of
Samples
12.33 (n=3)
(7-25)
•(n=0)
10(n=1)
(10-10)
10(n=1)
(10-10)
38.75 (n=2)
(15-50)
Collection
Cost Per
Sample
• (n=0)
• (n=0)
• (n=0)
(...)
• (n=0)
(...)
• (n=0)
Analysis Cost/
Sample
$22.5 (n=3)
($20-$30)
•(n=0)
$20(n=1)
($20-$20)
•(n=0)
(•-•)
$18.30(n=2)
($16.5-$20)
Total Cost per
Environmental
Samples
$302.92 (n=3)
($140-$750)
• (n=0)
(•-•)
$200 (n=1)
($200-$200)
•(n=0)
(...)
$710.63 (n=2)
($277.50-$1000)
f. Other Optional Samples
Dust: Varies depending on home circumstance.
Paint: Varies depending on home circumstance.
E15. If more environmental samples are
required do you have incremental costs for
each additional sample?
Yes 100% (n=3)
No .. 0% (n=3) {Conclude
Interview - Go to Last Page)
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February 15, 1999 C-26
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-27-
E. RISK ASSESSMENT/INSPECTION (Continued)
E16. What are the incremental costs?
Medium
Dust
Soil
Paint Surface-by-
Surface
Type of Sample
a. Single Sample
b. Composite Sample
c. Composite
d.XRF
e. Paint Chip (1 sample
from each component
in a room)
Collection
Cost Per
Sample
• (n=0)
(•-•)
• (n=0)
(._.)
• (n=0)
(._.)
•(n=0)
(...)
•(n=0)
(•-•)
Analysis Cost/
Sample
$22.50 (n=3)
($20-$30)
• (n=0)
(...)
• (n=0)
(...)
• (n=0)
(...)
$18.38(n=2)
($16.50420)
Total Cost per
Environmental
Samples
$22.50 (n=3)
($20-$30)
•(n=0)
(...)
•(n=0)
(•-•)
•(n=0)
(...)
$18.38(n=2)
($16.50420)
f. Other Optional Samples
(COMPLETED SECTION E — CONCLUDE INTERVIEW)
CONCLUSION TO INTERVIEW
I would like to thank you for participating in this evaluation. Let me just double check your address so we can send the
results when they are available. {Go to first page.}
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February 15, 1999 C-27
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APPENDIX D
Choices for a Risk Assessor
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APPENDIX D
Choices for a Risk Assessor
As described in section 402 and summarized in Appendix A, by design a risk assessor is
given the freedom to make sampling choices while performing a risk assessment. Listed below
are the areas in which a risk assessor may make a choice.
1. Types of samples taken or techniques used to collect the samples
Dust Composite or single samples
Soil Core or surface scrapings
Paint XRF or bulk (paint scrapings)
2. Sampling locations
Dust Composite samples Child's principal play area, kitchen, bedroom of
youngest child between 6 months and 6 years of
age, and bedroom of next oldest child
Single samples Entry way (including porches), child's principal
play area, children's bedrooms, kitchen, bathroom,
other rooms
3. Sampling components
Dust Composite samples Uncarpeted floors (carpeted if no uncarpeted floors
available), interior window sills, window troughs
Single samples Uncarpeted floors (carpeted if no uncarpeted floors
available), interior window sills, window troughs
4. Number of samples
Dust Composite samples 3 or more composite samples; 2 to 4 single samples
per composite
Single samples 6 or more single samples
Soil 1 or 2 composite samples
5. Performing a Lead Hazard Screen.
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APPENDIX E
Blood and Environmental
Sampling Standards
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APPENDIX E
Blood and Environmental
Sampling Standards
The environmental levels (media standards) used to determine if a home passes or fails a
risk assessment are based upon EPA's Section 403 Interim Guidance and Section 403 Proposed
Rule on identification of lead-based paint hazards. The blood-lead concentration target levels are
based on EPA's Section 403 Interim Guidance and CDC's recommendations. Listed below are
the standards used in the analysis.
Blood Section 402 describes an elevated blood-lead level (EBL) as an excessive
absorption of lead that is a confirmed concentration of lead in whole blood of
20 ug/dL for a single venous test or 15 to 19 ug/dL in two consecutive
samples taken 3 to 4 months apart. The CDC elevated blood lead level is
defined as 10 ug/dL or greater.
Dust The risk assessment standards for uncarpeted floors (or carpeted floors if
uncarpeted floors are not available), window sills, and windows troughs are
Floors * 100 ug/ft2
Window sills * 500 ug/ft2
Window troughs * 800 ug/ft2
for Section 403 Interim Guidance, and
Floors * 50 ug/ft2
Window sills * 250 ug/ft2
for Section 403 Proposed Rule.
No window trough standard was specified in Section 403 Proposed Rule.
The lead hazard screen standards for uncarpeted floors (or carpeted floors if
uncarpeted floors are not available), and window trough samples are
Floors * 50 ug/ft2
Window sills * 250 ug/ft2
Window troughs :> 400 ug/ft2
for Section 403 Interim Guidance, and
Draft Report - Do Not Quote, Cite, Copy or Distribute February 15. 1999 E-2
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Floors * 25 ug/ft2
Window sills * 125 jig/ft2
for Section 403 Proposed Rule.
Soil The risk assessment standard for soil is * 5000 ppm for Section 403 Interim
Guidance, and 2 2000 ppm for Section 403 Proposed Rule
Note: This is the lowest level at which any intervention is recommended.
Paint Section 402 defines lead-based paint as paint or other surface coatings that
contain lead equal to or in excess of 1.0 mg/cm2 or more than 0.5% by weight.
Under the Section 403 Interim Guidance, any surface with deteriorated paint
must be tested to see if there is lead-based paint. The Section 403 Proposed
Rule requires that areas where 1) 2> 2 ft2 deteriorated for large interior
components; 2) * 10 ft2 deteriorated for large exterior components; and 3) *
10% of the surface deteriorated for small components must be tested for lead-
based paint.
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APPENDIX F
Data Set Criteria
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APPENDIX F
Data Set Criteria
The following are criteria to be used to evaluate the usefulness of available data sets in
the assessment of section 402 risk assessment protocols. Optimally a data set will meet all the
criteria. However, some analyses may not require all media. Therefore a data set may be
accepted for analysis based on a subset of the criteria listed below.
General Information
1. Report the date of blood sampling.
2. Report the date of environmental sampling.
3. Report the length of time the child has lived in the home (3 or more months).
Blood
1. Pre-intervention blood-lead concentration for at least one child in a home with the
child's age being between 6 months and 6 years.
2. Report the blood sampling technique (venous puncture or finger stick)
Dust
1. Report the lead loadings for the dust samples.
2. All samples taken at the time of or following the blood sampling but prior to any
intervention activities.
3. More than two sampling locations (children's primary play area, kitchen, bedroom,
etc.)
4. Sampling components must include uncarpeted floors (carpeted floors if no
uncarpeted floors available) or window sills.
Draft Report - Do Not Quote, Cite, Copy or Distribute February 15, 1999 F-2
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5. Six or more single samples from components in at least two locations OR Multiple
composite samples (at least two composite samples from uncarpeted floors or two
from window sills. If uncarpeted floors cannot be sampled then at least two
composite samples from carpeted floors).
6. Sampling technique must be wipe.
7. Report the lab analysis technique for the wipes
8. Report the LOD for the samples.
Soil
1. Report the lead levels for the soil samples.
2. All samples taken at the time of or following the blood sampling but prior to any
intervention activities.
3. At least one composite sample from the child's principal play area and a second
composite sample from the buildings foundation. (Note: if it is reported that there is
no bare soil then a soil sample will not be required).
4. Report the soil sampling technique (core or surface scraping).
5. Report ground covering information (Types of information include: bare, ground
cover, % covered, etc.). Note: This is not a make or break requirement. This is the
type of information a risk assessor will be collecting. If the information is not
reported then an assumption might be made that the soil samples were taken from
bare areas.
6. Report the lab analysis techniques for the composite soil samples.
7. Report the LOD for the samples.
Paint
1. Report the lead levels of the paint samples.
2. All samples taken prior to any interventions.
3. Report the sampling locations (interior or exterior first and then bedroom, living
room, side of house, etc).
Draft Report - Do Not Quote. Cite, Copy or Distribute February 15. 1999 F-3
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4. Report the components sampled (walls, window sills, window troughs, etc) and be
able to associate with a sampling location.
5. Report the sampling technique (XRF or bulk (paint scrapings)). If paint chip
sampling is used, report whether a composite sample or a single sample.
6. Report the condition of the paint (poor, % deteriorated or ft2 deteriorated, etc.).
Draft Report - Do Not Quote. Cite, Copy or Distribute February 15, 1999 F-4
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APPENDIX G
Summary Tables and Figures
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Table G-1. Average Cost Per Sample and Average Number of Samples Collected for
Sampling Performed by a Certified Risk Assessor During a Risk Assessment.
Lead Hazard Screen. Inspection, and Risk Assessment/Inspection for Agency
NE-1.
=^=^=
Media
Dust
Paint
Soil
Water
^=^=^=
Type of Sample
Single
Paint Chips -
Composite
Paint Chips - Single
XRF
Composite
Single
^=^=^=^=^=^=
Cost Per Sample ($)
Minimum Cost - Maximum Cost
Collection Cost
(a)
(a)
la)
(a)
(a)
(a)
(a)
(a)
=^=^=^=^=
Analysis Cost
(a)
$15.00
$15.00- $15.00
(a)
(a)
(a)
$15.00
$15.00- $15.00
(a)
$15.00
$15.00- $15.00
«^^g^^^^^^^=
Total Cost
(a)
$15.00
$15.00- $15.00
(a)
(a)
(a)
$15.00
$15.00- $15.00
(a)
$15.00
$15.00- $15.00
^^^^=5^^^=
Number of
Samples
Collected
=^=^=^=
(b)
4.3
3-5
(b)
(b)
(b)
1
1 - 1
(b)
1
1 -1
i:^==^=!J
No cost was reported.
The number of samples collected was not reported.
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February 15, 1999 G-2
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Table G-2. Average Cost Per Sample and Average Number of Samples for Sampling
Performed by a Certified Risk Assessor During a Risk Assessment, Lead
Hazard Screen, Inspection, Risk Assessment/Inspection for Agency NE-2.
Media
Dust
Paint
Soil
Water
Type of Sample
Composite
Single
Paint Chips -
Composite
Paint Chips - Single
XRF
Composite
Single
Cost Per Sample {$)
Minimum Cost - Maximum Cost
Collection Cost
(a)
(a)
(a)
(a)
(a)
(a)
(a)
(a)
Analysis Cost
(a)
$10.00
$10.00 -$10.00
(a)
(a)
(a)
$10.67
$10.00- $12.00
(a)
$10.00
$10.00- $10.00
Total Cost
(a)
$10.00
$10.00- $10.00
(a)
la)
la)
$10.67
$10.00- $12.00
(a)
$10.00
$10.00- $10.00
Number of
Samples
Collected
(b)
7.7
6-10
(b)
(b)
225
200 - 250
1.5
1 -2
(b)
(b)
8 No cost was reported.
b The number of samples collected was not reported.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 G-3
-------
Table G-3. Average Cost Per Sample and Average Number of Samples for Sampling
Performed by a Certified Risk Assessor During a Risk Assessment, Lead
Hazard Screen, Inspection, Risk Assessment/Inspection for Agency NE-3.
Media
Dust
Paint
Soil
Water
Type of Sample
Composite
Single
Paint Chips -
Composite
Paint Chips - Single
XRF
Composite
Single
Cost Per Sample ($)
Minimum Cost - Maximum Cost
Collection Cost
$10.00
$10.00 -$10.00
$10.00
$10.00 -$10.00
(a)
(a)
(a)
$15.00
$15.00 -$15.00
(a)
$15.00
$15.00- $15.00
Analysis Cost
$15.00
$15.00- $15.00
$15.00
$15.00- $15.00
(a)
(a)
(a)
$10.00
$10.00- $10.00
(a)
$10.00
$10.00- $10.00
Total Cost
$25.00
$25.00 - $25.00
$25.00
$25.00 - $25.00
(a)
(a)
(a)
$25.00
$25.00 - $25.00
(a)
$25.00
$25.00 - $25.00
Number of
Samples
Collected
5.5
3-8
5.5
3-8
(b)
(b)
65
65-65
3
2-4
(b)
(b)
8 No cost was reported.
b The number of samples collected was not reported.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 G-4
-------
Table G-4. Average Cost Per Sample and Average Number of Samples for Sampling
Performed by a Certified Risk Assessor During a Risk Assessment, Lead
Hazard Screen, Inspection, Risk Assessment/Inspection for Agency NE-4.
—
Media
==:
Dust
Paint
Soil
Water
======
Type of Sample
Composite
Single
Paint Chips -
Composite
Paint Chips - Single
XRF
Composite
Single
Cost Per Sample ($)
Minimum Cost - Maximum Cost
Collection Cost
=====
(a)
(a)
(a)
(a)
(a)
(a)
(a)
(a)
Analysis Cost
=====
(a)
$20.00
$20.00 - $20.00
(a)
(a)
(a)
(a)
(a)
(a)
Total Cost
(a)
$20.00
$20.00 - $20.00
(a)
(a)
(a)
(a)
(a)
(a)
Number of
Samples
Collected
(b)
7
7-7
(b)
10
10- 10
Ib)
(b)
(b)
(b)
a No cost was reported.
b The number of samples collected was not reported.
Draft Report - Do Not Quote. Cite, Copy or Distribute
February 15. 1999 G-5
-------
Table G-5. Average Cost Per Sample and Average Number of Samples for Sampling
Performed by a Certified Risk Assessor During a Risk Assessment, Lead
Hazard Screen, Inspection, Risk Assessment/Inspection for Agency S-1.
Media
Dust
Paint
Soil
Water
Type of Sample
Composite
Single
Paint Chips -
Composite
Paint Chips - Single
XRF
Composite
Single
Cost Per Sample ($)
Minimum Cost - Maximum Cost
Collection Cost
(a)
(a)
(a)
(a)
(a)
(a)
(a)
(a)
Analysis Cost
la)
$27.50
$25.00 - $30.00
(a)
(a)
(a)
(a)
(a)
(a)
Total Cost
(a)
$27.50
$25.00 - $30.00
(a)
(a)
(a)
(a)
(a)
(a)
Number of
Samples
Collected
(b)
22.5
20-25
(b)
(b)
(b)
(b)
(b)
(b)
3 No cost was reported.
b The number of samples collected was not reported.
Draft Report - Do Not Quote. Cite. Copy or Distribute
February 15. 1999 G-6
-------
Table G-6. Average Cost Per Sample and Average Number of Samples for Sampling
Performed by a Certified Risk Assessor During a Risk Assessment, Lead
Hazard Screen, Inspection, Risk Assessment/Inspection for Agency S-2.
Media
Dust
Paint
Soil
Water
Type of Sample
Composite
Single
Paint Chips -
Composite
Paint Chips - Single
XRF
Composite
Single
Cost Per Sample {$)
Minimum Cost - Maximum Cost
Collection Cost
(a)
(a)
(a)
(a)
(a)
(a)
(a)
(a)
Analysis Cost
(a)
$25.00
$25.00 - $25.00
(a)
(a)
(a)
$25.00
$25.00 - $25.00
(a)
(a)
Total Cost
(a)
$25.00
$25.00 - $25.00
(a)
(a)
(a)
$25.00
$25.00 - $25.00
(a)
(a)
Number of
Samples
Collected
(b)
7.3
2- 10
(b)
(b)
(b)
4
2-5
(b)
(b)
8 No cost was reported.
b The number of samples collected was not reported.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 G-7
-------
Table G-7. Average Cost Per Sample and Average Number of Samples for Sampling
Performed by a Certified Risk Assessor During a Risk Assessment, Lead
Hazard Screen, Inspection, Risk Assessment/Inspection for Agency S-3.
Media
Dust
Paint
Soil
Water
Type of Sample
Composite
Single
Paint Chips -
Composite
Paint Chips - Single
XRF
Composite
Single
Cost Per Sample ($)
Minimum Cost - Maximum Cost
Collection Cost
(a)
(a)
(a)
(a)
(a)
(a)
(a)
(a)
Analysis Cost
$20.00
$20.00 - $20.00
$20.00
$20.00 - $20.00
(a)
(a)
(a)
$20.00
$20.00 - $20.00
(a)
(a)
Total Cost
$20.00
$20.00 - $20.00
$20.00
$20.00 - $20.00
(a)
(a)
(a)
$20.00
$20.00 - $20.00
(a)
(a)
Number of
Samples
Collected
6
6-6
7
6-8
(b)
(b)
(b)
10
10- 10
(b)
(b)
a No cost was reported.
b The number of samples collected was not reported.
Draft Report - Do Not Quote, Cite. Copy or Distribute
February 15, 1999 G-8
-------
Table G-8. Average Cost Per Sample and Average Number of Samples for Sampling
Performed by a Certified Risk Assessor During a Risk Assessment, Lead
Hazard Screen, Inspection, Risk Assessment/Inspection for Agency W-1.
Media
Dust
Paint
Soil
Water
Type of Sample
Composite
Single
Paint Chips -
Composite
Paint Chips - Single
XRF
Composite
Single
Cost Per Sample ($)
Minimum Cost - Maximum Cost
Collection Cost
(a)
(a)
(a)
(a)
(a)
(a)
(a)
(a)
Analysis Cost
(a)
$5.00
$ 5.00 - $ 5.00
(a)
(a)
(a)
$ 5.00
$ 5.00 - $ 5.00
(a)
$5.00
$ 5.00 - $ 5.00
Total Cost
(a)
$5.00
$ 5.00 - $ 5.00
(a)
(a)
(a)
$ 5.00
$ 5.00 - $ 5.00
(a)
$5.00
$ 5.00 - $ 5.00
Number of
Samples
Collected
(b)
4.5
3-5
(b)
(b)
(b)
3
3-3
(b)
(b)
8 No cost was reported.
b The number of samples collected was not reported.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 G-9
-------
Table G-9. Average Cost Per Sample and Average Number of Samples for Sampling
Performed by a Certified Risk Assessor During a Risk Assessment, Lead
Hazard Screen, Inspection, Risk Assessment/Inspection for Agency W-2.
Media
Dust
Paint
Soil
Water
Type of Sample
Composite
Single
Paint Chips -
Composite
Paint Chips - Single
XRF
Composite
Single
Cost Per Sample ($)
Minimum Cost - Maximum Cost
Collection Cost
(a)
(a)
(a)
(a)
(a)
(a)
(a)
(a)
Analysis Cost
$15.00
$15.00 -$15.00
$15.00
$15.00 -$15.00
(a)
la)
la)
$15.00
$15.00 -$15.00
(a)
$15.00
$15.00 -$15.00
Total Cost
$15.00
$15.00 -$15.00
$15.00
$15.00 -$15.00
(a)
(a)
(a)
$15.00
$15.00 -$15.00
(a)
$15.00
$15.00- $15.00
Number of
Samples
Collected
2
2-2
(b)
(b)
(b)
(b)
1
1 - 1
(b)
1
1 - 1
8 No cost was reported.
b The number of samples collected was not reported.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 G-10
-------
Table G-10. Sampling Protocol A: Assessment of the Impact of the Number of Rooms in
Which Dust Wipe Samples are Collected on the Outcome of a Full Risk
Assessment, Using the Interim Guidance Standards (XRF Paint Samples from
Surfaces With > 15% Deteriorated Paint).
# Homes included in analysis
Number of individual samples per home
% of Homes Failing the Risk Assessment
(# Homes Failing / # Homes)
% of Blood Samples 2 10//g/dL
Sampling Protocol Group A
A-1
(4 Rooms)
83
8-9
84.3%
A-2
(3 Rooms)
83
7
83.1%
A-3
(2 Rooms)
83
6
83.1%
20.5%
% of Homes Failing the Risk Assessment on Media Standards
(# of Homes Failing/if Homes in which samples were collected)
All Floors
Carpeted Floors Only
Uncarpeted Floors Only
Window Sill
Window Well
Soil
Dripline Soil Only
Play Area Soil Only
Paint (> 15% deteriorated)
9.6% (8/83)
3.9% (3/76)
7.3% (6/82)
21. 7% (18/83)
8 1.9% (68/83)
7.8% (6/77)
7.8% (6/77)
0% (0/40)
90.3% (28/31)
7.2% (6/83)
3.9% (3/76)
6.9% (4/58)
2 1.7% (18/83)
80.7% (67/83)
7.8% (6/77)
7.8% (6/77)
0% (0/40)
90.3% (28/31)
2.4%(2/83)
1.3% (1/75)
3.4% (1/29)
2 1.7% (18/831
80.7% (67/83)
7.8% (6/77)
7.8% (6/77)
0% (0/40)
90.3% (28/31)
Performance Characteristics
Sensitivity
(LCB, UCB)
Specificity
(LCB, UCB)
Positive Predictive Value
(LCB, UCB)
Negative Predictive Value
(LCB. UCB)
88.2%
(63.6%. 98.5%)
16.7%
(8.6%, 27.9%)
21.4%
(12.5%, 32.9%)
84.6%
(54.6%.98.1%)
88.2%
(63.6%. 98.5%)
18.2%
(9.8%, 29.6%)
21.7%
(12.7%, 33.3%)
85.7%
(57.2%. 98.2%)
88.2%
(63.6%. 98.5%)
18.2%
(9.8%. 29.6%)
21.7%
(12.7%, 33.3%)
85.7%
(57.2%. 98.2%)
Note: 1. Floor, window sill, and window well samples were collected as dust wipes, soil was collected as
a core sample, and XRF measurements were taken for paint.
2. See Table 5-3 for definitions of sampling protocols A-1, A-2, and A-3.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 G-11
-------
Table G-11. Sampling Protocol A: Assessment of the Impact of the Number of Rooms in
Which Dust Wipe Samples are Collected on the Outcome of a Full Risk
Assessment, Using the Proposed Rule Standards (XRF Paint Samples from
Surfaces With >15% Deteriorated Paint).
# Homes included in analysis
Number of individual samples per home
% of Homes Failing the Risk Assessment
(# Homes Failing / # Homes)
% of Blood Samples 2 lOi/g/dL
Sampling Protocol Group A
A-1
(4 Rooms)
83
8-9
60.2%
A-2
(3 Rooms)
83
7
59.0%
A-3
(2 Rooms)
83
6
57.8%
20.5%
% of Homes Failing the Risk Assessment on Media Standards
(# of Homes Failing/0 Homes in which samples were collected)
All Floors
Carpeted Floors Only
Uncarpeted Floors Only
Window Sill
Window Well
Soil (Average of average
dripline and average play
area)
Dripline Soil Only
Play Area Soil Only
Paint (> 15% deteriorated)
10.8% (9/83)
2.6% (2/76)
9.8% (8/82)
28.9% (24/83)
9.6% (8/83)
2.6% (2/76)
12.1% (7/58)
28.9% (24/83)
NA
27.3% (21/77)
27.3% (21/77)
4.8% (4/83)
1.3% (1/75)
10.3% (3/29)
28.9% (24/83)
27.3% (21/77)
NA
NA
90.3% (28/31)
90.3% (28/31)
90.3% (28/31)
Performance Characteristics
Sensitivity
(LCB, UCB)
Specificity
(LCB, UCB)
Positive Predictive Value
(LCB, UCB)
Negative Predictive Value
(LCB UCB)
82.4%
(56.6%, 96.2%)
45.5%
(33.1%, 58.2%)
28.0%
(16.2%, 42.5%)
90.9%
(75 7% 98 1%)
76.5%
(50.1%, 93.2%)
45.5%
(33.1%, 58.2%)
26.5%
(14.9%, 41.1%)
88.2%
(72.5%. 96.7%)
76.5%
(50.1%, 93.2%)
47.0%
(34.6%. 59.7%)
27.1%
(15.3%. 41.8%)
88.6%
(73.3%. 96.8%)
Note:1. Floor and window sill samples were collected as dust wipes, soil was collected as a core, and XRF
measurements were taken for paint. Window well samples are not required under the Proposed
Rule.
2. See Table 5-3 for definitions of sampling protocols A-1, A-2, and A-3.
3 NA indicates that these samples were not included in the analysis.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 G-12
-------
Table G-12. Sampling Protocol A: Assessment of the Impact of the Number of Rooms in
Which Dust Wipe Samples are Collected, Using the Interim Guidance
Standards (No Soil or Paint Sampling).
1=======
=======
# Homes included in analysis
Number of individual samples / homes
% of Homes Failing the Risk Assessment
(# Homes Failing / # Homes)
% of Blood Samples * 10 j/g/dL
Sampling Protocol Group A
A-1
(4 Rooms)
==^===
83
8-9
81.9%
A-2
(3 Rooms)
=^=^=^=
83
7
80.7%
A-3
(2 Rooms)
83
6
80.7%
20.5%
% of Homes Failing the Risk Assessment on Media Standards
(# of Homes Failing/i!i Homes in which samples were collected)
Uncarpeted Floors Only
Window Sill
Window Well
Soil
Play Area Soil Only
9.6% (8/83)
3.9% (3/76)
7.3% (6/82)
21. 7% (18/83)
81. 9% (68/83)
7.2% (6/83)
3.9% (3/76)
6.9% (4/58)
21. 7% (18/83)
80.7% (67/83)
2.4% (2/83)
1.3% (1/75)
3.4% (1/29)
21. 7% (18/83)
80.7% (67/83)
NA
NA
NA
NA
Sensitivity
(LCB, UCB)
Specificity
(LCB. UCB)
Positive Predictive Value
ILCB, UCB)
Negative Predictive Value
(LCB. UCB)
88.2%
(63.6%, 98.5%)
19.7%
(10.9%. 31.3%)
22.1%
(12.9%, 33.8%)
86.7%
(59.5%, 98.3%)
==^^^=^^^^^^^^=
88.2%
(63.6%, 98.5%)
21.2%
(12.1%, 33.0%)
22.4%
(13.1%. 34.2%)
87.5%
(61.7%. 98.4%)
=^^^^^^^^=^^^^^
88.2%
(63.6%, 98.5%)
21.2%
(12.1%, 33.0%)
22.4%
(13.1%. 34.2%)
87.5%
(61.7%, 98.4%)
^^^^^====^=^=1
Note: 1. Floor, window sill, and window well samples were collected as dust wipes.
2. See Table 5-3 for definitions of sampling protocols A-1, A-2, and A-3.
3 NA indicates that these samples were not included in the analysis.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 G-13
-------
Table G-13. Sampling Protocol A: Assessment of the Impact of the Number of Rooms in
Which Dust Wipe Samples are Collected. Using the Proposed Rule Standards
(No Soil or Paint Sampling).
======
% of Homes Failing the Risk Assessment
iff Homes Failing / # Homes)
Sampling Protocol Group A
A-1
(4 Rooms)
^=^=^=^=^=
83
8-9
33.7%
A-2
(3 Rooms)
83
7
32.5%
A-3
(2 Rooms)
83
6
30.1%
20.5
% of Homes Failing the Risk Assessment on Media Standards
iff of Homes Failing/* Homes in which samples were collected)
Carpeted Floors Only
Uncarpeted Floors Only
Window Sill
Soil (Average of average dripline
Dripline Soil Only
Play Area Soil Only
10.8% (9/83)
2.6% (2/76)
9.8% (8/82)
28.9 (24/83)
9.6% (8/83)
2.6% (2/76)
12.1% (7/58)
28.9% (24/83)
4.8% (4/83)
1.3% (1/75)
10.3% (3/29)
28.9% (24/83)
NA
NA
NA
NA
NA
Sensitivity
(LCB, UCB)
Specificity
(LCB. UCB)
Positive Predictive Value
(LCB, UCB)
Negative Predictive Value
(LCB. UCB)
64.7%
(38.3%, 85.8%)
74.2%
(62.0%, 84.2%)
39.3%
(21.5%, 59.4%)
89.1%
(77.8%. 95.9%)
58.8%
(32.9%, 81.6%)
74.2%
(62.0%, 84.2%)
37.0%
(19.4%, 57.6%)
87.5%
(75.9%. 94.8%1
58.8%
(32.9%, 81.6%)
77.3%
(65.3%, 86.7%)
40.0%
(21.1%. 61.3%)
87.9%
(76.7%. 95.0%)
Note: 1. Floor, window sill, and window well samples were collected as dust wipes.
2. See Table 5-3 for definitions of sampling protocols A-1, A-2, and A-3.
3 NA indicates that these samples were not included in the analysis.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 G-14
-------
Table G-14. Sampling Protocol B: Comparison of Various Methods of Characterizing Dust
Wipe Samples Obtained in a Full Risk Assessment, Using the Interim
Guidance Standards (XRF Paint Samples from Surfaces With > 15%
Deteriorated Paint).
# Homes included in analysis
% of Homes Failing the Risk Assessment
(# Homes Failing / # Homes)
Sampling Protocol Group B
B-1
(Geometric Mean)
112
70.5%
B-2
(Arithmetic Mean)
112
78.6%
B-3
(Maximum Value)
112
84.8%
21.4%
% of Homes Failing the Risk Assessment on Media Standards
(ft of Homes Failing/* Homes in which samples were collected)
All Floors
Carpeted Floors Only
Uncarpeted Floors Only
Window Sill
Window Well
Soil
Dripline Soil Only
Play Area Soil Only
Paint (> 15% deteriorated paint)
1.8% (2/1 12)
0.0% (0/102)
1.8% (2/109)
16.1% (18/112)
67.9% (76/1 12)
7.6% (8/105)
7.7% (8/104)
0.0% (0/52)
88.4% (38/44)
3.6% (4/1 12)
1.0% (1/1 02)
2.8% (3/1 09)
22.3% (25/1 12)
75.9% (85/1 12)
7.6% (8/105)
7.7% (8/104)
0.0% (0/52)
88.4% (38/44)
Performance Characteristics
Sensitivity
(LCB, UCB)
Specificity
(LCB. UCB)
Positive Predictive Value
(LCB. UCB)
Negative Predictive Value
(LCB UCB)
75.0%
(53.3%, 90.2%)
30.7%
(21.3%. 41.4%)
22.8%
(14.1%, 33.6%)
81.8%
(64.5%. 93.0%)
83.3%
(62.6%, 95.3%)
22.7%
(14.5%, 32.9%)
22.7%
(14.5%, 32.9%)
83.3%
(62.6%. 95.3%)
8.0% (9/1 12)
3.9% (4/102)
5.5% (6/109)
27.7% (31/112)
83.0% (93/1 12)
7.6% (8/105)
7.7% (8/104)
0.0% (0/52)
88.4% (38/44)
91.7%
(73.0%, 99.0%)
17.0%
(9.9%, 26.6%)
23.2%
(15.1%, 32.9%)
88.2%
(63.6%. 98.5%)
Note: 1. Floor, window sill, and window well samples were
a core sample, and XRF measurements were taken
2. See Table 5-3 for definitions of sampling protocols
collected as dust wipes, soil was collected as
for paint.
A-1, A-2, and A-3.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 G-15
-------
Table G-15. Sampling Protocol B: Comparison of Various Methods of Characterizing Dust
Wipe Samples Obtained in a Full Risk Assessment, Using the Proposed Rule
Standards (XRF Paint Samples from Surfaces With > 15% Deteriorated
Paint).
# Homes included in analysis
% of Homes Failing the Risk Assessment
iff Homes Failing / # Homes)
% of Blood Samples 2 10//g/dL
Sampling Protocol Group B
B-1
(Geometric Mean)
112
56.3%
B-2
(Arithmetic Mean)
112
59.8%
B-3
(Maximum Value)
112
69.6%
21.4%
% of Homes Failing the Risk Assessment on Media Standards
(# of Homes Failing/* Homes in which samples were collected)
All Floors
Carpeted Floors Only
Uncarpeted Floors Only
Window Sill
Window Well
Soil (Average of average dripline
and average play area)
Dripline Soil Only
Play Area Soil Only
Paint (> 15% deteriorated paint)
5.4% (6/1 12)
2.9% (3/102)
3.7% (4/109)
28.6% (32/1 12)
8.9% (10/112)
2.9% (3/102)
7.3% (8/109)
32.1% (36/1 12)
NA
27.6% (29/105)
27.6% (29/105)
19.6% (22/1 12)
4.9% (5/102)
16.5% (18/109)
49.1% (55/1 12)
27.6% (29/105)
NA
NA
88.4% (38/43)
88.4% (38/43)
Performance Characteristics
Sensitivity
(LCB. UCB)
Specificity
(LCB, UCB)
Positive Predictive Value
(LCB, UCB)
Negative Predictive Value
(LCB UCB)
83.3%
(62.6%, 95.3%)
51.1%
(40.2%, 61.9%)
31.7%
(20.6%, 44.7%)
91.8%
(80.4%, 97.7%)
87.5%
(67.6%. 97.3%)
47.7%
(37.0%. 58.6%)
31.3%
(20.6%, 43.8%)
93.3%
(81.7%, 98.6%)
88.4% (38/43)
87.5%
(67.6%, 97.3%)
35.2%
(25.3%. 46.1%)
26.9%
(17.5%. 38.2%)
91.2%
(76.3%, 98.1%)
Note: 1. Floor, window sill, and window well samples were collected as dust wipes, soil was collected as a
core sample, and XRF measurements were taken for paint. Window well samples are not included
in the Proposed Rule sampling scheme.
2. See Table 5-4 for definitions of sampling protocols B-1, B-2, and B-3.
3. NA indicates that these samples were not included in the analysis.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 G-16
-------
Table G-16. Sampling Protocol B: Comparison of Various Methods of Characterizing Dust
Wipe Samples, Using the Interim Guidance Standards (No Soil or Paint
Sampling).
# Homes included in analysis
% of Homes Failing the Risk Assessment
(# Homes Failing / # Homes)
% of Blood Samples 2 10//g/dL
Sampling Protocol Group B
B-1
(Geometric Mean)
112
67.9%
B-2
(Arithmetic Mean)
112
75.9%
B-3
(Maximum Value)
112
83.0%
21.4%
% of Homes Failing the Risk Assessment on Media Standards
(# of Homes Failing/* Homes in which samples were collected)
All Floors
Carpeted Floors Only
Uncarpeted Floors Only
Window Sill
Window Well
Soil
Dripline Soil Only
Play Area Soil Only
Paint
1.8% (2/1 12)
0% (0/102)
1.8% (2/1 09)
16.1% (18/112)
67.9% (76/1 12)
3.6% (4/1 12)
1% (1/1 02)
2.8% (3/109)
22.3% (25/112)
75.9% (85/1 12)
8% (9/1 12)
3.9% (4/102)
5.5% (6/109)
27.7% (31/112)
83% (93/1 12)
NA
NA
NA
NA
Performance Characteristics
Sensitivity
(LCB, UCB)
Specificity
(LCB, UCB)
Positive Predictive Value
(LCB, UCB)
Negative Predictive Value
(LCB, UCB)
70.8%
(48.9%, 87.4%)
33.0%
(23.3%, 43.8%)
22.4%
(13.6%, 33.4%)
80.6%
(64.0%, 91.8%)
79.2%
(57.8%, 92.9%)
25.0%
(16.4%, 35.4%)
22.4%
(14.0%. 32.7%)
81.5%
(61.9%, 93.7%)
91.7%
(73.0%, 99.0%)
19.3%
(11.7%, 29.1%)
23.7%
(15.5%, 33.6%)
89.5%
(66.9%, 98.7%)
Note: 1. Floor, window sill, and window well samples were collected as dust wipes.
2. See Table 5-4 for definitions of sampling protocols B-1. B-2, and B-3.
3. NA indicates that these samples were not included in the analysis.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 G-17
-------
Table G-17. Sampling Protocol B: Comparison of Various Methods of Characterizing Dust
Wipe Samples, Using the Proposed Rule Standards (No Soil or Paint Samples).
1.
=^=====^==
# Homes included in analysis
% of Homes Failing the Risk Assessment
(# Homes Failing / # Homes)
% of Blood Samples * 10 //g/dL
Sampling Protocol Group B
B-1
(Geometric Mean)
^s^^a: ^^^^^s^a
112
31.3%
B-2
(Arithmetic Mean)
112
35.7%
B-3
(Maximum Value)
112
57.1%
21.4%
% of Homes Failing the Risk Assessment on Media Standards
(« of Homes Failing/* Homes in which samples were collected)
All Floors
Carpeted Floors Only
Uncarpeted Floors Only
Window Sill
Window Well
Soil (Average of average dripline and
average play area)
Dripline Soil Only
Play Area Soil Only
Paint
5.4% (6/1 12)
2.9% (3/102)
3.7% (4/109)
28.6% (32/1 12)
8.9% (10/1 12)
2.9% (3/102)
7.3% (8/109)
32.1% (36/1 12)
19.6% (22/1 12)
4.9% (5/102)
16.5% (18/1 09)
49.1% (55/1 12)
NA
NA
NA
NA
NA
Performance Characteristics
Sensitivity
(LCB, UCB)
Specificity
(LCB, UCB)
Positive Predictive Value
(LCB, UCB)
Negative Predictive Value
(LCB. UCB)
54.2%
(32.8%, 74.4%)
75.0%
(64.6%, 83.6%)
37.1%
(21.5%, 55.1%)
85.7%
(75.9%, 92.6%)
*^^=g^=^^^s^^^
62.5%
(40.6%, 81.2%)
71.6%
(61.0%, 80.7%)
37.5%
(22.7%. 54.2%)
87.5%
(77.6%, 94.1%)
75%
(53.3%, 90.2%)
47.7%
(37%, 58.6%)
28.1%
(17.6%. 40.8%)
87.5%
(74.8%. 95.3%)
Note: 1. Floor, window sill, and window well samples were collected as dust wipes.
2. See Table 5-4 for definitions of sampling protocols B-1, B-2, and B-3.
3. NA indicates that these samples were not included in the analysis.
Draft Report - Do Not Quote, Cite. Copy or Distribute
February 15, 1999 G-18
-------
Table G-18. Sampling Protocol Group C: Comparison of Full Risk Assessment Outcome
to a Lead Hazard Screen Outcome. Using the Interim Guidance Standards
(XRF Paint Samples From Surfaces With > 15% Deteriorated Paint).
1=====^====
# Homes included in analysis
% of Homes Failing the Risk Assessment
(# Homes Failing / # Homes)
% of Blood Samples 2 10 //g/dL
Sampling Protocol Group C
C-1
(Risk Assessment)
112
84.8%
C-2
(Lead Hazard Screen)
112
83.0%
21.4%
% of Homes Failing the Risk Assessment on Media Standards
(# of Homes Failing/* Homes in which samples were collected)
All Floors
Uncarpeted Floors Only
Window Sill
Soil
8.0% (9/1 12)
3.9% (4/102)
5.5% (6/109)
27.7% (31/1 12)
83.0% (93/1 12)
7.6% (8/105)
7.7% (8/104)
0% (0/52)
88.4% (38/43)
8.9% (10/1 12)
2.9% (3/102)
7.3% (8/109)
NA
82.1% (92/1 12)
NA
NA
NA
88.4% (38/43)
Performance Characteristics
Sensitivity
(LCB, UCB)
Specificity
(LCB, UCB)
Positive Predictive Value
(LCB. UCB)
Negative Predictive Value
91.7%
(73.0%, 99.0%)
17.0%
(9.9%, 26.6%)
23.2%
(15.1%, 32.9%)
88.2%
(63.6%. 98.5%)
87.5%
(67.6%, 97.3%)
18.2%
(9.9%, 26.6%)
22.6%
(14.6%, 32.4%)
84.2%
(60.4%. 96.6%)
Note: 1. Floor, window sill, and window well samples were collected as dust wipes, soil was collected as
core sample, and XRF measurements were taken for paint.
2. See Table 5-5 for definitions of sampling protocols C-1 and C-2.
3. NA indicates that these samples were not included in the analysis.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 G-19
-------
Table G-19. Sampling Protocol Group C: Comparison of Full Risk Assessment Outcome
to a Lead Hazard Screen Outcome, Using the Proposed Rule Standards (XRF
Paint Samples From Surfaces With >15% Deteriorated Paint).
# Homes included in analysis
% of Homes Failing the Risk Assessment
(if Homes Failing / # Homes)
% of Blood Samples 2 10/sg/dL
Sampling Protocol Group C
C-1
(Risk Assessment)
112
59.8%
C-2
(Lead Hazard Screen)
112
44.6%
21.4%
% of Homes Failing the Risk Assessment on Media Standards
(# of Homes Failing/if Homes in which samples were collected)
All Floors
Carpeted Floors Only
Uncarpeted Floors Only
Window Sill
Window Well
Soil (Average of average dripline
and average play area)
Dripline Soil Only
Play Area Soil Only
Paint (> 1 5% deteriorated paint)
8.9% (10/1 12)
2.9% (3/102)
7.3% (8/109)
32.1% (36/1 12)
NA
27.6% (29/105)
NA
NA
88.4% (38/43)
30.4% (34/1 12)
10.8% (11/102)
26.6% (29/109)
NA
NA
NA
NA
NA
88.4% (38/43)
Performance Characteristics
Sensitivity
(LCB, UCB)
Specificity
(LCB, UCB)
Positive Predictive Value
(LCB, UCB)
Negative Predictive Value
(LCB UCB)
87.5%
(67.6%. 97.3%)
47.7%
(37.0%, 58.6%)
31.3%
(20.6%. 43.8%)
93.3%
(81.7%, 98.6%)
70.8%
(48.9%, 87.4%)
62.5%
(51.5%, 72.6%)
34.0%
(21.2%, 48.8%)
88.7%
(78.0%. 95.3%)
Note: 1. Floor, window sill, and window well samples were collected as dust wipes, soil was collected as a
core sample, and XRF measurements were taken for paint.
2. See Table 5-5 for definitions of sampling protocols C-1 and C-2.
3. NA indicates that these samples were not included in the analysis.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 G-20
-------
Table G-20. Sampling Protocol B: Comparison of Various Methods of Characterizing Dust
Wipe Samples, Using the Interim Guidance Standards (No Window Well or
Paint Sampling).
# Homes included in analysis
% of Homes Failing the Risk Assessment
(# Homes Failing / # Homes)
% of Blood Samples * 10/sg/dL
Sampling Protocol Group B
B-1
(Geometric Mean)
112
22.3%
B-2
(Arithmetic Mean)
112
29.5%
B-3
(Maximum Value)
112
36.6%
21.4%
% of Homes Failing the Risk Assessment on Media Standards
(# of Homes Failing/* Homes in which samples were collected)
All Floors
Carpeted Floors Only
Uncarpeted Floors Only
Window Sill
Window Well
Soil
Dripline Soil Only
Play Area Soil Only
Paint
1.8% (2/1 12)
0% (0/102)
1.8% (2/109)
16.1% 118/112)
3.6% (4/1 12)
1% (1/102)
2.8% (3/109)
22.3% (25/1 12)
NA
7.6% (8/105)
7.7% (8/104)
0% (0/52)
7.6% (8/105)
7.7% (8/104)
0% (0/52)
8% (9/1 12)
3.9% (4/102)
5.5% (6/109)
27.7% (31/1 12)
7.6% (8/105)
7.7% (8/104)
0% (0/52)
NA
Performance Characteristics
Sensitivity
(LCB, UCB)
Specificity
(LCB%, UCB)
Positive Predictive Value
(LCB%, UCB)
Negative Predictive Value
(LCB% UCB)
33.3%
(15.6%, 55.3%)
80.7%
(70.9%, 88.3%)
32.0%
(14.9%, 53.5%)
81.6%
(71 9% 89.1%)
45.8%
(25.6%, 67.2%)
75%
(64.6%, .0 83.6%)
33.3%
(18%, 51.8%)
83.5%
(73.5%, 90.9%)
58.3%
(36.6%, 77.9%)
69.3%
(58.6%, 78.7%)
34.1%
(20.1%. 50.6%)
85.9%
(75.6%. 93%)
Note: 1. Floor and window sill samples were collected as dust wipes and soil was
2. See Table 5-4 for definitions of sampling protocols B-1, B-2, and B-3.
3. NA indicates that these samples were not included in the analysis.
collected as a core.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 G-21
-------
Table G-21. Sampling Protocol Group B: Comparison of Various Methods of
Characterizing Dust Wipe Samples, Using the Proposed Rule Standards (No
Window Well or Paint Samples).
Sampling Protocol Group B
B-3
(Maximum Value)
B-2
(Arithmetic Mean)
(Geometric Mean)
ff Homes included in analysis
% of Homes Failing the Risk Assessment
(# Homes Failing / # Homes)
% of Blood Samples 2 10//g/dL
% of Homes Failing the Risk Assessment on Media Standards
(# of Homes Failing/* Homes in which samples were collected)
All Floors
Carpeted Floors Only
Uncarpeted Floors Only
Window Sill
Window Well
Soil (Average of average dripline
and average play area)
Dripline Soil Only
Play Area Soil Only
Paint
5.4% (6/112)
2.9% (3/102)
3.7% (4/109)
28.6% (32/112)
8.9% (10/112)
2.9% (3/102)
7.3% (8/109)
32.1% (36/112)
19.6% (22/112)
4.9% (5/102)
16.5% (18/109)
49.1% (55/112)
NA
27.6% (29/105)
05) I
27.6% 129/105)
NA
27.6% (29/105)
NA
NA
Performance Characteristics
Sensitivity
(LCB, UCB)
Specificity
(LCB%, UCB)
Positive Predictive Value
(LCB%. UCB)
79.2%
(57.8%, 92.9%)
60.2%
(49.2%, 70.5%)
35.2%
(22.7%, 49.4%)
87.5%
(67.6%, 97.3%)
56.8%
(45.8%. 67.3%)
35.6%
(23.6%. 49.1%)
87.5%
(67.6%, 97.3%)
38.6%
(28.4%, 49.6%)
28.0%
(18.2%. 39.6%)
Negative Predictive Value
(LCB%. UCB)
91.4%
(81.0%. 97.1%)
94.3%
184.3%. 98.8%)
91.9%
(78.1%. 98.3%)
Note: 1. Floor and window sill samples were collected as dust wipes and soil was collected as a core.
Window well samples are not required under the Proposed Rule.
2. See Table 5-4 for definitions of sampling protocols B-1. B-2, and B-3.
3. NA indicates that these samples were not included in the analysis.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 G-22
-------
Table G-22. Sampling Protocol Group B: Comparison of Various Methods of
Characterizing Dust Wipe Samples, Using the Interim Guidance Standards
(No Paint Samples).
# Homes included in analysis
% of Homes Failing the Risk Assessment
(# Homes Failing / # Homes)
% of Blood Samples 2. 10pg/dL
Sampling Protocol Group B
B-1
(Geometric Mean)
112
69.6%
B-2
(Arithmetic Mean)
112
77.7%
B-3
(Maximum Value)
112
83.9%
21.4%
% of Homes Failing the Risk Assessment on Media Standards
(# of Homes Failing/* Homes in which samples were collected)
All Floors
Carpeted Floors Only
Uncarpeted Floors Only
Window Sill
Window Well
Soil
Dripline Soil Only
Play Area Soil Only
Paint
1.8% (2/112)
0% (0/102)
1.8% (2/1 09)
16.1% (18/112)
67.9% (76/1 12)
7.6% (8/105)
7.7% (8/104)
0% (0/52)
3.6% (4/1 12)
1% (1/102)
2.8% (3/109)
22.3% (25/1 12)
75.9% (85/1 12)
7.6% (8/105)
7.7% (8/104)
0% (0/52)
8% (9/1 12)
3.9% (4/102)
5.5% (6/109)
27.7% (31/1 12)
83% (93/112)
7.6% (8/105)
7.7% (8/104)
0% (0/52)
NA
Performance Characteristics
Sensitivity
(LCB, UCB)
Specificity
<(LCB%, UCB)
Positive Predictive Value
((LCB%. UCB)
Negative Predictive Value
(|LCB% UCB)
75%
(53.3%, 90.2%)
31.8%
(22.3%. 42.6%)
23.1%
(14.3%, 34%)
82.4%
(65.5%, 93.2%)
83.3%
(62.6%, 95.3%)
23.9%
(15.4%, 34.1%)
23.0%
(14.6%, 33.2%)
84.0%
(63.9%. 95.5%)
91.7%
(73.0%. 99.0%)
18.2%
(10.8%, 27.8%)
23.4%
(15.3%, 33.3%)
88.9%
(65.3%. 98.6%)
Note: 1. Floor, window sill, and window well samples were collected as dust wipes and soil was
collected as a core sample.
2. See Table 5-4 for definitions of sampling protocols B-1, B-2, and B-3.
3. NA indicates that these samples were not included in the analysis.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 G-23
-------
Table G-23. Sampling Protocol C: Comparison of Lead Hazard Screen Outcome, Using
the Interim Guidance Standards and the Proposed Rule Standards (XRF Paint
Samples From Surfaces With >5% Deteriorated Paint).
# Homes included in analysis
% of Homes Failing the Risk Assessment
(# Homes Failing / # Homes)
% of Blood Samples * 10pg/dL
Sampling Protocol Group C (Lead Hazard Screen)
Interim Guidance
112
83.9%
Proposed Rule
112
67.0%
21.4%
% of Homes Failing the Risk Assessment on Media Standards U Media Standard)
(# of Homes Failing/0 Homes in which samples were collected)
All Floors
Carpeted Floors Only
Uncarpeted Floors Only
Window Sill
Window Well
Soil
Dripline Soil Only
Play Area Soil Only
Paint (> 5% deteriorated)
8.9% (10/1 12)
2.9% (3/102)
7.3% (8/109)
NA
82.1 (92/112)
NA
NA
NA
77.3% (68/88)
30.4% (34/1 12)
10.8% (11/1 02)
26.6% (29/109)
64.3% (72/1 12)
NA
NA
NA
NA
77.3% (68/88)
Performance Characteristics
Sensitivity
(LCB, UCB)
Specificity
(LCB, UCB)
Positive Predictive Value
(LCB, UCB)
Negative Predictive Value
(LCB, UCB)
87.5%
(67.6%, 97.3%)
17.0%
(9.9%, 26.6%)
22.3%
(14.4%. 32.1%)
83.3%
(58.6%. 96.4%)
91.7%
(73%. 99%)
25.0%
(16%, 35%)
25.0%
(16%, 35%)
91.7%
(73%. 99%)
Note: 1. Floor, window sill, and window well samples were collected as dust wipes.
2. NA indicates that these samples were not included in the analysis.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 G-24
-------
APPENDIX H
Summary Error Probability Tables and Graphs
for the Interim Guidance Standards
Draft Report - Do Not Quote. Cite, Copy or Distribute February 11, 1999 H-1
-------
Error Pr.fc.Wltr o*.r . Ron«. of Tru. Condltlooi
Uiia* floor. Du* Buk Aootormonl SUj*Ur4
(Tkroo Souploi)
40 go M 100 180 1*0 1*°
Tru. Hou*. Coo»»trlc M«*n Durt U«d Loodlnf (m/ft2) on Floor!
Error Fntobllltj cnv • UK* >1 Tnu
tOO 300 400 MO WO TOO MO
Tra Boil- OoiMlr* «u> On* Lnd Imdlu lin/Ml an IUito» «ll»
Error Probability *w o B*n|« •! Tru
Uiini Ploon Ihut U«d H*Mr4 SCTMB 9UoiUH
Krror ProbmbUltr 9*v • ba|« of Tnu CoodlUooJ
U.lni flndow SU1« ItiMl U*d tUMrd SCTMO SUwUrd
MO 300 400 600 (00 TOO
T™ Hou» C.om.lrtc M-j Dull LMd U»dto| (m/M) «»
Krror PrgbabUltr imr •
U«nf rindo* wtu« Dwl KUk A
400 CM
Tra. Itea. l^om.lrUi Iton Pint
IOM ISM 1400
Ijrftol (m/M) o» 1i»tow '•!!«
Error rrobtbiUtr
-------
«f Tn» CaodiUonl
Tnw HMIM Cmnwtrlc UHH Duit Utd iMdln* (uf/fU) on Hoon
Krror Prokmbliltj or«r • R*m. of Tnt* C*ndltUiu
L'iu]« Floon Du.t Utd rUurd Sc
Tni« HOUM Cmo>*trtc ««*D Duit U.d LMdlni (uf/fU) on Hoar.
tmr Probkbtlltr otv • Ruff* 01 Trua CoodlUoot
Uiloc Wlodov 3Uli Durt tl*k iMMonrat SUneUrd
Tnu HOUM CMiMtrtc MMB Ihut U«d Lotdlof (u«/R2} on Window SUii
Km>r Prob.bllltj mr . Un<« of Tni* Coodltteu
Ittlnf Vlndov Sim Duct LMd Huwd SCTMO S
MOaOO«MM0800TOOeOOMO 1000
Tni* HOUM C.om.lrtc If«u Ihut Lrad LowUn| (m/U) « Wlado« 3Ub
i fIndo. I.U» Durt Kifk J
Tru. HOUM C«o
-------
trror PntaMttlj *1 LoAdlnc (u«/rt2) oc Floor*
d H.«rtl SCTMB SUnb*bllUr *rw • lu<« el Tru. Condition*
IMnj rmdo. Sib Durt Riik Jw.M
(THrot Sunploi)
. HOUM CMDMtrte MMB Put L.m [MdUif (nc/tu) M Window su*
ProtabUltr °
SUli Ih
0 1DO WO SW 400 WO MO TOO
Tni. HOUM C.om«tri= II«U [hut L
Error Pnba.Uitf vrm • Rup •( To- Condition.
Udo« Wtodmr W«U« DuK Rbk AMonnwat SUadud
H WO 100 SOO 1000 IZOO 1*00
TrU. ROHM S«m.Uic HMD Du.t Uul L—dln* (<«/fU) *n Window W.lli
Irror ProWbdilj OTW . Rue* of Truo Cwditiom.
UilDf Window Wrll« Duft U*d Huvrl ScTWD StuuUfd
DO 400 MO 800 1000 1200 It
TVu. HOUM C*,m.irtr Uou Dual L*«d iMdlnf (ut/Kt) MI Had** W.Ik
Figure H-3. Comparison of Risk Assessment and "Compound" Lead Hazard Screen
Geometric Mean, Arithmetic Mean, and Maximum Value Error Probabilities
for Three Floor. Window Sill, and Window Well Dust Samples Using the -
Interim Guidance Standards - Variance Components from the Rhode Island
Department of Health Homes.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 H-4
-------
brvr Probability «nr • l
U4nf riMn Durt XUfc
* •* Tru* CondlUww
40 U 80 100 110 140 IM ISO
True BMIM CwOMtric lUu Durt U*d Lo«dlfl| (nf/ttZ) MI Floon
trror PreMbUltj vnr » lUiif. •!
U«iD4 n»on Durt U*a Bkurd 3
40 H M 100 IB) 140 180
Tnia HOUM CMOwtrte HMO Duit L»»d iMdlai (u|/ft2) on Floon
trror Prob.^lj w . »«>,. W T
iOMMtl
(Pwir Sunft
Ho un 3«o m. tile Ibu DiMt U»d LaMlUl4 («c/fU) u flnilow SUb
Irror FrotebllltT o-rwr • Ku|< of T™
Ufto« rmdow SUto Duit LMd H-wid 9crMa
l*Um*t«n: Gwuwtrio H
aoowwBooiooTooeoowoiooc
c HMB Ihut LMd L«dln« (u«/rU) on Wlado* Wb
[rr*r P
Uttoi Window f tlli DMA RUk AMMI
(r«UT Sunplw)
TtiM HOUM CMxnrtrtc MMA Durt L
looo
d LMdtaf (uc/ft2) •
00 400 100
True HOUM CMiMtrtc UMB D
800 1000 1100 1400
it LMd LMdtac (oc/fU) M Ylnfev fill.
Figure H-4. Comparison of Risk Assessment and "Compound" Lead Hazard Screen
Geometric Mean, Arithmetic Mean, and Maximum Value Error Probabilities
for Four Floor. Window Sill, and Window Well Dust Samples Using the
Interim Guidance Standards - Variance Components from the Rhode Island
Department of Health Homes.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 H-5
-------
Error Probability over a Rang* of Trua Condition*
U*lng Floor* Dust Lead Hazard Screen Standard
(Three Sample*}
1.0-
O.B-
00
O 7
oa-
06
O *
O.3 •
O.2
01
o.o
Estimator*:
Geometric Mean
Arithmetic Mean
Maximum
10 20 30 40 GO 60 70
True Houee Geometric Uean Du«t Laad Loading (ug/fta) °" Floor*
90 1OO
(Three Sample*}
o.o
O.8
O.7
0.6
O-5
O,4
0.3
0.2
0.1
O.O
Estimator*:
Geometric: Mean
Arithmetic Mean
Maximum
1OO SOO 3OO *OO
True Hou*e Geometric Uean Du*t Laad Loading (ug/tta) on Window SL11*
1OO 2OO 300 40O SOO
True Houee Geometric Mean Du*t Lead Loading (ug/HE) on Window Walla
Figure H-5. Comparison of "Simple" Lead Hazard Screen Geometric Mean, Arithmetic
Mean, and Maximum Value Error Probabilities for Three Floor and Window
Well Dust Samples Using the Interim Guidance Standards - Variance
Components from the Rochester Lead-in-Dust Study Homes.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 H-6
-------
Error Probability over a Rang* of Trua Condition*
Uiing Floors Dust Lead Hazard Screen Standard
(Four Sample*)
2O 3O 4O BO BO 7O BO
True Hou*e Geometric M«on Dual Lead Loading (ug/ftZ] on Floor*
Error Probability over a Rang* of True Condition*
U*lng Window Silt* Du-t Lead Hazard Screen Standard
(Four Sample*)
1 .0 -
0.0 -
on -
O.7 -
3 0.6-
I
E 0.0
I
0.3
0.2 •
O. 1
o.o
Estimator*:
Geometric Mean
• - Arithmetic Mean
Maximum
400
low Sill*
U*ing Window Well* Du*t Laad Hazard Screen Standard
(Four Sample.*)
1.0
O.B
0.0
0.7
o.e
o.a
0.4
0.3
02
0.1
o.o
E*timator>:
Geometric Mean
Arithmetic Mean
Maximum
1OO ZOO 3OO 4OO COO 0OO 7OO
True House Geometric Mean Du*t Lead Loading (ug/ft2) on Window Well*
Figure H-6. Comparison of "Simple" Lead Hazard Screen Geometric Mean, Arithmetic
Mean, and Maximum Value Error Probabilities for Four Floor and Window
Well Dust Samples Using the Interim Guidance Standards - Variance
Components from the Rochester Lead-in-Dust Study Homes.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 H-7
-------
Error Probability ov«r a Rang* of Tru» Condition*
Using Floor* Dust Lead Hazard Screen Standard
(Two Samples)
1.0
o.e
O.B
0.7
0.8
O.S
0.4
0.3
02
O.I
0.0
Estimator*.:
• Geometric Mean
Arithmetic Uaan
Maximum
20 3O 40 6O 60 70 BO
Trua Hou». Caomalric Maan Dual Laad Loading (ug/fl2) on Floor*
BO 100
1.0-
O.9 -
O.B -
O.7 -
0.8-
O.3 -
O.Z-
0.1 -
o.o -
(Two Samples)
Caomatrlo Mean
Error Probability over a Ranga of Trua Condition*
Uslna Window Wall* Dust Laad Hazard Screen Standard
(Two Samples)
1.0
0.9
O.B
0.7
0.8
0.6
04
0.3
0.2
0.1
0.0
Estimators:
10O 2OO 3OO 4OO COO COO TOO
Trua HOUB* Geom.ti-ic Mean Du«t Laad Loading (ug/ftB) on Window Wall*
Figure H-7. Comparison of "Simple" Lead Hazard Screen Geometric Mean, Arithmetic
Mean, and Maximum Value Error Probabilities for Two Floor and Window
Well Samples Using the Interim Guidance Standards - Variance Components
from the Rhode Island Department of Health Data.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 H-8
-------
Error Probability i
UsLns Flo
(Thi
r a Rang* of Trua Condition*
aa Samples)
1.0
O.O
o.e
0.7
I ...
1 »•«
1 -
0.3
O.2
O.I
O.O
Estimator*:
Geometric Mean
3O 40 BO 8O 70 BO
urn* Geometric Mean Duet Lead Loading (ug/ft2) on Floor*
l.O
O.9
O.6
0.7
o.e
I °s
O.4
0.3
O.Z
0.1
0.0
Error Probability over a Rang* of True Condition*
U*lng Window Sill* D\*»t Lead Hazard Screen Standard
(Three Sample*)
Estimator*:
- Arithmetic Mean
Maximum
100
True Hou
2OO 3OO 4OO
. Geometric Maan Du*t Lead Loading (ug/ftZ) on Window Sill*
Error Probability over a Range of True Condition*
U»lng Window Well* Du»t Lead Hazard Screen Standard
(Three Samples)
1 .O
0.8
O.O
0.7
o e
o.o
O.4
O.3
0-3
0.1
O.O
Estimator":
Geometric Mean
Arithmetic Mean
Maximum
1OO 200
True Houae Ge
3OO *OO BOO OOO TOO
netric Mean Duet Lead Loading (ug/ftZ) on Window Walla
Figure H-8. Comparison of "Simple" Lead Hazard Screen Geometric Mean, Arithmetic
Mean, and Maximum Value Error Probabilities for Three Floor and Window
Well Dust Samples Using the Interim Guidance Standards - Variance
Components from the Rhode Island Department of Health Data.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 H-9
-------
Error Probability over * Range of True Condition*
U«ing Floors Dual Lead Hazard Screen Standard
(Four Sample*)
True HOVJ-. G.om-t
40 BO 60 70
•ic M«nn Dual L*»d Loading (ug/ftZ) '
l.O
0.9
O.B
0-7
0.6
0.6
0.4
0-3
0.2
0.1
O.O
Error Probability over a Range of Tru
U*lng Window Sill* Du.t L«d Haz«rd Sc
(Four Sample*}
••n Standard
Estimator*:
Geometric Mean
• - Arithm-tic Mean
Maximum
1OO
True Hoi
2OO 3OO
» Geometric Uean Du«t Lead Loading (
4OO
I on Window Sill*
Error Probability over a Range of
U«lng Window Well* Du«t Lead Hazar
(Four Sample*)
1.0 -
O.9 -
O.B •
0.7
O.O
O.6
O.*
O.3
0.2
0.1
0.0
Eetlmator*:
Geometric Uean
Arithmetic Uean
Maximum
JOO 2OO 3OO *OO OOO
True Houee Geometric Mean Duel Lead Loading (ug/ft2)
000
[>n Wlndo
Figure H-9. Comparison of "Simple" Lead Hazard Screen Geometric Mean, Arithmetic
Mean, and Maximum Value Error Probabilities for Four Floor and Window
Well Dust Samples Using the Interim Guidance Standards - Variance
Components from the Rhode Island Department of Health Data.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 H-10
-------
Table H-1. Comparison of Risk Assessment and "Compound" Lead Hazard Screen Error
Probabilities for Each Statistic Over a Range of Assumed "True" House Lead
Levels for the Two. Three, and Four Floor Dust Samples Using the Interim
Guidance Standards1 - Variance Components from the Rhode Island
Department of Health Data.
Assessment
'Compound*
Lead Hazard
Screen
Risk
Assessment
Number
of
Samples
2
3
4
2
3
4
Assumed
•True"
House
Floor Dust
Lead
Loading
(l/g/ft'l
50
100
200
50
100
200
50
100
200
50
100
200
50
100
200
50
100
200
Error Probability of the Statistic
Type 1 Error
Arithmetic
Mean
0.120
0.538
.
0.122
0.621
.
0.124
0.703
.
0.207
0.593
0.192
0.652
.
0.172
0.717
.
Geometric
Mean
0.061
0.439
.
0.038
0.462
0.025
0.475
.
0.122
0.500
.
0.077
0.500
.
0.050
0.500
•
Maximum
Value
0.276
0.718
.
0.435
0.867
0.563
0.936
.
0.368
0.750
.
0.498
0.875
.
0.601
0.938
•
Type II Error
Arithmetic
Mean
•
0.466
0.097
.
0.358
0.048
.
0.345
0.021
•
0.411
0.092
•
0.334
0.048
•
0.329
0.020
Geometric
Mean
•
0.561
0.131
•
0.538
0.079
•
0.525
0.050
•
0.500
0.122
•
0.500
0.077
•
0.500
0.050
Maximum
Value
•
0.282
0.044
•
0.133
0.009
•
0.064
0.002
•
0.250
0.042
0.125
0.009
•
0.063
0.002
1 The floor dust wipe standard at which a home fails the assessment was assumed to be 100 /sg/ft* for
the risk assessment and 50//g/ft' for the lead hazard screen.
Draft Report - Do Not Quote, Cite. Copy or Distribute
February 15. 1999 H-11
-------
Table H-2. Comparison of Risk Assessment Error Probabilities for Each Statistic Over a
Range of Assumed "True" House Lead Levels for Two, Three, and Four
Window Sill Dust Samples Using the Interim Guidance Standards1 - Variance
Components from the Rhode Island Department of Health Data.
Assessment
"Compound"
Lead
Hazard
Screen
Risk
Assessment
— ^— ^^^=
Number
of
Samples
2
3
4
2
3
4
:^=^=^=
Assumed
"Trufi*
House
Window Sill
Dust Lead
Loading
U/g/ftM
=^=^^^=
250
500
1.000
250
500
1.000
250
500
1.000
250
500
1,000
250
500
1,000
250
500
1,000
==^==^=— =— =•
Error Probability of the Statistic
Type 1 Error
Arithmeti
c Mean
=^==
0.205
0.526
.
0.257
0.638
.
0.311
0.745
0.337
0.619
m
0.375
0.697
.
0.403
0.778
•
Geometri
c Mean
==^=
0.110
0.390
.
0.086
0.414
.
0.069
0.431
•
0.220
0.500
.
0.173
0.500
.
0.138
0.500
Maximum
Value
^=^^^^=
0.375
0.686
.
0.566
0.853
.
0.703
0.931
•
0.500
0.750
.
0.646
0.875
.
0.750
0.938
•
Type II Error
Arithmetic
Mean
==
0.481
0.185
•
0.345
0.097
.
0.317
0.047
•
0.386
0.151
.
0.289
0.084
.
0.277
0.043
Geometric
Mean
•
0.610
0.268
•
0.586
0.197
•
0.569
0.150
•
0.500
0.220
•
0.500
0.173
•
0.500
0.138
Maximum
Value
•
0.314
0.103
•
0.147
0.028
•
0.069
0.008
•
0.250
0.086
•
0.125
0.025
•
0.063
0.007
Note: The lead hazard screen does recommend window sills be sampled.
1 The window sill dust wipe standard at which a home fails the assessment was assumed to be 500 //g/ft
for the risk assessment.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15. 1999 H-12
-------
Table H-3. Comparison of Risk Assessment and "Compound" Lead Hazard Screen Error
Probabilities for Each Statistic Over a Range of Assumed "True" House Lead
Levels for Two. Three, and Four Window Well Dust Samples Using the Interim
Guidance Standards1 - Variance Components from the Rhode Island
Department of Health Data.
=====
Assessment
======
'Compound*
Lead Hazard
Screen
Risk
Assessment
-— =— =
=====
Number
of
Samples
=====
2
3
4
2
3
4
=====
======
Assumed
•True"
House
Window
Well Dust
Lead
Loading
big/ft1)
=====
400
800
1.600
400
800
1,600
400
800
1.600
400
800
1.600
400
800
1.600
400
800
1,600
Error Probability of the Statistic
Type 1 Error
Arithmetic
Mean
=====
0.245
0.490
,
0.303
0.629
.
0.307
0.720
.
0.38S
0.584
m
0.424
0.697
.
0.405
0.756
=====
Geometric
Mean
=====
0.115
0.385
.
0.091
0.409
.
0.074
0.426
.
0.230
0.500
,
0.183
0.500
.
0.148
0.500
=====
Maximum
Value
=====
0.383
0.682
.
0.576
0.851
.
0.713
0.930
.
0.511
0.750
.
0.658
0.875
.
0.761
0.938
=====
Type II Error
Arithmetic
Mean
=====
0.485
0.196
.
0.343
0.112
.
0.313
0.050
•
0.385
0.161
•
0.285
0.097
.
0.271
0.047
=====
Geometric
Mean
===
0.615
0.283
•
0.591
0.211
•
0.574
0.163
•
0.500
0.230
•
0.500
0.183
•
0.500
0.148
=====
Maximum
Value
=====
0.318
0.110
•
0.149
0.030
•
0.070
0.009
•
0.250
0.090
•
0.125
0.027
•
0.063
0.008
1 The window well dust wipe standard at which a home fails the assessment was assumed to be 800
;/g/ft2 for the risk assessment and 400 A/g/ftJ for the lead hazard screen.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 H-13
-------
Table H-4. Comparison of Two. Three, and Four Side of House/Foundation Soil Samples
Error Probabilities for Each Statistic Over a Range of Assumed "True" House
Lead Levels Using the Interim Guidance Standards1 - Variance Components
from the Rhode Island Department of Health Data.
=^=^=^
Location
=^=^=
Side of
House/
Foundation
==^=
Number
of
Samples
^^^^^^=
2
3
4
Assumed
'True* House
Soil Lead
Concentration
(pprrt)
==^=:
2.500
5.000
7,500
2.500
5,000
7.500
2,500
5,000
7,500
Error Probability of the Statistic
Type 1 Error
Arithmetic
Mean
=^=^=
0.262
0.605
0.271
0.668
.
0.265
0.745
Geometric
Mean
=:^=^=
0.168
0.500
.
0.119
0.500
.
0.086
0.500
Maximum
Value
0.434
0.750
.
0.574
0.875
.
0.680
0.938
•
Type II Error
Arithmetic
Mean
•
0.398
0.229
.
0.313
0.156
•
0.304
0.082
Geometric
Mean
•
0.500
0.286
•
0.500
0.245
•
0.500
0.213
^^^^^^=
Maximum
Value
^=^^^=^
0.250
0.119
•
0.125
0.041
•
0.063
0.014
=^=^
The soil standard at which a home fails the assessment was assumed to be 5,000 ppm.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15. 1999 H-14
-------
Table H-5. "Simple" Lead Hazard Screen Error Probabilities for Each Statistic Over a Range
of Assumed "True" House Lead Level for Two. Three, and Four Floor and
Window Well Dust Samples Using the Interim Guidance Standards1 - Variance
Components from the Rhode Island Study Data.
=====
Location
Floor
Window Sills
Window
Wells
Number of
Samples
2
3
4
2
3
4
2
3
4
Assumed
•True" House
Dust Lead
Loading
(pg/ft'l
30
50
70
100
30
50
70
100
30
50
70
100
100
250
400
100
250
400
500
100
250
400
500
200
600
800
200
400
600
800
200
400
600
800
Type I Error Probability of the Statistic
Geometric Mean
0.195
0.500
0.714
0.878
0.147
0.500
0.756
0.923
0.112
0.500
0.788
0.950
0.154
0.500
0.699
0.780
0.106
0.500
0.739
0.827
0.075
0.500
0.770
0.862
0.230
0.500
0.667
0.770
0.183
0.500
0.702
0.817
0.148
0.500
0.730
0 852
Arithmetic Mean
0.285
0.582
0.769
0.908
0.285
0.637
0.846
0.952
0.285
0.719
0.898
0.980
0.237
0.609
0.778
0.849
0.259
0.685
0.859
0.916
0.296
0.772
0.913
0.957
0.344
0.636
0.744
0.839
0.378
0.715
0.839
0.903
0.428
0.758
0.890
0.953
Maximum Value
0.470
0.750
0.881
0.958
0.614
0.875
0.959
0.991
0.719
0.938
0.986
0.998
0.416
0.750
0.873
0.914
0.553
0.875
0.955
0.975
0.659
0.938
0.984
0.993
0.511
0.750
0.856
0.910
0.658
0.875
0.945
0.973
0.761
0.938
0.979
0.992
1 The floor dust wipe standard at which a home fails the assessment was assumed to be 50 pg/ft1 and the window well
dust wipe standard at which a home fails the assessment was assumed to be 400//g/ft'.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15. 1999 H-15
-------
This page intentionally blank.
-------
APPENDIX I
Summary Error Probability Tables and Graphs
for the Proposed Rule Standards
Draft Report - Do Not Quote, Cite, Copy or Distribute February 15, 1999 1-1
-------
Error ProbcbUily onr • Rut* of Trua Condition*
U«un Foara Dmt Ruk AMH.m»t SUttUrd SO
Cwmetnc M**a
* «-* Arithmitic HMD
llutmum
Tnw KOUM CMiutrk MMB Dtut E«*d Lowlim (u|/fU) on noon
Error Probability mr » lw«o o( TnM CondiUou
Unm noon [hut U*d lUunl 3crt«n SUndwd tt
*•*-• lrtliun«UcM»»n
10W3040MWTOWW100
Tru« ROUH C»om«trtc UMH DtMt L*§d Loadlnf (u«/rt2) OB Floon
Error Frob«bllllr orir • K*n|« of Tru* CoadjUoai
WmdoT 9Uli Duct Riik teMHnun
(T« SwnpleiJ
100l50a»«M300350400490a«]
Tru« HOUM CMOMtric HMD Durt Ukd Uwdlaj (m/tl2) on flndow SUli
t o( Trui CoodlU«u
d SCTMD SUndwd 129 (u|/ri2)
bbmilon: Goomtlric UNO
" -»•• InlhmtUc M»4n
TTIM BOUM CMCMthc Uiu Punt Uad U»dla| (u(/ttZ) on flndo* All*
Figure 1-1. Comparison of Risk Assessment and "Compound" Lead Hazard Screen
Geometric Mean, Arithmetic Mean, and Maximum Value Error Probabilities
for Two Floor and Window Sill Dust Samples Using the Proposed Rule
Standards - Variance Components from the Rochester Lead-in-Dust Study
Homes.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 I-2
-------
Error Probability oro • tup ol In* Covtiliou
UMJ Roon Dull Eik ImHunt Sludird »(u|/IU)
0 10ZOJO«»«070K>
Tru* BOUM Cawnairic Moan Dull Lt*d Loadiii( (u|/IU) on Floon
Em>r Probability mr • I>I|I ol Tnit CoidiUam
Uilai Fbon Dull Uid Buud Scrun SUncUrt !S (m/IU)
btifluton: C«omttnc HMI
Tnu How Cnnutrie H«u Dull Uid U.din| (uj/112) on Hool
Error Probabtlitj ortr t Bu|t of friu Cooditioof
Li.iuf Tiadow 501. Dull Riik AoHOTnunl SUaiUfJ 350 (uc/ft2)
(Tbm Samples)
0 M1001M201ZS0300J»tOC«0»0
Trv. Hnin Cnmrtrtc Haul Dull Uid Loadlm I Jt'flZ) II find™ Ml
Error Probability onr • hnf • ol Irut CoodiUou
Urine Window SiU. Dull L*id H«i*rd 3CTMI1 SUodanl t2S (uf/ftZ)
CTb™ Stmplu)
Gnmitrk Uau
* *-* iriUuxetic UMB
Tnu Hou» CwDUtric Him Dull Lud U>diii| (u|/n2) on Undo! Sill
Figure 1-2. Comparison of Risk Assessment and "Compound" Lead Hazard Screen
Geometric Mean, Arithmetic Mean, and Maximum Value Error Probabilities for
Three Floor and Window Sill Dust Samples Using the Proposed Rule
Standards - Variance Components from the Rochester Lead-in-Dust Study
Homes.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 I-3
-------
1.0
O.I
01
0.7
brnr Pnbibililr onr I hop «f Imt CoDdiUoni
Uda| Ploon Diul KUk jMemMat Standard 50
(Four Suipla)
C*OIMtric Mwn
••••* Anilunitk HMD
IOZ01040SOI070MI0100
Tn» Horn C«oa»lric ttui Duit U*d Lo4diii| (u|/H2) oi Floori
o.s
0.7
1"
tna Prob.biLt j onr • tup ol Tnii Condition.
Unit noon Dial Uid Bmrt Scmn SUndiri a (m/IU)
(Tour topi-)
* *•* inltuoetjc Ma4n
0 |OnaB40NMTCMMUO
Tnu rlouM Gwmttric HMD Duit Utd Loadin (»n/tt2) *o Plmn
Error Protwbilily ntr t Hup of Tnw CoaditiODI
SlUa Dujt Rbk AiiiMimnt 3t»nd«J 2SO (u«/H2)
(Four Sunpln)
/
* •* -* Arithmetic M«»n
1D0150Z002S09003S04OI450SOO
THM Hm» G.cmeUic UMUI Duit Lwd Lo-di^ (u(/rU) en Undo* Kill
Error ProtMbLiitj onr > Rio|i ol Tnn CoodiUau
Urinf I'indow SUli Ehul Utd Huvd SCTMO Studud \& (uc/ft2)
I»litn«tor»- C«orottric Ut*n
Tnu HOUH CwnuLric VUD Dull Lud Lwdint (uc/R2) on Undo* Silli
Figure 1-3. Comparison of Risk Assessment and "Compound" Lead Hazard Screen
Geometric Mean, Arithmetic Mean, and Maximum Value Error Probabilities for
Four Floor and Window Sill Dust Samples Using the Proposed Rule Standards
Variance Components from the Rochester Study Data.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 I-4
-------
Irror Probability <"«• • Kuifli «f THM CaadlUaw
Utin* no*n DuA Rtik iMMtowat SUndwd M
30 40 M W 70 W K 100
. C-omrtric UMA Durt L»4 U*din« (ut/M) on Flow*
Tmt KDUN CMmvtrtc M»*a Dwt U«d iMdtaf (ut/fU) on F
Emr Prob.bilitf
btlmatvn: Cwnwtrtt K.*n
100 IM 100 BSO 900 350 400
Tn.. (tow C~n»Mc H«u Di»t U.d U»dia| (u«/nz) en Vladn SUli
Irror PraUbditr mr • IUn«. of Tru, Condition*
Unn« VAadew Sllli Duvt Lvtd tUurd SCTMD 9Undu4 12ft («(/rU)
W 100 ISO
Truo BOUM CMiMtrte
BO CM 300
Figure 1-4. Comparison of Risk Assessment and "Compound" Lead Hazard Screen
Geometric Mean, Arithmetic Mean, and Maximum Value Error Probabilities for
Two Floor and Window Sill Dust Samples Using the Proposed Rule Standards -
Variance Components from the Rhode Island Department of Health Homes.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 I-5
-------
10
O.I
O.I
0.7
11
05
I"
0.3
o.:
o.i
u
Error ProbibiMf onr • Rinf* of Trui CoodiUoni
Uorj Floon Dint Bik inam.nl SUiidinl »(m/K2)
Iilimiton: Coonntric »««n
. « tnUuo.tK »«a
T™ Bow Coonutnc Ibu Dull L"d U»dia| (m/!12) « n
10
0.1
0.9
0.7
0.9
I U
|M
0.3
0.2
0.1
0.0
trror Prokobilitj om i lu|i olTrut ColdlUni
Unrn Flaon Dtut Lead Haunl Ser«n SUndwil 25 (ui/fl2)
(TorM Sunpln)
btinwUn; Gogmrtnc MMH
* ** ArUhmttlc HMD
ZOJOWWMTOlOWiOO
Tnu Homo Coomotric lion Dull Utd Lwdml (u|/IU) on noon
Imr ProtabUJIf oior I lu|< ol Tnio Condiliono
Uiiai findo* Sillo Duit Elk ioooonaint SUndord 260 (uc/(12)
(Tlino SompUo)
- Coonoliic Ibu
* AnUuneUc Ueu
• Uuimuffi
SO 1001SO!OOZ50M03M«04M5M
Tm. Hoi»» C~m*K »«o« »»l Uid loodlDI |ut/H2) on *lado« Ml
[rra Probobllllr onr > bi|o ol Truo Coodilioni
Unn| rmdov Siili Duit l*«d Huord Scroon SUmUrd 125 |ut/lt2}
(Thno Soaplu)
U ,001MZOOZ503003M4004M500
True HOUH Cwnwtric Uiu Dust Le.
-------
trior Pr»e.bujl7 ••«• • «Aif« ol Tm. Condition!
Umil Floon DIM Bit ti Tiinl iUmlml 50 lm/IU)
1.0
Of
0.9
0.7
J 0.5
!»
O.J
u
Ejtim«ton: C«H»trtc Ultn
• *-* Arithmetic feu
taimum
,0 ZO 30 « 50 «0 70 M K 100
Tn» HOUJ. Gwnttiic Ibu Dull Uxl Unim (««/ll2) OD Hoc™
tmr ProUbiMj gm • hn|> gl Tnit C
UBIH noon Duit Ukd JUwrt Screen SUntUrt ZS (u«/IU)
1020904050BOTCM90100
Tnu HOUM CMmithc MMH Duit LNd u.dun (u(/ft2) on n»on
Envr ProlKbmi; onr I lUaje ol True Condition!
Uiirn rmdo* Silli IhjJt Kuk immunt SLindtnl ZSO (uf/H2)
50 «OUOM«BO»»«0«OSOO
Tnil Hon» C«on»lric Hun Hurt Lud U.din (u|/IU) onTinilo. Hill
0»
0.6
0.7
|u
Error Protwbilltr onr a Ruifl ol True Condition!
Uiin| rmdoi Sillj Dull U.d Huud Scm
(fourSunpM
* *-* irlthinoUc Kou
SO 100150Z002S03003M4004MMQ
Tn» Houii Cecmtlric HUD Duft Uttd iMdlOf (m/(t2) on
Figure 1-6. Comparison of Risk Assessment and "Compound" Lead Hazard Screen
Geometric Mean, Arithmetic Mean, and Maximum Value Error Probabilities for
Four Floor and Window Sill Dust Samples Using the Proposed Rule Standards -
Variance Components from the Rhode Island Department of Health Homes.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 I-7
-------
Errai Prob.bilitr tftr • R*o«. ol Tru. Condition!
Uilnt SoU 3Uad*rd. tOOO ppm
(Two round.Ll<,B Soil StmplM)
KM 1000 tBOO 1000 ESOO 3000 3500 4000
Hour* G«om«tr1c IwU SoU LMd Conc.alr.Uon (j>pm) on
bror ProMMlUr «nr • lUap of Tni* Condlttou
Urin| SoU SUndtri. 2000 ppm
[Tw» BoundtrtM 9oU hmpki]
1500 zooo noo
U«u SoU Lt*d CoocwtraUoB (pp
aooo asoo
) on Boiu>d«rtM
Error Pnb*hilitr «*w • *-n«« of Tni*
Uiln| SoU 3Uad*rd. 2000 ppm
(ThTM
SOO 1000 1900 ZOOO tSOO 3000 9900
• (ppm) OB F
Error FroWbUilr *nr • IUa<« ol Tru* CcodiUeni
Una« SoU 9Und*ni. ZOOO ppm
CThrM DoundMiH Soil Sunpto)
} 1000 1900 COOO IBOO 9000
HOUM Cwoutric tUu Soil Uad C*oe.ntr«tion (ppm) on
Imr Prob.bililj «nr • (Unj« ol Tru* Condition!
Utlnf 5oU SUniUrd, ZOOO ppm
(Pour FouBdiUoB B
E»Um*tori: Cooewtrie UM*
) 1000 1900 MOO 2500 3000 3600 4000
HOUM Coomotrle MMUI SoU Load CMtowlnUM (ppm] OB
ir Protabilily or«r • R*nf« of Tru* CondiUoni
Uilni SoU 5Und»rt, 2000 ppm
(TOUT BoUDdirtM SOU S
SOD tOOO 1500 ZOOO KOO 9000 9
HOUM C«om*tric MHB Sail U*d Cooc.nlr.Uon (ppm) M BauoduiM
Figure 1-7. Comparison of Risk Assessment Geometric Mean, Arithmetic Mean, and
Maximum Value Error Probabilities for Two, Three, and Four Soil Samples
Collected from the Foundation of the Home and Boundary of the Property
Using the Proposed Rule Standards - Variance Components from the CAP
Study Data.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 I-8
-------
Error Probability ov.r » Rang* of Tr-u* Co
(Two Foundation Soil Sampl«»)
BOO 1ODO 1BOO EOOO
BOO 3000 3000 4000
Error Probability ov.r * Rang* of Tru« Coi
U.ine Soil Standard, EOOO ppm
(Thr»« Foundation Soil S«mpl*«)
!000 1BOO ZOOO ZSOO 3OOO 3SOO 4OOO
• Probability ov»r a Rang* °f Tru» Co
U»lna Soil Staiidoird, EOOO ppm
(Four Foundation Soil Sampl««)
500 10'00 1000 ZOOO 2600 3OOO 3BOO *OOO
Figure 1-8. Comparison of Risk Assessment Geometric Mean, Arithmetic Mean, and
Maximum Value Error Probabilities for Two, Three, and Four Soil Samples
Collected from Side of the House/Foundation for Homes Using the Proposed
Rule Standards - Variance Components from the Rhode Island Department of
Health Study Data.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 I-9
-------
Table 1-1. Comparison of Risk Assessment Error Probabilities for Each Statistic Over A
Range of Assumed "True" House Lead Levels for Two. Three, and Four Floor
Dust Samples Using the Proposed Rule Standards1 - Variance Components
from the Rochester Lead-in-Dust Study Data.
'Compound
Lead Hazard
Screen
Risk
Assessment
Number
of
Samples
2
3
4
2
3
4
Assumed
•True-
House Floor
Dust Lead
Loading
(//a/ft1)
25
50
100
25
50
100
25
50
100
25
50
100
25
50
100
25
50
100
Error Probability of the Statistic
Type 1 Error
Arithmetic
Mean
0.140
0.530
.
0.150
0.623
.
0.150
0.712
.
0.237
0.598
.
0.231
0.660
,
0.206
0.730
Geometric
Mean
0.072
0.428
.
0.048
0.452
.
0.033
0.467
.
0.144
0.500
.
0.096
0.500
.
0.066
0.500
Maximum
Value
0.300
0.712
.
0.469
0.865
.
0.601
0.935
.
0.401
0.750
.
0.536
0.875
.
0.641
0.938
Arithmetic
Mean
.
0.465
0.120
.
0.355
0.059
.
0.339
0.025
.
0.404
0.113
.
0.326
0.056
.
0.316
0.024
Type II Error
Geometric
Mean
.
0.572
0.158
.
0.548
0.100
.
0.533
0.067
•
0.500
0.144
.
0.500
0.096
.
0.500
0.066
Maximum
Value
•
0.288
0.055
•
0.135
0.012
•
0.065
0.003
•
0.250
0.051
•
0.125
0.012
•
0.063
0.003
1 The floor dust wipe standard at which a home fails the assessment was assumed to be 50 pg/ft2 for the
risk assessment and 25 jsg/ft2 for the lead hazard screen.
Draft Report - Do Not Quote, Cite. Copy or Distribute
February 15, 1999 1-10
-------
Table 1-2. Comparison of Risk Assessment Error Probabilities for Each Statistic Over A
Range of Assumed "True" House Lead Levels for Two. Three, and Four
Window Sill Samples Using the Proposed Rule Standards1 - Variance
Components from the Rochester Lead-in-Dust Study Data.
Assessment
"Compound"
Lead Hazard
Screen
Risk
Assessment
Number of
Samples
2
3
4
2
3
4
Assumed
•True"
House
Window
Sill Dust
Lead
Loading
Oig/ft')
125
250
500
125
250
500
125
250
500
125
250
500
125
250
500
125
250
500
Error Probability of the Statistic
Type 1 Error
Arithmetic
Mean
0.182
0.530
.
0.214
0.629
.
0.255
0.736
.
0.304
0.610
.
0.316
0.681
.
0.335
0.763
Geometric
Mean
0.098
0.402
.
0.073
0.427
.
0.056
0.444
.
0.195
0.500
.
0.147
0.500
.
0.112
0.500
Maximum
Value
0.352
0.695
.
0.537
0.857
.
0.674
0.932
.
0.470
0.750
.
0.614
0.875
.
0.719
0.938
Type II Error
Arithmetic
Mean
•
0.475
0.157
0.350
0.086
.
0.319
0.039
.
0.392
0.131
.
0.303
0.076
.
0.288
0.036
Geometric
Mean
•
0.598
0.230
•
0.573
0.162
•
0.556
0.119
.
0.500
0.195
•
0.500
0.147
.
0.500
0.112
Maximum
Value
•
0.305
0.086
•
0.143
0.021
0.068
0.006
•
0.250
0.074
•
0.125
0.020
•
0.063
0.005
1 The window sill dust wipe standard at which a home fails the assessment was assumed to be 250 pg/ft1.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 1-11
-------
Table 1-3. Comparison of Risk Assessment Error Probabilities for Each Statistic Over A
Range of Assumed "True" House Lead Levels for Two, Three, and Four Floor
Samples Using the Proposed Rule Standards1 - Variance Components from the
Rhode Island Department of Health Data.
=====
Assessment
=====
'Compound*
Lead Hazard
Screen
Risk
Assessment
===
Number
of
Samples
===
2
3
4
2
3
4
=====
Assumed
•True"
House Floor
Dust Lead
Loading
U/g/ft')
=====
25
50
100
25
50
100
25
50
100
25
50
100
25
50
100
25
50
100
Error Probability of the Statistic
Type 1 Error
Arithmetic
Mean
=====
0.120
0.538
.
0.122
0.621
.
0.124
0.703
0.207
0.593
0.192
0.652
,
0.172
0.717
Geometric
Mean
0.061
0.439
.
0.038
0.462
.
0.025
0.475
.
0.122
0.500
.
0.077
0.500
.
0.050
0.500
•
Maximum
Value
0.276
0.718
.
0.435
0.867
.
0.563
0.936
.
0.368
0.750
.
0.498
0.875
.
0.601
0.938
Type II Error
Arithmetic
Mean
.
0.466
0.097
0.358
0.048
•
0.345
0.021
•
0.411
0.092
.
0.334
0.048
•
0.329
0.020
Geometric
Mean
•
0.561
0.131
•
0.538
0.079
•
0.525
0.050
•
0.500
0.122
•
0.500
0.077
•
0.500
0.050
Maximum
Value
==
0.282
0.044
•
0.133
0.009
•
0.064
0.002
•
0.250
0.042
•
0.125
0.009
•
0.063
0.002
1 The floor dust wipe standard at which a home fails the assessment was assumed to be 50 pg/ft2 for the
risk assessment and 25 pg/ft2 for the lead hazard screen.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 1-12
-------
Table 1-4. Comparison of Risk Assessment Error Probabilities for Each Statistic Over A
Range of Assumed "True" House Lead Levels for Two. Three, and Four
Window Sill Samples Using the Proposed Rule Standards1 - Variance
Components from the Rhode Island Department of Health Data.
Assessment
'Compound*
Lead Hazard
Screen
Risk
Assessment
Number
of
Samples
2
3
4
2
3
4
Assumed
House
Window Sill
Dust Lead
Loading
foig/ft2)
125
250
500
125
250
500
125
250
500
125
250
500
125
250
500
125
250
500
Error Probability of the Statistic
Type 1 Error
Arithmetic
Mean
0.205
0.526
0.257
0.638
.
0.311
0.745
•
0.337
0.619
.
0.375
0.697
.
0.403
0.778
•
Geometric
Mean
0.110
0.390
.
0.086
0.414
.
0.069
0.431
•
0.220
0.500
.
0.173
0.500
.
0.138
0.500
•
Maximum
Value
0.375
0.686
.
0.566
0.853
.
0.703
0.931
•
0.500
0.750
.
0.646
0.875
.
0.750
0.938
•
Type II Error
Arithmetic
Mean
•
0.481
0.185
.
0.345
0.097
.
0.317
0.047
.
0.386
0.151
.
0.289
0.084
.
0.277
0.043
Geometric
Mean
•
0.610
0.268
•
0.586
0.197
•
0.569
0.150
•
0.500
0.220
•
0.500
0.173
•
0.500
0.138
Maximum
Value
•
0.314
0.103
•
0.147
0.028
•
0.069
0.008
•
0.250
0.086
•
0.125
0.025
•
0.063
0.007
The window sill dust wipe standard at which a home fails the assessment was assumed to be 250 //g/ft2.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 1-13
-------
Table 1-5. Comparison of Error Probabilities for Each Statistic Over a Range of Assumed
"True" House Lead Levels for Two. Three, and Four Boundary and Foundation
Soil Samples Using the Proposed Rule Standards1 - Variance Components from
the CAP Study Data.
Location
^=^^^^=
Boundary
of Property
Foundation
Number
of
Samples
2
3
4
2
3
4
Assumed
"True" House
Soil Lead
Concentration
(ppm)
1,000
2,000
3,000
1,000
2,000
3,000
1,000
2,000
3,000
1,000
2,000
3,000
1,000
2,000
3,000
1,000
2,000
3.000
Error Probability of the Statistic
Type 1 Error
Arithmetic
Mean
^^=^^^^=
0.046
0.563
t
0.022
0.615
0.011
0.654
m
0.173
0.587
0.155
0.645
0.132
0.709
Geometric
Mean
0.022
0.500
,
0.007
0.500
.
0.002
0.500
.
0.103
0.500
0.061
0.500
.
0.037
0.500
•
Maximum
Value
0.150
0.750
.
0.217
0.875
.
0.278
0.938
.
0.337
0.750
.
0.460
0.875
.
0.561
0.938
Type II Error
Arithmetic
Mean
.
0.432
0.094
.
0.399
0.057
.
0.396
0.026
.
0.416
0.187
.
0.346
0.128
.
0.342
0.061
Geometric
Mean
•
0.500
0.120
.
0.500
0.075
.
0.500
0.049
.
0.500
0.230
.
0.500
0.183
.
0.500
0.148
Maximum
Value
=^^^=
0.250
0.041
•
0.125
0.008
•
0.063
0.002
•
0.250
0.090
.
0.125
0.027
•
0.063
0.008
The soil standard at which a home fails the assessment was assumed to be 2,000 ppm.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 1-14
-------
Table 1-6. Comparison of Error Probabilities for Each Statistic Over a Range of Assumed
"True" House Lead Levels for Two. Three, and Four Side of House/Foundation
Soil Samples Using the Proposed Rule Standards1 - Variance Components from
the Rhode Island Department of Health Data.
Location
Side of
House/
Foundation
Number
of
Samples
2
3
4
Assumed
"True" House
Soil Lead
Concentration
(ppm)
1.000
2,000
3.000
1.000
2.000
3.000
1.000
2.000
3 000
Error Probability of the Statistic
Type 1 Error
Arithmetic
Mean
0.262
0.605
.
0.271
0.668
.
0.265
0.745
Geometric
Mean
0.168
0.500
0.119
0.500
.
0.086
0.500
Maximum
Value
0.434
0.750
.
0.574
0.875
.
0.680
0.938
Type II Error
Arithmetic
Mean
•
0.398
0.229
.
0.313
0.156
.
0.304
0.082
Geometric
Mean
•
0.500
0.286
•
0.500
0.245
.
0.500
0.213
Maximum
Value
•
0.250
0.119
•
0.125
0.041
•
0.063
0.014
1 The soil standard at which a home fails the' assessment was assumed to be 2,000 ppm.
Draft Report - Do Not Quote. Cite, Copy or Distribute
February 15, 1999 1-15
-------
This page intentionally blank.
-------
APPENDIX J
Summary of the Pathways Analysis
for the Rochester Lead-in-Dust Study Data
Draft Report - Do Not Quote, Cite, Copy or Distribute February 15, 1999 J-1
-------
o
S
3)
-------
o
3
s
I
O
o
q
3
o
o
q
I
5=
Table J-2. Structural Equation Modeling Results for the Rochester Study Data.
Variables
^*s. Independent
Blood
Play Area Floor
Bedroom Floor
Kitchen Floor
Play Area Window
Sill
Bedroom Window
Parameter Estimates (t-value)
Play Area -
0.1611"
(1.98)
-0.0050
(-0.01)
-3.9562
(-0.45)
Bedroom
-0.0577
(-0.80)
-0.3090
(-0.52)
4.2132
(0.55)
Kitchen
Floor
0.0225
(0.28)
0.9845
(1.78)
-1.6241
(-1.69)
Interior
Entryway
Floor
0.1038
(1.52)
-0.1338
(-0.67)
1.2979'
(2.04)
0.2159
(0.33)
Play Area
Window Sill
0.0470
(0.92)
0.2131
(1.63)
Bedroom
Window Sill
-0.0052
(-0.11)
0.5774*
(1.98)
Play Area
Window
Well
0.0406
(1.23)
-0.0308
(-0.51)
0.3548*
(6.53)
Bedroom
Window
Well
0.0043
(0.14)
-0.0269
(-0.29)
0.3627"
(6.14)
R1
0.24
0.01
0.00
0.00
0.34
0.32
Note: 1. The first number is the estimated parameter and the second number is the corresponding t-value.
2. Bolded and a • indicates parameter estimate is statistically significant at the 0.05 level. T-values > 1.95 or < -1.95 indicate
significance at the 0.05 level.
3. The structural equation models were run using natural logarithm transformed dust-lead loadings and blood-lead concentrations.
31
IT
B>
CD
CO
(O
CO
-------
This page intentionally blank.
-------
APPENDIX K
Documents Used In Obtaining
Health Department Data
Draft Report - Do Not Quote, Cite, Copy or Distribute February 15, 1999 K-1
-------
Example K-1. The Data Set Assessment Form For the First Contact with Health
Departments
Date of Assessment:
1. Agency: Pennsylvania Department of Health
Name: Helen Shuman
City, State: . .—
Phone:
2. Name of Data Set:
3. Population Size:
4. Program funded by:
5. Data Available? YES NO
6. Age of children in the program:
7. Data collected:
a. Child blood-lead concentrations? YES NO
Frequency of the blood-lead assessment:
Every month
Every other month
Every three months
Every six months
Other (list frequency):
b. Environmental samples collected? YES NO
Dust? YES NO
Soil? YES NO
Paint? YES NO
Other? YES NO
Please specify:
Draft Report - Do Not Quote. Cite, Copy or Distribute February 15, 1999 K-2
-------
Example K-1. The Data Set Assessment Form For the First Contact with Health
Departments (Continued).
Data Set Assessment - Part A Page - 2
Frequency of environmental sampling?
c. Assessment of the exposure in home, other sources of lead exposure outside of the
home, socioeconomic factors, etc. YES NO
By questionnaire? YES NO
By interview at home? YES NO
By telephone interview? YES NO
Other? YES NO
Please specify: .
8. What is the form of the data?
Hardcopy? YES NO
Disk? YES NO
Draft Report - Do Not Quote, Cite. Copy or Distribute February 15, 1999 K-3
-------
Example K-2. Letter and Data Information Sheet Sent to Health Departments for
Formal Request of Data.
May 9,1997
{Person Contacted}
{Department}
{Agency}
{Street Address}
{City, State Zip}
Dear {Person Contacted):
This letter is a follow-up to a conversation you had with {Interviewer} of Battelle
Memorial Institute and serves as a formal request for obtaining data from your agency.
The Technical Branch of the U.S. Environmental Protection Agency is interested in
evaluating different sampling protocols allowable under the Section 402 risk assessment protocol
(40 CFR Part 745) to determine if certain protocols are more protective of public health than
others. EPA has contracted with Battelle Memorial Institute of Columbus, Ohio to conduct this
study. In order to evaluate the protocols, EPA needs pre-intervention blood lead and pre-
intervention environmental samples of lead in dust, soil, and paint. Your data will be used to
assess how well dust, soil, or paint samples collected under a given sampling protocol can
identify a health hazard as measured by the blood-lead sample. This will be done on an
aggregate level such that individual results will NOT be reported.
In an earlier conversation, it was indicated that your agency has collected and maintained
data that may be extremely useful for this project. We are very interested in obtaining your data.
The attached sheet specifies the type of data, fields, and format (hardcopy or diskette) we are
requesting. We understand that confidentiality is of great importance and will be provided. We
do need to be able to link the environmental samples with the blood samples. Once that data is
linked, we only require a unique identifier for each household, such as "House 1". Being able to
uniquely link the blood samples with the environmental samples is very important, but we do not
need to know the address of the house, the name of the child, or any other information from
which the name or address could be deduced.
Draft Report - Do Not Quote, Cite, Copy or Distribute February 15. 1999 K-4
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{Person Contacted}
{Department}
{Agency}
Page 2
Results of the data analysis will be used to provide additional information to help risk
assessors evaluate potential lead-based paint hazards in a residential setting. You will receive a
copy of the final report, and can be included in the review process of draft interim reports if you
so choose.
We appreciate your interest in helping us conduct this study. Please send your data to
Virginia Sublet/Pam Hartford, Battelle Memorial Institute, 505 King Avenue, Columbus, Ohio,
43201.
If you have any questions regarding the requested data, the intent of the study, or the use
of your data please contact Susan Dillman of my staff at (202) 260-5375, Virginia Sublet of
Battelle at (614) 424-5406, or Pam Hartford of Battelle at (614) 424-5448.
Sincerely,
Brion Cook, Chief
Technical Branch
Enclosures
cc: S. Dillman-U.S. EPA
V. Sublet-Battelle
P. Hartford-Battelle
Draft Report - Do Not Quote, Cite, Copy or Distribute February 15, 1999 K-5
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DATA REQUEST AND INFORMATION SHEET
The requested data should consist of samples that were collected prior to any
intervention activities at the home or with the child. Also, the sample collection date for the
environmental samples should be fairly close to the sample collection date for the related blood
sample.
The tables listed below should be used as a guide for the exact information being
requested. The first column of the tables below list the variable requested and provides a brief
explanation of the variable. The second column provides an order of importance on variables
requested. The last column requests the name of the variable in the data set, if the variable is in
the data set. If the variable is not available, then indicate with a 'NA'. If a short answer provides
the requested information, please list the information in this column instead of a variable name,
e.g. the blood sampling technique may require only an answer of venous puncture since all
children had blood drawn using that technique.
Pre-lntervention Child Blood Sampling Variables Requested
Variable RGQU6StGd
Blood sampling date
Blood-lead concentration
Age of child when sampling occurred
(Preferably between 6 months and 6 years of age}
Unique identifier for the home the child resided in at time of
sampling
{If there are multiple children within a home the identifier
would be the same for all children}
Blood sampling technique
Importance of
Requested
Information
Very Important
Very Important
Very Important
Very Important
Moderately Important
Variable Name in
the Data Set*
If a short answer provides the requested information, please list the information in this column instead of a
variable name, e.g. The blood sampling technique may require only an answer of venous puncture since all
children had blood drawn using that technique.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15. 1999 K-6
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DATA REQUEST AND INFORMATION SHEET
Pre-lntervention Environmental Sampling Variables Requested
Unique identifier of home that can be matched to the blood
Importance of
Requested Information
Very Important
Date of dust sampling
Units of reported dust lead level {i.e., tig/ft1, ug/g, etc.}
Sampling component {i.e., carpeted floors, uncarpeted
Limit of detection for the lab
Very Important
Very Important
Very Important
Very Important
Very Important
Very Important
Very Important
Moderately Important
Moderately Important
Sample type (i.e.. composite or individual samples)
Ground covering (i.e., bare, grassy, % of area covered.
Very Important
Very Important
Very Important
Very Important
Very Important
Moderately Important
Moderately Important
Moderately Important
Pre-lntervention Paint Samples
Units of reported paint lead levels {ppm, %, mg/cm'.
Sampling technique {i.e., XRF, bulk scraping, etc.}
Sampling location (i.e., interior or exterior, bedroom.
Sampling component {i.e., wall, window sill, window
Condition of the paint {i.e., poor, % deteriorated, etc.}
Very Important
Very Important
Very Important
Very Important
Very Important
Very Important
Very Important
Very Important
the Data Set*
If a short answer provides the requested information, please list the information in this column instead of a
variable name, e.g. The blood sampling technique 'may require only an answer of venous puncture since all
children had blood drawn using that technique.
Draft Report - Do Not Quote, Cite, Copy or Distribute
February 15, 1999 K-7
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DATA REQUEST AND INFORMATION SHEET
Please indicate the format of your data: D Hardcopy D Diskette
If diskette, what software was used?
Please indicate if any of your data collection efforts were funded by the HUD Lead-Based Paint
Hazard Control Grant Program. D Yes D No
If you are willing to help us in this project, please return a copy of this sheet with your
data to the following address:
Virginia Sublet / Pam Hartford
Battelle Memorial Institute
505 King Avenue
Columbus, OH 43201
Or, if you have additional questions, please contact:
Virginia Sublet (614) 424-5406
Pam Hartford (614) 424-5448
Draft Report - Do Not Quote. Cite, Copy or Distribute February 15. 1999 K-8
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Table K-1. Summary of the Health Department Data.
Agency
Rhode Island
Department of
Health
Pinellas County
Health
Department
Nebraska Health
and Human
Services System
Vermont
Department of
Health
CHy, State
Providence. Rl
St. Petersburg,
FL
Lincoln. NE
Burlington. VT
Data Collected
Blood
Dust
Soil
Paint
Water
Blood
Dust
Soil
Paint
Blood
Dust
Soil
Paint
Blood
Dust
Soil
Water
Paint
Description
Venous and Fingerstick
Wipe and Vacuum
Side and Debris
Paint Chip
Flush
Venous and Fingerstick
Wipe
Surface Scraping
XRF
Venous and Fingerstick
Wipe
Surface Scraping
XRF and bulk sampling
Venous
NA
NA
NA
XRF
Time Frame
1/1/1995-12/1/1996
1/1/1995- 12/1/1996
1/1/1995-12/1/1996
1/1/1995- 12/1/1996
1/1/1995-12/1/1996
1994- 1997
1994- 1997
1994-1997
1994- 1997
2/5/1996-6/18/1997
7/11/1996-
7/22/1997
7/19/1996-
7/22/1997
3/14/1997-
7/22/1997
1995-1996
NA
NA
NA
NA
it of Observations
(# Homes)
400 (285)
522(129) 2
766 (264)
4265 (325)
272 (265) 3
49 (49)
10(7)
15(15)
38 (38)
15(15)
38(11)
26(10)
838(11)
110(110)
NA
NA
NA
NA(110)
Comments
Good distribution of
environmental and blood
sampling across the homes.
Sparse environmental sampling
across the homes.
Sparse environmental sampling
across the homes.
Quite a bit of paint XRF data
with excellent location specific
information. Very little dust.
soil, and water information.
§•
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Table K-1. Summary of the Health Department Data (Continued).
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Ohio Department
of Health
Missouri
Department of
Health
Cftv Statfi
Columbus. OH
Jefferson City,
MO
Data Collected
Blood
Dust
Soil
Paint
Other
Blood
Dust
Soil
Paint
Water
Description
Venous
Wipe
Composite
Mostly Drip line
XRF
NA
NA
NA
NA
XRF and Paint
NA
Time Frame
9/7/1993-
4/21/1997
8/14/1996-
5/5/1997
10/22/1993-
3/18/1997
10/12/1993-
11/12/1996
NA
NA
NA
NA
NA
NA
# of Observations
(# Homes)
48 (21 11
98 (23)
32 (20)
1842(32)
1 (D
76,745 (30.586)
912(884)
912(884)
912(884)
912(884)
Comments
XRF readings but sampling
dates are missing. Also sparse
environmental sampling.
Data is from a STELLAR data
base which retains only the
maximum value from the
environmental sampling. Values
from all the sampling were not
available.
Notes: ' This does not contain 16 observations with age missing and 9 observations with 'Unknown' or missing sampling method.
2 There are 454 observations (109 homes) for WIPE only Dust data.
3 This does not contain 66 observations with water collection method other than 'Flush'.
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APPENDIX L
Sampling Distributions of the Statistics and
Error Probability Calculations
Draft Report - Do Not Quote, Cite, Copy or Distribute February 15, 1999 L-1
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Appendix L
Sampling Distributions of the Statistics and
Error Probability Calculations
The observed natural logarithmically transformed lead level, log(Yik), was assumed to
follow a normal distribution with mean u, and variance o2, i.e.,
log(Yik) iid -Normal^,, o,2), k=l,2,..., n
where
Yk k* observed lead level in the home for component/media i
i ' floor dust, window sill dust, window well dust, foundation soil, boundaries soil,
or paint.
An assumption was that no room was more indicative of the risk of lead exposure to
children than any other room within the house.
To compare the effectiveness of the estimators in providing an accurate assessment of the
true house lead levels, a hypothesis test was constructed:
H0: u,
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Yy observed lead level in the home for component/media i and estimator./
Sj standard for component/media /
Hi true average log lead level within home for each component/media i
i floor dust, window sill dust, window well dust, soil, and paint,
j geometric mean, arithmetic mean, and maximum value.
Sampling Distribution of the Geometric Mean
Let Gj = geometric mean of YIk component/media / with k rooms sampled (k locations, in the
case of soil data), k = 1, 2 ..... n.
n
n "| ZlogYik
Then lo iY* =—n
\k=i )
since log(Yik) iid ~Normal(u,, o,2), k=l,2 ..... n.
Therefore, under the above hypotheses,
(1) given that H0: Uj < log Sj is true,
P(Type I Error) = P(G, * Sj)
log(S,))
n)"2 * [log(S,)
since log(Gj) ~Normal(Ui, of2/n)
where Z-N(O.l).
(2) given that H,: U; * log S, is true,
P (Type H Error) = P(G, < S,)
= P(log(G,) < logCSi))
= PttlogtGi)- (UiMof/n)"2 <
= P(Z < [logCSi) - (u^/COiVn),
since log(G,) -Normal(Ui, OjVn)
where Z -N(0, 1).
Draft Report - Do Not Quote, Cite, Copy or Distribute February 1 5, 1 999 L-3
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Sampling Distribution of the Arithmetic Mean
There is no simple form of the sampling distribution of the arithmetic mean. Therefore,
the error probabilities were estimated via simulation based on the empirical distribution of the
arithmetic mean.
Sampling Distribution of the Maximum Value
The sampling distribution of the maximum value is derived below.
Let Mj denote the maximum value of n measurements, Y^, j = 1 ..... n on the same
component/media at a single house.
Then,
(1) Given that u, < log S, is true,
P(Type I Error) = P(M; * S;)
= 1-P(M,
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