United States
Environmental Protection
Agency
Office of
Pollution Prevention and Toxics
7401
EPA747-R-99-003
September. 1999
Evaluation of Section 402
Risk Analysis Protocols
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EPA 747-R-99-003
September, 1999
EVALUATION OF SECTION 402
RISK ANALYSIS PROTOCOLS
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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DISCLAIMER
The material in this document has been subject to Agency technical and policy review.
Mention of trade names, products, or services does not convey, and should not be interpreted as
conveying, official EPA approval, endorsement, or recommendation.
FURTHER INFORMATION
Additional copies of this report can be obtained by calling the National Lead Information
Center at 1-800-424-LEAD. Information about other technical reports on lead can be found
through the internet at the address: http://www.epa/gov/lead.
This report is copies on recycled paper.
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AUTHORS AND CONTRIBUTORS
The study that led to this report was funded and managed by the U.S. Environmental
Protection Agency. The study was conducted by Battelle Memorial Institute. Each
organization's responsibilities are listed below.
Battelle Memorial Institute (Battelle)
Battelle was responsible for the data management, the development of the statistical
models, the statistical analysis, and the writing of this report.
U.S. Environmental Protection Agency (EPA)
The U.S. Environmental Protection Agency funded the task, managed the task, reviewed
task documents, and managed peer review of this report. The EPA Work Assignment Manager
was Benjamin Lim. The Project Officer was Sineta Wooten.
HI
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TABLE OF CONTENTS
EXECUTIVE SUMMARY xi
1.0 INTRODUCTION 1
1.1 OBJECTIVES 4
1.2 STRUCTURE OF THE REPORT 5
1.3 PEER REVIEW 6
2.0 CONCLUSIONS 10
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 10
2.1.1 Risk Assessor Costs 10
2.1.2 Performance Characteristic Analysis 11
2.2 OBJECTIVE 2: ABILITY OF ESTIMATORS AND SAMPLING PROTOCOLS TO
DETERMINETRUE" AVERAGE LEAD LEVELS 13
2.3 OBJECTIVE 3: SAMPLING LOCATIONS RISK ASSESSORS MAY WANT TO
TARGET TO EVALUATE POTENTIAL LEAD HAZARDS 14
3.0 QUALITY ASSURANCE 16
4.0 DATA SOURCES 18
4.1 ROCHESTER LEAD-IN-DUST STUDY 19
4.2 HEALTH DEPARTMENT DATA SOURCES 21
4.3 RISK ASSESSOR COST INFORMATION 24
5.0 STATISTICAL METHODS 26
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 27
5.1.1 Risk Assessor Cost Information 27
5.1.2 Performance Characteristics 30
5.2 OBJECTIVE 2: ABILITY OF ESTIMATORS AND SAMPLING PROTOCOLS TO
DETERMINE TRUE AVERAGE LEAD LEVELS 38
5.2.1 Key Analysis Assumptions 38
5.2.2 Error Probability Calculations 39
5.2.3 Within-House Variation Calculations 41
5.2.4 Data Used to Characterize Within-House Variation 41
5.2.5 Error Probability Calculations Associated with "Simple* and
"Compound" Lead Hazard Screens 43
5.3 OBJECTIVE 3: SAMPLING LOCATIONS RISK ASSESSORS MAY WANT TO
TARGET TO EVALUATE POTENTIAL LEAD HAZARDS 45
5.3.1 Data Used in the Analysis 45
5.3.2 Correlation Analysis 46
5.3.3 Pathways Analysis 47
6.0 RESULTS 51
IV
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TABLE OF CONTENTS
(Continued)
Page
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 51
6.1.1 Risk Assessor Cost Summaries 51
6.1.2 Performance Characteristic Analysis Results 63
6.2 OBJECTIVE 2: ABILITY OF ESTIMATORS AND SAMPLING PROTOCOLS TO
DETERMINE TRUE AVERAGE LEAD LEVELS 84
6.2.1 Within-House Variance Components 84
6.2.2 Effect of the Use of the Geometric Mean, Arithmetic Mean,
and Maximum Value on the Error Probabilities 85
6.2.3 Effect of the Number of Media Samples Collected 99
6.2.4 Effect of the Interim Guidance and Proposed Rule Standards on the
Error Probabilities 100
6.3 OBJECTIVE 3: SAMPLING LOCATIONS RISK ASSESSORS MAY WANT TO
TARGET TO EVALUATE POTENTIAL LEAD HAZARDS 103
6.3.1 Correlation Analysis Results 103
6.3.2 Pathways Model Results 104
7.0 DISCUSSION 106
7.1 PERFORMANCE CHARACTERISTICS AND ERROR PROBABILITIES 106
7.2 PATHWAYS ANALYSIS 107
7.3. PROPOSED RULE COMPARED TO THE INTERIM GUIDANCE 108
8.0
REFERENCES 109
APPENDIX A
APPENDIX B
APPENDIX C
APPENDIX D
APPENDIX E
APPENDIX F
APPENDIX G
APPENDIX H
APPENDIX I
APPENDIX J
APPENDIX K
APPENDIX L
LIST OF APPENDICES
Section 402 Guidance for Risk Analysis Procedures A-1
Summary of the Activities of a Risk Assessor as Specified in the Risk
Assessor Curriculum B-1
Risk Assessor Cost Questionnaire C-1
Choices for a Risk Assessor D-1
Blood and Environmental Sampling Standards , E-1
Data Set Criteria F-1
Summary Tables and Figures G-1
Summary Error Probability Tables and Graphs for the Interim
Guidance Standards H-1
Summary Error Probability Tables and Graphs for the Proposed Rule
Standards 1-1
Summary of the Pathways Analysis for the Rochester Lead-in-Dust
Study Data J-1
Documents Used In Obtaining Health Department Data K-1
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 xiii
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 12
Table 4-1. Distribution of the Year Homes were Built and Children's Ages for the
Rochester Lead-in-Dust Study 20
Table 4-2. Distribution of Children's Ages in the Rhode Island Department of Health
Data 23
Table 5-1. Definitions of Performance Characteristics 30
Table 5-2. Sampling Protocol Group A: Assessing the Impact of Dust Sampling from
Specific Rooms Included in a Risk Assessment 36
Table 5-3. Sampling Protocol Group B: Assessing the Impact of Using Different
Summary Measures to Characterize Dust Samples for a Risk Assessment 36
Table 5-4. Sampling Protocol Group C: Assessing the Outcome of a Lead Hazard
Screen Versus a Risk Assessment 37
Table 5-5. Summary of the Statistics Calculated to Characterize the Protocols 37
Table 5-6. Data Used for Calculating the Within-House Components of Variation 42
Table 5-7. Rooms and Types of Components Sampled in the Rochester Study 46
Table 6-1. Average Total Cost of a Risk Assessment, Lead Hazard Screen,
Inspection, and Risk Assessment/Inspection With and Without Extremely
High Costs 53
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 59
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 60
Table 6-4. Average Number of Environmental Samples Collected for a Risk
Assessment, Lead Hazard Screen, Inspection, and Risk
Assessment/Inspection, Over All Media, By Contractor 62
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 63
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) 65
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 25% Deteriorated Paint) 66
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) 67
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TABLE OF CONTENTS
(Continued)
Page
Table 6-9. Number of Additional Homes in Which Lead-Based Paint Hazards Were
Found When the Entry way and Kitchen Were Sampled 68
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) 70
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) 71
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) 72
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 26% Deteriorated
Paint) 74
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) 75
Table 6-15. Summary of the Assessment of Lowered Soil and Dust Standards
Associated with the Proposed Rule Relative to the Interim Guidance 78
Table 6-16. Summary of the Assessment of the Exclusion of Window Well Sampling
Under the Proposed Rule Relative to the Interim Guidance 79
Table 6-17. Summary of the Comparison of the Interim Guidance Results and
Proposed Rule Results for a Full Risk Assessment 82
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 83
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 83
Table 6-20. Estimated Within-House Components of Variation (Log-Transformed) for
Each Data Source, Medium, and Component 85
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 91
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 92
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TABLE OF CONTENTS
(Continued)
Page
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 93
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 94
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 98
Table 6-26. Summary of the Type I (False Positive) 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 100
Table 6-27. Summary of Type I (False Positive) 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 101
Table 6-28. Summary of Type II (False Negative) 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 102
Table 7-1. Probabilities Calculated for the Performance Characteristic and Error
Probability Analysis 106
LIST OF FIGURES
Figure 5-1. Example of an Ideal Situation When 100% is Achieved For All Four
Performance Characteristics 31
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% 32
Figure 5-3. Pathways of Lead Exposure Investigated Using the Rochester Study
Data 47
Figure 6-1. Total Costs for a Risk Assessment, inspection, Lead Hazard Screen,
and a Risk Assessment/Inspection 52
Figure 6-2. Estimated Costs ($) of the Visual Assessment, Typical Environmental
Sampling, and the Risk Assessment Report for a Risk Assessment 55
Figure 6-3. Estimated Costs ($) of the Visual Assessment, Typical Environmental
Sampling, and the Lead Hazard Screen Report for a Lead Hazard
Screen 56
VIII
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TABLE OF CONTENTS
(Continued)
Page
Figure 6-4. Estimated Costs ($} of the Visual Assessment, Typical Environmental
Sampling, and the Inspection Report for an Inspection 57
Figure 6-5. Estimated Costs ($) of the Visual Assessment, Typical Environmental
Sampling, and the Risk Assessment/Inspection Report for a Risk
Assessment/Inspection 58
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 87
Figure 6-7. Comparison of Risk Assessment Geometric Mean, Arithmetic Mean,
and Maximum Value Error Probabilities for Two, Three, and Four Soil
Samples using the Interim Guidance Standards - Variance Components
from the Foundation of the Home and Boundary of the Property in the
CAP Study Data 88
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 89
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 90
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 97
Figure 6-11. Statistically Significant Pathways of Lead Exposure Using the
Rochester Study Data 105
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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, the U.S. Environmental Protection Agency (EPA) published a final rule for Section
402 of the Toxic Substances Control Act (TSCA) [4], in August 1996, which detailed the
requirements for 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, in other areas the certified individual has the freedom to use personal judgement to
specify the extent of sampling during a risk assessment, including the 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 choices
allowed by the Section 402 regulations are made. Specifically, the choices assessed were the
number of rooms in which dust samples are collected and specific rooms in which dust is
sampled. In addition, the method used 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. The task had three specific objectives:
1. Characterize the way different sampling protocols affect a) the probability of
correctly concluding that an environmental lead hazard exists (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). 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 risk assessors may want to target in order to assure
that they are best evaluating the potential lead hazard to a child (pathways analvsisX
Objective 1 was fulfilled using two sets of information. The first set was the risk
assessment cost information collected from nine risk assessors in nine 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 that lead-based paint hazards have been found in the
home given that there is a child with an elevated blood-lead concentration in the
home
b) Specificity is the probability that no lead-based paint hazards have been found in the
home given that there is a child with a low blood-lead concentration in the home
c) PPV is the probability that the child in the home has an elevated blood-lead
concentration given that lead-based paint hazards have been found in the home
d) NPV is the probability that the child in the home has a low blood-lead concentration
given that no lead-based paint hazards have been found in the home.
Objective 2 was fulfilled using two types of error probabilities: Type I (false positive)
error and Type II (false negative) error. Each is briefly defined as follows:
a) A Type I (false positive) error is the probability of a risk assessment concluding that a
home has lead-based paint hazards when the home does not.
b) A Type II (false negative) error is the probability of a risk assessment concluding that
a home has no lead-based paint hazards when the home does in fact have lead-based
paint hazards.
Finally, Objective 3 was fulfilled 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 performance characteristics and error
probabilities. At the time of this report, the guidance for the Section 402 activities was the
Section 403 Interim Guidance and the HUD Guidelines. When the Section 403 Proposed Rule
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becomes final, the guidance in the Proposed Rule will supersede the Section 403 Interim
Guidance. Therefore, the analyses assessed the impact that the standards in the Proposed Rule
may have on the outcome of risk assessments, compared to the outcomes observed under the
Interim Guidance standards.
Table ES-1. Environmental Standards Used in the Analyses.
Media
Dust Wipe
Soil (Bare)
Floors
Window Sills
Window Wells
(Troughs)
Painted components with areas
of deteriorated lead-based
paint* *
Hazard Standards for Comparison
EPA Interim 403 Guidance
i100//g/ft"
* 500 jug/ft2
2800;ug/ft2
^5,000 ppm
Any deterioration present
EPA Proposed 403 Rule
*50//g/fta*
* 250 jug/ft2
None
* 2,000 ppm
1) 2 2ft2 deteriorated for large interior
components; 2) 2 10 ft2 deteriorated
for large exterior components; or 3)
i 1 0% of the (interior or exterior)
surface deteriorated for small
components
* Floor dust wipe samples from uncarpeted floors only.
** The statutory definition of lead-based paint is paint with il.O mg/cm2 lead or 20.5% lead by weight.
Data from the Rochester Lead-in-Dust Study [8], the Comprehensive Abatement
Performance (CAP) Study [21,22], the Rhode Island Health Department1, 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. 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 hi 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
Data from the Rhode Island Health Department was not collected as part of a study, but as part of the lead
program in the State of Rhode Island.
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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.
• Dust samples collected from the interior entryway and kitchen did not significantly
add to information obtained from dust samples collected from the bedroom and play
area.
• 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.
• The exclusion of a window well (trough) 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. The 1995 HUD Guidelines
interpreted "windows" as sampling only the window wells (troughs) and not the
window sills. Different interpretations and standards allow several scenarios under
which a lead hazard screen may be performed including potentially not sampling any
windows. Under the Interim Guidance, a lead hazard screen that samples only
window sills is less effective in identifying potential health hazards than the full risk
assessment. When both the window sills and window wells (troughs) are sampled,
the lead hazard screen is as effective as the risk assessment. Under the Proposed
Rule, the lead hazard screen is as effective as the full risk assessment when window
sills are sampled.
• The combination of using the arithmetic mean to characterize the dust and soil
samples and the lower standards, under the Proposed Rule, seem to provide for an
assessment that maintains the ability to identify health hazards while failing fewer
homes than 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 showed that:
• Type I (false positive) error rates were highest when the maximum value was used to
characterize the true medium average lead level and lowest when the geometric mean
was used. The opposite was true for the Type n (false negative) error rates. The
arithmetic mean error rates were always between the maximum value and geometric
mean error rates.
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• The Type I (false positive) and Type n (false negative) error rates were usually over
25% for all three statistics—geometric mean, arithmetic mean, and maximum value -
when the true medium lead levels were within 20% of the medium standard. This
indicates a large area where incorrect decisions may be made, regardless of the
method used to characterize the dust and soil samples.
• The Type I (false positive) 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 (false positive) 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 (false positive) and Type n (false negative) error
probabilities.
Only the Rochester study data were used in the Objective 3 analysis. This analysis
showed:
• The log-transformed blood-lead concentrations were positively correlated with the
log-transformed dust-lead loadings on the floors, window sills, and window wells
(troughs) in the bedroom, kitchen, and play area.
• The log-transformed kitchen and play area window well (trough) 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 rinding applies to the Rochester Study,
but may or may not be the case for other studies. The reason for the significance of
the play area floor dust in this analysis may be because, in the Rochester study, the
play area floor was the pathway the children were most often in contact. The
conclusion 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.
• The window well (trough) 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 (trough) or window sill may provide enough information
about the lead hazard from the windows.
In summary, dust samples obtained from interior entryways and kitchens did not
significantly add to information obtained from dust samples collected from bedrooms and play
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areas; 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 play
area floors provided the best indication of the lead hazard to a child in the Rochester study (this
may or may not be the case for other studies); removing the window wells (troughs) 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, resulted in an assessment that
provided the same protection as the Interim Guidance, but failed 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, an estimated 890,000 children aged 1 to 5 years still have blood-lead
concentrations greater than or equal to 10 ug/dL [9]. Lead in dust, soil, and paint in their
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
requires EPA to promulgate regulations that identify lead-based paint hazards, lead-contaminated
dust, and lead-contaminated soil [4]. Section 402 of TSCA requires 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 in the process of developing the Section 403 regulations, EPA
issued a notice that contained "information designed to serve as guidance [Interim Guidance]
until the promulgation of the final rule" [4]. This information 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 regulation for Section 402 requiring that a 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 of methods or standards for
carrying out the activities, but listed documents that contained methods/standards appropriate 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, Lead-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
methods for conducting risk assessments and provide standards against which the media samples
collected are to be compared. The 403 Interim Guidance provides some detail on how to conduct
risk assessments and 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 makes no distinction between window well2 and window sill sampling
for a lead hazard screen, only requiring that dust samples be collected from
"windows." The HUD Guidelines distinguishes 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 risk assessment and lead hazard screens, Section 402 makes no distinction
between sampling dust from carpeted and uncarpeted floors, only requiring that dust
samples be collected from "floors." The HUD Guidelines distinguishes 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:
Throughout the document, the terms "window sill" and window well" will be used. For clarity, the
definition of each term is given below:
Window Sill: The portion of the horizontal window ledge that protrudes into the interior of the room,
adjacent to the window sash when the window is closed [23]. Also referred to as "window stool."
Window Well: The portion of the horizontal window sill that receives the window sash when the window
is closed, often located between the storm window and the interior window sash [23]. Also referred to as a
"window trough" or "window channel."
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1. While the Interim Guidance made no 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
3. The soil standard was decreased from 5,000 ppm in the Interim Guidance to 2,000
ppm in the Proposed Rule
4. In the Proposed Rule, 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, whereas in the Interim Guidance, each
individual sample result was compared to the relevant standard.
The purpose of this task was 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 Wells
(Troughs)
Painted components with areas
of deteriorated lead-based
paint'*
Hazard Standards for Comparison
EPA Interim 403 Guidance
2lOO//g/ftz«
2500 pg/ft2
2800//g/ft*
25,000 ppm
Any deterioration present
EPA Proposed 403 Rule
250jt/g/ft"
2250pg/ft2
None
* 2,000 ppm
1) 22ft2 deteriorated for large interior
components; 2) 2 1 0 ft* deteriorated
for large exterior components; or 3)
2 10% of the (interior or exterior)
surface deteriorated for small
components
* Floor dust wipe samples from uncarpeted floors only.
** The statutory definition of lead-based paint is paint with 2! .0 mg/cm2 lead or 20.5% lead by weight.
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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 |ig/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
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 provides a
standard for carpeted floors; in fact, the Proposed Rule explicitly states that a standard for
carpeted floors was not included. Data for carpeted floors were included in the analysis to assess
sampling that may be conducted under the HUD Guidelines.
1.1 OBJECTIVES
The overall objective of the analyses discussed in this report were to evaluate some of the
choices a risk assessor may make when identifying lead hazards in a single family home and to
evaluate the differences between the 403 Proposed Rule and the 403 Interim Guidance. This
includes evaluating 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 the way different sampling protocols affect a) the probability of
correctly concluding that an environmental lead hazard exists (defined for purposes
of this analysis as the presence of a child with a blood-lead concentration greater than
or equal to 10 ng/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
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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 hi 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 risk assessors 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 fulfill Objective 1. Within-home variance
estimates and probability estimates of 1) a risk assessment concluding that a home has lead-based
paint hazards when the home does not (Type 1, or false positive, error) and 2) a risk assessment
concluding that a home has no lead-based paint hazards when the home, in fact, does (Type n, or
false negative, error) were used to fulfill Objective 2. Correlation and structural equation
modeling (pathways modeling) were used to fulfill Objective 3.
1.2 STRUCTURE OF THE REPORT
Data from the Rochester Lead-in-Dust Study [8] 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 [21,22]
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 hi 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 are 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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1.3 PEER REVIEW
Prior to publication, this report was reviewed by four individuals with knowledge and
expertise in the subject matter of the report but who were not involved in the development of the
report. Reviewers conducted then- assessments independently of each other. Following is a
summary of reviewer comments that had an important impact on the report and the responses
made to these comments.
Adding Additional Analysis
One reviewer suggested that additional analyses could be performed on the Department
of Housing and Urban Development (HUD) Lead-Based Paint Hazard Control Grant Program
(HUD Evaluation Study) data. Though this was recognized as a very good suggestion, at the
time that this report was written, the data availability was not adequate to ensure suitability for
inclusion in the analysis.
The performance characteristic analysis in this report was run using a blood lead level of
10 ug/dL, the elevated blood lead level at which no environmental intervention is recommended
by the Centers for Disease control (CDC). One reviewer suggested that the performance
characteristics analysis should also be run using a blood-lead level of 15 ug/dL because this is
the environmental intervention blood-lead level used by CDC and HUD. Though this is a good
suggestion, budget and time constraints prevented running this analysis for this report.
Adding Additional Information
One reviewer suggested including the article, "The Contribution of Lead-Contaminated
House Dust and Residential Soil to Children's Blood Lead Levels," by Lanphear, et al. [24], as a
reference. This article assessed 12 epidemiological studies of childhood lead exposure to
determine the contribution of lead-contaminated house dust and residential soil to children's
blood-lead levels. A pooled analysis was used to confirm that lead-contaminated house dust (i.e.,
interior household floor dust-lead loadings) is a major source of lead exposure for children.
Because this analysis did not examine the contribution of floor dust in different rooms, it is hard
to compare the results in this article with the results of the pathways analysis in this report. The
pathways analysis found play area floor dust lead to be a significant pathway of lead exposure for
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children when only floor dust lead was considered to be a source of lead exposure for children.
Nevertheless, the Lanphear article was added as a reference for this report.
Clarification of Terms
One reviewer asked what "gray areas" were when included in the discussion of the Type I
(false positive) and Type n (false negative) error probability analysis. Gray areas are the ranges
of observed levels for which there is a high probability of making an incorrect decision. For
instance, the floor dust standard is 100 ug/ft2. A gray area around this standard could ± 20%, i.e.,
80 ug/ft2 to 120 ug/ft2. If the Type I (false positive) error rate is high in this area, then there is a
good chance that an incorrect decision about the existence of a lead hazard could be made.
"Gray areas" are described in the text.
Questions About Results or Interpretations
One reviewer disagreed with one of the conclusions of the report—i.e., that the arithmetic
mean, under the Proposed 403 Rule guidance, provides an assessment that had the same
protection as the maximum value under the Interim Guidance Rule, but failed fewer homes. The
reviewer suggested that the use of the arithmetic mean masked the location of the specific area
that may be causing the home to fail, thus causing the homeowner to spend more money
removing lead hazards. Though the arithmetic mean may be used to determine whether a lead
hazard exists in a home for any one medium, the lead levels in the individual samples are
available from the laboratory analysis and can be assessed by the risk assessor to pinpoint the
areas that may have to be cleaned. Therefore, use of the arithmetic mean does not mask the
location, but is used as a reporting mechanism for determining the existence of a lead hazard in
the home.
The same reviewer felt that too many homes may pass a risk assessment when they
should have failed, if the arithmetic mean is used. It is true that more homes will fail a risk
assessment when the maximum value is used, but the positive and negative predictive values in
the performance characteristic analysis indicate that when the maximum value is used 1) more
homes that should have passed the risk assessment fail and 2) more homes that should have
failed, pass. The error probabilities analysis showed that the use of the arithmetic mean under
the Proposed Rule guidance improved the discrimination of the risk assessment by reducing the
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Type I (false positive) and Type II (false negative) errors when compared to the maximum value.
Also the discrimination of the maximum value was shown to be dependent on the number of
samples collected; i.e., better discrimination as the number of samples collected increases, while
the arithmetic mean is less dependent on the number of samples collected.
A key assumption of the error probability analysis—no room in a home was more
indicative of the dust-lead hazard available to a child than any other room in a home—was
questioned by two reviewers. This assumption was made to permit assessing the impact of any
one room on the dust-lead hazard to a child without introducing any constraints. In different
parts of the country, different constraints may be placed on the room that has more impact on the
child's blood-lead concentration. For instance, one reviewer pointed out that in California and
other Western states, a child's primary play area may consist of a porch, patio, or balcony, while
in the Rochester Study, the primary play area may be the child's bedroom.
One reviewer, familiar with the Rochester data, questioned the performance characteristic
analysis of 2, 3, or 4 rooms. The reviewer felt that when adding entryways and kitchens, few
additional window sill or window well samples were included in the analysis. This is true. In
the 83 homes included in this analysis, few window sill or window well samples were collected
in interior entryways and kitchens. In many of these homes, though, floor samples were
collected in these rooms. Since the focus of the analysis was on the impact of overall sampling
in additional rooms, and not on specific components, the fact that window sill and window well
samples were not collected was not considered a hindrance in the analysis. Ideally, each
additional room would have had a floor, window sill, and window well dust sample taken; but
since the data were not collected specifically for this analysis, the best available information was
used.
A reviewer pointed out that, when identifying paint-lead health hazards in the
performance characteristic and error probability analysis, the distribution of the paint-lead
concentration, as well as the distribution of the paint deterioration percentage, would better
quantify differences. The report was not aimed at analyzing paint-lead concentrations, and there
was no possibility of assessing paint deterioration distributions since the Rochester data were
only reported as a categorical variable (1=0% to <5% deteriorated painted surface, 2 = s>5% to
s 15% deteriorated painted surface, and 3 = >15% deteriorated painted surface). Another
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reviewer asked for an analysis using the Proposed Rule paint deterioration standard of >10%;
but, again, because of the limitations of the data, this was not possible.
In the summary of the phone survey of risk assessors in the United States, one reviewer
pointed out that some of the risk assessors reported collecting fewer samples than may be
legitimate for a risk assessment. The numbers reported are the numbers collected in the phone
survey and reflect what the risk assessors contacted were doing, on average, at the time of the
call. Another reviewer questioned why only nine risk assessors were called. This was a result of
time and budget constraints. Due to these constraints, it was thought that some information from
around the country was better than no information. It is recognized throughout the discussion of
the phone survey that the information presented is not statistically representative of the
population of risk assessors in the United States.
Other Comments
Other changes to the report based on the reviewers' comments included the following:
• Added footnotes to several tables in Chapter 6 and Appendix G indicating sample
sizes in the analysis.
• Added a footnote explaining that the Rhode Island data were not collected as part of
a study, but were collected as part of the lead program in the State of Rhode Island.
• Discussed the potential differences in recovery rates between actual composite
samples and the simulated composite samples used in the performance characteristic
analysis.
• Discussed the fact that limited data were available that met the data requirements of
the analysis.
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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 (CAP) 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 are 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).
• The average 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.)
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• Paint chip total costs per sample were not reported, even for those contractors that
used paint chip samples in their assessments. For those assessors that performed
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 on how
contractors collected the samples 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 were
sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).
Briefly,
a) Sensitivity is the probability that lead-based paint hazards have been found in the
home given that there is a child with an elevated blood-lead concentration in the
home
b) Specificity is the probability that no lead-based paint hazards have been found in the
home given that there is a child with a low blood-lead concentration in the home
c) PPV is the probability that the child in the home has an elevated blood-lead
concentration given mat lead-based paint hazards have been found in the home
d) NPV is the probability that the child in the home has a low blood-lead concentration
given that no lead-based paint hazards have been found in the home.
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 found fewer homes with lead-based paint
hazards 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's use of the arithmetic mean of dust and soil samples, combined
with the lower media standards, provides a slightly more discriminating, though not
statistically significant, assessment than the Interim Guidance, which uses the
maximum value of the dust and soil samples to compare to higher media standards.
11
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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,
play area, interior entryway, and kitchen) did not significantly improve the
performance characteristics when compared to 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 when the Interim Guidance and Proposed Rule standards are applied.
Table 2-1. Summary of the Performance Characteristics when Dust Samples
are Obtained from Four Room* and Two Rooms in a Home.
Performance
Characteristic
Sensitivity
Specificity
PPV
NPV
Four Rooms
(Bedroom, Play Area, Entryway,
Kitchen)
Interim
Guidance
88.2%
10.7%
22.1%
86.7%
Proposed
Rule
84.7%
74,2%
30.3%
89,1%
Two Rooms
(Bedroom and Play Area)
Interim
Outdance
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 resulted in a
slightly better detection of a lead health hazard when compared to 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 wells was less effective (in terms of sensitivity and NPV) in identifying
potential health hazards than the full risk assessment. When both window sill and
window wells were sampled, the hazard screen (sensitivity = 91.7% and NPV -
89.5%) was as effective as the risk assessment (sensitivity » 91,7% and NPV -
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87.5%), Under the Proposed Rule, when the window sills were sampled, the lead
hazard screen was 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 were
sampled, the Proposed Rule lead hazard screen was not as effective. Note that the
results may be difficult to interpret since the Rochester study homes would 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; ABILITY OF ESTIMATORS AND SAMPLING PROTOCOLS TO
DETERMINE "TRUE" AVERAGE LEAD LEVELS
Data from the Rochester study, the 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 (false positive) error and Type II (false negative) error. Briefly,
a) A Type I (false positive) error is the probability of a risk assessment concluding that
a home has lead-based paint hazards when the home does not
b) A Type II (false negative) error is the probability of a risk assessment concluding
that a home has no lead-based paint hazards when the home in fact does.
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 were drawn from the error probability analysis for each set of
data.
The maximum value had the highest Type I (false positive) and lowest Type II (false
negative) error rates for each medium, the geometric mean had the lowest Type I and
highest Type n error rates, and the arithmetic mean Type I and Type II error rates
always were between the maximum value and geometric mean error rates.
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• Both Type I (false positive) and Type n (false negative) error rates were high
(usually over 25%) for all three statistics when the true media lead 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.
• The Type n (false negative) error probabilities decreased as the number of samples
collected for dust and soil increased from two to four samples, when the maximum
value was used. The Type II (false negative) error probabilities were less dependent
on the number of samples collected when the arithmetic mean and geometric mean
were 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, seemed to have improved the
discrimination of the risk assessment from the 403 Interim Guidance by reducing the
Type I (false positive) and Type n (false negative) error probabilities.
2.3 OBJECTIVE 3: SAMPLING LOCATIONS RISK ASSESSORS MAY WANT TO
TARGET TO EVALUATE POTENTIAL LEAD HAZARDS
A risk assessor has a choice of rooms and components to sample during a risk
assessment. To inform a risk assessor on which rooms and components to sample, this analysis
assessed the rooms and components that significantly impacted the blood-lead concentration of
children in the Rochester Study. Below are the conclusions drawn from this analysis.
• There was 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 structural
equation modeling (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
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
14
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statistically significant indirect pathways of lead exposure. This implies that 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 oflead 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 SAS9 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 SAS9 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 Access9 data base (i.e., entered twice into the data base on two
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separate days). During the data entry, data were verified. 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, the analysis data were
periodically verified 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 evaluating 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 that 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 (CAP) Study
• Baltimore Repair and Maintenance Study (R&M)
• 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
• Milwaukee Low-Cost Intervention Study
• HUD Abatement Demonstration
• HUD National Survey
• 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
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
18
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bach data source. Of all the data that were available for evaluation, only data from the Rochester
tead-In-Dust study and the Rhode Island Department of Health met the criteria.
It should be noted that limited data were available for the analyses in this report,
particularly data meeting the criteria set forth in Appendix F. The collection of such data
through additional environmental studies or local health programs would provide valuable data
for the evaluation of risk analysis protocols.
To obtain cost information associated with Section 402 activities, a phone interview of
risk assessors across the United States was performed. 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 Lead-in-Dust Study was designed to address several objectives: "to
determine whether dust-lead loading (jig/ft2) or dust-lead concentration (p.g/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 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.
19
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Table 4-1. Distribution of the Year Homes were Built and Children's Ages 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%
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].
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 1A 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
foundation sample (in general there were 12 core samples). The soil samples were separated into
20
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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 1-
minute flush. Three XRF paint-lead measurements were taken from areas such as the window
well, sill, and sash; the floor and the door hi 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 complement and contrast with the information
found in the environmental lead studies. To find these additional sources, staff at the CDC
provided a list of 40 health departments in the United States currently participating in its
Childhood Lead Poisoning Prevention Grant Program. A brief questionnaire was developed to
collect information from these departments on the population size of the data base, agencies
funding the program, the availability of the data, the age of children hi the program, whether
blood or environmental (soil, dust, paint, and water) samples were obtained, and the format of
the data.
Following this first survey, a list of 24 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
21
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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 24 health departments requesting
their participation in the data collection effort for the Environmental Protection Agency (EPA)
and explaining how the data would be used in this study. (A c jpy 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 evaluated as to their 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 its ongoing 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 was used in this analysis to ensure that the data could be
reviewed and corrected, as necessary, in time to be included.
As shown in Table K-l of Appendix K, blood, dust, soil, paint, and water samples were
collected and recorded. Two hundred 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 multiple blood samples were logged for one or more children. For
homes in which multiple children were sampled, only the youngest child in the home was
included in the analysis. Generally, a fingerstick blood sample was obtained for comparison
22
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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 toward 20 ng/dL, but 25 fig/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 available, a venous blood sample result was used in the
analysis; otherwise, the fingerstick blood sample result was included.
Table 4-2. Distribution of Children's Ages in the Rhode Island Department of Health Data.
Age of 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 cm 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 furniture for
265 homes. The condition of the painted surface was not reported.
When the data were subset to include all the information needed for the Objectives 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.
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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 ng/dL with 90% of the children having blood-lead concentrations 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 jig/dL, with only 3% of children having
blood-lead concentrations of 20 ug/dL or more. 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 by interviewing
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 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.
24
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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 fig/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 used variability estimates and distributional
assumptions to estimate error probabilities associated with concluding that the true average lead
26
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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 time of this report, Section 402 did not dictate one set of methods for
carrying out activities outlined under Section 402, but listed documents that have appropriate
methods. Two documents contained the prevalent method: the HUD Guidelines and the 403
Interim Guidance. These documents listed nearly the same methods 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 described 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. The Section 403 Interim Guidance was recommended as a Section 402
guidance document at the time these analyses were conducted. 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 are 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
27
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nine States were contacted and interviewed in May 1997. The sample of contractors 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 interviews, some respondents did not answer all the questions posed.
Follow-up calls were made in April 1998 to 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 for the May 1997 calls, with
additional discussion of the information gathered from the April 1998 interviews provided where
appropriate.
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
Nine contractors from across the country 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 hi the northeast region, three contractors in
the south region, and two contractors in the west region. Within each region, the IDs 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
Contractors allocated costs for an activity in two ways:
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
28
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required, the contractor charged additional fees. Some contractors opted to charge separate 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, 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 the 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 used.
5.1.1.4 Number of Environmental Samples Collected
The responses to questions B6, B9, B13, C6, C9, C13, D6, D9, D13, E7, E10, 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
29
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reported for the number of samples collected, the same strategy as discussed for the cost per
sample was employed.
5.1.2 Performance Characteristics
Four measurements (performance characteristics) (sensitivity, specificity, PPV, and 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
Target
Blood Lead
Concentration
2lO//g/dL
<10//g/dL
Media Standard
Below «) Media
Standard
a
c
Above (;>) Media
Standard
b
d
In the above table, the letter 'a' represents the number of children that have a blood-lead
concentration above a given target and the media lead level (soil-lead concentration, etc.) below
the selected standard. Letters 'b,' 'c,' and 'd' represent similar counts. From these counts the
following performance characteristics are calculated:
Performance
Characteristic
Sensitivity
(or True Positive Rate)
Specificity
(or True Negative
Rate)
Positive Predictive
Value (PPV)
Negative Predictive
Value (NPV)
Definition
Probability that lead-based paint hazards are
found in the home given that there is a
resident child with an elevated blood-lead
concentration.
Probability that no lead-based paint hazards are
found in the home given that a resident child
has a low blood-lead concentration.
Probability of a resident child having an
elevated blood-lead concentration given that
lead-based paint hazards are found in the
home.
Probability of a resident child having a low
blood-lead concentration given that no lead-
based paint hazards are found in the home.
Calculation
b/(a + b)
c/(c + d)
b/(b + d)
c/(a + c)
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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 an example 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
evaluated based primarily on sensitivity and NPV measures. The sensitivity focuses on the
probability of finding lead-based paint hazards 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 no lead-based paint hazards have been found.
8
g
i
&
so
40
30
20
10
. t
400 600 1.200 1.600
Drlpline Soil-Lead Concentration Oxg/g)
2.000
2.400
Figure 5-1. Example of an Ideal Situation When 100% is Achieved For All
Four Performance Characteristics.
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5O-
40
J 30-
5
10
400 800 1.200 1.600
Dripline Soil-Lead Concentration (Mfi/8)
2.000
2.400
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 [2]. Using the variables defined in Table 5-1, the
confidence limits were calculated as follows:
where
B
n
Lower Confidence Limit: Pl(n, B) =
B
,,,
B
Upper Confidence Limit: P£(W, B) = 1 - 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)
the upper yth percentile for the F distribution with n, numerator degrees of
freedom and r\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 options available to a risk assessor 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 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 proposed 403 Rule is used, paint standard is greater than 10%
deteriorated lead-based paint, and no differentiation is made between interior and exterior painted
components. In the Rochester study data, the condition of the paint was reported as good (from
0% to less than 5% deteriorated paint), fair (5% to 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).
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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.
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:
1. 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.
2. 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).
3. Assessment of the deteriorated paint condition levels in the HUD Guidelines versus
other options for deteriorated paint condition levels.
4. 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 were used when only
single sample data were 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, for a lead hazard screen, comparing composite floor
dust, window dust samples, and samples from deteriorated painted surfaces to their respective
standards. Section 402 does not make a distinction among the types of floors or window
components that should be sampled. The 1995 HUD Guidelines present a method 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
34
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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 method for sampling from a 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 5-2, 5-3,
and 5-4. Composite samples were not collected hi the Rochester study, so to perform the
assessment in 4. above, the arithmetic mean of the uncarpeted and carpeted floor dust samples,
window sill dust samples, window well dust samples, and paint samples were used as surrogate
composite samples to compare to the lead hazard screen standards, depending on the scenario
chosen. A composite sample is different from a single-surface sample in that samples are
collected from common components in different rooms and analyzed as one sample. As a result,
there may be potential differences in lead recovery rates for composite samples compared to
surrogate composite samples. The Proposed Rule also 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.
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.
35
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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
Bedroom, Play Area
Soil
Dripline &
Play Area
Dripline &
Play Area
Dripline &
Play Area
Paint
>15% or 26% of
the painted surface
is deteriorated
>15% or 25% of
the painted surface
is deteriorated
>15% or 26% 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 5-3. 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 2:5% of
the painted surface
is deteriorated
>15% or 26% of
the painted surface
is deteriorated
>15% or 26% 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 5-4. 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
C-2
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 26%
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 5-5. Summary of the Statistics Calculated to Characterize the Protocols.
Statistic to Characterize the Protocol
Number of Homes Included in the Analysis
% of Homes in which Lead-Based Paint Hazards
were Found
% of Blood Samples *10//g/dL
% of Homes in Which Lead-Based Paint Hazards
Were Found Based on One Medium Assessed
Individually (* media standard)
Sensitivity (LCB, UCB)
Specificity (LCB, UCB)
Positive Predictive Value {LCB, UCB)
Negative Predictive Value (LCB, UCB)
Estimated cost of a risk
assessment or lead hazard
screen
Basic Fee
Separate Fee
Description of the Calculation
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 10//g/dL.
For each medium individually, this is the percent of
homes that have at least one sample that 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. (See Section 5.1 .1 .2.)
Estimated cost of a risk assessment or lead hazard
screen performed under the protocol when separate fees
are charge for the activity. (See Section 5.1 .1 .2.)
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5.2 OBJECTIVE 2; ABILITY OF ESTIMATORS AND SAMPLING PROTOCOLS TO
DETERMINE TRUE AVERAGE LEAD LEVELS
The statistical analysis for this objective used 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:
1. Compared the ability of the maximum value, geometric mean, and arithmetic mean
to characterize floor dust, window sill dust, and window well dust lead loadings
and soil lead concentration.
2. Characterized a) the probability of no lead-based paint hazards being found in the
home when the unobservable, "true" media lead level at the home is assumed to be
above the media standard (Type n error or false negative) and b) the probability of
finding lead-based paint hazards in the 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).
3. 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.
38
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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. This assumption is
based on previous studies that have shown that dust-lead loadings and soil-lead
concentrations are often well-described by a lognormal distribution [18].
2. No one room in a home was more indicative of a child's dust lead exposure than
any other room in the home. This assumption was made to allow the impact of any
one room on the dust-lead hazard to a child to be assessed without introducing any
constraints. 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
-------
H,, the home's unobservable, "true" lead level for medium/component i is assumed to be above
or equal to the medium/component standard. Of interest are the probabilities of correct and
incorrect decisions based on the estimated medium/component lead level at the home. These
probabilities are based on the Type I (false positive) and Type IT (false negative) error
probabilities.
P (Type I or false positive error) = P(reject H0 | H0 is true)
= P(Y, * Si | m < SJ
P (Type II or false negative error) = P(do not reject H01 H, is true)
= P(Ya < Si | Ui * Si)
where Yy is the estimated average lead level in the home for component/medium i and
statistic^' and the remaining terms are as defined above.
Note that the probabilities depend on the assumed, "true" lead level at the house (m). To
calculate these probabilities, the following information is needed:
1. The sampling distribution of the three estimators (maximum value, arithmetic mean,
geometric mean) of ji
2. Estimates for the within-house variation (o) for each medium/component
3. An assumption about the unobservable, "true" lead levels in the house.
Appendix L provides descriptions of the sampling distributions of the estimators (maximum
value, arithmetic mean, geometric mean) of n. The within-house variation calculations, o, are
discussed below. To calculate the Type I error probabilities, the unobservable, "true" average
lead levels in the home are assumed to be less than the media/component standard. To calculate
the Type II error probabilities the unobservable, "true" average lead levels are assumed to be
greater than or equal to the medium/component standard.
The error probabilities are calculated for a risk assessment, "simple" lead hazard screen,
and a "compound" lead hazard screen. "Simple" and "compound" lead hazard screens are
defined below. To summarize the error probability calculations, graphs and tables are provided
comparing the error probabilities associated with each estimator for various assumed "true" lead
levels in the home for each medium/component.
40
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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 medium/component was modeled as
log(Y) = u + r + e,
where
Y is the observed dust-lead or soil-lead level and is assumed to follow a normal
distribution with mean \L and variance o2 = o2r + a
•2
€
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
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 O2e (within-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 + O2€, where o2 is
the within-house variation. Note that this implies that 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 4.2, dust
41
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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.
Table 5-6. Data Used for Calculating 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
Foundations
Boundaries
Floor
Window Sill
Window Well
Side of House/ Foundations
Number of
Houses
204
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" [18].
2 Mixed models were fitted to the data 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 had only 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
42
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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
in Table 1-1. One exception to both the Interim Guidance and Proposed Rule made in this
analysis was to include and compare both uncarpeted and carpeted floors to the standard
presented for the uncarpeted floors. In addition, the Proposed Rule makes a distinction between
play area soil and mid-yard soil. The CAP Study data only makes a distinction between
foundation and boundary soil. Therefore, for this analysis the boundary soil was considered 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 lead hazard screen finds lead-based paint hazards in a home, the
home is required to undergo a full risk assessment. The probability that a lead hazard screen
incorrectly finds lead-based paint hazards or no lead-based paint hazards is called the "simple"
lead hazard screen error probability. A "compound" lead hazard screen error probability is the
probability of the risk assessment finding lead-based paint hazards or no lead-based paint
hazards, given that the lead hazard screen found lead-based paint hazards in the home (i.e., the
probability that a home is assessed to have lead-based paint hazards or no lead-based paint
hazards when a lead hazard screen indicated a lead-based paint hazard.
Since the "simple" lead hazard screen merely determines whether or not a home has lead-
based paint hazards on the basis of a lead hazard screen, only Type I (false positive) error
probabilities are presented in Section 6.2.2.2. Type I and n (false positive and false negative)
error probabilities are presented for the "compound" lead hazard screen. To calculate the
"compound" lead hazard screen error probabilities, an assumption was made that the
measurements taken during a lead hazard screening stage are independent from the
43
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measurements taken during the risk assessment stage. Given this assumption, the "compound"
lead hazard screen error probabilities are based on the following compound probabilities.
Since a house is determined to have lead-based paint hazards when the lead hazard screen
finds lead-based paint hazards and then the risk assessment finds lead-based paint hazards, the
probability of a Type I (false positive) error for a "compound" lead hazard screen is:
P(lead hazard screen finds lead-based paint hazards and risk assessment finds lead-based paint hazards |
assumed true lead level < medium standard) =
P(lead hazard screen finds lead-based paint hazards | assumed true lead level < medium
standard)*
P(risk assessment finds lead-based paint hazards | assumed true lead level < medium standard).
Under the above described hypothesis setting, this can be written as
P(Y, * 0/**S.), Z, * 0/**S,) | u, < 0/**S,)) = P(Y, * 0/2*8,) | u, < 0/2*8,)) * P(Z, * 0/**S,) | u, < 0/2*8,)),
where
YJJ is the calculated lead level for medium/component i and statistic./ during lead
hazard screen
Zy is the calculated lead level for medium/component i and statisticy' during risk
assessment
S; is the standard for medium/component i (floor dust, window sill dust, window well
dust, and soil). Note: The lead hazard screen uses '/2 the Interim Guidance or
Proposed Rule standard as a level for comparison.
u.j is the assumed unobservable, "true" lead level in home for medium i.
A house is determined to have no lead-based paint hazards when either the lead hazard
screen initially finds no lead-based paint hazards or when the lead hazard screen finds lead-based
paint hazards, but the risk assessment finds no lead-based paint hazards. As a result, the
probability of a Type II (false negative) error for a "compound" lead hazard screen is:
P(lead hazard screen finds no lead-based paint hazards or
lead hazard screen finds lead-based paint hazards but risk assessment finds no lead-based paint
hazards | true lead level 2 medium standard) =
44
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P(lead hazard screen finds no lead-based paint hazards | true lead level 2 medium standard) +
[P(lead hazard screen finds lead-based paint hazards | true lead level 2 medium standard) *
P(risk assessment finds no lead-based paint hazards | true lead level 2 medium standard)].
Under the above hypothesis setting and the descriptions of Y(j, Z^, Si} and Hj, this can be written
as
P(Y, < * C/a'S.) or Y, * (Vi'S,), Z, < (y2*S.) | M, * C
P(Y, < C/2'S.) | M, * (1/2*S,)) + [P(Y, * (ya*S,) | M, 2 (1/2*S,)) * P(Z, < (ya*S,) | u,
5.3 OBJECTIVE 3: SAMPLING LOCATIONS RISK ASSESSORS MAY WANT TO
TARGET TO EVALUATE POTENTIAL LEAD HAZARDS
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 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 for 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
45
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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.
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 are 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 1, this implied that the linear association between the two variables being evaluated was
strong. If the absolute value of r was near 0, this implied that there was 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.
46
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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 [13,
14,15,16,17].
Bedroom Window
Well Dust
J
Bedroom Window
Sill Oust
Play Area Window
Sill Dust
I
Play Area Window
Well Dust
Bedroom Floor Dust
->. Play Area Floor Dust
->. Kitchen
— Floor Dust
t
BLOOD
Interior Entryway
Floor Dust
Figure 5-3. Pathways of Lead Exposure Investigated Using the Rochester Study Data.
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 assessed hi this
analysis.
47
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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
• 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
• Interior entryway dust via the play area floor dust, bedroom floor dust, or the kitchen
floor dust.
To statistically assess these pathways, a 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
(4) Bedroom Floor Dust = Bedroom Window Sill Dust + Bedroom Window Well Dust +
Play Area Floor Dust + Interior Entryway Floor Dust
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(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)
• 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
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
49
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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 allowed an assessment of the effect of
sampling location on identifying hazards. *
so
-------
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:
1. Average total costs of an activity: risk assessment, lead hazard screen, inspection, and
risk assessment/inspection
2. Average cost per environmental sample
3. Average number of environmental samples collected
4. 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
IDs were 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 shows 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.
51
-------
Risk Assessment
$3,000
W $2.000
(0
O
O $1,500
"w
"o $1.000
$500
$o
$1.520
$659
IS)
|
$1.042
$900
$759 r
$260
|
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2 S-3 W-1 W-2
O Basic Fee • Separate Fee B Overall
$3.000
^ $2,500
j2 $2.000
in
o
O $1.500
5
o $1.000
$500
$o
Inspection
$1,530
$978
±H
n
n
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2 S-3 W-1 W-2
O Basle Fee • Separate Fee B Overall
01
Lead Hazard Screen
ta.uuu •
<- $2,000
10
0
91,OUQ
O 51,000
$500
«n •
$525
¥ ir w 1
$626
$200
,n
$200
n
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2 S-3 W-1 W-2
QBaelc Fee • Separate Fee B Overall
Risk Assessment/Inspection
$3.000 '
$2,500
<2 *^.ooo
0
» l ,OUU
15
O » 1,000
$500
«n -
$:
$1
i
^
^
78
$515
$235 k
n 1
25
$1 onK
$1.318
1 $900
1 $550
1
Overall NE-1 NE-2 NE-3 NE^4 S-1 S-2 S-3 W-1 W-2
D Basic Fee • Separate Fee B Overall
Figure 6-1. Total Costs for a Risk Assessment, Inspection, Lead Hazard Screen, and a Risk Assessment/Inspection.
-------
Table 6-1. Average Total Cost of a Risk Assessment, Lead Hazard Screen, Inspection, and
Risk Assessment/Inspection With and Without Extremely High Costs.
Activity
Risk Assessment
Lead Hazard Screen
Inspection
Risk Assessment/Inspection
Average Total Cost ($)
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. The large disparity in prices among
the contractors appears to be related to the extensiveness of lead poisoning 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 that 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.
53
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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.
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 who charged separate costs for each component of an
activity generally had higher costs than those that charged the basic fee.
54
-------
Risk Assessment
$600
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2 S-3 W-1 w-2
Sf $1.200
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2 S-3 W-1 W-2
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2 S-3 W-1 W-2
Figure 6-2. Estimated Costs ($) of the Visual Assessment, Typical Environmental
Sampling, and the Risk Assessment Report for a Risk Assessment.
55
-------
Lead Hazard Screen
$250 T
$0
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.
56
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Inspection
$800
o
o
o
JS
$750
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2 S-3 W-1 W-2
O
a.
E
5
I
III
5
X
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2 S-3 W-1 W-2
$600
$380
$500
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2 S-3 W-1 W-2
Figure 6-4. Estimated Costs ($) of the Visual Assessment, Typical Environmental
Sampling, and the Inspection Report for an Inspection.
57
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Risk Assessment/Inspection
M
o
o
1
e
•
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2 S-3 W-1 W-2
S» $1.400 -i
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2 S-3 W-1 W-2
Overall NE-1 NE-2 NE-3 NE-4 S-1 S-2 S-3 W-1 W-2
Figure 6-5. Estimated Costs ($) of the Visual Assessment, Typical Environmental
Sampling, and the Risk Assessment/Inspection Report for a Risk
Assessment/Inspection.
58
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6.1.1.2 Summary of the Costs per Environmental Sample
Table 6-2 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.
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-$20.00
$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)
(b)
(b)
$25.00
$25.00-$25.00
$19.50
$18.50-$20.00
(b)
(b)
Inspection
$17.40
$5.00-$25.00
$15.00
$15.00-$ 15.00
(b)
(b)
(b)
$18.50
$18.50-$18.50
$25.00
$25.00-$25.00
$18.50
$18.50-$18.50
$5.00
$5. 00- $5. 00
(b)
Risk Assessment/
Inspection
$16.43
$5.00-$30.00
$15.00
$15.00-$ 15.00
$10.00
$10.00-$ 10.00
(b)
$20.00
$20.00-$20.00
$22.88
$16.50-$30.00
$25.00
$25.00-$25.00
$19.40
$18.50-$20.00
$5.00
$5.00-$5.00
$15.00
$15.00-$ 15.00
' No paint costs were available for any of the activities.
b The costs for the activity were not reported by the contractor.
59
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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 $25 for a
contractor in the south region. Generally, across the four activities, the costs per sample
remained nearly the same for a given contractor.
Table 6-3 presents the average collection cost, average analysis cost, and average total
cost, per environmental sample, for each of the media/components sampled. As discussed in
Section 5, the total cost was the sum of the collection and analysis costs. Because only one
contractor reported collection costs separately, total costs typically reflect just the cost of
analysis.
Table 6-3. Average Cost Per Sample Collected for Sampling Performed by a Certified Risk
Assessor During a Risk Assessment, Lead Hazard Screen, Inspection, or Risk
Assessment/Inspection For All Contractors.
Media
Dust
Paint
Soil
Water
Type of Sample
Composite
Single
Paint Chips -
Composite
Paint Chips -
Single
XRF
Composite
Single
Average Cost Per Sample ($)
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
IN = 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
IN = 7)
(a)
$13.18
$ 5.00 - $25.00
(N = 5)
3 No cost was reported by any contractor. (See text for paint cost information obtained in follow-up
interviews.)
60
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Table 6-3 shows that the average total costs per environmental sample were highest for
the three contractors who 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 ctust, 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 charged $50 per hour for XRF testing, two others charged a
flat fee of $200 and $365 for XRF sampling, and two other contractors charged $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 five for a lead hazard screen to 42 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.
61
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Table 6-4. 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)
(a)
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)
a The number of samples collected for the activity was not reported by the contractor.
b 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 1 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 the 1997 updates to the HUD Guidelines. Similar summaries are provided in Tables
G-l through G-9 in Appendix G for each of the contractors.
62
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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/Inspection For 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)
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 5-2, 5-3,
and 5-4, 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)
3. The outcome of a full risk assessment versus the outcome of a lead hazard screen
(Sampling Protocol C)
63
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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
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 that 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 full
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 found to have lead-based paint hazards and the
protectiveness of the sampling. The number of homes found to have lead-based paint hazards
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 the effect of the additional rooms in sampling does not
64
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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
Number of Individual Dust Samples /
Homes
% of Homes in Which Lead-Based Paint
Hazards Were Found
(# Homes Below Standards / # Homes)
% of Blood Samples 210/sg/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 in Which Lead-Based Paint Hazards Were Found Based on Media Standards (* Media Standard)
{# of Homes Below Media Standard / # 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 (26% deteriorated)
9.6% (8/83)
3.9% (3/76)
7.3% (6/82)
21.7% (18/83)
81.9% (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)
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)
Performance Characteristics
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%)
88.2%
(63.6%, 98.5%)
15.2%
(7.5%, 26.1%)
21.1%
(12.3%, 32.4%)
83.3%
(51.6%, 97.9%)
Notes: 1. For 2, 3, and 4 rooms, respectively, 6, 7, and 8-9 dust wipe samples were obtained from floors,
window sills, and window wells. Three core soil samples were taken on each side of the house (in
general there were 12 core samples) and combined for a composite sample. Three XRF paint-lead
measurements were taken from various surfaces, and the three measurements for each surface
were averaged.
2. See Table 5-2 for definitions of sampling protocols A-1, A-2, and A-3.
65
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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 Dust Samples per
Home
% of Homes in Which Lead-Based Paint
Hazards Were Found
(# Homes Below Standards / # Homes)
% of Blood Samples * 1 0 /sg/dL
Sampling Protocol Group A
A-1 (4 Rooms)
83
8-9
77.1%
A-2 (3 Rooms)
83
7
75.9%
A-3 (2 Rooms)
83
6
74.7%
20.5%
% of Homes in Which Lead-Based Paint Hazards Were Found Based on Media Standards (2 Media Standard)
(# of Homes Below Media Standard / # 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 (28% 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)
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)
79.7% (51/64)
Performance Characteristics
Sensitivity
(LCB, UCB)
Specificity
(LCB, UCB)
Positive Predictive Value
(LCB, UCB)
Negative Predictive Value
(LCB, UCB)
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%)
82.4%
(56.6%, 96.2%)
27.3%
(17.0%, 39.6%)
22.6%
(12.9%, 35.0%)
85.7%
(63.7%, 97.0%)
Notes: 1. For 2, 3, and 4 rooms, respectively, 6, 7, and 8-9 dust wipe samples were obtained from floors and
window sills. Window well samples are not required under the Proposed Rule. Three core soil
samples were taken on each side of the house (in general there were 12 core samples) and
combined for a composite sample. Three XRF paint-lead measurements were taken from various
surfaces, and the three measurements for each surface were averaged.
2. See Table 5-2 for definitions of sampling protocols A-1, A-2, and A-3.
3 NA indicates that these samples were not included in the analysis.
66
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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 in Which
Lead-Based Paint Hazards
Were Found
Performance Characteristics
Sensitivity
Specificity
Positive Predictive
Value
Negative Predictive
Value
Sampling Protocol Group A
Interim Guidance
A-1
(4 Rooms)
A-2
(3 Rooms)
A-3
(2 Rooms)
Proposed Rule
A-1
(4 Rooms)
A-2
(3 Rooms)
A-3
(2 Rooms)
83
81.9%
88.2%
19.7%
22.1%
86.7%
80.7%
88.2%
21.2%
22.4%
87.5%
80.7%
88.2%
21.2%
22.4%
87.5%
33.7%
64.7%
74.2%
39.3%
89.1%
32.5%
58.8%
74.2%
37.0%
87.5%
30.1%
58.8%
77.3%
40.0%
87.9%
Note: See Table 5-2 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.
67
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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 in which lead-
based paint hazards were found when the entryway was sampled after the bedroom and play area
had been sampled and when the 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 were found to have
lead-based paint hazards 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 in Which Lead-Based Paint Hazards Were Found
When the Entryway and Kitchen Were Sampled.
Component
Floors
Carpeted
Uncarpeted
Window Sills
Window Wells
Number of Additional Homes Found to Have Lead-Based Paint Hazards
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 are collected when
only examining 2 rooms (e.g., 2 samples in 2 rooms or 4 samples in 4 rooms) the results may be
different.
The differences observed between the Interim Guidance and Proposed Rule performance
characteristics are discussed in Section 6.1.2.4.
68
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6.1.2.2 Results of Protocol B Analysis: Assessment of the Impact of Various Methods
of Characterizing Dust Wipe 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 HUD's 1995 Guidelines, a home is determined to have lead-based paint hazards
if any sample does not pass the standards outlined in each document. Under EPA's Proposed
Rule, a home is determined to have lead-based paint hazards 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 for a full risk assessment (XRF samples taken from
surfaces with k5% deteriorated paint) using the Interim Guidance and Proposed Rule standards,
respectively.
Tables 6-10 and 6-11 show that the percentage of homes found to have lead-based paint
hazards is 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 found to have lead-based paint hazards 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, ranged from 73.2% for the geometric mean to 79.5% for the
maximum value. For both standards, the percentage of homes found to have lead-based paint
hazards when using the arithmetic mean was between the geometric mean and maximum value
findings.
69
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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 in Which Lead-Based Paint
Hazards Were Found
(# Homes Below Standards / # Homes)
% of Blood Samples 2 1 0 //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 in Which Lead-Based Paint Hazards Were Found Based on Media Standards (z Media Standard)
(# of Homes Below Media Standard / # Homes in Which Samples Were Collected)
All Floors
Carpeted Floors Only
Uncarpeted Floors Only
Window Sill
Window Well
Soil
Oripline 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% (76/112)
7.6% (8/105)
7.7% (8/104)
0% (0/52)
77.3% (68/88)
3.6% (4/112)
1.0% (1/102)
2.8% (3/109)
22.3% (25/112)
75.9% (85/112)
7.6% (8/105)
7.7% (8/104)
0% (0/52)
77.3% (68/88)
8.0% (9/112)
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%)
Notes: 1. Floor, window sill, and window well samples were collected as dust wipes. All available dust
samples (wipe) taken in the bedroom, play area, entryway, and kitchen were included in the
analysis. Three core soil samples were taken on each side of the house (in general there were 12
core samples) and combined for a composite sample. Three XRF paint-lead measurements were
taken from various surfaces, and the three measurements for each surface were averaged.
2. See Table 5-3 for definitions of sampling protocols B-1, B-2, and B-3.
70
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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
Deteriorated Paint).
# Homes Included in Analysis
% of Homes in Which Lead-Based Paint
Hazards Were Found
(# Homes Below Standards / # Homes)
% of Blood Samples * 1 0 /jg/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 in Which Lead-Based Paint Hazards Were Found Based on Media Standards U Media Standard)
(# of Homes Below Media Standard / # 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 te 5% deteriorated)
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)
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
ILCB, UCB)
Specificity
(LCB, UCB)
Positive Predictive Value
ILCB, 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%)
Notes: 1. Floor and window sill samples were collected as dust wipes. Window well samples are not
included in the Proposed Rule sampling scheme. All available dust samples (wipe) taken in the
bedroom, play area, entryway, and kitchen were included in the analysis. Three core soil samples
were taken on each side of the house (in general there were 12 core samples) and combined for a
composite sample. Three XRF paint-lead measurements were taken from various surfaces, and the
three measurements for each surface were averaged.
2. See Table 5-3 for definitions of sampling protocols B-1, B-2, and B-3.
3 NA indicates that these samples were not included in the analysis.
71
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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 (15.9%) while the
geometric mean was lowest (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, there were not large differences
in the performance characteristics among 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 of the various summary methods
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).
# Homes Included in Analysis
% of Homes in Which Lead-
Based Paint Hazards Were
Found
Sampling Protocol Group B
Interim Guidance
B-1
(Geometric
Mean)
B-2
(Arithmetic
Mean)
B-3
(Maximum
Value)
Proposed Rule
B-1
(Geometric
Mean)
B-2
(Arithmetic
Mean)
B-3
(Maximum
Value)
112
67.9%
75.9%
Performance Characteristics
Sensitivity
Specificity
Positive Predictive Value
Negative Predictive Value
70.8%
33.0%
22.4%
80.6%
79.2%
25.0%
22.4%
81.5%
83.0%
31.3%
35.7%
57.1%
91.7%
19.3%
23.7%
89.5%
54.2%
75.0%
37.1%
85.7%
62.5%
71.6%
37.5%
87.5%
75.0%
47.7%
28.1%
87.5%
Note: See Table 5-3 for definitions of sampling protocols B-1, B-2, and B-3.
72
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When they are based only on the dust samples, differences in performance characteristics
are more pronounced. Under the Interim Guidance, the sensitivity increased from 79.2% to
91.7% when using the maximum value rather than the arithmetic mean and NPV increased from
81.5% to 89.5%. Under the Proposed Rule, the percentage of homes found to have lead-based
paint hazards increased from 35.7% to 57.1% when using the maximum value rather than the
arithmetic mean and the sensitivity increased from 62.5% to 75%.
The differences observed in the percentage of homes found to have lead-based paint
hazards and the performance characteristics for the two sets of standards are discussed below.
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 (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 is 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. The different standards
and interpretations result in various scenarios under which a lead hazard screen could be
performed including potentially sampling no windows. Tables 6-13 and 6-14 assess the various
choices a risk assessor could make when performing a lead hazard screen.
73
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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 2>5% Deteriorated Paint).
# Homes Included in Analysis
% of Homes in Which Lead-
Based Paint Hazards Were
Found
(# Homes Below Standards / #
Homes)
% of Blood Samples ;>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 in Which Lead-Based Paint Hazards Were Found Based on Media Standards
(# of Homes Below Media Standards / # 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 (2 5% deteriorated)
8.0% (9/112)
3.9% (4/102)
5.5% (6/102)
27.7% (31/112)
83.0% (93/112)
7.6% (8/105)
7.7% (8/104)
0% (0/52)
77.3% (68/88)
8.9% (10/112)
2.9% (3/102)
7.3% (8/109)
NA
82.1% (92/112)
NA
NA
NA
77.3% (68/88)
8.9% (10/112)
2.9% (3/102)
7.3% (8/109)
32.1% (36/112)
NA
NA
NA
NA
77.3% (68/88)
8.9% (10/112)
2.9% (3/102)
7.3% (8/109)
32.1% (36/112)
82.1% (92/112)
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%, 99.0%)
15.9%
(9%, 25%)
22.9%
(15%, 33%)
87.5%
(62%, 98%)
87.5%
(67%, 97%)
17.0%
(10%, 27%)
22.3%
(14%, 32%)
83.3%
(59%, 96%)
83.3%
(62%, 95%)
37.5%
(27%, 49%)
26.7%
(17%, 38%)
89.2%
(75%, 97%)
91.7%
(73%. 99%)
19.3%
(12%, 29%)
23.7%
(16%, 34%)
89.5%
(67%, 99%)
Notes: 1. Floor, window sill, and window well samples were collected as dust wipes. All available dust
samples (wipe) taken in the bedroom, play area, entryway, and kitchen were included in the analysis.
Three core soil samples were taken on each side of the house (in general there were 12 core
samples) and combined for a composite sample. Three XRF paint-lead measurements were taken
from various surfaces, and the three measurements for each surface were averaged.
2. See Table 5-4 for definitions of sampling protocols C-1 and C-2.
3. NA indicates that these samples were not included in the analysis.
74
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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 in Which Lead-Based Paint
Hazard Were Found
{# Homes Below Standards / # Homes)
% of Blood Samples i10//g/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 in Which Lead-Based Paint Hazards Were Found Based on Media Standards
(# of Homes Below Media Standards / # 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 (26% deteriorated)
8.9% (10/112)
2.9% (3/102)
7.3% (8/109)
32.1% (36/112)
NA
27.6% (29/105)
NA
NA
77.3% (68/88)
30.4% (34/112)
10.8% (11/102)
26.6% (29/109)
NA
NA
NA
NA
NA
77.3% (68/88)
30.4% (34/1 1 2)
10.8% (11/102)
26.6% (29/109)
64.3% (72/112)
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%)
91.7%
(73%, 99%)
25.0%
(16%, 35%)
25.0%
(16%, 35%)
91.7%
(73%, 99%)
Notes: 1. Floor and window sill samples were collected as dust wipes. Window well samples are not included
in the Proposed Rule sampling scheme. All available dust samples (wipe) taken in the bedroom, play
area, entryway, and kitchen were included in the analysis. Three core soil samples were taken on
each side of the house (in general there were 12 core samples) and combined for a composite
sample. Three XRF paint-lead measurements were taken from various surfaces, and the three
measurements for each surface were averaged.
2. See Table 5-4 for definitions of sampling protocols C-1 and C-2.
3. NA indicates that these samples were not included in the analysis.
75
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Most of the homes in the Rochester Study would not have been recommended for a hazard
screen since more than 80% 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 a
sensitivity of 91.7% and an NPV of 87.5%. A lead hazard screen 1) sampling window wells
attained a 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
4. The use of the arithmetic mean in the Proposed Rule to characterize dust and soil
lead levels.
Each of these can have a different and sometimes conflicting effect. For example, lower soil
standards under the Proposed Rule would increase the proportion of homes found to have lead-
76
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based paint hazards, while use of the arithmetic mean under the Proposed Rule may decrease the
proportion of homes found to have lead-based paint hazards.
The purpose of this analysis is to both assess how all changes in the Proposed Rule act
jointly to affect performance characteristics, as well as to discuss the expected effect of the
individual changes.
As discussed above, fewer homes were found to have lead-based paint hazards when the
Proposed Standards were used rather than the Interim Guidance. Sensitivity and NPV remained
high, and specificity and PPV increased 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 finding lead-based paint hazards in a home while reducing the
probability of incorrectly finding lead-based paint hazards in a home.
Lower Dust-Lead and Soil-Lead Standards
To assess the effect that lower dust and soil standards have on 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, more homes were shown to have
lead-based paint hazards with the lower standards; but sensitivity and NPV increased, while
specificity decreased. In the first two columns, 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 were shown to have lead-based paint hazards, with 32.1% a result of window sills and
27.6% a result of 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 were shown to have lead-based
paint hazards, with 22.3% of the homes as a result of window sills and only 7.6% of the homes
for a result of soil. The sensitivity and NPV of 45.8% and 83.5%, respectively, are lower than
for 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.
77
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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.
# Homes Included in Analysis
% of Homes in Which Lead-Based Paint
Hazards Were Found
(# Homes Below Standards / # Homes)
Lead in Dust Characterized by
the Arithmetic Mean
Interim
Guidance
Proposed Rule
Lead in Dust Characterized by
the Maximum Value
Interim
Guidance
Proposed Rule
112
29.5%
52.7% II 36.6%
67.0%
% of Homes in Which Lead-Based Paint Hazards Were Found Based on Media Standards
(# of Homes Below Media Standards / # 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
19.6%
4.9%
16.5%
49.1%
NA
27.6%
NA
NA
NA
Performance Characteristics
Sensitivity
Specificity
Positive Predictive Value
Negative 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%
87.5%
38.6%
28.0%
91.9%
Notes: 1. Floor and window sill samples were collected as dust wipes. Window well samples are not
included in the Proposed Rule sampling scheme. All available dust samples (wipe) taken in the
bedroom, play area, entryway, and kitchen were included in the analysis. Three core soil samples
were taken on each side of the house (in general there were 12 core samples) and combined for a
composite sample.
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, Table 6-16 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
78
-------
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 in Which Lead-Based Paint
Hazards Were Found
(# Homes Below Standards / # Homes)
Lead in Dust Characterized by Lead in Dust Characterized by
the Arithmetic Mean || the Maximum Value
Interim
Guidance
n j r> i Interim
Proposed Rule _ . .
Guidance
Proposed Rule
112
77.7%
52.7%
83.9%
67.0%
% of Homes in Which Lead-Based Paint Hazards Were Found Based on Media Standards
(ft of Homes Below Media Standards / # 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 (2 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
8.0%
3.9%
5.5%
27.7%
83.0%
7.6%
7.7%
0.0%
NA
19.6%
4.9%
16.5%
49.1%
NA
27.6%
NA
NA
NA
Performance Characteristics
Sensitivity
Specificity
Positive Predictive Value
Negative Predictive Value
83.3%
23.9%
23.0%
84.0%
87.5%
56.8%
35.6%
94.3%
91.7%
18.2%
23.4%
88.9%
87.5%
38.6%
28.0%
91.9%
Notes: 1. Floor, window sill, and window well samples were collected as dust wipes. Window well samples
are not included in the Proposed Rule sampling scheme. All available dust samples (wipe) taken in
the bedroom, play area, entryway, and kitchen were included in the analysis. Three core soil
samples were taken on each side of the house (in general there were 12 core samples) and
combined for a composite sample.
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.
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.
Comparing Table 6-15 to 6-16 shows that when the window well samples were included
in the testing, more homes were found to have lead-based paint hazards under the Interim
Guidance, even though the standards were lowered in the Proposed Rule. When either the
79
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arithmetic mean or maximum value are used to characterize the dust levels, the window well
samples drive the conclusion that a home has lead-based paint hazards. For example, when the
maximum value is used to characterize the dust samples, 83.9% of the homes are found to have
lead-based paint hazards under the Interim Guidance, with 83% of the homes a result of window
wells. While more homes are found to have lead-based paint hazards 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 (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 unnecessarily conclude that homes
have lead-based paint hazards.
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. 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
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, the home is found to have lead-based paint hazards.
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 medium/component is greater than its respective standard, the home is found to have
lead-based paint hazards. To understand the effect these summary methods may have, consider
Table 6-15 again.
As discussed earlier, for both sets of standards, fewer homes are found to have lead-based
paint hazards when the arithmetic mean is used to characterize the dust levels than when the
80
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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 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 hi Tables 6-10 and 6-11. Overall, Table 6-17 shows that, under the
Proposed Rule, the combination of the arithmetic mean, lower media 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.
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 in 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 estimated cost 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).
If a basic fee were charged for the risk assessment, the estimated costs of the assessments
varied slightly depending on the number of rooms (i.e., number of dust samples) in which
samples are obtained. The basic fee estimations ranged from $547.50 for a risk assessment that
had 6 dust samples taken to $584.11 when up to 9 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).
81
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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 in Which Lead-Based Paint Hazards
Were Found
(# Homes Below Standards / # Homes)
Interim Guidance*
Proposed Rule6
112
85.7%
75.9%
% of Homes in Which Lead-Based Paint Hazards Were Found Based on Media Standards
(# of Homes Below Media Standards/ # 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 (25% 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%
3 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.
Notes: 1. Floor, window sill, and window well samples were collected as dust wipes. Window well samples
are not included in the Proposed Rule sampling scheme. All available dust samples (wipe) taken in
the bedroom, play area, entryway, and kitchen were included in the analysis. Three core soil
samples were taken on each side of the house (in general there were 12 core samples) and
combined for a composite sample. Three XRF paint-lead measurements were taken from various
surfaces, and the three measurements for each surface were averaged.
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.
82
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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.
Number of Individual Samples per Home
Sampling Protocol Group A
A-1 (4 Rooms)
8-9
A-2 (3 Rooms)
7
A-3 (2 Rooms)
6
Estimated Cost of Activity
Basic Fee
Separate Fee
$584.11
$814.00
$561.50
$814.00
$547.50
$814.00
Notes: 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 5-2 for definitions of sampling protocols A-1, A-2, and A-3.
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 cost
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)
C-2
(Lead Hazard Screen)
Estimated Costs of Activity
Basic Fee
Separate Fee
$584.11
$814.00
$126.00
$575.25
Notes: 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.
As expected, the estimated costs of a lead hazard screen were less than 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.
83
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6.2 OBJECTIVE 2: ABILITY OF ESTIMATORS AND SAMPLING PROTOCOLS TO
DETERMINE TRUE AVERAGE LEAD LEVELS
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.
Presented below are
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
4. A discussion of the effect the different media/component standards, Interim
Guidance and Proposed Rule, have on 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. The components of variation were
calculated using log-transformed dust-lead loadings and soil-lead concentrations. Because some
of the estimates were calculated in previous EPA work, the source from which the estimates were
extracted is also provided.
84
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Table 6-20. Estimated Within-House Components of Variation1 for Each Data Source,
Medium, and Component.
Data Source
Rochester
Study
CAP Study
Rhode Island
Depart-
ment of
Health
Data
Medium
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 (a,2)
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)
1 The components of variation were calculated with log-transformed dust-lead loadings and soil-lead
concentrations
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
study window well variance component is nearly double the Rhode Island data window well
variance component. The combined side of house/foundation soil component of variation for the
Rhode Island data soil is larger than either the foundation or boundary soil variation seen for the
CAP Study data.
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
assesses 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.
85
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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 the error probabilities were calculated
under the Interim Guidance standards and the within-house variation from the Rochester Study
and CAP Study data were used. Figures 6-8 and 6-9 present the same 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 (false positive) and Type n (false negative) 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 jig/ft2 for window wells. For a lead hazard screen under the Interim
Guidance, the dust standards are 50 ng/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 (false positive) error probabilities (i.e., incorrectly concluding that
lead-based paint hazards exist) and to the right are the Type n (false negative) error probabilities
(i.e., incorrectly concluding that no lead-based paint hazards exist). 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.
86
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to oo too in 140 ito
C~m*ltm KMI [tot UU l~4b| (t«/ltX) oo HMO
• Iu<> «t TB»
900 400 MO
d Ibu On* l~d
M 000 000 1000 UOO 1400
• GMwtoto *-» «•* UU UWfe| (•t/IU) — Ibtew ¥
-------
bnr FroboMUtr onr • bn«o ol Trno Condition
(tataf loll SU»d»i4. 9000 ppm
Houoo Oomotrk llou Soil U»d Craconlnlloo (ppn) on 'ouodiUoo
r PnboMlHr onr • Euto el Tru» (Tonrtlttom
IMnf Soil SUiuUnt WOO p
HntM Coomolrlo MUD Soil Uo4 ConoonlnUon (ppm) 01 tVnmoVtoo
bnr Prab^llUr enr • lu<« g< Tnu C
Ciu.lit» K~» SMI Uwl Cnmotnlln (ppo) ••
Irrar ProboMlUy onr • koafo of Truo
U«m« SoU Sludard. 6000 ppm
(Tkno mxumuteo SoU Suapla)
0 1000 BOO 3000 4000 6000 6000 1000 (000 6000 10000
Hogoo Coomotrlo kUoi SoU Lot* ConoootnUog (ppm) on
brar PntabUUr onr • but* •> Tnu ODdltlou
P«ta< loll Sluduil. MOO ppm
(Tour rnuuUUon SOU Suipta)
btlmoion: Goomotrie HMa
0 1000 SOOO 3000 4000 5000 1000 1000 6000 MOO 10000
Hoiao Cooootito Uou Soil Uod ConooDtratloa (pprn) o>
Iiror ProbobUUr onr • IUKO of Tnu CoDdlUou
UdW Sou SUixUnl 9000 ppm
(Pour Bouulutoi Son Suipta)
btlnuUrr Goomotrto Ibu
0 1000 6000 3000 4000 6000 6000 1000 6000 6000 10900
HOOT (hoOMtrtellou SoU I-^CoaoooJroUoa(pfa)Mloiart.rt«o ____
Figure 6-7. Comparison of Risk Assessment Geometric Mean, Arithmetic Mean, and
Maximum Value Error Probabilities for Two. Three, and Four Soil Samples
Using the Interim Guidance Standards - Variance Components from the
Foundation of the Home and Boundary of the Property in the CAP Study Data.
88
-------
Udii Ftooo Bmt Bit
40 « M 100 UO 140 110
Tnu Unuo Cctnrtilo X«u Dint tud Uo41u (of/fit) «n Floor.
Ctnr PnWbllUr >nr • JUnj. ol Tni« CradUln*
0 10 40 00 60 100 ISO 140 110 ISO BIO
TruHoiuoCooiiiilile Hun Dull l~dLoo4ln<(ii«/IU)nno«ri
tha lUuw OwmMito Ibu P«* U«d LovUi^ (m/IU) on Ibdow im>
bnr PnbabilUr vnr • Ru«« of Triu C«odtti«u
UiJaf fflndov nflji Diut LMd H«Mrd Scnra Sludvd
biM BBUM C«om*Uto HMA Diul U^ Loufliic (u Ihnl L~4 Huutl Scnni SluuUrt
(TvoSuaplM)
no 400 wo •» looo urn
truo Homo Coomolftc Ibu Diut U>4 U*dta( (n/fia) on
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.
89
-------
Error Probability ov«r * R*n«* of Tru» Condition*
U.ln, Soil 3t.nd.rd, oOOO ppm
(Two Foundation Soil Sample*)
1OOO 8000
Hou*« G
30OO 4OOO 6OOO OOOO 7OOO OOOO OOOO 1OOOO
trio U*an Soil L*ad Concentration (ppm) on Foundation
Error Probability ov«r • R^n«« of Tru« Condition*
U«in« Soil Standard. OOOO ppm
(Tnr«« Foundation Soil Smmplmm)
1OOO BOOO
HOUMM C«
3000 4000 0000 aooo TOOO aooo oooo 10000
am«trlo M«*n Soil L«.d Cono*ntr*tion (ppm) on Foundation
Error Probability ov«r « R«n«« of Truw Condition*
Ualnc Soil St*nd«rd. OOOO ppm
(Four Foundmtion Soil 9»mpl«a)
1OOO 3OOO 3OOO 4OOO 6OOO 6OOO TOOO SOOO OOOO 1OOOO
Kotui* O«ozn*trla Ummn Soil L^.d Cona«ntr*Uon (ppm) on Foundation
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.
90
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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
fc/g/ft2)
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 (False Positive) Error
Arithmetic
Mean
0.140
0.530
,
0.150
0.623
.
0.150
0.712
,
0.237
0.598
.
0.231
0.660
t
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
•
Type II (False Negative) Error
Arithmetic
Mean
t
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
The floor dust wipe standard at which a home is found to have lead-based paint hazards was assumed to be
100 jt/g/ft2 for the risk assessment and 50 fjglft.2 for the lead hazard screen.
91
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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
(z/a/ft»)
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 (False Positive) 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 (False Negative) 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 is found to have lead-based paint hazards was
assumed to be 500 /yg/ft2 for the risk assessment.
92
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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
0/g/ft*)
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 I (False Positive) 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 (False Negative) 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
The window well dust wipe standard at which a home is found to have lead-based paint hazards
assumed to be 800 ^g/ft2 for the risk assessment and 400 j/g/ft2 for the lead hazard screen.
was
93
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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 (False Positive) 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 (False Negative) 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 is found to have lead-based paint hazards was assumed to be
5,000 ppm.
As the assumed "true" average lead level moves further from the standard of comparison,
the Type I (false positive) and Type II (false negative) error probabilities, for all three statistics,
approach zero. The geometric mean always produces the lowest Type I (false positive) error
probabilities, while the maximum value produces the highest Type I (false positive) error
probabilities. The reverse is true for Type II (false negative) errors. The error probabilities for
94
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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:
1. Type I (false positive) 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)
2. Both Type I (false positive) and Type II (false negative) error rates were high (usually
over 0.250) for all three statistics when the "true" media lead level was 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 (false positive) error rates were 0.33,0.42, and 0.65,
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 be found to have
lead-based paint hazards when the true house lead level is actually below the standard, but fewer
homes will be found to have no lead-based paint hazards 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
be found to have lead-based paint hazards when the true house lead level is below the standard,
but more homes will be found to have no lead-based paint hazards when the true lead level is
above or equal to the standard. If the extreme differences in the Type I (false positive) and
Type n (false negative) 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.
95
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6.2.2.2 "Simple" Lead Hazard Screen
Only Type I (false positive) 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 was incorrectly found to have lead-based paint hazards based on the media
standards, but whether a home was incorrectly found to have lead-based paint hazards based on a
lead hazard screen. This precludes Type n (false negative) 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.
Since a risk assessor must perform a full risk assessment when a home is found to have
lead-based paint hazards based on the lead hazard screen, the Type I (false positive) 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 jig/ft2, i.e., below the hazard screen Interim Guidance cut-off of 50
ug/ft2. The probability of incorrectly finding lead-based paint hazards in 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 the lead hazard screen will find lead-based paint hazards, forcing additional testing through
a full risk assessment even though the true lead levels were below the standard. This high error
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
determining that no lead-based paint hazards exist in the home if another estimator had been 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.
96
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Error Probability onr • Italic* »< Tru* Condition*
U*tn( Floor* Du*t Lull Huard Somn aUBiUrd
(Two (tempi**)
10 eo 30 40 BO eo TO oo
True Koui* C.om.trtc Hun Du*l L**d Loading (m/ltE) on noon
Error Probability onr • Ran** of Tru* CondlUou
UUn( Wlndov 8UU Du.t Uul lUxvd Somn StuuUrd
(Two 3*mpl«i)
1OO ZOO 3OO 400
Tru* HOUBB Ottomvtrlo ftteaa Duat La«d Loadlni (uf/tt£) on Window 8U1*
Error Probabllllr oror • IUnc« of Tru* Condition*
Urine Window W«U* Du*t Lwd Huard Ser**n SUndud
(Two Sampl**)
1.0
O.B
O.B
O.T'
o.a
0.9
0.4
0.3
O.B
0.1
0.0
• Oomitrio M**n
• Arithmetic lUmn
100 BOO 300 400 IOO BOO 700
Tnu Hoiu* G*om*trto U.M Du.t U*d Lo«dlnl (ui/tta) OB Window W*U*
BOO
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.
97
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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.
Location
Floors
Window
Sills
Window Wells
Number of
Samples
2
3
4
2
3
4
2
3
Assumed
"True" House
Dust Lead
Loading (j/g/ft*)
30
50
70
100
30
50
70
100
30
50
70
100
100
250
400
500
100
250
400
500
100
250
400
500
200
400
600
800
200
400
600
800
200
400
600
800
Type
Under the
Geometric
Mean
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
(False Positive) Error Probability
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
0.495
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 Qft5
The floor dust wipe standard at which a home is found to have lead-based paint hazards was assumed to
be 50//g/ftJ and the window well dust wipe standard at which a home is found to have lead-based paint
hazards was assumed to be 400 i/g/ft2.
98
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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.
Table 6-26 presents a summary of the Type I (false positive) error probabilities as the
number of samples increases, under the Interim Guidance standards using 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, when the true average window sill dust-lead loading
is assumed to be 250 ug/ft2 (i.e., half the standard), the Type I (false positive) 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,
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 (false positive) and Type II (false negative) error probabilities.
In general, across all media and data sets, as the number of samples increases the Type I
(false positive) 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 (false positive) 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 II (false negative) error probabilities all
decrease as the number of samples increases for all three statistics.
99
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Table 6-26.
Summary of the Type I (False Positive) 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|/fl/ft»)
Window Sill Dust
(250A/fl/ft'}
Window Well Dust
(400//0/ft»)
Soil (Boundary)
(2500/yg/e)
Number of Somples
2
3
4
2
3
4
2
3
4
2
3
4
Type < (False Positive) 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
6.2.4 Effect of the Interim Guidance and Proposed Rule Standards on the Error
Probabilities
To assess the impact that the Proposed Rule reduced dust and soil standards have on the
Type I (false positive) and Type II (false negative) error probabilities, consider Tables 6-27 and
6-28, which present summaries of the Type I (false positive) and Type II (false negative) 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. (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.)
In general, lowering the standards as in the Proposed Rule may lower the probability of a
wrong decision. For discussion of this point, ignore the fact that the Proposed Rule requires the
arithmetic mean for floor dust, window sill dust, and soil samples, and compare the Type n (false
negative) maximum value error probability shown in Table 6-28, when four samples are
100
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Table 6-27. Summary of Type I (False Positive) 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
Du»t
Soil
(Foundation)
Number
of
Room*
2
3
4
2
3
4
2
3
4
Assumed
Tru*"
HOUM L«ad
Uval
uvo/ft2)
26
60
26
60
25
60
100
260
100
260
100
250
1,000
2,000
1,000
2,000
1,000
2,000
Type 1 (Falsa Positive) 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
0.050
Geometric
Mean
0.002
0,144
0.001
0.096
0.000
0.066
0,023
0,196
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
0.276
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
0.698
0.231
0.660
0.206
0.730
0.249
0.610
0.239
0.681
0.202
0.763
0.173
0.687
0.165
0.646
0.132
0,709
Geometric
Mean
0.144
0.500
0.096
0.500
0.066
0.600
0.128
0.500
0.082
0.500
0.054
0.600
0.103
0.500
0.061
0.500
0.037
0.600
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
0.661
0.938
101
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Table 6-28.
Summary of Type II (False Negative) 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
U/fl/ft2)
150
750
6,000
Type II (False Negative) Error
Interim Guidance
Arithmetic
Mean
0.216
0.148
0.073
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
•C0.001
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.001. This illustrates a
reduction in the chances of incorrectly concluding that a home has no lead-based paint hazards
when it in fact does. 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
finding lead-based paint hazards in a home is 0.275, while the Proposed Rule Type I (false
positive) error probability is 0.641. This illustrates a large increase in the chances of incorrectly
concluding that a home has lead-based paint hazards when the home does not. Therefore, the
Proposed Rule standards, when using a maximum value, have decreased the chances of
incorrectly concluding that no lead-based paint hazards exist, but have increased the chances of
incorrectly concluding that lead-based paint hazards do exist.
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
102
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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 ug/ft2, the Interim Guidance Type n (false
negative) error is still 0.012, but the Proposed Rule Type II (false negative) 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 (false positive) 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 finding no lead-based paint
hazards in a home when it should have and moderate decreases in the chances of incorrectly
finding lead-based paint hazards in a home when it should not have. 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: SAMPLING LOCATIONS RISK ASSESSORS MAY WANT TO
TARGET TO EVALUATE POTENTIAL LEAD HAZARDS
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 need 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 for 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
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
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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 bg-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 were 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 hi 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.
These results indicate that a 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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Bedroom Window
Well Quit
I
Bedroom Window
Sill Oust
Ptiy Ana Window
Sill Dutt
I
Pley Aret Window
Wall Dutt
Bedroom Floor Oust
BLOOD
Interior Entrywiy
Floor Dutt
P1»V Aree Floor Dutt
Figure 6-11. Statistically Significant Pathways of Lead Exposure Using the
Rochester Study Data.
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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 changing from 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 hazard. The
Objective 1 analysis used performance characteristics, while the Objective 2 analysis used error
probabilities. Table 7-1 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.
Performance Characteristics
Sensitivity: P(Y 2 S | B 2 10 fjg/dl)
Specificity: P(Y < S | B < 10/yg/dL)
PPV: PIB* 10jug/dL | Y 2 S)
NPV: P(B < 10;/g/dL | Y < S)
Error Probability
Type I (False Positive) Error:
Type II (False Negative) Error:
P(Y * S | u
P(Y < S | fj
< S)
28)
Note: Y = Calculated lead level in the home for component/media/statistic
S = Standard for the component/media
B = Child's blood lead concentration
fj = 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 identifying lead hazards 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." [25] 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 those for the
pathways analysis conducted hi 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 to ensure the best evaluation of the
potential lead hazard to a child. In this analysis, floor dust and 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 ulterior entryway floor dust-lead. These results may
recommend that a risk assessor sample dust from the floor in a child's play area to gain an
understanding of the potential hazard to a child. This is consistent with the intent of the Interim
Guidance, the HUD Guidelines, and the Proposed Rule. In addition, since 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,
the removal of requirements for sampling from the window well, andjthe 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. (1973) Nonparametric Statistical Methods, Wiley Press.
[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," Federal Register, pp. 47248-47257, September 11,1995.
[5] U.S. Environmental Protection Agency (1996) "Lead: Requirements for Lead-Based
Paint Activities in Target Housing and Child-Occupied Facilities, Final Rule," 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 (1995) "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.
[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 n." 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] Centers for Disease Control (1997) Erratum published hi Morbidity and Mortality Weekly
Report, Vol. 46, No. 26, p. 607, July 4,1997.
[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.
[11] 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.
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[13] Bornschein, 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] Bornschein, R.L., Succop, P.A., Kraffl, 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] Bornschein, R.L., Clark, C.S., Grote, I, 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, edd., 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.
(1998) "Components of Variation of Lead in Household Dust, Soil, and Paint," Peer
Review Draft prepared by Battelle for the Office of Pollution Prevention and Toxics, U.S.
Environmental Protection Agency, EPA Contract Number 68-D5-0008, June 10,1998.
[19] A Lead-Based Paint Risk Assessment Model Curriculum (1995) prepared for the U.S.
Environmental Protection Agency, Chemical Management Division.
[20] U.S. Environmental Protection Agency (1998) "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 (1996) "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 (1996) "Final Report for the Comprehensive
Abatement Performance Study Volume H: Summary Report," Office of Prevention,
Pesticides, and Toxic Substances, U.S. Environmental Protection Agency. EPA 230-R-
94-013b, April 1996.
[23] U.S. Environmental Protection Agency (1997) "Risk Analysis to Support Standards for
Lead in Paint, Dust, and Soil," Office of Pollution Prevention and Toxics, U.S.
Environmental Protection Agency. EPA 747-R-97-006, December 1997.
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[24] Lanphear, B.P., Matte, T.D., Rogers, J., Clickner, R.P., Dietz, B., Bornschein, R.L.,
Succop, P., Mahaffey, K.R., Dixon, S., Galke, W., Rabinowitz, M., Farfel, M., Rohde, C.,
Schwartz, J., Ashley, P. and Jacobs, D.E. (1998). "The Contribution of Lead-
Contaminated House Dust and Residential Soil to Children's Blood Lead Levels."
Environmental Research 79:51-68.
[25] Hartford, P.A., Nagaraja, J. (1999) "Analysis of Pathways of Residential Lead Exposure
in Children," Final Draft Report prepared by Battelle for the Office of Pollution
Prevention and Toxics, U.S. Environmental Protection Agency, EPA Contract Number
68-D5-0008, June 1999.
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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 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.
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
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.
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(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 (f) 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
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
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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) Ail 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
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.
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(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)
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.
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(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 detectr ble 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.
(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.
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(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
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
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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.
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
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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 " ? med 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
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, cornerboards, 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.
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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 (EEL) 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.
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.
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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.
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.
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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 a'-eas, 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.
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 hi 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.
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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.
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.
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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 thne 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 HA. 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,
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
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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
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 hi Section 745.227 of today's final
rule, such as sampling methodologies and visual inspection techniques, refer to guidance. As a
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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.
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 rule 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
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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.
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
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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.
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
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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
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
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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
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' Vhole 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
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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.
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
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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.
1. 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
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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
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
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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 conductLig 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,
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.
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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
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
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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 VI. A. 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
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.
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As discussed earlier in Unit Vn.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
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
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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 JoU 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
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
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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 ug/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 B-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
Curriculum [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 hi 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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Table B-1. Purpose, Scope, and Consequences of an Inspection, Lead Hazard Screen, Risk Assessment, Risk Assessment/
Inspection and EBL Investigation
Inspection
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
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) Chipped 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 ENVIRONMENTAL 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 (pig/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 ng/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 mmimum):
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 fig/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.
B-13
-------
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.)
B-14
-------
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.
B-15
-------
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 B-2 for a comparison of
the lead hazard screen with a full risk assessment and a paint inspection.
B-16
-------
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.
B-17
-------
Table B-2. Comparison of a Lead Hazard Screen, a Risk Assessment, and a Paint Inspection
Component
Visual Inspection
Paint
Dust
Soil
Water
Air
Paint Guidance Level
Oust Guidance Level
Soil guidance Level
Housing Condition
Use Patterns
Assessment
Management and
maintenance data
Lead Hazard Screen
Yes
Deteriorated Paint Only
2 Composite
1. Floor (entryway) 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
play area, and additional location
No
No
No
1 .0 mg/cm2 or 5,000 ppm or 0.5%
floors = 50//g/ft2
window troughs = 400 //g/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 = 100//g/ft2
window sills = 500 fjglH2
window troughs = 800 //g/ft2
400 fjg/g high contact
2,000 fjg/g residential yard
5,000 fjg/g permanent abatement
Yes
Yes
Optional - depends on property type
Paint Inspection
Yes
Surface-by-Surface
Optional
Optional
Optional
No
1 .0 mg/cm2 or 5,000 ppm or
0.5%
Same as risk assessment if
conducted
Same as risk assessment if
conducted
Not Required
No
No
00
-------
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.
B-19
-------
B6.0 REFERENCES
[ 1 ] Lead-Based Paint Risk Assessment Model Curriculum" prepared by the U.S.
Environmental Protection Agency, Chemical Management Division, 1995.
[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.
B-20
-------
APPENDIX C
Risk Assessor Cost Questionnaire
C-1
-------
-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: I I I
7.P-I I I I I LI I Q
CONTACT PERSON:
POSITION:
TELEPHONE NUMBER
:(l I I l)l I I LI I I I lext.
GREETING
Hello, my name is
and I'm calling from the Battelle Memorial Institute in Columbus,
Ohio. We are doing a study with the Environmental Protection Agency to assess the capacity of the Section 402I*;.:':'
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:
C-2
-------
-3-
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 {Gotoquestion81} 78% (n=9)
A2. Do you have different consultation fees for
different expected activities?
YES 0%(n=2)
NO {Goto question 81} 100% (n=2)
A3. What are your consultation fees for a:
a. Risk Assessment
b. Lead Hazard Screen
c. Inspection
d. Risk Assessment/
Inspection
C-3
-------
-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?
a. Basic Fee 44% (n=g)
{Go to question 82}
b. Separate Fees for each activity ... 56% (n=9)
{Go to question 810}
BASIC FEE INFORMATION
B2. What is your basic fee for a
risk assessment?
$422.50 (n=4) ($190-$900)
B3. a. Is there a Visual Inspection
included in the Basic Fee?
Yes
No
100%(n=4)
0% (n=4)
{Go to B4)
b. What is the additional fee to
perform a Visual Inspection?
B4. a. Is a Risk Assessment Report
included in the Basic Fee?
Yes
No
100%(n=4)
0% (n=4)
{Go to 85}
b. What is the additional fee for the
Risk Assessment Report?
B5. Is Environmental Sampling
included in the Basic Fee?
Yes 50%(n=4) ... {Goto86}
No 50% (n=4) ... {Go to Sty
C-4
-------
-5-
p PIILL RISK ASSESSMENT (Continued)
B5 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
i. Water
Location
c. Floor
d. Window Sill
e. Window Well
Type of Sample or
Method of Collection (Check)
EH Scoop
L~H Single Samples
[D Composite Samples
O Single Samples
LJ Composite Samples
Gl Single Samples
Q Composite Samples
LJ Single Samples
CH Composite Samples
f. XRF
g. Paint Chips - Single Samples
h. Paint Chips - Composite
Samples
No. of Samples
Collected
3 (n=1) (3-3)
• (n=0) (•-•)
6 (n=2) (5-8)
• (n=0) (•-•)
• (n=0) (•-•)
• (n=0) (•-•)
• (n=0) (•-•)
• (n=0) (•-•)
• (n=0) (•-•)
• (n=0) (•-•)
225 (n=1) (200-250)
• (n=0) (•-•)
• (n=0) (•-•)
• (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
No
100% (n=2) {GotoB8}
0% (n=2) {Goto C1}
C-5
-------
-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
•
-------
-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)
0(n=1)
(3-8)
2(n=2)
(1-4)
• (n=0)
(•-')
<(n=0)
(•-•)
• (n=0)
(...)
1 (n=1)
(1-1)
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)
($15-$15)
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)
Total Cost of
Environmental
Samples
$100(n=2)
($45-$200)
$150(n=1)
($75-$200)
$42.50 (n=2)
($15-$120)
• (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)
$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
811. A Risk Assessment Report
B12. Typical Environmental Sampling
$272 (n=5) ($150-$500)
$282 (n=5) ($504500)
$260(n=5) ($41.50-31000)
C-7
-------
-8-
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-*)
• (n=0)
(•-•)
• (n=0)
(...)
• (n=0)
(...)
1 (n=1)
(1-1)
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)
($15-$15)
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)
Total Cost of
Environmental
Samples
$100(n=2)
($45-$200)
$150(n=1)
($75-$200)
$42.50 (n=2)
($15-$120)
• (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)
$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) ($150-3500)
$282 (n=5) ($50-$500)
$260 (n=5) ($41.50-$1000)
C-8
-------
-9-
B. FULL RISK ASSESSMENT (Continued)
B15. What are the incremental costs?
Medium
Type of Sample
Collection
Cost Per
Sample
Analysis Cost/
Sample
Total Cost per
Environmental
Samples
a. Single
(n=0)
Dust
$21.50(n=5)
($15-$30)
b. Composite
(n=0)
• (n=0)
(...)
$21.50(n=5)
($15-$30)
• (n=0)
(...)
Soil
c. Composite
(n=0)
$20 (n=3)
($15=$25)
$20 (n=3)
($15-$25)
d. XRF
(n=0)
(n=0)
Paint
e. Paint Chips - Single Samples
(n=0)
$20.58 (n=3)
($16.50-$25)
f. Paint Chips - Composite Samples
(n=0)
(n=0)
• (n=0)
(...)
$20.58 (n=3)
($16.50-$25)
• (n=0)
(...)
g. Water
(n=0)
$15(n=1)
($15-$15)
$15(n=1)
($15-$ 15)
h. Other Optional Samples
(COMPLETED SECTION B — GO TO QUESTION C1)
C-9
-------
-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 100% (n=5)
Fee? No 0% (n=5)
{Go to 04}
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?
(n=0) (• -
C5. Is Environmental Sampling
included in the Basic Fee?
Yes
No
100% (n=5)
0% (n=5)
{Go to 06}
{Go to 09}
C-10
-------
-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)
d Single Samples
l_| Composite Samples
B Single Samples
Composite Samples
ED Single Samples
LJ Composite Samples
ED Composite Samples
e. XRF
f. Paint Chips - Single Samples
g. Paint Chips - Composite Samples
No. of Samples
9 (n=1)
• (n=0)
(8-10)
(•-•)
• (n=0) (•-•)
• (n=0) (•-•)
• (n=0)
• (n=0)
2(n=1)
(._.)
(._.)
(1-2)
10 (n=1) (10-10)
• (n=0) (•-•)
• (n=0) (• - •)
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
incremental costs for each additional sample?
Yes
No
20% (n=5) (Goto C8}
80% (n=5) {Goto D1}
C-11
-------
-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)
(._.)
• (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)
C-12
-------
-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=2)($150-$200)
$200(n=2)($150-$250)
$200.25 (n=2) ($175.50-8225)
C-13
-------
-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)
($18.50-$25)
• (n=0)
(...)
Total Cost per
Environmental
Samples
$120 (n=1)
($120-$120)
$50(n=1)
($50-$50)
• (n=0)
(...)
$122.63 (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)
($50-3120)
Paint: Varies depending on home circumstance.
C14. If more environmental samples are
required do you have incremental costs
for each additional sample?
Yes
No
100% (n=2)
0% (n=2)
{Go to C15}
. {Go to 01}
C-14
-------
-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-$2S)
• (n=0)
(._.)
Total Cost per
Environmental
Samples
$20(n=1)
($20-$20)
$25(n=1)
($25-$25)
• (n=0)
(•-•)
$21.75(n=2)
($18.50-$25)
- (n=0)
(•-•)
f. Other 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)
C-15
-------
-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 02}
b. Separate Fees for each activity ... 33% (n=9)
{Go to question D10}
BASIC FEE INFORMATION
D2. What is your basic fee for
an Inspection?
$300 (n=6) ($125-$600)
D3. a. Is there a Visual Inspection included in the
Basic Fee?
Yes
No
100%(n=9)
0%(n=9)
{GotoD4}
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) {Goto05}
17% (n=6)
b. What is the additional fee for the
Risk Assessment Report?
D5. Is Environmental Sampling included
in the Basic Fee?
Yes
No
83% (n=6) {Goto 06}
17%(n=6) {Go to 09}
C-16
-------
-17-
n 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)?
D7.
Medium
Paint
Dust
Soil
Water
d. Other Optional Samples
Dust: 3-4 where children play.
Paint: As many as needed.
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)
As necessitated, usually 10.
For modest 3 bedroom, 200-250 reading.
If more samples are required, do you have Yes A
incremental costs for each additional No 6
0% (n=5) fGc
0% (n=5) /Go
sample?
to D8}
toE1}
C-17
-------
-18-
D. INSPECTION (Continued)
D8. 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
Collection
Cost Per
Sample
• (n=0)
(•-•)
• (n=0)
(._.)
•(n=0)
(._.)
Analysis
Cost/
Sample
•(n=0)
(...)
•(n=0)
(...)
• (n=0)
(...)
Total Cost Per
Environmental
Samples
• (n=0)
(...)
• (n=0)
(...)
•(n=0)
(...)
d. Other Optional Samples
Dust
Soil
Water
•(n=0)
(._.)
•(n=0)
(•-•)
•(n=0)
(...)
$10 (n=2)
($5-$15)
$15(n=1)
($15-$15)
$15(n=1)
($15-$15)
$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)
C-18
-------
-19-
p. INSPECTION (Continued)
09. 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-$750)
$380 (n=2) ($260-$500)
$348.67 (n=3) ($18.50-$750)
C-19
-------
-20-
D. INSPECTION (Continued)
D13. What are the individual environmental sampling costs for
Medium
Type of Sample
No. of
Samples
Collection
Cost Per
Sample
Analysis Cost/
Sample
Total Cost per
Environmental
Samples
Paint
Surface-by-
Surface
a. XRF
(n=0)
•(n=0)
(n=0)
b. Paint Chips - Single
Samples
35.83 (n=3)
(15-50)
(n=0)
$20.67 (n=3)
($18.50-$25)
(n=0)
$727.92 (n=3)
($277.50-$925)
c. Other Optional Samples
Paint Surface-bv-Surface: Varies depending on home circumstances.
D14. If more environmental samples are
required do you have incremental costs
for each additional sample?
Yes
No
100%(n=3)
0% (n=3)
{Goto 015}
. {GotoEl}
C-20
-------
21-
p. INSPECTION (Continued)
015. 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-$25)
$20.67 (n=3)
($18.50-525)
c. Other Optional Samples
(COMPLETED SECTION D — GO TO QUESTION E1)
C-21
-------
-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 £3}
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) {Goto£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
No
100% (n=5)
0%(n=5)
{Go to £6}
b. What is the additional fee for the
Risk Assessment Report?
E6. Is Environmental Sampling
included in the Basic Fee?
Yes ....... 80% (n=5) {GotoET}
No 20% (n=5) {Goto£10)
C-22
-------
-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)
LJ Composite
LJ Single Samples
Q Composite Samples
S Single Samples
Composite Samples
LJ Single Samples
LJ Composite Samples
LJ Single Samples
LJ 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
No.
{Conclude Interview-
Go to Last Page} ..
100%(n=4)
. 0%(n=4)
C-23
-------
-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-bv-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)
C-24
-------
-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-bv-Surface: No additional fee.
1 (n=1)
(1-1)
•(n=0)
(...)
$15(n=1)
($15-$15)
$15(n=1)
($15-$15)
(COMPLETED SECTION E — CONCLUDE INTERVIEW — GO TO LAST PAGE)
SEPARATE FEE FOR EACH ACTIVITY
What is the overall cost of
E11. A Visual Assessment
E12. A Risk Assessment/
Inspection Report
E13. Typical Environmental Sampling
$650(n=3)($200-$1500)
$312.50 (n=2)($125-$500)
$694.17 (n=3) ($140-$1325)
C-25
-------
-26-
E. RISK ASSESSMENT/INSPECTION (Continued)
E14. What are the individual environmental sampling costs for
Medium
Dust
Soil
Paint Surface-
by-Surface
f. Other Options
Dust: Varies de
Paint: Varies de
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)
($277.50-$! 000)
il Samples
pending on home circumstance.
pending 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)
C-26
-------
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)
($16.50-$20)
Total Cost per
Environmental
Samples
$22.50 (n=3)
($20-$30)
• (n=0)
(._.)
• (n=0)
(._.)
• (n=0)
(•-•)
$18.38 (n=2)
($16.50-$20)
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.}
C-27
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-------
APPENDIX D
Choices for a Risk Assessor
D-1
-------
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.
D-2
-------
APPENDIX E
Blood and Environmental
Sampling Standards
E-1
-------
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 ng/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
for Section 403 Interim Guidance, and
E-2
-------
Floors * 25 ug/ft2
Window sills * 125 ug/ft2
for Section 403 Proposed Rule.
Soil The risk assessment standard for soil is s> 5000 ppm for Section 403 Interim
Guidance, and ^ 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 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.
E-3
-------
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-------
APPENDIX F
Data Set Criteria
F-1
-------
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.
F-2
-------
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).
F-3
-------
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.).
F-4
-------
APPENDIX G
Summary Tables and Figures
G-1
-------
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
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)
$15.00
$15.00- $15.00
(a)
(a)
(a)
$15.00
$15.00- $15.00
(a)
$15.00
$15.00- $15.00
Total Cost
(a)
$15.00
$15.00- $15.00
(a)
(a)
(a)
$15.00
$15.00- $15.00
(a)
$15.00
$15.00- $15.00
Number of
Samples
Collected
(b)
4.3
3-5
(b)
(b)
(b)
1
1 - 1
(b)
1
1 - 1
a No cost was reported.
The number of samples collected was not reported.
G-2
-------
Table G-2. Average Cost Per Sample and Average Number of Samples for Sampling
Performed by a Certified Risk Assessor During a Risk Assessment, Lead
Hazard Screen, Inspection, Risk Assessment/Inspection for Agency NE-2.
Media
Dust
Paint
Soil
Water
Type of Sample
Composite
Single
Paint Chips -
Composite
Paint Chips - Single
XRF
Composite
Single
Cost Per Sample {$)
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)
(a)
(a)
$10.67
$10.00- $12.00
(a)
$10.00
$10.00- $10.00
Number of
Samples
Collected
(b)
7.7
6-10
(b)
(b)
225
200 - 250
1.5
1 -2
(b)
(b)
No cost was reported.
The number of samples collected was not reported.
G-3
-------
Table G-3. Average Cost Per Sample and Average Number of Samples for Sampling
Performed by a Certified Risk Assessor During a Risk Assessment, Lead
Hazard Screen, Inspection, Risk Assessment/Inspection for Agency NE-3.
Media
Dust
Paint
Soil
Water
Type of Sample
Composite
Single
Paint Chips -
Composite
Paint Chips - Single
XRF
Composite
Single
Cost Per Sample ($)
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 - $25.00
Number of
Samples
Collected
5.5
3-8
5.5
3-8
(b)
(b)
65
65 -65
3
2-4
(b)
(b)
No cost was reported.
The number of samples collected was not reported.
G-4
-------
Table G-4. Average Cost Per Sample and Average Number of Samples for Sampling
Performed by a Certified Risk Assessor During a Risk Assessment, Lead
Hazard Screen, Inspection, Risk Assessment/Inspection for Agency NE-4.
Media
Dust
Paint
Soil
Water
Type of Sample
Composite
Single
Paint Chips -
Composite
Paint Chips - Single
XRF
Composite
Single
Cost Per Sample ($)
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 - $20.00
(a)
(a)
(a)
(a)
(a)
(a)
Number of
Samples
Collected
-------
Table G-5. Average Cost Per Sample and Average Number of Samples for Sampling
Performed by a Certified Risk Assessor During a Risk Assessment, Lead
Hazard Screen, Inspection, Risk Assessment/Inspection for Agency S-1.
Media
Dust
Paint
Soil
Water
Type of Sample
Composite
Single
Paint Chips -
Composite
Paint Chips - Single
XRF
Composite
Single
Cost Per Sample ($)
Minimum Cost - Maximum Cost
Collection Cost
(a)
(a)
(a)
(a)
(a)
(a)
(a)
(a)
Analysis Cost
(a)
$27.50
$25.00 - $30.00
(a)
(a)
(a)
(a)
(a)
(a)
Total Cost
(a)
$27.50
$25.00 - $30.00
(a)
(a)
(a)
(a)
(a)
(a)
Number of
Samples
Collected
(b)
22.5
20-25
(b)
(b)
(b)
(b)
(b)
(b)
No cost was reported.
The number of samples collected was not reported.
G-6
-------
Table G-6. Average Cost Per Sample and Average Number of Samples for Sampling
Performed by a Certified Risk Assessor During a Risk Assessment, Lead
Hazard Screen, Inspection, Risk Assessment/Inspection for Agency S-2.
Media
Dust
Paint
Soil
Water
Type of Sample
Composite
Single
Paint Chips -
Composite
Paint Chips - Single
XRF
Composite
Single
Cost Per Sample ($)
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 - $25.00
(a)
(a)
Number of
Samples
Collected
(b)
7.3
2-10
(b)
(b)
(b)
4
2-5
(b)
(b)
a No cost was reported.
The number of samples collected was not reported.
G-7
-------
Table G-7. Average Cost Per Sample and Average Number of Samples for Sampling
Performed by a Certified Risk Assessor During a Risk Assessment, Lead
Hazard Screen, Inspection, Risk Assessment/Inspection for Agency S-3.
Media
Dust
Paint
Soil
Water
Type of Sample
Composite
Single
Paint Chips -
Composite
Paint Chips - Single
XRF
Composite
Single
Cost Per Sample ($)
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 - $20.00
(a)
(a)
Number of
Samples
Collected
6
6-6
7
6-8
(b)
(b)
(b)
10
10- 10
(b)
(b)
No cost was reported.
The number of samples collected was not reported.
G-8
-------
Table G-8. Average Cost Per Sample and Average Number of Samples for Sampling
Performed by a Certified Risk Assessor During a Risk Assessment, Lead
Hazard Screen, Inspection, Risk Assessment/Inspection for Agency W-1.
Media
Dust
Paint
Soil
Water
Type of Sample
Composite
Single
Paint Chips -
Composite
Paint Chips - Single
XRF
Composite
Single
Cost Per Sample ($)
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.
The number of samples collected was not reported.
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)
(a)
(a)
$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
No cost was reported.
The number of samples collected was not reported.
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 Dust Samples per
Home
% of Homes in Which Lead-Based Paint
Hazards Were Found
(# Homes Below Standards / # Homes)
% of Blood Samples ;> 1 0 jjg/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 in Which Lead-Based Paint Hazards Were Found Based on Media Standards
(# of Homes Below Media Standards / # 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)
81. 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)
21.7% (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)
21.7% (18/83)
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%)
Notes: 1. For 2, 3, and 4 rooms, respectively, 6, 7, and 8-9 dust wipe samples were obtained from floors,
window sills, and window wells. Three core soil samples were taken on each side of the house (in
general there were 12 core samples) and combined for a composite sample. Three XRF paint-lead
measurements were taken from various surfaces, and the three measurements for each surface
were averaged.
2. See Table 5-3 for definitions of sampling protocols A-1, A-2, and A-3.
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 Dust Samples per
Home
% of Homes in Which Lead-Based Paint
Hazards Were Found
(# Homes Below Standards / # Homes)
% of Blood Samples * 10//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 in Which Lead-Based Paint Hazards Were Found Based on Media Standards
(# of Homes Below Media Standards / # 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)
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
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%)
Notes: 1. For 2, 3, and 4 rooms, respectively, 6, 7, and 8-9 dust wipe samples were obtained from floors and
window sills. Window well samples are not included in the Proposed Rule sampling scheme. Three
core soil samples were taken on each side of the house (in general there were 12 core samples) and
combined for a composite sample. Three XRF paint-lead measurements were taken from various
surfaces, and the three measurements for each surface were averaged.
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.
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).
# Homes Included in Analysis
Number of Individual Dust Samples /
Homes
% of Homes in Which Lead-Based Paint
Hazards Were Found
(# Homes Below Standards / # Homes)
% of Blood Samples z 10//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 in Which Lead-Based Paint Hazards Were Found Based on Media Standards
(# of Homes Below Media Standards / # 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
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
Performance Characteristics
Sensitivity
(LCB, UCB)
Specificity
(LCB, UCB)
Positive Predictive Value
(LCB, 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%)
Notes: 1. For 2, 3, and 4 rooms, respectively, 6, 7, and 8-9 dust wipe samples were obtained from floors,
window sills, and window wells.
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.
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).
# Homes Included in Analysis
Number of Individual Dust Samples /
Homes
% of Homes in Which Lead-Based Paint
Hazards Were Found
(# Homes Below Standards / # Homes)
% of Blood Samples ;> 10 ywg/dL
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 in Which Lead-Based Paint Hazards Were Found Based on Media Standards
(# of Homes Below Media Standards / # 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
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
Performance Characteristics
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%)
58.8%
(32.9%, 81.6%)
77.3%
(65.3%, 86.7%)
40.0%
(21.1%, 61.3%)
87.9%
(76.7%, 95.0%)
Notes: 1. For 2, 3, and 4 rooms, respectively, 6, 7, and 8-9 dust wipe samples were obtained from floors
and window sills. Window well samples are not included in the Proposed Rule sampling scheme.
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.
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 in Which Lead-Based Paint
Hazards Were Found
(# Homes Below Standards / # Homes)
% of Blood Samples 2 10//g/dL
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 in Which Lead-Based Paint Hazards Were Found Based on Media Standards
(# of Homes Below Media Standards / # Homes in Which Samples Were Collected)
All Floors
Carpeted Floors Only
Uncarpeted Floors Only
Window Sill
Window Well
Soil
Oripline Soil Only
Play Area Soil Only
Paint (> 15% deteriorated paint)
1.8% (2/112)
0.0% (0/102)
1.8% (2/1 09)
16.1% (18/112)
67.9% (76/112)
7.6% (8/105)
7.7% (8/104)
0.0% (0/52)
88.4% (38/44)
3.6% (4/112)
1.0% (1/102)
2.8% (3/109)
22.3% (25/112)
75.9% (85/112)
7.6% (8/105)
7.7% (8/104)
0.0% (0/52)
88.4% (38/44)
8.0% (9/112)
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% (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%)
91.7%
(73.0%, 99.0%)
17.0%
(9.9%, 26.6%)
23.2%
(15.1%, 32.9%)
88.2%
(63.6%, 98.5%)
Notes: 1. Floor, window sill, and window well samples were collected as dust wipes. All available dust
samples (wipe) taken in the bedroom, play area, entryway, and kitchen were included in the
analysis. Three core soil samples were taken on each side of the house (in general there were 12
core samples) and combined for a composite sample. Three XRF paint-lead measurements were
taken from various surfaces, and the three measurements for each surface were averaged.
2. See Table 5-3 for definitions of sampling protocols A-1, A-2, and A-3.
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 in Which Lead-Based Paint
Hazards Were Found
(# Homes Below Standards / # Homes)
% of Blood Samples * 10/vg/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 in Which Lead-Based Paint Hazards Were Found Based on Media Standards
(# of Homes Below Media Standards / # 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% (6/112)
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)
27.6% (29/105)
27.6% (29/105)
NA
NA
88.4% (38/43)
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%)
87.5%
(67.6%, 97.3%)
35.2%
(25.3%, 46.1%)
26.9%
(17.5%, 38.2%)
91.2%
(76.3%, 98.1%)
Notes: 1. Floor and window sill samples were collected as dust wipes. Window well samples are not
included in the Proposed Rule sampling scheme. All available dust samples (Wipe) taken in the
bedroom, play area, entryway, and kitchen were included in the analysis. Three core soil samples
were taken on each side of the house (in general there were 12 core samples) and combined for a
composite sample. Three XRF paint-lead measurements were taken from various surfaces, and
the three measurements for each surface were averaged.
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.
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 in Which Lead-Based Paint
Hazards Were Found
(# Homes Below Standards / # Homes)
% of Blood Samples * 1 0 /yg/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 in Which Lead-Based Paint Hazards Were Found Based on Media Standards
(# of Homes Below Media Standards / # 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% (2/109)
16.1% (18/112)
67.9% (76/112)
3.6% (4/112)
1% (1/102)
2.8% (3/109)
22.3% (25/112)
75.9% (85/112)
8% (9/112)
3.9% (4/102)
5.5% (6/109)
27.7% (31/112)
83% (93/112)
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%)
Notes: 1. Floor, window sill, and window well samples were collected as dust wipes. All available dust
samples (wipe) taken in the bedroom, play area, entryway, and kitchen were included in the
analysis.
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.
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).
# Homes Included in Analysis
% of Homes in Which Lead-Based Paint
Hazards Were Found
(# Homes Below Standards / # Homes)
% of Blood Samples ;> 1 0 //g/dL
Sampling Protocol Group B
B-1
(Geometric Mean)
112
31.3%
B-2
(Arithmetic Mean)
112
35.7%
B-3
(Maximum Value)
112
57.1%
21.4%
% of Homes in Which Lead-Based Paint Hazards Were Found Based on Media Standards
(# of Homes Below Media Standards / # 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
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%)
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%)
Notes: 1. Floor and window sill samples were collected as dust wipes. Window well samples are not
included in the Proposed Rule sampling scheme. All available dust samples (wipe) taken in the
bedroom, play area, entryway, and kitchen were included in the analysis.
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.
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).
# Homes Included in Analysis
% of Homes in Which Lead-Based Paint Hazards
Were Found
(# Homes Below Standards / # Homes)
% of Blood Samples 2 1 0 /yg/dL
Sampling Protocol Group C
C-1
(Risk Assessment)
112
84.8%
C-2
(Lead Hazard Screen)
112
83.0%
21.4%
% of Homes in Which Lead-Based Paint Hazards Were Found Based on Media Standards
(# of Homes Below Media Standards / # 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)
8.0% (9/112)
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)
88.4% (38/43)
8.9% (10/112)
2.9% (3/102)
7.3% (8/109)
NA
82.1% (92/112)
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)
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%)
Notes: 1. Floor, window sill, and window well samples were collected as dust wipes. All available dust
samples (wipe) taken in the bedroom, play area, entryway, and kitchen were included in the analysis.
Three core soil samples were taken on each side of the house (in general there were 12 core
samples) and combined for a composite sample. Three XRF paint-lead measurements were taken
from various surfaces, and the three measurements for each surface were averaged.
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.
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 in Which Lead-Based Paint
Hazards Were Found
(# Homes Below Standards / # Homes)
% of Blood Samples i 1 0 fJQ/dl
Sampling Protocol Group C
C-1
(Risk Assessment)
112
59.8%
C-2
(Lead Hazard Screen)
112
44.6%
21.4%
% of Homes in Which Lead-Based Paint Hazards Were Found Based on Media Standards
(# of Homes Below Media Standards / # 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)
8.9% (10/112)
2.9% (3/102)
7.3% (8/109)
32.1% (36/112)
NA
27.6% (29/105)
NA
NA
88.4% (38/43)
30.4% (34/112)
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%)
Notes: 1. Floor and window sill samples were collected as dust wipes. Window well samples are not included
in the Proposed rule sampling scheme. All available dust samples (wipe) taken in the bedroom, play
area, entryway, and kitchen were included in the analysis. Three core soil samples were taken on
each side of the house (in general there were 12 core samples) and combined for a composite
sample. Three XRF paint-lead measurements were taken from various surfaces, and the three
measurements for each surface were averaged.
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.
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 in Which Lead-Based Paint
Hazards Were Found
(# Homes Below Standards / # Homes)
% of Blood Samples z 1 0 //g/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 in Which Lead-Based Paint Hazards Were Found Based on Media Standards
(# of Homes Below Media Standards / # 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% (2/109)
16.1% (18/112)
3.6% (4/112)
1% (1/102)
2.8% (3/109)
22.3% (25/112)
8% (9/112)
3.9% (4/102)
5.5% (6/109)
27.7% (31/112)
NA
7.6% (8/105)
7.7% (8/104)
0% (0/52)
7.6% (8/105)
7.7% (8/104)
0% (0/52)
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%)
Notes: 1. Floor and window sill samples were collected as dust wipes. All available dust samples (wipe)
taken in the bedroom, play area, entryway, and kitchen were included in the analysis. Three
core soil samples were taken on each side of the house (in general there were 12 core
samples) and combined for a composite 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.
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).
# Homes Included in Analysis
% of Homes in Which Lead-Based Paint
Hazards Were Found
(# Homes Below Standards / # Homes)
% of Blood Samples :> 1 0 fjg/dl
Sampling Protocol Group B
B-1
(Geometric Mean)
112
48.2%
B-2
(Arithmetic Mean)
112
52.7%
B-3
(Maximum Value)
112
67.0%
21.4%
% of Homes in Which Lead-Based Paint Hazards Were Found Based on Media Standards
(# of Homes Below Media Standards / # 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)
27.6% (29/105)
27.6% (29/105)
NA
NA
NA
Performance Characteristics
Sensitivity
(LCB, UCB)
Specificity
(LCB%, UCB)
Positive Predictive Value
(LCB%, UCB)
Negative Predictive Value
(LCB%, UCB)
79.2%
(57.8%, 92.9%)
60.2%
(49.2%, 70.5%)
35.2%
(22.7%, 49.4%)
91.4%
(81.0%, 97.1%)
87.5%
(67.6%, 97.3%)
56.8%
(45.8%, 67.3%)
35.6%
(23.6%, 49.1%)
94.3%
(84.3%, 98.8%)
87.5%
(67.6%, 97.3%)
38.6%
(28.4%, 49.6%)
28.0%
(18.2%, 39.6%)
91.9%
(78.1%, 98.3%)
Notes: 1. Floor and window sill samples were collected as dust wipes. Window well samples are not
included in the Proposed Rule sampling scheme. All available dust samples (wipe) taken in the
bedroom, play area, entryway, and kitchen were included in the analysis. Three core soil
samples were taken on each side of the house (in general there were 12 core samples) and
combined for a composite 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.
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 in Which Lead-Based Paint
Hazards Were Found
(# Homes Below Standards / # Homes)
% of Blood Samples i 10/;g/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 in Which Lead-Based Paint Hazards Were Found Based on Media Standards
(# of Homes Below Media Standards / # 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% (2/109)
16.1% (18/112)
67.9% (76/112)
7.6% (8/105)
7.7% (8/104)
0% (0/52)
3.6% (4/112)
1% (1/102)
2.8% (3/109)
22.3% (25/112)
75.9% (85/112)
7.6% (8/105)
7.7% (8/104)
0% (0/52)
8% (9/112)
3.9% (4/102)
5.5% (6/109)
27.7% (31/112)
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%)
Notes: 1. Floor, window sill, and window well samples were collected as dust wipes. All available dust
samples (wipe) taken in the bedroom, play area, entryway, and kitchen were included in the
analysis. Three core soil samples were taken on each side of the house (in general there were
12 core samples) and combined for a composite 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.
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 in Which Lead-Based Paint
Hazards Were Found
(# Homes Below Standards / # Homes)
% of Blood Samples * 10//g/dL
Sampling Protocol Group C (Lead Hazard Screen)
Interim Guidance
112
83.9%
Proposed Rule
112
67.0%
21.4%
% of Homes in Which Lead-Based Paint Hazards Were Found Based on Media Standards
(# of Homes Below Media Standards / # Homes in Which Samples Were Collected)
All Floors
Carpeted Floors Only
Uncarpeted Floors Only
Window Sill
Window Well
Soil
Oripline Soil Only
Play Area Soil Only
Paint U 5% deteriorated)
8.9% (10/112)
2.9% (3/102)
7.3% (8/109)
NA
82.1 (92/112)
NA
NA
NA
77.3% (68/88)
30.4% (34/1 1 2)
10.8% (11/102)
26.6% (29/109)
64.3% (72/112)
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%)
Notes: 1. Floor, window sill, and window well samples were collected as dust wipes. All available dust
samples (wipe) taken in the bedroom, play area, entryway, and kitchen were included in the
analysis. Three XRF paint-lead measurements were taken from various surfaces, and the three
measurements for each surface were averaged.
2. NA indicates that these samples were not included in the analysis.
G-24
-------
APPENDIX H
Summary Error Probability Tables and Graphs
for the Interim Guidance Standards
H-1
-------
40 « ao m in tw in
Tnw RMM Cmutrto Item Dart Lud leUlaf (ui/fll) w
100 UO 140 1*0
M I^d LM
-------
Imr PrtbaUlif mx • B«af« •! Tnu f^r^Klmt
Udat noon Out Bttt iMOTw
(Twluptoi)
40 go ao 100 in 140 i«o
Tnn H«u> boButrio Ibu Dint Iwd LoUlaj (ut/rtf) n Finn
brar rntaUlllr «nr • lu|« «f T
ut l~d Huu4
(Tourlunpto)
U>
M
OJ
0.7
OJ
0.5
0.4
OJ
40 00 M 100 UO 140 100
Tru H»UM C«om.lrto Hun Durt Uul Uw41a« (u|/fU) ea Ftoo™
bnr PnbvbUllr nw • 8«aj« *f AIM
Udm Itidn Ui Dint B*
Irilhmrtlcltou
100I00900400HOOOOTOOOOO
TRu Htiu. 0«m>liio Ibu Dul Ud LMdlif (m/IU) « n>dn 9Ult
bnr PntaWUr «nr • lUao «t Thu CndlUnu
OUnj (lido* ffib DuM lad Huu4 Senu 9lu( (uj/fU) a
• lu|> ol Ira«
00 400
TmtHouM
000 000 1000 UOO 1400
lUu Durt 1—4 U«Ua« fa/IU) a Ito4m WtBi
n 400 ooo ooo low u
TDM Hou~ CMtnrtito Ibu Dwt Ud lo^itaf (x/U) «a I
Figure H-2. 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 Rochester Lead-in-Dust
Study Data.
H-3
-------
bnr PntaMUtj
• But* rt TVw CBattUM*
40
Tn. B
M «0 100 1M 140 110
d—owlrle Kua Diut Lu4 b«d!a| (m/M) w rtem
r PnteUUjr am ft Ku|« of tnM
0 IOOtOOJ00400MO«»TOO«00«00 1000
Tnu Hm» C~»«tn» Ibu Dirt L>d lM
-------
40 to to 100 ta iu in
Tn» Bran CMHtrk feu, Out UM Uutla* (n/IU) • flnn
40 • 10 100 UO 140
Till Hi in -liiinliln If-in Itial !••< I 1ln| (nl'r'1 -
IMaC Ibrfav BUh Dart lUk AM
> *> tn» CudlUw
04
OJ
0.1
u
400 100 MO 109
tow tail LM* UW1« (««/m) «. »
mr > lup g) 1M CMXtUu*
I"
U
U
0.1
rrm • linf! W TTM f
" 111 Tin" --'" r'
*00 100 ION 1100
Ibu DMl 1—<
MO logo u
l Irrt lirr"-| (^/T*l i- '
141
• Mb
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.
H-5
-------
I
l.O
o.e
O.8
O.T
o.e
0.5
O.4
O.3
O.E
O.I
O.O
Estimator*:
Error Probability over a Range of True Condition*
Ualng Floor* Duet Lead Hazard Screen Standard
(Three Sample*)
Geometric Mean
Arithmetic Mean
Maximum
ZO 3O 4O BO OO "TO BO
True Houee Geonaetric Mean Du*t Lead Loading (ug/ftZ) on Ploora
1OO
Error Probability ov«r a Rang* of True Condition*
living Window Sill* Du«t L*>ad Hazard Ser**n Standard
(Tnr«« 3ampl««)
l.O
O.B.
o.e-
O.T-
Evtlmator*:
O.3-
o.e-
o.i
o.o
Geometrlo Mean
• - Arithmetic Mean
Maximum
1OO ZOO 3OO 4OO
True Houee Geometrlo Mean Duvt Lead Loading (ug/ft2) on Wlndovr SUle
Error Probability over a Range of True Condition*
Blng Window Well* Du*t Lead Havard Screen Standard
(Tnree Sample*)
O.D
O.O
O.T
O.O
O.O
O.4
O.3
0.2
0.1
O.O
E*tlmator*:
Gvomatrie M«an
Arithm«tio U«an
------ Maximum
1OO ZOO 3OO 4OO SOO BOO
True Hou*e Geometrlo Mean Duet Lead Loading (ug/ftZ) on Wlndo
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.
H-6
-------
Error Probability ovar a Ranga of Trua Condition.
U.lng Floor. Duat Laad Hazard Soraan Standard
(Four Sampl..)
l.O
o.e-
o.o
O.7
o.e
0.8
o.«
o.a
O.B
o.i
o.o
C.timator.:
Gaomatrto Maan
Arlthmatle Uaan
Maximum
SO 3O 4O BO BO TO
Trua Hou.a Gaomatrie Mean Du.t L«oid Loading (ug/ft&)
ao
k Floor.
Error Probability ov.r a RonB> of Tru« CondlUon.
Window Sill. Du.t L«ad Hazard 3or.«n Standard
(Four Sampla.)
l.O
0.9
O.B
O.T
o.a
O.B-
O.4
o.a-
o.e-
o.i
o.o
E.tlmator
Q«om«trio Uvan
Arithmetic U.an
Uaximum
1OO ZOO 3OO «OO
Trua Hou.a Gaomatrio llaan Ouat Laad Loading (ug/ftS) on Window ailla
Error Probability ovar a anga of Trua Condition.
U.ing Window Walla Du.t Laad Haxard Soraan Standard
(Four Sampla.)
BOO aoo 400 BOO aoo TOO
Trua Hou.a Caomatrio Maan Du«t Laad Loading (ug/ttZ) on Window Walla
BOO
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.
H-7
-------
Error Probability ov.r a Ranga of True Condition"
Ualna Floor* Dual Laad Hazard Seraan Standard
(Two Saznplaa)
l.O-
o.e •
o o
O.7-
o.e
S o.o
o.
O.3-
o.z-
O.I •
0.0
Eatlmatora:
Gaomatrlo Maan
Artthmatlc Uaan
Maximum
SO 3O «O 6O BO TO
Tru* Houav Gvomatrie Maan Du»t L«ad Loading (uc/ftS)
SO
n Floor*
Error Probability over a Rang* of Tru« Condition*
/•ing Window Sill* Du«t L«ad Hazard Soraan Standard
(Two Samp la •)
l.O
o.e
o.a
O.T
o.o
o.a
o.«
0.3
o.z
O.I
o.o
Evtlmator*:
^^^^~ Gaomatrlo Maan
Arlthmatlo Uaan
1OO ZOO 3OO 4OO
Trua Hou*a Gaomatrla Uaan Duat Laad Loading (uff/fte) on Wlndoir SUla
U>in« Window Walla Duat l^aad Hazard Scraan Standard
(Tiro Samplaa)
1OO ZOO 3OO 4OO SOO BOO TOO
Tru* Hou»« Gaomatrlo Mean Dual Laad Loading (u»/ft2) on Window Walla
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.
H-8
-------
Error Probability over a Rang* of True Conditions
Uelnc Iloora Duet Load Hazard Screen Standard
(Three Sample*)
1.0
O.B
O.B
O.T-
o.a
O.B
O.4-
O.3-
o.e-
0.1
O.O
Eetlmatore:
Geometric Mean
Arithmetic Moan
• Maximum
BO 3O 4O BO BO TO 8O
Tru« HOUM Oconutrie Waul Du.t L»d Loadloc
-------
or Probability ovar a Ranga of Trua Condition.
U.lna Floor. Du»t Lead Hazard Soraan Standard
(rour Bamplaa)
1.0-
O.9
O.B
O.7
O.B
0.0
0.4
O.3
0.8
0.1
0.0-
Eatlraatora:
Gaomatrlo Uaan
• Arlthmatlc Maa
Maximum
eo 30 40 BO eo 70 BO
Trua Houaa Gaomatrlo Mean Duct Laad Loading (ug/ftZ) on Floora
1.0
o.e
o.a
O.7
o.a
o.e
0.4
0.3-
O.a -
O.I •
O.O-
Error Probability ovar a Ranga of Trua Conditions
U.lng window Sill. Du.t Laad Haiard Soraan Standard
(Four Samplaa)
Gaomatrlo Maan
• Arlthmatlo liaan
Maaslmuro
1OO ZOO 3OO 4OO
Trua Houaa Oaomatrlo Uaan Duat Laad Loadlna (us/fte) on Window ailla
Error Probability ovar a Ranga of Trua Conditions
alna Window Walla Dust Laad Hasard Scraan Standard
(Four Samplaa)
l.O
o.e
O.B
O.7
O.B
O.O
O.4
0.3
0.2
0.1
O.O
Estimator*:
—^— Gaomatrlo Uaan
• Arithmetic Maan
Majelmuna
1OO ZOO 3OO 4OO BOO
Trua Houaa Gaomatrlo Maan Du.t Laad Loadlnc (u«/ft2)
BOO
on 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.
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
(A/g/ft1)
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 (False Positive) 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 (False Negative) 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 is found to have lead-based paint hazards was assumed
to be 100;/g/fta for the risk assessment and 50^g/ft2 for the lead hazard screen.
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
"True"
House
Window Sill
Dust Lead
Loading
(A/g/ft*)
250
500
1,000
250
500
1,000
250
500
1,000
250
500
1,000
250 i
500
1,000
250
500
1,000
Error Probability of the Statistic
Type 1 (False Positive) Error
Arithmeti
c 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
•
Geometr!
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 (False Negative) 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 is found to have lead-based paint hazards was
assumed to be 500 //g/ft2 for the risk assessment.
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
U/g/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 (False Positive) Error
Arithmetic
Mean
0.245
0.490
.
0.303
0.629
.
0.307
0.720
.
0.385
0.584
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 (False Negative) 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 is found to have lead-based paint hazards was
assumed to be 800 jug/ft* for the risk assessment and 400^g/fta for the lead hazard screen.
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
(ppm)
2,500
5,000
7,500
2,500
5,000
7,500
2,500
5,000
7,500
Error Probability of the Statistic
Type I (False Positive) 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 (False Negative) 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 is found to have lead-based paint hazards was assumed to be
5,000 ppm.
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
(//g/ft»)
30
50
70
100
30
50
70
100
30
50
70
100
100
250
400
500
100
250
400
500
100
250
400
500
200
400
600
800
200
400
600
800
200
400
600
800
Type 1 (False Positive) 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 is found to have lead-based paint hazards was assumed to be 50 //g/ft*
and the window well dust wipe standard at which a home is found to have lead-based paint hazards was assumed to be
H-15
-------
This page intentionally left blank
-------
APPENDIX I
Summary Error Probability Tables and Graphs
for the Proposed Rule Standards
1-1
-------
tenl U («|/IU)
bnr PntaMDIr mr • lup el Dm CndUkv
Udu Fbon M Ud BiMrt Icnv 8U>du4 • (n«/IU)
bUDutarc OmriikHiu
ioB904ouMnnnioo
Tni» How GMMbfe HMD Doit UU tMdbi (x/RI) OB fVon
U
Of
O.T
t
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OJ
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, . I • • I • I . I
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tr»«goi»»Cii»ii>rUII
) 00 900 990 400
n rmn i Tit '-iiini tn."T) — ——— —-
Mil Ibd» «Bi D«rt Ui4 8u
0 SO 100 190 (00
• I • ' ' ' I I I ' • I
900 SSO 400 490 MO
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.
1-2
-------
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Urini noon Dvnt Bik loinmuil SUadird U (ni/nz)
3040SOI0708010100
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tmc PratabOltr mr • Uop ol Inn CooJHkrm
Ml| noon Diut Lud Hiurd 3cnn SluuUri Z3 (^/M)
' I ' ' ' ' I ' ' ' ' I '
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Imr PreUWMj onr > lu|i of tmi OndlUooi
uni tinii BI> lamiinni Tiiiiiiii ii nil tm/nt)
(ThnoSunpUi)
bUnlonc GoomtMc lUw
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• I I I I I 11 »I • I • • I • I I I I I I • I • I I I I I I I I I I
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Trao BOOM CoonoUb Ihu Dart Uo4 Uidll| («|/M) on Ibdm Sto
bnr FnUbUUjr onr • lu|> ol Tnn CoodUbu
0«n, Ibdow Sill Dint IM! Buud 9crom JUutart 1Z3 (t«/nt)
I-
i-
••*•* ArithmeticKou
U lHOIMK)Ot50»0»0*004S0500
Tn» Bourn Grantee Kou Dut Uod Uodlai («»/IU) on ItoomSUli
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.
1-3
-------
UBm Flood 8ml till •
• lu|> ri Dm
tO
U
U
a?
g 0.1
1"
„
U
U
0.1
CwwUfetbu
Tn» Bou» CwivMc Una Dot It* U»dl^ (n/IU) m Floon
bnr PnMdUr mr • bi(< ri fti»
IMai Ftoon Dmt iMd
n9040SO«TDIOWIOO
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r «nr • Bu|i « tai CtadUbu
IMai Halo. 9Ub Dart Bik bMmat Sludlrt 250 (of/nZ)
(rcurlunpb.)
M 100 ISO H» 00 300 » 400 440
Tm B«ai CrauWe Hiu tat I«4 Indlai (ni/IU) n IWnr 9Bb
bnr PratabOU; onr > lup ol Ttw OndUliM
Uril| Ibdow SUb Diut Uvl Buud Scram SUndud 119 (uj/IU)
0.1
OJO
• • I • I I I I I 1 I I I • I I 11 I
0 JOIOOIMIOOB03003604004SO
tn» Bran GmMlric Ibu Dint Imd U»tta| (m/M)«Itofcw 90b
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.
1-4
-------
'-— *—*-"'"r *—r -1— --«K1
tu,, nafw mam Out i—d luu^ taoi
(IMlMfh.)
M 100 IK BO
900 9H 400
(H^U)-«
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.
1-5
-------
r cnr • lu|t •( Tn> CndlUwi
Dtoi noon Dial IfckbMmmlSUadirt 50 ta/IU)
1.0
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0.7
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' ' I I ' ' I I I ' • ' I ' '
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ftmr PretaWIUy «m • lu|l ol Tn» CooOIUoM
(Mi| n>en Duit iHd Buud &na Studu4 B (B|/tU)
Mliulan:
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' ' I ' ' ' ' I • • ' ' i ' • ' ' I ' '
10Z03040MM70MM100
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fcw PretabUUy our • tup ol Tn» CouliUau
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• • I • • • • I i • i i I • • • • I i
90 100 150 TO Z50 300 350 400 460
Tn» Bra> Coonttllo Nou Dial I«d lMdb| («|/M) oo Itodow 30k
Figure 1-5. 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 Rhode Island Department of Health
Homes.
1-6
-------
. -
ML, Km, ft* fck [
ll.niliU 80 fo/IU)
w
Bmi dmlik UNI Dot bri kxktl* («/)u)« ton
bnr PrataMItr »nr • Uofi 4 In* C^OOm
IMn| Ftom Dot [Md baid Sena iludvd a («/AI)
30 40 80 •) 70 K>
• GMBrtifa Ibu Dal In4 b*4a| (u|/ft2) M Fltcn
IT-
U-
I"
0.4
04
OJ
0.1
U
90 100!JOnOBOJOOJS04004SOWO
trrm tnUOUj *i*t > tufi rf Inn C
U*K IMov SUli Pol l«d Buutf 9cna SUotord IB (t«/IU)
U
0.7
"
90 100 ISO tOO OJ 300 SSO 400
tr» B*m CMBrtrte Hw Dart twl I~dh« (>|/IU) OB Iteta. 9Db
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.
1-7
-------
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(Tw tadilto* Ml Bu»rb»)
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100 1000
tgoo 3000 3wo woo
• Ml |M< Ommnlln (n^ •• •naJutal
OJ
OJ
0.7
01
looo looo noo noo 3000
bnr PntaMtty *tw • IUB«« «f TTIM
Drill Ml §U»d«I<. 1000 pfB
trur m' — *-)]-—;•—i
HO 1000 1100
*MU
'I I'
3000 JMO 4000
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.
1-8
-------
Error Probability o-rmr a Bane* ot True Condition*
U»lnc Soil Standard. 8OOO ppra
(Two Foundation Boll Saroplaa)
BOO 1000 isoo aooo eaoo 3000 3000
Houaa Oaomatrlo Maan Soil Load Concentration (ppm) on Foundation
Error Probability ovar a Ranga of Trua Condltlona
U>ln« Soil Standard. 2OOO ppm
(Thraa Foundation Soil Samplav)
BOO 1OOO IBOO BOOO ZOOO 3OOO 3OOO
Hou»a Gaomatrlo Uaan Soil Load Conoantratlon Cppm) on Foundation
ir Probability ovar a Banco of Trua Condltlona
Ualnc Soil Standard. BOOO ppm
(Four Foundation Soil Saraplaa)
EiUmatora: Caomatrlo Ua
— — ArlUunatlo Ma
BOO 1OOO IBOO BOOO BBOO 3OOO 3BOO
Houia Oaomatrlo >
-------
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.
Assessment
"Compound
Lead Hazard
Screen
Risk
Assessment
Number
of
Samples
2
3
4
2
3
4
Assumed
"True"
House Floor
Dust Lead
Loading
U/fl/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 (False Positive) 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
.
Type II (False Negative) 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 The floor dust wipe standard at which a home is found to have lead-based paint hazards was assumed
to be 50//g/ft2 for the risk assessment and 25 ^g/ft2 for the lead hazard screen.
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
vvg/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 (False Positive) 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 (False Negative) 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 is found to have lead-based paint hazards was
assumed to be
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/ft2)
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 (False Positive) 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 (False Negative) 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 is found to have lead-based paint hazards was assumed to
be 50 /yg/ft2 for the risk assessment and 25 /yg/ft2 for the lead hazard screen.
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
•True-
House
Window Sill
Dust Lead
Loading
(pg/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 (False Positive) 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 (False Negative) 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
1 The window sill dust wipe standard at which a home is found to have lead-based paint hazards was
assumed to be 250 ^g/ft2.
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 I (False Positive) 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 (False Negative) 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
1 The soil standard at which a home is found to have lead-based paint hazards was assumed to be
2,000 ppm.
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 (False Positive) 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 (False Negative) 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 is found to have lead-based paint hazards was assumed to be
2,000 ppm.
1-15
-------
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-------
APPENDIX J
Summary of the Pathways Analysis
for the Rochester Lead-in-Dust Study Data
J-1
-------
Table J-1. Correlation Coefficients for Natural Log Transformed Dust-Lead Loadings and Blood-Lead
Concentrations from the Rochester Study.
LNBLDPB
LINTLD
LBBDLD
LPLYLD
LKITLD
LLIVLD
LKITHNLD
LLIVHSLD
LBBONSLD
LNBLDPB
LINTLD
Ln Inc. Entry Load
LBBDLD
Ln BedRoon load
LPLYLD
Ln Play Area Load
LKITLD
Ln Kitchen Load
LLIVLD
Ln Living Boon Load
LKITNHLD
Ln Kitchen H.Nell
Load
LBBDNNLD
Ln Bed Room w.Nell
Load
LPLYNHLD
Ln Play Area H.Nell
Load
LLIVNSLD
Ln Living Boon N.Sill
Load
LBRDHSLO
Ln Bed Room N.Sill
Load
LPLYNSLD
Ln Play Area N.Sill
Load
Notes:
i.ooooo
0.0
205
0.29692
0.0001
179
0.22046
0.0019
197
0.31972
0.0001
192
0.28670
0.0001
203
0.2C216
0.0977
41
0.31198
0.0006
lie
0.30129
0.0002
ISO
0.196SS
0.0209
138
0.31113
0.0884
31
0.33405
0.0001
163
0.31387
0.0001
164
1.
2.
0.29692
0.0001
179
1.00000
0.0
179
0.43618
0.0001
17S
0.39098
0.0001
170
0.52370
0.0001
178
O.SS006
O.OOOS
36
0.30116
0.0020
103
0.32466
0.0001
132
0.22018
0.0157
120
0.28263
0.1710
25
0.31077
0.0002
144
0.36873
0.0001
147
0.22046
0.0019
197
0.43618
0.0001
175
1.00000
0.0
197
0.50611
0.0001
186
0.41732
0.0001
197
0.69073
0.0001
38
0.35582
0.0001
116
0.19089
0.0206
147
0.26935
0.0018
132
0.23455
0.2296
28
0.42564
0.0001
161
0.41119
0.0001
158
0.31972
0.0001
192
0.39098
0.0001
170
0.50611
0.0001
186
1.00000
0.0
192
0.48193
0.0001
190
0.21499
0.2149
35
0.37727
0.0001
113
0.29311
0.0004
141
0.13605
0.1170
134
0.13244
0.5190
26
0.48608
0.0001
153
0.36902
0.0001
161
0.28870
0.0001
203
0.52370
0.0001
178
0.41732
0.0001
197
0.48193
0.0001
190
1.00000
0.0
203
0.17950
0.2615
41
0.18648
0.0441
117
0.35039
0.0001
149
0.21S64
0.0114
137
0.27899
0.1285
31
0.42466
0.0001
162
0.23745
0.0023
163
0.26216
0.0977
41
0.55006
O.OOOS
36
0.69073
0.0001
38
0.21499
0.2149
35
0.17950
0.2615
41
1.00000
0.0
41
0.42S62
O.OS44
21
0.40S43
0.03S9
27
0.45656
0.0249
24
0.17586
0.3615
29
0.51409
0.0043
29
0.62851
0.0002
30
0.31198
0.0006
118
0.30116
0.0020
103
0.35582
0.0001
116
0.37727
0.0001
113
0.18648
0.0441
117
0.42562
0.0544
21
1.00000
0.0
118
O.S0022
0.0001
90
0.64668
0.0001
87
O.S2990
0.0237
18
0.41809
0.0001
95
0.44325
0.0001
100
0.30129
0.0002
150
0.32466
0.0001
132
0.19089
0.0206
147
0.29311
0.0004
141
0.35039
0.0001
149
0.40543
0.0359
27
0.50022
0.0001
90
1.00000
0.0
ISO
0.48584
0.0001
106
0.60400
0.0023
23
0.49713
0.0001
144
0.44441
0.0001
118
0.19655
0.0209
138
0.22018
0.0157
120
0.2693S
0.0018
132
0.1360S
0.1170
134
0.21564
0.0114
137
0.45656
0.0249
24
0.64668
0.0001
87
0.48584
0.0001
106
1.00000
0.0
138
O.S7280
0.0162
17
0.37726
0.0001
112
O.S84SS
0.0001
130
0.31113
0.0884
31
0.28263
0.1710
25
0.234SS
0.2296
28
0.13244
0.5190
26
0.27899
0.1285
31
0.17SB6
0.3615
29
0.52990
0.0237
18
0.60400
0.0023
23
0.57280
0.0162
17
1.00000
0.0
31
0.62346
0.0009
25
0.55943
0.0084
21
0.3340S 0.31387
0.0001 0.0001
163 164
0.31077 0.36873
0.0002 0.0001
144 147
0.42564 0.41119
0.0001 0.0001
161 158
0.48608 0.36902
0.0001 0.0001
153 161
0.42466 0.2374S
0.0001 0.0023
162 163
0.51409 0.628S1
0.0043 0.0002
29 30
0.41809 0.44325
0.0001 0.0001
95 100
0.49713 0.44441
0.0001 0.0001
144 118
.0.37726 0.58455
0.0001 0.0001
112 130
0.62346 O.SS943
0.0009 0.0084
25 21
1.00000 0.45765
0.0 0.0001
163 132
0.45765 1.00000
0.0001 0.0
132 164
Analyses were conducted on natural logarithm transformed blood- lead concentrations and dust- lead loadings.
First number is the Pearson correlation coefficient, the second number is the p-value, and the third nunber is
the nunber of observations.
-------
Table J-2. Structural Equation Modeling Results for the Rochester Study Data.
Variables
^••^Independent
Dependent ^x
Blood
Play Area Floor
Bedroom Floor
Kitchen Floor
Play Area Window
Sill
Bedroom Window
Sill
Parameter Estimates (t-value)
Play Area
Floor
0.1611*
(1.98)
-0.0050
(-0.01)
-3.9562
(-0.45)
Bedroom
Floor
-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)
R»
0.24
0.01
0.00
0.00
0.34
0.32
Notes: 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 > 1.96 or <-1.96 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.
-------
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-------
APPENDIX K
Documents Used In Obtaining
Health Department Data
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:
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
K-3
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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 man
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.
K-4
-------
{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
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 Requested
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 samolina techniaue
Importance of
Requested
Information
Very Important
Very Important
Very Important
Very Important
Moderatelv Imoortant
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.
K-6
-------
DATA REQUEST AND INFORMATION SHEET
Pre-lntervention Environmental Sampling Variables Requested
Variable Requested
Unique identifier of home that can be matched to the blood
sample(s).
Importance of
Requested Information
Very Important
Variable Name in
the Data Set*
Pre-lntervention Dust Samples
Date of dust sampling
Dust lead level
Units of reported dust lead level (i.e., (jg/ft2, ug/g, etc.}
Sampling technique {i.e., wipe, vacuum, etc.)
Sampling location {i.e., bedroom, play area, etc.)
Sampling component (i.e., carpeted floors, uncarpeted
floors, window sill, window well}
Sample type (i.e., composite or individual samples}
Lab analysis technique
Limit of detection for the lab
Very Important
Very Important
Very Important
Very Important
Very Important
Very Important
Very Important
Moderately Important
Moderately Important
Pre-lntervention Soil Samples
Date of soil sampling
Soil lead concentration
Units of reported soil lead concentration
Sampling technique {i.e., core, surface scraping, etc.}
Sample type (i.e., composite or individual samples}
Ground covering (i.e., bare, grassy, % of area covered,
etc.}
Lab analysis technique
Limit of detection for the lab
Very Important
Very Important
Very Important
Very Important
Very Important
Moderately Important
Moderately Important
Moderately Important
Pre-lntervention Paint Samples
Date of paint sampling
Paint lead levels
Units of reported paint lead levels {ppm, %, mg/cm3,
etc.}
Sampling technique {i.e., XRF, bulk scraping, etc.}
Sample type {i.e., composite or individual samples}
Sampling location {i.e., interior or exterior, bedroom,
living room, porch, etc.}
Sampling component {i.e., wall, window sill, window
well, etc.}
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
* 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.
K-7
-------
DATA REQUEST AND INFORMATION SHEET
Please indicate the format of your data: Q 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
K-8
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Table K-1. Summary of the Health Department Data.
Agency
Rhode Island
Department of
Health
Pinedas County
Health
Department
Nebraska Health
and Human
Services System
Vermont
Department of
Health
City. 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
# 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.
CO
-------
Table K-1. Summary of the Health Department Data (Continued).
Agency
Ohio Department
of Health
Missouri
Department of
Health
City, State
Columbus. OH
Jef ferson City,
MO
Data Collected
Blood
Dust
Soil
Paint
Other
Blood
Dust
Soil
Paint
Water
Description
Venous
Wipe
Composite
Mostly Drip line
XRF
NA
MA
NA
NA
XRF and Paint
NA
TiflMI FfWtH
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
f of Observations
(* Homes)
48(21)'
98 (23)
32 (20)
1842(32)
1 (1)
76.745 (30.586)
912(884)
912(884)
912(884)
912(884)
Comments
Each house has hundreds of
XRF readings but sampling
dates am 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.
3*
«dt
O
Notes: 1 This does not contain 16 observations with age missing «nd 9 observations with 'Unknown* or missing sampling method.
* There are 454 observations (109 homes) for WIPE only Dust data.
1 This does not contain 66 observations with water collection method other than 'Rush'.
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APPENDIX L
Sampling Distributions of the Statistics and
Error Probability Calculations
-------
Appendix L
Sampling Distributions of the Statistics and
Error Probability Calculations
The observed natural logarithmically transformed lead level, logCY^, was assumed to
follow a normal distribution with mean u{ and variance Oj2, i.e.,
iid ~Normal(Uj, o^2), k=l,2,..., n
where
Yfc 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:
HO: Us < log Sj
H,: Uj £ log Sj.
Under the null hypothesis, HO, the true house lead level for media i was below the media
standard, while under the alternative hypothesis, H,, the home's true lead level for media i was
above or equal to the media standard. Of interest were the probabilities of correct and incorrect
decisions based on the estimated "true" media lead level at the home. In particular, the Type I
(false positive) and Type n (false negative) error probabilities defined below.
P (Type I Error) = P(conclude H, | H0 is true)
P (Type H Error) = P(conclude H,, | H, is true)
= P(Yij
-------
YJJ observed lead level in the home for component/media i and estimator./
Sj standard for component/media i
Hi true average log lead level within home for each component/media /
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.
Then 108(00 = U10g
n
2>gYik
n
vk=i
since logO7^) iid -Normal^, of), k=l,2, ..., n.
Therefore, under the above hypotheses,
(1) given that H0: u; < log S; is true,
P(TypeIError) = P(Gj ^ S;)
= P(Z
since log(G() ~Normal(^i, Oj
where Z ~N(0, 1).
(2) given that H,: (if ^ log Sj is true,
P (Type H Error) =
= P(log(Gi)
-------
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 Uj < log S{ is true,
P(Type I Error) = P(Mj * Sj)
= l-P(Mi
-------
REPORT DOCUMENTATION PAGE
Form Approved
OMB No 0704-0188
Public reporting burden for this collection of information is estimated to averge I hour per response, including the time for reviewing instructions, searching existing data
sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other
aspect of this coltecnon of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and
Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188),
Washington, DC 20503.
1. AGENCY USE ONLY (Leave blank)
2. REPORT DATE
August 1999
3. REPORT TYPE AND DATES COVERED
Final Report
4. TITLE AND SUBTITLE
Evaluation of Section 402 Risk Analysis Protocols
6. AUTHOR(s)
P.A. Hartford, Y.L. Chou, and A. Kovacs
5. FUNDING NUMBERS
C: 68-W-99-033
68-D5-0008
7. PERFORMING ORGANIZATION NAME(s) AND ADDRESS(ES)
Battelle Memorial Institute
505 King Avenue
Columbus, Ohio 43201
8. PERFORMING ORGANIZATION
REPORT NUMBER
Not Applicable
9. iPONbORlNCi/MONITORING AGENCY NAME(S) AND ADDRESS(ES)
U.S. Environmental Protection Agency
Office of Pollution Prevention and Toxics
401 M Street SW (7401)
Washington, D.C. 20460
10. SPONSORING/MONITORING AGENCY
REPORT NUMBER
EPA 747-R-99-003
11. SUPPLEMENTARY NOTES
Other Battelle staff involved in the production of this report included B. Burkhart, J. Clark, J. Groves, J. Holt, J. Kinateder
J. Ma, J. Raudabaugh, V. Sublet, H.C. Tsai, and A. Thomas.
12.a DISTRIBUTION/AVAILABILITY STATEMENT
12b. DISTRIBUTION CODE
13. ABSTRACT (Maximum 200 words)
The overall purpose of this report is to characterize the probability of a certified risk assessor correctly identifying a
lead-based paint hazard in single family housing units when choices allowed by the Section 402 regulations are made and
when using the standards and methods prescribed in both the 403 Interim Guidance and Section 403 Proposed Rule. This
report concluded that 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 play area floors provided the best indication of the
lead hazard to a child in the Rochester study; removing the window wells (troughs) 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 403 Proposed Rule, resulted in an assessment that
provided nearly the same protection as the 403 Interim Guidance, but failed fewer homes.
14. SUBJECT TERMS
Section 402 Rule, 403 Interim Guidance, 403 Proposed Rule, Risk Assessors, Performance
Characteristic Analysis, False Positive and False Negative Error Probabilities, Pathways
Analysis, Lead in Dust and Soil, Rochester Lead-in-Dust Study, Comprehensive Abatement
Performance Study
15. NUMBER OF PAGES
291
16. PRICE CODE
17. SECURITY CLASSIFICATION
OF REPORT
Unclassified
18. SECURITY CLASSIFICATION
OF THIS PAGE
Unclassified
19. SECURITY
CLASSIFICATION
OF ABSTRACT
Unclassified
20. LIMITATION OF
ABSTRACT
NSN 7540-01-280-5500
Standard Form 298 (Rev 2-89)
Prescribed by ANSI Std. Z39-18
298-102
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