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United States Solid Waste And 21S-2001
Environmontal Protection Emergency Response • May 1,991
Agency (OS-240)
&EPA Three City
Urban Soil-Lead
Demonstration Project
Midterm Project Update
U.S. Environmental Protection Agency
Region 5, Library ''.p! -'' ^
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May 1991
Prepared by:
Dr. Ann Aschengrau, Boston University School of Public Health
Ms. Marlene Berg, EPA/OSWER/OERR
Dr. Robert Bornschein, University of Cincinnati
Ms. Merrill Brophy, Maryland Department of the Environment
Dr. Scott Clark, University of Cincinnati
Dr. Robert Elias, EPA/ORD/OHEA/ECAO
with:
Dr. Allan Marcus, Battelle Applied Statistics
Dr. Dan Paschal, Centers for Disease Control
Mr. Harold Vincent, EPA/ORD/EMSL
With Technical Support From:
Environmental Criteria and Assessment Office
Office of Health and Environmental Assessment
Office of Research and Development
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May 199
1
NOTICE
The following is an internal EPA document intended to provide a midterm update of
the Three City Urban Soil-Lead Demonstration Project. This update does not include any
initial findings and is subject to revision. Project findings will be provided in final reports
prepared individually by the Maryland Department of the Environment, the City of Boston,
and the University of Cincinnati (in conjunction with EPA) and in a presentation to be given
by EPA. This update should not be construed to represent Agency policy.
Copies of the update can be obtained from:
Superfund Docket Coordinator, OS-240
401 M Street, S.W.
Washington, D.C. 20460
or by calling the RCRA/Superfund Hot Line at 1-800-424-9346 or 703-920-9810.
Mention of trade names or commercial products in the update does not constitute
endorsement or recommendation for use.
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May 1991
TABLE OF CONTENTS
LIST OF CONTRIBUTORS vii
ABSTRACT 1
1. EXECUTIVE SUMMARY 2
1.1 Statutory History , 2
1.2 Purpose of Project 3
1.3 Purpose of the Midterm Project Update 3
1.4 Project Design 3
1.5 Timeline 4
1.6 Sampling 4
1.7 Abatement 4
1.8 Baseline Data 6
1.9 Achievements 9
1.10 Final Reports 9
2. INTRODUCTION 11
2.1 Overview and Summary 11
2.2 Organization of the Midterm Project Update 11
2.3 Project Participants 12
2.4 Lead in the Environment 12
2.5 Project Background 13
2.6 Project Timeline 13
2.7 Project Design 14
2.7.1 Project Hypotheses 14
2.7.2 Methodology 14
2.7.3 Scope 15
2.8 Protocols 15
2.9 Quality Assurance / Quality Control (QA/QC) '. 15
2.10 Description of Baseline Data 16
2.11 Final Reports 17
3. PROJECT DESIGN 18
3.1 Project Hypotheses 18
3.2 Methodology 18
3.2 Baltimore Study Design 21
3.2.1 Baltimore Project Study Areas 21
3.2.2 Baltimore Study Population 22
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3.2.3 Baltimore Data Collection and Analysis 24
3.3 Boston Study Design 24
3.3.1 Boston Study Area 25
3.3.2 Boston Study Population 25
3.3.3 Boston Data Collection and Analysis 26
3.4 Cincinnati Study Design 27
3.4.1 Cincinnati Study Area 29
3.4.2 Cincinnati Study Population 29
3.4.3 Cincinnati Data Collection and Analysis 30
4. PROJECT SCHEDULE 35
5. ABATEMENT PROCEDURES 36
5.1 Introduction 36
5.2 Baltimore 36
5.2.1 Soil-Lead Abatement Procedure 36
5.3 Boston 38
5.3.1 Soil-Lead Abatement Procedure 38
5.3.2 Interior Dust Abatement Procedure 39
5.4 Cincinnati 39
5.4.1 Soil-Lead Abatement Procedure 39
5.4.2 Interior Dust Abatement Procedure 41
5.4.3 Exterior Dust Abatement Procedure 41
6. STUDY IMPLEMENTATION AND PROBLEM RESOLUTION 42
6.1 Introduction 42
6.2 Baltimore 42
6.2.1 Recruitment of Participants 42
6.2.2 Attendance at Biological Screening Sessions in Baltimore 43 '
6.2.3 Property Owner Participation 44
6.2.4 Technical Problems Related to Stabilization and Abatement Contracts .. 45
6.2.5 Maintenance of Accurate Project Subject Data 45
6.3 Boston 46
6.3.1 Recruitment and Retention of Study Participants 46
6.3.2 Lead Contaminated Soil Disposal 47
6.3.3 Frozen Ground During Lead Contaminated Soil Abatement 48
6.4 Cincinnati 48
6.4.1 Public Relations 48
6.4.2 Recruitment of Participants 49
7. PROTOCOLS 51
IV
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8. QUALITY ASSURANCE/QUALITY CONTROL GUIDELINES FOR FIELD AND
LABORATORY PRACTICES 52
8.1 QA/QC Standards for Soil, Dust, Drinking Water, and Handwipes 52
8.1.1 Sample Collection 52
8.1.2 Analytical Methodology 52
8.1.3 Laboratory QA/QC 52
8.2 QA/QC Standards for Blood Analyses 54
8.2.1 Elements of the QA/QC System 54
8.2.2 Specimen Collection 55
8.2.3 Specimen Preservation and Shipping 55
8.2.4 Analytical Method Performance 55
8.2.5 Bench and Blind Quality Control Materials 55
8.2.6 Accuracy and Blanks 56
8.2.7 Data Integrity 57
8.3 Data Reduction, Validation, and Reporting 57
8.3.1 Maintenance of Referenced Data Sets 57
8.3.2 Data Quality 58
8.3.3 Statistical Methods 58
9. SUMMARY OF PRE-ABATEMENT DATA 59
9.1 Summary of Pre-Abatement Blood-lead Concentrations 59
9.2 Summary of Pre-Abatement Source and Pathway Data 60
BIBLIOGRAPHY 69
APPENDIX A - Protocols for Sampling and Analysis
APPENDK B - External Quality Assurance/Quality Control
APPENDIX C - City Maps
APPENDIX D - Organizational Charts
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LIST OF FIGURES AND TABLES
Figure 1-1. Urban Soil-lead Demonstration Project
Table 1-1. Project Distribution of Blood-Lead (PbB) Levels 7
Table 1-2. Project Distribution of Soil-Lead Concentrations (ug/g) 8
Table 1-3. Project Distribution of Dust-Lead Concentrations (ug/g) 8
Table 3-1. Summary of Recruitment and Retention of Participants in the Baltimore Project24
Table 3-2. Summary of Recruitment and Retention of Participants in the Boston Project. 26
Table 3-3. Summary of Recruitment and Retention of Participants in the Cincinnati
Project 30
Figure 3-1. Baltimore Project 32
Figure 3-2. Boston Project 33
Figure 3-3. Cincinnati Project 34
Table 9-1. Combined Summary of Pre-Abatement Blood Lead Concentrations 59
Table 9-2. Summary of Pre-Abatement Soil and Dust Data for the Baltimore Project . . 61
Table 9-3. Summary of Pre-Abatement Soil and Dust Data for the Boston Project 62
Table 9-4. Summary of Pre-Abatement Soil and Dust Data for the Cincinnati Project .. 63
Table 9-5. Combined Comparative Summary of Pre-Abatement Soil Concentrations. ... 64
Table 9-6. Comparative Summary of Percentiles of Soil-Lead Concentrations for all
Cities 64
Table 9-7. Summary of Pre-abatement Data for Other Sources in the Baltimore Project 65
Table 9-8. Summary of Pre-abatement Data for Other Sources in the Boston Project .. 66
Table 9-9. Summary of Pre-abatement Data for Other Sources in the Cincinnati Project 67
Table 9-10. Summary of the Status of Samples Planned, Collected, and Analyzed. 68
VI
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May 1991
LIST OF CONTRIBUTORS
Dr. Ann Aschengrau
Boston University School of
Public Health
80 East Concord Street, T-355
Boston, MA 02118
Dr. David Bellinger
The Children's Hospital
300 Longwood Avenue
Boston, MA 02115
Ms. Marlene Berg
U.S. EPA
OERR OS-200
401 M Street, SW
Washington, DC 20460
Mrs. Dawn Boyer
Lockheed Engineering & Sciences Co.
1050 E. Flamingo Road, Suite 120
Las Vegas, NV 89119
Dr. Robert Bornschein
University of Cincinnati
Department of Environmental Health
3223 Eden Avenue #56
Cincinnati, OH 45267-0056
Ms. Merrill Brophy
MDE/Lead & Soil Project
Toxic Operations Program
Maryland Department of the Environment
2500 Broening Highway
Baltimore, MD 21224
Dr. Richard Brunker
U.S. EPA Region III
Site Support Section
MD-3HW26
841 Chestnut Street
Philadelphia, PA 19107
Mr. Barry Chambers
MDE/Lead & Soil Project
Toxics Operations Branch
Maryland Department of the Environment
2500 Broening Highway
Baltimore, MD 21224
Dr. Rufus Chancy
U.S. Department of Agriculture
ARC, Building 008 BARC-West
Beltsville, MD 20705
Dr. Julian Chisolm
Kennedy Institute
707 N. Broadway
Baltimore, MD 21205
Dr. Scott Clark
University of Cincinnati
Department of Environmental Health
3223 Eden Avenue
Cincinnati, OH 45267-0056
Ms. Linda Conway-Mundew
University of Cincinnati
Department of Environmental Health
1142 Main Street
Cincinnati, OH 45210
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Dr. Robert Elias
U.S. EPA
Environmental Criteria Assessment Office
MD-52
Research Triangle Park, NC 27711
Dr. Katherine Farrell
Director, Community Health Services
Health Services Building
3 Harry S. Truman Parkway
Annapolis, MD 21401
Ms. Beverly Fletcher
U.S. EPA Region I
Environmental Services Division
60 Westview Street
Lexington, MA 02173
Ms. Barbara Gordon
Department of Health
City of Cincinnati
3101 Burnet Avenue
Cincinnati, OH 45229
Ms. JoAnn Grote
University of Cincinnati
Department of Environmental Health
1142 Main Street
Cincinnati, OH 45210
Mr. Bill Hanson
University of Cincinnati
Department of Environmental Health
1142 Main Street
Cincinnati, OH 45210
Mr. Bart Hoskins
Lead Free Kids Project
20 Church St
Boston, MA 02116
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May 1991
Mr. Ronald Jones
Boston Department of Health
and Hospitals
1010 Massachusetts Avenue
Boston, MA 02118
Dr. Boon Lira
Center for Environmental Health
and Disease Control
Maryland Department of the Environment
2500 Broening Highway
Baltimore, MD 21224
Dr. Edmond Maes
Centers for Disease Control
CEfflC/EHHE, Mail Stop F28
1600 Clifton Road
Atlanta, GA 30033
Dr. Allan Marcus
Battelle Applied Statistics
100 Park Drive
P.O. Box 13758
Research Triangle Park, NC 27709
Mr. David Mclntyre
U.S. EPA Region I
Environmental Services Division
60 Westview Street
Lexington, MA 02173
Mr. William Menrath
University of Cincinnati
Department of Environmental Health
1142 Main Street
Cincinnati, OH 45210
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Dr. Tom Matte
Lead Poisoning Prevention Branch
Centers for Disease Control
Mailstop F28
1600 Clinton Road
Atlanta, GA 30333
Dr. Un Quei Pan
University of Cincinnati
Department of Environmental Health
3223 Eden Avenue
Cincinnati, OH 45267-0056
Mr. Mike Papp
Lockheed Engineering & Sciences Co.
1050 E. Flamingo Road, Suite 120
Las Vegas, NV 89119
Dr. Dan Paschal
CEHIC/EHL F-18
Centers for Disease Control
1600 Clifton Road
Atlanta, GA 30033
Mrs, Sandy Roda
University of Cincinnati
Department of Environmental Health
3223 Eden Avenue
Cincinnati, OH 45267-0056
Ms. Julia Shea
Lead Free Kids Project
20 Church Street
Boston, MA 02116
Mr. James Simpson
Center for Disease Control
CEfflC/EHHE, Man Stop F28
1600 Clifton Road
Atlanta, GA 30333
Dr. Tom Spittler
U.S. EPA Region I
Environmental Services Division
60 Westview Street
Lexington, MA 02173
Mr. Stephen Vega
Lead Free Kids Project
20 Church Street
Boston, MA 02116
Dr. Patricia Van Leeuwen
U.S. EPA Region V
Technical Support Unit
WMD, 5HRS-TUB7
230 S. Dearborn Street
Chicago, EL 60604
Dr. Harold Vincent
U.S. EPA, EMSL-QAD
P.O. Box 93478
Las Vegas, NV 89183-3478
Ms. Nina Wampler
Lead Free Kids Project
20 Church Street
Boston, MA 02116
Dr. Michael Weitzman
University of Rochester
School of Medicine and Dentistry
Rochester General Hospital
1425 Portland Avenue
Rochester, NY 14615
Ms. Natalie Zaremba
Lead Free Kids Project
20 Church Street
Boston, MA 02116
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ABSTRACT
Section lll(b)(6) of the Superfund Amendments and Reauthorization Act (SARA) of
1986 required the U.S. Environmental Protection Agency (EPA) to conduct a "pilot program
for the removal, decontamination, or other actions with respect to lead-contaminated soil in
one to three metropolitan areas." The EPA responded in 1987 by initiating an urban soil-lead
demonstration project in the cities of Baltimore, Boston and Cincinnati. The project is being
conducted by the Maryland Department of the Environment, the City of Boston, and the
University of Cincinnati, with assistance from EPA and other agencies and institutions. The
purpose of the project is to^etcnnine^whedieriAiiiedi^
The following is a midterm project update that contains preliminary baseline data for
environmental and blood samples. As study sites in the cities were not randomly selected,
baseline data is not representative of the three cities. The update does not contain preliminary
findings or draw conclusions as data is not yet available. Information in the update is subject
to revision pending completion of the project Cities will prepare individual final reports;
Boston in early 1992, followed by Baltimore and Cincinnati later in the Spring. These
reports, plus a combined report, will be presented at a conference in the Summer of 1992.
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THREE-CITY
URBAN SOIL-LEAD DEMONSTRATION PROJECT
MIDTERM PROJECT UPDATE: May 1991
1. EXECUTIVE SUMMARY
1.1 Statutory History
Section lll(b)(6) of the Superfund Amendments and Reauthorization Act (SARA) of
1986 required the U.S. Environmental Protection Agency (EPA) to conduct a "pilot program
for the removal, decontamination, or other actions with respect to lead-contaminated soil in
one to three metropolitan areas". The EPA responded in 1987 by initiating an Urban Soil-
Lead Demonstration Project in the cities of Baltimore, Boston, and Cincinnati. The studies
are being conducted by the Maryland Department of the Environment, the City of Boston, and
the University of Cincinnati, respectively. The EPA, and a number of hospitals, academic
institutions, and government agencies have assisted in the implementation of the Project and
continue to provide technical guidance and support.
1.2 Purpose of Project
Lead in the human body, whether at high or low concentrations, temporary or long-
lasting, may result in a broad spectrum of adverse health effects. These effects, sometimes
called "lead poisoning" when severe, range from dizziness, hearing impairment, destruction of
red blood cells, and delayed cognitive behavior, to convulsions, coma, and death. While lead
poisoning can be treated, many of its developmental effects are irreversible.
Young children are the population most at risk from excessive lead exposure due to their
physiological development and their frequent contact with lead-contaminated parts of their
environment (leaded paint chips, dust, soil, etc.). Lead exposure may result from normal
outdoor play activities as well as from indoor contact with paint and contaminated dust which
may collect on carpets, floors, and furniture. The human fetus is also part of this high-risk
population; lead in the maternal bloodstream may produce toxic fetal effects including
reductions in gestational age, birth weight, and mental development (ATSDR, 1990).
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^reduction of £nvirommmaliieati^nceiitratioi^
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1.5 Timeline
Although each of the three city studies is proceeding according to its own internal
agenda, the general project schedule still serves as the common timetable. Figure 1-1
highlights the general project schedule.
1.6 Sampling
Blood samples and hand/elbow wipes, taken before and after dust/soil removal, will be
used to determine the effects of abatement. Blood samples are analyzed for PbB levels.
Hand/elbow wipes determine the amount of lead on the skin. During blood sampling, any
children found to have elevated PbB levels are referred for appropriate medical evaluation and
impacts of complete abateu»utft(^
Environmental sampling (soil, interior and exterior dust, paint and water) and analysis,
conducted in the pre-abatement phase, are conducted again following dust/soil removal. The
purpose of post-abatement environmental sampling/analysis is to ensure that any changes in
biological lead levels are, in fact, correlated with changes in environmental lead.
1.7 Abatement
The reduction in environmental lead is being accomplished by removing lea*
rnniniiiinniBiiiioil^ifiiii^ln^^ mil
interior/exterior dust The Project is using several low-technology abatement methods
including interior vacuuming and washing, and shovel/backhoe soil removal. The soil
surrounding Project houses, as well as in selected playgrounds and parks, is being removed to
a depth of six inches and replaced with non-contaminated soil Cess than ISO ppm lead) and
seed/sod, mulch, and, in some instances, crushed stone. Lead-contaminated dust is being
removed through street sweeping, interior vacuuming and washing, and, in some cases,
replacement of furniture and rugs.
So that project scientists may better understand the relative effects of soil and dust
abatement, selected study sites are undergoing complete abatement (soil and interior/exterior
dust) while others are receiving only dust or soil removal. Removal actions will be
conducted at selected residential control areas at the conclusion of the study.
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1.8 Baseline Data
To date, over 3,500 biological samples and over 25,000 environmental samples have
been collected. By project completion, approximately 8,000 biological samples and nearly
40,000 environmental samples will have been collected and analyzed. Project sites and
children were not selected randomly; they were designated based on elevated soil-lead and
PbB levels. Preliminary baseline blood analyses (see Table 1-1) indicate that
^associated ;
Preliminary baseline surface-soil (0-2 cm) analyses (see Table 1-2) have also been
conducted in all three cities. Arithmetic means of soil-lead levels at this depth ranged from
2,620 ppm in Boston, to 571 ppm in Baltimore and 505 ppm in Cincinnati.
Interior dust analyses have been conducted in Boston, while baseline dust-lead levels
from other study sites are not yet available. Dust analyses from Boston showed that dust
samples collected from around windows had higher lead levels (nearly ten times greater) than
floor dust (see Table 1-3).
Baseline data included in this update are preliminary. Some additional studies need to
be conducted to interpret data, particularly for environmental samples prior to completion of
the project.
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Table 1-1.
Project Distribution of Blood-Lead (PbB) Levels1
T ' jsg/dL
0-4.9
5-9.9
10-14.9
15-19.9
20-24.9
25-29.9
30+
Total:
Mean PbB:
^
Bostoa
NA
44
62
36
10
NA
NA
152
12.6 pg/dL
Cincinnati
22
87
59
30
13
11
3
225
11.7pg/dL
Baltimore
28
139
122
71
32
5
11
408
12.5 pg/dL
, , 'Total *'••
50
270
243
137
55
16
14
785
12.3 pg/dL
x ' Percent' ./ •
6.4%
34.4%
31.0%
17.5%
7.0%
2.0%
1.8%
100.0%
1 For its study, Boston selected children with PbB levels ranging from S pg/dL to 25 pg/dL.
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Table 1-2.
Project Distribution of Soil-Lead Concentrations
: ;>,€ii$r/:Pepth ?•
•;^^^.7--;'^
# ofSainples
Minimum
Pgfe
Arithmetic
Meaajjgfjg *—:
Maximum
- *"k ^g
Boston1
0-2 cm
13-15 cm
713
704
Not Detectable
Not Detectable
2,620
1,882
21,000
19,000
Baltimore
0-2 cm
13-15 cm
1,915
1,916
22
8
571
365
7,500
3,800
Cincinnati
0-2 cm
13-15 cm
672
655
<20
<20
505
371
23,400
15,800
'Soil eligibility criteria in Boston was a median or average soil-lead concentration of at least 1500 pg/g around
house foundations.
Table 1-3.
Project Distribution of Dust-Lead Concentrations
Boston
Floor
303
Not Detectable
2,462
80,000
Window
289
Not Detectable
21,062
220,000
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1.9 Achievements
While specific conclusions cannot be determined until the completion of the study, a
number of important goals have been achieved:
• To date, over 3,500 biological samples and over 25,000 environmental samples have
been collected (see Table 9-10).
• Soil and/or dust abatement has been completed in all study areas.
• The Project has effectively synthesized the work of the three cities into one study.
Extensive coordination and cooperation overcame many of the logistical and operational
hurdles inherent to a project of this magnitude. Activities were successfully organized
among the parties conducting the studies, the EPA, several other government agencies,
and a number of academic institutions.
• Environmental sampling and analysis protocols were developed for several media.
Sampling protocols included soil, interior house dust, exterior dust, and handwipes. An
X-Ray Fluorescence (XRF) protocol was designed for soil-lead analysis.
• Detailed questionnaires were developed and used to conduct behavioral and dietary
intake surveys of the study population.
1.10 Final Reports
Study conclusions will be presented in individual final city reports scheduled for
completion by Spring 1992. These and the final combined report will be presented at a
symposium planned for Summer 1992.
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2. INTRODUCTION
2.1 Overview and Summary
In 1987, the U.S. Environmental Protection Agency (EPA) launched the Urban Soil-Lead
Demonstration Project ("Project") to implement Section lll(b)(6) of the Superfund
Amendments and Reauthorization Act (SARA) of 1986, which required EPA to conduct a
"pilot program for the removal, decontamination, or other actions with respect to lead-
contaminated soil in one to three different metropolitan areas". The three participating cities
("Participants") are Baltimore, Boston and Cincinnati. One institution in each city is serving
as a primary Project manager: the Maryland Department of the Environment, the City of
Boston, and the University of Cincinnati. EPA is coordinating their efforts.
The Project's objective is to determine whether a reduction of environmental lead
concentrations will result in decreased blood-lead (PbB) levels in children. Environmental
monitoring is used to determine the levels of lead in soil, dust, and other media. All three
cities are conducting low-technology abatement of lead contaminated soil alone or in
combination with abatement of interior/exterior dust in order to reduce environmental lead.
Blood sampling and hand/elbow wipes are used to monitor biological lead levels. Monitoring
takes place before and after abatement in order to determine the efficacy of abatement.
This midterm project update presents an overview of the study approach as well as city-
specific study descriptions and preliminary baseline data. Study conclusions will be presented
in individual city reports which will precede the final compiled report The results of the
final compiled report will be presented at a symposium planned for Summer 1992.
2.2 Organization of the Midterm Project Update
This midterm update for the Urban Soil-Lead Demonstration Project presents both
general project information, city-specific descriptions, and supporting appendices. Section 3,
Project Design, outlines the phases of the Project, and Section 4 describes the Project
Schedule. Section 5, Abatement Procedures, contains a complete description of the soil and
dust removal efforts in each city. Section 6 describes several problems encountered to date
and the way they were solved. Section 7 presents the Protocols used in the Project, and
Section 8 discusses the QA/QC Guidelines for Field and Laboratory Practices. Section 9,
Summary of Pre-abatement Data, provides baseline data from biological and environmental
sampling.
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Appendix A is a detailed description of the Protocols for Sampling and Analysis used
throughout the study. Appendix B describes the External Quality Assurance/Quality
Control measures established for the project. Finally, Appendices C and D present City
Maps and Organizational Charts.
2.3 Project Participants
Several institutions in addition to the Project's primary managers (the City of Boston,
the Maryland Department of the Environment and the University of Cincinnati) are
contributing to the Project. The Kennedy Institute in Baltimore, the Boston University School
of Public Health, and the Cincinnati Health Department are playing integral roles in the
Project Technical assistance is being provided by both EPA and several other scientific and
public health organizations including: The Centers for Disease Control, U.S. Department of
Agriculture, Toronto Department of Health, Ontario Ministry of the Environment, Boston
Children's Hospital, State of Massachusetts Department of Environmental Protection, Battelle
Applied Statistics, Lockheed ESC and The Cadmus Group, Inc. The Georgia Institute of
Technology and SENES Consultants, Ltd., Ontario are also providing assistance. Appendix D
contains organizational charts for each of the three city organizations.
2.4 Lead in the Environment
Centuries of mining, smelting, and use have released millions of tons of lead (Pb) into
the environment. Mielke el al. (1983) estimated that the combustion of leaded-gasoline alone
emitted 5,000 to 10,000 metric tons of lead into the urban environment of Baltimore from the
1930s through the 1980s. A major national survey found that lead-based paint has been
applied to some 57 million privately owned pre-1980 homes (HUD, 1990). Forty-six million
of these homes have exterior lead-based paint This malleable yet resistant metal has also
been used extensively in a variety of products including storage batteries, pesticides, food-can
soldering, water pipes, and roofing materials.
Lead in the human body, whether at high or low concentrations, acquired over a short or
long-term (chronic) exposure, may result in a broad spectrum of adverse health effects. These
effects, called 'lead poisoning", include dizziness, hearing impairment, destruction of red
blood cells, delayed cognitive behavior, convulsions, coma, and death. While lead poisoning
can be treated, many of its effects on the nervous system appear to be irreversible.
Although the effects of lead appear to depend upon the level of exposure (a dose-effect
relationship), this correlation is complicated by differences in lead intake by different age
groups and by the propensity of lead to accumulate in various tissues in the human body.
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Cumulative poisoning can be difficult to detect because lead storage in tissues may result in
under-representative blood-lead (PbB) levels. Lead stored in bone may be released later in
times of stress causing delayed toxicity.
Young children are the population most at risk from excessive lead exposure and the
associated adverse health effects (ATSDR, 1988). This risk is primarily a function of the
childrens' physiological development and their frequent contact with lead-contaminated
components of their environment (U.S. EPA, 1986). During normal outdoor play activities,
they may ingest or inhale lead-based paint and contaminated dust/soil. Exposure also may
result from indoor contact with paint and contaminated dust which collects in carpets, on
drapes and furniture, and on other household items. The human fetus is also part of this
high-risk population; prenatal lead exposure due to mobilization of bone lead in the mother
during pregnancy may produce toxic effects including reductions in gestational age, birth
weight, and mental development (ATSDR, 1990). It was estimated that in 1984, over
400,000 fetuses were exposed to lead at maternal PbB levels above 10 ug/dL, a level recently
associated with early developmental effects (ATSDR, 1990).
Despite the introduction of childhood lead-screening programs in the early 1970s and
initiatives such as the 1971 Lead-Based Paint Poisoning Prevention Act, the Agency for Toxic
Substances and Disease Registry (ATSDR) found that nearly 17 percent of children in
Standard Metropolitan Statistical Areas (SMSAs) have PbB levels above 15 ug/dL (ATSDR,
1988). The Agency points out, however, that the lowest exposure level at which adverse
health effects can be reliably detected has consistently decreased, evoking concern that
developmental disturbances may occur at PbB levels of ten ug/dL.
Several studies have investigated soil and dust as potential lead exposure pathways.
Yankel et al. (1977) showed that lead in both soil and dust was independently related to PbB
levels. Building on that study, Stark et al. (1982) discovered that the most important
contributors to variation in childrens' PbB levels were soil-lead and exterior house paint lead.
Further, Rabinowitz et al. (1985) determined that lead levels in indoor dust and outdoor soil
were strongly predictive of PbB levels in a group of urban and suburban infants followed
from birth to two years of age. • • ;'
Yet the magnitude and extent of childhood lead exposure remains uncertain due, in part,
to a lack of source-specific and media-specific data. In addition, interrelationships exist
among exposure pathways. Fuel combustion and industrial emissions contribute lead to the
air that may cling to dust or settle in the soil. The weathering of leaded-paint may increase
the soil-lead concentrations. Lead may enter the food-chain via vegetable gardens, water, etc.
(Mielke et al. 1983). And while no single environmental lead source may be dominant, the
aggregate absorption of lead from multiple exposure pathways may result in unacceptable
internal levels.
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2.5 Project Background
In early 1987, the EPA convened a panel of experts to design a study capable of
determining what effect soil-lead abatement would have on childrens' PbB levels and to
develop selection criteria for study sites. Six cities submitted proposals, which were
evaluated at a workshop in November 1987. Baltimore, Boston, and Cincinnati were
subsequently chosen. Through its Regional offices, EPA entered into cooperative agreements
with the City of Boston (Region I), the Maryland Department of the Environment (Region
III), and the University of Cincinnati (Region V). The Centers for Disease Control agreed to
provide technical assistance for blood sampling and analysis. The EPA's Environmental
Criteria Assessment Office (ECAO), in the Office of Research and Development (ORD), also
arranged to provide technical assistance in project coordination, quality assurance/quality
control (QA/QC) management, and statistical analysis.
Planning workshops have been held regularly since March 1988. The early workshops
focused on the development of protocols and standard procedures for soil, dust, and handwipe
collection and analysis. Experts from Toronto, Canada, where soil abatement was being
carried out in a single neighborhood, participated in the workshops.
By November 1988, all three cities had assembled their research staff, facilities and
equipment EPA gave final approval for the individual project plans, including the Quality
Assurance Plans, by March 1989, and the work commenced. Periodic coordinating
workshops have provided the participants with an opportunity to discuss problems and
solutions, and to suggest design modifications.
2.6 Project Timeline
Although each of the three city studies is proceeding according to its own internal
agenda, the general project schedule still serves as the common timetable. Figure 1-1
presents the general project schedule while Figures 3-1 to 3-3 show the planned activities for
the individual cities. Each of the three city studies has successfully completed abatement
activities in study areas. . . .
Individual reports for the three cities are scheduled for completion by Spring 1992.
These reports and a final combined report will be presented at a symposium scheduled for
Summer 1992. ,
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2.7 Project Design
2.7.1 Project Hypotheses
Although a number of scientific studies have explored the relationships between PbB
levels and exposure to lead-contaminated media, this study has been designed to investigate
whether a reduction in soil-lead concentrations will result in decreased PbB levels in childrer
Measuring the amount of lead in blood is the most common method of assessing lead
exposure (ATSDR, 1990). The central hypothesis of the Urban Soil-Lead Demonstration
Project is that:
A reduction of lead in residential soil accessible to children will result in a
decrease in their blood-lead levels.
This hypothesis will be tested by comparing PbB levels in the study and control group
before and after abatement A secondary objective is to determine whether a reduction of
lead in residential soil will result in a corresponding reduction in the amount of lead-
contaminated dust on the hands of children. Additional individual city hypotheses are
described in Section 3.
2.7.2 Methodology
Each city developed its own specific set of eligibility criteria to identify, screen, and
select study areas, subjects, and specific sites. These criteria addressed characteristics of ti
populations and the neighborhoods in which they lived. In order to measure reductions in
both environmental and biological lead levels, the cities chose areas which exhibited elevai
soil-lead and PbB levels. The biological and environmental monitoring data thus reflect th
"targeting."
Over the course of the study, each city will conduct a sequential set of pre-abatemen
abatement, and post-abatement activities. This pattern may occur more than once. The pi
abatement phase establishes the baseline conditions (e.g., lead levels in water, soil, blood)
Observations made during this phase may highlight important systematic changes in PbB
environmental lead concentrations that are unrelated to the study abatement The abatemc
phase consists of the actual removal of soil and dust under carefully controlled conditions
The post-abatement phase is an extended period (up to one year) of monitoring designed
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determine whether the abatement reduces exposure and whether recontamination of the
neighborhood occurs.
2.7.3 Scope
Initially, the study encompassed a total of 785 subjects: 408 in Baltimore, 152 in
Boston, and 225 in Cincinnati. The Baltimore study includes children between the ages of six
months and six years. Subjects in Boston consist of children ranging from under one year to
four years old. The Cincinnati study population consists of children under one year to five
years of age at the time of recruitment.
In Baltimore and Cincinnati, the number of study subjects has changed because subjects
have moved, withdrawn consents, etc. Prior to initiating abatement, the cities selected a
sufficient number of replacement subjects to maintain the statistical power of the study.
These replacements included newborns, new residents, and newly consenting residents.
Baseline data was also collected on replacements.
2.8 Protocols
The protocols and methods used throughout the study are recognized standard ^B
procedures as well as techniques developed or modified specifically for this project Those
protocols developed especially for this project evolved over several months at workshops
attended by all participants.
While many of the protocols used in the study are common to the three cities, some of
the procedures are city-specific. Slight modifications in sampling/analysis methodology
reflect the logistical differences among individual projects. A complete description of the
protocols used in this study, as well as the city-specific modifications, can be found in
Section 7 and Appendix A.
2.9 Quality Assurance / Quality Control (QA/QC)
In order for any analytical measurements generated during this study to be valid and
interpretable, the sources of error for each unique measurement system must be identified and |
minimized. This is the primary function of QA/QC Experience has shown that major *
sources of error can occur at virtually any phase hi a project, from specimen collection to
improper equipment calibration to deterioration of the specimen. The QA/QC system used in
this project, then, addresses each of these stages.
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Given the QA/QC needs of the study, both internal and external quality controls were
used. Internal controls were developed and used by each city following approval by the
appropriate EPA Regional Office. External controls consisted of both biological (blood,
handwipes) and environmental (soil, dust) samples.
Environmental audits are being supplied by EPA while blood-lead analysis QA/QC
support is being provided by the Centers for Disease Control (see Appendix (B). Effective
QA/QC will ultimately help to ensure that any observed changes in participants' PbB levels
are not attributable to changes in monitoring, analysis, or laboratory methods.
2.10 Description of Baseline Data
To date, over 3,500 biological samples and nearly 25,000 environmental samples have
been collected. Preliminary baseline blood analyses indicate that close to 60% of the study
participants have PbB levels equal to or greater than 10 pg/dL, a level recently associated
with early developmental effects (ATSDR, 1990).
Preliminary baseline surface soil analyses have also been conducted in all three cities.
Soil samples are taken at both the surface 0-2 cm and at a depth of 13-15 cm. Average
surface soil concentrations were 571 ug/g (range from 22 to 7,500) in Baltimore, 2,619 pg/g
(range from below detection to 21,000) in Boston, and 505 pg/g (range from <20 to 23,400)
in Cincinnati. The analyses show that lead concentrations at 15 cm are consistently below
those of surface samples.
While all cities have sampled for dust, only the data from Boston are available for this
project update. These data indicate that lead concentrations range from below detection to
220,000 ppm with an average of 11,541 ppm. Twenty-five percent of the dust samples
exhibited lead levels in excess of 11,500 ppm. The dust analyses further show that dust from
areas around windows have higher lead levels (nearly ten times greater) than floor dust
Baseline environmental and blood-lead levels are found in section 9. Data is preliminary as
some additional studies need to be conducted to interpret data, particularly for environmental
samples.
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2.11 Final Reports
As noted above, this midterm project update contains city-specific study descriptions and
the sampling/analysis protocols used throughout the Project. In addition to study design,
scope, and timeline, the update includes relevant biological and environmental baseline data.
The update does not compare pre- and post-abatement lead analyses or present conclusions on
the effects of lead abatement. Results and evaluations of this nature will be presented in
individual final city reports to be completed by the Spring of 1992. These will precede the
final combined report that will be presented at a symposium planned for Summer 1992.
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3. PROJECT DESIGN
3.1 Project Hypotheses
The purpose of The Urban Soil-Lead Demonstration Project is to quantify the reduction
in childhood lead exposure that can be achieved from the abatement of lead contaminated
soil. The formal statement of the hypothesis is:
A reduction of lead in residential soil accessible to children will result in a decrease in
their blood-lead levels.
The Project will test this hypothesis by comparing PbB levels in the study and control
groups before and after abatement. A secondary objective is to determine whether a reduction
of lead in residential soil will result in a corresponding reduction in the amount of lead-
contaminated dust on the hands of children. Individual city hypotheses are described in this
section.
3.2 Methodology
All three cities are using a basic study design. Each city has slightly modified the basic
design to accommodate city-specific conditions.
The three city studies are structured to collectively provide an informative array of lead
exposure conditions including: presence or absence of exterior/interior Pb-based paint;
location of exterior play areas; wide range of soil-lead concentrations; and variable degrees of
ground cover. Several sources of environmental lead exposure are being assessed: food, air,
drinking water, and dust.
Exposure to lead-contaminated food is assumed to be comparable to national averages as
modified by information received from household questionnaires. Exposure to lead in the air
is determined from regional air concentration measurements and is known to be relatively
low. Measurements of first draw samples at the tap in each household provide the basis for
assessing the extent of lead exposure from drinking water. These three exposure sources are
similarly evaluated in each city. Assessment of lead-contaminated dust exposure varies by
project design, but is principally evaluated by using handwipes to determine the amount of
lead on the hands.
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Each city has planned several abatement activities. The following provides the status of
these activities to date.
Pre-Abatement
The initial design phase of the Project focused on selecting sites with elevated soil-lead
concentrations and recruiting participants with elevated PbB in these areas. Through lead-
screenings and family interviews, the cities evaluated candidate subjects against eligibility
criteria. Among these criteria were: length of time at current residence, plans to relocate,
baseline PbB levels (Boston's criteria for PbB was 5-25 ug/dL), subjects' access to soil
around the home, conditions of abutting properties, and for Boston, average soil-lead levels of
at least 1500 pg/g. The family interviews also elicited important behavioral information about
the children such as play activities, diet, and hand-to-mouth actions.
In addition to these eligibility requirements, other external factors influenced the
selection of study areas and subjects. For example, soil abatement activities could not
proceed without landowner consent. Additionally, the cities tried to avoid selecting sites in
which other lead abatement efforts (e.g., drinking water, exterior/interior paint) were
underway. Following baseline sampling, random assignment of selected sites to study/control
groups and children further mitigated the possibly confounding effects from concurrent
changes in the lead content of food or water.
Where possible, study sites consist of several city blocks, areas large enough to assure
the inclusion of sufficiently large numbers of children. These large study areas offer an
advantage over individual houses or apartment buildings because subjects* exposures to soil-
lead most likely result from multiple sources throughout lead-contaminated neighborhoods.
1 '-, • j ' ' " - - ' "3
Prior to abatement activities both environmental-lead and biological-lead levels were
determined. Environmental monitoring included sampling of soil, interior/exterior dust, paint,
and water. Biological monitoring consisted of venous blood levels of Pb and hand/elbow
wipe sampling in order to determine surface levels of lead on skin, free erythrocyte
protoporphyrin (PEP), total iron binding capacity (TIBC), and ferritin. Any child found to
have elevated PbB levels (i.e., above 25pg/dL) received appropriate medical follow-up
evaluation and necessary treatment While these children were'used in the project, they were
treated separately with respect to project'analysis. City-specific monitoring information is
presented in subsequent lections"of this Project update. „, , , .
Abatement
Abatement in Cincinnati started in August 1989, and in Boston in September 1989.
Technical contract problems delayed Baltimore's abatement until June 1990. Although lead
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removal efforts are varied across the three cities, they are targeted at soil and interior/exterior
dust. Soil with lead concentrations above 500 ppm is abated by removing the top six inches
and replacing it with clean soil and seed/sod, or crushed stone (Boston removed the top six
inches of all soil in yards). If the study concludes that soil abatement reduces childrens' PbB
levels, the cities will abate any previously unabated soil in control areas. (Regardless of PbB
levels, Boston will abate all previously unabated soil).
Baseline soil sampling by all three cities occurred in yards, public playgrounds and
schoolyards. Each city conducted abatement activities in yards. In addition, abatement was
conducted in playgrounds in Cincinnati.
Dust abatement in Boston and Cincinnati provides an opportunity to compare the relative
effectiveness of complete abatement of sites with dust-only abatement. Vacuum cleaning
equipment is used to remove exterior dust from curbs, gutters, and parking lots. Vacuuming
and washing floors, rugs, walls, and window wells are the methods for reducing interior dust
levels. Some cities are replacing rugs and stuffed furniture, which collect dust and thus act as
potential lead sources.
Post-Abatement
Environmental and biological lead levels will again be determined following abatement.
Post- and delayed-post screening for blood-lead, FEP, TIBC, fenitin, and hand-wipes will be
taken following soil abatement. The questionnaire interview will be repeated with each
biological screening.
Additional Phases
Each city has planned some activities unique to its own needs and circumstances. The
detailed, city-specific, project descriptions later in this section describe these activities, which
may include both second and third abatement phases. Continued environmental and
biological sampling will be conducted for up to one year following the last abatement period.
In order to accurately assess the effects of abatement, each city has established its own
database management system capable of recording, processing, and reporting the information
collected. Both the study participants and a team of statistical experts will perform
independent statistical analyses.
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3.2 Baltimore Study Design
The Maryland Department of the Environment is managing the Baltimore study under a
cooperative agreement with EPA, Region HI. As outlined under the general project design,
Baltimore is investigating the effects of soil-lead abatement on both PbB levels and the levels
of lead-contaminated hand dust. In addition to the primary study hypotheses, Baltimore is
also investigating an additional hypothesis:
A reduction of lead in residential soil mil result in a corresponding reduction in
the amount of lead in the interior household dust.
Although dust is being monitored for lead contamination, no dust abatement is being
conducted.
The basic steps of Baltimore's project are: sampling and measuring lead in the
environment; sampling and measuring lead in subject children; abating lead in the
environment; relating the change in environmental lead to the change in PbB; and monitoring
this relationship over an extended period of about one year. In addition to soil abatement,
Baltimore has stabilized exterior lead-based paint to prevent flaking and peeling of paint chips
that might contaminate post-abatement soil. Figure 3-1 presents a schematic diagram of the
Baltimore project Section 5.2.1 provides a complete description of abatement procedures
unique to the Baltimore study.
Potential indicators of the effectiveness of soil removal include:
• a post-abatement reduction in average PbB levels of the study group relative to a
control group and/or their own pre-abatement PbB levels;
• a reduction in lead recovered from handwipes; and
• a reduction in interior dust-lead levels.
3.2.1 Baltimore Project Study Areas
In selecting the two study neighborhoods, Walbrook Junction and Park Heights (see
maps in Appendix Q, Baltimore considered the following factors:
• communities identified through PbB screening and hospitalizations for lead toxicity to
have moderate risk for lead poisoning;
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• sufficient number of potential participants;
• sufficient number of pre-1950 houses in comparable condition;
• comparability of socioeconomic class and other demographic indicators;
• presence of removable soil; and
• low likelihood of concurrent lead paint abatement projects performed under other
funding mechanisms.
Noncontiguous neighborhoods were selected to avoid confounding results from crossover by
children between the two areas. After the completion of baseline sampling, a random method
was used to assign one of these as the study area (Park Heights). The other area (Walbrook
Junction) serves as the control area.
3.2.2 Baltimore Study Population
The Project set as its goal a study group of at least 100 children and an identical number
of children in the control group. In order for the study results to be statistically valid, the
sample size had to consist of at least 88 children in the study area and 44 in the control area.
The following criteria served as the basis for selecting the study subjects:
• Residence: child lives in one of the study areas;
• Length of residence: child has lived in the same house for at least 3 continuous
months and the family has no plans to move in the immediate future; and
• Age: child must be between six months and six years of age at the time of enrollment
in the study. Extra emphasis was placed on enrolling children in the one to four year-
old age group.
There were 408 children initially enrolled in the study: 200 in the study area and 208 in
the control area. At the outset of the Project, Baltimore anticipated an attrition rate of
approximately 20 percent per year, with up to a 50 percent loss over the study's three-year
duration. The use of incentives coupled with the exclusion of families planning to move
within the first three months of the study are measures adopted to keep attrition to a
minimum.
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At the beginning of the third year, 214 children remained in the study: 118 in the study
area and 96 in the control area. Attrition has been due primarily to families moving out of
the area (145) and landlords' refusals to sign consent forms for paint stabilization and soil
abatement (23). The recruitment statistics for the Baltimore study are shown in Table 3-1.
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Table 3-1.
Summary of Recruitment and Retention of Participants
in the Baltimore Project.
".•Area' '".
Study Area
Control Area
Total
Minimum
88
44
132
> 'Start '
200
208
408
Moved \
67
78
145
Decked
15
34
49
•?; •. Cttrrew •-
118
96
214
3.2.3 Baltimore Data Collection and Analysis
Three sequential biological and environmental samples were taken prior to abatem
Biological sampling for PbB, FEP, TffiC, ferritin, handwipes, and elbow wipes was coi
during an interview with each participating family. All participating children found to
either elevated PbB or abnormal FEP and ferritin levels received counseling and approj
medical referral. Children with PbB levels equal to or greater than 25 ug/dL were refe
the City Health Department Environmental sampling included exterior paint, soil, inte
dust, and water.
Three samples (including immediate post and delayed post samples) will be taker
following abatement. If the study shows that soil abatement results in a significant re<
in PbB, Baltimore will conduct abatement activities in the control area. The results w
incorporated into the statistical analysis, enhancing the accuracy of the results.
3.3 Boston Study Design
The Boston Lead Free Kids project is a randomized environmental abatement sti
designed to determine how the removal of lead-contaminated soil will affect children!
levels. Funding is through a cooperative agreement with EPA's Region I office. Th<
design has been accepted by the U.S. EPA, the CDC, the Massachusetts Department
Health and the Conservation Law Foundation. In addition, it has the full approval oi
Human Studies Committee of the Trustees of Health and Hospitals of the City of Bo
Section 5.3.1 contains a complete description of abatement procedures unique to the
study.
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All subjects enrolled in the study were randomly allocated to one of three groups: study
group, control group A, or control group B. The study group received removal of loose
interior paint, soil, and interior dust abatement in the first year. Control group A received
interior dust and loose interior paint abatement in the first year and will receive soil
abatement in the second year. Control group B received removal of loose interior paint in the
first year and will receive soil abatement in the second year. These different intervention
groups enable separation of the effects of soil and interior dust abatement.
3.3.1 Boston Study Area
The pool of potential subjects consisted of children up to four years of age living in the
Roxbury, Dorchester, Mattapan and Jamaica Plain neighborhoods of Boston. These
neighborhoods were chosen because they have a high incidence of childhood lead poisoning
and the occurrence of lead-contaminated soil is widespread (see maps in Appendix C).
Landlords were contacted and homes were visited to determine if potential study areas met
the following criteria:
• exterior paint has little or no chipping;
• premises have a yard of a specified size with dirt or grass cover that is accessible to
the child;
• premises have no more than eight residential units; and
• average or median soil-lead level around house foundations is greater than or equal to
1500 ppm.
3.3.2 Boston Study Population
The study relied on the ongoing city-wide screening efforts of the Boston Childhood
Lead Poisoning Prevention Program (BCLPPP) to identify potential-study subjects. Test
results of blood samples the BCLPPP received from eligible children between January
through June 1989, formed the basis for initial identification of subjects. Additional children
who lived in the same premise as the BCLPPP participant and were up to 4 years old also
became candidates for recruitment Home visits evaluated additional eligibility criteria:
family and landlord agree to participate;
child is mobile;
child has never exhibited lead poisoning;
family has resided in premises for at least three months prior to the baseline blood
test; and
family has no definite plans to move within three months of August 1,1989.
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Each eligible child received a pre-abatement PbB determination in the fall of 1989.
Children with PbB levels between 5 and 25 pg/dL were enrolled in the study. As noted, all
subjects were randomly allocated to one of three groups: study group, control group A, or
control group B.
There were 152 children initially enrolled in the study: 54 children in the study group, 51
children in control group A, and 47 in control group B (Table 3-2). Population attrition was
kept to a minimum by excluding families with plans to move within the first three months
and by providing incentives for continued participation. In addition, all subjects who move
are traced. Assuming a sample size of 120 children, the study should have a high probability
of detecting a statistically significant difference between the study and control groups (power)
if the true effect of the study intervention is to reduce PbB an average of 3 pg/dL.
Table 3-2.
Summary of Recruitment and Retention of Participants
in the Boston Project.
"IQHJBP '"^
Study Group
Control
Group A
Control
Group B
Total
Mininjam
50
50
50
150
™'5ttrt -
54
51
47
152
^oved*
11
8
3
22
propped
0
2
1
3
1 - Osa-eat '
43
41
43
127
Children who moved are still being tracked by the Boston Project.
3.33 Boston Data Collection and Analysis
Venous blood samples were used to determine PbB levels. Three blood samples were
scheduled over die course of the study: baseline sampling occurred prior to abatement
(beginning in September 1989); the second round occurred four to six months after baseline
(beginning in March 1990); and the third began about ten to twelve months after baseline
(September 1990). In addition, hand-lead determinations (handwipes) were conducted
concurrently.
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Data-gathering on major environmental sources of lead exposure covered exterior soil,
interior dust, paint and drinking water. These samples have helped characterize the childrens'
potential sources of exposure; and, if applicable, similar sampling after abatement will
document reductions in environmental levels of lead and the rate of recontamination. Lead in
paint, found on surfaces, will be measured after the final study blood test. If leaded paint is
found, deleading is strongly suggested.
Shortly after the first blood sample, a questionnaire was administered to the child's
parent or caretaker. The goals of the questionnaire were to gather demographic information
necessary to characterize the study population and to assess factors that bear on a child's
contact with various sources of lead (i.e., behavioral and dietary characteristics).
Multiple regression analysis is the primary analytic tool for testing the study hypotheses.
A mathematical model describes the extent, direction, and strength of the relationship between
the dependent variable (a child's blood or hand-lead level) and several independent variables.
Independent variables include the abatement group to which the child was assigned,
information on other sources of lead, as well as other characteristics that can affect a child's
lead level (e.g. age, gender, race, and behaviors).
3.4 Cincinnati Study Design
The University of Cincinnati is managing the Cincinnati study through a grant from
EPA, Region V, and a cooperative agreement with the Cincinnati Health Department. In
addition to the general hypothesis, Cincinnati is testing a second hypothesis:
Interior dust abatement, when carried out in conjunction with exterior dust and soil
abatement, will result in a greater reduction in blood lead than is obtained with
interior dust abatement alone, or exterior dust and soil abatement alone.
As illustrated in Figure 3-3, the Cincinnati study design is consistent with the general
design. Section 5.4.1 contains a complete description of abatement procedures unique to the
Cincinnati study. The primary objective of the Cincinnati demonstration project is to
determine whether procedures to abate the lead concentration in (1) soil, (2) exterior dust, and
(3) house dust, applied separately and in combination, are effective in reducing the PbB levels
of children. Subject children are up to five years of age and reside in either completely
rehabilitated housing or in nonrehabilitated housing which is in satisfactory condition.
Secondary objectives of this project are to:
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• determine the effectiveness of the abatement procedures in reducing the quantity of
lead on the hands of the children and the quantity of lead-contaminated dust in
residences;
• determine the rate of reaccumulation of household dust-lead;
• determine the factors associated with such reaccumulation;
• estimate the rate of exterior and interior recontamination; and
• identify factors that modify recontamination.
The specific questions to be answered in the Cincinnati Soil-Lead Abatement
Demonstration Project are as follows:
• Does interior dust abatement in rehabilitated (including lead-based paint abated)
housing in conjunction with soil-lead and exterior dust abatement, or interior dust
abatement alone, result in the reduction of PbB in children relative to children living
in rehabilitated housing in the control area where no abatement occurs?
• Does soil or dust abatement result in a covariant adjusted reduction in PbB relative to
each child's pre-abatement PbB?
• Does exterior abatement (exterior dust and soil) result in a significant reduction in PbB
relative to that in children in housing where no abatement occurs?
• Is the reduction in PbB and environmental lead transient or long term?
These questions will be addressed by tracking changes in lead concentration over a two
year study interval. Indicators of abatement effectiveness include:
a) reduction in average PbB of treatment groups relative to a control group or their own
pre-abatement PbB level;
b) reduction in lead recovered from hand wipes; and,
c) sustained reduction in interior dust lead levels and exterior surface dust levels.
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It is anticipated that soil and interior lead abatement will be two of the major incentives
for property owners and residents to participate in the study and, therefore, will be performed
in the remaining areas.
3.4.1 Cincinnati Study Area
Selection of several study areas with similar characteristics was important in order to
determine the impact of the exterior and interior abatement procedures (see Appendix C for
map). This was accomplished by selection of several areas within the study neighborhoods
where socioeconomic and ethnic backgrounds are similar. Other matching variables
considered include housing type, age of child, prior housing history, season, soil availability
per block (group match) and percent nonrehabilitated housing per block (group match).
In order to maximize the potential impact of soil-lead abatement on PbB reduction,
several features of the study area were also desirable. These include: a high percentage of
completely rehabilitated housing free of lead-based paint; a high percentage of young
children; and a high density of children exposed to accessible, lead-contaminated, soil.
An evaluation of Cincinnati neighborhoods revealed several areas that appeared to be
promising candidates for the soil-lead abatement project. Each neighborhood had 40 to 60
children under five years of age. The percent of land area that is soil ranges from about 20
to 27 percent, averaging about 24 percent. The soil exists primarily in large parcels of land,
such as common recreational areas.
3.4.2 Cincinnati Study Population
One hundred and eighty four eligible families with children less than five years of age
lived in the three study areas prior to study initiation. Seventy-nine percent of these families
agreed to participate in the study (Table 3-3). In June 1990, an additional 45 families were
recruited. They had moved into the study area after the initial recruitment but prior to soil
abatement. As of July 1990, 147 families with a total of 225 children were actively
participating in the study. This represents a retention of 77 percent of all recruited families, a
level that is consistent with initial estimates. Table 3-3 summarizes the preceding information
by study area.
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Table 3-3.
Summary of Recruitment and Retention of Participants
in the Cincinnati Project.
Area
Study Area
A
Study Area
B
Control Area
C
TOTAL
Eligible
Families
42
77
65
184
Recruited
Families
36
68
42
146
Families
Dropped/
Moved
9
25
10
44
Additional
Families
Recruited
0
19
26
45
Active
Families
27
62
58
147
Active
Children
43
99
83
225
There were 143 property owners with soil, exterior dust, and/or apartment buildings which
required abatement. Seventy three percent of these owners agreed to participate in the study.
Based on data collected in the ongoing prospective study of lead poisoning in Cincinnati,
an estimated 150 children between the ages of one and five years, with an average age of
three years at the start of the study, are needed to test the hypothesis of a significant effect of
soil abatement on PbB. This estimate assumes that only the soil abatement has a significant
effect. A total of 225 children were recruited for the study, 43 from Area A, 99 from Area
B, and 83 from Area C.
3.4.3 Cincinnati Data Collection and Analysis
Environmental and PbB monitoring were conducted in June 1989, just prior to the
initiation of abatement activities (August 1989) and in November of both 1989 and 1990. In
addition, environmental monitoring occurred in all areas, immediately after abatement had
been completed. Paint and water monitoring took place during the winter of 1990 and is
scheduled for late winter 1991. A final environmental and PbB monitoring will occur in June
1991 prior to abatement in the control area.
All the collected samples will be prepared and processed according to the study
protocols. The chemical analytical results and the necessary sampling information will be
double-entered into the data management system developed by the data management group
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and checked for errors. Family and housing information together with information on study
subjects' activity patterns also will be collected and entered into the database, following
established procedures. All project data will be available to project working groups and
investigators after it is checked for errors.
Once data entry tasks are complete, calculation of the important statistical variables will
begin in order to test the study hypotheses. Mathematical and statistical models will be
developed to understand the impact of environmental lead abatement on study subjects and on
their residential environments.
The project is using a geographical information system (GIS) known as ARC-INFO in
order to fully understand the data and to provide the necessary capability to spatially relate
human samples to environmental samples. Specifically, this system will be used to spatially
relate children to exterior and interior environmental lead data. In addition, the relationships
among environmental samples themselves can be examined. ARC-INFO will examine the
relationships between paint lead, soil-lead, exterior dust-lead, and interior dust lead, as well as
the pattern and rate of environmental recontamination following abatement
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4. PROJECT SCHEDULE
Although each of the three city studies is proceeding according to its own internal
agenda, the general project schedule still serves as the common timetable. Each removal site
will undergo a pre-abatement, abatement, and post-abatement phase. The pre-abatement phase
establishes the baseline conditions (lead levels in water, soil, blood, etc.) Observations made
during this phase may highlight important systematic changes in PbB and environmental lead
concentrations that are unrelated to the abatement. The abatement phase is the actual removal
of soil and dust under carefully controlled conditions. The post-abatement phase is an
extended period of monitoring to determine the impact of abatement on exposure reduction
and the possible increases in exposure due to recontamination of the neighborhood.
Figure 1-1 presents the general project schedule, while Figures 3-1 to 3-3 show the
planned activities for the individual cities. Each of the three city studies has successfully
completed abatement activities in study areas. Data are not yet available, however, for the
most preliminary estimate of the impact of soil abatement on childhood lead exposure.
The individual city reports are scheduled for completion by Spring 1992. These reports
and a final combined report will be presented at a symposium planned for Summer 1992.
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5. ABATEMENT PROCEDURES
5.1 Introduction
The reduction in environmental lead is being accomplished by removing lead-
contaminated soil (greater than or equal to 500 ppm lead) and internal/external dust; or, in the
case of Boston, the top six inches of soil is removed from all project sites. Some cities are
conducting complete abatement, while others are performing only partial abatement. The
following section is an overview of the abatement procedures conducted in each city:
Baltimore, Boston, and Cincinnati.
5.2 Baltimore
5.2.1 Soil-Lead Abatement Procedure
The analytical results for lead levels in the soil determined the soil abatement procedure.
If the lead levels in the soil were equal to or greater than 500 ppm, the soil was removed to a
depth of six inches and was replaced with topsoil and sod. If the lead levels in the soil were
less than 500 ppm, bare spots of the study property were reseeded to reduce dust levels. The
following procedure was conducted:
Preparation
1. Residents are notified of the starting date and estimated date of completion. They
are instructed to remove all movable objects from the work area. The contractor
subsequently controls access to the work area. At least seven days before the work
begins, heavy cardboard signs are posted at each property in a location clearly visible
to passersby.
2. Blood is taken from the workers and tested prior to starting the project, again two
months later, and at the conclusion of the project
3. Windows and doors adjacent to the work area are taped with duct tape or equivalent
waterproof tape. The contractor uses a light water spray to eliminate or capture any
dust produced by the abatement procedures.
4. Workers are required to change into work clothes, including shoes, upon arrival at
the site and remove work clothes before leaving the work site. Each worker is
required to wear a half-mask air purifying respirator equipped with high efficiency
filters while working. Eating, drinking, and smoking are not permitted in the work
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area. The contractor is provided water, dressing rooms, washrooms, and toilet
facilities for the use of his employees.
5. Limits of the area are located and marked off with stakes and tape, or some other
approved method. Any trash within the work area limits is removed and disposed.
Any existing shrubs, plants, or ground cover other than grass are removed and placed
in an adequate storage site. Fencing is also removed and placed in storage.
Implementation
1. The soil is excavated to a depth of six inches. The area to be excavated is misted
with water to control dust levels. The excavated soil is disposed in an appropriate
manner, depending on the toxicity or lack thereof.
3. "Clean" soil (earth material obtained off site), which is previously tested (at least 5
days prior) for lead and found to have less than 50 ppm is placed and compacted.
4. After the refill is in place and compacted to 6 inches, the area is covered with two
inches of clean topsoil and sodded. Shrubs, plants, and/or ground cover are
replanted. The contractor is required to seed existing bare areas with established
stands of grass. Seeding consists of loosening the existing soil to a depth of two
inches, removing all clods, stone, and other foreign materials larger than three inches,
applying a 5-10-10 fertilizer at a rate of five pounds per 100 square feet and seed
mix No. 2 at a rate of 0.25 pounds per 100 square feet, raking fertilizer and seed into
the prepared bed to a depth of not more than 1/4 inch, compacting the soil with an
approved lawn roller, and applying an approved mulch. All existing fencing removed
during the course of soil-lead abatement work is replaced.
5. At the end of each workday, dust removal is conducted by vacuuming all surfaces
adjacent to the work area with a HEP A vacuum cleaner. After complete removal and
cleanup, the site is ready for inspection.
6. All lead contaminated debris including soil, filters, and disposable clothing is
disposed in accordance with hazardous or solid waste regulations.
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5.3 Boston
5.3.1 Soil-Lead Abatement Procedure
The following is an overview of the soil removal procedures for the fall of 1989 and the
fall of 1990. No major changes were made in the specifications for this work between the
two years.
Preparation
1. The areas to be abated are marked off with yellow caution tape. A decontamination
area is established outside the work area, usually on the sidewalk in front of the
house. Access to the house is maintained via either the front or back door with a
caution-taped alley which avoids the work area.
2. Any fences which are in the way of the soil removal are taken out, to be replaced
after abatement. In some cases access had to be negotiated with neighbors whose
yards abut the yard to be abated.
3. Plastic dropcloths are placed over the sidewalks and other areas immediately outside
the work area to contain any spilled soil. Plastic dropcloths are also placed where
the soil is loaded into the truck and are overlapped by a heavy plastic tarp attached to
the side of the truck to contain any spilled soil.
4. The areas to be abated are marked to indicate where the surface of the soil is at the
beginning of the abatement. These marks serve as a guide to determine how much
soil has been removed.
Implementation
1. The top six inches of soil are removed using a combination of small bulldozers and
hand labor. Where there is an established tree or hedge, the soil is removed by hand
labor as close as possible to the plant Water is sprayed over the work* area
frequently to keep the soil moist This was found to be an effective way to reduce
airborne dust during abatement
2. Geotextile fabric is placed over all areas where soil has been removed. It is secured
at the edges to prevent it from shifting. This fabric is a spun polyester felt which is
water-permeable.
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3. Soil, bark mulch, or crushed stone, is placed over all abated areas to a depth of eight
inches. The extra two inches of soil allow for settling, which will occur in the
months following the soil removal. All new soil has been tested to be sure that it
contains less than 150 ppm of lead. The crushed stone is used in driveways and
parking areas. Bark mulch is used where grass would not grow well.
4. Sod is placed over the new soil. The residents of the home are given a hose and a
sprinkler, as well as instructions for caring for the sod.
5. All workers wear tyvek suits and boots. Any worker who leaves the work area must
pass through a decontamination area where he disposes of the tyvek suit and washes
off his boots. All wash water from the decontamination area is poured into the work
zone after the soil is removed and before the geotextile fabric is put down. The soil
is taken by truck to a disposal site, where the driver and the site operator sign a bill
of lading indicating the origin and quantity of the soil.
5.3.2 Interior Dust Abatement Procedure
The purpose of the interior dust abatement is to significantly reduce the amount of
lead-bearing dust in the treated homes. The two primary activities involved in this process
are vacuuming with a HEPA vacuum and wiping surfaces with either a wet cloth or an
oil-treated rag (for furniture). The surfaces treated in this manner are floors, woodwork,
walls, and furniture.
For dust abatement, the vacuuming on floors is timed. Carpets are vacuumed for three
minutes per square yard. Wood and tiled floors are vacuumed for two minutes per square
yard and washed with a trisodium phosphate solution. Area rugs are vacuumed on each side,
then rolled up so that the floor beneath can be vacuumed and washed.
5.4 Cincinnati
5.4.1 Soil-Lead Abatement Procedure
There are three abatement strategies for soil depending upon the concentration of lead in
the top and bottom of the IS cm core and the condition of the grass cover. If the average
lead concentration in the 15 cm soil column is 500 ppm, regardless of the adequacy of the
grass cover, the soil will be removed, replaced, and the area resodded. If the average lead
concentration hi the column is less than 500 ppm but the average concentration in the top
2 cm is 500 ppm or higher regardless of its grass cover, the area will be cultivated, to reduce
the concentration hi the top 2 cm to less than 500 ppm, and resodded. For areas where grass
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cover is adequate and the lead concentration is less than 500 ppm in both the top 2 cm and in
the column, no abatement will occur. If the soil-lead concentration in the top 2 cm is
300 ppm but less than 500 ppm, the average concentration in the column is less than 500 ppm
and the grass cover is inadequate the area will be resodded. No soil abatement will occur in
areas where the grass cover is inadequate but the concentration in the top 2 cm is less than
300 ppm and in the column is less than an average of 500 ppm. Adjacent sampling lines
with lead concentrations requiring different abatements according to the above guidelines will
each be abated according to that required for the line with the higher lead concentration.
The soil abatement is accomplished in one of three ways depending upon the
concentration of lead in soil column. Some soil requires resodding or, in some cases, the
addition of topsoil to a site or part of a site prior to resodding. The purpose of the topsoil is
to provide a base for the sod or perhaps to fill in the depressed areas, so that proper drainage
can occur. In those cases where tilling is the appropriate method of abatement, tilling is
required for a specified period of time. After the required tilling, soil samples are taken by
the Environmental Monitors and analyzed for lead concentration. This analysis takes place in
one of two ways. The soil is processed in the XRF Soil Lab at the University of Cincinnati
Medical Center, or it is analyzed in the mobile XRF laboratory, borrowed from the EPA. The
mobile unit allows for more rapid processing of the soil samples. This permits the
completion of each site in a more timely fashion. In either case, the results of the XRF
analysis may require an additional period of tilling of the soil.
On those sites where the concentration of lead requires the removal of soil, the soil is
excavated to a depth of six plus inches and is replaced with topsoil having a lead
concentration of less than 50 ppm, if such soil is available. Where excavations are required,
the soil is removed by mechanical equipment, with either loaders or backhoes. Appropriate
techniques are used to prevent spills of contaminated soil at the abatement along with
techniques for the containment of dust Prior to loading of hoppers or dump trucks, 2 mi-
thick polyethylene is placed into the hoppers or dump trucks to prevent soil from being
spilled through cracks in the tailgate or beds of the transport vehicles. Hoppers or dump
trucks are then covered with tarps for transport. In order to ensure that the soil is transported
to the appropriate dump site, all trucks are logged off the abatement site by the Site
Inspectors and logged into the appropriate dump site by officials at the dump site. In order to
contain dust, excessively dry soil is moistened with water. Sites are not permitted to remain
open for more than 24 hours except in the case of inclement weather. No site remains open
over a weekend period.
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5.4.2 Interior Dust Abatement Procedure
Interior dust abatement follows the completion of exterior dust abatement in an area if
both are occurring during the same time period. Interior dust abatement consists of a
combination of vacuuming with a HEPA equipped vacuum and wet cleaning non-carpeted
surfaces (including window sills and wells) with a detergent. The vacuuming of floors is
timed; carpets are vacuumed a total of three times at a rate of one minute per square yard
each time.
Selected carpets and upholstered furniture are also replaced. Residents with one child in
the study are provided with replacement carpeting for one common room, for example the
living room, plus the child's bedroom. Residents with two or more children in the study
receive an additional carpet for a total of three carpets. Residents with a child in the study are
also eligible for the replacement of one standard sofa and one standard chair.
5.43 Exterior Dust Abatement Procedure
Exterior dust abatement occurs immediately after soil abatement has been completed in a
particular area. Streets are generally abated one side at a time, principally because of the
requirement that the street be free of parked cars for complete abatement to occur. The study
areas generally have more onstreet than offstreet parking and it is not practical to restrict
parking on both sides of a street at any given time. Therefore, abatement occurs one side per
day with the alternate side abated the following day. The paved surfaces are cleaned with
vacuum equipment capable of removing greater than 99 percent of the dust after two passes
as determined under test conditions. In some situations, hand tools are needed to loosen
material in cracks and crevices particularly along alleys and on sidewalks.
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6. STUDY IMPLEMENTATION AND PROBLEM RESOLUTION
6.1 Introduction
Each city approached the planning and implementation of the lead study in its own
unique way. While the studies have proven to be an overall success, several difficulties and
problems were encountered along the way. These problems were recognized and their
solutions developed and implemented. The following section describes some of the problems
and subsequent resolutions experienced by the participating cities: Baltimore, Boston, and
Cincinnati.
6.2 Baltimore
6.2.1 Recruitment of Participants
Initially, the recruitment of subjects for the Baltimore study was done by the
Environmental Health Aides. The Aides went to the houses in the two designated areas and
explained the program. They explained, in detail, the study's goals and how it would benefit
the children, and the need for repeat visits to contact the mother of the child. The Aides
would then enroll the eligible children into the project While this method was effective, it
proved to be extremely time consuming. The Baltimore study participants realized that they
could more efficiently manage their time and resources if they hired people specifically for
the purpose of public relations.
The first solution was to hire a public relations person to promote the project in the
selected communities. This person was responsible for informing the selected communities of
the study's basic goals and how these goals would benefit the children, as well as the
communities involved. This person contacted the media for television coverage of both
biological and environmental sampling activities. She worked with a local college to develop
television and radio spots explaining the project and its importance to children. She also
visited local churches and community groups to explain the project and elicit their support for
the project. She explained that the Environmental Health Aides would be visiting homes and
enrolling subjects into the study.
The Baltimore study also hired a Community Outreach person to work with the Public
Relations Officer and the Environmental Health Aides to promote the enrollment of study
participants. She arranged for the training of the Health Aides in community outreach
techniques, worked with them on how to handle difficult situations, and acted as a liaison
between the project and the communities in the study. She distributed flyers on the project in
the elementary schools in the area to families that had children in the target age groups.
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Several biological screening clinics were established in the community elementary schools to
increase enrollment in the study.
The Environmental Health Aides were then assigned to door-to-door recruitment at
alternate times (evenings and weekends) in addition to normal business hours. Every house in
each community was contacted by someone in the study. If the mother of the eligible child
was not at home on the first visit, literature on the project was left and a return visit was
scheduled.
These measures proved to be successful in resolving the problem. Within three months,
408 children were recruited into the study and tested for blood lead levels.
6.2.2 Attendance at Biological Screening Sessions in Baltimore
Although the Environmental Health Aides were contacting and enrolling potential
subjects into the Baltimore study, another problem developed: attendance was low for
scheduled appointments for the biological screening of the children. The Baltimore study
participants stressed health education and developed several incentives to encourage a larger
degree of participation.
The first solution was to have the Community Outreach person and the Environmental
Health Aides place more emphasis on the positive aspect of the mother's concern for her
child's present and future health. When appointments were rescheduled by the Biological
Coordinator, emphasis was placed on how the project could help the mother in her concern
for the child's health. They began offering biological screening in community elementary
schools so that mothers could bring children in to be enrolled and tested as they brought
siblings to school. Furthermore, staff members, in all their contacts with individuals and
community groups, stressed the importance of the need for personal and community-wide
education for PbB screening.
The next solution was to offer incentives to the mothers who brought their children into
the biological screening clinic. A variety of incentives were tried during different time
periods and included the following:
• Tee shirts with the project's logo on them for all children screened.
• One month passes on the Metro Transportation System for all mothers who brought
their children in during a particular month. '
• Food coupons to local grocery stores for mothers who brought their children in during
a different month.
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• A party for all participants' family members with refreshments and entertainment at
the end of the first biological screening.
Additional recruitment was undertaken prior to abatement in the study area (Park
Heights) where attrition has been a problem mainly due to families moving away. Pre-
abatement data (biological and environmental) of these children were collected. The aim was
to recruit additional children and obtain pre-abatement results on them to ensure adequate
power for the study. The control area had more than enough children even with attrition to
provide enough subjects.
These measures have been effective at increasing attendance at biological screening
sessions. Scheduled attendance increased from 15 to 20 percent of appointments to an
average of 60 percent. The health education and incentives continue to be used.
6.2.3 Property Owner Participation
Participants who owned their own homes were willing to have their home's environment
tested for lead and to enroll in the intervention phase of the study. However, some Baltimore
landlords were hesitant to allow their rental properties to be in the study; less than 30 percent
agreed to have their properties in the study. They were concerned that participation in the
study would leave them vulnerable to law suits related to the possibility of lead poisoning of
the children in their properties. Several lawyers in the area had been actively seeking clients
who were lead poisoned and who wanted to sue the landlord for compensation. The landlords
wanted the State to indemnify them from future cases for their cooperation in the study. The
State of Maryland could not do this. The Baltimore project, however, developed several
solutions.
The project solicited the cooperation of the Baltimore Property Owners Association
(POA) to support the project among its members. The Project Manager spoke at POA
training sessions concerning lead abatement of properties. The POA also discussed the
project in its newsletter and sent a separate letter specifically stating the purposes of the
study. This letter requested that property owners sign consent forms to participate in the
study. Those property owners who did not respond to mailings were invited to attend one of
two sessions in which the project and its benefits to property owners were explained. The
POA participated in these sessions as well. While the POA was not entirely supportive, the
organization did provide some access to the landlords.
The Project Manager then sent a letter to all owners who had not yet responded to the
request to participate in the study. This letter answered questions that were raised by the
property owners who had attended the meetings. A letter was also sent to potential and/or
active subjects asking them to express to their landlords their interest in staying in the study.
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The letter also urged them to request that their landlord sign the consent to participate in the
study. Photos of houses before and after paint stabilization were used to help convince rental
property owners of the benefits of participation.
While this problem was not entirely resolved, the percentage of cooperative property
owners greatly increased. Eventually, 75 percent of the property owners agreed to participate
in the study.
6.2.4 Technical Problems Related to Stabilization and Abatement Contracts
Several unforseen problems delayed the development of contracts for paint stabilization
in the study and control areas and soil abatement in the study area. The extended time
needed for recruitment of participants and the unwillingness of property owners to participate
in the study, resulted in the project manager being delayed in developing needed contracts.
Two paint stabilization (one for each area) and one soil abatement (study area) contracts were
completed and put out to bid in early 1990. The contracts were only for those houses for
which there were consents at the time of submission for bid and covered 77 (out of 123)
houses for paint stabilization and 29 (out of 60) houses for soil abatement. With greater
participation by property owners needed, these contracts became inadequate. The State of
Maryland contract regulations limits to 10% the amount of increase that can occur without
submitting a new contract The original two contracts were for $95,000.00 and the final
contract amount was for $450,000.00. In addition, the company that was awarded the
contract for soil abatement was unable to fulfill the contract and it was mutually agreed that
they would withdraw from the project
A new contract incorporating concurrent paint stabilization in each area immediately
followed by soil abatement in the study area was developed by June 1990 and put out to bid
utilizing expedited procurement This contract was awarded in July 1990 and was
immediately protested by a competitive bidder and taken to arbitration. Following a formal
hearing, final judgement was made and work started in August 1990. The paint stabilization
was completed in October 1990. The soil abatement was completed in November 1990.
6.2.5 Maintenance of Accurate Project Subject Data
The Baltimore project subjects are in a continuous dynamic mode. Careful monitoring of
subject movements, status, age, maternal condition, owner occupant moves, and landlord
shifts need to be closely monitored and on a readily available database.
In order to effectively manage the database, the Database Manager and Outreach
Coordinator were assigned to the maintenance of an accurate and reliable project subject
report. The Database Manager was directed to restructure and clearly identify the appropriate
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files and to generate subject reports on a weekly basis. This report is utilized by the
Outreach Coordinator and is returned to the Database Manager with all corrections and
modifications clearly indicated. Additionally, these reports are provided to the Environmental
and Biological Coordinator for their review and comment. These are then returned to the
Database Manager.
This method has been successful and there is now a complete and accurate account of all
subjects who have ever been in the study. The database is up-to-date and accounts for the
present status of each subject It is possible to link family, property, children, and
environmental files to compare and analyze the biological and environmental data.
6.3 Boston
6.3.1 Recruitment and Retention of Study Participants
A potential problem was the recruitment and retention of study participants. The success
of the study depended, in part, on recruiting and retaining sufficient numbers of participants.
This was essential so as to provide a large enough sample to effectively test the study's
hypothesis.
The Boston Childhood Lead Poisoning Prevention Program (BCLPPP) was used to aid in
the identification of children. This program has data about the majority of children screened
in the neighborhoods of interest (those neighborhoods with the highest rates of lead
poisoning). The study used as wide a range of blood lead levels as was practical, and
included the ranges 5-25 pg/dL. Children with blood lead levels greater than 25 ug/dL were
not chosen due to concern that they would receive medical and possibly environmental
interventions that might confound study results. The lower limit blood lead value was 5
ug/dL because of concern that lower levels would not show an effect of soil abatement A
related concern was that the BLPPP often had data derived from fingerstick lead tests. This
concern was addressed by confirming all potential subjects' blood lead levels with venous
blood leads before final enrollment
The recruitment and retention of participants were fostered by several approaches:
• An active and visible community relations program and subject education effort was
mounted. This ensured that residents of the target communities were aware of the lead
poisoning problem in their communities, the risks that lead poisoning posed for their
children, and were aware of the program at the time that project staff attempted to
recruit them. In addition, project staff were educated in the epidemiology, long-term
effects, prevention, and treatment of childhood lead poisoning so that they could
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discuss these issues with potential subjects and convince them of the importance of the
project and its potential benefits to individual children, the community, and the nation.
Participating families were offered $25 per month in gift certificates for local
supermarkets and general purpose stores as long as they participated in the study.
Even if they moved, they were eligible for these incentives as long as they stayed in
touch with the project staff and agreed to provide access to environmental and child
based samples (blood and handwipes) and project interviews. All families completing
the project were given a $150 gift certificate.
Project staff were enthusiastic, well trained, well supported by the project's
management, often experienced in home visitation, and frequently came from the
target communities. This led to a close rapport with participating families.
Families were not enrolled if they had plans to move during the next three months.
Project activities were very intrusive and disruptive to families and we made every
effort to minimize family disruption by scheduling project activities at their
convenience, taking children to childrens' museums and restaurants during work on
their homes, and offering alternative housing if necessary during interior lead paint
abatement.
6.3.2 Lead Contaminated Soil Disposal
A great deal of energy went into identifying a location to dispose of lead contaminated
soil that passed the Extraction Procedure (EP) test After exploring multiple options, some of
which were not used because of distance from the excavation site or political concerns, a
quarry was identified that abutted a cemetery in a Boston neighborhood not involved in the
study. This worked well until the city councilor from that neighborhood raised concerns
about the potential hazard of lead contaminated soil to this neighborhood. This problem was
resolved by continuing lead contaminated soil abatements and temporarily storing soil on city
owned property while staff from Region I of the EPA, the principal investigator and other
members of the Lead Free Kids Staff, and representatives from the mayor's office met with
the city councilor and concerned citizens and convinced them that dumping the soil in the
quarry and covering it with unleaded soil posed no risk to residents of this community.
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6.3.3 Frozen Ground During Lead Contaminated Soil Abatement of the Study Group
in the Winter of 1989-90.
The project had a very narrow window of time in which to accomplish soil abatement for
the study group. Before these abatements were completed, the soil froze in Boston, much
earlier than anticipated, as Boston experienced the coldest December in recorded history last
year. This problem was addressed by using jack hammers and backhoes to loosen soil so that
abatements could proceed.
6.4 Cincinnati
6.4.1 Public Relations
Shortly after the funding announcement was made, a joint press conference with the
University of Cincinnati and the Cincinnati Health Department was held at the University
Medical Center. The press conference was well-attended by radio, television and print media.
A video of the television coverage of this event was obtained and has been useful in staff
training programs. Aside from the above area-wide publicity, all other public relations efforts
have been directed on a "need to know" basis to neighborhood leaders, property owners, and
residents.
Two neighborhood organizations in Cincinnati became somewhat displeased with our
activities early in the project One case involved a neighborhood group that eventually
received title to a building that we had evaluated as a possible project office/clinic space, but
subsequently decided against. The other was a neighborhood that was included in our initial
census but had to be removed from further consideration because not enough young children
resided in that location. In both situations, meetings and other activities took place which
eventually resulted in the lessening of their displeasure.
During the course of abatement in 1989, the major problem encountered in the abatement
areas originated with the use of the equipment selected for exterior dust abatement The
VacAll generated noise. There were three complaints about the noise registered in the abated
area. Some residents, however, indicated that the potential benefit of having a cleaner
neighborhood made the discomfort acceptable. Because of the potential for additional
problems in the second round of abatement activities, a decision has been made to use
equipment other than the VacAll. The noise generated by the new abatement equipment has
been measured and has been found to be compatible with background noise in the
neighborhoods.
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Most potential public relations problems have been reduced in the abatement areas
because of continued communication with residents and community leaders. Prior to soil
sampling, a flier was distributed to residents announcing the abatement plans. For the amount
of disruption caused by the abatement in the first round of abatement activities, there were
very few complaints. Positive communication with owners and residents during the course of
the Cincinnati project has been continually stressed. When discussing abatement plans with
an owner, visits are arranged at the owner's convenience. This attention to owners' concerns
has been beneficial to the success of the project.
Most owners were very cooperative. One major landlord refused to give permission to
abate common hallways and exterior paved areas on his property. This affected more than
one half of the housing units in the abatement area. One other property owner refused to give
permission to sample a large soil area of approximately five thousand square feet
Fortunately, this site is relatively inaccessible and is covered by vegetation.
Public property under the control of the Cincinnati Recreation Commission has been
readily available for sample collection and abatement activities. Two small recreational areas
were abated in 1989. It is expected that five small recreation areas will be abated in 1990
along with some other property.
6.4.2 Recruitment of Participants
Prospective study families were identified by conducting a door-to-door census. If no
one was at home during the census, a flier was left at the door to announce the future plans.
In some cases property managers were also contacted. Two-person census teams were always
used. At the conclusion of the census, the following recruitment approach was used:
• Letters were mailed to and meetings were held with community leaders and property
owners to announce the project.
• Letters describing the soil project were mailed to each eligible family (children less
than 5 years of age).
• Recruitment teams personally visited each caregiver receiving a letter to discuss the
project and ask the caregiver to enroll.
i
• An appointment for blood collection was given to the caregiver at the time of
enrollment.
• An appointment reminder phone call was made one day prior to the appointment day.
Families without phones received a mailed reminder.
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• Families were reimbursed a fixed amount for transportation cost incurred.
• A very modest reward was given to each cooperative child following the blood
collection.
• Both lead related and general child rearing educational information literature was
given to the caregivers.
As a result of these measures, over 79 percent of the families initially eligible for recruitment
into the study agreed to participate.
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7. PROTOCOLS
The protocols and methods used throughout the study consist of recognized standard
procedures as well as techniques developed or modified specifically for this project. Those
protocols developed especially for this project evolved over several months at workshops attended
by all participants. The resultant policies and procedures maximize the quality and consistency
of field and laboratory performance.
While many of the protocols used in the study are common to the three cities, some of the
procedures are city-specific. Slight modifications in sampling/analysis methodology reflect the
logistical differences among projects. A complete description of the protocols used in this study
can be found in Appendix A.
As approximately 22,000 soil samples will need to be collected over the life of the study,
a standard methodology was needed to analyze for soil lead. The wet digestion procedure using
nitric acid, with analysis, by Atomic Absorption Spectroscopy (AAS) or Inductively Coupled
Plasma Emission Spectroscopy (ICP), has proven costly and time consuming for soil samples.
Therefore, project participants conducted an interlaboratory calibration study to evaluate X-ray
Fluorescence (XRF) as an alternate procedure for soil lead analysis. Laboratories from the
following organizations participated in the study: the Maryland Department of the Environment,
the University of Cincinnati, EPA, the U.S. Department of Agriculture (USDA), and Georgia
Institute of Technology.
Representatives from the three cities first collected ten urban soil samples. Samples were
then air-dried, crushed, and separated into two particle size fractionations. Each city sent aliquots
of the 20 sub-samples to the other four laboratories. Soils were analyzed using: (1) XRF, (2)
wet digestion using hot nitric acid, (3) wet digestion using cold nitric acid, (4) analysis of lead
by flame AAS, and (5) analysis of lead by ICP. Soil calibration samples were provided by
USDA.
Good correlation was observed between the XRF and the wet digestion method. There was
also good correlation of results between the two laboratories that conducted the XRF tests.
Correlation between the XRF and digestion methods was good up to 2,000 ppm soil lead. Work
is currently underway to establish the correlation between the XRF method and the wet-digest
method above 2,000 ppm soil lead.
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8. QUALITY ASSURANCE/QUALITY CONTROL GUIDELINES FOR
FIELD AND LABORATORY PRACTICES
8.1 QA/QC Standards for Soil, Dust, Drinking Water, and Hand wipes
The quality assurance standards for this project set forth the policies and procedures that
maximize the quality of field and laboratory performance. They were developed over a
period of several months at workshops attended by all of the participants. Necessary
modifications in these procedures were approved at these workshops. The goal is to maintain
an active QA/QC program to provide analytical data of known and sustained quality and
ensure a high professional standard of the analytical data generated. Appendix B contains a
detailed description of QA/QC plans for blood analysis and procedures for developing audits
and standards for soil, dust, and handwipes.
8.1.1 Sample Collection
All samples are required to be collected by personnel trained in sampling procedures.
Samples that are to be analyzed for lead are collected and stored in clean, previously unused,
sample containers. The containers are labeled according to established procedures and
recorded on appropriate field collection tracking sheets. All incoming samples are delivered
directly to the laboratories. As the samples are accepted, they are assigned a laboratory
sample number and the submission form is dated with the current date.
8.1.2 Analytical Methodology
Analyses of lead in soil are carried out using the XRF analyzer. Ten percent of the
samples are replicated. Blanks and different standards are included throughout each tray run,
according to individual laboratory protocols. Cities used either XRF or nitric acid digest for
interior/exterior dust analyses. Handwipes are analyzed for dust using nitric acid digestion.
Drinking water analyses are performed using graphite furnace atomic absorption spectroscopy.
Paint is analyzed using the XK2 and XK3 lead-in-paint analyzers or PGT XRF analyzer.
8.13 Laboratory QA/QC
The minimum requirements set forth in the Project QA/QC protocol dictate the
following.
• All quality control records must be maintained and available for easy reference or
inspection;
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Blind audit samples must be inserted into the sample stream by the project QA/QC
officer. The analyst must not be able to identify the audit samples and must not know
the concentrations of lead in the audit samples. The lead concentrations in the internal
audit samples, but not the external audit samples, are known to the QA/QC officer,
who will monitor the performance of the analytical laboratory;
External audit samples must be analyzed according to established project protocols. If
problems arise, they must be corrected, and a follow-up performance sample must be
analyzed.
A minimum daily control is to be established such that:
- National Bureau of Standard (NBS) or comparable calibration curves are prepared
and subsequent calibration curves verified (daily checks must be within + 10
percent of original curve);
- The working standard curve is verified by running an additional standard sample if
20 or more samples per day are analyzed (checks must be within ± 10 percent of
the original curve); and
- The purchase of standard (or reference) material is accompanied by a certification
or assay of composition.
Although not required, the following standards of QA/QC are very desirable in a
laboratory:
• Routine preventive maintenance performed on balances and the Kevex unit;
• Class S weights available to make periodic checks on balances;
• An NBS standard analyzed once per quarter and the measured value within the control
limits established by NBS;
• At least one replicate sample run every 20 samples to verify the precision of the
method;
• Standard deviation obtained and documented for all measurements being conducted;
and
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• Quality control charts or a tabulation of mean and standard deviation used to
document validity of data on a daily basis.
8.2 QA/QC Standards for Blood Analyses
Like the QA/QC standards for soil, dust, drinking water and handwipes, the QA/QC
standards for the PbB level testing were developed at workshops attended by all of the
participants. Because of the distinctly different nature of the sample, somewhat different
standards need to be followed. The goal, however, is still to provide analytical data of known
and sustained quality and ensure a high professional standard of the analytical data generated.
The following is a brief description of the internal and external requirements for QA/QC for
blood analyses. A more detailed and complete description of the formal protocols appears in
Appendix B.
8.2.1 Elements of the QA7QC System
In order for any analytical measurements to be valid and interpretable, the sources of
error for each unique measurement system must be identified and minimized. This, then, is
the major function of quality control. In the specific example of PbB measurements, the
following have been shown from experience to be the major sources of error jt^
• contamination of the specimen during collection, storage, or analysis;
• deterioration of the specimen by clotting, denaturation, or other processes;
• instability of the measurement system, either over a short (within run/day) or long
time span;
• improper calibration of the measurement system; and
• errors in data handling, storage, or reporting.
QA/QC therefore must include a number of components, both within and external to the
laboratory including: 1) collection of an uncontaminated specimen; 2) preservation and
shipping (if needed) of the specimen under conditions that assure integrity, 3) monitoring of
the analytical method performance to include instrumental stability, maintenance, and
performance of the analyst(s); and 4) accuracy and completeness of all data, including
specimen identification, data reduction, and data interpretation. The critical elements of
composing each of these areas include: 1) specimen collection, 2) specimen preservation and
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shipping, 3) analytical method performance, 4) bench and blind quality control materials, 5)
accuracy and blanks, and 6) data integrity.
8.2.2 Specimen Collection
All specimen collection equipment must be proper|y screened to define any detectable
levels of the analyte and to estimate the variability of tlMs type of contamination. Written
protocols for specimen collection detailing all sampling equipment and its use, precautions to
avoid contamination, and other requirements (time of d&y, fasting/non-fasting state of subject)
which might affect specimen integrity must be in place.
8.2.3 Specimen Preservation and Shipping
Proper packing, storage and shipping temperatures are critical to the secure delivery of
the specimens. Timely receipt of specimens must also be ensured. Detailed shipping and
specimen log forms should be kept to allow description of each specimen and to record any
variances from collection or shipping protocols.
8.2.4 Analytical Method Performance
The analytical method used must demonstrate precision and accuracy in the appropriate
analytical range, yet be simple, rugged, rapid and cost-effective. Ideally, the detection limit
should be ca. 2 pg/dL with precision about 5 percent at the 10 pg/dL level for the proposed
study.
Instrumental stability, and by inference "method" stability, should be documented by
analysis of control materials, both "bench" and "blind". It is desirable for materials with
certified values of the analyte of interest to be analyzed regularly to demonstrate method
accuracy. The protocol suggests that at least 10 percent of the specimens be quality control
pools.
8.2.5 Bench and Blind Quality Control Materials
Blind quality control pools should be inserted at a rate of 5 percent by a source external
to the laboratory. These specimens should be in the same type of container and labelled with
pseudosubject numbers such that they are indistinguishable from true subject samples. The
protocol suggests that the blind (and bench) pools have two concentrations - one in the
"expected" range of values for the majority of subject samples and one at or near the
"decision level" for undue exposure. It is important that the blind materials be truly blind to
the analyst for maximum effectiveness in the detection of analytical system error. The
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pseudosubject numbers used in labelling the blinds should be decoded by the supervisor only.
and that analytical run should be evaluated on the basis of pre-established control limits.
The use of quality control charts for means (X bar) and ranges (R) is essential. It is
suggested that 20 runs be made for the characterization of all quality control materials and
that these data be analyzed by two-way analysis of variance (ANOVA). Quality control
charts should be in use by the analyst for each run for the evaluation of "bench" or known
blood controls (and by the supervisor for blinds) by use of mean and range control limits,
such that corrective actions needed may be made in a timely way.
Criteria for repeat analytical runs (due to "out of control" condition as indicated by
results from quality control samples) are dependent on the number of pools in the QA/QC
system.
Inclusion of blind splits (duplicate samples within run, with different identification
numbers such that identification by the analyst is prevented) is suggested at a 5 percent rate.
Some split specimens may be submitted to an external laboratory for verification of accuracy
or comparability. If specimen collection constraints allow, it is recommended that at least ten
percent of the specimens be split and submitted to an external laboratory.
Criteria should be established as to "acceptable" agreement with the external laboratory.
8.2.6 Accuracy and Blanks
Blanks, consisting of samples in which ultrapure water is processed through the entire
analytical procedure, are a useful component of the QA/QC program. The data from these
determinations can be used to evaluate potential contamination in the laboratory environment,
as well as to estimate the limit of detection of the analytical method.
Establishment of accuracy through the regular analysis of reference materials or proficiency
testing pools is an essential part of good laboratory practice, and will help establish the
accuracy of the method. The pools used for this accuracy assessment should be as close to
identical to the survey samples as possible.
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8.2.7 Data Integrity
Data logging should be performed for each run in approved notebooks or other data
forms as soon after each run as possible. Electronic data entry may be desirable either as an
adjunct to or replacement for hard copy. It is recommended, however, that instrumental data
be collected in hard copy in such a way that all data can be independently verified or
reconstructed.
Data reduction should be standardized. All records of calculations should be secured and
available for review.
Instrument records and logbooks must be maintained for each instrument including the
following.
• Operations manuals with updates as provided by the manufacturers;
• Service manuals and schedules of recommended preventive maintenance;
• Maintenance logbooks containing entries describing all maintenance performed on the
instrument both by the multi-element laboratory personnel, as well as qualified service
engineers; and
• Sample logbooks containing a record of all samples analyzed listed by date of
analysis. These logbooks contain pertinent information, such as sample identification,
instrument conditions, and analyst. Any special modifications made to either the
instrument or to the analytical protocol are also noted.
8.3 Data Reduction, Validation, and Reporting
An important element in the quality control program is the validation of data by the use
of accuracy and precision determinations. Precision describes the degree to which data
generated from replicate measurements differ from one another. Accuracy refers to the
correctness of the data. Replicate samples are analyzed periodically. Analysis and replicated
data is also graphically illustrated by plotting the numerical difference between replicates
versus sample number. The mean and standard deviation are calculated for sample data.
8.3.1 Maintenance of Referenced Data Sets
Data sets used in statistical QA/QC procedures such as instrument calibration or
construction of quality control charts should be saved at regular intervals. If the referenced
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data set is modified or corrected subsequently, such changes should be noted on both the
archived data set and the new data.
When elements of separate data files are merged, correctness of the merged files should
be checked against the original files. This is particularly critical in linking diverse
environmental and biological data for the same child and household. Correct data files that
have been created should be saved at regular intervals, prior to further modification.
8.3.2 Data Quality
Ancillary information should be maintained about data quality, including:
• treatment of missing data such as replicate samples;
• methods for reporting and dealing with data below analytical detection limits or
practical quantitative limits; and
• identification of "outliers" or other data that were set aside for reasons of apparent
internal inconsistency.
8.3.3 Statistical Methods
Statistical methods used in QA/QC data reduction and interpretation should be referenced
(see pp. B-5 to B-7 and B-38 to B-39 in Appendix B). Other methods may be used as
circumstances require, with timely notification of the Project Officer. Due recognition should
be given to the heterogeneous nature of the samples and the possibility of encountering highly
skewed distributions of environmental lead data.
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9. SUMMARY OF PRE-ABATEMENT DATA
9.1 Summary of Pre-Abatement Blood-lead Concentrations
Means, medians and ranges of PbB measurements for the three study areas are shown in
Table 9-1. Note that the data from Boston reflect enrollment of children with pre-abatement
levels of 5 to 25 pg/dL, as the city deliberately omitted children with PbB values less than 5
or greater than 25 pg/dl.
Table 9-1.
Combined Summary of Pre-Abatement Blood Lead Concentrations.
•<^ilttL-;ki
0-4.9
5-9.9
10-14.9
15-19.9
20-24.9
25-29.9
30+
Total
Mean
Median
Geometric
mean
Coefficient of
variation
Baltimore
28
139
122
71
32
5
11
408
12.5
11.5
12.4
52
Boston1
NA
44
62
36
10
NA
NA
152
12.6
12.0
11.9
32.9
Cincinnati
22
87
59
30
13
11
3
225
11.7
10.0
9.9
18.7
''^:Wtf,£r
50
270
243
137
55
16
14
785
12.3
i^&w&fM
6.4
34.4
31.0
17.5
7.0
2.0
1.8
100.0
'Boston selected children with PbB levels ranging from 5 pg/dL to 25 pg/dL.
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9.2 Summary of Pre-Abatement Source and Pathway Data
Summaries of the available pre-abatement soil- and dust-lead data for the Baltimore,
Boston, and Cincinnati projects are shown in Tables 9-2, 9-3 and 9-4, respectively. A
summary of the available pre-abatement soil- and dust-lead data for all three cities combined
is presented in Table 9-5. Currently, dust values are available only for Boston. Data from
Boston indicate that interior dust-lead levels were significantly higher in window wells than
the levels found on floors. Lead concentrations in window wells ranged from less than 100
pg/g to 222,000 pg/g, with an arithmetic mean of 21,100 pg/g.
Soil-lead levels were similar in Baltimore and Cincinnati. The mean surface lead
concentrations were 571 ug/g in Baltimore and 505 pg/g in Cincinnati, while the mean
concentrations at the 15 cm depth were 365 pg/g and 371 pg/g, respectively. As expected,
concentrations were higher in Boston (the surface mean was 2620 pg/g and the mean at 15
cm was 1882 pg/g). This was because an initial eligibility criteria in Boston was a median or
average soil-lead concentration of at least 1500 pg/g around house foundations. Recruitment
in Baltimore and Cincinnati did not have a minimum soil-lead concentration eligibility
requirement.
Table 9-6 compares the soil-lead concentrations at three percentile points for each of the
cities. In addition to the differences seen in the table, soil-lead distributions also differed
widely in their relative variability. The coefficient of variation (ratio of the standard
deviation to the arithmetic mean) for surface samples ranged from 113 percent in Baltimore,
to 90 percent in Boston, and 298 percent in Cincinnati (see Tables 9-2 to 9-4). The
corresponding PbB concentrations, however, do not show the same range or pattern of relative
variability. The effectiveness of the soil-lead abatement will be assessed from the
longitudinal data in which PbB levels are observed over time in the same children.
Summaries of available pre-abatement lead data for other environmental measurements
(paint, water) and hand/elbow wipe lead are presented in Tables 9-7, 9-8, and 9-9 for
Baltimore, Boston, and Cincinnati, respectively. A combined summary of all three cities is
presented in Table 9-10. Ten percent of the paint samples had concentrations greater than
13.2 mg/cm2 in Baltimore and greater than 1.7 mg/cm2 in Cincinnati, reflecting the fact that
in Cincinnati recruitment focused on homes that previously had been completely rehabilitated.
Water levels of lead ranged from 0 to 420 pg/L in Baltimore, from less than one to 387 pg/L
in Boston and from less than 1.6 to 53.5 pg/L in Cincinnati. These variations reflect the
differences in aggressiveness2 of the waters in the two cities.
Aggressiveness is the ability of water to leach or corrode metals in the distribution (plumbing) system.
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Table 9-2.
Summary of Pre-Abatement Soil and Dust Data for the Baltimore Project.
Minimum
90th percentile
Geometric mean
^ot yet available
<80
371
655
1200
7500
570.9
391.5
113
cm
<80
254
441
737
3800
364.8
252.1
105
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Table 9-3.
Summary of Pre-Abatement Soil and Dust Data for the Boston Project1
Minimum
Median
75th percentile
90th percentile
- -Maximum
Sril r '.Mean
^^•j&aiw*
Ihist(Mg/g)
Floor
»«^3
«.<•
<50
1200
2500
5000
80000
2461.9
1077.9
225.2
Wtttdfcir
•- vi^48»F:
: - $*,', " ?•'•$? -, ..
& , ' "$?,* '
<50
10800
29000
51000
220000
21061.8
7313.7
137.5
Combined
/'3*&&^\
\ \^^«- % !; ^.x
- '"^ , , ,-
<50
2400
11500
34000
220000
11541.9
2744.9
195.8
soa&g&K
, Surface
;(%2«»i>
-' ft«715 - '
<200
2000
3500
5000
21000
2619.7
1892.4
89.8
•> '•• '•V^ ^
4tsw*;«ik,
^•WPH*''
<200
1400
2400
3900
19000
1882.4
1283.9
98.8
1Soil eligibility criteria in Boston was a median or average soil-lead concentration of at least 1500 (ig/g around house
foundations.
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Table 9-4.
Summary of Pre-Abatement Soil and Dust Data for the Cincinnati Project.
Minimum
75th percentile
Dust(ng/g)*
floor
Window
^ot yet available
Soli (ug/g)
Surface
<20
108
319
1375
23400
505
83
297.59
«m
<20
98
357
894
15800
371
49
263.01
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Table 9-5.
Combined Comparative Summary of Pre-Abatement Soil Concentrations.
\ v.
No. of Samples
surface
13-15
Minimum
2000
3500
5000
1400
2400
3900
Cincinnati
108
319
1375
98
357
894
'Percentile
Lead concentrations are in pg/g
3Soil values above 2000 ppm may be revised once the correlation between XRF and wet digest methods above 2000 ppm
soil-lead is established
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Table 9-7.
Summary of Pre-abatement Data for Other Sources in the Baltimore Project.
Minimum
Paint
2.44
6.88
13.17
70.1
5.15
2.39
143
2.5
6.5
21.4
420
8.40
3.86
282.9
Handwipe
2.0
8.3
13.4
20.95
288.5
11.89
7.69
156
EJbow wipe
*
2.0
1.5
2.79
5.52
24.2
2.47
1.16
132
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Table 9-8.
Summary of Pre-abatement Data for Other Sources in the Boston Project
Minimum
7Stli
1 Not yet available
<1
8.3
24.1
59.6
387
24.2
8.3
200.3
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Table 9-9.
Summary of Pre-abatement Data for Other Sources in the Cincinnati Project.
Minimum
Median
'Not yet available
Paine
0
0.5
1.1
1.7
20.5
0.8
0.6
190
Water
3.4
13.6
2.3
1.9
83.1
.Whir*
9.0
53.5
3.9
2.3
98.7
Handwipe1
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February, 1991
BIBLIOGRAPHY
Agency for Toxic Substances and Disease Registry. (1988) The Nature and Extent of Lead Poisoning in
Children in the United States: A Report to Congress. Atlanta: US Department of Health and Human
Services, Public Health Service; DHHS document no. 99-2966.
Agency for Toxic Substances and Disease Registry. (1990) Toxicological Profile for Lead. US Department
of Health and Human Services, Public Health Service. ATSDR/TP-88/17.
Mielke, H.; Anderson, J.; Berry, K.; Mielke, P.; Chancy, R.; Leech, M. (1983) Lead Concentrations in
Inner-City Soils As a Factor in the Child Lead Problem. American Journal of Public Health 73: 1366-
1369.
Rabinowitz M; Leviton A; Needleman H; Bellinger D; Waternaux C (1985) Environmental correlates of
infant blood lead levels in Boston. Environmental Research 38 (1) 96-107.
Stark, A.; Quah, R.; Meigs, J.W.; DeLouise, E. (1982) The Relationship of Environmental Lead to Blood-
Lead Levels in Children. Environmental Research, 27:372-383.
U.S. Department of Housing and Urban Development. (1990) Lead-Based Paint: Interim Guidelines for
Hazard Identification and Abatement in Public and Indian Housing. Washington, D.C.: Office of
Public and Indian Housing.
U.S. Environmental Protection Agency. (1986) Air quality Criteria for lead. Research Triangle Park, NC:
Office of Health and Environmental Assessment, Environmental Criteria and Assessment Office: EPA
report no. EPA-600/8-83/028aF-dF. 4v. Available from: NTIS, Springfield, VA; PB87-142378.
Yankel, A.J.; Von Lindem, I.; Walter, SIX (1977) The Silver Valley Lead Study: The Relationship Between
Childhood Blood Lead Levels and Environmental Exposure. J. Air Pollut. Control Assoc. 27:763-767.
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APPENDIX A
PROTOCOLS FOR SAMPLING AND ANALYSIS
A-l Baltimore Protocols A-l
I. Soil Sampling A-l
E. Soil Analysis A-3
ffl. Household Dust Sampling A-7
IV. Dust Analysis A-8
V. Handwipe Sampling A-15
VI. Handwipe Analysis A-16
VH. Paint Chip Sampling A-19
Vm. Paint Chip Analysis A-20
K. Paint Stabilization A-23
X. Drinking Water Sampling A-25
XI. Drinking Water Analysis A-25
A-2 Boston Protocols A-28
I. Preliminary Soil Sampling A-28
H. Soil Sampling A-29
m. Soil Analysis A-33
IV. Recontamination of Soil - Sampling A-37
V. Household Dust Sampling A-38
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VI. Dust Analysis A-40
VII. Handwipe Sampling A-51
VIII. Handwipe Analysis A-52
DC. Lead Paint and Site Inspection A-53
X. Water Sampling A-58
XI. Water Analysis A-59
A-3 Cincinnati Protocols A-62
I. Soil Sample Collection A-62
H. Soil Analysis A-69
HI. Surface Dust Collection A-72
IV. Surface Dust Analysis A-75
V. Dustfall Analysis A-77
VI. Exterior Dust Sample Collection A-79
VII. Exterior Dust Analysis A-90
VIIL Handwipe Sample Collection A-94
DC. Handwipe Analysis A-95
X. Paint Sampling Protocol Using XRF Analyzer A-97
XI. Water Analysis A-100
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APPENDIX A: Protocols for Sampling and Analysis
Appendix A-l. Baltimore Protocols for Sampling and Analysis
I. Baltimore Soil Sampling
A. Site Description
For each location, a detailed drawing should be made that shows the boundary of the lot, the
position of the main building and any other buildings such as storage sheds or garages, the
position of the sidewalks, driveways, and other paved areas, the position of the play areas if
obvious, and the position of the areas with exposed soil (grassy or bare), roof rain spouts and
general drainage patterns.
In addition to the diagram, briefly describe the location, including the following information:
Type of building construction
Condition of main building
Condition of property (debris, standing water, vegetation cover)
Nature of adjacent property
Presence and type of fence
Animals on property
Apparent use of yard (toys, sandbox, children present)
Underground utilities
B. Soil Area Description
For each soil area (i.e. front patch, front yard, back yard, side yards) identified on the general
diagram, draw a full page diagram showing the approximate dimensions and position relative
to the building foundation. Indicate vegetation and bare soil areas, as well as obvious traffic
patterns. Identify the category of land use, such as roadside, property boundary, adjacent to
foundation, play area. Mark the sample location on the diagram.
C. Sampling Schemes
The sampling scheme depends in part on the dimensions of the area and on the apparent
usage that might influence exposure. Measure the soil area to determine the sampling
scheme. Select the sample scheme for each soil area that adequately characterizes the
potential exposure of children to lead in the dust from this soil. Identify the suspected areas
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of high lead concentrations and the assumed general distribution pattern of lead concentrations
at the soil surface.
Small Area Pattern. Measure and mark off an area 20 inches from the base of the
foundation into the soil area. Repeat measuring and marking at the boundaries. The area
inside the marked pattern indicates the sampling collection area. If the sampling
collection area is less than two meters in each dimension, a single composite sample may
be taken if it appears that such a sample would adequately represent the soil area.
(Collect two sample bags, one bag marked top and the other bag marked bottom.)
Large Area Pattern. Measure and mark off an area 20 inches from the base of the
foundation into the soil area. Repeat measuring and marking at the boundaries. The area
inside the marked pattern indicates the sampling collection area. Collect one composite
sample at the foundation and one composite sample at the boundary of the yard if the
area is less than 10 feet wide. (Collect four sample bags, two bags marked top and two
bags marked bottom.) Collect an additional composite sample at an imaginary sample
line between the foundation and boundary sample areas if the yard is larger than 16 feet
wide. (Collect six sample bags, three bags marked top and three bags marked bottom.)
Very Large Area Pattern. Measure and mark off an area 20 inches from the base of
foundation into the soil area. Repeat measuring and marking at the boundaries. If a
is wider than 16 feet and more than 20 feet long then divide the yard into a vertical half
and a horizontal half. Collect one composite sample at the from each section of the yard.
(Collect twelve sample bags, six bags marked top and six bags marked bottom.)
D. Sample Collection
Collect ten randomly selected cote samples from within 0.5 meters of the sampling point.
The cores make a composite sample identified as a single sample. Record composite
information on the sample sheet
Clean and decontaminate the corer after each sample collection. Remove vegetation and
debris from the soil at the point of insertion into the soil, but do not remove any soil or
decayed litter. Drive the corer in to the ground to a depth of IS cm (6 in.). If this depth
cannot be reached, the corer should be extracted and cleaned, and another attempt made
nearby. If repeated attempts do not permit a IS cm core, take the sample as deep as possible,
and record the maximum penetration depth on the sample record sheet
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Combine the top two inch segment of each core into one composite sample and combine the
bottom two inch segment of each core into second composite sample. Remove debris and
leafy vegetation from the top sample material. Do not remove soil or decomposed litter from
the sample material. This is the most critical part of the soil sample and is likely to be the
highest in lead concentration.
Assemble composite soil core segments in clean previously unused plastic bags suitable for
prevention of contamination and loss of the sample. Record the sample identification number
on the bag and the sample record sheet. Store the composite soil sample at ambient
temperature until submitted to the laboratory for analysis.
Clean the corer after collecting each sample composite by reinsertion of the corer into the soil
of the next sampling area.
Draw field blanks for each soil area by inserting the core borer into randomly selected
locations within the sample area. These blanks are drawn prior to sample collection and at
the conclusion of sampling.
E. Sample Handling and Storage
Seal the sample bags to prevent loss or contamination of the sample and storage samples in a
cool, dry location.
Record-keeping and Sample Custody Initiate soil sample records for each location. These
consist of a location diagram and description, a plot diagram for each distinct soil plot, and
sample record sheet for each sample in a plot. Sequentially number samples bags. Record
sample numbers on location diagram, soil area description, and sample record sheet. Deliver
the sample to the laboratory and release the sample to the laboratory personnel for analysis.
IL Baltimore Soil Analysis
A. Sample Preparation
1. Receive soil samples at the laboratory. Identify sample information to be logged in on
the Lead in Soil Processing Sheets. Record the contract number, sample information,
date, time and total sample number on the processing sheet
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Example:
Date received: 03/30/89
Time: 12:30 p.m.
Total Number of Samples Received from: 41 from Ms. Merrill Brophy
Sample Identification Number: #590312565
Site address: 2092 W. Preston Street
Area: Front yard
2. Record the soil sample information on the XRF Run Sheets. Assign analysis
identification number to the sample.
Example:
The last Fine Soil Fraction sample number was 0436, then the next sample would
be a Total Soil Fraction sample numbered 0437.
3. Specimen containers and XRF sample cups are to be prepared before soil samples can
be processed.
a. Label specimen containers. Include the date, the analysis number, the sample's
identification number, and the particular soil fraction - Fine or Total.
b. Label XRF sample cups. Include only the analysis (cup) number.
4. Air dry samples overnight at room temperature. Use disposable weigh boat or Kraft
paper to air dry sample. Wear gloves during this process.
a. Label weigh boat Include the sample's identification number, and the sample's
analysis number (cup number).
b. Place weigh paper (glassine) on disposable weigh boat
c. Pour sample onto weigh boat to air dry.
d. Return samples to corresponding bags after air drying.
5. Samples in bags are to be placed on top of the Kraft paper before pulverization.
Pulverize sample in bag with steel roller until crushed.
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6. Sieving process must be done under the hood. Gloves and dust and mist respirators
must be worn throughout this process.
a. Sift pulverized sample in a 2 mm 9.0 mesh sieve by using the back of a gloved
hand to crush larger particles.
b. Place the sample that passed through the sieve into a specimen container labeled
total soil fraction.
7. Run the total soil fraction through an open pan riffle sampler to obtain a homogenous
sample.
8. Place the homogenized total soil fraction sample into the open pan and riffle once.
This will divide the sample in half.
9. Then take one half of the sample and put into the open pan and riffle to yield a
quarter sample. The remaining three-fourths of the sample should be placed into a
specimen container labeled total soil fraction.
10. Pass the quartered sample in a 250 pm 60.0 mesh sieve. This represents the fine soil
fraction. Discard particles that cannot pass through the 250 pm sieve.
11. If the quartered sample does not seem to be at least two grams, then take the total soil
fraction from its specimen container and repeat steps 5-8. After enough fine soil
fraction has been collected, remember to take the soil that did not pass through the
250 pm and replace it back into the specimen container labeled total soil fraction.
12. Clean sieves by tapping on a hard surface to remove residual particles. This must be
done between sample processing.
13. After all samples have completed steps 4-9, the total soil and fine soil fraction of a
sample should be placed in XRF sample cups. Use a spoon or spatula to place the
sample into labeled XRF sample cup.
14. Seal XRF sample cup with mylar film and a ring.
Samples are now ready to be analyzed by Kevex XRF. List samples on the XRF mo sheet
according to their analysis number that corresponds with the sample's identification number.
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B. XRF ANALYSIS
1. Approximately 2 g of loose soil sample are poured into sample cups (Somar Labs,
Inc., Cat. No. 340), fitted with windows of 1/4 mil thick X-ray polypropylene film
(Chemplex Industries, Inc., Cat. No. 425). The sample cup should be at least half
full.
2. The sample cup is sealed with a sheet of micropourous film (Spex Industries, Inc.,
Cat. No. 352A) held in place by the snap-on sample cup cap. The exact weight of
the sample is not important, but should be in the range of 2-6 g.
3. The instrument configuration for the Kevex Delta Analyst Energy Dispersive X-ray
spectrometer is:
a. Kevex Analyst 770/8000 Excitation/Detection Subsystem:
1) X-ray tube: Kevex high output rhodium anode
2) Power supply: Kevex 60 xC, 3.3 mA.
3) Detector/cryostat: Kevex Quantum - UTW lithium, drifted silicon.
b. Kevex Delta Analyzer:
1) Computer mainframe: Digital Equipment Corp, PDF 11/73
2) Computer software: Kevex XRF Toolbox n, Version 4.14
3) Disk drives: Iomega Bernoulli box, dual drives, 10 MB
4) Pulse processor: Kevex 4460
5) Energy to digital converter: Kevex 5230 •
c. Operating conditions:
1) Excitation mode: Mo secondary target with 4 mil thick Mo filter
2) Excitation conditions: 30 kV, 1.60 mA
3) Acquisition time: 100 livetime seconds
4) Shaping time constant: 7.5 microseconds
5) Sample chamber atmosphere: air
6) Detector collimatan Ta
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d. Analytical conditions:
1) Escape peaks, but not background should be removed from all spectra.
2) The intensity ratio, defined as the integral of counts in the Pb (LA) window
divided by the integral of the counts in the Mo (KA) Compton scatter window,
should be determined for each spectrum.
3) The intensity ratios for the standards should be used to determine a linear least
squares calibration curve.
At the time of the analysis there was no established detection limit for this type of analytical
method. However, the lab employed a sandard calibration range from 78 to 4,000 ppm Pb
due to the low levels of lead in soil. The lab worked within this linear range for aU analyses.
m. Baltimore Household Dust Sampling
Household dust sampling should be carried out at the time of the environmental visit to the
home of the study participant
For this study, the household dust samples are defined as the samples that represent dust most
likely to impact on a child's hands during indoor activity. This would include dust on
window sills, and furniture, as well as dust on toys and other objects likely to be handled by
children. A minimum of three areas should be sampled: at the main entrance to the
household, and two areas most frequently used for play activities by the child or children.
Additional areas may be selected that represent: 1) secondary entrances to the household
(back or side doors); 2) sources or accumulation of dust within the household (paint, rugs,
upholstered furniture); 3) additional play areas or other areas of activity frequented by the
children.
The sample has two components that are important to interpreting lead exposure, the
concentration of lead in die dust and the amount of dust, or loading, on the surface. The
concentration of lead in dust appears to be closely related to the amount of lead on children's
hands, whereas the amount of dust on surfaces is an indicator of the importance of this route
of human exposure. At least 10% of the samples should be over a defined area to determine
the household loading factor.
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Sketch the approximate layout of the residence and select to sampling. Bear in mind that
some areas, such as entryway, may reflect outdoor dust to a greater degree than others.
The sampling apparatus is the Sirchee-Spittler Hand Held Dust Vacuum unit which is
attached to a 'Dustbuster' hand held type vacuum. Prior to the sample collection the sample
collection screen must be clean.
For some samples, both the weight of the dust and the lead concentration of the dust will be
measured. In this case, it is necessary to sample a defined area, so that the results may be
expressed in pg Pb/m2. Mark the 4' x 4* sample area with tape. The surface of the sample
area is vacuumed with back and forth strokes about 1-2 inches in width. The vacuum is most
efficient if the head is held parallel to the ground at a 45 degree angle. A single pass across
the surface of the sample area is sufficient to collect adequate sample amounts. After dust
sampling, the vacuum unit is kept in an upright position until the sample screen is ready to
be removed. Turn the vacuum off and remove the sample screen. Empty the contents of the
sample screen into a labeled-reinforced paper envelope. Seal the envelope with scotch tape.
The sample amount required for analysis is equal to 2 grams of dust If the sample amount
from the area is not sufficient additional sample material may be collected from another 4'x
4* sample area and added to the initial sample.
Record sample data on the appropriate chain of custody form. Transport the sample to the
laboratory in a manner to ensure upright envelope delivery.
IV. Baltimore Dust Analysis
A. Sample Preparation (XRF)
1. Identify sample information to be logged in on the Lead in Dust Processing Sheets.
Record the contract number, sample information, date, time and total sample number
on the processing sheet.
Example:
Date received: 06/30/90
Time: 12:30 p.m.
Total Number of Samples Received from: 41 from Ms. Merrill Brophy
Sample Identification Number. #590312565
Site address: 2092 W. Preston Street
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Area: Front door area
Area Collected (square feet): 4
Record the dust sample information on the XRF Run Sheets. Assign analysis
identification number to the sample.
Example:
The last dust sample number was 0436, then the next sample would be numbered
0437.
2. XRF sample cups (Somar Labs, Inc., Cat. No. 340) are to be prepared before dust
samples can be processed.
a. Assemble XRF cup for weighing.
1) Place the 21 mm ring, with tabs down, on a flat surface
2) Cover with a 3 X 3 inch piece of mylar film (Spex Industries, Inc., Cat
No.352A)
3) Snap/fit the 24 mm ring over the mylar film and inner ring
b. Label XRF sample cups. Include only the analysis (cup) number.
3. Transfer dust from envelope, as quantitatively as possible, onto a 60.0 mesh, 250 um,
3 inch wide stainless steel sieve with a pan and cover.
a. Discard particles that cannot pass through the 60 mesh sieve.
b. Clean sieves by tapping on a hard surface to remove residual particles. This must
be done between sample processing.
4. Balance scale to nearest mg and weigh empty XRF sample cup. Record the weight
(e.g. 28 mg).
5. Using a pyrex funnel tripod, transfer dust into center of sample cup.
a. Weigh and record weight of dust samples. The minimum acceptable sample is 20
mg.
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b. Seal XRF cup, containing dust sample, with another piece of mylar file. Snap/fit 26
mm ring over this assembly.
c. Record lab accession number on outer ring of cup and on side rim at finger grip
cover.
d. Clean glass funnel with compressed air.
6. Remove cover of cup containing dust sample and place cup in the Kevex XRF
7700/8000 for analysis.
a. The instrument reading in ppm is obtained.
b. Calculation:
sample weight = mg/sq. ft; ppm
no. sq. ft
For example, if: sample weight = 28 mg
XRF reading = 200 ppm
area sampled = 4 sq. ft.
28 mg = 7 mgysq. ft; 200 ppm
4sq. ft
B. XRF Analysis
The instrument configuration for the Kevex Delta Analyst Energy Dispersive X-ray
spectrometer is:
1. Kevex Analyst 770/8000 Excitation/Detection Subsystem:
1. X-ray tube: Kevex high output rhodium anode
2. Power supply: Kevex 60 xC, 3.3 mA.
3. Detector/oyostat: Kevex Quantum - UTW lithium, drifted silicon.
2. Kevex Delta Analyzer:
1. Computer mainframe: Digital Equipment Corp, PDP 11/73
2. Computer software: Kevex XRF Toolbox n, Version 4.14
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3. Disk drives: Iomega Bernoulli box, dual drives, 10 MB
4. Pulse processor: Kevex 4460
5. Energy to digital converter: Kevex 5230
3. Operating conditions:
1. Excitation mode: Mo secondary target with 4 mil thick Mo filter
2. Excitation conditions: 30 keV, 0.40 - 0.60 mA
3. Acquisition time: 100 livetime seconds
4. Shaping time constant: 7.5 microseconds
5. Sample chamber atmosphere: air
6. Detector collimator: Ta
4. Analytical conditions:
1. Escape peaks, but not background should be removed from all spectra.
2. The intensity ratio, defined as the integral of counts in the Pb (LA) window
divided by the integral of the counts in the Mo (KA) Compton scatter window,
should be determined for each spectrum.
3. The intensity ratios for the standards should be used to determine a linear least
squares calibration curve.
At the time of the analysis there was no established detection limit for this type of analytical
method (via Kevex). However, the lab employed a standard calibration range from 78 to
12,000 ppm Pb due to the high levels of lead in dust. No certified reference materials
suitable for testing this method were available for a large scale interlaboratory program. A
round-robin intercalibration study for dust samples is planned for May 1991.
C. AAS Analysis
1. Glassware Supplies and Equipment:
a. Griffin beakers: glass 100 ml, graduated
b. Rasks, Class A, volumetric 25 ml, 50 ml, 100 ml, 200 ml, 1 liter, and 2 liter
c. Micro funnels, polypropylene, 24 mm top I.D. 4.5 mm stem diameter (Bel-Art
#14683-0024)
d. Test tubes: 17 x 100 mm polypropylene, round bottom test tubes: with caps
(Falcon #2059)
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e. Watch glasses: pyrex, 75 mm diameter
f. Filter paper, Whatman #42, 5.5 cm. diameter
g. Pipettes, Class A, volumetric: 2.0 ml, 5.0 ml, 6.0 ml, 10.0 ml, 15.0, and 20.0 ml
h. Pipettes, graduated, 2 ml and 5 ml
i. Cylinders, pyrex, graduated: 25 ml, 100 ml and 500 ml
j. Analytical Balance: 4-Place, Mettler AE240
k. Hotplates
1. Atomic Absorption Flame Spectrophotometer, Perkin Elmer 3030B
m. Deionized water: Hydro Service Ultrapure Water System
n. Fume Hood
2. Reagents:
a. 7 M Nitric Acid (prepared from Baker Analyzed Reagent)
b. 1 M Nitric Acid
3. Standards
a. "Stock" Standard (100 ppm lead) 20 ml of Varian Techtron Lead Standard (1000
ppm) diluted to 200 ml with 1M HNO3
4. Working Standards (6):
Working Standard
(ppm)
2.0
5.0
10.0
15.0
20.0
Stock
ml of 100 ppm
2
5
10
15
20
Total Volume
qs with 1M HNO3
100
100
100
100
100
A 0.6 ppm "working" standard is prepared with 6 ml of
10.0 ppm standard, diluted to 100 ml with 1 M HNO3
5. Label, date and initial all solutions.
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6. Sample:
Dust samples received from the "Lead in Soil Project" for AAS analysis are in XRF cups
(SOMAR), covered with mylar film. They were previously analyzed by XRF 700/8000.
For the most part, sample weight is well below 100 mg.
7. Control and Blanks:
Two NBS #1579 (11.87% Pb) controls and two total reagent blanks are included in every
group of 25 samples.
8. Procedure:
a. Preparation of Samples for Acid Digestion:
1) Acid washing of glassware: All glassware must be acid washed prior to use.
Soak for 24 hours in 30% v/v nitric acid/deionized water, rinse with deionized
water. Glassware must be oven-dried and cooled to room
temperature prior to use.
2) Label beaker with sample number, tare beaker on a calibrated 4-place analytical
balance.
3) Transfer dust sample from XRF cup into tared beaker:
a) Small quantity dust sample: Transfer completely as possible. Some dust
adhers to the Myler film and cannot be transferred.
b) Large quanity dust sample; If quanity is sufficient, transfer, weigh and
analyze in duplicate for precision check.
4) Weigh sample and record weight on form provided. One run constitutes
approximately 25 samples.
b. Hot Nitric Acid Digestion:
1) To each sample in the 100 ml beaker, add 25 ml 7 M nitric acid, washing down
the dust from the sides of beaker.
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2) Cover each sample with a watchglass and place beakers on hotplate, at 120
degrees C, for two hours. This operation must be performed in a fume hood.
3) Remove beakers from hotplate and allow to cool.
4) Transfer samples to 25 ml or 50 ml Class A volumetric flasks, depending upon
the weight of the sample. Rinse beaker and watchglass with a small amount of
1 M nitric acid and transfer to flask. Repeat rinse procedure at least three times.
Dilute to volume with 1 M nitric acid. Stopper flasks and mix well.
5) Filter the samples through Whatman #42 filter paper, using polypropylene micro
funnels, into new labeled Falcon test tubes. Cap the tubes. The samples are
ready for AA analysis.
9. Perkin Elmer 3030B Flame Parameters:
1. ELEMENT: PB WAVELENGTH (NM) 283.3 SLIT 0.7
2. FLAME: AIR-ACETYLENE, OXIDIZING (LEAN, BLUE)
3. CHARCONC: 0.45 SENS. CHECK (MG/L) : 20.0 LINEAR TO (MG/L) 20.0
Settings:
1. TECHNIQUE: AA
2. LAMP CURRENT (MA), 10
3. SIGNAL PROCESSING HOLD
4. CALIBRATION LINEAR
5. NOMINAL WEIGHT 1.0
6. STATISTIC SINGLE READING
7. TIME (SECOND) 5.0 *
8. READ DELAY (SECONDS) O.O
9. SCREEN FORMAT BASIC DATA
10. PRINTER: OFF
11. RECORDER SIGNAL 0.2 CONT ABS
12. RECORDER EXP: 1000
13. SI: 20.0
14. S2: 15.0
15. S3: 10.0
16. S4: 5.0
17. S5: 2.0
18. S6: 0.6
19. S7:
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20. S8:
21. RSLP:
Computer 1MS286 used in conjunction with the Perkin Elmer 3030B. Results obtained in
percent; then convened ppm. Results are reported in both units.
V. Baltimore Handwipe Sampling
A. Purpose
The purpose of the testing is to detect
during the clinic visit. During the
hand area. During the winter samplin
Elbow wipes were also obtained durin
negatives due to hand washing.
B. Materials
- wipes
- disposable gloves
- plastic bags
- labels
C. Procedure
At the opening of each box of gloves
The investigator wears disposable gloyes.
gloved hands using three wipes per hajnd.
the sample surface folded inward and
ead levels on children's hands. Sampling occurs
summer sampling period, samples are obtained from the
, samples are obtained only from the hand area.
the initial summer sampling to eliminate false
r Wash-a-bye baby Wipes, a blank control is obtained.
The investigators wipe all surfaces of their own
These six wipes are placed in a plastic bag with
abeled as blank with the test date.
For each child to be sampled, the investigator identifies the child and obtains the ID number
that the child has been assigned and dons a new pair of gloves.
For hand levels, the investigator wipes the child's hand on all surfaces using three wipes per
hand. Each wipe is applied to all hand surfaces, up to and including the wrist A total of six
wipes are used per child per sampling. The six wipes are then be placed in a single plastic
bag with the subject's ID number as follows:
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C_
Sampling of the elbow area also requires three wipes per elbow. Each wipe is be applied to
the entire posterior elbow and two inches up and down the arm. All six wipes are placed in a
single plastic bag and labeled as follows using the subject's ID number:
88 E _
At the end of the sampling period, all bags of samples are collected and transported to the
analysis lab.
VI. Baltimore Handwipe Analysis (Protocol A)
(NOTE: Protocol A was used for biological screens #1 and 2. Start Protocol B on 1/90).
A. PROCEDURE
1. Label 800 ml Acid washed beakers (2-800 ml beakers per sample)
2. Put 6 handwipes into each of the first set of beakers (wear gloves).
3. Pipet 1 ml of the solution standards onto the handwipes in beaker. We use four
different solution standards: 6 pg/ml
lOpg/ml
20 pg/ml
100 pg/ml
The solution standards were made from a lead reference solution (1000 ppm + 1%)
supplied by Fisher Scientific Co.
4. Measure 200 ml of acid into a graduate cylinder and carefully pour into handwipes in
the beaker (we used 2 different concentrations of Nitric acid, IN & 7N).
5. Cover beaker with a watch glass and allow to set for 2 hours (for extraction of Pb) at
room temperature.
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6. After 2 hours pour the contents of the beaker into a funnel placed on the
corresponding 800 ml beaker.
7. Rinse the first beaker with 100 ml of acid and pour into funnel in 2nd beaker.
8. Wring out the wad of handwipes into the funnel.
9. Remove the funnel and handwipes from the 2nd beaker and evaporate the 300 ml of
acid on a hotplate (be careful not to let the residue in the beaker burn) set at ~250°C.
10. After the acid evaporates remove the beaker from the hotplate and turn down the
hotplate to ~100°C.
11. Using a pipet, rinse down the sides of the beaker with ~10-15 ml of 10% HNO3.
12. Place beaker back on hotplate and allow the acid to evaporate to ~3 ml (swirl beaker
to loosen the residue on bottom of beaker).
13. Set beaker aside to cool (~3 ml acid left on beaker).
14. Pour the contents of beaker into a 10 ml graduated mixing cylinder.
15. Make up to 10 ml total volume with 10% HNO3 used to rinse beaker.
16. Shake cylinder to mix the acid.
17. Pour acid into plastic 15 ml tube.
18. Submit to analytical for A.A.
B. Baltimore Handwipe Analysis (Protocol B)
(NOTE: Protocol B was used for biological screen #3. Change date 1/90).
1. Place each sample in a labeled, acid-washed 800 ml beaker.
2. To each sample, add 100 ml of 1 M nitric acid prepared with deionized water.
3. Swirl each sample for 10 seconds.
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4. Cover each sample with a watchglass and allow it to extract at room temperature for 2
hours.
5. Decant the acid solution from the handwipes into a labeled, acid-washed 250 ml
beaker.
6. Add 50 ml of 1 M nitric acid to the handwipes in the 800 ml beaker.
7. Swirl the sample for 10 seconds.
8. Decant the acid solution into the same 250 ml beaker to composit the acid rinse.
9. Repeat steps 6, 7 and 8 a second time for a total acid solution of about 200 ml.
10. Cover the samples with a watchglass which is elevated above the beaker rim with
glass hooks. (The watchglass must be elevated to prevent "bumping" of the sample
during evaporation).
11. Place the samples on the hotplate at about 250 ° C.
12. Evaporate the samples to dryness.
13. Add about 3-5 ml of 1 M nitric acid to each sample, rinsing the watchglass and the
sides of the beaker.
14. Heat the samples gently on a hotplate at 120-150 ° C to redissolve lead.
15. Filter samples to remove undissolved material, using the following procedures.
Filtration apparatus:
Whatman #54 filter paper
Glass funnels
50 ml labeled, acid washed beakers
IMHNOj
a) Fold filter paper and place in runnel.
Rinse the filter paper and funnel with 1M HNO3 over a 50 ml beaker, and discard the
rinse.
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b) Filter each sample into a 50 ml beaker, rinsing the 250 ml beaker filter paper, and
funnel with 1M HNO3.
c) Reduce the volume of acid in the 50 ml beaker to about 5 ml on a hotplate at about
250 ° C.
16. Transfer the sample with 3 rinses of 1 M nitric acid to a labeled, acid-washed 10 ml
graduated tube (Corning Cat. 2972, tolerance + 0.1 ml) and make up to volume with
1 M nitric acid.
17. Shake each sample very well. Transfer each sample to a new, labeled polystyrene test
tube with screw cap.
18. The samples are then submitted to the AAS lab. Results are reported in total
pg/sample.
VIL Baltimore Paint Chip Sampling
A. Visually evaluate the residence for evidence of peeled, chipped, cracked paint on all
surfaces.
B. Identify sample locations of painted surfaces that are peeling, chipped or cracked.
C. Collect paint samples using the sharp edge of a small knife blade to scrape all layers of
the suspect material down to the substrate. The area sampled will equal a diameter of 2.0
inches.
D. Place the sampled material in a previously unused sampling paper envelope and seal all
edges of the envelope.
£. Mark the sample envelope with the property identification number, sample code and
sample number.
F. Return samples to the office.
G. Record sample information on index card file.
H. Deliver samples to lab for analysis.
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I. Report sample results to Lead In Soil personnel using the modem.
J. Samples which contain 0.06% lead will be positive for lead in this study.
K. Lead In Soil personnel record sample results on main property file.
L. Residences which do not reflect sample results of 0.06% lead in the paint chips sampled
will not be scheduled for paint stabilization.
VIII. Baltimore Paint Chip Analysis
A. Using the mortar & pestle method:
1. Paint chips delivered to the lab.
2. Samples must be logged in on the Lead in Soil Processing Sheets. The date, the time,
the total number of samples brought by the collector, and all the information listed on
the sample bag should be written on this sheet The information listed on the
bag will include the sample identification number, the address and particular area
from which the sample was taken needs to be written on the Lead hi Soil Processii
Sheet Example:
Date received: 3/22/89
Time: 12:30 p.m.
Total Number of Samples Received From: 135 from Ms. Merrill Brophy
Sample Identification Number: #590316535
Address: 2092 W. Preston Street
Area: Side of Front Door
3. The paint samples then need to be written up on the XRF Run Sheets. Identification
number is assigned. The sample is then given an analysis number by the analyst
The number given to the sample is used only as a means to identify a particular
sample for analysis. The samples should be written in consecutive sequence.
Example:
The last sample analyzed was number 0439, then the next paint chips sample
should be numbered 0440.
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4. Specimen containers and XRF sample cups are to be prepared before samples can be
processed.
a. Label specimen containers - Include the date, the analysis number, and the
samples's identification number.
b. Label XRF sample cups - Include only the analysis (i.e. cup) number only.
5. Mortar & pestle should always be clean.
6. Place paint chips into mortar and use the pestle to crush the sample. Continue to
crush the sample until a homogeneous mixture is attained. Gloves and respirators
must be worn.
7. Use a spoon or spatula to place the sample into a corresponding XRF sample cup,
then seal the cup with mylar film and a ring.
8. Before next sample is crushed, the mortar and pestle should be wiped clean. Wipe the
mortar and pestle with a clean paper towel, then wash them with distilled water and
dry them with a clean paper towel. This process should be done after each sample.
9. Once all samples have completed steps 1 - 7, the samples are now ready for analysis.
10. Analyzed sample results are recorded onto XRF Run Sheets in ppm's..
B. Using Electric Mill Method
1. Paint chips delivered to the lab.
2. Samples must be logged in on the Lead in Soil Processing Sheets. The date, the time,
the total number of samples brought by the collector, and all the information listed on
the sample bag should be written on this sheet The information listed on die sample
bag will include the sample's identification number, the site address and particular are
from which the sample was taken needs to be written on the Lead in Soil Processing
Sheet Example:
Date received: 3/30/89
Time: 12:30 p.m.
Total number of Samples Received From: 135 from Ms. Merrill Brophy
Sample Identification Number: #590316521
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Address: 2092 W. Preston Street
Area: Side of Front Door
3. The paint chip samples identification numbers are recorded on the XRF Run Sheets.
The sample is then assigned an analysis number by the analyst. The number given to
the sample by the analyst is used only as a means to identify a particular sample for
analysis. The samples should be written in consecutive sequence. Example:
The last sample analyzed was number 0439, then the paint chip sample should be
numbered 0440.
4. Specimen containers and XRF sample cups are to be prepared before sample can be
processed.
a. Label specimen containers - Include the date, the analysis number, and the
sample's identification number.
b. Label XRF sample cups - Include analysis number only.
5. Electric mill should always be clean.
6. Electrical grinding must always be done under the hood. Gloves and respirators must
be worn.
a. Place paint chip samples into the electric mill.
b. Turn electric mill on for approximately 3 minutes.
c. Turn grinder off after 3 minutes, wait for the dust to settle, remove lid and check
to see if a homogeneous mixture was attained.
7. Use a spoon or spatula to place the sample into a corresponding XRF sample cup,
then seal the cup with mylar film and a ring.
8. Before the next sample can be processed, the electric mill should be cleaned. Wipe
the electric mill with a clean paper towel inside and out, dampen another paper towel
and clean the mill very well, and then dry the electric mill with another clean, dry
paper towel. This process should be done between each sample.
9. Once all samples have completed steps 1 - 7, the samples are now ready for analysis.
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10. Analyzed sample results are recorded onto XRF Run Sheets in ppm's.
DC. Baltimore Paint Stabilization
A. Before-preparation practices:
1. Prior to preparation, occupants shall be notified of starting date and expected date of
completion. They shall be instructed to remove all movable objects from the work
area and be informed about the proper method of entrance to and egress from the
property. Signs of heavy cardboard shall be posted at each property, in a location
clearly visible to passersby, at least seven days prior to the start of work.
2. Windows and doors in the work area shall be taped using duct tape or equivalent
water proof tape to seal out dust for the duration of the work. Six mil thick plastic
should be installed on vertical surfaces where wet scraping occurs.
3. All workers will be required to change into appropriate work clothes, including shoes,
upon arrival at the work site. Remove work clothing before leaving work site. Each
worker will be required to wear a half-mask air purifying respirator equipped with
high efficiency filters while in the work area. Smoking, eating, and drinking will
not be permitted in the work area. The contractor will provide water, a dressing
room, washroom and toilet facilities for use of his employees.
4. Blood will be taken from the workers and tested prior to starting the project, at two
months and at the conclusion of the project
B. Complete preparation of exterior surfaces containing cracking, chipping, peeling or
chalking lead based paint includes removal of deteriorated paint, HEP A (high efficiency
particle air) vacuum cleaning, washing and rinsing.
1. Methods of removal are limited to wet scraping in which the surface being worked on
is kept constantly wet using a water spray.
2. Removal includes complete collection and disposal of all resulting debris and dust
3. Cleanup shall include HEP A vacuuming of all surfaces to remove dust; if this is not
feasible, wet methods may be used, including wet sweeping, shovelling, and/or
brushing.
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4. All debris, including used sealing tape, torn or damaged drop cloths, filters, and
disposable clothing shall be disposed of according to hazardous waste regulations.
Waste shall be documented by type, quantity, and disposal site.
C. Minimum preparation, washing and rinsing to remove dust and dirt, of surfaces adjacent
to those treated above shall be done as necessary, to match those surfaces.
D. Repainting can begin after the site has been inspected and approved and shall begin
within 48 hours of completion of surface preparation. The contractor shall provide all
labor, materials, equipment, and services necessary for satisfactory application of field
painting.
1. All caulking shall be done as directed by the Project Manager. Caulk shall be a one
part 100% liquid polymer, acrylic base compound, non-sagging, non-staining, and of
gun consistency.
2. All paint shall be applied using a brush or roller. All surfaces being repainted shall
receive one coat of primer and two finish coats. Paint shall be unscarred and
completely integral. Sufficient drying time must be allowed between coats to satisfy
the manufacturer's requirements. Paint shall be a high quality latex based
composed of a primer and an exterior finish, and shall have a lead content of
more than 0.06%.
3. Upon completion of the work, all paint spots shall be removed from walls, glass and
other surfaces. All rubbish and accumulated materials shall be removed and area
must be left in a clean, orderly and acceptable condition.
E. The contractor may, with approval of the project manager, choose to cover such items as
window frames, porch eaves and door frames with 0.032 inch thick, alloy 3004 - H 134
aluminum sheets as an alternate to scraping and repainting them.
1. Prior to starting work, all windows and doors of the affected structure shall be taped
to seal out any dust
2. Covering shall be formed on site to produce a close fitting cover with smooth bends,
close joints, and a generally neat appearance.
3. Fasteners shall be spaced in accordance with good practice, hidden where possible.
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4. Joints at comers and at edges where aluminum abuts masonry shall be neatly made
and neatly and fully caulked. Caulk shall be one part 100% liquid polymer, acrylic
base compound, non-sagging, non-staining, gun consistency,
5. After completion of work and at the end of the day, all resulting debris and dust shall
be removed using a HEPA vacuum cleaner and disposed of according to regulations.
X. Baltimore Drinking Water Sampling
A. Residents are notified that water must not be turned on prior to the Environmental Health
Aide sampling the system on the sampling day.
B. Do not shut off water flow valve to the sink fixture (which would prevent use of the
system prior to first draw) as this may introduce lead corrosion products into the sample.
C. Morning first draw is collected from a cold water tap which had not been used for 8-18
hours. Determine if water was used prior to sample collection. If water was used, state
the use in the remarks on the sample collection form.
D. Water samples are collected from each household faucet in 250 ml cubitainers.
E. Water samples are preserved on site with 5 ml of nitric acid per liter.
F. Water tap is closed after filling each sample container to prevent loss of product and to
ensure representative collections.
G. Keep samples cool (4 ° C) after collection prior to analysis.
XL Baltimore Drinking Water Analysis
A. Reference: Method 239.2 (Atomic Absorption, furnace technique) EPA - 600/4-79-020
Optimum Concentration Range: 5-100 ug/L
Detection Limit: 1 pg/L
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B. Application
Tests for lead are carried out using the graphite furnace atomic absorption technique as
described herein. Samples, blanks, quality control, replicate, and spike test solutions are
prepared as described and placed in trays for automatic sampling (see Quality Assurance
Plan). This instrument setup and analysis steps are performed using the parameters defined.
C. Preparation of Standard Solution
1. Stock lead solution: Commercially available containing 1000 mg/L (1000 ppm) of
lead.
2. Matrix modifier - Ammonium monobasic Phosphate + Magnesium Nitrate Solution:
Transfer 4 grams of NH»H2PO4 monobasic Ultrex reagent and 0.2 grams of Mg
(NO3)2, Suprapure, to a 100-mL volumetric flask and makeup to mark with deionized
distilled water (DW) containing 0.5% (v.v) HNO3.
3. Working lead solution: Dilute the stock solution to the ratios needed as calibration
standards at the time of analysis. The calibration standards and reagent blank must tx
prepared with the same acid, i.e., 0.5% (v/v) HNOj. The reagent blank (RB) use
all subsequent dilutions is prepared by diluting 5 mL cone. HNO3 to 1 L with D1
A 1-ppm solution is prepared by dilution of the 1000-ppm stock solution with
This 1-ppm solution is used to obtain calibration standards of 0, 5, 10, 25, 50, and
100 ppb lead. To obtain the calibration standards, withdraw appropriate aliquots of
the 1-ppm solution and dilute to 100 mL with RB.
D. Sample Preparation
All samples solutions for analysis are acidified in the field or in the laboratory and contain
0.5% (v/v) cone. HNO3.
Instrument Parameters for Lead Analysis
1. Drying Time and Temp: 40 sec. -120 ° C
2. Charring Time and Temp: 40 sec - 1000 ° C
3. Atomizing Time and Temp: 5 sec - 1800 ° C
4. Cleaning Tune and Temp: 5 sec - 2600 ° C
5. Cooling Time and Temp: 20 sec - 25 ° C
6. Purge Gas Atmosphere: Argon
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7. Wavelength: 283.3 nm
8. Slit: 0.7 nm
9. Tub/site: Pyro coated tube with L'vov platform
10. Matrix Modifier Setting: 5 ul
11. Sample and Standard Quantity Setting: 20 uL
12. Max power: 30
13. Background correction mode: on
14. Lamp: electrodeless discharge lamp (EDL)
Note: Parameters 1, 2, 4, and 5 use 1 sec. ramp time. Parameter 3 uses 0 sec. ramp time
and gas stop flow.
Instruments Used
1. Perkin-Elmer model 3030 Atomic Absorption Spectrophotometer with D2 Arc
Background Corrector
2. Perkin-Elmer PR-100 printer
3. HGA-300 graphite furnace
4. AS-40 Auto Sampler
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Appendix A-2: Boston Protocols for Sampling and Analysis
I. Boston Preliminary Soil Sampling
The goal of the preliminary sampling is to determine whether the soil surrounding the premise
of a potential participant contains high levels of lead For a premise to be eligible, two or
more samples must contain at least 1500 parts per million, or the mean of all the samples
must be 1500 parts per million or greater.
A total of up to five samples will be taken, which in most cases represents the four sides of
the house and a separate play area if one exists. To start, draw a rough sketch of the house
and surrounding property. Indicate areas that are paved and those with soil or grass. Label the
sides of the house F, L, R, and B, for front, left, right, and back, respectively. Right and left
are always from the perspective of standing on the sidewalk looking at the front of the house.
Take one sample from each side of the house where there is soil. If there is an area of soil
that is not directly adjacent to the house, but appears to be a potential play area, a sample
should be taken mere as well. Areas of soil that are on the same side of a house but are
separated by a porch or stairs may be sampled separately, or combined as one sample.
Sampling Instructions:
Materials needed:
Trowel
paper towels
plastic bucket
zip-lock sandwich bags
marker
labels for bag
Chain-of-custody forms
To get a representative sample, you will use a technique called "composite sampling". This
involves taking several sub-samples in an area and then mixing them together to make one
composite sample.
For areas adjacent to the house, take five sub-samples along a line parallel to the house, at a
distance of one meter from the foundation. The subsamples should be fairly evenly spaced
along the foundation for the length of that side, or as much of that side as is not paved Each
subsample should consist of scoop of soil 5 cm in diameter and 2 cm deep. Mix the five
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sub-samples together in the bucket to make the composite sample from that side of the house.
Put the composite sample in a rip-lock bag and place the identifying label on the bag. Fill out
the label, giving premise address, premise ID, and sample letter. The sample identification
number will consist of the premise number, followed by the letter corresponding to the side
of the house. If more than one sample is taken on a side, then follow the letter with a
number, for example, Fl, F2, etc. Indicate all sample locations on sketch.
For play areas that are not adjacent to the house, follow the composite sampling guidelines,
treating the area as a rectangle or a square. Take sub-samples from the four comers and the
middle of this area. Label samples from such play areas "P".
For each sample, initiate a chain-of-custody form. Between samples, wipe the trowel and
bucket with paper towels to remove any residual soil.
IL Boston Soil Sampling
SITE DESCRIPTION
General Site Description. For each location, a detailed drawing should be made that
shows the boundary of the lot, the position of the main building and any other buildings
such as storage sheds or garages, the position of the sidewalks, driveways, and other
paved areas, the position of the play areas if obvious, and the position of the areas with
exposed soil (grassy or bare) (See attachment A). Show down spouts and general
drainage patterns. Identify each soil subarea by letter or number. If a large soil area
needs to be divided into smaller patches for sampling convenience, show how this
division was made.
In addition to the diagram, briefly describe the location, including the following
information:
Type of building construction
Condition of main building
Condition of lot (debris, standing water, vegetation cover)
Nature of adjacent property
Presence and type of fence
Animals on property
Apparent use of yard (toys, sandbox, children present)
Underground utilities
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Subarea Description. For each soil subarea identified on the general diagram, draw a full
page diagram showing the approximate dimensions and position relative to the building
foundation (see Attachment A). Indicate vegetation and bare soil areas, as well as
obvious traffic patterns. Identify the category of landuse, such as roadside, property
boundary, adjacent to foundation, play area. Select an appropriate sampling scheme and
mark the sample locations on the diagram.
Sampling Schemes. The sample scheme selected for each subarea must adequately
characterize the potential exposure of children to lead in the dust from this soil. It must
identify the areas of high lead concentrations, and the general distribution pattern of lead
concentrations at the soil surface. For abatement purposes, the depth to which lead has
penetrated the soil profile must be determined. Consequently, selected the most
appropriate sampling scheme is the critical element in the site description. Several
options are offered for the best judgement of the investigator.
Line Source Pattern. This pattern can be used whenever the source of the lead is thought
to be linear, such as along a building foundation, a fencerow, a street, or beside a garage.
Draw a line parallel to the source, such as the foundation of the main building,
approximately 0.5 meters (20 inches) from the foundation. Repeat at the property
boundary if the subplot is more than three meters wide (10 ft), and add a third parallel
line between the first two if the subarea exceeds five meters (16 ft) in width. Divide each
line into segments that do not exceed 7 meters (20ft) in length. Take one composite of 5-
10 cores along each line segment A subarea, for example, that is at the side of the main
building and measures 12 X 7 meters would have three lines of two segments each. The
lines would be parallel and approximately three meters apart They would be 12 meters
long and consist of two 6 meter segments each, making a total of six samples, each being
a composite of at least five cores divided into a top 2 cm sample and a bottom 2 cm
sample.
Targeted Pattern. This method is intended to be used in conjunction with the line source
or grid patterns as a means of sampling obvious areas that would be missed by the
regular patterns. In using the targeted pattern, die investigator should select those
locations within the subarea that are likely to reflect potential exposure to lead in soil
dust These may be play areas, paths, drainage collection areas, or areas mat are likely to
contribute dust to other surfaces mat children use. Determine the number of samples to
be taken by identifying distinctive landuse characteristics (path, swingset, sandbox), and
take a composite of 5-10 cores for each sample.
Small Area Pattern. When the subarea is less than two meters in each dimension, or
when the accessible area of a larger plot is less than four square meters, a single
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composited sample may be taken if it appears that such a sample would adequately
represent the subarea.
Grid Pattern. Establish a rectangular grid of intersecting lines 2-10 meters apart, and
sample each rectangular area. For larger areas, randomly select the rectangles to be
sampled. In each rectangular area, mark three lines parallel to the longest axis, and
composite 5-10 cores along each line. Since the rectangle should not exceed four meters,
there is no need to divide the line into segments. Therefore, each rectangle should have
six samples of 5-10 composites each. Use this pattern when the subarea is generally
uniform and there is no reason to suspect large variations in lead concentrations.
When the sample sites have been located on the subarea diagram and the sample
collection is ready to proceed, locate each sample with a flag and visually confirm an
even and representative distribution of sample locations.
SAMPLE COLLECTION
The flags or other markers represent the center of the sample location for the targeted and
small area patterns. For the line source and grid patterns, the flags indicate the sampling
lines. Take at least five but not more than ten cores randomly selected from within the
sampling area of the targeted and small area sampling patterns. For the line source
sampling pattern, select a random location on each line and take subsamples within a 2*
by 2' square area. Take these subsamples from the four corners and the middle of the
square with the middle point being on the line. When the line exceeds 7 meters and is
broken into segments, take a composited sample in the above manner on each segment
The cores make a composite identified as a single sample. A sample record sheet is used
to record information about the composite.
The corer should be clean and free of lead contamination. Vegetation and debris can be
removed at the point of insertion, but do not remove any soil or decayed litter. The corer
should be driven into the ground to a depth of at least 10 cm, 15 cm if possible. If the
10 cm depth cannot reached, the corer should be extracted and cleaned, and another
attempt made nearby. If the second attempt does not permit a 10 cm core, the sample
should be taken as deep as possible, and the maximum depth of penetration noted on the
sample record sheet Every effort should be made to take all cores of a composited
sample at the same depth.
The cores of each plot should be examined for debris, artifacts, and any other evidence of
recent soil disturbance. These should be noted on the subarea description sheet, as should
a brief description of the soil color and soil type.
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For each sample location, the top 2 cm segment of each of the cores are composited into
one sample, and the bottom 2 cm segment combined into a second. For the surface
segment, debris and leafy vegetation should not be included with the sample. However,
no soil or decomposed litter should be removed, as this is the most critical part of the soil
sample and is likely to be the highest in lead concentration.
The soil core segments should be composited in scalable polyethylene containers suitable
for prevention of contamination and loss of the sample. The sample identification number
should be placed on the container and the sample record sheet After each sample
composite, the corer should be cleaned by reinsertion in the next sampling area. Store the
composited soil sample at ambient temperature until returned to the lab.
A field blank should be taken for each sample crew day. This is normally done by taking
a sample container with clean quartz sand into the field, opening it to expose the
container for a period of time representing normal sample procedures, then returning the
container to the lab in the same manner as other soil samples. The purpose of the field
blank is to detect accidental or incidental contamination during the sampling process.
SAMPLING HANDLING AND STORAGE
The sample containers should be sealed to prevent loss or contamination of the sample.
Shipping containers should also be airtight Storage should be in a cool, dry location.
RECORD-KEEPING AND SAMPLE CUSTODY
Soil sample records for each location consist of a location diagram and description, a plot
diagram for each distinct soil plot, and sample record sheet for each sample in a plot
The sample record sheets should also contain space for chain-of-custody documentation
(See Attachment B).
Samples should be sequentially numbered within each subarea. Each location diagram,
subarea description, and sample record sheet should bear all sample numbers and the
signature of the person responsible for verifying the quality of the information collected
This signature certifies that there has been no misuse of the sample protocol, no mistake
in recording the information, and that the information is sufficient to clearly identify these
samples for comparison with other types of samples taken at the same location, such as
street dust, house dust, house paint, blood, and hand dust These documents also establish
the chain of custody required for the Quality Assurance Plan.
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When the sample is delivered to the laboratory, custody is relinquished by the field
investigator and received by the lab supervisor by signatures on the sample record form.
IE. Boston Soil Analysis
METHOD OF ANALYSIS
Three methods of analysis have been considered. They are Atomic Absorption
Spectroscopy (AAS), Inductively Coupled Plasma Emission Spectroscopy (ICP), and X-
Ray Fluorescence (XRF). The XRF method is the approved method for routine analyses
whereas the AAS method should be used for standardization.
Sample Definition. The representative urban soil sample is defined as the soil from 0-2
cm depth that passes a 250 um stainless steel sieve. This fraction is comprised of small
particles, and the concentration of lead believed to be closely related to that of particles
on the hands of children. The fraction is also homogenous enough to allow reliable
analysis by X-Ray fluorescence.
Sample Preparation.Sample preparation requires that the sample be air dried and separai
by particle size before being digested by wet chemistry. Drying is done at room
temperature overnight, or until the sample can be easily disaggregated by hand or with
rolling pin. The full sample should be brought to complete disaggregation by passing
through a 2 mm sieve, using the fingers or a stainless steel tool to crush the larger soil
particles. Material larger than 2 mm should be discarded. Soil should not be milled tc
fine powder with a mortar and pestle or any other grinding device.
The fraction that passes the 2 mm sieve is now called the total soil fraction. A portior
this sample is retained for possible reference analysis, but the larger fraction is passed
through a #60 mesh sieve (250 um), giving a fine soil fraction identified as the "Urbar
Soil Sample." The portion that does not pass the #60 mesh sieve should be discarded,
only the total soil fraction (<2 mm) and the fine soil fraction will be analyzed.
About 5-10% of the retained total soil samples should be analyzed. An aliquot is groi
so that it all passes a #60 mesh (250 um) sieve, mixed well and analyzed. Grinding i
necessary to provide low/appropriate variance in XRF analysis.
During the processing of the sample, it should be remembered that small soil particles
may individually be as high as 50,000 ug Pb/g, and paint fragments as high as 300.0C
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pg/g. Care should be taken to clean equipment between samples. The sieves may be
cleaned by tapping on a hard surface to remove residual particles, or any other dry
method. Wet washing is not recommended as this will interfere with the size calibration.
Care should also be taken to thoroughly homogenize the separated sample before
removing the aliquot for analysis. Shaking will cause separation. Tumbling or stirring is
recommended.
Atomic Absorption Spectroscopy (To be used for primary standards)
Wet Digestion. The extraction procedure used for solubilizing soil lead is critical to
the interpretation of the results of the Superfund Soil Lead Abatement Demonstration
Projects. Even in the absence of analytical errors, the data may not represent the
same lead concentrations from sample to sample unless the correct extraction
procedure is used. The method selected here does not represent the total extraction of
lead, but the breakdown of the organic material and the leaching of lead from the
inorganic soil fraction. The methods measure total non-matrix soil lead, because no
other extractable fraction has been experimentally shown to measure bioavailable, or
non-HF extractable, soil lead. Hot HNO3 has been repeatedly shown to extract total
non-matrix soil lead, or at least >95% of soil lead, compared to a total soil dissolution
method (HF). The 1.0 N HNO3 cold shake method has been shown to extract as much
lead as the hot HNO3 extract, except for unpolluted soils where a higher fraction of
the total soil lead is within the matrix of soil particles.
The sample should be oven dried at 105°C for 24 hours or until a constant weight is
achieved. The aliquot should be placed in a 150 ml beaker and covered with a watch
glass. Class A borosilicate glassware and stainless steel tools should be used
throughout the sample processing. Low density conventional polyethylene containers
may be used to store the solution prior to analysis.
An aliquot of 1 g soil is normally considered representative of the whole sample if
the soil is well mixed. Prior to removing the aliquot, the sample should be stirred
with a spatula or rod. Shaking the container can cause the sample to separate by
particle size.
Hot HNO, Extraction. Add 50 ml 7N HNO3, cover and digest gently at 95°C far 2
hours, stirring occasionally. If excessive foaming occurs, remove from the heat «
periodically until foaming subsides. Maintain at least 25 ml in the beaker by
adding 7N HNO3 as necessary.
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Cool and dilute with 10 ml IN HNO3. Filter through Whatman No. 42 filter paper
into a volumetric flask. Rinse filter and labware with IN HNO3, and dilute to
volume.
Cold HN(X Extraction. Weight the 1 g aliquot into a 4 oz. urinalysis cup. Add 50
mL 1.0 N HNO3 to each cup. Screw the lid on tightly and place on a reciprocal
shaker. Adjust the speed of the shaker to maintain a suspension of the soil
particles. Shake for one hour, then filter through a Whatman 111-V filter. Rinse
with 1.0 N HNO3. Dilute to standard volume.
Analysis. Analysis by flame AAS should be at 283.3 nm, with background
correction. Working standards should be prepared fresh daily, in the range of 2-50
ug/g, in a 1.0 N HNO3 matrix.
XRF Analysis
Approximately 2 g of loose soil sample are poured into sample cups (Somar Labs,
Inc., Cat No. 340), fitted with windows of 1/4 mil thick X-ray polypropylene film
(Chemplex Industries, Inc., Cat No. 425). The sample cup should be at least half full.
The sample cup is sealed with a sheet of microporous film (Spex Industries, Inc., Cat
No. 352A) held in place by the snap-on sample cup cap. The exact weight of the
sample is not important, but should be in the range of 2-6 g.
The instrument configuration for the Kevex Delta Analyst Energy Dispersive X-ray
Spectrometer is:
1. Kevex Analyst 770 Excitation/Detection Subsystem:
a. X-ray tube: Kevex high output rhodium anode
b. Power supply: Kevex 60 kV, 3.3 mA.
c. Detector/cryostat: Kevex Quantum - UTW lithium, drifted silicon. 165 eV
FWHM resolution at 5.9 KeV.
2. Kevex Delta Analyzer:
a. Computer mainframe: Digital Equipment Corporation, PDF 11/73
b. Computer software: Kevex XRF Toolbox n, Version 4.14
c. Disk drives: Iomega Bernoullik box, dual drives, 10 MB
d. Pulse processor: Kevex 4460
e. Energy to digital converter Kevex 5230
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3. Operating Conditions:
a. Excitation mode: Mo secondary target with 4 mil thick Mo filter.
b. Excitation conditions: 30 kV, 1.60 mA
c. Acquisition time: 300 livetime seconds
d. Shaping time constant: 7.5 microseconds
e. Sample chamber atmosphere: air
f. Detector collimator: Ta
4. Analytical Conditions:
a. Escape peaks, but not background be removed from all spectra,
b. The intensity ratio, defined as the integral of counts in the Pb (LA) window
divided by die integral of the counts in the Mo (KA) Comptom scatter window,
should be determined for each spectrum
c. The intensity ratios for the standards should be used to determine a linear least
squares calibration curve.
The acquisition time (3c) may be reduced at the discretion of the lab supervisor.
QA/OC. By blind insertion into the sample stream (where possible), the QA/QC officer
will provide the following blanks at the indicated frequency. At the discretion of the
project director, the field team will collect one blank per day by carrying a sample of
clean quartz sand into the field in a normal sample container. The sample container will
be opened and exposed during the collection of one sample, then closed and returned to
the lab. The field blank can be split into two aliquots. One aliquot, the field blank, can
be analyzed directly with no further treatment The second aliquot (the sample blank) can
be analyzed after it has passed through the sample stream (except sewing). The field
blank represented contamination added in the field, the sample blank represents
contamination added in the field and during storage and sample preparation.
A project standard soil sample will be prepared and distributed at the beginning of the
study. This will be used as a lab control. For XRF analysis, there is no need for a
reagent blank.
Field blank I/field sampling day
Sample blank I/field sampling day
Lab control 1/20 samples
Reagent blank 3/reagent batch
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Additionally, split sample (duplicate) analyses and spiked samples will be determined as
follows:
Split soil 1/20 samples
Spiked soil 1/20 samples
The spiked soil samples will be prepared by mixing dried and sieved soil of known
concentration with the sample. Spiked soil samples may be used at the discretion of the
project director. Additional split soil samples will be sent to a designated QA/QC
laboratory for analysis using the hot HNO3 method, one for each 40 samples.
An inteiiaboratory comparison, similar to the soil pilot study, will be conducted during
each six month period, with 10-20 samples from each laboratory, including the QA/QC
lab. These samples will be dried, but not sieved.
IV. Boston Recontamination of Soil • Sampling
For each property that was in the project after the baseline blood sample, soil samples need to
be taken to check for changes in soil lead. Some of the properties have been abated, and
others have not You will get a sampling pattern for each property. Recontamination samples
will be taken at every other location where a detailed sample was taken before. In other
words, you will take half the number of samples. The locations which need to be sampled
will be highlighted on the map. Locations which are not highlighted can be ignored.
At each location on the map, there will be a number and a little box like this O .
Sometimes the box will be on a line, like this D . The box is where the sample should be
taken. It represents an area of about two square feet At each location, get as close as you can
to where the box appears on the map, and take five surface scoops of soil in an area of about
two square feet. Mix these samples in the plastic container (sound familiar?) and put about a
1/2 cup of the mixed soil in the sample bag.
The sample bags can be written on using an indelible marker. Put the address, premid, and
sample number on each bag. You can do these in advance to save time in the field. Please
use a separate paper bag and chain-of-custody form for each property. If you are unable to
take a sample or if there is some other problem with a property, please write a note separate
from the chain-of-custody form and put it in the paper bag with the samples.
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Samples should be numbered using the number on the sample plan, with the addition of the
letters "RE". For example, RE2, RE4, RE6, etc.
V. Boston Household Dust Sampling1
For this study, the household dust samples are defined as the samples that are most likely to
come into contact with a child's hands during indoor activity. This would include dust on
upfacing surfaces accessible to die child such as bare floors, carpets, window sills and wells,
furniture, as well as dust on toys and other objects likely to be handled by children.
Dust sampling has two components that are important to interpreting lead exposure: the
concentration of lead in the dust and the amount of dust or loading on the surface. The
concentration of lead in dust appears to be closely related to the amount of lead on children's
hands whereas the amount of dust on surfaces is an indicator of the importance of this route
of human exposure.
Dust Collection and Sample Handling
There is no standard procedure for collecting dust samples. The following protocol was
decided upon after reviewing other available methods (such as the personal air pump) and
finding them inadequate. The dust sampling method chosen was the Sirchee-Spittler modified
dust buster. We believe that it is the best method for collecting numerous household dust
samples within a reasonable amount of sampling time. Other necessary equipment to conduct
the sampling are a ruler to measure the sampling area, a 25" by 25" template for designating
the floor sampling area, paper envelopes to which the dust samples will be transferred, tape to
seal the envelopes, and a cylinder of compressed air for cleaning the sample collection screen.
Before collection, make certain that the Sirchee-Spittler modified dust buster is fully charged.
You can tell this by running the dust buster for a few seconds and listening for a high pitched
sound from the motor. Another way to monitor the charge in the dust buster is to keep track
of the number of samples taken on a change. A maximum of 18 samples (roughly three
households) should be taken on one charge. Also, when starting a sampling round in a
household make sure that the sample collection screen is clean. Use the compressed air
cylinder to blow the screen clean. v>
1 Parts of this protocol were adapted from Dr. Tom Spittler's 12/88 protocol "Instructions
for Operation and Maintenance of Sirchee-Spittler Hand-Held Dust Vacuum Units".
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Seven dust samples should be taken in each LFK household from each of the following
locations: entry floor (i.e. right inside the front door of the house or apartment), LFK child's
bedroom window well and floor, kitchen window well and floor, and living room window
well and floor. You may choose which window to sample in a room. The floor samples
should be taken roughly from the center of the room. Sometimes it will not be possible to
get all six samples in a household because of windows that are nailed shut, obstructed by air
conditioners, etc. In these instances, obtain as many samples as possible from the designated
locations.
Once the individual sampling locations are decided upon, the size of the sampling area must
be measured. For the window wells, measure the sampling area with a ruler. For the floors,
set down the 25" x 25" template. If the floor is very clean, it may be necessary to vacuum a
surface area larger than 25" x 25". In these cases, vacuum an area whose size is double or
triple the template area. Be sure to obtain an amount of dust that is adequate for analysis (at
least 5 mg).
The sampling sequence should be as follows: Collect the bedroom, kitchen and living room
floor samples first. Then, collect the floor sample from the entry way. Finally, collect the
window well samples.
To collect a dust sample, switch on the dust buster and vacuum the designated area with back
and forth strokes about 1-2 inches in width. The vacuum is most efficient if the head is held
parallel to the ground and titled about 5 degrees in the direction of the motion. When the
surface has been vacuumed, keep your finger on the switch while raising the vacuum to an
upright position. The constant air flow will prevent loss of dust from the filter before it is in
an upright position. Switch off the power and carefully remove the vacuum head without
tilting it significantly. Reach in and remove the filter screen with a gentle clockwise motion.
Transfer the dust sample to the paper envelope in the following way. Empty the contents of
the filter screen into the paper envelope. Tap the envelope to cause the sample to collect in
one end. Next, tap the filter ring several times into the open envelope on a hard surface.
Tap the dust to the bottom of the envelope and then seal the envelope and fold over 1/2 inch
of the top of the envelope and crease carefully. Tape the folded part of the envelope down
with at least a 10 inch long piece of Scotch tape. Each envelope should be labelled with the
following information: LFK child's name, LFK number, sample location (Le. bedroom
window well) and size of sample area. It would be best if these envelopes and labels were
prepared beforehand. Remember to handle the dust containing envelopes carefully; keep them
upright in an envelope box. We want to avoid any loss of dust from the envelopes.
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Replace the filter screen with a counterclockwise motion, attach the vacuum head and collect
the other samples in the household using the same method. When you are finished sampling
a household, clean out the filter screen and the vacuum head with a blast of compressed air.
VI. Boston Dust Analysis
SCOPE AND APPLICATION
Lead in household dust may be determined by energy dispersive X-ray fluorescence (XRF)
spectrometry. This method is simple, rapid, and applicable to Lead in various matrices with
little or no sample preparation (i.e., digestion is not required prior to analysis).
Detection limits, sensitivity, and optimum ranges of the metals will vary with regard to
sample matrix as well as the model of XRF instrument utilized.
This method is applicable for use by Region I ESD and ESAT staff for performing XRF
screening analyses in lead in house dust samples as part of the LFK Demonstration Project.
SUMMARY OF METHOD
This method may be used for the quantitative analysis of house dust samples for lead. The
dust sample is thoroughly sieved, and placed in a plastic sample cup for XRF analysis. The
intensity of the sample response at the L-alpha energy region of lead is compared to known
lead reference standards for quantitation.
APPARATUS AND MATERIALS
1. Energy Dispersive X-Ray Fluorescence Spectrometer
A Kevex Model 7000 XES equipped with:
(a) MO source;
(b) LI-SI detector,
(c) sixteen (16) place rotating sample holder, and
(d) computerized data system for analyzing, comparing and storing sample spectra.
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2. 8 inch Floppy Data diskettes, IBM, or equivalent.
3. Sample cups, plastic, consisting of cup, o-ring, and cap, Spectra-Cup, Cat. No. 340,
Somar Labs. Inc., New York, or equivalent
4. Mylar film, 6 micron.
REAGENTS
1. U.S. Department of Commerce, National Bureau of Standards, Standard Reference
Materials
Unit Certified Lead
SRM Type Size Concentration
1579 Powdered Lead 35g 11.87%
Base Paint
1633a Coal Fly Ash 75g 72.4 ug/g
1645 River Sediment 70g 714 ug/g
1646 Estuarine Sediment 75g 28.2 ug/g
1648 Urban Paniculate 2g 0.655%
2. US EPA, Environmental Monitoring and Surveillance Laboratory (EMSL), Quality
Control Reference Standards
3. Instrument Calibration Standards
Dust M-10 2500 ppm 10 mg.
Dust M-50 2500 ppm 50 mg.
Dust H-10 25,000 ppm 10 mg.
Dust H-50 25,000 ppm 50 mg.
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SAMPLE COLLECTION AND TRANSFER OF CUSTODY TO THE U.S. EPA
Samples are collected in the field by Lead-Free-Kids staff, placed in labeled individual
envelopes, and submitted with chain-of-custody (COC) documentation to the U.S. EPA New
England Regional Laboratory (NERL) for XRF analysis. U.S. EPA personnel or their
contractors will acknowledge receipt of custody by signing and dating the COC document in
the presence of the LFK dust sample courier. The COC document is retained until sample
analysis has been completed and results have been entered onto it. Then the original COC is
returned to LFK with a cover letter.
1. Sample Preparation
a. Samples are assigned unique laboratory identification numbers, a sequential
five-digit number, which is subsequently recorded on the sample envelope,
chain-of-custody document, XRF Dust preparation worksheet, XRF analytical
result summary sheet, and on the cover of the sample analysis container.
b. Under the ventilation hood, the sample envelope is carefully opened at one end
(with scissors) and the dust is placed into a 60 mesh sieve.
c. The sieve is manually shaken for approximately 15 to 20 seconds.
d. All the fines are then transferred to the preweighed sample analysis container
using a glass powder funnel centered over and touching the center of the mylar
window of the sample container.
e. Information from the chain-of-custody, including weight of sample, and
laboratory ID number is recorded on the analytical results summary form.
f. All of the excess (non-filtered) soil/dust from the sample preparation is discarded
in a special barrel in the laboratory. In some cases filtered dust may be
removed for the analysis container if the quality of dust interferes with container
fabrication. However, all the dust must be weighed before excess dust is
removed.
g. The powder funnel and sieve are cleaned between samples to remove soil and
dust particles, using clean, compressed breathing air (grade D), or the like.
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h. The sampling cup is sequentially placed in the sample tray according to the
laboratory ID number for XRF analysis. Empty envelopes are retained and
returned to LFK staff along with sample results.
2. Sample Container Preparation
The sample containers consist of two small o-rings with tabs, two pieces of 6 micron
mylar film, a sample cup (which is slightly larger than the o-rings), and a container
cap.
a. Place a piece of 6 micron mylar film over one o-ring (tabs down).
b. Snap the sample cup into place on top of the o-ring.
c. Weigh sample cup parts excluding cap and round to 4 decimal places.
d. Place dust sample onto mylar film via glass powder funnel. Be sure that sample
is centered on film.
e. Place another piece of mylar onto sample cup over the dust and snap the second
o-ring onto the top of the cup (tabs up).
f. Reweigh sample container and round to 4 decimal places.
g. Snap container cap into place on top of cup.
Note: The container cap is only used for identification and handling of the sample.
All analyses must be performed with container cap removed.
h. Label the sample container cap with the correct sequential laboratory sample ID
number.
3. Standards Preparation
Study Control standards are prepared from previously analyzed and concentration
verified house dust samples. Standard concentrations should be prepared at
concentration levels and weigh ranges as presented below.
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Sample
Calibration
Weight
Std. Range
Dust M-10 2500 ppm 10 mg M-10 or 0.0 - 0.024g
DustM-50 2500 ppm 50 mg H-10
Dust H-10 25,000 ppm 10 mg M-10 or 0.025g or
greater
DustH-50 25,000 ppm 50 mg H10
4. Sample Preservation and Handling
No preservation is required. Handling of the sample, once it is placed in the analysis
cup, must be done in a gentle manner to keep the sample centered in the middle of
the mylar. This is especially important for samples requiring replicate analysis.
ANALYSIS PROCEDURE
The use of the Kevex 7000 XRF is relatively straightforward. The Kevex is normally left in
the standby mode (target .8, 30 kV, and 0.5 mA) between analyses to prevent x-ray tube
damage. House dust samples for lead are analyzed under the following instrumental
conditions: target .4, 30 kV, .5 mA. (Detailed instructions can be found in the User's Manual
for Kevex XRF Software.)
1. Instrument Set-Up
a. Turn the video monitor and plotter power on.
b. Insert the Master floppy disk into disk drive No. 0 (DYO).
c. Insert formatted floppy disk into disk drive No. 1 (DY1).
d. Boot the operating system by pressing the "Shift" and "Reset" keys
simultaneously. Next, press the "Q Vantx" and then the "Enter" key.
e. When prompted on the screen, enter the current date.
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f. After the current date has been entered, the spectral region of interest for lead
must be established. This is accomplished by pressing the blue double-headed
arrow (< >) key. The region of interest that should be obtained is from 7.04
Kilo-electron Volts (KeV) to 17.28 KeV, where the lead L-alpha (L-a) peak is
10.5 KeV and the lead L-beta (L-b) is 12.6 KeV. After the spectral region has
been established for lead analysis, wait for the asterisk (*) prompt and type in
ATO, PBSOIL4. Type in sample ID Numbers as 5 digit numbers followed by
-D- for each number at the end.
ex: Lab ID # 143 entered as 00143-D-
g. The first carousel run on the Kevex for the day must contain all four calibration
standards. Each additional carousel run must include one of the four study
control standard on a rotating basis. Calibration standards are run manually and
not on the ATO program.
2. Loading the Kevex Sampler (Carousel)
a. Push the "Reset" key (red) to shut-off the x-ray beam. (As a safety precaution,
the lid will not open when the x-ray beam is functioning).
b. Open the Kevex top and place sample cups into the sixteen (16) available slots
(numbered 0 through 15) on the circular carousel.
c. Set the Kevex XES to ATO (white key). Then proceed with the analysis.
3. Manual Analysis of Dust Samples
The analysis will be performed using the ATO and manual modes. The manual
method requires that the operator be presented while performing this type of analysis.
Keyboard commands required to initiate and perform XRF analyses are detailed
below:
a. Await (*); type "Clr", then press the "Enter" key.
b. Make sure white switch is on manual position.
c. Push yellow key next to sample number. Use numbered key pad on KEVEX to
enter desired position then hit enter.
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d. Push yellow key to target display and enter 4 using numbered key pad again.
e. Continue in this manner and enter 30 for KEY and .5 for mA.
f. On the screen keyboard hit the yellow ACQ button. When running the standards
you will manually stop them at their designated ppm concentration (2500 for
medium and 25,000 ppm for high) using the yellow stop key next to the acquire
key. Using the blue arrows (up and down) to increase and shrink the size of the
peak, let the sample run for between 20 and 30 seconds. Stop the peak when it
reaches the 2,5 mark designated by the numbered lines on the left side of the
viewing screen.
g. When you have stopped the peak at its desired height (2.5) type SMO to smooth
the curve. If the peak now falls below 2.5 it may be necessary to continue
acquiring the peak for a couple more seconds and again hit stop to halt peak.
Alternating between acquire, stop and smooth may be done an unlimited number
of times until the peak appears in the right position as long as the time count is
below 30 seconds. Time of analysis may not run over 30 seconds.
Note: Only calibration standards will be run on manual not dust samples.
h. Await (*); type "REA"d, press "Enter".
i. Await (*); type "SAV'e, press "Enter".
j. Prompt General Comments.
k. Response: Section is ignored, press "Enter".
1. Prompt: Enter Unit: (1) or (2).
m. Response: Type "1", press "Enter".
* n. Prompt: Enter Sample ID":
o. Response: type in Sample ID as assigned in XRF dust preparation worksheet
* Manual analysis does not automatically add a 4 onto die end of the identification
label and therefore the 4 is not needed for recall purposes.
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4. Automatic Analysis Procedure
a. At asterisk on screen type ATO.PBSOIL4 Enter.
b. Enter the last sample position but do not include standards that will run
manually.
c. Enter lab ID numbers for each corresponding position.
d. As the program runs you must be present to observe each lead sample peak as it
acquires for 30 seconds.
e. With screen parameters of <7.04 and 17.28> the compton scatter peak will be
the last peak visible on the right hand side. The lead peak will appear directly
above the blue arrow at the bottom of the screen.
f. If the lead peak rises faster then the compton peak it will be calibrated using the
high standard. If the lead sample peak does not rise above the compton peak,
the medium standard will be used.
g. To determine if the 10 standard or the 50 standard is to be used, identify the
weight of the sample. The sample is:
O.OOg - 0.024g use 10 standard
0.025g - O.lOOg or above use 50 standard.
5. Manual Quantitation and Comparison of Dust Samples
a. Await (*); type "RCL" (recall), press "Enter".
NOTE: The RCL (recall) command is used to recall a previously analyzed spectra
that has been stored on the floppy diskette (DY1). In this case, a previously
analyzed lead in dust calibration or reference standard for comparison to the
various dust samples analyzed and stored on the same diskette.
b. Prompt: Enter Unit: 1 or 2.
c. Response: Type "1", press "Enter".
d. Prompt: Enter ID:
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e. Response: Type the standard/label ID, press "Enter".
f. Prompt: Smooth Recalled Spectrum (Y/N)?
g. Response: Press "Enter".
h. Await (*); type "OVR" (overlay), press "Enter". The overlay command is used
to compare and normalize spectra from the disk. The normalization feature
(OVR) allows the operator to mark regions within the displayed spectrum as a
basis for normalization. This feature aids in the visual interpretation of data and
reduces channel-to-channel statistical fluctuations.
i. Prompt: Enter ID: add -D-4 to the end of each ID.
j. Response: Enter the sample ID, press "Enter".
k. Prompt Smooth Recalled Spectrum (Y/N)?
1. Response: Press "Enter".
m. Prompt: Mark Peak(s) or Region(s) Hit Enter When Ready a cursor will appear
on the screen.
n. Response: Mark the regions to be used for normalization by moving the cursor
with the left and right green arrow function keys. The peak to be painted is the
compton scatter peak. The screen parameters should be 9.60 - 19.84 use the
green" equal (=) key to paint the desired area.
Note: the paint cursor will move in the direction it was last set Press the "Enter"
key when finished.
o. The screen display will now include the standard spectrum overlaid by the
sample spectrum normalized to the same energy region of the spectrum. Direct
comparison of the lead (L-a) peaks can be made and a concentration (in ppm)
can be determined.
Note: The red peak is the standard peak which should read 2.5 (use the Blue up
and down arrows to set this). The white peak is the sample peak. Use the blue up
and down arrows to best compare the sample peak value ppm. Although the height
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of the red and white peaks will change the ppm value of the red (standard) will
always remain the same 2500 ppm or 25,000 ppm depending on the standard used.
p. The OVR sequence can be repeated for each sample on the disk (DY1).
6. A Modified Quantitation Procedure - This is basically the same procedure as
described above.
Dr. T. Spittler, USEPA Region I, Technical Services Branch Chief, Lexington,
Massachusetts initiated the use of a quick and easy method for the quantitative
analysis of lead in soil samples.
Dr. Spittler has determined that, when acquiring data for the 2000 ppm lead in soil
standard at an attenuation of 512 and the energy level for the compton's back
scattering energy peak at 15 KeV is at 50 percent intensity, each horizontal screen
division is equivalent to the response of ca. 800 ppm lead. To utilize this technique
for dust, follow the XRF instrument set-up guidelines as previously described in parts
1, 2, and 3 of this Section. To acquire, quantify, and store data, utilize the following
procedure:
a. Check sampler position at "0".
b. Await (*); press the yellow "ACQ" key.
c. Wait for energy level at 15.- KeV to reach 50 percent scale at a range of 512.
d. Press the yellow "Stop" key.
e. Await (*); type "SMO", press "Enter".
f. Await (*); type "REA", press "Enter".
g. Await (*); type "SAV", press "Enter".
h. Prompt: General Comments.
i. Response: Section is ignored, press "Enter".
j. Prompt: Enter Unit: (1) or (2).
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k. Response: Type "1", press "Enter".
1. Prompt: Enter Sample ID:
m. Response: type in sample ID as assigned in the XRF logbook.
n. Quantify the L(a) lead peak using the following scale:
Concentration Range of Lead
Attenuation (vertical scale division concentration)
64 0 to 700 (100 ppm)
128 0 to 1400 (200 ppm)
256 0 to 2800 (400 ppm)
512 0 to 5600 (800 ppm)
1024 0 to 11,200 (1600 ppm)
o. Await (*); type "CLR" (clear), press "Enter".
p. Advance the sample tray one space and repeat the analysis procedure.
QUALITY CONTROL
1. All quality control data should be maintained and available for easy reference or
inspection.
2. At the beginning of each operating shift all 4 study control standards are analyzed on
the first carousel. On following carousel runs analyze one standard (one per sixteen).
This is done to assess method accuracy and to correct for normal standard drift and
results should agree within + 20 percent of the true value.
3. At least one laboratory replicate should be analyzed for every 20 samples to verify
precision of the method. Replicate samples may be run at the end of an analytical
day in their own carousel.
4. At least one laboratory replicate should be analyzed at a frequency of 1 per 20
samples to verify precision of the method. Replicate samples maybe run at the end of
an operation shift.
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NOTE: True replicates of soil and dust samples are usually not possible since
chemicals such as lead are typically not uniformly distributed in these materials.
Additional handling of the sample may cause the dust to migrate away from the
center of the mylar. Care must be taken when handling samples. Care must be taken
in the interpretation of soil and dust replicate analytical results.
METHOD REFERENCE
1. Precision and accuracy data are not available at this time.
2. The performance characteristics for a dust sample free from interferences are:
Optimum Concentration Range: N/A ug/g
Detection Limit: NA ug/g
N/A: not available at this time.
VIL Boston Handwipe Sampling
Testing of hand lead will be conducted each time a blood sample is taken for lead analysis.
There will be a total of three hand lead determinations: the first baseline test will be done
before any abatement activities occur, and the second and third follow-up tests will occur 4-6
months and 9-12 after abatement activities are completed.
Since studies indicate that hand dust reaches equilibrium within two hours after washing, case
managers will make every effort to conduct the hand lead testing more than two hours after
the last hand washing reported by the parent or guardian.
Case managers will wear disposable gloves when obtaining a hand wipe. Lead in dust on
children's hands will be sampled by wiping each hand of the child with three separate
commercial wet-wipes. The Walgreen's brand wet-wipes will be used for the LFK study.
All surfaces of the hands, front and back up to the wrists will be wiped thoroughly with each
of the three wet-wipes. All six wet wipes will be placed inside the container provided by the
analytic laboratory. The container will be labeled with the child's name and LFK number.
Each case manager team will also prepare hand wipe blanks at regular intervals during the
sampling period (i.e. every tenth child). The hand wipe blank will be prepared by removing
six wipes from the wet-wipe container and handling them in such a manner as to simulate
wiping the child's hands. These wipes will be placed into a container labeled "BLANK",
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dated and submitted to the laboratory along with the regular samples. Blind external quality
control samples prepared by the EPA with dummy (seemingly correct) identifiers will also be
submitted to the lab.
Chain of custody forms will be initiated when hand wipe samples are taken. All samples will
be transported to Dennison Laboratories of Woburn, Massachusetts by the Lead Free Kids
Study driver.
The six wipes will be composited for chemical analysis. The method of extraction of the lead
from the wet wipes is currently being determined. The total quantity of lead found will be
reported as ug/pair of hands.
VIII. Boston Handwipe Analysis
Report of Analysis Method
1 M Nitric Acid Extraction
1. Place each sample in a labeled, acid-washed 800 ml beaker.
2. To each sample, add 100 ml of 1 M nitric acid prepared with deionized water.
3. Swirl each sample for 10 seconds.
4. Cover each sample with a watchglass and allow it to extract at room temperature for 2
hours.
5. Decant the acid solution from the handwipes into a labeled, acid-washed 250 ml beaker.
6. Add 50 ml of 1 M nitric acid to the handwipes in the 800 ml beaker.
7. Swirl the sample for 10 seconds.
8. Decant the acid solution into the same 250 ml beaker to composite the acid rinse.
9. Repeat steps 6,7, and 8 a second time for a total acid solution of about 200 ml
10. Cover the samples with a watchglass which is elevated above the beaker rim with glass
hooks. (The watchglass must be elevated to prevent "bumping" of the sample during
evaporation).
11. Place the samples on the hotplate at about 250°C.
12. Evaporate the samples to dryness.
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13. Add about 3-5 ml of 1 M nitric acid to each sample, rinsing the watchglass and the
sides of the beaker.
14. Heat the samples gently on a hotplate at 120-150°C to redissolve lead.
15. a. Filter the samples using Whatman, rinsing the beaker/filter paper/funnel with IM
HN03.
b. Evaporate to about 5 mL on a hotplate.
16. Transfer to an acid-washed 10 mL graduated volumetric flask, rinsing and diluting with
IMHNO3.
17. Shake sample well and transfer to borosilicate test tube and cover.
18. Measure lead concentrations using a Varian 1475 Atomic Absorption Spectrometer.
Report results in total ug/sample.
IX. Boston Lead Paint and Site Inspection
LFK participants' homes will be inspected to provide information on the extent of leaded
paint to deleading contractors and the project epidemiologist. The contractors will be given
this information so that they can make informed estimates on the cost of interior and exterior
deleading. The project epidemiologist will use the measurements for scientific purposes to
estimate the contribution of leaded paint to participant children's blood and hand lead levels.
The first part of this document describes how lead paint inspections will be conducted to
gather information for the deleading contractors. The second part describes how this and
additional information will be used for scientific purposes.
Lead Paint Inspection
Lead paint inspections will be performed according to current Massachusetts Department of
Public Health requirements by registered inspectors. The following forms will be used to
record the needed information on all properties:
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1. Adapted Massachusetts lead paint inspection forms
2. LFK interior deleading information form
3. LFK exterior deleading information form
Instructions for filling out these forms are as follows:
Make sure the address of each property is recorded on each page of each form and that
the participant child's room is designated on the appropriate form. Also record which
machine (PGT or Microlead) was used to measure the amount of leaded paint The
sides of the house will be labelled as follows: A - front, B - left, C - rear, and D - right
Window and doors in each room will be numbered from left to right Window
measurements should be taken from the header to the sill and from casing to casing. A
list of definitions and abbreviations that may be used on these forms is attached.
Lead Paint Measurements
Lead in paint will be measured using x-ray fluorescence (XRF). Two different brands of
XRF machines will be used to measure lead in paint for the deleading contractors: Princeton
Gamma-Tech (PGT) XK-3 and Microlead. The two different brands will be used because
they are the only machines that are available to the study and both are needed to conduct the
inspections in a timely fashion. Only PGT XK-3 measurements will be used for the scientific
study data since the two machines are not sufficiently comparable for research purposes.
Differences between the machines are as follows: The possible measurements oh the PGT
range from 0 to 10 mg/cm2 and those on the Microlead range from 0 to approximately SO
mg/cm2. In general, the Microlead XRF reads leaded paint many more inches below the
surface than the PGT does. When we tested the comparability of the two machines, we
observed that repeated Microlead readings of the LFK conference room windowsill were 2.5,
2.2, 2.2 and 2.9 and repeated PGT readings of the same spot were 0.2,0.7,1.4, and 0.6.
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(Note: the first two readings were taken on one day and the second two readings were taken
two days later).
XRF Machine Calibration
Both machines will be calibrated twice a day: once in the morning and again in the
early afternoon. An XRF calibration form will be filled out each time a machine is
calibrated (see attached). Calibration will involve making two sets of ten readings. The
first set of ten readings will be done using a zero standard and the other set will be
done using known lead standards of various levels (i.e. 1.45, 3.5 mg/cm2).
XRF Machine Use in the Field
XRF readings of lead paint concentrations are read directly from the digital read-out on
the machine. If the reading is 2.0 mg/cm2 or less, three readings will be taken and the
average will be recorded on the lead paint inspection form. If the inspector believes
that there is lead present on a surface despite a negative or very low XRF reading,
sodium sulfide will be used to test for leaded paint. The results of both the XRF
measurement and the sodium sulfide test will be recorded on the inspection form.
XRF measurements will be taken on painted and on (non-vinyl) wallpapered surfaces.
The determination of what constitutes an appropriate surface will be made by the
inspector. Measurements will be taken on the interior and exterior of the participant's
dwelling. The interior is defined as the apartment or living quarters of the LFK
participant The exterior is defined as the common hallways, stairs, entrances, porches,
accessible basements as well as the exterior walls of the building. The exterior may
also include any other buildings (i.e. garages) and fences on the property. Interior
measurements will be taken on walls and woodwork including baseboards, windowsill,
etc. in each room of the participant's unit Ceiling measurements will be taken only if
the paint on the ceiling is peeling.
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Additional Deleading Information and Instructions
Besides taking the lead paint readings, the inspectors will record other pertinent
information/instructions for the deleading contractors. Examples of such instructions are:
1. In general, baseboards will be made intact and capped with quarter round moldings.
When lead painted decorative moldings are present, record the width that will be
needed for replacement
2. When porch rails or other items require replacement, specify materials and
workmanship common to the area. Also note that this will require further
negotiation with the landlord.
3. Indicate whether the door and window trim are decorative or flat. Flat boards will
be replaced with #2 pine. Decorative moldings will be dipped off-site.
4. Ceilings will be tested for lead only if they are peeling. If peeling ceilings are not
accessible, note that they should be made intact on the comment sheet.
5. Lead painted basement windows wherever possible will be covered with plexiglass.
6. Measure rails and count ballisters on exterior porches.
7. Exterior window sills and wells will be covered with aluminum and caulked.
Lead Paint Measurements for Scientific Purposes
Since the Microlead and PGT XRF machines are not sufficiently comparable, only the PGT
measurements taken by the lead paint inspectors will be used for the project's scientific data.
Thus, only about 50% of the properties initially inspected will have measurements useful to
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test the study hypothesis. Once the lead paint inspectors finish gathering all the data needed
for deleading, they will return to the properties where the Microlead was used to take the
measurements and will re-take six measurements using the PGT XK-3.
The six measurements will re-taken in each of the following rooms since it is likely that the
participant child spends most of his/her time there: the child's bedroom, the kitchen, and the
living room. One measurement will be taken on the lower pan of the wall and one on the
window sill (i.e. woodwork) in each of these rooms. The calibration and measurement
procedures described previously will also be followed during this round of measurements.
Special study data collection forms will be developed for recording these data. These same
data will be abstracted from the inspection forms for the properties that were originally tested
using the PGT.
Abbreviations and Definitions for Lead Paint Inspections
n/a = not accessible
cov = covered
rep = replace
y = yes
n = no
dip = off-site removal of lead from surface by an approved method
R&R = remove and replace (unless otherwise noted, the replacement material will be #2 pine)
neg = negative
pos = positive
upper walls = walls above five feet
lower walls = walls below five feet
mil = make intact
porch = the area extending from the house, the wall the porch is attached to is the exterior of
the house.
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scrape = delead on-site
interior = the apartment or living quarters of only the LFK participant, excludes common
areas within the building.
exterior = the common hallways, stairs, entrances and porches as well as the exterior walls of
the building, and all other buildings and fences located on the property.
All other abbreviations are described on the individual forms.
X. Boston Water Sampling
We wish to obtain a tap water sample that will be predictive of the child's blood lead level.
Since a standing water sample (i.e. water that has been standing in the pipes for at least 8
hours) is thought to be most predictive, it will be necessary for the parent or guardian to take
the water sample. The case managers should give the following instructions to this
individual:
The tap water sample should be taken from the cold water faucet of the kitchen. It
should be a first flush sample of water that has been standing in the pipes from 8 to 18
hours. We foresee two main options for the time a sample is taken: (1) it can be taken
first thing in the morning, or (2) if all of the residents of the household have been out
of the house for the entire day it can be taken at the end of the day (Le. dinner time).
We will provide a labelled plastic bottle for the sample. The bottle should be
completely filled with the water. The bottle contains a small amount of acid
preservative and so you should store it unopened in a safe place until you take the
sample. We will return to pick up the sample at a convenient time.
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Before dropping off a water collection bottle case managers will fill out and affix the label
provided by the laboratory. The chain of custody form will be initiated when case managers
pick up the water sample. The water samples will be shipped to the Hall-Kimbrell laboratory
in Lawrence, Kansas by U.S. Postal Service.
XI. Boston Water Analysis
A. Reference
Method 239.2 (Atomic Absorption, furnace technique) EPA - 600/4-79-020
Optimum Concentration Range: 5-100 pg/L
Detection Limit: 1 pg/L
B. Application
Tests for lead arc carried out using the graphite furnace atomic absorption technique as
described herein. Samples, blanks, quality control, replicate, and spike test solutions are
prepared as described and placed in trays for automatic sampling. This instrument setup
and analysis steps are performed using the parameters defined.
C. Preparation of Standard Solution
1. Stock lead solution: Commercially available containing 1000 mg/L (1000 ppm)
of lead.
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2. Matrix modifier - ammonium monobasic phosphate + magnesium nitrate solution:
Transfer 4 grams of NH^HjPC^ monobasic Ultrex reagent and 0.2 grams of Mg
(NO3)2, Suparapure, to a 100-mL volumetric flask and makeup to mark with
deionized distilled water (DW) containing 0.5% (v.v) HNO3.
3. Working lead solution: Dilute the stock solution to the ratios needed as
calibration standards at the time of analysis. The calibration standards and
reagent blank must be prepared with the same acid, i.e., 0.5% (v/v) HNO3. The
reagent blank used in all subsequent dilutions is prepared by diluting 5 mL cone.
HNO3 to 1 L with DW. A 1-ppm solution is prepared by dilution of the 1000-
ppm stock solution with reagent blank. This 1-ppm solution is used to obtain
calibration standards of 0, 5, 10, 25, 50, and 100 ppb lead To obtain the
calibration standards, withdraw appropriate aliquots of the 1 ppm solution and
dilute to 100 mL with reagent blank.
D. Sample Preparation
All samples solutions for analysis are acidified in the field and contain 0.5% (v/v)
cone. HNO3.
E. Instrument Parameters for Lead Analysis
1. Drying Time and Temp: 40 sec. - 120 °C
2. Charring Time and Temp: 40 sec. - 1000 °C
3. Atomizing Time and Temp: 5 sec. - 1800 °C
4. Cleaning Time and Temp: 5 sec. - 2600 °C
5. Cooling Time and Temp: 20 sec. - 25 °C
6. Purge Gas Atmosphere: Argon
7. Wavelength: 283.3 nm
8. Slit: 0.7 nm
9. Tub/site: Pyro coated tube with L'vov platform
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10. Matrix Modifier Setting: 5 pL
11. Sample and Standard
Quality Setting: 20 uL
12. Max power: 30
13. Background correction mode: On
14. Lamp: Electrodeless discharge lamp (EDL)
Note: Parameters 1, 2, 4, and 5 use 1 second ramp time. Parameter 3 uses 0 second
ramp time and gas stop flow.
F. INSTRUMENT USED
Perkin-Elmer Zeeman model 5100 atomic absorption spectrophotometer equipped with
a model AS-60 autosampler and an HGA model 600 graphite analyzer.
G. LABORATORY USED
Hall-Kimbrell Laboratory, Kansas City, Kansas
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Appendix A-3: Cincinnati Protocols for Sampling and Analysis
I. Cincinnati Soil Sample Collection
The Primary method of determining the lead content of the soil will be by XRF (Kevex
Analyst 770). Validity of results will be confirmed by re-analysis of 1/50 or 2% of the
samples by atomic absorption spectrometry. It is expected that the same limit of detection
and coefficient of variation will be obtained with either technique.
A. Site Description
Aerial photographs with ground verification will be used to delineate the potential abatement
areas and the soil sites within the abatement areas.
Aerial photographs will be used in place of a drawing to outline the soil area to be sampled
and the samples taken. The photo will show the relationship of the soil area to buildings,
fences, and play equipment or areas (if present), and most bare areas which will be verified
by ground inspection.
A Mylar film overlay will be used on the aerial photo of the soil area and used to mark any
subdivisions of the area, the sample patterns chosen, and other notations as appropriate.
Field sketches and measurements will be used to supplement the aerial photos as necessary,
particularly in the case of small area samples.
B. Preliminary Determinations and Preassignment of Sample Patterns
In order to bring together different types of information about a soil site, such as owner's
name,location of the soil, consent of the owner to sample, and level of lead found in the soil,
it was determined that the system of book, page, and parcel used by the Hamilton County
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Auditor to determine value and ownership of land for taxation purposes, provided a working
system for uniquely identifying a unit of land. In addition, because parcels of urban land are
generally of regular and consistent size and shape, and large areas of soil are made up of
adjacent parcels, the parcel could serve to delineate the boundaries of a soil area or subarea.
Therefore, the parcel boundaries serve as the basis for subdividing a large soil area into
subareas.
Because this is a pre-existing system, the decisions regarding appropriate sub-area
designations and sample pattern determinations have been simplified and made more rigorous.
Sample lines are used exclusively within parcels which contain soil of appropriate size to
require a line. A line segment from which sample cores are composited will not exceed 40
feet. Line segments which make up a continuous line will be labeled 1.1, 1.2, 1.3, etc. The
number of line samples within a parcel varies. Adjacent line segments within a parcel will be
labeled 1.1, 2.1, 3.1, etc. Soil in a parcel which is adjacent to a potential source of higher
lead contamination, such as a building, will receive more intense sampling than soil which is
relatively isolated from potential additional sources of lead. The source pattern is believed to
be the most appropriate to us in an urban area, where most soil is near building foundations
or streets, or was previously built upon.
Soil areas which are too small to support a line pattern are randomly sampled, following the
guidelines for the small area pattern.
Targeted samples are also taken in appropriate areas such as bare areas or near play
equipment. Since the targeted sample is intended to reflect potential higher exposure of
children to lead in soil, only composited surface scrapings of the soil are taken.
The location and sample log number of samples to be obtained within a soil area will be
preassigned, based on field observations of the area and the parcel boundaries. The field
observations and sample determinations are made by senior staff. A worksheet accompanies
the sample collection and is used to record sample I.D. numbers and the location of samples.
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After the field observations are completed, the preliminary observations worksheet, field
sketches, and sample worksheets are all stored in a notebook which contains all information
about a soil site. From the field sample worksheets, the appropriate sample bags are labeled
and kept with the site notebook prior to sample collection.
C. Coding of Samples
Each potential abatement area is assigned a four- letter abbreviation which is called the
"Neighborhood ID".
Each soil site within the abatement area is arbitrarily assigned a number from 001 to 999. A
site may be made up of multiple parcels, or may be a fraction of a parcel.
The combination of neighborhood I.D. and soil site quickly identifies the area of interest, and
is an aid to the sampling crew.
Each sample is assigned a unique sequential sample number. The record of sample numbers
is kept in a bound notebook labeled "Soil Sample Number Log Book". With the sample
number, the Neighborhood I.D., soil site number, and book, page, and parcel of the assigned
number is also recorded. The Soil Sample Number Log Book also serves as a record of
sample numbers which are preassigned to control samples, such as lab preparation blanks and
blind samples.
D. Collection of Soil Cores
The collection of soil cores is done by a trained team of field samplers. Some of the team
members may have also conducted the preliminary field observations. The soil site
assignment photos, sample bags and worksheets are contained in a carrier bag with other
supplies and a modified soil corer. A soil corer with a hammer attachment will be used if
needed.
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Upon arrival at the site to be sampled, both team members measure and mark with flags the
parcel to be sampled. One team member will use the soil corer and the other will help bag
the 2 cm cores, check the worksheets and make notes. Team members will be trained in both
aspects of sample collection and may change roles.
The corer is driven straight into the ground (using the hammer attachment if needed) at the
location of the first core. An appropriate depth of about 17 cm is reached at the "STOP" line
on the corer. Rock the corer slightly to loosen it, then pull it straight out of the ground,
being careful to not dislodge the top 2 cm.
Push the core to the top edge of the cut-out of the corer.
Measure the top 2 cm and bottom (13-15 cm) from the lines marked on the cut-out portion of
the corer. Cut these sections with the stainless steel spatula and transfer each into the
appropriately labeled color-coded bag. The "top" bag is RED, the "bottom" bag is BLUE.
The central section of the soil core may be discarded.
Before or after the 2 cm sections have been bagged, one team member will take a "surface
scraping" adjacent to the location of the core sample. Using the stainless steel spatula, scrape
the surface of the soil in at least 5 places, attempting to scrape no deeper than 0.5-1.0 cm.
Composite the scrapes in a WHITE bag, attempting to get approximately the same volume of
soil as the composited cores.
When sampling for an area is complete, the soil samples and paper work are stapled together
for transport to the field office/lab.
E. Soil Sample Preparation
Soil sample preparation is that set of procedures used to process soil samples, which results in
a soil sample ready for lead-concentration analysis by means of the Kevex-XRF instrument.
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These procedures include drying to constant weight, sieving, and final packaging of samples
for shipment to the laboratory.
1. Transfer of Custody
Soil samples collected in the Cincinnati Soil Project study areas are returned to
the Main Street field office where custody of the samples is transferred
immediately from the environmental monitors to an individual designated by the
Associate Project Manager for Technical Matters. At the time of this transfer, the
designated person checks each sample collection worksheet for completeness,
legibility, and accuracy. The bags containing the samples are inspected for label
completeness and accuracy, and the identifiers on the sample bags are checked
against the identifiers on the sample collection worksheet Any discrepancies in
this information are addressed at this time.
The sample numbers on the bags are then compared with the sample numbers in
the soil sample log book. The area, book, page, and parcel numbers in the log
book are compared with the book, page, and parcel numbers on the sample bags.
The day's date is written next to the sample number in the log book and initialed,
signifying that all information is correct, complete, and in custody. The samples
will remain in custody at the field office until they are transferred to other labs
for analysis. After the individual sample bags have been checked, they are then
returned to the larger bags in which they were stored during the collection
process. The larger bags are then placed in plastic storage bins for storage. The
samples are stored either in a designated storage area or the soil preparation lab.
2. Air Drying of Samples
A bag of samples is removed from a storage bin and unpacked After the sample
bags are removed from the outer plastic bag and placed on the lab bench, the
sample number and the book, page, and parcel information, are written on the
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bottom of a six inch, plastic-coated paper plate and the sample number is written
on the outer edge of the top of the plate. The sample bag is opened and the
contents are dumped onto the previously marked plate. The soil is spread evenly
over the surface of the plate with a stainless steel spoon or spatula. The sample
bag is stapled to the plate. The drying plates, containing the soil samples, are
placed on a tray for drying and when a tray is filled with plates it is placed on
the drying shelf. Prior to placing the tray on the drying shelf, a label identifying
the date on which the sample was placed on the tray is attached to the end of the
tray so that it is visible from the front of the drying shelves.
3. Sample Sieving
Each sample is sieved twice; once with a number 10 sieve with a mesh size of 2
millimeters, followed by a number 60 sieve with a mesh size of 250 microns.
All sieving takes place under a hood with the exhaust fan operating and the sash
at the designated position. The appropriate sash position is approximately at the
half-open position. The proper position of the sash is marked on the side of the
hood and is approximately eleven inches above the counter top. With the sash in
this position an adequate movement of air at the hood opening will reduce the
probability of exposure to lead dust for lab personnel.
The first step in the sieving process is to label the sample jars. The sample jars
should be labeled in pairs. Two jars should be labeled with the sample number
recorded on the plate of the sample to be sieved. That number should be
followed by "T" on one jar and "U" on the other jar. The same number should
be written two times on each jar on opposite sides of the jar.
In order to sieve the soil sample, the 2mm sieve should be placed on top of the
sieve pan. Dump the sample from the plate into the sieve and work the sample
through the sieve until no more material passes through the screen. The material
remaining in the sieve, consisting of rocks, glass, cigarette butts, paper and grass
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should be discarded into a box lined with a plastic garbage bag which is inside
the hood. Discarding the material outside of the hood has the potential for
contaminating both personnel and the lab. After the material in the sieve has
been discarded, the sieve should be tapped several times on a hard surface and
brushed out with a paint brush used for that purpose. The outside and the inside
of the sieve should be brushed in order to prevent potential contamination of
subsequent samples.
Stir the sample to homogenize the contents and transfer about one third of the
material from the sieve pan to the jar labeled with the proper sample number
followed by the letter "T", to indicate a "total" fraction. This should be capped
and set aside.
The number 60 sieve is placed on the top of another empty, clean sieve pan. The
material is transferred from the first sieve pan to the number 60 sieve and the pan
is brushed so that any remaining material in the pan is transferred to the sieve. A
stainless steel spoon is used to move the material around the 250 micron sieve
until no more sample will pass through the sieve. Any sand or other material
remaining in the sieve is then discarded into the lined box within the hood. The
material in the sieve pan is then transferred to the sample jar labeled with the
proper number followed by the letter "U". This part of the sample is considered
to be the "urban" fraction of the soil.
The sieves and the pans should be brushed out with the paint brush provided for
that purpose. This step is necessary in order to prevent contamination of
subsequent samples. Save the drying plate after checking against the numbers on
the sample jars to insure that they correspond to the numbers on the plate. Plates
may be discarded after all samples are analyzed.
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II. Cincinnati Soil Analysis
A. XRF Analysis
Approximately 2 g of loose sieved soil, less than 250 microns in particle size,
will be weighed and placed in labeled sample cups (Chemplex Industries, Inc.,
Cat. No. 1530), fitted with windows of 1/4 mil thick X-ray polypropylene film
(Chemplex Industries, Inc., Cat. No. 425).
The instrument configuration for the Kevex Delta Analyst Energy Dispersive X--
ray Spectrometer is as follows:
1. Kevex Analyst 770 Excitation/Detection Subsystem:
a. X-ray tube: Kevex high output rhodium anode
b. Power supply: Kevex 60 kV, 3.3 mA
c. Detector/cryostat: Kevex Quantum - UTW lithium, drifted silicon. 165 eV
FWHM resolution at 5.9 KeV.
2. Kevex Delta Analyzer
a. Computer mainframe: Digital Equipment Corp, PDF 11/73
b. Computer software: Kevex XRF Toolbox n, Version 4.14
c. Disk drives: Iomega Bernoulli box, dual drives, 20 MB
d. Pulse processor. Kevex 4460
e. Energy to digital converter: Kevex 5230
3. Operating Conditions
a. Excitation mode: Mo secondary target with 4 mil thick Mo filter
b. Excitation conditions: 30 kV, 0.5 mA
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c. Acquisition time: 100 livetime seconds
d. Shaping time constant: 7.5 microseconds
e. Sample chamber atmosphere: air
f. Detector collimator: Ta
4. Analytical Conditions
a. Escape peaks, but not background should be removed from all spectra
b. The intensity ratio, defined as the integral of counts in the Pb (LA) window
divided by the integral of the counts in the Mo (KA) Compton scatter
window, should be determined for each spectrum.
c. The intensity ratios for the standards should be used to determine a linear
least squares calibration curve.
5. Calibration Standards
The following Cincinnati soil standards will be used to produce a calibration ^^
curve. These standards consist of mixed soil or surface scrapings from many
areas in Cincinnati. The lead content reported here is the average of a triplicate
determination. These standards were analyzed by a nitric/perchloric acid
digestion, followed by atomic absorption.
ppm Pb
15.0
121
619
704
2030
4576
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6. Calibration Check
The 619 and 2030 ppm standards will be used as calibration checks.
B. Acid Digestion for Analysis by Atomic Absorption
Weigh an aliquot of 1 g sieved soil into a tared, acid-washed 100 ml beaker.
Add 50 ml 7N HNO3, cover and digest gently at 95 ° C for 2 hours, stirring
occasionally. If excessive foaming occurs, remove from the heat periodically until
foaming subsides. Maintain at least 25 ml in the beaker by adding 7 N HNO3 as
necessary.
Cool and dilute with 10 ml IN HNO3. Filter through a glass funnel with Whatman
No. 54 filter paper into a 100 ml class-A volumetric flask. Rinse filter and labware
with IN HNO3, and dilute to volume.
Shake the volumetric flask well and pour about 10 ml of the acid extract into a clean,
labeled polystyrene test tube with screw cap. This portion of the sample will be
delivered to the Analytical Laboratory for AAS analysis.
An additional portion of about 10 ml of the acid extract should be placed in a second
clean, labeled polystyrene test tube and retained until AAS analysis is complete.
Dispose of the remainder of the sample extract
All unknown samples are first screened by aspirating a sample and determining the
range of sample concentrations at maximum scale expansion. Samples are then diluted
with 1.0 M nitric acid to bring the sample concentration within the linear range of the
instrument After samples are analyzed the lead concentration is calculated and the
results reported in ppm.
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When results have been received on a set of samples, the Director of the Hematology
and Environmental Laboratories will handle disposal of the acid extracts.
in. Cincinnati Surface Dust Collection
A. Vacuum Method
1. Collection Apparatus for Vacuum Method
The apparatus to be used to collect surface dust is a personal air monitoring pump, an
air monitoring cassette containing a 37 mm diameter 0.8 micron polycellulose acetate
filter, and a collection attachment.
Interior dust is sampled from areas such as the floor adjacent to the entry; from
carpeted or bare floors; from window sills and window wells.
A weight of dust is collected over a measured area, or composite of measured areas so
that three measures are obtained:
Dust Loading = mg dust/m2
Lead Loading = pg lead/m2
Lead Concentration = pg lead/g dust or PPM lead.
To obtain a sample:
Assemble the apparatus shown: connect the collection apparatus to the cassette and
the cassette to the pump. Delineate the area to be sampled A plastic template is used
to delineate some areas to be sampled, such as carpets. The interior dimensions of the
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template are 25 cm x 25 cm. Alternatively, the actual area covered is measured in
centimeters.
Turn on the pump. Hold the collection apparatus at a 45 degree angle to the surface.
Draw the attachment over the surface to be sampled in one direction until the area is
covered. Check the attachment to be sure it is not blocked. Repeat the vacuuming of
the area twice more for a total of three passes over the area in the same fashion so
that the area is completely covered.
Turn off the pump. Disconnect the cassette from the pump and plug the outlets.
Record the appropriate information on the worksheet.
B. Sample Areas
Entry (E): A floor area inside the residence directly adjacent to the main entry to the
residence.
Floor (F): A composite sample of at least 3 floor areas which should include but is not
limited to a sample from a high-traffic area in the main living area and a sample from the
child's bedroom.
If carpet is present in the residence it shall be the first choice of sample area. If carpet is not
present, a mixture of non-carpet floor areas will be sampled.
Window (W): A composite sample of at least three window areas (windowsills and window
wells), including but not limited to a window in the main living area and a window in the
child's bedroom. ?
Mat (M): Floormats sampled will be those which are placed in the entry area of the residence
by study personnel at the appropriate time the floormat will be placed in a plastic bag which
will be sealed for transport into the residence. The floormat will be sampled when it is put in
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place in the home and will be sampled again after the year's abatement activities are
completed. At this time it will be replaced and sampled at each environmental visit occurring
over the next year.
C. Sketch of Residence
In order to more fully describe where samples have been collected, a floor plan of the
residence will be made by the sampling crew (Figure 4). This sketch should show the
primary features of the residence such as window placement, door placement, the direction of
the residence to the nearest street, and the relationship of the various rooms to each other.
Rooms should be labeled according to their apparent function. The placement of the sample
areas should be noted.
This sketch will be an important aid in returning to the sample areas to collect dust samples
in the same locations after abatement is completed and during the post abatement
recontamination monitoring.
B. Dustfall Collection
Dustfall samples are collected in polypropylene containers which have snap on lids. The
containers have the dimensions 10 1/8 in. x 9 3/4 in. x 2 1/2 in. deep. They are
"Tupperware"-type containers.
The dustfall containers are clean and sealed and not opened until placed in the residence at
the time of preabatement visits in 1989 and 1990. In practice, it is best to place the container
above floor level in a relatively inconspicuous spot so that no one will interfere with it The
first choice for placing the container will be on top of the refrigerator in the kitchen. If this
is objected to by the family, a nearby location may be found. Only the container is placed in
the home. The lid, appropriately labeled, is retained by the sampling crew until the sample is
retrieved after completion of abatement activities for that year.
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IV. Cincinnati Surface Dust Analysis
A. Preparation of Surface Dust Samples for Acid Digestion
1. All the glassware to be used in this preparation must be acid washed. After
washing with lab detergent and tap water, the glassware is soaked for a minimum
of 4 hours in 20% v/v nitric acid/deionized water. Glassware must be oven-dried
prior to use.
2. The dust samples are contained in plastic air sampling cassettes.
3. Obtain enough acid washed 100 ml beakers to prepare a set of samples. Enough
beakers to prepare about 25 samples is usually appropriate. Label the beakers
with the correct sample numbers. Handle the beakers with laboratory tongs or a
paper strip.
4. After the beakers have oven-dried and are cooled to room temperature obtain the
tare weights of the beakers using a calibrated 4-place analytical balance.
5. Quantitatively transfer the dust sample to the beaker. Using a spatula, carefully
pry the top section off the cassette. Dump any loose dust into the beaker. Rinse
the interior surface of the cassette thoroughly with distilled deionized water and
add the rinsings to the beaker. Take apart and rinse each section of the cassette.
However, do not remove the two end caps. Remove the filter by handling it with
tweezers and rinse it also, adding the rinsings to the beaker. Rinse the support
pad in the same way. The used cassette, filter, and support pad may be
discarded.
6. An empty cassette will be used as a laboratory blank. It will be treated exactly as
if it were a sample.
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7. Cover each sample with a watch glass supported by two glass hooks. Evaporate
the dust rinsings under a hood on a hot plate at about 200 ° C to near dryness.
Do not allow sample to blacken.
8. Transfer the dust beakers to a drying oven which has a maximum temperature of
105 ° C. Dry in the oven overnight. (Overnight drying of the sample will
achieve constant weight Since a full day's work is needed prior to this step,
overnight drying becomes the standard procedure.)
B. Acid Digestion of Surface Dust Samples. (Hot Nitric Acid Digestion)
1. The reagents used will be 7 M and 1 M reagent nitric acid prepared with distilled
deionized water.
2. To each sample, add 25 ml of 7 M nitric acid from a repeater dispenser. Use the
acid stream to wash down the sides of the beaker well.
3. Place the samples, covered with a watchglass, in a hood on a hotplate at 120 ° C
for two hours.
4. Cool the sample in the hood.
5. Filter the samples through Whatman #54 paper in glass funnels over 50 ml
volumetric flasks. The entire filtration procedure should take place under a hood.
Rinse the beaker and filter paper with 1 M nitric acid to effect a quantitative
transfer and filtering using standard laboratory procedures.
6. Make the sample up to volume with 1 M nitric acid.
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7. Stopper the 50 ml volumetric and shake well. Pour two aliquots of about 10 ml
each into new labeled polystyrene test tubes. One of these aliquots will be used
for AAS determination. It is important to keep the other tube in the event of
leakage or breakage of the first tube. Cost prohibits sample storage or in the 50
ml volumetric.
8. The samples are then submitted to the AAS lab for determination of lead.
9. Funnels and volumetrics will be rinsed between sample runs with distilled
deionized water (3 times) and then with 1 M nitric acid (1 time).
V. Cincinnati Dustfall Analysis
A. Preparation of Dustfall Samples for Acid Digestion
1. Dustfall samples are contained in plastic containers with lids.
2. Using clean forceps remove any obvious foreign object from the dustfall container
such as insect bodies,leaves, pins, etc., and discard.
3. Using a glass wash bottle filled hot distilled/deionized water and a rubber scrubber,
quantitatively transfer the dustfall samples by rinsing to a labeled, acid-washed
250 ml beaker. Rinse the inside lid of the dustfall container also. If the dustfall
container is very heavily loaded, an additional labeled 250 ml beaker may be
used.
4. Cover each sample with a watchglass supported by two glass hooks. Evaporate the
dustfall rinsings to about 50 ml on a hot plate at about 200 ° C. If more than one
beaker was used, amalgamate the rinsings.
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5. Rinse the concentrated dustfall rinsings with hot distilled/deionized water and
scrape into a tared acid-washed 100 ml beaker. Beaker tare weights will be taken
on a calibrated 4-place analytical balance.
6. Cover and evaporate the remaining water in the dustfall sample under a hood on a
hot plate at about 200 ° C to near dryness. Do not allow samples to blacken.
7. Transfer the covered sample beakers to a drying oven which has a maximum
temperature of 105 ° C. Dry in the oven overnight.
8. Keep the samples covered. Place the samples in a desiccated cabinet to cool prior
to weighing.
9. Obtain the gross weight of the dustfall sample plus beaker. Subtract the tare
weight of the beaker from the gross weight of the sample plus beaker to obtain
the total sample weight collected.
10. At this point, the samples should be covered with parafilm for storage prior to acid
digestion.
B. Acid Digestion of Dustfall Samples (Hot Nitric Acid Digestion)
1. The reagents that will be used consist of a 7 M and a 1 M reagent nitric acid
solution prepared with distilled deionized water.
2. To each sample, add 25 ml of 7 M nitric acid from a repeater dispenser. Use the
acid stream to wash down the sides of the beaker well.
3. Place the samples covered with a watchglass in a hood on a hotplate at 120 ° C for
two hours.
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4. Cool the sample in the hood.
5. Filter the samples through Whatman #54 paper in glass funnels over 50 ml
volumetric flasks. The entire filtration procedure should take place under a hood.
Rinse the beaker and filter paper with 1 M nitric acid to effect a quantitative
transfer and filtering using standard laboratory procedures.
6. Make the sample up to volume with 1 M nitric acid.
7. Stopper the 50 ml volumetric and shake well. Pour two aliquots of about 10 ml
each into new labeled polystyrene test tubes. One of these aliquots will be used
for AAS determination. It is important to keep the other tube in the event of
leakage or breakage. Cost prohibits sample storage in the 50 ml volumetric
flasks. Therefore, the remainder of the sample in the volumetric is discarded.
8. The samples are then submitted to the AAS lab for determination of lead.
9. Funnels and volumetrics will be rinsed between sample runs with distilled
deionized water (3 times) and with 1 M nitric acid (1 time).
VI. Cincinnati Exterior Dust Sample Collection
A. Collection Apparatus
The equipment needed to collect exterior dust samples consists of:
1. Stiff-bristled brush and paint brushes
2. Ziploc-type plastic sample bags
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3. UltravacTM vacuum with various attachments. This vacuum is manufactured by
the Top 10 Merchandise Co. of Sherman Oaks, CA. The BON-AIRE vacuum
manufactured by Bon-Aire Industries, Inc., of Long Beach, CA. is also used
and found to have similar air flow characteristics.
4. Template with interior dimensions of 6 inches by 2 feet
5. Dust sampler's trowel
6. Carpenter's chalk
B. Power Supply for Vacuum Operation
A portable battery supply is used for field operation of the Ultravac. This consists of three,
twelve volt rechargeable lead acid batteries which are wired in parallel. The batteries are
carried in a plastic case for portability.
C. To Obtain a Sample from a Single Template Area:
1. Within the specified area to be sampled, choose an area with a visible
accumulation of exterior dust.
2. Place the template on the area to be sampled. Using carpenter's chalk draw a line
around it and remove.
3. Within the template area, loosen the surface dust/din with the stiff-bristled brush
and transfer as much dust as possible to the sample bag, using a paint brush
and the plastic trowel. Transfer to sample bag.
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4. Turn on the vacuum. Holding the appropriate nozzle at about a 45 degree angle to
the surface, sweep the surface in one direction until the template area is
completely covered. Sweep once around the inside edge of the drawn template.
Repeat this 2 more times alternating directions at 90 degree angles.
5. Raise the nozzle and tubing to its full height and tap the tubing to shake any loose
dust from the nozzle or tubing into the vacuum.
6. Turn off the vacuum.
7. Go on to the next area to be sampled.
D. Transfer of Composited Exterior Dust Samples
1. When all template areas that will make up a single composite sample have been
sampled, repeatedly tap the tubing from top to bottom three times and then turn
off the vacuum.
2. Empty the contents of the cassette into a sample bag.
3. Remove the top section of the vacuum. Brush any dust into the bowl of the
vacuum.
4. Now open the cassette and brush the contents into the bowl of the vacuum.
5. Tap the exterior dust to one side of the bowl of the vacuum and pour it into the
sample bag. Brush any remaining dust from the bowl into the sample bag.
6. Seal the ziploc bag securely.
7. Go on to the next composite sampling site.
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E. Sampling Sites for Exterior Dust
Three exterior dust sampling strategies will be used.
1. Neighborhood-wide sampling of abatement area
Composite samples will be taken along designated blocks which will not exceed
500 feet A template area will be sampled no less than every 100 feet along this
length. For smaller areas, no less than four template areas will make up the
composite.
Two areas will be sampled which will be defined as follows:
a. Street gutter: the interface of the street surface and the curb.
b. Sidewalk: the edge of the sidewalk farthest from the street; or
alternately, when a building abuts the sidewalk, the interface of the
sidewalk surface and the building.
Since streets and sidewalks are not assigned parcel numbers on the Hamilton
County Auditor's plat maps, an extension of the book, page and parcel system
will be used to assign a numerical identifier to the streets, sidewalks, and alleys
to be sampled. The basic unit which will be assigned a "parcel" number will be
the length of one side of a city block (up to 500 ft) along a major street,
between the sidewalk and the center of the street Within this area the two
composite samples from street gutter and sidewalk will be taken as described
previously.
Alleys will also be sampled. For sampling and "parcel" designation purposes, the
alley will be treated as if it were one side of the street; one composite sample
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from the street gutter on both sides of the alley will be collected, as well as a
single composite sample from each sidewalk or similar area if it exists along each
side of the alley.
In addition to sampling within the abatement area, the same type of sampling will
be done in an approximately 200 ft. "buffer zone" which will surround the
abatement area. This "buffer zone" will also receive exterior dust abatement of
streets, sidewalks, and alleys and will therefore be sampled to determine
abatement effectiveness and recontamination rates.
2. Partially or completely paved parcel sampling.
Exterior surface dust will be collected from paved areas within soil parcels such
as paved walkways. Exterior dust will also be collected from completely paved
parcels such as parking lots. The parcel designations to be used in these areas
will be determined from plat maps. Parcel boundaries will be measured with
surveyor's measuring tape for accuracy. Parcel boundaries and sample lines will
be marked with chalk, if necessary. A composite sample of at least four
subsamples will be collected from an area consisting of 4,000 to 8,000 square
feet. Parcels will be combined or subdivided to achieve the square footage
specified.
3. Samples targeted to subject residences
After subjects are recruited into the study, exterior dust samples will be collected
around the building where study subjects reside. Two samples will be collected
around each building. One sample will be a composite of no less than three
template areas from the sidewalk area adjacent to the main entry of the building.
The second sample will be a composite of areas from the other three sides, if
paved.
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F. Processing of Exterior Dust Samples
Exterior dust sample preparation is the set of procedures necessary to process exterior dust
samples, resulting in a dust sample ready for lead-concentration analysis by means of the
Kevex-XRF instrument. These procedures include obtaining initial sample weights, sample
drying, sieving, splitting large samples, drying to constant weight and final packaging of
samples.
1. Transfer of Custody
Exterior dust samples collected in the Cincinnati Soil Project study areas are
returned to the Main Street field office where custody of the samples is
transferred immediately from the environmental monitors to an individual
designated by the Associate Project Manager for Technical Matters. At the time
of this transfer, the designated person checks each sample collection worksheet
for completeness, legibility, and accuracy. The bags containing the samples are
inspected for label completeness and accuracy and the identifiers on the sample
bag are checked against the identifiers on the sample collection worksheet. Any
discrepancies in this information are addressed at this time.
The dust sample numbers on the bags are then compared with the sample
numbers in the exterior dust log book. The area and book, page, and parcel
numbers in the log book are compared with the book, page, and parcel numbers
on the sample bags. The day's date is written next to the sample number in the
log book and initialed, signifying that all information is correct, complete, and in
custody. The samples will remain in the custody of the field office until they are
transferred to other labs for analysis. After the individual sample bags have been
checked, they are returned to the larger bags in which they were stored during the
collection process. The larger bags are then placed in plastic storage bins for
storage. The samples are stored either in a designated storage area or the soil
preparation lab.
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2. Weighing and Air Drying of Samples
A bag of samples is removed from a storage bin and unpacked. After the sample
bags are removed from the outer plastic bag and placed on the lab bench, a
judgement is made about the size of the plastic-coated drying plate (6" or 10")
necessary to hold the entire sample. After an appropriately-sized drying plate is
selected, both identifiers, the sample number and the book, page, and parcel
information, are written on the bottom of the plate and the sample number is
written on the outer edge of the top of the plate.
At this time, a stainless steel weighing container is placed on the top of the
balance and the balance is set to zero. The sample bag is opened and the
contents are dumped into the weighing container. This operation is performed
under the hood with the exhaust fan running and the sash at the designated
height. The sample and container are returned to the balance and the weight of
the sample, to the nearest 0.0 Ig, is recorded in the exterior dust weight book next
to the corresponding sample number. The sample is then dumped onto the
previously marked plate. The dust is spread evenly over the surface of the plate
with a stainless steel spoon or spatula.
All of the contents of the weighing container are brushed onto the plate to
prevent or reduce loss. The drying plates are placed on a tray for drying and
when a tray is filled with plates it is placed on the drying shelf. Prior to placing
the tray on the drying shelf, a label identifying the date on which the sample was
placed on the tray is attached to the end of the tray so that it is visible from the
front of the drying shelves.
The samples are allowed to dry in this manner for a specified period. Samples
weighing less than 50 grams should dry for three days and samples weighing
more than 50 grams should dry for a period of seven days. At the end of this
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time, each sample is re-weighed in the weighing container. This net dry weight
is then entered into the sample weight book. Pilot studies found this procedure to
be adequate for obtaining constant weight. After these samples are weighed they
can be returned to the drying shelves or sieved.
3. Sample Sieving
Each sample is sieved two times. Once with a number 10 sieve with a mesh size
of 2 millimeters, followed by a number 60 sieve with a mesh size of 250
microns. All sieving takes place under a hood with the exhaust fan operating and
the sash at the designated position. The appropriate sash position is
approximately at the half-open position. The proper position of the sash is
marked on the side of the hood and is approximately eleven inches above the
counter top. With the sash in this position an adequate movement of air at the
hood opening will reduce the probability of exposure to lead dust for lab
personnel.
The first step in the sieving process is to label the sample jars. The sample jars
should be labeled in pairs. Two jars should be labeled with the sample number
recorded on the plate of the sample to be sieved. That number should be
followed by "T" on one jar and "U" on the other jar. The same number should
be written two times on each jar on opposite sides of the jar.
In order to sieve the exterior dust, the 2mm sieve should be placed on top of the
sieve pan. Dump the sample from the plate into the sieve and work the sample
through the sieve until no more material passes through the screen. The material
remaining in the sieve, consisting of rocks, glass, cigarette butts, paper and grass
should be discarded into a box lined with a plastic garbage bag which is inside
the hood. Discarding the material outside of the hood has the potential for
contaminating both personnel and lab. After the material in the sieve has been
discarded, the sieve should be tapped several times on a hard surface and brushed
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out with a paint brush used for that purpose. The outside and the inside of the
sieve should be brushed in order to prevent potential contamination of subsequent
samples.
If the initial sample weighs more than 200 grams, it should be split at this time.
If it is less than 200 grams, the sample can be sieved with the number 60 sieve at
this point.
Stir the sample to homogenize the contents and transfer about one third of the
material from the sieve pan to the jar labeled with the proper sample number
followed by the letter "T", to indicate a "total" fraction. (If the sample weighs
three grams or less, do not split the sample. A minimum of two grams is
required for XRF analysis. Weigh this fraction and record weight) This total
fraction should be capped and set aside. The number 60 sieve is placed on the
top of another empty, clean sieve pan. The material is transferred from the first
sieve pan to the number 60 sieve and the pan is brushed so that any remaining
material in the pan is transferred to the sieve. A stainless steel spoon is used to
move the material around the 250 micron sieve until no more sample will pass
through the sieve. Any sand or other material remaining in the sieve is then
discarded into the lined box within the hood. The material in the sieve pan is
then transferred to the sample jar labeled with the proper number followed by the
letter "U". This part of the sample is considered to be the "urban" fraction of the
dust.
The sieves and the pans should be brushed out with the paint brush provided for
that purpose. This step is necessary in order to prevent contamination of
subsequent samples. Save the drying plate after checking against the numbers on
the sample jars to insure that they correspond to the numbers on the plate. Plates
may be discarded after all samples are analyzed.
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4. Splitting the Sample
If a sample is larger than 200 grams, it should be split to reduce the size to
approximately 100-200 grams. The splitting operation should be performed in the
same location as the sieving operation, under the hood. The exhaust fan should
be operating and the sash should be in the designated position.
In order to split a sample, the material which passed through the 2 millimeter
sieve should be distributed uniformly in the splitting pan or in the hopper pans so
that when the material is poured into the splitter, an approximately equal amount
of material will flow through each chute in the sample splitter. The receiver pans
should be placed under the chute exits on either side of the sample splitter. The
sample should be introduced to the splitter at a rate which allows free flow of the
sample material through the chutes into the pans below. The contents of one of
the receiver pans should be saved and the material from the other pan should be
used for a second splitting if necessary.
The weight of the initial sample will determine the number of times the sample
will be split. The following guidelines should be followed in splitting samples.
a. Samples weighing between 200-400 grams should be split one time.
b. Samples between 400-800 grams should be split two times.
c. Samples between 800-1600 grams should be split three times.
There will very likely be no samples weighing more than 1600 grams. The
sample pans and the sample hoppers should be brushed after every splitting
operation to prevent cross-contamination of samples.
5. Exterior Dust Weights and Calculations
a. Weights to be obtained:
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1) Initial sample before drying (Wl).
2) Weight of sample after it has dried (3-7 days)(W2).
3) Weight of that part of the sample >2mm when sieved; rocks, glass, paper,
grass, etc (W3).
4) Weight of the sample which is removed from the portion passing through
the 2mm sieve identified as the "T" fraction (W4).
5) After the sample has been sieved with the 250 micron sieve, the weight of
that part of the sample which does not pass through the sieve (>250
microns and <2mm) (W5).
6) Weight of the sample which is <250 micron particle size identified as the
"U" fraction (W6).
b. Calculations
1) Weights of the various portions of the sample should add up to
approximately the weight of the sample after it is dry:
W2 = W3 + W4 + W5 + W6
2) To determine the total amount of sample less than 250 microns in particle
size, first calculate the amount of that particle size in the fraction which
was removed and called "T". Add the calculated "U" and W6 to
determine the amount of the sample collected which is less than 250
microns in particle size.
U = W6 x W4 + W6
(W5 + W6)
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VII. Cincinnati Exterior Dust Analysis
A. XRF Analysis
When samples are removed from the field office/lab for analysis by XRF, the sample number
log book will serve to record the transfer of custody. The transfered samples are starred
and the page signed by both the field lab technician and XRF operator at the University of
Cincinnati, Department of Environmental Health. The XRF lab also has its own record of
receipt of samples.
Following receipt, the samples will be prepared for XRF analysis. The portion (2 gm) of the
sample that is placed in a sample cup for analysis by XRF will ultimately be retained, stored
and remain the custody of the XRF lab. However, the custody of the original exterior dust
sample will be surrendered back to the director of the Digestion Lab at the Department of
Environmental Health for storage.
Approximately 2 g of loose dust, less than 250 microns in particle size, will be weighed and
placed into labeled sample cups (Chemplex Industries, Inc., Cat No. 1530), fitted with
windows of 1/4 mil thick X-ray polypropylene film (Chemplex Industries, Inc., Cat No. 425).
The instrument configuration for the Kevex Delta Analyst Energy Dispersive X-ray
Spectrometer is:
1. Kevex Analyst 770 Excitation/Detection Subsystem:
a. X-ray tube: Kevex high output rhodium anode
b. Power supply: Kevex 60 kV, 3.3 mA
c. Detector/cryostat: Kevex Quantum - UTW lithium, drifted silicon. 165 eV
FWHM resolution at 5.9 KeV.
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2. Kevex Delta Analyzer:
a. Computer mainframe: Digital Equipment Corp, PDF 11/73
b. Computer software: Kevex XRF Toolbox II, Version 4.14
c. Disk drives: Iomega Bernoulli box, dual drives, 20 MB
d. Pulse processor: Kevex 4460
e. Energy to digital converter: Kevex 5230
3. Operating conditions:
a. Excitation mode: Mo secondary target with 4 mil thick Mo filter
b. Excitation conditions: 30 kV, 0.5 mA
c. Acquisition time: 100 livetime seconds
d. Shaping time constant: 7.5 microseconds
e. Sample chamber atmosphere: air
f. Detector collimator: Ta
4. Analytical conditions:
a. Escape peaks, but not background should be removed from all spectra.
b. The intensity ratio, defined as the integral of counts in the Pb (LA) window
divided by the integral of the counts in the Mo (KA) Compton scatter window,
should be determined for each spectrum
c. The intensity ratios for the standards should be used to determine a linear least
squares calibration curve.
5. Calibration Standards.
The following Cincinnati Soil Standards will be used to produce a calibration
curve. These standards consist of mixed soil or surface scrapings from many
areas in Cincinnati. The lead content reported here is the average of a triplicate
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determination. These standards were analyzed by a nitric/perchloric acid
digestion, followed by atomic absorption.
ppm Pb
15.0
121
719
704
2030
4576
6. Calibration check:
The 719 and 2030 ppm standards will be used as calibration checks.
B. AAS Analysis
Any exterior dust samples which are processed by acid digestion will be in the Custody of the
Lab Director. Digested samples are sent to the Analytical Section for AAS
Acid digestion for analysis by atomic absorption
1. Weigh an aliquot of 1 g dust into a tared, acid-washed 100 ml beaker.
2. Add 50 ml 7N HN03, cover and digest gently at 95°C for 2 hours, stirring
occasionally. If excessive foaming occurs, remove from the heat periodically
until foaming subsides. Maintain at least 25 ml in the beaker by adding 7N HN03
as necessary.
3. Cool the sample in the hood.
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4. Filter the samples through Whatman #54 paper in glass funnels over 100 ml
beakers. The entire filtration procedure should take place under a hood. Rinse
the beaker and filter paper with 1 M nitric acid to effect a quantitative transfer
and filtering using standard laboratory procedures.
5. Evaporate the samples to near dryness at about 180 ° C.
6. Cool the samples in the hood and then add approximately 3 ml 1M HNO3 using a
pasteur pipette.
7. Return to hot plate and heat to redissolve any paniculate mater in the beaker.
8. Pour into 10 ml graduated cylinders. Using additional 1M HNO3 rinse the beaker
to effect a quantitative transfer to the cylinder.
9. Make the sample up to 10 ml with 1M HNO3.
10. The samples are then submitted to the AAS lab for determination of lead.
11. Funnels and volumetrics will be rinsed between sample runs with distilled
deionized water (3 times) and with 1 M nitric acid (1 time).
12. All unknown samples are first screened by aspirating a sample and determining
the range of sample concentrations at maximum scale expansion. Samples are
then diluted with 1.0 M nitric acid to bring the sample concentration within the
linear range of the instrument. After samples are analyzed the lead concentration
is calculated and the results reported in ppm.
13. When results have been received on a set of samples, the Lab Director will handle
disposal of the acid extracts.
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Yin. Cincinnati Handwipe Sample Collection
Collection of the hand-lead samples is done at the conclusion of each visit to a residence.
Preliminary data indicate that hand dust equilibrates with a given environment within two
hours. Therefore, the location and activities of the children immediately preceding the testing
are important and should be noted.
The person collecting the hand-lead samples must wear disposable gloves. The person
collecting the hand-lead samples will clean his/her own hands with a disposable wipe from a
separate container of wipes kept for this purpose before touching the gloves or other
equipment. Once the gloves have been put on they also should be cleaned well using
additional clean wipes. For each residence, where one or more child's hands may be
sampled, a field blank is taken. This will be done in the following manner. Six wipes are
removed from the container, handled to simulate wiping a child's hands and then placed in a
single bag and submitted for analysis.
Lead in dust on children's hands is sampled by wiping each hand of the child with three
separate commercial Wet-Wipes. All surfaces of the hand, front and back, up to the wrists,
are wiped thoroughly with each of the three wipes. The wipes from each child are
composited in a single scalable bag for transport to the laboratory. The total quantity of lead
is reported in pg lead/pair of hands. These values range from 2 to 50 pg lead/hands in the
Cincinnati Lead Study cohort.
The materials used to collect hand-dust lead are as follows: a commercially available wipe
which contains a number of ingredients is used (Walgreen's Brand Wet-Wipes). A
polypropylene, ziploc-type bag is used to contain the sample. Fisher Scientific Disposable
Latex gloves are worn.
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IX. Cincinnati Handwipe Analysis
Use of a perchloric/nitric mixture is a routine method for digestion of handwipe samples in
Cincinnati's other lead projects. However, in the Soil Lead Projects it is important, for
comparison of results, that the three cities use similar methods for analysis of samples. Since
the capability to handle perchloric acid (perchloric acid fume hood) was not possible in all of
the cities, another method was developed. This method involved acid extraction of hand dust
lead using 1 M nitric acid which was shown to compare well with the perchloric/nitric
technique.
For control purposes, lab blanks (method blanks) for the hand-lead samples consist of six
unused wipes which are digested and analyzed in the same manner as the subject samples.
The wipes used for the blanks are from the same lot of wipes as those used to collect the
samples.
A. Acid digestion of handwipe samples (1M Nitric Acid Extraction)
1. Place each sample in a labeled, acid-washed 800 ml beaker.
2. To each sample, add 100 ml of 1 M nitric acid prepared with deionized water.
3. Swirl each sample for 10 seconds.
4. Cover each sample with a watchglass and allow it to extract at room temperature
for 2 hours.
5. Decant the acid solution from the handwipes into a labeled, acid-washed 250 ml
beaker.
6. Add 50 ml of 1 M nitric acid to the handwipes in the 800 ml beaker.
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7. Swirl the sample for 10 seconds.
8. Decant the acid solution into the same 250 ml beaker to composite the acid rinse.
9. Repeat steps 5,6, and 7 a second time for a total acid solution of about 200 ml.
10. Cover the samples with a watchglass which is elevated above the beaker rim with
glass hooks. (The watchglass must be elevated to prevent "bumping" of the
sample during evaporation).
11. Place the samples on the hotplate at about 250 ° C.
12. Evaporate the samples to dryness.
13. Add about 3-5 ml of 1 M nitric acid to each sample, rinsing the watchglass and
the sides of the beaker.
14. Heat the samples gentry on a hotplate at 120-150 ° C to redissolve lead.
15. Filter samples to remove undissolved material, using the following procedures.
Filtration apparatus:
Whatman # 54 filter paper
Glass funnels
50 ml labeled, acid washed beakers 1M HNO3
a. Fold filter paper and place in funnel Rinse filter paper and funnel with 1M
HNO3 over 50 ml beaker and discard rinse.
b. Shake each sample very well.
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c. Filter each sample in the 50 ml beaker, rinsing tube, paper, and funnel with
1M HNO3
d. Reduce the volume of acid in the 50 ml beaker to 5 ml on a hotplate at 250 °
C.
e. Transfer each sample quantitatively to a graduated 10 ml tube and make up t<
volume.
f. Transfer each sample to a new, labeled polystyrene tube for submission to the
AAS lab.
16. Transfer the sample with 3 rinses of 1 M nitric acid to a labeled, acid-washed 1(
ml graduate tube (Coming Cat. No/ 2972, tolerance + 0.1 ml) and make up to
volume with 1 M nitric acid.
17. Shake each sample very well. Transfer each sample to a new, labeled polystyre
test tube with screw cap.
18. The samples are then submitted to the AAS lab. Results are reported in total
pg/sample.
X. Cincinnati Paint Sampling Protocol Using an XRF Analyzer
A. Background and Selection of Surfaces
The concentration of lead in paint will be determined by using an X-ray fluorescen
* analyzer. Two types of instruments will be used, the XK-2 and the XK-3, both
•manufactured by Princeton Gamma-Tech, Inc. The XK-3 with a range of 0-10 mg
Pb per cm2 will be the primary instrument used. The XK-2 will be a backup and
used in the event a reading on the XK-3 exceeds 10 mg/sq cm2.
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In each residence two surfaces, a painted woodwork and a painted walls in each of
three rooms or areas most frequently occupied by the subject child will be evaluated
(e.g. child's bedroom, kitchen, living room). One reading will be taken at three
different locations on each type of surface. The identity of the rooms and the Pb
found in the paint will be recorded on the worksheet shown in Figure 2. In addition, a
copy of a floor plan of the residence will be available to the technician and on which
the sample location will be noted All unpainted surfaces, such as paneling, wallpaper,
and unpainted woodwork will not be tested. In the event a room selected is unpainted
an alternate room will be selected and this information recorded.
A wall and/or trim immediately exterior to the dwelling unit entry will also be
sampled. The same paint sites on the exterior of a building will only be examined
with the owner's permission.
XRF readings will be taken by placing the instrument on the designated surface and
opening the shutter. (More accurate readings can be obtained from flat surfaces so
curved surfaces will be avoided). Once the shutter is opened the lead content of the
paint will appear as a visual numerical display on the instrument The operator will
read the number for the other team member to record. This will be repeated back to
the operator.
In addition to the XRF readings, a semi-quantitative evaluation of the condition of the
painted surface will be made. The surface will be rated on a scale of 1 to 3
indicating a range from intact, tight paint to extremely deteriorated surfaces. The paint
condition and lead content will be combined to give a weighted paint hazard score
reflecting available lead. The hazard score has been shown to correlate with blood
lead in children.
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B. Operation of the XRF Analyzer to Determine the Concentration of Lead
At the start of each day the performance of the XRF instruments are evaluated using
the procedures as mentioned in "Calibration Procedures and Frequency". Prior to
taking readings at the residence, calibration checks will occur using reference material
prepared by the Department of Housing and Urban Development (XK-2 =1.5 mg/cm2
and 2.99 mg/cm2) (XK-3=0.6 mg/cm2 and 2.99 mg/cm2). After the designated areas in
the home have been sampled and before the team is ready to leave, the instrument's
calibration will once again be checked.
Following is the Operating Procedure for the XK-3 unit:
1. Remove the battery pack, coiled cable, and XK-3 unit from the carrying case.
2. Connect the battery pack to the XK-3 unit, using the coiled cable.
3. Locate the LOCK SWITCH underneath the handle toward the rear of the unit and
push it forward. A red light over the display window will now glow to indicate
that the instrument is ready to perform its analysis as soon as the shutter is
opened.
4. Depress the RED RESET button on the back plate of the unit, just above the coiled
cable connection, and hold for 8-10 seconds.
5. Grasping the wooden handle, position the face-plate of the instrument against the
surface to be measured and push down firmly and evenly on the handle to spring
the shutter open. The red light over the window will now blink to indicate that
the shutter is open and that the measurement is taking place. As soon as the
shutter opens, the previous read-out in the window vanishes, leaving the window
blank except for a single decimal point
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6. Keep the handle firmly depressed until the new read-out appears.
7. When the new read-out appears, release pressure on the handle. The display
window retains read-out until the handle is pushed down again to begin another
measurement.
8. Push the lock switch back to the lock position when readings are completed.
XL Cincinnati Water Analysis
All water samples to be analyzed are from the faucets of the Cincinnati residences. Lead
found in these samples will be dissolved and therefore no digestion of the sample is
necessary. However, total lead will be determined by digesting a portion of each of the 1st
25 samples collected to prove that total lead equals dissolved lead (EPA Method 3020). To
further stabilize the samples and maintian leachable lead in solution, samples will be acidified
to a pH<2.0.
Lead in water will be analyzed on Perkin-Elmer Zeeman/3030 with an AS-60 Autosampler.
This is a dedicated system for performing Graphite Furnace AAS analysis utilizing the
Zeeman effect background correction. The system is comprised of a
microcomputer-controlled spectrometer, a graphite furnace with Zeeman magnet, a
microcomputer-controlled power supply for the graphite furnace and a PR-100 printer for
automatic printing of results.
1. Glassware cleaning
All glassware, including collection bottles, beakers, volumetrics, pipettes, and
sample cups will be cleaned and acid washed prior to use.
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The following procedure is used:
a. Remove written label from glassware with acetone.
b. Soak all glassware in hot soapy water, if possible soak overnight.
c. Wash thoroughly and rinse well (~10X) with hot tap water.
d. Once cleaned and rinsed soak glassware in a 20% nitric acid/deionized water
solution for a minimum of 4 hrs. preferably overnight.
e. Remove glassware and rinse well with deionized water (~5X).
f. Rinse again with distilled/deionized water (2X).
g. On a clean counter put paper down then a few layers of kimwipes and place
clean glassware on here to dry. Some glassware may need to be oven dried.
All new glassware should be rinsed off with deionized water then soaked in
acid bath 4 hrs.
2. Sample acidification
At the end of the each collection day water samples will be acidified at the field
office to contain 0.5% HNO3. To the 125 ml samples 0.63 ml of HNO3 is added.
3. Standards and Reagents Stock standard - 1 mg/L (1 ml of a Certified Lead Nitrate
Reference Solution, Fisher-Scientific SL21-500; 1 mg Pb/ml) in 0.5% v/v
HNOj/distilled-deionized water (Nitric Acid, 70.0-71.0%; Baker Instra-Analyzed,
for trace metal analysis).
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Working standards - 5,25,50,100,150 g Pb/L (0.5, 2.5, 5.0, 10.0, 15.0 ml of stock
standard diluted to 100 ml 0.5% HNO3.
Mg(NO3)2 - 0.1 mg/ml
NH^PCv - 2.0 mg/ml
NBS SRM 1643b- 23.7 ppb Pb
4. Instrument Conditions
Wavelength (nm): 283.3
Slit (nm): 0.7
Tube/site: pyrolytic coated/L'vov platform
Volume injected: 25 1 x 2
Drying temp. (C): 130 (45 sec.)
Ashing temp. (C): 650 (45 sec.)
Atomization temp (C): 1800 (5 sec.)
Cleanout temp. (C): 2600 (2 sec.)
Cool-down (C): 20 (20 sec.)
Pb electrodeless discharge lamp (EDL)
5. Procedure
Each blank, standard and unknown will be prepared prior to injection into the
furnace.
f
a. Add 1 ml of blank, standard or unknown to a clean polyethylene tube with cap.
b. Add 0.1 ml of each of Mg/(NO3)2 and NI^HjPC^ matrix modifiers. Cap and
mix well.
c. Add 1 ml of each to the sample cups previously place in autosampler holder.
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d. Initiate analysis program and analyze samples in the following order. Blank,
Standards (5, 25, 50, 100, 150 g Pb/L, 25 unknowns including 2 SRM 1643b.
Repeat the above analyzing lab duplicates of the same samples. Repeat a third
time only after adding 0.5 ml of the 25 g/L standard to all samples and 0.5 ml
of 0.5% HNOj/distilled-deionized H2O to the blank and standards.
e. Concentration in g/L is automatically calculated.
6. Standard Additions
If matrix effects are suspected because of consistent poor duplication of a sample
and/or poor % recovery then sample concentration may be calculated using the
method of standard additions.
a. Add 1 ml of the H2O sample to each of 6-clean polyethylene tubes with cap.
b. To the blank add 0.5 ml HNCydistilled-deionized H2O, to each of the retaining
tubes add 0.5 ml of 1 of the working standards.
c. Follow above procedure 2-3.
d. Initiate the analysis program. Calculate concentration by extrapolaiton back to
the concentration axis for each set of samples analyzed for a particular H2O
sample.
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APPENDIX B
EXTERNAL QUALITY ASSURANCE/QUALITY CONTROL
I. Quality Assurance for Blood Lead Analysis (CDC) B-l
II. QA/QC for Soil, Dust, and Handwipes (EPA) B-ll
1. EPA Laboratory Preparation B-ll
2. Soil Audit Sample Preparation B-16
3. Dust Audit Sample Preparation B-26
4. Handwipe Audit Sample Preparation B-30
5. Soil, Dust, Wet-Wipe Audit Sample Characterization B-31
6. Audit Sample Window Generation B-35
7. Safety B-37
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APPENDIX B: External Quality Assurance/Quality Control
I. Quality Assurance for Blood-Lead Analysis
(Centers for Disease Control)
A. INTRODUCTION
The Urban Soil Lead Demonstration Project requires blood-lead data of the highest quality.
Expected differences in blood-lead levels from successful abatement are of the order of 2-4
ug/dL, thus placing unusually stringent requirements on long- term laboratory precision. The
quality control issues include establishment and maintenance of a high degree of precision
over the entire duration of the project. The key function of the quality assurance system is to
ensure the absence of any "drift" (downward or upward) with analytical values with time,
such that any difference in blood-lead values over time cannot be attributed to changes in the
analytical system. Simply stated, this will help ensure that statistically speaking, observed
changes in blood-lead are real; that is, due to intervention and not attributable to changes in
the laboratory method over time. Since the CDC has extensive experience in such activities
from the National Health and Nutrition Examination Survey (NHANES) and other long-term
studies, we were asked by the USEPA to provide assistance. The material following is a
summary of laboratory related issues that were included in the overall QC program.
B. ELEMENTS OF A QUALITY CONTROL SYSTEM
In order for any analytical measurements to be valid and interpretable, the sources of error for
each unique measurement system must be identified and minimized, This, then, is the major
function of quality control. In the specific example of blood-lead measurements, the
following have been shown from experience to be the major sources of error:
1) contamination of the specimen during collection, storage, or analysis
2) deterioration of the specimen by clotting, denaturation, or other processes
3) instability of the measurement system, either over a short (within run/day) or long
time span
4) improper calibration of the measurement system
5) errors in data handling, storage, or reporting
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Quality control therefore must include a number of components, both within and external to
the laboratory: 1) collection of an uncontaminated specimen; 2) preservation and shipping (if
needed) of the specimen under conditions that assure integrity; 3) monitoring of analytical
method performance, to include instrumental stability, maintenance, and performance of the
analyst(s); and 4) accuracy and completeness of all data, to include specimen identification,
data reduction, and data interpretation. Some critical components of each of these areas
include:
1. Specimen Collection
Proper screening of all specimen collection equipment to define any detectable levels of the
analyte, and estimate variability of this contamination.
Written protocols for specimen collection which describe in detail all sampling equipment and
its use, precautions to avoid contamination, and other requirements (time of day,
fasting/non-fasting state of subject) which might affect specimen integrity.
2. Specimen Preservation and Shipping
Proper packing, storage and shipping temperatures, suggested means of conveyance for timely
receipt of specimens.
Detailed shipping and specimen log forms to allow description of each specimen to record
any variances from collection or shipping protocols.
3. Analytical Method Performance
The method selected must demonstrate precision and accuracy in the appropriate analytical
range and should be simple, rugged, rapid and cost-effective. Ideally, the detection limit
should be ca. 2 ug/dL with precision about 5% at the 10 pg/dL level for the proposed study.
Instrumental stability, and by inference "method" stability, should be documented by analysis
of control materials, both "bench" and "blind". It is desirable that materials with certified
values of the analyte of interest be analyzed regularly to demonstrate method accuracy. It is
suggested that at least 10% of the specimens be quality control pools.
4. Bench and Blind Quality Control Materials
Blind quality control pools should be inserted at a rate of 5% by a source external to the
laboratory. These specimens should be in the same container type and labelled with
pseudopatient numbers such that they are indistinguishable from patient samples. It is
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suggested that the blind (and bench) pools have two concentrations- one in the "expected"
range of values for the majority of patient samples and one at or near the "decision level" for
undue exposure. It is important that the blind materials be truly blind to the analyst for
maximum effectiveness in the detection of analytical system error. The "pseudopatient"
numbers used in labelling of the blinds will be decoded by the supervisor only, and that
analytical run evaluated on the basis of pre-established control limits.
Use of quality control charts for means (X bar) and ranges (R) is essential; it is suggested that
20 runs be made for characterization of all quality control materials, and that these data be
analyzed by two-way analysis of variance (ANOVA) to produce these charts. These charts
should be in use by the analyst for each run for the evaluation of "bench" or known blood
controls (and by the supervisor for blinds) by use of mean and range control limits, such that
corrective actions needed may be made in a timely way.
Criteria for repeat analytical runs (due to "out of control" condition as indicated by results
from quality control samples) are dependent on the number of pools in the quality control
system.
Inclusion of blind splits (duplicate samples within run, with different identification numbers
such that identification by the analyst is prevented) is suggested at a 5% rate; some split
specimens may be submitted to an external laboratory for verification of accuracy or
comparability. If specimen collection constraints allow, it is recommended that at least 10%
of the specimens be split with an external laboratory.
Criteria should be established as to "acceptable" agreement with the external laboratory.
5. Accuracy and Blanks
Blanks, consisting of samples in which ultrapure water is processed through the entire
analytical procedure, are a useful part of quality assurance. The data from these
determinations can be used to evaluate potential contamination in the laboratory environment
as well as estimate the limit of detection of the analytical method.
Establishment of accuracy through the regular analysis of reference materials or proficiency
testing pools is an essential part of good laboratory practice, and will help establish the
accuracy of the method. The pools used for this accuracy assessment should be as close to
identical to the survey samples as possible.
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6. Data Integrity
Data logging should be performed for each run in approved notebooks or other data forms as
soon as possible following each run. Electronic data entry may be desirable either as an
adjunct to or replacement for "hard copy". It is recommended, however, that instrumental
data be collected on hard copy in such a way that all data can be independently verified or
reconstructed.
Data reduction should be standardized; all records of calculations should be secured and
available for review.
C. DESCRIPTION OF QUALITY CONTROL SYSTEM USED
From previous experience in "long-term" quality control, a system was established that is
similar to that used in the NHANES surveys. The cardinal features of such a system include
written protocols for specimen collection, shipping, and analysis, a systematic screening of all
specimen collection equipment and containers, establishment of statistical "control" limits by
each individual laboratory, and supervision of all QC activities by a local laboratory
supervisor. Since the three laboratories already had QC systems in place, there was a need to
establish a common set of protocols and procedures for the entire project
1. Initial Activities
Each laboratory was provided with a description of the sample collection and shipping
protocols developed at CDC (1), as well as a reprint of our analytical method for blood-lead.
Summary descriptions of the QC system used in NHANES, as well as general descriptions of
the NHANES quality control system were distributed.
Four whole bovine blood pools were collected at CDC, evaluated for lead content, and
aliquoted into 2 mL Vacutainer brand whole blood collection containers (blind pools) or
plastic screw-capped vials (bench pools). The Vacutainer specimen containers (as well as the
plastic vials for the bench controls) were screened by established protocol (1), and had been
purchased in sufficient quantity to allow all thee projects to use them as standard specimen
containers. Pools such as these (whole bovine blood, stabilized with 1.5 mg/mL disbdium
EDTA) have been shown to be stable at least two years at 4 C, the recommended storage
temperature. Data from this screening are presented in Table 1. Aliquots of these four pools
were distributed to the laboratories, and duplicate analysis of the four pools was performed
over a series of twenty analytical runs. The data generated from these analyses were used to
calculate the QC limits for both means (X bar) and ranges of duplicate measurements of these
pools. The method of calculation includled POOL "A" from Standard Reference Material
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(SRM) 955 from the National Institutes of Standards and Technology (NIST). The
calculations are based on two-way analysis of variance (ANOVA) as described by Shewhart
(2,3).
Results of the calculated limits for these four pools were sent to the three laboratories to be
used as pan of the laboratory quality control program. Results of the calculations for the
three laboratories, as well as CDC, are presented in Table 2. The quality control limits could
then be used in two ways:
1) the limits for the "blind" pools were used to evaluate the blind quality control
pools, which were inserted into each analytical run by the supervisor; and
2) the limits for the "bench" pools could be used by the analyst (along with those for
any additional pools) to evaluate the degree of statistical control of the analysis.
Insertion of the "blind" pools was random, using a random number table numbering scheme
presented by Taylor (4), with identical labels as study subject specimens and identical
Vacutainers (2 mL liquid EDTA, lot # 8E014 EXP 5/90). An example of the labelling
system is given in Table 3. If names were provided on the sample labels, then fictitious
names were provided for the "blinds" by the supervisor. The source of names could be
random names from a metro phone book, or any other appropriate source.
2. Calibration
Since three different analytical methods were used in the study, the issue of calibration of the
analytical systems was very important. The CDC recommendation to all three laboratories
was that either SRM 3128 (from NIST) or equivalent aqueous standards for lead be used. In
the case of the graphite furnace AAS methods (Boston and Baltimore), a version of the CDC.
published method was used for analysis, which includes "matrix matched" standards and lead
nitrate aqueous standards. The DPASV method used by Cincinnati (5) includes standards
analyzed by isotope dilution mass- spectroscopy (IDMS). In all three laboratories, the
ultimate test of the accuracy of calibration is generation of accurate values for reference
materials. As can be seen from Table 2, all three laboratories agreed well (within 5%) with
each other, and generated comparable results on the four pools provided by CDC.
3. Interpretation of Data
The quality control system outlined here has multiple uses:
1) evaluation of "day-to-day" statistical control of the analytical system;
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2) verification of analytical performance on "blinds"- known samples inserted in each
analytical run to verify precision
3) evaluation of any "trends" in the analytical performance of the method over time-
either short term (days/weeks) or long term (months/years)
With the use of common rules for the verification of statistical control (4), all the laboratories
would follow a statistically valid and proven method for data evaluation. Any problems not
resolved at the local level were presented to CDC for resolution.
D. RESULTS OF QUALITY CONTROL SYSTEMS
Data from the initial characterization of the four whole blood pools used in this project are
presented in Table 2. Each laboratory can be individually compared as to within-run
precision, among runs precision, and total precision. Using the definition of the limit of
detection as 3 SD(wr) developed by Winefordner (6), the laboratory detection limits may also
be compared.
Of equal importance are the long-term quality control data, especially in terms of time trends.
The Shewhart plots for the three laboratories are presented in Figure 2. As can be readily
seen, no long-term trends in analytical values with time are evident. Statistical tests of the
null hypothesis (that is, a "0" slope of X bar versus time) revealed no statistically significant
trends with time.
The conclusions that can be drawn from these three systems are as follows:
1) comparable values were obtained on common quality control materials, which .
covered the analytical concentration range of interest;
2) laboratory data for blood-lead were produced from analytical systems in statistical
control (as defined by Shewhart); and
3) no statistically significant time trends were observed in the data- that is, the
difference in pre- and post abatement blood-lead values are real and not the product
of unstable analytical systems.
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Table 1 Data from Lead Screening
2 mL Vacutainers (B D lot #8E016 Exp. 5/90) Catalog # 6384
Analytical result N=42 tubes;
soaked overnight (12 hr in 1% v/v nitric acid)
X=0.0964 pg/dL lead (SD=0.0596 pg/dL CV=62%)
3 mL plastic vials (linear polyethylene) Falcon Catalog #
Analytical result N=42 tubes;
soaked overnight (12 hr in 1% v/v nitric acid)
X=0.51 ng/mL Equivalent to 0.025 pg/dL (SD=0.36 ng/mL CV=71%)
Capillary Collection (Butterflies B D Catalog #7251: 7253)
Analytical Results; One mL 1% v/v nitric acid passed through each collector)
N=5 results/collectors each size
X=<0.1 ng/mL (cat 7251)
X=<0.1 ng/mL (cat 7253)
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Table 2 Quality Control Limits- Means and Ranges
LAB POOL
CDC
MD
CN
BOS
MEAN 95% Conf Limits
MEAN RANGE
99% Conf Limits
MEAN RANGE
BLIND 1
BENCH2
BENCH 1
BLIND2
BLIND 1
BENCH2
BENCH1
BLIND2
BLIND1
BENCH2
BENCH1
BLIND2
BLIND 1
BENCH2
BENCH 1
BLIND2
4.6
43.5
1.8
10.7
5.1
45.7
2.0
11.1
3.5
43.3
2.4
8.9
4.0
47.0
0.2
10.6
3.0-6.2
38.2-48.8
1.0-2.5
8.5-12.9
4.2-5.9
43.9-47.6
1.45-2.63
9.6-12.6
1.9-5.1
40.5-46.1
0.9-4.0
7.1-10.7
2.4-5.6
42.9-51.2
-1.2-1.5
8.6-12.5
1.6
2.2
1.4
1.4
0.9
1.1
0.6
1.0
3.2
2.2
2.0
3.1
0.8
2.9
0.8
1.3
2.5-6.7
36.5-50.5
0.8-2.7
7.8-13.6
4.0-6.2
43.3-48.2
1.27-2.8
9.2-13.1
1.4-5.6
39.6-46.9
0.4-4.5
6.5-11.2
1.9-6.1
41.6-52.6
-1.6-1.9
8.0-13.1
2.1
2.9
1.9
1.8
1.1
1.5
0.8
1.4
4.2
2.9
2.6
4.1
1.0
3.8
1.1
1.7
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Table 3 Labelling System for Blinds
RUN NUMBER
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
SPECIMEN NUMBERS
1-25
26-50
51-75
76-100
101-125
126-150
151-175
176-200
201-225
226-250
251-275
276-300
301-325
326-350
351-375
376-400
401-425
426-450
BLIND SPECIMENS (L)
OR(H)
10(L) 15(H)
26(L) 50(L)
51(H) 52(L)
84(L) 96(H)
107(H) 118(L)
136(L) 137(H)
158(L) 159(H)
185(H) 195(H)
204(L) 214(L)
232(L) 239(H)
264(L) 266(L)
286(L) 298(L)
301(H) 317(H)
328(L) 348(L)
374(L)359(H)
394(L) 399(H)
404(L) 417(H)
427(H) 431(H)
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E. REFERENCES:
1) "Lake Couer d'Alene Idaho Cadmium and Lead Study-Specimen Collection and
Shipping Protocol" Division of Environmental Health Laboratory Sciences,
Center for Environmental Health, Centers for Disease Control, Atlanta, GA
30333 8/6/86.
2) "Determination of Lead in Blood Using Electrothermal Atomization Atomic
Absorption Spectrophotometry with a L'vov Platform and Matrix Modifier",
D.T. Miller, D.C. Paschal, E.W. Gunter, P.E. Stroud, and J. D'Angelo, Analyst,
112, pp 1701-4(1987).
3) "A Multi-Rule Shewhart Chart for Quality Control in Clinical Chemistry", J.O.
Westgaard, P.L. Barry, and M. R. Hunt, Clinical Chemistry. 27, pp. 493-501
(1981).
4) "A Quality Assurance Program for Health and Environmental Chemistry", M.A.
Gaultier and E.S. Gladney, American Laboratory, pp. 17-22, July 1987.
5) "Elements of Sequential Analysis" Chapter in Biostatistics, A.E. Lewis, ed.
Reinhold Publishing Corp., New York, 1966.
6) "Quality Assurance of Chemical Measurements", John Taylor, Lewis Publishers,
Chelsea, MI 1987.
7) "Anodic Stripping Voltammetry Procedure Modified for Improved Accuracy of
Blood Lead Analysis", S.M. Roda, RJD. Greenland, R.L. Bomschein, and P.B.
Hammond, Clinical Chemistry. 34, pp. 563-7 (1988).
8) "Limit of Detection- A Closer Look at the IUPAC Definition", GJL Long and
J.D. Winefordner, Analytical Chemistry, 55, pp 712A-724A, (1983)
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II. QA/QC for Soil, Dust, and Handwipes (US EPA/EMSL/LV)
Section 1
Preparation Laboratory Operations
1.1 Sample Receipt
Three cities are involved in the Lead Abatement Program; Baltimore, Boston, and Cincinnati.
EMSL-LV supplies the field samplers in each city with 30-gallon plastic barrels for soil
samples and 1-gallon metal containers for interior dust samples. A minimum of two soil and
two dust samples are collected in each city and shipped to EMSL-LV. The preparation
laboratory manager records the arrival date of all samples received.
1.2 Sample Labeling
1.2.1 Soil and Dust
Each soil sample is labeled and identified by a unique sample code as described below.
Example:
A BOS H 01 001
1 234 5 67 8-10
Digits Representation
1 Sample type - "A" = audit "C" = calibration
2-4 City code - "BOS", "BAL", "CIN"
5 Concentration - "H" = high, "M" = medium/'L" = low
6-7 2 kg sample - represents number of the 2 kg container in which soil was
subsampled. If sample is dust the number would represent the lOOg
container.
8-10 20 g aliquot - numbered aliquot from soil 2 kg container or 2g aliquot
from dust 100 g container.
Analytical laboratories at each city provide sample labels and containers to be used for that
city. Prior to shipping, the EMSL labels are removed and the city labels are affixed to the
sample containers. Also, the EMSL-LV codes and corresponding city codes are recorded in a
log book for each sample.
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1.2.2 Hand wipes
Each handwipe sample is labeled and identified by a unique sample code as described below.
Example:
A BOS H 001
1 234 5 6-8
Digits Representation
1 Sample type - "A" = audit "C" = calibration
2-4 City code - "BOS", "BAL", "CIN"
5 Concentration - "H" = high, "M" = medium,"L" = low
6-8 Internal ID - the last three numbers of the internal LESC ID.
Analytical laboratories at each city provide sample labels and containers to be used for that
city. Prior to shipping, the EMSL labels are removed and the city labels are affixed to the
sample containers. Also, the EMSL-LV codes and corresponding city codes are recorded in a
log book for each sample.
1.3 Sample Tracking
1.3.1 Soil and Dust
The preparation laboratory manager tracks each sample as it progresses through the
preparation procedures and records progress in a logbook.
The following information is recorded on a daily basis.
Sample Type - soil, interior dust
City - Boston, Baltimore, Cincinnati
Concentration - high, medium, low
Dried - whether sample has been dried (yes/no)
Crushed - whether sample has been crushed (yes/no)
Bulk homogenization - Whether bulk sample has been homogenized (yes/no)
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Pulverized - whether sample has been pulverized (yes/no)
2 kg split - Whether bulk sample has been split into 2 Kg samples. If this
step is partially complete, the number of aliquots prepared will be recorded.
100 g split - Whether 2 kg soil aliquots have been split into 100 g aliquots or
whether the bulk dust sample have been split into 100 g aliquots. If this step is
partially complete, the number of aliquots prepared will be recorded.
20 g split - Whether 100 g soil aliquots have been split into 20 g aliquots or
100 g dust aliquots have been split into 2 g aliquots. If this step is partially
complete, the number of aliquots prepared will be recorded.
The appropriate types of information will be made available for dust and handwipe samples.
As aliquots are sent to analytical laboratories, this information will also be recorded (see
sample shipment).
1.3.2 Handwipes
The preparation laboratory manager tracks each sample as it progresses through the
preparation procedures and records progress in a logbook.
The following information is recorded on a daily basis.
• Sample Type - handwipe
• City - Boston, Baltimore, Cincinnati
• Concentration - high, medium, low
• Spiked - whether sample has been spiked (yes/no)
The appropriate types of information will be made available for dust and handwipe samples.
As aliquots are sent to analytical laboratories, this information will also be recorded (see
sample shipment).
1.4 Sample Custody
Custody is transferred from the field samplers to the preparation laboratory manager when the
samples are received. The samples remain in the custody of the preparation laboratory
manager until they are shipped to the analytical laboratories.
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1.5 Sample Storage
All samples are placed in cold storage upon receipt until there is room for them in the drying
room. After air drying, the samples are returned to cold storage until processing.
1.6 Sample Shipment
As samples are shipped, a shipping form (Figure 1.1) is sent to both the laboratory manager
and QA manager. The form sent to the laboratory manager contains only the types and
numbers of samples sent and the city sample code information for each sample. The form
sent to the QA manager contains information as well as the EMSL sample code, which
identifies the concentrations of each sample.
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LEAD ABATEMENT QA SAMPLE SHIPMENT FORM
LAB SAMPLE TYPE
Sample
Number.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
bAlLri
1JATE bHlffED
NO OF bAMPLtb'
City Sample Code
EMSL Sample Code
Figure 1.1 Lead Abatement Sample Shipment Form
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Section 2
Soil Audit Sample Preparation Procedures
2.1 Overview
Specific areas of the preparation laboratory are designated for sample processing. Sample
integrity during processing is ensured by: (1) the use of detailed sample labels, (2)
documenting the status of each sample during the processing, (3) following the preparation
protocols, and (4) avoiding physical or chemical contamination during each processing step.
Bulk soil samples are processed as outlined in Figure 2.1. Each step is detailed in sections
2.2 - 2.8.
SOIL SAMPLE
I DR* I
SIEVE
20MM
FRACTION
DISCARD
> 20MM
CRUSH
<20MM
FRACTION
PULVERIZE SAMPLE
TO 0.25MM
HOMOGENIZE (
SUBSAMPLE 2000
GRAM ALIQUOTS
HOMOGENIZE I
SUBSAMPLE 100
GRAM ALIQUOTS
HOMOGENIZE I
SUBSAMPLE 20
GRAM ALIQUOTS
BATCHING (
SHIPMENT
Figure 2.1 Soil Audit Sample Preparation Flow
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2.2 Sample drying
2.2.1 Summary
Sample tables constructed of PVC and heavy nylon mesh are used to air dry the samples.
Use of the mesh enhances air circulation and increases the rate of sample drying. These
tables are located in a dust free drying room.
Chemicals as well as food, drinks and smoking are prohibited in the drying area. A separate
pair of gloves is worn when handling each sample. Care is exercised during the cleaning
operation to avoid contamination of samples. Only one sample at a time is dried to avoid
cross contamination. Weekly vacuuming or sweeping is performed to clean the floors of the
drying room. Sweep EZ, (a sweeping compound) is used at least once a week to control dust
accumulation in the drying area.
2.2.2 Equipment:
Drying tables with nylon mesh surface
Kraft paper, 36-inch wide rolls
Rubber gloves, unpowdered
2.2.3 Procedure
Label a bulk sample processing data form for each sample to be air dried. Place two fresh
sheets of kraft paper, approximately 1 square meter in area, on the drying table. Wearing
gloves, slowly spread the sample on top of the of paper, taking care not to lose any soil off
the paper or contaminate any adjacent samples. Disaggregate any large peds. Soils high in
clay may harden nearly irreversibly if allowed to dry without a preliminary disaggregation of
medium and coarse peds. Place an additional sheet of kraft paper loosely over the sample.
Daily stir the soil sample to facilitate drying. During the first few days replace the bottom
sheet of paper in order to alleviate excessive moisture accumulation. Note any observations
of fungal or algal growth on the data form.
Allow the sample to air dry for a minimum of four days. Prior experience indicates that
samples dry to a constant moisture content (1-2.5%) within three days at the EMSL-LV
preparation laboratory.
2.2.4 Quality Control
When samples are received, labels are checked and recorded. Wearing gloves, the samples
are spread out on kraft paper, which is an effective barrier separating the samples from the
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PVC mesh tables. A cover sheet of kraft paper is used to reduce potential contamination.
When handling the samples, gloves are always worn.
2.3 Initial Disaggregation and Sieving
2.3.1 Summary
When a bulk soil sample is air dry, it is disaggregated and sieved in order to remove large
rock fragments and to prepare the sample for crushing, pulverization, homogenization and
subsampling. This procedure is accomplished in two steps: (1) disaggregation and sieving
through a 20-mm sieve and, (2) crushing, pulverizing, and sieving through a 2-mm sieve.
2.3.2 Equipment:
Fumehood
Kraft paper
Plastic bags
Respirator
Rolling pin
Rubber stopper
Tyvek suit
2mm sieve
20mm sieve
2.3.3 Procedure
Place aim2 sheet of kraft paper on the sieving table under a vented fumehood Place a 60
cm2 sheet of kraft paper on the larger piece of paper and spread a portion of one bulk sample
within the confines of the 60 cm2 sheet. Carefully examine the nature of the rock fragments
within the sample and determine the amount of pressure necessary in order to disaggregate
the soil peds without fracturing or crushing the fragments. Place another 60 cm2 sheet of
kraft paper over the sample and gently roll the rolling pin across the sample. Enough force
should be applied to break up the peds, but not so much that weathered rock fragments are
crushed. Place this crushed sample in the 20-mm mesh sieve and push the soil through the
sieve with a rubber stopper onto the kraft paper. Attempt to include any soil adhering to rock
fragments. Place the sieved material in a clean container and repeat the process until all of
the soil of from one bulk sample is sieved. All rock fragments and other material larger than
20-mm is placed in a plastic bag and properly discarded.
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Crush the minus 20-mm fraction (The Crushing procedure is described in section 2.4) then
passed through a 2-mm sieve using the procedure described above.
The sieves are cleaned after each sample by tapping the sieve on a hard surface and brushing
out the sieve to expunge any remaining soil particles.
2.3.4 Quality Control
The disaggregation and sieving areas should be covered with kraft paper and cleaned after
each sample has been sieved. When sieving, gloves must be worn, as well as an appropriate
mask and protective clothing. The laboratory manager will frequently check the sieving
operation for proper equipment and for adherence to protocol. A member of the EMSL-LV
QA staff will visit the preparation laboratory to ensure adherence to protocol.
2.4 Crushing
2.4.1 Summary
After soils are sieved through the 20-mm sieve, the < 20-mm material is passed through a
rock crusher. The intent of crushing is to further reduce the particle size to < 2mm.
2.4.2 Equipment
Brush
Compressed air
Crusher
Gloves
Mask
Protective Clothing
Plastic bags
Scoop
2-mm sieve
2.4.3 Procedure
With a scoop, place a portion of the minusm soil fraction to the crusher opening. Turn the
crusher on. The crusher deposits the resulting crushed material into a collection bin at die
bottom of the machine. After the first scoop is crushed, shut the machine off and sieve the
crushed material through the 2-mm sieve (described in Section 2.4). If all the material passes
through this sieve, the crushing plates are sufficiently close enough to continue processing. If
not, adjust the plates and repeat the procedure on the same sample until all the material
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passes through the 2-mm sieve. Once the collection bin is full, turn the machine off and
deposit the material into a clean labeled plastic bag. Repeat the operation until all soil from
one bulk sample is crushed. Thoroughly clean the machine with compressed air and a brush
between samples.
2.4.4 Quality Control
When crushing, gloves must be worn, as well as a mask and protective clothing. The
machine opening should be tightly fastened to minimize dust The laboratory manager will
frequently check processing equipment for proper operations, for adherence to protocol
including proper maintenance. A member of the EMSL QA staff will visit the preparation
laboratory to ensure adherence to protocol.
2.5 Pulverizing
2.5.1 Summary
The routine soil samples that are analyzed by the cities are ground to a particle size of less
than 0.25mm. Therefore, it is necessary to provide audit materials with the same particle size
fraction. The preparation laboratory pulverizes the minus 2-mm soil fraction to a particle size
of less than 0.25mm.
2.5.2 Equipment
Brush
Compressed air
Gloves
Mask
Plastic bags
Protective Clothing
Pulverizer
Scoop
0.25mm sieve
2.5.3 Procedure
With a scoop, place a portion of the minus 2-mm soil fraction material into the pulverizer
opening. Turn the power on. The pulverizer grinds the soil and deposits it into a collection
bin at the bottom of the machine. After the first scoop is pulverized, shut the machine off
and sieve the material through the 0.25-mm sieve. If all the material passes through this
sieve, the grinding plates are sufficiently close enough to continue pulverization. If not,
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adjust the plates and repeat the procedure on the same sample until all the material passes
through the 0.25-mm sieve (described in Section 3.6). Once the collection bin is full, turn the
machine off and deposit the pulverized material into a clean labeled container. Repeat the
operation until all soil is pulverized. Thoroughly clean the machine with compressed air and
a brush.
2.5.4 Quality Control
When pulverizing, gloves must be worn, as well as a mask and protective clothing. The
machine opening should be tightly fastened to minimize dust. The laboratory manager will
frequently check the processing equipment for proper operation, for adherence to protocol
including proper maintenance. A member of the EMSL QA staff will visit the preparation
laboratory to ensure adherence to protocol.
2.6 Final Sieving
2.6.1 Summary
To ensure that the pulverized audit sample has a particle size < 0.25mm it is resieved through
a 0.25mm sieve.
2.6.2 Equipment
Fumehood
Kraft paper
Paint Brush
Plastic bags
0.25-mm sieve
3x5 card
2.6.3 Procedure
Place aim2 sheet of kraft paper on the sieving table under a vented fumehood. Place a 60
cm2 sheet of kraft paper on the larger piece of paper. Place a portion of the soil material in
the 0.25-mm sieve and screen the material using a rocking motion. Use a paint brush or 3 x
5 card to gently push the material through. Place any material > 0.25mm into a separate pile.
Continue this procedure until the complete sample is sieved. Save the material not passing
through the .25mm sieve for further pulverization.
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2.6.4 Quality Control
When sieving, gloves must be worn, as well as a mask and protective clothing. The
laboratory manager will frequently check the sieving processing equipment for proper
operation and for adherence to protocol. A member of the EMSL-LV QA staff will visit the
preparation laboratory to ensure adherence to protocol.
2.7 Homogenization and Subsampling to 2-kg Aliquots
2.7.1 Summary
Prior to splitting the 2 kg aliquots into 20 g aliquots, the bulk soil (minus 0.25mm fraction) is
homogenized using a combination of three techniques; drum-rolling, cone and quartering, and
riffle-splitting. After homogenizing, the bulk sample is split into 2 kg aliquots using a riffle
splitter.
2.7.2 Equipment
Drum homogenizer
Gloves
Kraft paper
Labels
Large riffle splitter
Mask
Protective clothing
Shovel
Top loading balance
2-L sample bottles
2.7.3 Procedure
2.7.3.1 Drum homogenization/Cone and Quartering
Place all of the < 0.25mm fraction from one soil sample into the drum homogenizer. Slowly
rotate the drum for five minutes. Pour the entire sample onto a large piece of kraft paper so
that the sample takes on the shape of a cone. Homogenize the cone by dividing the cone into
four equal quarters by lines going clockwise from 1 to 4. Using a shovel, remove the first
quarter to form a new cone. The third, second and fourth quarters are piled sequentially over
the first quarter. This procedure is performed seven times in succession.
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2.7.3.2 Riffle splitting
Position the two collecting bins under the large riffle splitter (Figure 2.3). Pour the entire
sample evenly across the baffles of the riffle splitter. Transfer the soil from each collecting
bin into the distribution pan and replace the receiving pans under the riffle splitter. Repeat
this procedure five times in
succession.
2.7.3.3 Subsampling
After the homogenization, 2 kg aliquots are obtained. If the cone and quartering technique is
used, place a clean 2-L sample bottle at the bottom of the cone and, with an upward
movement, collect a sample weighing approximately 2000 grams (+/- 20 grams). If the riffle
splitting technique is used, place a clean 2-L sample bottle at one end of the collecting bin
and moved to the other end to fill the bottle. The sample is labeled using the procedure
described in Section 2.2. The first 2 kg aliquots for each audit concentration is identified
with "01" and subsequent aliquots numbered consecutively. The other information within the
sample code will ensure a unique sample identity. Repeat this procedure for the entire amount
of homogenized audit sample. Store the audit samples in cold storage until further
processing.
2.7.4 Quality Control
When homogenizing, gloves must be worn, as well as a mask and protective clothing.
Prepare labels for the 2 kg samples prior to the processing step in order to avoid mislabeling.
The laboratory manager will frequently check the homogenization operation for proper
processing equipment and for adherence to protocol. A member of the EMSL-LV QA staff
will visit the preparation laboratory to ensure adherence to protocol.
2.8 Homogenization and Subsampling to 100 g and 20g Aliquots
2.8.1 Summary
Each 2 kg aliquot prepared in section 2.7 is further homogenized in a medium sized riffle
splitter and split into 100 g aliquot The 100 g aliquots are then homogenized in a small
riffle splitter and split into 20 g aliquots. These two procedures arc done simultaneously in
order to avoid the use of intermediate sample containers and the possibility of mislabeling.
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2.8.2 Equipment
Gloves
Fumehood
Laboratory containers (20 g samples)
Open pan balance
Plastic bags
Riffle splitters, medium ( 24 chute 13-1/2" x 15-3/8") and
small (32 chutes 6-5/8" x 9")
Scoop
2.8.3 Procedure
2.8.3.1 Homogenization and Subsampling to 100 grams
2.8.3.1.1 Initial Homogenization-- Position the two receiving pans under the medium riffle
splitter. Pour the entire 2 kg sample evenly across the baffles of the riffle splitter. Transfer
the soil from each receiving pan into the distribution pan and replace the receiving pans under
the riffle splitter. Repeat this procedure five times in succession.
2.8.3.1.2 Splitting to 500 g Aliquots- Pour the sample evenly across the baffles and place
the soil from one receiving pan aside. Transfer the soil in the other receiving pan to the
distribution pan and split once more. This should produce approximately a 500 g samples in
each receiving pan. Place these samples on separate sheets of kraft paper. Split the soil from
the other receiving pan similarly. This produces a total of four 500 g aliquots from each 2kg
aliquot.
2.8.3.1.3 Splitting to 100 g Aliquots-- Pour the 500 g sample evenly across the baffles and
place the soil from one receiving pan into a plastic bag. Transfer the soil in the other
receiving pan to the distribution pan and continue splitting as necessary until approximately
100-g of soil occupies one of the receiving pans. Place the entire contents of this pan into
the distribution pan of the small riffle splitter (see section below). Repeat the procedure until
all of the 2 kg aliquot is split into 100 g aliquots.
2.8.3.2 Homogenization and Subsampling to 20 grams
2.8.3.2.1 Initial Homogenization-- Position the two receiving pans under the small riffle
splitter. Pour the entire 100 g aliquot from the distribution pan evenly across the baffles of
the riffle splitter. Transfer the soil from each receiving pan into the distribution pan and
replace the receiving pans under the riffle splitter. Repeat this step five times hi succession.
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2.8.3.2.2 Splitting into 20 g Aliquots-- Pour a 100 g aliquots evenly across the baffles of the
small riffle splitter. Place the soil from one receiving pan into a plastic bag. Transfer the
soil from other receiving pan to the distribution pan and continue splitting as necessary until
approximately 20 g of soil occupies one of the receiving pans. Place the entire contents of
the pan into the pre-labeled sample container provided by the analytical laboratories. Repeat
the procedure until the entire 100 g sample is split into five 20 g aliquots.
2.8.4 Quality Control
When homogenizing and subsampling, gloves must be worn, as well as a mask and protective
clothing. The laboratory manager will frequently check the operation for proper use of
equipment and for adherence to protocol. A member of the EMSL QA staff will visit the
preparation laboratory to ensure adherence to protocol. As samples are characterized,
precision estimates for each audit sample type will be developed. If the pooled relative
precision estimate (RSD) for an audit sample whose concentration is above 10 times the
detection limit (~100ppm) is greater than ten percent, the preparation laboratory will combine
all 20 g aliquots, rehomogenize, then resplit the sample.
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Section 3
Dust Audit Sample Preparation Procedures
3.1 Overview
Dust samples of different concentrations will be supplied to EMSL-LV from each city. From
these samples, EMSL-LV will provide three audit samples with Pb at low, mid, and high
concentration ranges and three calibration standards at similar concentrations. The bulk
samples are air dried, sieved, homogenized and split into 2-gram aliquots as outlined in
Figure 4.1. Participating laboratories supply EMSL-LV with sample containers, labels, and
the appropriate labeling techniques for the samples.
A random subsample of the audit samples will be characterized by EMSL-LV. Fifty samples
at each concentration range will be analyzed for Pb by XRF. A subset of these samples will
be analyzed by ICPES after nitric acid extraction. Characterization data will be supplied to
the Lead Abatement QA manager.
DUST SAMPLE
HOMOGENIZE «
SUBSAMPLE 100
GRAM ALIQUOTS
HOMOGENIZE t
SUBSAMPLE 2
GRAM ALIQUOTS
BATCHING I
SHIPMENT
Figure 3.1 Dust Audit Sample Preparation Flow
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3.2 Sample drying
Interior dust audit samples will be sent from the participating cities of Boston, Baltimore and
Cincinnati in one gallon containers. Upon arrival, remove the lid of each container and
allowed it to air dry before further preparation. The samples are kept in the shipping
container during air-drying to prevent loss of sample.
3.3 Sieving to 0.25mm
3.3.1 Equipment
Fumehood
Kraft paper
Paint brush
0.25mm Sieve
3x5 index cards
3.3.2 Procedure
Place aim2 sheet of kraft paper onto the preparation table. On top of this sheet place a 60
cm2 sheet of kraft paper. Set a 0.25mm mesh sieve on top of the smaller sheet of kraft paper.
Portions of the dust sample are placed into the sieve and gently pushed through with either a
paint brush or a 3 x 5 card. Material greater than 0.25mm is placed in a plastic bag for
proper disposal.
3.4 Homogenization and Subsampling to 2 Gram Aliquots
Each bulk dust sample is homogenized in a medium sized riffle splitter and split into 100 g
aliquots and then these 100 g aliquots are homogenized in a mini riffle splitter and split into 2
g aliquots.
3.4.1 Equipment
Fumehood
Gloves
Laboratory containers (2 gram samples)
Open pan balance
Plastic bags
Riffle splitter, medium (24 chute 13-1/2" X 15-3/8")
Riffle splitter, mini (14 chutes, 2-1/16" x 3-3/4")
Scoop
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3.4.2 Procedure
4.4.2.1 Homogenization and Subsampling to 100 grams
Position the two receiving pans under the small riffle splitter. Pour the entire contents of the
minus 0.25mm dust fraction evenly across the baffles of the riffle splitter. Transfer the dust
from each receiving pan into the distribution pan and replace the receiving pans under the
riffle splitter. Repeat this step five times in succession with the material in each receiving
pan.
Pour the sample evenly across the baffles and place the dust from one receiving pan into a
plastic bag. Transfer the soil in the other receiving pan to the distribution pan and continue
splitting as necessary until approximately 100 g of dust occupies one of the receiving pans.
Place the entire contents of this pan into the distribution pan of the mini riffle splitter (see
section below). Repeat the procedure until all of the dust sample is split into 100 g aliquots.
3.4.2.2 Homogenization and Subsampling to 2 Grams
Position the two receiving pans under the mini riffle splitter. Pour the 100 g dust aliquot
evenly across the baffles of the riffle splitter. Transfer the dust from each receiving pan into
the distribution pan and replace the receiving pans under the riffle splitter. Repeat this step
five times in succession with the material in each receiving pan.
Splitting to 25 g Aliquots--
Pour the 100 g aliquot evenly across the baffles and place the dust from one receiving pan
aside. Transfer the dust in the other receiving pan to the distribution pan and split once more.
This produces a 25 g aliquot in each receiving pan. Place the 25 g aliquots on separate sheets
of kraft paper. Similarly split the remaining dust to produce an additional a total of two 25 g
aliquots.
Splitting to 2 g Subsamples--
Pour the 25 g aliquot evenly across the baffles of the miniriffle splitter and place the soil
from one receiving pan into a plastic bag. Transfer the soil in the other receiving pan to the
distribution pan and continue splitting as necessary until approximately 2 g of soil occupies
one of the receiving pans. Place the entire contents of the this pan into the pre-labeled
sample container provided by the analytical laboratories. Similarly split the dust set aside in
the plastic bag. Repeat the procedure until all of the 25g aliquots are split into 2 g samples.
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3.4.3. Quality Control
When homogenizing and subsampling, gloves must be worn, as well as a mask and protective
clothing. The laboratory manager will frequently check the seiving operation for proper
equipment and for adherence to protocol. A member of the EMSL QA staff will visit the
preparation laboratory to ensure adherence to protocol. As samples are characterized,
precision estimates at each concentration will be developed. If the pooled precision estimate
for an audit sample whose concentration is above 10 times the detection limit (~100ppm) is
greater than ten percent relative standard deviation, the preparation laboratory will and resplit
rehomogenize the sample.
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Section 4
Hand wipe Audit Sample Preparation
4.1 Summary
As part of the Lead Abatement Program, childems' hands are swabbed with handwipes which
are then analyzed for lead. As part of the quality control, handwipes audit samples are
included with the unknown handwipe samples for analysis. Handwipe audit samples are
spiked with lead at three different levels; 5pg, 20pg, and 40ug lead.
4.2 Equipment
Box of wet handwipes
200 mg/L and 1000 mg/L lead solutions
ml pipette
Ziploc type plastic bags
Plastic gloves
4.3 Procedure
4.3.1 Reagents
• 1000 mg/L Pb - Certified standard obtained commercially.
• 200 mg/L Pb - Dilute 1000 mg/L Pb solution 1:5 with reagent water.
4.3.2 Spiking Procedure
• Unopened containers of wet-wipes are provided by the participating cities,
• Working in a laminar flow clean hood, wearing clean gloves, Pull out 6 wet
wipes from the same container and place into a stack (Le., one on top of the
other). Using a micropipet, add the spike to the center of the wet wipe stack
(between the third and fourth wipe). The spike volumes are given below;
- 5 pg spike - 25 pL of 200 mg/L Pb standard
- 20 pg spike - 20 pL of 1000 mg/L Pb standard
- 40 pg spike - 40 pL of 1000 mg/L Pb standard
• Fold and crumple the wet wipe stack and place into a zip-lock bag. Seal and label
the bag with lab ID number. Record the lab ID and spike level into a lab notebook.
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Section 5
Urban Soil, Urban Dust, And Wet-Wipe
Audit Sample Characterization
5.1 Sample Preparation
5.1.1 Reagents
Concentrated nitric acid (ACS Reagent grade)
Concentrated nitric acid (Double deionized)
Hydrofluoric acid (48% high purity)
Reagent water (ASTM type H)
5.1.2 Hot nitric Acid (HNO3) Extraction
Place 1 g sample (weighed to nearest 0.1 mg) or packet of wet wipes into a clean 100 mL
beaker. Add 50 mL 7N HNO3 to soil or dust samples. Add 50 mL IN HNO3 to wet wipe
samples. Push wet wipes down with glass stirring rod to ensure complete coverage. Cover
with a watch glass and heat gently at 95°C for 2 hours. Maintain at least 25 mL volume in
the beaker by adding 7N HNO3 (IN for wet wipe samples) as necessary. After digesting,
cool and add 10 mL of water. Filter through Whatman No. 1 filter paper into a 100 mL
volumetric flask. Rinse beaker and filter with additional water. Dilute to volume with water.
5.1.3 Total Digestion of Urban Soil and Dust Samples
Add 0.5g (weighed to nearest 0.1 mg) sample into a clean teflon microwave
digestion vessel. Add 9 mL of concentrated HNO3, and 4 mL of 48 % HF. Cap
and seal the vessels. Weigh capped vessel to the nearest .Olg and place in
microwave oven. A total of 12 vessels must be placed in oven. Use blanks if
extra spaces must be filled. Heat at 520 Watts for 30 minutes. Let the samples cool
and irradiate again at the same setting.
CooL Weigh capped vessels. Rinse condensate from cap and vessel walls into
vessel. Transfer quantitatively to a 100 mL polypropylene volumetric flask. Dilute
with reagent water to the mark.
If not determined previously, determine percent solids as in Section 6.2.
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5.1.4 Preparation of Loose Powder Samples for XRF Analysis
• Pour a 5g soil sample or 2 g dust sample into a powder cup and seal with 3.6 um
mylar film.
5.2 Percent Solid Determination
Determine the percent solids in the soil or dust samples by drying a 5g aliquot at 105°C for
24 hours. Place a 5g sample (weighed to the nearest mg) in a tared aluminum weighing
dish. Dry at 105°C for 24 hours. Cool in a desiccator. Reweigh to the nearest mg.
Percent solids = [100 (wet wt. - dry wt.) /wet wt.].
5.3 Sample Analysis
5.3.1 Summary
Samples were analyzed by XRF to determine Pb concentrations and homogeneity. The XRF
soil audit concentrations were verified by ICP or GFFAAS. From the fifty aliquots of each
soil analyzed by XRF, a subset of 7 aliquots were analyzed by ICP or GFAAS.
5.3.2 ICPAES and GFAAS Analysis
The acid digests are analyzed by either ICPAES or GFAAS depending on the lead
concentration in the digestate. Solutions containing Pb concentrations greater than 10 times
the ICPAES IDL are analyzed by ICPAES (IDL is about 50 ppb). Lower concentrations are
measured by GFAAS. The instruments are calibrated and the digestates analyzed. HF
resistant components are used for the total digest solutions. Quality control is described in
Section 5.5.
5.3.3 XRF Analysis
Loose powder samples are analyzed by XRF. The analysis conditions for lead are; Ag
secondary target, X-ray tube voltage = 35 Kev, X-ray tube current = 3 mA, atmosphere = air,
counting time = 200 sec. live time. The lead L-beta peak/ Ag compton peak ratio is
calculated. The lead concentration is determined from the ratio and the calibration curve .
(Ratio vs. Concentration). Quality control is described in Section 6.5.
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5.4 Instrument Calibration
5.4.1 ICPAES and GFAAS Analysis
The instruments are calibrated following the manufacturer's guidelines. A series of
calibration standards are analyzed and a calibration line calculated using linear regression of
intensity vs. standard concentration.
5.4.2 XRF Analysis
The XRF is calibrated by acquiring spectra from a series of urban soil standards with known
lead concentrations. Acquisition conditions are given in Section 5.3.3. The Pb L-beta peak
and Ag compton peak are measured from the spectra and the Pb LB peak/Ag Compton peak
ratios are calculated. A calibration line is calculated using linear regression of ratio vs.
standard concentration.
5.5 Quality Control
5.5.1 Sample Related Quality Control
The following QC samples are prepared for ICPEAS and GFAAS analysis
• Matrix Spike Sample - one sample per 20 will be spiked with lead prior to
digestion.
• Reagent Blank Sample - One reagent blank will be prepared per group of 20
samples.
• Laboratory Control Sample (LCS) - One LCS sample will be prepared and analyzed
per group of 20 samples.
5.5.2 Analysis Related Quality Control
The following QC samples are analyzed along with routine samples:
5.5.2.1 ICPAES and GFAAS Analyses
Initial Calibration Verification (ICV) Standard - After calibration, the ICV is analyzed.
The percent recovery must be 90-110%. The ICV solution is a standard from a
different source than the calibration standards.
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Initial Calibration Blank (ICB) - After analysis of the ICV, the ICB is analyzed. The
measured concentration must be less than 2 times the EDL.
Interference Check Solution (ICS) - An ICS solution is analyzed after the ICV and
ICB are analyzed. The ICS contains 500 ppm of major interferents (Mg, Ca, Fe, Al)
and a known Pb concentration. The % recovery of Pb must be 75-125%.
Detection Limit Sample (DL) - A DL sample is analyzed after the ICS solution. The
concentration of the DL solution is twice the E)L.
Continuing Calibration Verification Standard (CCV) - A CCV is analyzed every 10
sample and after the last sample. The CCV concentration is in the mid-calibration
range. The % recovery must be 90-110%. If not, the instrument must be recalibrated
and all samples up to the last acceptable CCV must be reanalyzed.
Continuing Calibration Blank Sample (CCB) - A CCB is analyzed after every CCV.
The concentration must be less than twice the IDL.
5.5.2.2 XRF Analyses
Reference Monitor (RM) - Prior to analysis, a reference monitor sample is measured.
The reference monitor intensity provides a standard measure of the x-ray flux that
irradiates the samples being analyzed. The reference monitor provides a method of
standardizing and/or compensating for changes in the x-ray tube flux.
High Initial Calibration Verification Standard (ICVH) - An ICVH sample is analyzed
after the RM and after the last sample in a run. The concentration of Pb is at the high
end of the range of interest
Low Initial Calibration Verification Sample (ICVL) - an ICVL is analyzed after the
ICVH. The concentration of Pb is at low end of the range of interest
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Section 6
Audit Sample Window Generation
6.1 Soil, Dust, and Handwipe Audit Samples
At least 50 aliquots from each soil and dust are analyzed by XRF, wet wipes are analyzed by
ICPES. A biweight statistical procedure is used to calculate audit windows. The biweight
approach has an advantage over the classical approach in that it identifies outliers and weights
them in a manner that gives them less influence on the accuracy window.
After analysis, enter the data into the program, which then generates three estimates of
prediction intervals for single future observation from a univariate normal population (Figure
7.1).
(1) Classical - Based on all data Reference: Whitmore, G.A. "Prediction Limits
for a Univariate Normal Observation", The American Statistician, VOL. 40,
NO. 2, May 1986, PP 141-143.
(2) W/O Outliers - Outliers Removed by Grubbs' Test Reference: Barnett, V.
and Lewis, T. "Outliers in Statistical Data", 2ND ED., John Wiley and Sons,
New York, 1984, P. 167.
(3) Biweight - Robust Estimation Using Biweight Procedure Reference:
Kafadar, K. "A Biweight Approach to the One Sample Problem", Journal of the
American Statistical Association, VOL. 77, NO. 378, PP. 416-424.
PREDICTION
DATA FILE:
TYPE OF
ESTIMATOR
CLASSICAL
W/O OUTLIERS
BIWEIGHT
t OF
DATA
50
SO
50
SAMPLE
MEAN
927.1480
927.1480
923.4212
INTERVAL
SAMPLE
STD DEV
41
41
43
.4193
.4193
.1311
SUMMARY REPORT
95% INTERVAL
LOWER UPPER
843
843
835
.0907
.0907
.8742
1011
1011
1010
.2050
.2050
.9680
99% INTERVAL
LOWER UPPER
814
814
806
.9757
.9757
.5920
1039.3200
1039.3200
1040.2500
Figure 7.1 Example of Audit Sample Prediction Interval Summary Report
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The program also performs the following;
1) Tests for normality using the Kolmogorov-Smirnov and the Anderson-Darling
statistic
2) Presents a histogram of the data
3) Lists the data and the biweight weighting factors
The information is sent to the project QA manager for review before audit samples are sent to
laboratories for inclusion in sample batches.
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Section 7
Safety
7.1 Laboratory Safety
Environmental samples invariably involve undesirable if not hazardous materials and must be
handled with respect. Special equipment and facilities are provided to prevent cross
contamination of space and other samples. Special training in the use of the above may be
needed (Section 1.3.3).
Personnel engaged in handling hazardous samples undergo initial and periodic medical
examinations to insure that they have not contracted medical problems related to the materials
with which they are involved.
7.1.1 Equipment and Supplies
Dust mask
Full face respirator
Laboratory coat
PVC gloves
Tyvek suits
7.1.2 Preparation Laboratory
Dedicated equipment and special facilities are used during sample preparation. The LESC
warehouse has two rooms dedicated to sample drying, sieving, homogenization, riffle
splitting, and sample aliquoting. During each of the above procedures the following
equipment is required: full face respirator, tyvek suit, and PVC gloves.
7.1.3 Characterization Laboratory
The analytical laboratory requires personnel to: 1) work in a laminar hood and wear a dust
mask while splitting samples, 2) wear PVC gloves while handling samples.
B-37
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APPENDIX C - CITY MAPS
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Soil Lead Abatement Demonstration Project
Study Neighborhoods
i. Park Heights
2. Walbrook Junction/Rosemont
1980
CENSUS TRACT MAP
BALTIMORE CITY
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APPENDIX D - ORGANIZATIONAL CHARTS
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Medical Director/
Principal Investigator
Michael Weitzman
Project Director/
Co-
Investigator
Ronald R. Jones
Project
Epidemiologist/
Co-Investigator
Ann Achengrau
Science Director
Co-Investigator
David Bellinger
Research
Assist/Admin.
Dayle Stearns*
Natalie Zaremba
Project
Administrator
Admin. Asst.
Gene Horivtz
Secretary
Norma Byno
Comm
Relations
Director
Sheila
Nutt
r i
Environmental
Coordinator
Bart Hoskins
Deleading
Coordinator
Steve Vega
^
Clerk/ Driver
Roland
Sanefur
Field
Staff
Director
Partricia
Cedeno
\
Assistant
Epidemiologist
Julie Shea
Asst Comm. Relat.
Dir./LL Recruiter
Eva Thorne
Custody Coord
Dayle
Stearns**
\
Data Entry
Clerk
Linda Grant
Clinical Case
Mgr
Case Manager
Clinical Case
Mgr
Case Manager
Clinical Case
Mgr
Case Manager
Clinical Case
Mgr
Case Manager
BOSTON LEAD FREE KIDS STUDY
ORGANIZATIONAL CHART
« 40 % time
**60 % time
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