P. 1

First National Environmental Health Survey

of Child Care Centers

FINAL REPORT

July 15, 2003

Volume I: Analysis of Lead Hazards

Prepared for:

Office of Healthy Homes and Lead Hazard Control

U.S . Department of Housing and Urban Development

451 Seventh Street, SW

Washington, DC 20410

By:

David Marker, Ph.D.

John Rogers, MS

Alexa Fraser, Ph .D.

Susan M. Viet, Ph.D., CIH

Westat, Inc.

1650 Research Boulevard

Rockville, MD 2085 0

This work was conducted under HUD Contract Number C-OPC-21356
p. 2

First National Environmental Health Final Repo rt, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

TABLE OF CONTENT S

ChUter Page

EXECUTIVE SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ES-1

1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1- 1

1 .1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1 .2 Survey Objectives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

1 .3 Report Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

2 SURVEYED CHILD CARE CENTER POPULATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

3 LEAD-BASED PAINT HAZARDS IN CHILD CARE CENTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

3 .1 Definition of Lead-Based Paint Hazards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

3 .2 Prevalence of Significant Lead-Based Paint Hazards in Centers . . . . . . . . . . . . . . . . . . . . . . 3-2

3 .3 Comparison of Significant Lead-Based Paint Hazards Between Child Care

Centers and Homes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6

4 LEAD-BASED PAINT IN CHILD CARE CENTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

4.1 Prevalence of Lead-Based Paint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

4.2 Prevalence of Deteriorated Lead-Based Paint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

4.3 Paint Lead Loadings in Centers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

4.4 Amount of Lead-Based Paint in Centers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10

4.5 Comparison of L-Based Paint Prevalence Between Child Care Centers

and Homes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12

5 DUST LEAD IN CHILD CARE CENTERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5 .1 Prevalence of Dust Lead in Child Care Centers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5.2 Dust Lead Loadings in Child Care Centers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4

5.3 Association between Interior Dust Lead Hazards and Interior and

Exterior Lead-Based Paint Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-11

5 .4 Comparison of Dust Lead Hazard Prevalence Between Child Care Centers

and Homes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12

6 CHILD CARE CENTER SOIL LEAD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

6 .1 Prevalence of Soil Lead . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1

6 .2 Association between Bare Soil Lead and Exte rior Paint Condition . . . . . . . . . . . . . . . . . . 6-5

6 .3 Comparison of Soil Lead Hazard Prevalence Between Child Care Centers

and Homes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6

WESTAT ii July 15, 2003
p. 3

First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

TABLE OF CONTENTS (continued)

Chater Page

7 QUALITATIVE SUMMARY OF SOURCES OF ERROR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

7.1 Statistical Concepts and Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

7.2 Potential for Nonresponse Bias. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

7 .3 Correcting for Classification Bias Due to Measurement Error. . . . . . . . . . . . . . . . . . . . . . . . . . 7-3

7 .4 Quality of Field Data Collection and Analysis fo r

Lead Samples and Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5

7.4.1 Field Data Collection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-5

7.4.2 Laboratory Quality Control Samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6

7 .4.3 Laboratory Selection Quality Assurance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7

7 .4.4 Paint Testing Quality Assurance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7

Table pa

LIST OF TABLES

ge

2-1 National survey estimates of child care centers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

2-2 National survey estimates of children under age 6 in child care centers . . . . . . . . . . . . . . . . . . . . . . . . 2-5

3-1 Prevalence of child care centers with significant LBP hazards, by selected

characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

3-2 Prevalence of significant LBP hazards by location in the child care center . . . . . . . . . . . . . . . . . . . 3-4

3-3 Prevalence of significant LBP hazards in child care centers by type of hazard . . . . . . . . . . . . . 3-5

3-4 Comparison of the prevalence of significant LBP hazards between child care

centers and homes, by type of building characteristic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-7

4-1 Prevalence of LBP by selected child care center characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

4-2 Prevalence of LBP by location in the child care center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

4-3 Prevalence of deteriorated and significantly deteriorated LBP by location in th e

child care center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

4-4 Distribution of centers with deteriorated and significantly dete riorated LBP by

construction year . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5

4-5 Distribution of maximum paint lead loading by location in building (all numbers

represent the percent of all centers) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7

4-6 Distribution of paint lead loading by location in the child care center an d

construction year . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8

4-7 Estimated empirical distribution parameters of paint lead loading by interio r

component types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9

4-8 Estimated empirical distribution parameters of paint lead loading by exterio r

component types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9

4-9 Percentage of rooms/centers with LBP by component type and child care cente r

year of construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-10

4-10a Amount of LBP by painted component . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-11

WESTAT iii July 15, 2003
p. 4

First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

TABLE OF CONTENTS (continued)

LIST OF TABLES ( continued)

Table Pag e

4-10b Percentage of painted area with LBP by painted component . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12

4-10c Average area of LBP in centers with LBP by painted component . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-12

4-11 Comparison of the prevalence of LBP and LBP hazards between child care centers

and homes, by building characteristic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13

5-1 Prevalence of child care centers with a dust lead hazard by characteristics . . . . . . . . . . . . . . . . . . . 5-2

5-2a Distribution of maximum dust lead loadings by surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5

5-2b Distribution of average dust lead loadings by surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6

5-3 Distribution of dust lead loading by room and surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7

5-4 Maximum window sill dust lead loading by year of construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8

5-5 Estimated empiri cal distribution parameters of dust lead loading by surface types . . . . . . . 5-11

5-6 Association between dust lead hazards and presence and condition of interior LBP . . . . . 5-12

6-1 Distribution of soil sample (bare and covered) lead concentrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2

6-2 Distribution of soil sample (bare soil only) lead concentrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3

6-3 Distribution of soil sample (bare and covered) lead concentration s

by construction year. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4

6-4 Distribution of soil sample (bare soil only) lead concentration s

by construction year . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4

6-5 Estimated empirical distribution parameters of soil lead concentrations . . . . . . . . . . . . . . . . . . . . . . . . 6-5

6-6 Association between bare soil lead concentration and presence of

signifi cantly deteriorated exterior LBP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6

7-1 Effect of measurement error on the percentage of centers (hypothetical example ,

assumes 1% misclassification rate). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-4

LIST OF FIGURES

figgLe Page

ES-1 Significant LBP hazards in child care centers by type of hazard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ES-3

3-1 Significant LBP hazards in child care centers by type of hazard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6

4-1 Presence and condition of LBP by construction year . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

5-1 Box plots for dust lead loading by room. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-9

5-2 Box plots for dust lead loading by surface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10

WESTAT iv July 15, 2003
p. 5

First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

EXECUTIVE SUMMARY

The First National Environmental Health Survey of Child Care Centers (referred to here as

the CCC Survey) was conducted under the sponsorship of the Department of Housing and Urban

Development (HUD), the Environmental Protection Agency (EPA), and the Consumer Product Safety

Commission (CPSC) to assess children's potential exposure to lead, allergens, and pesticides in licensed

child care centers that serve children under age 6 in the 48 contiguous United States . Lead levels were

estimated in settled dust, paint, and play area soil ; indoor allergen (allergy-inducing substance) levels

were measured in settled dust; and pesticide residues were determined on indoor surfaces and in play area

soils.

This report, Volume I, includes the findings for lead hazards and describes lead levels in

dust, soil, and paint in the Nation's child care centers by the building's age, type, and geographical

location, and population demographics . In addition, the report estimates the number and percent of child

care centers with dust and soil lead levels above the thresholds in the EPA 403 rule, which HUD adopted

in HUD's Lead Safe Housing Rule (24 CFR Part 35 et al ., Requirements for Notification, Evaluation and

Reduction of Lead-Based Paint Hazards in Federally Owned Residential Property and Housing

Receiving Federal Assistance, effective September 15, 2000) .

Lead-Based Paint Hazards

The number of child care centers classified as having a lead-based paint (LBP) hazard

depends on the definition employed in such classification . This report focuses on significant LBP

hazards, defined in accordance with the HUD Lead Safe Housing Rule (24 CFR 35) . If any of the

following situations exist in a child care center, then a significant LBP hazard exists in the center under

this definition:

■ Deteriorated LBP - LBP with deterioration larger than the de minimis levels per

Section 35.1350(d) of the Lead Safe Housing rule, viz., deterioration of more than 20

square feet (exterior) or 2 square feet (interior) of LBP on large surface area

components (walls, doors) or damage to more than 10 percent of the total surface

area of interior small surface area components types (window sills, baseboards, trim).

LBP is defined as any paint or other surface coating (e .g., varnish, lacquer, or

wallpaper over paint) that contains lead equal to or greater than 1 .0 mg/cmz ; or

WESTAT ES-1 July 15, 2003
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First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

■ Lead-Contaminated Dust - As measured by wipe sampling, dust on floors with

greater than or equal to 40 μg/ftZ lead, dust on window sills with greater than or equal

to 250 μg/ftZ lead ; or

■ Bare, Lead-Contaminated Soil - Any bare soil with a lead concentration greater than

or equal to 400 parts per million (ppm) in a play area .

The findings in the body of this report are based on this definition of a significant LBP

hazard.

An estimated 14,200 or 14 percent' of licensed child care centers in the United States have

significant LBP hazards. Centers in older buildings are more likely to have significant LBP hazards than

those in newer buildings. An estimated 26 percent of centers built before 1960 have significant LBP

hazards, as opposed to around 4 percent of centers in buildings built since 1978 .

These percentages are lower than the incidence of signi fi cant LBP hazards found in houses .

The National Survey of Lead and Allergens in Housing2 found 25 percent of homes had significant LBP

hazards. This percentage increased to 54 percent among homes built before 1960. These estimated

14,200 child care centers, however, imply that 470,000 children attend licensed centers that have

significant LBP hazards .

Centers where the majority of children are African American are four times as likely (30%

compared to 7%) to have significant LBP hazards as those where a majority of the children are white . In

housing this difference was smaller, with 29 percent of African Ame rican homes having significant LBP

hazards and 25 percent of white homes having significant LBP hazards . 3

Figure ES-1 presents graphically the number of centers by type of hazard . The predominant

type of hazard was deteriorated LBP (11%), not dust lead (3%) or soil lead (2%). Eighty percent of

centers with hazards had a paint-lead hazard .

The main chapters of the report include 95 percent confi dence intervals for all estimates . These have been excluded from the Executive

Summa ry.

2 National Surv ey of Lead and Allergens in Housing, Volume I: Analysis of Lead Hazards, Final Repo rt , October 31, 2002, U.S . Depa rtment of

Housing and Urban Development .

In the housing survey, race for a home was de fined as the race of the youngest household member .

WESTAT ES-2 July 15, 2003
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First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

Figure ES-1 . Significant LBP hazards in child care centers by type of hazar d

100,000 child care centers nationally

8E

2,800 centers

with dust lead

= hazard

(3%

11,400 centers with 4100 centers

I ith soil lead significantly

deteriorated LBP hazards

(2%) (11%)

Lead-Based Pain t

An estimated 28,000 or 28 percent of licensed child care centers in the continental United

States have LBP on either the interior or exterior painted surfaces, or both . As expected, centers in older

buildings are more likely to have LBP than newer ones. An estimated 51 percent of centers in buildings

built before 1960 have LBP, while few newer buildings show LBP.

WESTAT ES-3 July 15, 2003
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First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers . Analysis of Lead Hazards

An estimated 15,800 or 16 percent of centers in the United States have deteriorated LBP.

The deteriorated LBP is only on the exterior for more than half of the centers with deteriorated LBP . An

estimated 11,400 or 11 percent of centers in the United States have significantly deteriorated LBP.

Roughly 60 percent of these centers have significant deterioration only on exterior surfaces. The data

suggest that older buildings are more likely to have deteriorated LBP than newer ones . While few newer

buildings have deteriorated LBP, 33 percent of child care centers in buildings built before 1960 have it

.

Twenty-four percent of the older center buildings have significantly deteriorated LBP .

An estimated 11 .8 million square feet of painted interior surfaces are covered with LBP .

This represents 3 percent of the area of painted interior surfaces in all centers. Conversely, 32 percent of

paint on trim contains LBP, but the total surface area of LBP on trim is only 25 percent of the area of LBP

on all interior painted surfaces.

An estimated 18.1 million square feet of painted exterior surfaces are covered with LBP.

This represents 13 percent of the area of painted exterior surfaces in all centers . Wall siding accounts for

most (90%) of the surface area of LBP .

Dust and Soil Lead

An estimated 3 percent of all licensed child care centers have a dust lead hazard somewhere

in the center. An estimated 2 percent of centers have a soil lead hazard, with play area bare soil lead

levels above 400 ppm .

Higher bare soil lead concentrations occur for centers with significantly deteriorated exterior

LBP. Less than 1 percent of centers free of significantly deteriorated exterior LBP have bare soil lead

levels above 400 ppm, while 16 percent of centers with significantly deteriorated exterior LBP have bare

soil lead levels above 400 ppm .

WESTAT ES-4 July 15, 2003
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First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

Survey Design and Methodology

In order to meet the survey objectives, a nationally-representative sample of 334 licensed

child care centers was drawn from 30 clusters called primary sampling units (PSUS).^ A general twostage sample design was utilized to accomplish these goals as efficiently as possible . A total of 168

eligible centers (licensed, with children under 6 years of age, located in the contiguous United States)

were recruited into the survey . In each recruited center, samples of dust and soil were collected and

painted surfaces were tested for lead using licensed inspectors. Unlicensed day care centers were not

included in this survey .

Only classrooms and "multipurpose" rooms (e.g., cafeterias, libraries, ballrooms, and

gymnasiums) where children under 6 years of age regularly spent time were included in the study . All

classrooms were enumerated on one list, while all such multipurpose rooms were enumerated on another.

Up to two classrooms and two multipurpose rooms were then randomly sampled from the lists . A total of

336 rooms were sampled.

Within each room, randomly selected locations on the walls, windows, and other surfaces

were tested for lead through dust wiping and x-ray fluorescence (XRF) testing . A composite soil sample

was collected at up to two sites on the property of each child care center near children's play areas. Each

sample was a composite sample from three locations along the length of the sample site . All samples and

questionnaire data were collected between July and October 2001 .

° A PSU is a metropolitan statistical area (MSA), county, or cluster of counties that has a minimum population of 15,000 and does not cross

Census region boundaries.

WESTAT ES-5 July 15, 2003
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First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

1 . INTRODUCTION

The First National Environmental Health Survey of Child Care Centers (referred to here as

the CCC Survey) was conducted under the sponsorship of the Department of Housing and Urban

Development (HUD), the Environmental Protection Agency (EPA), and the Consumer Product Safety

Commission (CPSC) to assess children's potential exposure to lead, allergens, and pesticides in licensed

child care centers. Lead levels were estimated in dust, paint, and play area soil ; indoor allergen (allergyinducing substance) levels were measured in dust; and pesticide residues were determined on indoor

surfaces and in play area soils. Combining the goals of HUD, EPA, and CPSC into a single survey saved

significant public funds, reduced the survey response burden on the public, and substantially reduced the

time required to obtain the data needed .

This report, Volume I, includes the findings for lead hazards and describes lead levels in

dust, soil, and paint in the Nation's child care centers by age, type, geographical location, and exposed

populations. In addition, the report estimates the number and percent of child care centers with dust and

soil lead levels above the thresholds in EPA's Lead Hazards Standards Rule (40 CFR 765, January 5,

2001) and HUD's Lead Safe Housing Rule (24 CFR Part 35 et al ., Requirements for Notification,

Evaluation and Reduction of Lead-Based Paint Hazards in Federally Owned Residential Property and

Housing Receiving Federal Assistance, effective September 15, 2000) .

1 .1 Background

Lead is a toxin that affects the central nervous system and is particularly damaging to the

developing nervous system of young children and fetuses. High blood lead levels can result in

convulsions, mental retardation, and even death . Research has shown that even low lead levels can have

serious health consequences. These include reduced intelligence and short-term memory, slower reaction

times, poorer hand-eye coordination, reduced height, hearing problems, and numerous behavioral

problems.'

Although there are many sources of lead in the environment, including drinking water, food,

emissions from gasoline combustion, and industrial emissions, it is clear that lead-based paint (LBP)

hazards and the contaminated dust and soil they generate cause most childhood lead poisoning today .

' National Academy of Sciences (1993) . Measuring lead exposure in infants, children, and other sensitive populations. National Academy Press,

Washington, DC.

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Research indicates that dust and soil may be the most significant pathways for lead exposure, and that

LBP is the major important source of household dust lead .'-",'

HUD is implementing a major effort to eliminate childhood lead paint poisoning . HUD has

integrated its program for addressing this health threat into its Healthy Homes Initiative, a program of

research, outreach, and demonstration projects to address housing-related problems related to the health

of children.

CPSC's mandate is to "protect the public against unreasonable risks of injuries and deaths

associated with consumer products." Over the years much of their work has been in child care facilities .

According to CPSC there are 21 million children under age 6 in this country, almost 13 million of whom

are placed in nonparental child care during some portion of the day . CPSC estimates that there are about

100,000 licensed institutional (i.e ., nonhome-based) child care centers in the Nation6 . About 29 percent

of children who receive daycare are in center-based care, including daycare centers, Head Start programs,

and nursery schools. Children often spend as many as 10 or 11 hours per day in centers .

Until now, little was known about lead hazards in daycare centers nationwide . This was

discussed in the report, Eliminating Childhood Lead Poisoning: A Federal Strategy Targeting Lead Paint

Hazards4, produced by the President's Task Force on Environmental Health Risks and Safety Risks to

Children. HUD and CPSC agreed to cooperate on addressing this gap . In furtherance of these activities,

HUD and CPSC are now working collaboratively to understand the extent and condition of LBP on

interior and exterior components, LBP on play equipment, lead in interior dust, and lead in soil in

licensed daycare centers nationwide .

The CCC Survey followed, and in some ways built on the National Survey of Lead and

Allergens in Housing' (NSLAH) . This path-breaking survey determined lead and allergen levels in a

2 Bornschein, R., Hammond, P .B., Dietrich, et al. (1985a). The Cincinnati prospective study of low-level lead exposure and its effects on child

development : Protocol and status report . Environ. Res. 38 :4-18 .

Bomschein, R., Succop, P., Dietrich, et al . (1985b). The influence of social and environmental factors on dust lead, hand lead, and blood lead

levels in young children . Environ. Res. 38 :108-118 .

° President's Task Force on Environmental Health Risks and Safety Risks to Children, ICF Consulting Associates . (2000). Eliminating Childhood

Lead Poisoning: A Federal Strategy Targeting Lead Paint Hazards, Washington DC .

Lanphear, B.P ., Matte, T.D ., Rogers, J., Clickner, R.P ., Dietz, B., et al . (1998). The contribution of lead-contaminated house dust and residential

soil to children's blood lead levels: A pooled analysis of 12 epidemiologic studies . Environmental Research, Section A, 79, 51-68 .

6 CPSC web site (http ://www.cpsc.gov/).

7 National Survey of Lead and Allergens in Housing, Volume ! : Analysis of Lead Hazards, Final Report, October 31, 2002, U .S . Department of

Housing and Urban Development .

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large nationally representative sample of homes, using dust wipes, x-ray fluorescence (XRF) analyzers,

soil collection, and dust vacuuming . All of these methods were retained by the CCC Survey, as were

many of the staff, procedures, and forms used by that earlier study. The CCC Survey focused on licensed

child care centers, rather than the broader range of child care facilities in homes and centers because the

NSLAH had already produced lead and allergen level estimates for homes. It is assumed that child care

provider homes are systematically different from other homes . The two national surveys in homes and

child care centers supplement with each other and provide prevalence estimates of lead hazards in two

major exposure environments for young children .

1 .2 Survey Objectives

One of the Federal Government's principal objectives for the CCC Survey was to develop a

scientific description of the existing lead levels in dust, soil, and paint in the Nation's child care centers .

In addition, the survey of lead hazards in centers collected data to do the following :

■ Estimate the number and percent of centers with dust and soil lead levels above selected thresholds ;

■ Identify likely sources of lead in dust in centers, e .g., paint and soil ;

■ Permit future analyses of lead hazard control strategies and costs (e .g., quantities of deteriorated

painted surfaces); and

■ Permit future analyses for regulation, policy, and guidance that protect children and also minimize

regulatory and program implementation burden.

In order to meet these survey objectives, a nationally-representative sample of 334 child care

centers was drawn from 30 geographic clusters called primary sampling units (PSUs).e A general twostage sample design was utilized to accomplish these goals as efficiently as possible. No national list of

licensed child care centers exists. For each of the 30 sampled PSUs, a list was compiled by contacting the

licensing organization in each state . The sample of 334 child care centers was selected from this list. A

total of 168 eligible centers were recruited into the survey . In each recruited center, samples of dust and

soil were collected and painted surfaces were tested . (See Volume III: Design and Methodology for

details on design and data collection protocols .)

8 A PSU is a metropolitan statistical area (MSA), county, or cluster of counties that has a minimum population of 15,000 and does not cross

Census region boundaries .

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1 .3 Report Organization

The report for the CCC Survey consists of four volumes : Volume I presents the major lead

hazard findings, Volume II presents the major allergen findings, Volume III presents the survey design

and methodology, and Volume IV provides documentation for the survey data files .

There are seven chapters in Volume I, including this introduction . Descriptions of each

chapter are as follows:

■ Chapter 2 describes the population surveyed, both centers and children enrolled in the centers .

■ Chapter 3 presents the estimates of the prevalence of significant lead hazards in centers based

on the findings presented in Chapters 4, 5, and 6 for paint, dust, and soil, respectively. The

types of hazard (paint, dust, and soil) are also presented .

■ Chapter 4 presents the estimates of the prevalence and amount of LBP and deteriorated LBP in

centers, including paint lead loadings .'

■ Chapter 5 presents the estimates of the prevalence of lead-contaminated dust in centers,

including the dust lead loadings and the association between interior dust lead and interior LBP

condition.

■ Chapter 6 presents the estimates of the prevalence of lead-contaminated soil in centers,

including soil lead concentrations and the association between soil lead and exterior LBP

condition.

■ Chapter 7 examines the quality of the data and the resulting quality of projected national

estimates. In order to do this, the chapter addresses nonresponse rates and classification bias

due to measurement error. A summary of field data collection quality control activities is also

provided.

In the subsequent chapters, the precision of the results (shown in parentheses) is reported

using 95 percent confidence intervals. The primary survey results are compared to similar results for

homes from the NSLAH . 1 0

Throughout the volume, the concepts of lead loading and lead concentration are used. Lead in paint and dust is reported as loading, while lead

in soil is reported as a concentration . For paint, lead loading is the number of milligrams of lead per square centimeter of painted surface

(mg/cmZ). For dust, lead loading is the number of micrograms of lead per square foot of wiped surface (μg/ft2) . Soil is reported as the number

of micrograms of lead per gram of soil (pg/g), equivalent to parts per million (ppm).

10 National Survey of Lead and Allergens in Housing, Volume I .• Analysis of Lead Hazards, Final Report, October 31, 2002, U.S. Department of

Housing and Urban Development.

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2. SURVEYED CHILD CARE CENTER POPULATIO N

The First National Environmental Health Survey of Child Care Centers (referred to here as

the CCC Survey) population included all licensed child care centers that serve children under age 6 in the

48 contiguous United States. The surveyed centers were located in buildings in all age categories.

Centers built in 1978 or after were included to determine whether centers in newer buildings have fewer

lead hazards.' Unlicensed child care centers were excluded because it was not possible to get a list from

which to sample. The eligible national population of child care centers consisted of approximately

100,000 licensed centers.

A nationally-representative sample of 334 centers was drawn from 30 clusters called primary

sampling units (PSUs).Z The 30 PSUs were randomly selected from 1,389 PSUs across the continental

United States. Of the 334 sampled centers, 68 were not eligible for the survey . Of the remaining 266

eligible centers, a total of 168 eligible centers were recruited and completed the survey, for a completion

rate of 70 .7 percent.

The sample was to be restricted to licensed child care centers in the 48 contiguous United

States and District of Columbia. While it would be of interest to collect information from all forms of

child care facilities, no lists of non-licensed centers existed from which to select a sample . To survey

non-licensed, home-based centers would require a national sample of homes, whose occupants would

then be asked if they provide child care from their homes . It would be possible to include licensed homebased child care, but information on lead and allergens in homes with children can be obtained from the

recently completed National Survey of Lead and Allergens in Housing . This provides some insight into

the situation in both licensed and non-licensed home-based child care . Thus it was decided to focus the

current survey on larger, generally not home-based child care centers .

Table 2-1 presents the national estimates for selected characteristics of the survey

population, including year of construction, geographic region, degree of urbanization, majority race,

percent of children receiving government subsidies, percent of operating costs from gove rnment

subsidies, whether a Head Start center, center ownership (private or government), and whether centers or

LBP was banned for residential use in 1978 . Because it was not banned for commercial use, it was unknown whether LBP would be present in

newer buildings occupied by child care centers.

2 See Volume III for description of PSUs.

WESTAT 2-1 July 15, 2003
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children have been tested for lead.' All estimates presented are weighted national estimates as discussed

in Volume III. Chapter 7 of this volume discusses the potential effect of nonresponse bias .

Based on the survey data there are an estimated 100,000 licensed child care centers (87,600

to 112,300) 1•5 se rving children under 6 in the continental United States. Of these, 34 percent (28% to

41%) were located in buildings built since 1978, 23 percent (17% to 30%) were built between 1960 and

1977, and 29 percent (25% to 34%) before 1960. The remaining 14 percent did not provide a building

age.' Forty percent of centers in the Northeast and Midwest (31% to 49%) were located in pre-1960

buildings compared to 21 percent (16% to 26%) in the South and West.

About half the centers are located in central cities. In half of the centers most children are

described as white, while in the other half most children are black, Hispanic, or another minori ty. Over

half the centers received government subsides to support at least some of their operating costs, while over

70 percent of centers have some children receiving gove rnment subsidies. Nine percent of centers (5% to

17%) have Head Start programs and 79 percent (69% to 86%) are privately owned . Most centers have

never been tested for lead and do not require blood lead tests for children before enrollment .

Table 2-2 presents the national estimates for number of children in centers with selected

center characteristics. Based on the survey results, there are an estimated 4.62 million children ( 3 .70 to

5 .55 million) under age 6 enrolled in licensed child care centers . The percent of children enrolled by

characte ristics of their child care center is similar to the percent of centers by the same characteristics

( comparing Table 2-1 and Table 2-2) .

Cross comparisons of two variables (e.g ., region by construction year) result in cells containing 30 or fewer centers . Caution is recommended in

the interpretation of results fr om these and other sparse cells .

° 95% confidence intervals for estimates from the survey are shown in parentheses.

Throughout the report tables, the number of centers has been rounded to hundreds of centers, the number of children has been rounded to units

of 10,000 children, and percentages have been rounded to integral percents . Due to rounding, the numbers in the tables may not add up to the

totals for all centers. Even with the rounding, the precision of the numbers (as represented by the confi dence intervals) may not justify all digits

displayed .

6 In the interpretation of the data by year of construction, it is important to keep the source of the data in mind . Center directors were asked the

year their building was constructed . If a director could not report the exact year, he or she was asked to repo rt the construction year in ranges:

1978-2001, 1960-1977, before 1960 or unknown . Many center directors did not know the age of the building . The ages of some buildings

were verified from housing or taxing authoriti es. ( See Volume III for details. )

WESTAT 2-2 July 15, 2003
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First National Environmental Health Final Report, Vol . I

Survey of Child Care Centers Analysis of Lead Hazards

Table 2-1 . National survey estimates of child care centers

Number and Percent of Centers

Centers in

Child Care Center Characteristics Estimate Estimate Lower 95% Upper 95% Sample

(%) CI (%) CI (%)

All Centers 100,000 100 168

Construction Year

1978 to 2001 33,800 34 28 41 57

1960 to 1977 22,900 23 17 30 45

Before 1960 29,200 29 25 34 53

Unknown 14,100 14 13

Region

Northeast/Midwest 45,200 45 39 52 79

South/West 54,800 55 48 61 89

Region by Construction Yea r

Northeast/Midwest

1978 to 2001 12,100 27 19 37 23

1960 to 1977 9,700 22 14 31 19

Before 1960 17,900 40 31 49 31

Unknown 5,400 12 6

South/West

1978 to 2001 21,600 40 30 49 34

1960 to 1977 13,200 24 16 34 26

Before 1960 11,300 21 16 26 22

Unknown 8,700 16 7

Urbanization

MSA Central City 51,200 51 36 66 83

Other MSA 26,600 27 16 40 42

Rural 22,200 22 10 43 43

Majority Race at the Cente r

White 51,300 51 41 62 96

African American 26,800 27 17 40 37

Other 19,200 19 11 30 31

Refusal/Don't Know 2,700 3 4

Percent of Children at the Center

Getting Govt. Subsidy

Greater than 50% 28,900 29 20 39 44

1% to 50% 39,200 39 31 48 73

None 25,800 26 18 36 41

Refusal/Don't Know 6,000 6 10

Percent of Operating Costs from

Govt. Subsidy

Greater than 50% 22,200 22 15 31 36

1% to 50% 26,700 27 20 35 47

None 35,000 35 27 43 62

Refusal/Don't Know 16,000 16 23

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Table 2-1 . National survey estimates of child care centers (continued)

Number and Percent of Centers

Centers in

Child Care Center Characteristics Estimate Estimate Lower 95% Upper 95% Sample

(%) CI (%) CI (%)

Center Has Headstart Progra m

Yes 9,000 9 5 17 14

No 89,400 89 83 94 152

Refusal/Don't Know 1,500 2 2

Center Ownership

Private 78,900 79 69 86 134

Government 19,200 19 12 29 31

Refusal/Don't Know 1,800 2 3

Center Ever Tested for Lead

Yes 19,500 19 14 27 34

No 65,800 66 57 73 111

Refusal/Don't Know 14,600 15 23

Children Required to Have Blood

Test for Lead

Yes 19,400 19 11 32 31

No 73,800 74 60 84 127

Refusal/Don't Know 6,800 7 10

CI = Confidence limit for a 95% confi dence interval for the estimated percent

Values may not add up to the total due to roundin g

MSA = Metropolitan Statistical Area, the "MSA Central City" includes the coun ty in which the MSA central ci ty is located

Percentages (other than region by construction year) use 99,952 centers as the denominator

WESTAT 2-4 July 15, 2003
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First National Environmental Health Final Report, Vol . I

Survey of Child Care Centers Analysis of Lead Hazards

Table 2-2 . National survey estimates of children under age 6 in child care centers

Number and Percent of Children Under 6

Centers in

Child Care Center Characteristics Estimate Estimate Lower 95% Upper 95% Sample

(%) CI (%) Cl(%)

All Centers 4,620,000 100 168

Construction Yea r

1978 to 2001 1,540,000 33 25 42 57

1960 to 1977 820,000 18 12 25 45

Before 1960 1,270,000 27 19 38 53

Unknown 990,000 22 13

Region

Northeast/Midwest 2,210,000 48 37 58 79

South/West 2,410,000 52 42 63 89

Region by Construction Year

Northeast/Midwest

1978 to 2001 420,000 19 10 33 23

1960 to 1977 340,000 16 8 30 19

Before 1960 870,000 39 21 61 31

Unknown 570,000 26 6

South/West

1978 to 2001 1,110,000 46 35 58 34

1960 to 1977 480,000 20 12 30 26

Before 1960 400,000 17 11 24 22

Unknown 420,000 17 7

Urbanization

MSA Central City 2,610,000 56 37 74 83

Other MSA 1,120,000 24 12 44 42

Rural 890,000 19 8 40 43

Majority Race at Cente r

White 2,360,000 51 37 65 96

African American 850,000 18 10 30 37

Other 1,300,000 28 16 45 31

Refusal/Don't Know 110,000 2 4

Percent of Children Getting Govt.

Subsidy

Greater than 50% 1,610,000 35 20 53 44

1% to 50% 1,680,000 36 26 48 73

None 1,130,000 24 14 40 41

Refusal/Don't Know 210,000 5 10

Percent of Operating Costs from

Govt. Subsidy

Greater than 50% 1,340,000 29 15 48 36

1% to 50% 1,000,000 22 14 32 47

None 1,580,000 34 23 48 62

Refusal/Don't Know 690,000 15 23

WESTAT 2-5 July 15, 2003
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Table 2-2 . National survey estimates of children under age 6 in child care centers (continued )

Number and Percent of Children Under 6

Centers in

Child Care Center Characteristics Estimate Estimate Lower 95% Upper 95% Sample

(%) Cl (%) Cl (%)

Center Has Headstart Progra m

Yes 410,000 9 4 17 14

No 4,120,000 89 81 94 152

Refusal/Don't Know 90,000 2 2

Center Ownership

Private 3,750,000 81 69 89 134

Government 780,000 17 10 27 31

Refusal/Don't Know 90,000 2 3.

Center Ever Tested for Lea d

Yes 740,000 16 10 25 34

No 3,180,000 69 59 78 111

Refusal/Don'tKnow 700,000 15 23

Children Required to Have Bloo d

Test for Lea d

Yes 830,000 18 9 32 31

No 3,620,000 78 66 87 127

Refusal/Don't Know 180,000 4 10

Cl = Confidence limit for a 95% confidence interval for the estimated percent

Values may not add up to the total due to rounding

MSA = Metropolitan Statistical Area, the "MSA Central City" includes the county in which the MSA central city is located

Percentages (other than region by construction year) use 4,624,751 children as the denominator

WESTAT 2-6 July 15, 2003
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First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

3 . LEAD-BASED PAINT HAZARDS IN CHILD CARE CENTERS

Chapter 3 presents the estimates of the prevalence of lead-based paint (LBP) hazards in

licensed child care centers, based on the findings presented in Chapters 4, 5, and 6. The types of hazard

(paint, dust, and soil) are also presented .

3.1 Definition of Lead-Based Paint Hazards

The number of child care centers classified as having a LBP hazard depends on the

definition employed in such classification . Under Title X, a LBP hazard is defined as "any condition that

causes exposure to lead from lead-contaminated dust ; bare, lead-contaminated soil ; LBP that is

deteriorated; or LBP present on accessible surfaces, friction surfaces, or impact surfaces" in a child

occupied facility. Several operational definitions have been developed since Title X was enacted . They

involve varying thresholds for lead-contaminated dust and soil and deteriorated LBP . This report focuses

on significant LBP hazards, defined in accordance with the HUD Lead Safe Housing Rule (24 CFR 35) .

If any of the following situations exist in a home or child-occupied facility, then a significant LBP hazard

exists under this definition :

■ Deteriorated LBP - LBP with deterioration larger than the de minimis levels per

Section 35.1350(d) of the EPA and HUD Lead Safe Housing rule, viz ., deterioration

of more than 20 square feet (exterior) or 2 square feet (interior) of LBP on large

surface area components (walls, doors) or damage to more than 10 percent of the

total surface area of interior small surface area components types (window sills,

baseboards, trim).' LBP is defined as any paint or other surface coating (e .g.,

varnish, lacquer, or wallpaper over paint) that contains lead equal to or greater than

1 .0 mg/cmZ ; or

■ Lead-Contaminated Dust - Dust on floors with greater than or equal to 40 μg/ft2lead,

dust on window sills with greater than or equal to 250 μg/ft2 lead as measured by

wipe sampling; or

■ Bare, Lead-Contaminated Soil - Lead content of 400 ppm or more for any amount of

bare soil in a play area frequented by a child under the age of 6 years .

The findings in the body of this report are based on this definition of a significant LBP

hazard.

Intact LBP present on accessible surfaces, friction surfaces, or impact surfaces were not included in the definition of LBP hazard for the

estimates presented in this report because this information was not specifically collected for each component .

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First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

3.2 Prevalence of Significant Lead-Based Paint Hazards in Centers

An estimated 14,200 (7,200 to 21,300)1 or 14 percent (9% to 22%) of licensed child care

centers in the continental United States have significant LBP hazards. Table 3-1 presents the number and

percentage of centers with significant LBP hazards by selected characteristics, including center building

age, region of the country, degree of urbanization, majority race, percent of children receiving a

government subsidy, percent of operating cost from government subsidies, whether it is a Head Start

program, ownership, and whether the center or children are tested for lead .

Centers in older buildings are more likely to have significant LBP hazards then those in

newer buildings. An estimated 26 percent (15% to 42%) of centers built before 1960 have significant

LBP hazards, compared to around 4 percent of centers in newer buildings . Centers where the majority of

children are African American are four times as likely (30% compared to 7%) to have significant LBP

hazards as those where a majority of the children are white.

Another finding, not shown in Table 3-1, is that an estimated 470,000 children under age 6

(170,000 to 760,000) attend licensed child care centers that have significant LBP hazards . This represents

10 percent (4% to 17%) of all children under age 6 who attend licensed child care centers.

Z 95% confidence intervals are shown in parentheses.

WESTAT 3-2 July 15, 2003
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First National Environmental Health Final Report, Vol. I

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Table 3-1 . Prevalence of child care centers with significant LBP hazards, by selected characteristic s

Number of Centers with Significant Percent with

Child Care Center Number of LBP Hazards Significant LBP Hazards Centers in

Characteristics Centers Lower Upper Lower Upper Sample

Estimate 95%

Cl 95% Cl

Estimate 95%

Cl 95% Cl

Total Centers 100,000 14,200 7,200 21,300 14 9 22 168

Construction Yea r

1978 to 2001 33,800 1,500 500 4,400 4 1 13 57

1960 to 1977 22,900 1,300 400 3,900 5 2 17 45

Before 1960 29,200 7,700 3,100 12,300 26 15 42 53

Unknown 14,100 3,900 27 13

Regio n

Northeast/Midwest 45,200 8,500 3,000 14,100 19 10 32 79

South/West 54,800 5,700 1,100 10,300 10 5 22 89

Region by Construction Yea r

Northeast/Midwest

1978 to 2001 12,100 600 100 3,200 5 1 26 23

1960 to 1977 9,700 0 0 2,400 0 0 25 19

Before 1960 17,900 6,600 2,300 11,000 37 20 58 31

Unknown 5,400 1,300 24 6

South/West

1978 to 2001 21,600 900 200 3,300 4 1 15 34

1960 to 1977 13,200 1,300 400 3,700 10 3 28 26

Before 1960 11,300 1,000 200 3,500 9 2 31 22

Unknown 8,700 2,600 29 7

Urbanization

MSA Central City 51,200 9,000 2,600 15,400 18 9 31 83

Other MSA 26,600 2,000 500 7,200 8 2 27 42

Rural 22,200 3,200 500 5,900 14 10 21 43

Majority Rac e

White 51,300 3,400 500 6,200 7 3 14 96

African American 26,800 8,000 1,200 14,700 30 15 50 37

Other 19,200 2,100 400 8,200 11 2 43 31

Refusal/Don't Know 2,700 800 28 4

Percent of Children Getting Govt.

Subsidy

Greater than 50% 28,900 7,000 1,600 12,400 24 13 40 44

1"/0 - 50% 39,200 3,700 1,200 10,000 9 3 25 73

None 25,800 1,200 400 3,500 5 1 14 41

Refusal/Don't Know 6,000 2,300 38 10

Percent of Operating Costs from

Govt. Subsidy

Greater than 50% 22,200 3,200 1,000 8,100 14 5 37 36

1%-50% 26,700 4,100 400 7,900 15 6 34 47

None 35,000 2,500 700 4,400 7 3 14 62

Refusal/Don't Know 16,000 4,400 28 23

Headstart Program

Yes 9,000 2,800 600 6,800 31 6 76 14

No 89,400 9,900 3,800 16,100 11 6 19 152

Refusal/Don't Know 1,500 1,500 100 2

Center Ownershi p

Private 78,900 10,600 4,100 17,100 13 7 23 134

Government 19,200 1,800 400 6,800 9 2 35 31

Refusal/Don't Know 1,800 1,800 100 3

WESTAT 3-3 July 15, 2003
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First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

Table 3-1 . Prevalence of child care centers with significant LBP hazards, by selected characteristics

(continued)

Number of Centers with Significant Percent with

Child Care Center Number of LBP Hazards Significant LBP Hazards Centers in

Characteristics Centers Lower Upper Lower Upper Sample

Estimate 95%

Cl 95% Cl

Estimate

95% Cl 95% Cl

Center Ever Tested for Lead

Yes 19,500 2,800 110,500 625,800 14 6 32 34

No 65,800 6,800 1,400 12,300 10 5 21 111

Refusal/Don't Know 14,600 4,600 31 23

Children Required to Have Blood

Test for Lead

Yes 19,400 4,900 200 9,700 26 12 47 31

No 73,800 6,500 2,100 10,900 9 5 16 127

Refusal/Don't Know 6,800 2,800 41 10

CI = Confidence limit for a 95% confidence interval for the estimated number or percen t

Values may not add to the total due to roundin g

MSA = Metropolitan Statistical Area, the "MSA Central City" includes the county in which the MSA central city is located

Percentages use the number of centers in that row as the denominato r

Table 3-2 presents the number of centers with significant LBP hazards by location in the

building--either interior or exterior, or both . For half the centers with significant LBP hazards, it is only

present on the exterior.

Table 3-2 . Prevalence of significant LBP hazards by location in the child care center

Presence and Number of Centers Percent of Centers (%)

Centers in

Location of Significant LBP Lower Upper Lower Upper Sam le

Hazard Estimate 95% Cl 95% Cl Percent 95% Cl 95% CI p

Present Interior Only 3,100 400 5,900 3 1 7 7

Present Both Interior and

Exterior 4,200 118,000 1,370,200 4 1 14 4

Present Exterior Only 7,000 1,800 12,100 7 3 14 10

Subtotal - Present Anywhere

in Center 14,200 7,200 21,300 14 9 22 21

No Significant LBP Hazard 85,700 73,700 97,700 86 78 91 147

All Centers 100,000 87,600 112,300 100 168

Cl = Confidence limit for a 95% confidence interval for the estimated number or percen t

Values may not add to the total due to rounding

Percentages use 99,952 centers as the denominator

WESTAT 3-4 July 15, 2003
p. 24

First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

Table 3-3 presents data for the presence of significant LBP hazards in centers by type of

hazard. Figure 3-1 graphically displays the same information. Eighty percent (11,400 out of 14,200) of

the centers with a significant lead hazard have paint-related hazards.

Table 3-3. Prevalence of significant LBP hazards in child care centers by type of hazard

Number of Centers Percent of Centers (%)

Type of Hazard Lower Upper Lower Upper Centers in

Estimate Sample 95% Cl 95% ClPercent

95% Cl 95% Cl

Paint 11,400 4,100 18,700 11 6 20 15

Dust 2,800 300 5,400 3 1 7 6

Soil 2,100 700 6,400 2 1 6 3

Any Hazard 14,200 7,200 21,300 14 9 22 21

Cl = Confidence limit for a 95% confidence interval for the estimated number or percent

Values may not add to the total due to rounding

Percentages use 99,952 centers as the denominato r

WESTAT 3-5 July 15, 2003
p. 25

First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

Figure 3-1 . Significant LBP hazards in child care centers by type of hazar d

100,000 child care centers nationally

2,800 centers

with dust lead

hazard

(3%

100 centers 11,400 centers with

ith soil lead significantly

hazards deteriorated LBP

(2%) (11

fC

f

.s®®®®.-®- ® f

3 .3 Comparison of Significant Lead-Based Paint Hazards Between Child Care Centers and

Home s

Table 3-4 shows comparable estimates of the prevalence of significant LBP hazards between

child care centers and homes (based on the National Survey of Lead and Allergens in Housing) . Age,

region, race and urbanization categories were combined to calculate comparable estimates between the

two surveys. In general, almost twice the percent of homes have significant LBP hazards as child care

WESTAT 3-6 July 15, 2003
p. 26

First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

centers. The trends by construction year category and region are similar . One noticeable exception is for

buildings built since 1978 . LBP was outlawed for homes beginning in 1977, but not so for commercial

buildings. Incidence levels for child care centers in rural and MSA areas are similar, unlike for homes. A

greater percentage of child care centers in which most children are African American appear to have

significant LBP hazards than centers in which most children are from other race/ethnicity groups . This

pattern is not seen in the housing survey data .

Table 3-4. Comparison of the prevalence of significant LBP hazards between child care centers and

homes, by type of building characteristi c

Child Care Center/Home Percent(%) with Significant LBP Hazards

Characteristics Child Care Centers Homes

Estimate Lower Upper Estimate Lower Upper

95% Cl 95% CI 95% Cl 95% Cl

All Centers or Homes 14 9 22 25 22 28

Construction Yea r

1978 to 2001 4 1 13 3 1 6

1960 to 1977 5 2 17 8 5 12

Before 1960 26 15 42 54 48 61

Unknown 27 0

Region

Northeast/Midwest 19 10 32 36 31 41

South/West 10 5 22 17 14 20

Urbanization

MSA 14 6 22 23 20 27

Rural 14 10 21 30 20 40

Majority Race

White 7 3 14 25 22 28

African American 30 15 50 29 20 38

Other 11 2 43 23 11 34

Refusal/Don't Know 28 27

WESTAT 3-7 July 15, 2003
p. 27

First National Environmental Health Final Report, Vol . I

Survey of Child Care Centers Analysis of Lead Hazards

4 . LEAD-BASED PAINT IN CHILD CARE CENTER S

Chapter 4 presents estimates of the prevalence, location, and amount of lead-based paint

(LBP) and deteriorated LBP in licensed .child care centers . LBP is defined as any paint or other surface

coating (e.g., varnish, lacquer, or wallpaper over paint) that contains lead equal to or greater than 1 .0

mg/cm2 . The estimates for deteriorated LBP and significantly deteriorated LBP are presented in Section

4.2. LBP is considered to be deteriorated as long as there is any deterioration . It is considered to be

significantly deteriorated if the deterioration exceeds the de minimis thresholds given in the definition of a

significant LBP hazard presented in Chapter 3 .

4 .1 Prevalence of Lead-Based Pain t

An estimated 28,000 (20,100 to 35,900)1 or 28 percent (22% to 35%) of licensed child care

centers in the continental United States have LBP on either the interior or exterior painted surfaces, or

both. Table 4-1 presents the number and percentage of centers with LBP by selected characteristics,

including year of construction, geographic region, degree of urbanization, majority race, percent of

children receiving a government subsidy, percent of operating cost from government subsidies, whether it

is a Head Start program, ownership, and whether the center or children are required to be tested for lead .

As expected, centers in older buildings are more likely to have LBP than newer ones . An

estimated 51 percent (38% to 63%) of centers in buildings built before 1960 have LBP, while only 22

percent (14% to 34%) of buildings built between 1960 and 1977 and 7 percent (3% to 16%) of post-1978

buildings show LBP . The differences among LBP prevalence by region, urbanization, majority race, and

the other table variables do not appear to be significant in that the confidence intervals overlap .

' 95% confidence intervals are shown in parentheses.

WESTAT 4-1 July 15, 2003
p. 28

First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

Table 4-1 . Prevalence of LBP by selected child care center characteristic s

Child Care Center Number of Number of Centers with LBP Percent with LBP Centers in

Characteristics Centers Lower Upper Lower Upper Sample Estimate

95% Cl 95% Cl

Estimate

95% Cl 95% C l

Total Centers 100,000 28,000 20,100 35,900 28 22 35 168

Construction Year

1978 to 2001 33,800 2,500 200 4,700 7 3 16 57

1960 to 1977 22,900 5,000 2,200 7,900 22 14 34 45

Before 1960 29,200 14,900 9,600 20,100 51 38 63 53

Unknown 14,100 5,600 40 13

Region

Northeast/Midwest 45,200 14,900 8,900 20,800 33 24 43 79

South/West 54,800 13,100 7,400 18,800 24 16 34 89

Region by Construction Yea r

Northeast/Midwest

1978 to 2001 12,100 1,200 36,500 341,000 10 3 28 23

1960 to 1977 9,700 2,200 500 3,900 22 12 37 19

Before 1960 17,900 9,300 5,200 13,400 52 36 67 31

Unknown 5,400 2,200 41 6

South/West

1978 to 2001 21,600 1,300 38,500 375,300 6 2 17 34

1960 to 1977 13,200 2,900 600 5,200 22 10 40 26

Before 1960 11,300 5,600 2,300 8,800 49 30 69 22

Unknown 8,700 3,400 39 7

Urbanizatio n

MSA Central City 51,200 16,000 8,600 23,500 31 23 41 83

Other MSA 26,600 8,000 1,600 14,400 30 15 52 42

Rural 22,200 4,000 600 7,300 18 10 29 43

Majority Race

White 51,300 10,500 4,800 16,100 20 12 32 96

African American 26,800 10,700 3,900 17,500 40 24 59 37

Other 19,200 5,600 209,000 1,113,300 29 11 58 31

Refusal/Don't Know 2,700 1,200 45 4

Percent of Children Getting Govt.

Subsidy

Greater than 50% 28,900 8,800 3,200 14,400 31 20 44 44

1%-50% 39,200 9,700 4,000 15,400 25 14 40 73

None 25,800 5,100 2,200 7,900 20 11 32 41

Refusal/Don't Know 6,000 4,400 73 10

Percent of Operating Costs from

Govt. Subsidy

Greater than 50"/u 22,200 5,500 1,400 9,600 25 12 44 36

1%-50% 26,700 7,900 3,700 12,100 29 18 44 47

None 35,000 7,100 3,300 10,900 20 13 31 62

Refusal/Don't Know 16,000 7,500 47 23

Headstart Program

Yes 9,000 3,800 103,300 725,500 42 11 81 14

No 89,400 23,400 16,400 30,400 26 20 33 152

Refusal/Don't Know 1,500 800 50 2

Center Ownership

Private 78,900 23,400 16,600 30,200 30 24 36 134

Government 19,200 3,800 100 7,500 20 7 46 31

Refusal/Don't Know 1,800 800 42 3

WESTAT 4-2 July 15, 2003
p. 29

First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

Table 4-1 . Prevalence of LBP by selected child care center characteristics (continued )

Child Care Center Number of Number of Centers with LBP Percent with LBP Centers in

Characteristics Centers Lower Upper Lower Upper Sample

Estimate 95% CI 95% Cl Estimate 95% CI 95% CI

Center Ever Tested for Lead

Yes 19,500 8,500 3,500 13,500 44 25 64 34

No 65,800 13,400 6,100 20,700 20 12 32 111

Refusal/Don't Know 14,600 6,100 42 23

Children Required to Have Blood

Test for Lea d

Yes 19,400 6,600 2,000 11,200 34 18 54 31

No 73,800 17,200 10,100 24,400 23 17 32 127

Refusal/Don't Know 6,800 4,200 61 10

Cl = Confidence limit for a 95% confidence interval for the estimated number or percent

Values may not add to the total due to roundin g

MSA = Metropolitan Statistical Area, the "MSA Central City" includes the county in which the MSA central city is located

Percentages use number of centers in that row as the denominato r

Table 4-2 presents the number of centers with LBP by location in the building - either

interior or exterior, or both. Almost one-half of centers with LBP have it on both interior and exterior

surfaces (12% of all centers, or 44% (12/28) of centers with LBP anywhere in the building) .

Table 4-2. Prevalence of LBP by location in the child care cente r

Presence and Number of Centers Percent of Centers (%)

Location of LBP Estimate Lower Upper Estimate Lower Upper Centers in

95% Cl 95% Cl 95% CI 95% CI Sample

Present Interior Only 8,200 3,700 12,800 8 5 14 16

Present Both Interior and Exterior 12,300 5,600 19,000 12 7 20 15

Present Exterior Only 7,500 2,800 12,200 7 4 13 13

Subtotal - Present Anywher e

in Center 28,000 20,100 35,900 28 22 35 44

No LBP in Center 72,000 61,600 82,300 72 65 78 124

All Centers 100,000 100 168

CI = Confidence limit for a 95% confidence interval for the estimated number or percen t

Values may not add to the total due to rounding

Percentages use 99,952 centers as the denominator

WESTAT 4-3 July 15, 2003
p. 30

First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

4.2 Prevalence of Deteriorated Lead-Based Paint

Although 28 percent of centers have LBP, the condition of the paint is important in

determining whether a hazard exists. Except during renovations, maintenance, or other activities that

could disturb it, intact LBP is believed to pose little immediate risk to occupants. However, significantly

deteriorated LBP may present an immediate danger to occupants, especially to young children . Table 4-3

presents the number and percentage of child care centers with any deteriorated LBP and significantly

deteriorated (more than the de minimis amounts) LBP by location in the building--either interior or

exterior, or both.

Table 4-3. Prevalence of deteriorated and significantly deteriorated LBP by location in the child care

center

a . Deteriorated LBP

Presence and Location of Deteri

orated Number of Centers Percent of Centers

(%) Centers in

Lead-Based Paint (LBP) Estimate Lower Upper Estimate Lower Upper Sample

95% CI 95% Cl 95% Cl 95% CI

Present Interior Only 2,400 900 6,300 2 1 6 5

Present Both Interior and Exterior 4,700 0 9,400 5 2 12 5

Present Exterior Only 8,700 2,900 14,500 9 5 16 13

Subtotal - Present Anywhere

in Center 15,800 8,000 23,500 16 10 24 23

No Deteriorated LBP 84,200 72,300 96,100 84 76 90 145

All Centers 100,000 100 168

b . Significantly Deteriorated LBP

Presence and Location of Significantly Number of Centers Percent ofCenters (%)

Centers in

Deteriorated Lead-Based Paint (LBP) Estimate Lower Upper Estimate Lower Upper Sample

95% Cl 95% CI 95% CI 95% Cl

Present Interior Only 1,400 400 5,500 1 0 5 3

Present Both Interior and Exterior 3,400 1,100 10,300 3 1 10 3

Present Exterior Only 6,600 1,400 11,900 7 3 14 9

Subtotal - Present Anywhere

in Center 11,400 4,100 18,700 11 6 20 15

No Significantly Deteriorated LBP 88,500 76,500 100,600 89 80 94 153

All Centers 100,000 100 168

Cl = Confidence limit for a 95% confidence interval for the estimated number or percent

Values may not add to the total due to rounding

Percentages use 99,952 centers as the denominato r

An estimated 15,800 (8,000 to 23,500) or 16 percent (10% to 24%) of child care centers in

the United States have some deteriorated LBP . The deteriorated LBP is on the exterior for over half of

WESTAT 4-4 July 15, 2003
p. 31

First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

the centers with deteriorated LBP. An estimated 11,400 (4,100 to 18,700) or 11 percent (6% to 20%) of

centers in the United States have significantly deteriorated LBP . Roughly 60 percent of these centers

have significant deterioration on exterior surfaces only .

Table 4-4 presents the number and percentage of centers with deteriorated and significantly

deteriorated LBP by construction year . The data suggest that older buildings are more likely to have

deteriorated LBP than newer ones . One percent of post-1978 buildings have deteriorated LBP and four

percent of centers build between 1960 and 1977 have deteriorated LBP. In contrast, 33 percent (20% to

48%) of centers built before 1960 have it. Of centers built before 1960, 24 percent (13% to 40%) have

significantly deteriorated LBP .

Table 4-4. Distribution of centers with deteriorated and significantly deteriorated LBP by construction

year

a. Deteriorated LBP

Number of Centers with Deteriorated Percent with

Construction Year Number of LBP Deteriorated LBP (%) Centers in

Centers Lower Upper Lower Upper Sample Estimate 95% Cl 95% Cl Estimate 95% Cl 95% Cl

1978 to 2001 33,800 400 100 2,600 1 0 8 57

1960 to 1977 22,900 1,000 200 3,500 4 1 15 45

Before 1960 29,200 9,600 4,500 14,700 33 20 48 53

Unknown 14,100 4,800 34 13

Total Centers 100,000 15,800 8,000 23,500 16 10 24 168

b . Significantly Deteriorated LB P

Number of Centers with Significantl y

Deteriorated Percent with Significantly

Construction Year Number of Deteriorated LBP (%) Centers in

Centers Lower Upper Lower Upper Sample

LBP

Estimate 95% Cl 95% Cl Estimate 95% Cl 95% Cl

1978 to 2001 33,800 0 0 3,400 0 0 10 57

1960 to 1977 22,900 500 100 2,900 2 0 13 45

Before 1960 29,200 7,100 2,600 11,600 24 13 40 53

Unknown 14,100 3,900 27 13

Total Centers 100,000 11,400 4,100 18,700 11 6 20 168

CI = Confidence limit for a 95% confidence interval for the estimated number or percen t

Values may not add to the total due to roundin g

Percentages use number of centers in that row as the denominato r

Figure 4-1 is a bar chart that summarizes the above survey data on deteriorated and

significantly deteriorated LBP by construction year . It graphically displays the downward trend in the

prevalence of LBP and of damaged LBP in centers, as year of construction increases .

WESTAT 4-5 July 15, 2003
p. 32

First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

Figure 4-1 . Presence and condition of LBP by construction yea r

60,000

❑ No LBP

50,000 ❑ Undamaged LBP

y De minimis deterioration

4) ■ Significant deterioration

a w 40,000

a~ d L 'a

V 3

~ 30,000

~ L

V V

C

L V I

L

~ = 20,000

7

Z

10,000 _

Unknown Before 1960 1960 to 1977 1978 to 2001

Building construction yea r

4.3 Paint Lead Loadings in Centers

Table 4-5 presents the distribution of the highest lead paint loading in each center by

location in the building for selected thresholds: 0.3, 0.6, 0.7, 0.8, 1 .0, 1 .3, 4.0, and 10.0 mg/cm2 . By

statutory definition, paint with less than 1 .0 mg/cmZ is not LBP; thus, the first four categories include

paint that is considered not to be LBP. The majority of the surfaces tested did not contain LBP . An

estimated 28 percent of centers had at least one component painted with LBP . Nine percent of centers

had at least one paint measurement with lead loading of 10 mg/cmZ or more.

WESTAT 4-6 July 15, 2003
p. 33

First National Environmental Health Final Repo rt, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

Table 4-5 . Distribution of maximum paint lead loading by location in the building (all number s

represent the percent of all centers )

Maximum Paint Lead Interior Exterior Anywhere

Loading in Center Lower Upper Lower Upper Lower Upper Estimate

95% Cl 95% CI

Estimate

95% CI 95% CI Estimate 95% CI 95% CI

No Paint ('

) 12 8 18

GT 0 mg/cmZ 100 86 78 91 100

GE 0 .3 mg/cm2 47 39 56 30 23 38 54 45 62

GE 0 .6 mg/cm2 30 23 38 23 16 31 37 30 45

GE 0 .7 mg/cm2 27 20 35 22 16 30 34 27 42

GE 0 .8 mg/cmz 24 17 31 22 16 30 31 25 38

GE 1 .0 mg/cm2 21 15 27 20 14 28 28 22 35

GE 1 .3 mg/cmz 15 10 22 15 10 22 23 17 29

GE 4 .0 mg/cm2 10 6 18 10 6 16 15 10 21

GE 10.0 mg/cmZ 6 3 13 7 3 13 9 5 15

"° One center had exterior paint but no XRF measurement ; 24 centers had no exterior paint

Cl = Confi dence limit for a 95% confidence interval for the estimated number or percent

GT = Greater tha n

GE = Greater than or equal t o

Values may not add up to the total due to rounding

Percentages use 99,952 centers as the denominator

Table 4-6 presents the distribution of paint lead loadings by location in the building and

construction year for the selected thresholds. This clearly demonstrates the effectiveness of the reduction

from 1940 to 1980 in the amount of lead added to commercial residential paint . An estimated 15 percent

of centers in buildings reported as built before 1960 had at least one lead measurement somewhere in the

center at 1 .0 mg/cmZ, or above. This decreased to 5 percent of centers reported as built between 1960 and

1977, and to 2 percent of centers repo rted as built since 1978. The same patte rn holds for ve ry high lead

levels, with 7 percent of pre-1960 centers having some lead above 10 mg/cmZ but none for post-1960

centers.

WESTAT 4-7 July 15, 2003
p. 34

First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

Table 4-6. Distribution of paint lead loading by location in the child care center and construction year

Percent of Child Care Centers with LBP

Highest Paint Lead Year of Construction

Loading in the Child All Centers

Care Center 1978 to 2001 1960 to 1977 Before 1960 Unknow n

Interior

GE 0 mg/cm 34 23 29 14 100

GE 0.3 mg/cmZ 8 11 20 9 47

GE 0.6 mg/cmz 4 7 14 6 30

GE 0.7 mg/cmZ 3 6 13 5 27

GE 0.8 mg/cmZ 2 4 13 5 24

GE 1 .0 mg/cm2 1 3 12 5 21

GE 1 .3 mg/cm2 0 2 10 3 15

GE 4.0 mg/cmz 0 1 7 3 10

GE 10.0 mg/cmZ 0 0 5 1 6

Exterior

No Exterior Paint 5 2 4 1 12

GE 0 mg/cm2 29 21 23 13 86

GE 0.3 mg/cm2 5 7 13 6 30

GE 0.6 mg/cmz 2 5 10 6 23

GE 0.7 mg/cmZ 2 4 10 6 22

GE 0.8 mg/cmZ 2 4 10 6 22

GE 1 .0 mg/cmZ 2 3 9 6 20

GE 1 .3 mg/cm2 1 1 9 4 15

GE 4.0 mg/cm2 0 0 6 4 10

GE 10.0 mg/cmZ 0 0 5 2 7

Anywhere in Building

GE 0 mg/cm 34 23 29 14 100

GE 0.3 mg/cm2

9 12 22 10 54

GE 0.6 mg/cmZ 6 9 16 7 37

GE 0.7 mg/cmZ 5 8 15 6 34

GE 0.8 mg/cm2 4 6 15 6 31

GE 1 .0 mg/cmZ 2 5 15 6 28

GE 1 .3 mg/cmZ 1 3 14 4 23

GE 4.0 mg/cm2 0 1 10 4 15

GE 10.0 mg/cmZ 0 0 7 2 9

(1) One center had exterior paint but no XRF measurement ; 24 centers had no exterior paint

(2) Negative XRF readings were assumed to be zero for this table .

GE= Greater than or equal to

Values may not add up to the total due to rounding

Percentages use 99,952 centers as the denominator

WESTAT 4-8 July 15, 2003
p. 35

First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

Tables 4-7 and 4-8 present selected parameters of the distributions of paint lead loadings for

interior and exterior component types. All of the distributions in the tables are right-skewed with many

zero values and thus cannot be reasonably fitted by normal or log-normal distributions .

Table 4-7 . Estimated empirical distribution parameters of paint lead loading by interior component

types

Walls and Windows Doors Trim Toys/Play Other Floors Equipment

mg/cm2 mg/cm2 mg/cmZ mg/cm2 mg/cm2 mg/cmZ

Arithmetic Mean 0.12 0.78 0.12 0.42 0.02 0.17

Arithmetic Standard Deviation 1 .17 3.90 1.46 2.16 0.09 1.05

25th Percentile 0 0 0 0 0 0

Median 0 0 0 0 0 0

75th Percentile 0 0 0 0 0 0

90th Percentile 0.1 0.4 0.1 0.2 0.1 0.2

95th Percentile 0.3 3 0.2 1.3 0.1 0.5

Maximum 31 44 32 20 0.9 11

Number of Readings 2407 442 856 257 213 228

The geometric mean and standard deviation were not calculated due to the large number of zero readings .

Table 4-8 . Estimated empirical distribution parameters of paint lead loading by exterior component

types

Walls Windows Doors Trim Porch Play Other

Equipment

mg/cm 2 mg/cm2 mg/cm2 mg/cmZ mg/cm2 mg/cm2 mg/cmZ

Arithmetic Mean 0.96 1.93 1.07 0.37 0.12 0.06 4.23

Arithmetic Standard Deviation 5.03 6.14 4.77 2.10 0.49 0.32 14.95

25th Percentile 0 0 0 0 0 0 0

Median 0 0 0 0 0 0 0

75th Percentile 0 0.1 0.1 0 0 0 0

90th Percentile 0.2 3.2 0.9 0.1 0.1 0.1 5.7

95th Percentile 2.5 21 3.7 0.2 1.1 0.3 58

Maximum 34 28 42 14 3.1 3.4 58

Number of Readings 164 85 187 46 66 172 15

The geometric mean and standard deviation were not calculated due to the large number of zero readings .

Table 4-9 summarizes the data in Tables 4-7 and 4-8 by presenting the percentage of rooms

with components with LBP by component type and center age . It also shows the expected trends and

differences with older buildings having more LBP than newer ones .

WESTAT 4-9 July 15, 2003
p. 36

First National Environmental Health Final Report, Vol . I

Survey of Child Care Centers Analysis of Lead Hazards

Table 4-9 . Percentage of rooms/centers with LBP by component type and child care center year of

construction

Component Type Year of Construction

1978 to 2001 1960 to 1977 Before 1960 Unknown All Centers

Interior Walls or Floors 0 6 9 11 5

Windows 0 2 13 14 7

Doors 0 1 7 4 3

Trim 0 3 8 18 5

Other 2 2 5 6 3

All Interior Components 1 8 24 20 12

Exterior Walls 2 0 8 8 4

Windows 0 2 11 8 5

Doors 2 7 15 23 9

Trim 0 0 4 0 1

Porch 0 0 8 0 2

Play Equipment 2 2 2 0 2

Other 0 0 0 100 15

All Exterior Components 5 11 28 38 17

For interior components, percentages use the number of rooms as the denominator . For exterior components, percentages use the

number of centers as the denominator.

4 .4 Amount of Lead-Based Paint in Centers

Table 4-10 presents estimates of the area of LBP by architectural component type . The first

portion of the table shows the square feet of LBP ; the second portion shows the area of LBP as percent of

the area of all painted surfaces, and the third portion presents the average area of LBP for those centers

with any LBP. An estimated 11 .8 million square feet of painted interior surfaces are covered with LBP .

This represents only 3 percent of the area of painted interior surfaces in all centers . Although 3 percent of

paint on walls, floors, and ceilings is LBP, the area of these LBP-coated components accounts for 62

percent (7.27/11 .78) of all interior surfaces with LBP. Conversely, 32 percent of paint on trim contains

LBP, but the total surface area of LBP on trim is only 25 percent of the area of all interior painted

surfaces.

An estimated 18 .1 million square feet of painted exterior surfaces are covered with LBP .

This represents 13 percent of the area of painted exterior surfaces in all centers. Exterior walls account

for 90 percent (16 .26/18.07) of the exterior surface area of LBP .

WESTAT 4-10 July 15, 2003
p. 37

First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

Of those centers with LBP, most have relatively small areas of LBP . The average center

with LBP has 421 square feet of interior LBP and 645 square feet of exterior LBP . 2

Table 4-10a. Amount of LBP by painted component

Component Millions of Square Feet of LBP

1978 to 2001 1960 to 1977 Before 1960 Unknown All Centers

Interior Wall, Floor, Ceiling 0.00 3.15 1.75 2.37 7.27

Window 0.00 0.01 0.14 0.27 0.42

Door 0.00 0.01 0.15 0.16 0.32

Trim 0.00 0.01 0.20 2.79 3.00

Other 0.02 0.01 0.62 0.10 0.75

TOTAL 0.02 3.19 2.87 5.70 11.7 8

Exterior Wall 1.83 0.00 13.78 0.65 16.26

Window 0.00 0.00 0.54 0.10 0.65

Door 0.00 0.02 0.07 0.06 0.15

Trim 0.00 0.00 0.12 0.00 0.12

Porch 0.00 0.00 0.67 0.00 0.67

Play Equipment 0.11 0.00 0.00 0.00 0.11

Other 0.00 0.00 0.00 0.11 0.11

TOTAL 1.95 0.03 15.18 0.92 18.07

Values may not add up to the total due to rounding

2 For comparison, a room 10'x 12' with an 8' ceiling has a wall area of 352 square feet and a combined wall, ceiling, and floor area of 592 square

feet.

WESTAT 4-11 July 15, 2003
p. 38

First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

Table 4-10b. Percentage of painted area with LBP by painted componen t

Area of LBP as Percent of All Paint on the Component

Component

1978 to 2001 1960 to 1977 Before 1960 Unknown All Centers

Interior Wall, Floor, Ceiling 0 5 2 4 3

Window 0 1 5 25 6

Door 0 0 2 4 1

Trim 0 1 8 71 32

Other 1 0 8 2 4

TOTAL 0 4 3 7 3

Exterior Wall 5 0 39 14 14

Window 0 1 35 92 20

Door 1 5 13 22 9

Trim 0 0 17 0 4

Porch 0 0 14 0 5

Play Equipment 34 0 0 0 15

Other 0 0 0 100 18

TOTAL 4 0 35 16 13

Percentages use the area of paint in the cell as the denominator

Table 4-10c. Average area of LBP in centers with LBP by painted component

Average Amount LBP per Center with LBP (square feet) Component

1978 to 2001 1960 to 1977 Before 1960 Unknown All Centers

Interior Wall, Floor, Ceiling 0 626 118 421 260

Window 0 2 10 48 15

Door 0 3 10 29 11

Trim 0 2 14 495 107

Other 8 2 42 18 27

TOTAL 8 635 193 1011 421

Exterior Wall 744 0 927 115 581

Window 0 1 36 18 23

Door 1 5 5 10 5

Trim 0 0 8 0 4

Porch 0 0 45 0 24

Play Equipment 45 0 0 0 4

Other 0 0 0 19 4

TOTAL 790 5 1021 163 645

Values may not add to the total due to rounding

4.5 Comparison of Lead-Based Paint Prevalence Between Child Care Centers and Homes

Table 4-11 shows comparable estimates of the prevalence of LBP and deteriorated LBP

between child care centers and homes (based on the National Survey of Lead and Allergens in Housing) .

WESTAT 4-12 July 15, 2003
p. 39

First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

Age, region, and urbanization categories were combined to calculate comparable estimates between the

two surveys. In general, a higher percent of homes have LBP than child care centers . Forty percent of

homes have LBP while only 28 percent of child care centers have LBP . The trends by construction year

category and region are similar . However, for buildings built since 1960, a higher proportion of child

care centers have LBP than homes. This is likely due to the reductions in lead levels required for

residential paint. The relative differences between MSA/non-MSA areas are different for the two

surveys. A greater percentage of child care centers have LBP in MSAs compared to rural areas . A

slightly higher proportion of homes have deteriorated LBP and significantly deteriorated LBP (18% and

14% respectively) than child care centers (16% and 11% respectively) .

Table 4-11 . Comparison of the prevalence of LBP and LBP hazards between child care centers and

homes, by building characteristic

Percent with LBP

Child Care Center/Home Child Care Centers Homes

Characteristics Lower Upper Lower Upper

Estimate 95% Cl 95% Cl Estimate 95% Cl 95% Cl

All Centers or Homes 28 22 35 40 36 43

Construction Yea r

1978 - 2001 7 3 16 7 2 12

1960-1977 22 14 34 24 18 30

Before 1960 51 38 63 77 72 82

Unknown 40

Region

Northeast/Midwest 33 24 43 54 49 59

South/West 24 16 34 29 25 33

Urbanization

MSA 30 23 39 47 35 59

Rural 18 10 29 37 33 41

Majority Rac e

White 20 12 32 40 37 44

African American 40 24 59 41 30 52

Other 29 11 58 29 17 41

Refusal/Don't Know 45

Percent with Deteriorated LB P

All Centers or Homes 16 10 24 18 16 20

Percent with Si ificantl Dete riorated LBP

All Centers or Homes 11 6 20 14 12 17

WESTAT 4-13 July 15, 2003
p. 40

First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

5 . DUST LEAD IN CHILD CARE CENTER S

Chapter 5 presents estimates of the prevalence of lead-contaminated dust in licensed child

care centers (CCCs), including the dust lead loadings and the association between interior dust lead and

interior lead-based paint (LBP) condition.

5.1 Prevalence of Dust Lead in Child Care Centers

Table 5-1 presents the prevalence of centers with a dust lead hazard somewhere in the

center.' A dust lead hazard is defined as greater than or equal to 40 11 g/fft2 lead on floors or 250 μg/ftz lead

on interior window sills. An estimated 3 percent (1% to 7%)Z of all licensed CCCs in the continental

United States have a dust lead hazard somewhere in the center. However, due to the small number of

centers with a dust lead hazard, it is not possible to fu rther characterize the centers with dust lead hazards .

The maximum lead dust loading on any surface tested (separately for floor and window sill) in the center was used to determine whether a dust

lead hazard existed .

2

95% confidence inte rvals are shown in pare ntheses.

WESTAT 5-1 July 15, 2003
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First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

Table 5-1 . Prevalence of child care centers with a dust lead hazard by characteristic s

Number of Centers with a Dust

Percent of Centers

Child Care Center Characteristics Number of Lead Hazard Centers in

Centers Lower Upper 95% Lower Upper Sample

Estimate 95%

Cl

CI Estimate 95%

Cl 95% Cl

Total Centers 100,000 2,800 300 5,400 3 1 7 168

Construction Yea r

1978 to 2001 33,800 1,200 300 4,200 3 1 12 57

1960 to 1977 22,900 800 100 4,100 3 1 18 45

Before 1960 29,200 900 200 3,700 3 1 13 53

Unknown 14,100 0 0 13

Regio n

Northeast/Midwest 45,200 1,500 500 4,400 3 1 10 79

South/West 54,800 1,300 300 4,900 2 1 9 89

Region by Construction Year

Northeast/Midwest

1978 to 2001 12,100 600 100 3,200 5 1 26 23

1960 to 1977 9,700 0 0 2,400 0 0 25 19

Before 1960 17,900 900 200 3,600 5 1 20 31

Unknown 5,400 0 0 6

South/West

1978 to 2001 21,600 600 100 3,100 3 0 14 34

1960 to 1977 13,200 800 100 3,800 6 1 29 26

Before 1960 11,300 0 0 2,500 0 0 22 22

Unknown 8,700 0 0 7

Urbanization

MSA Central City 51,200 1,500 500 4,300 3 1 8 83

Other MSA 26,600 0 0 3,500 0 0 13 42

Rural 22,200 1,400 400 4,400 6 2 20 43

Majority Rac e

White 51,300 1,500 500 4,200 3 1 8 96

African American 26,800 600 100 3,400 2 0 13 37

Other 19,200 0 0 3,300 0 0 17 31

Refusal/Don't Know 2,700 800 28 4

WESTAT 5-2 July 15, 2003
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First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

Table 5-1 . Prevalence of child care centers with a dust lead hazard by characteristics (continued)

Number of Centers with a Dust

Percent of Centers

Child Care Center Characteristics Number of Lead Hazard Centers in

Centers Lower Upper 95% Lower Upper Sample

Estimate

95% Cl Cl

Estimate 95%

Cl 95% C l

Percent of Children Getting Govt .

Subsid y

Greater than 50"/0 28,900 900 200 3,500 3 1 12 44

1°/u - 50% 39,200 0 0 3,100 0 0 8 73

None 25,800 1,200 400 3,500 5 1 14 41

Refusal/Don't Know 6,000 800 13 10

Percent of Operating Costs fro m

Govt. Subsid y

Greater than 50% 22,200 300 0 1,900 1 0 8 36

1%-50% 26,700 600 100 3,200 2 0 12 47

None 35,000 1,200 400 3,600 3 1 10 62

Refusal/Don't Know 16,000 800 5 23

Headstart Progra m

Yes 9,000 0 0 2,800 0 0 31 14

No 89,400 2,100 0 4,100 2 1 6 152

Refusal/Don't Know 1,500 800 50 2

Center Ownershi p

Private 78,900 2,100 0 4,100 3 1 7 134

Government 19,200 0 0 3,300 0 0 17 31

Refusal/Don't Know 1,800 800 41 3

Center Ever Tested for Lead

Yes 19,500 300 0 1,800 2 0 9 34

No 65,800 1,800 600 5,100 3 1 8 111

Refusal/Don'tKnow 14,600 800 5 23

Children Required to Have Bloo d

Test for Lead

Yes 19,400 0 0 3,300 0 0 17 31

No 73,800 2,100 0 4,100 3 1 7 127

Refusal/Don't Know 6,800 800 11 10

CI = Confidence limit for a 95% confidence interval for the estimated number or percent

Values may not add to the total due to roundin g

MSA = Metropolitan Statistical Area, the "MSA Central City" includes the county in which the MSA central city is located

Percentages use the number of centers (left end of the row) as the denominato r

WESTAT 5-3 July 15, 2003
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First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

5.2 Dust Lead Loadings in Child Care Centers

Tables 5-2a and 5-2b present information on maximum and average dust loadings,

respectively, by surface . Table 5-2a presents the distribution of maximum dust lead loadings by surface

(floor and window sill) for all centers in the target population, for selected threshold values . In most of

the centers the maximum floor dust lead loading is below the limit of detection3 . In almost all centers the

maximum floor dust lead loading is also less than the reporting limit .4 None of the centers have

maximum floor dust lead loadings above the standard of 40 μg/ft . An estimated 25 percent of all centers

have sill dust lead loadings above the reporting limit, but only 3 percent are above the standard of 250

μg/ft2 . The low numbers of centers with lead dust hazard may be due to the frequent (at least daily)

cleaning that licensed CCCs are required to or often conduct .

Table 5-2b presents the distribution of average dust lead loadings by surface (floor and

window sill) for all centers in the target population . The average dust loading for each center was

determined by simply adding the dust loadings for each room sampled in each center and dividing by the

number of rooms sampled (unweighted average). '

The same trends are observed in Table 5-2b for average dust lead loadings as for the

distribution of maximum dust lead loadings in Table 5-2a . Only 1 percent of centers have average

window sill loadings above 250 μg/ft .

3 The average analytical detection limit for each wipe sample was 3 .5 μg. While detection limits for each surface are area dependent, this

corresponds to a detection limit of 3 .5 μg/ftz for a one square foot floor sample or 7 μg/ftZ for a typical 3" x 24" sill sample .

° The lowest lead value a lab can confidently report for the wipe samples . The reporting limit was 10 μg . While reporting limits for each surface

are area dependent, this corresponds to a reporting limit of 10 μg/ftz for a I square foot floor sample or 20 μg/ft for a typical 3" x 24" sill

sample.

For averaging floor samples, only carpeted floor samples and uncarpeted floor samples were combined for the respective average (carpeted or

uncarpeted) .

WESTAT 5-4 July 15, 2003
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First National Environmental Health Final Repo rt, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

Table 5-2a. Distribution of maximum dust lead loading by surfac e

Maximum Dust Lead Loading in Number of Centers Percent of Centers (%)

Child Care Cente r

(flg/sq ft) Estimate Lower Upper 95% Estimate Lower Upper

95% Cl CI 95%Cl 95% CI

Floors

LT LOD 73,700 62,400 84,900 74 64 82

GE LOD 26,300 16,200 36,400 26 18 36

GE Reporting limit 1,100 300 4,200 1 0 4

GE 20 600 100 3,700 1 0 4

GE 40 0 0 3,600 0 0 4

GE 100 0 0 3,600 0 0 4

Window Sills

LT LOD 30,200 22,500 38,000 30 23 38

GE LOD 55,300 44,100 66,500 55 48 62

GE Reporting limit 24,800 16,100 33,600 25 18 34

GE 125 4,700 900 8,600 5 2 10

GE 250 2,800 300 5,400 3 1 7

GE 500 600 100 3,600 1 0 4

No sill present in Sampled Rooms 10,700 6,000 15,500 11 7 16

Missing/Inaccessible 3,600 4 1 9

Values may not add to the total due to rounding

Percentages use 99,952 centers as the denominator

LT LOD = Less than the limit of detection

GE LOD = Greater than or equal to the limit of detection

Reporting limit = The lowest lead value a lab can confidently repo rt for the wipe samples . The reporting limit was 10 μg . While

reporting limits for each surface are area dependent, this corresponds to a repo rting limit of 10 μg/ftz for a 1 square foot floor

sample or 20 μg/ft2 for a typical 3" x 24" sill sample .

WESTAT 5-5 July 15, 2003
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First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

Table 5-2b. Distribution of average dust lead loading by surfac e

Average Dust Lead Loading in Number of Centers Percent of

Centers (%)

Child Care Center Lower Upper Lower Upper

(~g/sq ft) Estimate 95% Cl 95% Cl

Estimate

95% Cl 95% Cl

Floors (Uncarpeted)

LT LOD 54,600 44,600 64,600 55 47 62

GE LOD 14,200 8,800 19,700 14 10 20

GE Repo rting limit 600 100 3,700 1 0 4

GE 20 600 100 3,700 1 0 4

GE 40 0 0 3,600 0 0 4

GE 100 0 0 3,600 0 0 4

No uncarpeted floors present 31,100 24,700 37,500 31 25 38

Floors (Carpeted )

LT LOD 43,100 33,600 52,500 43 36 51

GE LOD 7,500 3,200 11,800 8 4 13

GE Repo rting limit 0 0 3,600 0 0 4

GE 20 0 0 3,600 0 0 4

GE 40 0 0 3,600 0 0 4

GE 100 0 0 3,600 0 0 4

No carpeted floors present 49,400 40,300 58,400 49 42 56

Window Sills

LT LOD 35,800 27,800 43,800 36 29 43

GE LOD 49,800 40,100 59,400 50 44 56

GE Repo rting limit 18,400 10,800 26,000 18 12 27

GE 125 3,400 700 6,000 3 2 7

GE 250 1,200 300 4,200 1 0 4

GE 500 600 100 3,600 1 0 4

No sill present in Center 10,700 6,000 15,500 11 7 16

Missing 3,600 4

Cl = Confidence limit for a 95% confidence interval for the estimated number or percent

Percentages use 99,952 centers as the denominator

LT LOD = Less than the limit of detection

GE LOD = Greater than or equal to the limit of detectio n

Repo rt ing limit = The lowest lead value a lab can confidently report for the wipe samples. The reporting limit was 10 μg . While

reporting limits for each surface are area dependent, this corresponds to a reporting limit of 10 μg/ftZ for a 1 square foot floor

sample or 20 μg/ftz for a typical 3" x 24" sill sample .

Table 5-3 presents the distribution of dust lead loadings by room type and surface for

selected threshold values. The vast majori ty of floors had undetectable levels of dust lead. None of the

classrooms and only 3 percent of multipurpose rooms had floor dust lead levels above 20 μg/ft2 . One

WESTAT 5-6 July 15, 2003
p. 46

First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

percent of classrooms and 2 percent of multipurpose rooms had window sill dust lead levels above the

standard for window sills.

Table 5-4 presents the maximum window sill dust lead loading, by selected thresholds and

by year of construction. Note that while many more centers built before 1960 have window sill dust

above reporting limits, there are similar rates for all aged buildings with maximum window sill dust lead

loading exceeding the standard of 250 μg/ft.

Table 5-3 . Distribution of dust lead loading by room and surface s

Dust Lead Loading Classroom Multipurpose Room All Rooms

(μg/sq g) Number of Percent of Number of Percent of Number of Percent of

Rooms Rooms (%) Rooms Rooms (%) Rooms Rooms %

Floors

LT LOD 250,200 82 51,400 78 301,600 81

GE LOD 54,500 18 14,800 22 69,200 19

GE Reporting Limit 1,400 1 1,800 3 3,200 1

GE 20 0 0 1,800 3 1,800 1

GE 40 0 0 0 0 0 0

GE 100 0 0 0 0 0 0

Missing 0 0 0 0 0 0

Total Rooms 304,600 100 66,100 100 370,800 100

Window Sills

LT LOD 128,300 42 21,000 32 149,300 40

GE LOD 131,400 43 27,300 41 158,800 43

GE Reporting Limit 50,600 17 12,100 18 62,700 17

GE 125 6,700 2 1,500 2 8,200 2

GE 250 2,700 1 1,500 2 4,300 1

GE 500 600 0 0 0 600 0

Missing 3,000 1 5,400 8 8,500 2

No Sills 41,900 14 12,400 19 54,300 15

Total Rooms 304,600 100 66,100 100 370,800 100

Values may not add to the total due to roundin g

Percentages use the number of rooms (304,600, 66,100, or 370,800) as the denominator

LT LOD = Less than the limit of detection

GE LOD = Greater than or equal to the limit of detectio n

Reporting limit = The lowest lead value a lab can confidently report for the wipe samples . The reporting limit was 10 μg . While

reporting limits for each surface are area dependent, this corresponds to a reporting limit of 10 μg/ftZ for a I square foot floor

sample or 20 μg/flZ for a typical 3" x 24" sill sample .

WESTAT 5-7 July 15, 2003
p. 47

First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

Table 5-4 . Maximum window sill dust lead loading by year of constructio n

Maximum Window Sill Lead Year of Construction All Centers

Loading s ft 1978 to 2001 1960 to 1977 Before 1960 Unknown

~μ~ a~ Number Percent Number Percent Number Percent Number Percent Number Percent

LT LOD Number Centers 13,700 41 7,400 32 8,000 27 1,200 8 30,200 30

Lower 95% Cl 7,700 25 2,900 18 5,300 20 16,800 1 22,500 23

Upper 95% CI 19,700 58 11,900 51 10,700 37 5,600 40 38,000 38

GE LOD Number Centers 12,600 37 12,000 52 19,900 68 10,800 76 55,300 55

Lower 95% Cl 5,900 23 7,100 39 14,000 58 5,400 47 44,100 48

U er 95% CI 19,300 54 16,900 66 25,800 77 16,100 92 66,500 62

GE Number Centers 4,700 14 3,500 15 11,200 38 5,400 38 24,800 25

Reporting Lower 95% CI 1,400 7 100 6 5,900 25 900 16 16,100 18

Limit Upper 95% CI 8,000 26 6,900 34 16,500 54 9,900 67 33,600 34

GE 1 25 Number Centers 1,200 3 800 3 2,800 10 0 0 4,700 5

Lower 95% Cl 300 1 100 1 900 3 0 0 900 2

Upper 95% Cl 4,200 12 6,900 18 7,900 27 4,600 33 8,600 to

GE 250 Number Centers 1,200 3 800 3 900 3 0 0 2,800 3

Lower 95% Cl 300 1 100 1 200 1 0 0 300 1

Upper 95% CI 4,200 12 4,100 18 3,700 13 4,600 33 5,400 7

GE 500 Number Centers 600 2 0 0 0 0 0 0 600 1

Lower 95% Cl 100 0 0 0 0 0 0 0 too 0

Upper 95% Cl 3,500 10 1 ,800 12 2,000 11 4,600 33 3,600 4

Missing Number Centers 1,500 4 1,200 5 0 0 900 7 3,600 4

No Sills Number Centers 5,900 18 2,300 10 1,300 4 1,300 9 10,700 1 1

Lower 95% Cl 2,500 10 200 4 39,500 1 19, 1 00 1 6,000 7

Upper 95% CI 9,400 29 4,400 23 4,000 14 5,800 41 15,500 16

Percent is number of centers as a percentage of all centers in the construction year category .

CI = Confidence limit for a 95% confidence interval for the estimated number or percent

LT LOD = Less than the limit of detectio n

GE LOD = Greater than or equal to the limit of detection

Values may not add to the total due to roundin g

Reporting limit = The lowest lead value a lab can confidently report for the wipe samples. The reporting limit was 10 μg . While

reporting limits for each surface are area dependent, this corresponds to a reporting limit of 10 μg/ft2 for a I square foot floor

sample or 20 μg/ft2 for a typical 3" x 24" sill sample .

Figure 5-1 shows the distribution of the dust lead loadings by room type : classroom and

multipurpose. Figure 5-2 shows the distribution of the dust lead measurements by surface . In both

figures, the distributions are somewhat right-skewed even after using the log transformation . None of the

boxes extend above 40 μg/W, which means that the 75thpercentile is less than 40 μg/ft' . However, there

are window sill dust lead loadings well above 100 μg/W .

Table 5-5 presents selected parameters of the distributions of dust lead loadings by surface

types, corresponding to the box plots in Figure 5-2 . Table 5-5 also presents geometric means and

standard deviations. The distributions in Table 5-5 are all right-skewed, so that they are not normally

distributed. A better model would be the log-normal distribution.

WESTAT 5-8 July 15, 2003
p. 48

First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

Figure 5-1 . Box plots for dust lead loading by room

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Room Type

Paint and dust lead loading data are presented in box plot form . Each box plot shows a univariate data distribution, for example, the dust samples

collected from a specific sample location (e.g ., classroom). The box in the box plot represents the middle 50 percent of the data ; the bottom of the

box gives the 25th percentile ; the top gives the 75th percentile; and the horizontal line inside the box gives the median or 50th percentile. The

vertical lines (whiskers) from the top and bottom of the box extend 1 .5 times the length of the box or to the largest and smallest observations,

whichever is closer. Individual observations beyond the whiskers are shown as dots. Data sets approximating a log-normal distribution will

produce a symmetrical box plot since the data are plotted on a logscale . From this display of the data, it is possible to visually compare lead

loadings between classrooms and multipurpose rooms .

WESTAT 5-9 July 15, 2003
p. 49

First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

Figure 5-2. Box plots for dust lead loading by surface

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Sample Location

Paint and dust lead loading data are presented in box plot form . Each box plot shows a univariate data distribution, for example, the dust samples

collected from a specific sample location (e .g., classroom floor) . The box in the box plot represents the middle 50 percent of the data ; the bottom

of the box gives the 25th percentile ; the top gives the 75th percentile; and the horizontal line inside the box gives the median or 50th percentile.

The vertical lines (whiskers) from the top and bottom of the box extend 1 .5 times the length of the box or to the largest and smallest observations,

whichever is closer. Individual observations beyond the whiskers are shown as dots. Data sets approximating a log-normal distribution will

produce a symmetrical box plot since the data are plotted on a logscale. From this display of the data, it is possible to visually compare lead

loadings between floors and window sills.

WESTAT 5-10 July 15, 2003
p. 50

First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

Table 5-5 . Estimated empirical distribution parameters of dust lead loading by surface type s

Floors Window Sills

μg/ft2 μg/ft2

Arithmetic Mean 1.3 20.5

Arithmetic Standard Deviation 2.0 84.6

Geometric Mean 0.8 2.7

Geometric Standard Deviation 2 .5 6. 3

25th Percentile 0.4 0.5

Median 0.6 2.4

75th Percentile 1.6 7.9

90th Percentile 2.6 31.3

95th Percentile 3.9 81.3

Maximum 27.5 1154.7

Number of Samples 336 273

For these calculations, negative and zero values were replaced by 0 .375 .

5.3 Association between Interior Dust Lead Hazards and Interior and Exterior Lead-Based

Paint Condition

Table 5-6 presents the prevalence of interior dust lead hazards in relation to the condition of

the interior and exterior LBP . Dust lead hazards are more likely to exist in homes with interior LBP6, and

the same is probably true in centers. An estimated 7 percent of centers with significantly deteriorated

interior LBP (6 percent of centers with interior LBP in good condition) have lead dust hazards . Only 2

percent of centers with no interior LBP have lead dust hazards. Given the small number of sampled

centers, this relationship is not strong. Although it appears from the data that the presence of interior LBP

is correlated with higher dust lead hazard, there are additional sources of lead in the environment to

account for dust lead in centers with no LBP . Dust lead hazards are due to sill dust in this survey. In

homes, interior LBP condition is more highly correlated with interior floor lead. Apparently because of

required daily cleaning in the centers, this association was not observed in CCCs .

Exterior LBP may contribute to interior dust lead, particularly on window sills that are the

primary source of dust hazards in CCCs. However, the data show no apparent relationship between the

presence and condition of exterior LBP and the interior dust lead hazards.

6 National Survey of Lead and Allergens in Housing, Volume 1: Analysis of Lead Hazards, Final Report, October 31, 2002, U .S . Department of

Housing and Urban Development .

WESTAT 5-11 July 15, 2003
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First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

Table 5-6. Association between dust lead hazards and presence and condition of inte rior and exte rior

LBP

Interi or LBP

Interior LBP in Good Significantl

y

No Interi

or LBP Condition Dete

ri orated Interi or

LBP

Number Percent Number Percent Number Percent

No Inte ri

or Dust Lead Estimate 77,800 98 14,900 95 4,500 94

Hazards Lower

95% Cl 67,000 94 9,400 79 267,700 56

Upper 95% Cl 88,600 99 20,300 99 474,700 99

Estimate 1,700 2 900 6 300 7

Interior Dust Lead

Lower 95% Cl 52,200 1 19,300 1 2,900 1

Hazards

Upper 95% CI 510,800 6 334,000 21 209,900 44

Number of Centers Estimate 79,400 100 15,700 100 4,800 100

Exte rior LBP

Exterior LBP in Good Significantl

y

No Exterior LBP Deteriorated Exterior

Condition LBP

Number Percent Number Percent Number Percent

No Inte rior Dust Lead

Estimate 77,600 97 9,500 97 10,000 100

Hazards Lower

95% Cl 66,700 92 4,000 81 3,500 65

Upper 95% Cl 88,600 99 14,900 100 16,600 100

Interi or Dust Lead

Estimate 2,500 3 300 3 0 0

Hazards Lower95% Cl 0 1 0 0 0 0

Upper 95% Cl 5,100 8 1,800 19 1,700 35

Number of Centers Estimate 80,200 100 9,800 100 10,000 100

CI = Confidence limit for a 95% confidence interval for the estimated number or percent

Values may not add to the total due to roundin g

Percentages use the number of centers in the bottom row of the section as the denominato r

5.4 Comparison of Dust Lead Hazard Prevalence Between Child Care Centers and Homes

Dust lead hazards are found more often in homes than in child care centers . An estimated

three percent (one to seven percent) of CCCs have dust lead hazards and no hazards were found on floors.

In comparison, 16 percent (14 to 19 percent) of homes were found to have dust lead hazards. Dust lead

hazards on floors were found in 6 percent of homes and hazards due to sills were found in 14 percent of

homes. Thus dust lead hazards due to sill dust is more common than due to floor dust, in both homes and

CCCs.

WESTAT 5-12 July 15, 2003
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First National Environmental Health Final Repo rt, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

6. CHILD CARE CENTER SOIL LEAD

Chapter 6 presents estimates of the prevalence of soil lead and the association between soil

lead concentration and exte rior lead-based paint (LBP) condition. The prevalence of soil lead hazards in

child care centers (CCCs) is presented in Chapter 3 .

6 .1 Prevalence of Soil Lead

A soil sample was collected on the property of each CCC in children's play area(s). Each

sample was a composite sample from three to five locations around the play area(s) . Bare soil was

sampled preferentially.

Table 6-1 presents the number and percentage of centers by selected soil lead concentration

thresholds : LOD', 50, 200, 400, 1,200, 1,600, 2,000, and 5,000 parts per million (ppm). Table 6-1

includes all soil, whether bare or covered . An estimated 48 percent (40% to 55%) of licensed CCCs in

the continental United States have soil lead levels above the limit of detection, but only an estimated 2

percent (1% to 6%)2 of centers have soil lead levels above 400 ppm, the current U.S. Department of

Housing and Urban Development (HUD)/U.S. Environmental Protection Agency (EPA) standard .

The sample limit of detection for this study was determined to be 20 parts per mi ll ion (ppm) by testing four distinct soil types from among the

National Survey of Lead and Allergens in Housing ( NSLAH) study samples in accordance with EPA SW 840 Method 3050 procedures.

z 95% confidence intervals are shown in parentheses .

WESTAT 6-1 July15, 2003
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First National Environmental Health Final Report, Vol. I

Survey of Child Care Centers Analysis of Lead Hazards

Table 6-1 . Distribution of soil sample (bare and covered) lead concentration s

Number of Centers Percent of Centers

Soil Lead Lower 95% Upper 95% Lower Upper

Estimate

Cl Cl

Estimate 95%

Cl 95% Cl

GE 0 ppm 71,900 60,400 83,500 72 62 80

GE LOD (20 ppm) 47,800 38,700 56,800 48 40 55

GE 50 ppm 20,600 10,200 31,000 21 12 32

GE 200 ppm 6,200 500 11,900 6 3 14

GE 400 ppm 2,100 700 6,400 2 1 6

GE 1,200 ppm 300 100 2,000 0 0 2

GE 1,600 ppm 300 100 2,000 0 0 2

GE 2,000 ppm 300 100 2,000 0 0 2

GE 5,000 ppm 0 0 3,700 0 0 4

Missing 600 1

No Soil in Play Area 23,400 12,800 33,900 23 15 34

No Play Area 4,100 900 7,200 4 2 9

Total 100,000 87,600 112,300 100

CI = Confidence limit for a 95% confidence interval for the estimated number or percent

Values may not add to the total due to roundin g

Percentages use 99,952 centers as the denominator

GE = Greater than or equal to

Table 6-2 presents the number and percentage of centers by selected soil lead concentration

thresholds for bare soil only. Only two percent of centers were found to have bare soil lead above 400

ppm.

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Table 6-2. Distribution of soil sample (bare soil only) lead concentrations

Number of Centers Percent of Centers

Soil Lead Lower 95% Upper 95% Lower Upper Estimate

Cl Cl Estimate 95% Cl 95% Cl

GE 0 ppm 68,400 58,000 78,700 68 59 76

GE LOD (20 ppm) 46,000 37,700 54,400 46 39 54

GE 50 ppm 20,200 10,200 30,100 20 12 31

GE 200 ppm 6,200 500 11,900 6 3 14

GE 400 ppm 2,100 700 6,400 2 1 6

GE 1,200 ppm 300 100 2,000 0 0 2

Missing 600 1

No Bare Soil 3,600 100 7,000 4 1 9

No Soil in Play Area 23,400 12,800 33,900 23 15 34

No Play Area 4,100 900 7,200 4 2 9

Total 100,000 87,600 112,300 100

CI = Confidence limit for a 95% confidence interval for the estimated number or percent

Values may not add to the total due to roundin g

Percentages use 99,952 centers as the denominator

GE = Greater than or equal t o

Table 6-3 presents the number and percentage of centers by construction year for selected

soil lead concentration thresholds for all soil, whether bare or covered . With the exception of one

sampled post-1978 center with high soil lead concentrations, in general, buildings build before 1960 tend

to have higher soil concentrations.

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Table 6-3. Distribution of soil sample (bare and covered) lead concentrations by construction yea r

Soil Lead Number of Centers Percent of Centers

Concentration Before 1960 to 1978 to Unknown All Centers Before 1960 to 1978 to Unknown All Centers

1960 1977 2001 1960 1977 2001

GE 0 ppm 21,000 15,600 23,700 11,600 71,900 72 68 70 82 72

GE LOD (20 ppm) 16,400 9,500 14,600 7,200 47,800 56 41 43 51 48

GE 50 ppm 10,600 2,600 3,900 3,500 20,600 36 11 12 25 21

GE 200 ppm 3,400 0 1,500 1,300 6,200 12 0 5 9 6

GE 400 ppm 1,800 0 300 0 2,100 6 0 1 0 2

GE 1,200 ppm 0 0 300 0 300 0 0 1 0 0

GE 1,600 ppm 0 0 300 0 300 0 0 1 0 0

GE 2,000 ppm 0 0 300 0 300 0 0 1 0 0

GE 5,000 ppm 0 0 0 0 0 0 0 0 0 0

Missing 0 0 600 0 600 0 0 2 0 1

No Soil in Play Area 6,600 6,100 8,600 2,100 23,400 23 27 26 15 23

No Play Area 1,600 1,200 800 500 4,100 5 5 2 3 4

Total 29,200 22,900 33,800 14,100 100,000 100 100 100 100 100

Percentage is number of centers as a percent of all centers in the construction year categor y

Values may not add to the total due to rounding

GE = Greater than or equal t o

Table 6-4 presents the number and percentage of centers by construction year for selected soil

lead concentration thresholds for bare soil only . As seen above for all soil, there is too little data to

observe any trends.

Table 6-4. Distribution of soil sample (bare soil only) lead concentrations by construction year

Bare Soil Lead Number of Centers Percent of Centers

Concentration Before 1960 to 1978 to Unknown All Centers Before 1960 to 1978 to U

nkn

o

wn

All

1960 1977 2001 1960 1977 2001 Centers

GE 0 ppm 21,000 15,200 21,900 10,300 68,400 72 66 65 73 68

GE LOD (20 ppm) 16,400 9,000 13,400 7,200 46,000 56 39 40 5 1 46

GE 50 ppm 10,600 2,100 3,900 3,500 20,200 36 9 12 25 20

GE 200 ppm 3,400 0 1,500 1,300 6,200 12 0 5 9 6

GE 400 ppm 1,800 0 300 0 2,100 6 0 1 0 2

GE 1,200 ppm 0 0 300 0 300 0 0 1 0 0

Missing 0 0 600 0 600 0 0 2 0 1

No Bare Soil 0 500 1,800 1,300 3,600 0 2 5 9 4

No Soil in Play Area 6,600 6,100 8,600 2,100 23,400 23 27 26 15 23

No Play Area 1,600 1,200 800 500 4,100 5 5 2 3 4

Total 29,200 22,900 33,800 14,100 100,000 100 100 100 100 100

Percentage is number of centers as a percent of all centers in the construction year category

Values may not add to the total due to rounding

GE = Greater than or equal to

Table 6-5 presents selected parameters of the distributions of soil lead concentrations . Table

6-5 also presents geometric means and standard deviations. As with the distributions of paint lead

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loadings and dust lead loadings, the distribution of soil lead concentrations is right-skewed. Thus, a

normal distribution would not be a suitable model for the distribution . A log-normal distribution would

be a more suitable distribution .

Table 6-5. Estimated empirical distribution parameters of soil lead concentrations

Play Area

ppm

Arithmetic Mean 81

Arithmetic Standard Deviation 329

Geometric Mean 28

Geometric Standard Deviation 3

25th Percentile 15

Median 28

75th Percentile 53

90th Percentile 124

95th Percentile 219

Maximum 3,582

Number of Samples 122

For these calculations, zero values were replaced by 5 .0 .

6.2 Association between Bare Soil Lead and Exterior Paint Condition

Table 6-6 shows the association between bare soil lead concentration and the condition of

the exterior LBP. Higher bare soil lead concentrations occur for centers with significantly deteriorated

exterior LBP. An estimated 17 percent (10% to 27%) of centers with intact or minimally-deteriorated

exterior LBP have bare soil lead above 50 ppm, while 46 percent (16% to 79%) of centers with

deteriorated exterior LBP have bare soil levels above 50 ppm . Only 2 and 0 percent of centers without

significantly deteriorated exterior LBP have bare soil lead levels above 200 and 400 ppm, respectively,

while 39 and 16 percent of centers with deteriorated exterior LBP have bare soil lead levels above 200

and 400 ppm, respectively .

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Table 6-6. Association between bare soil lead concentration and presence of significantly deteriorated

exterior LBP

Centers without Significantly Centers with Significantly

Bare Soil Lead Deteriorated Exterior LBP Deteriorated Exterior LBP

Percent Lower Upper

Percent

Lower Upper

95% Cl 95% Cl 95% Cl 95% Cl

GE 0 ppm 68 58 77 68 35 90

GE LOD (20 ppm) 45 37 54 52 20 83

GE 50 ppm 17 10 27 46 16 79

GE 200 ppm 2 1 5 39 11 76

GE 400 ppm 0 0 2 16 4 42

GE 1,200 ppm 0 0 2 0 0 4

Missing 1 0 4 0 0 4

No Bare Soil 3 1 7 11 2 49

No Soil in Play Area 24 16 35 18 5 47

No Play Area 4 2 9 3 0 16

Total 100 100

Cl = Confidence limit for a 95% confidence interval for the estimated number or percent

Values may not add to the total due to roundin g

Percentages use 99,952 centers as the denominator

GE = Greater than or equal to

6.3 Comparison of Soil Lead Hazard Prevalence Between Child Care Centers and Homes

Soil lead hazards are found more often in homes than in CCCs . An estimated two percent

(one to six percent) of CCCs have soil lead hazards . In comparison, 10 percent (7 to 14 percent) of homes

were found to have soil lead hazards . Due to the small number of CCCs with a soil lead hazard, more

detailed comparisons are not possible .

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7 . QUALITATIVE SUMMARY OF SOURCES OF ERRO R

Chapter 7 examines the quality of the data and the resulting quality of projected national

estimates. The greatest source of error in the First National Environmental Health Survey of Child Care

Centers (referred to here as the CCC Survey) estimates is sampling error-as discussed in Volume III,

Chapter 2 . This chapter addresses two additional important potential sources of error - nonresponse bias

and measurement bias-and discusses their effects on the national estimates of the prevalence of leadbased paint (LBP), lead in dust, and lead in soil . '

The chapter concludes with a summary of the data collection quality assurance activities,

including results of telephone verification, field team audits, field dust and soil quality control samples,

laboratory performance on dust and soil quality control samples, and paint testing quality control.

7 .1 Statistical Concepts and Terminology

There are two broad types of error in survey estimates: sampling error and nonsampling

error.

■ Sampling Error. Sampling error arises from surveying a random sample rather than a

complete census of all centers. It is a function of the sample size and sample design .

Different samples of the same size drawn using the same sample design will yield

varying estimates of the population parameters. This variation about the true population

parameter is the sampling error.

■ Nonsampling Error. Nonsampling errors arise from a number of sources including

differential response rates from different demographic groups, types of centers, and

geographical areas; unknown differences between the respondents and nonrespondents ;

differences between the sample frame and the target population ; some types of

processing and data reduction techniques ; and classification bias due to measurement

error inherent in XRF and laboratory instrumentation and variation in a measured

parameter across a surface and among rooms .

Throughout the report, the term weight has been used in conjunction with the sampled

centers and rooms. It is important that these terms be understood .

Another source of error in the survey is response bias (i.e ., how correct was the information provided by the respondents?). Significant

information obtained from respondents included year of construction of the building . These data are thus associated with an unknown amount

of error. These data were partially verified by other means to help control any error (see Volume III for details) .

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■ Center Weight: The center weight is the number of centers in the target population that

a single center in the survey represents. The weight is calculated by taking the inverse

of the probabili ty of selection for that unit. Thus, if the probability of selection is 0.01,

the sample weight is 100 . With multistage samples, the overall probability of selection

is the product of the conditional probabilities of selection at each stage .

■ Room Weight: The room weight is the number of rooms in the target population that a

single room in the survey represents. Room weights were determined by dividing the

center weights by the probability of room selection based on the inventory of all rooms

used by children under age 6 in each center. A nonresponse adjustment was then made

to account for noncompleted rooms. A room was only considered to be complete if some

environmental samples and data were collected in the room .

7.2 Potential for Nonresponse Bia s

Completion rates were calculated as the unweighted propo rtion of sampled centers that

completed data collection or were found to be ineligible . Of the 334 centers sampled, 168 completed data

collection and 68 were found to be ineligible . The remaining 98 did not complete the data collection, but

were determined to be eligible . The completion rate for the survey was 70.7 percent.

The formula for the unweighted completion rate is given below along with the eligibili ty rate

and response rate.

# com letes + # ineli ible 168 + 68

Completion Rate =100% x p g =100% x = 70.7%

# fielded 334

Eligibility was determined for all fielded cases . Nonrespondents were asked enough

questions to determine their eligibility. The eligibility rate was 79 .6 percent.

Eligibility Rate = 100% x # eligible = 100% x 266 = 79.6%

# eligible + # ineligible 266 + 6 8

The response rate measures the response among eligible CCCs. The response rate for the

survey was 63 .2 percent.

Response Rate = 100% x # eligible completes = 100% x 168 = 63.2%

# eligible completes + # ineligible completes 168 + 98

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The weights are constructed to weight the responding CCCs up to the total population . The

weights adjust for nonresponse based on the assumption that, within groups of similar CCCs, the

respondents are similar to the nonrespondents. The estimates calculated using the weights might be

biased if this assumption is incorrect.

In addition, the weights are calculated assuming that the population is not changing over

time. However, CCCs open and close over time and the state lists of CCCs (from which the centers were

sampled) may not be up to date . This can create additional uncertainty in the estimates that is not

reflected in the confidence intervals.

7.3 Correcting for Classification Bias Due to Measurement Erro r

Centers were classified as having LBP and lead hazards based on the XRF readings of paint

and the analysis of dust and soil samples. Random variation associated with instrument or laboratory

measurement, sample collection, and random selection of sampling locations can induce a classification

bias resulting in a bias in the estimated prevalence of centers with LBP and lead hazards . As a general

rule, small percentage estimates will overestimate the true percentage of centers and large percentage

estimates will underestimate the true percentage. This can be illustrated using the following hypothetical

example. Assume that, within a group of centers, 2 percent have a soil lead hazard and 98 percent do not .

Also assume that on average one percent of the centers are misclassified due to measurement error . The

expected percentage of centers classified as having a soil lead hazard based on the observed

measurements is the sum of (1) the centers without a soil lead hazard that are misclassified as having a

soil lead hazard and (2) the centers with a soil lead hazard that are correctly classified . The relevant

calculations are shown in the Table 7-1 . Due to misclassification, three percent of hypothesized centers

are classified as having a soil lead hazard when only 2 percent actually have a soil lead hazard. Similarly,

97 percent are classified as not having a soil lead hazard when 98 percent actually do not have a soil lead

hazard.

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Table 7-1 . Effect of measurement error on the percentage of centers (hypothetical example, assumes 1%

misclassification rate)

Soil Hazard According to

True Soil Percent of Measurements

Hazard Centers Yes No

Yes 2% 1.98% 0.02%

No 98% 0.98% 97.02%

Total 100.0% 2.96% 97.04%

In the survey data, 2 percent of CCCs are estimated to have soil lead hazards . Because the

soil measurements have measurement error, the true proportion of CCCs with soil lead hazards is more

likely to be less than 2 percent than greater than 2 percent . Similar statements apply to the percentage of

centers with dust lead and paint lead hazards . Estimates of the variance of the data and the variance of the

measurement error suggest that the bias in the number and percentage of centers with soil and dust

hazards is likely to be small . Rough estimates of the bias for classifying CCCs with LBP are difficult to

calculate and have not been obtained.

In addition, paint and dust measurements were made in a sample of rooms-not all rooms.

Under this protocol, it is possible for a center to have LBP or a LBP dust hazard in an unsampled room .

When no lead-based paint and/or no dust-lead hazard is found in the sampled room such centers would be

incorrectly classified as not having LBP and/or LBP hazards (false negatives) . Assessing the effect of

incomplete sampling of rooms on the percentage of centers with LBP and dust lead hazards is difficult .

However, a conservative estimate (based on the fact that approximately half of all rooms were sampled) is

that the true percentage of centers is no greater than twice the estimated percentage for small

percentages.2 Since the percentage of centers with LBP or dust hazards is relatively small, the bias due to

sampling and measurement error and the bias due to incomplete sampling of rooms will tend to cancel

each other out. As a result, bias in the number and percent of centers with LBP and dust hazards is

expected to be small compared to the width of the confidence intervals .

2 Among centers with a hazard, if the hazard is in only one room and half of all rooms are sampled then the estimated number of centers in which

a hazard is identified will be half the actual number . Since centers with a hazard in one room are likely to have a hazard in other rooms, the

true number of centers with a hazard will be less than twice the estimated number .

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7.4 Quality of Field Data Collection and Analysis for Lead Samples and Measurement s

Quality assurance was integrated into all components of the study including a defensible

study design; experienced project personnel ; utilization of well-planned, detailed, and tested protocols for

all aspects of data collection; thorough study-specific training of experienced field staff; electronic sample

and data management; and ongoing communication between individuals responsible for each stage of the

study. These procedures are described in detail in Volume III, Chapter 6.

7.4.1 Field Data Collectio n

A number of procedures were instituted to ensure quality of the field data collection

including a manual edit of all data and samples by the field team, review by the field supervisor upon

return of the data to Westat headquarters, and reconciliation of any errors with the field team prior to

submission of any samples to the laboratory. In addition, random telephone verification and field team

audits were conducted, dust sample material screens were analyzed, and dust blanks and spike samples

and blind soil reference samples were included in the sample stream .

Telephone Verification of Data Collection

The telephone interviewers contacted each center director by telephone to verify the team's

activities and conduct and to validate selected information from the data forms . No problems associated

with sample or data quality were reported.

Random Field Audits

The Quality Assurance Officer or designee, and the U .S. Department of Housing and Urban

Development (HUD) and the U.S. Environmental Protection Agency (EPA) representatives conducted

random field audits at 13 centers to verify that the protocols were followed and data collection was

accurate and complete . Problems noted during these audits were corrected directly with the individual

technicians. In addition, the results of audits were immediately relayed to the field office . As

appropriate, all field staff were notified by memorandum of any issues identified with the protocols .

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Lead Dust Wipe Sample Collectio n

■ Lead Dust Wipe Materials Screens. The purpose of a materials screen (or lot blank)

was to verify that the various sampling supplies to be used in the field did not have lead

contamination. Two screens were prepared and analyzed for every lot of wipe materials

and sample tubes before being used in the study. The analyses showed that all material

screens had less than 1 .5 μg lead. '

■ Field Blank Wipes. One field blank wipe was prepared for each center at a specified

random sample location where a wipe sample was collected . All field blanks were below

4 .2 μg lead/wipe. In fact, the majority (143 samples) had less than 1 .0 μg lead/wipe.

■ Reference (Spike) Sample Dust Wipes. Reference wipe samples were made in advance

of the fieldwork by placing a known quantity of National Institute of Standards and

Technology's Standard Reference Material (NIST SRM) 1579a on the same wipe

material used in the study. The reference wipes were labeled like a regular sample so that

the laboratory was blinded to fact that these were quality control samples. The Field

Office inserted one reference wipe sample with each group of 50 samples before sending

samples to the laboratory . A total of 15 reference wipes, ranging from 28 to 316 μg

lead/wipe, were submitted . The average reference sample recovery was 93 percent

(range from 88% to 98%).

Soil Quality Control Samples

■ Reference Soil Samples. Reference soil samples were urban soil provided by the

University of Cincinnati (one sample with 640 ; two samples with 3,132; and one sample

with 6,090 ppm lead).4 The Field Office labeled and included one reference sample with

each group of 50 samples. The average recovery was 111 percent (range 110% to 112%).

7.4.2 Laboratory Quality Control Sample s

Each laboratory provided quality assurance procedures during the selection and qualification

process. These approved procedures (outlined in the CCC Survey's Protocol and Sample Design Report,

December 2001) were adhered to for all study samples. In, general, the laboratories performed

instrumental and duplicate quality control analyses, as required by ASTM E 1613-94 and the American

Industrial Hygiene Association's Environmental Lead Laboratory Accreditation Program (ELLAP)

Quality Manual and Policies, to ensure that the original calibration solutions were accurate, the

instruments were properly zeroed, instrumental drift was not excessive, and carryover between samples

3 EPA's National Lead Laboratory Accreditation Program (NLLAP) requires wipes to be used in the field to have less than 5 μg lead/wipe .

° No appropriate soil standards with lower lead concentrations were available .

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did not occur . These included duplicate injections of the same sample, method blanks, and spiked

samples at a minimum frequency of five percent of the samples .

7.4.3 Laboratory Selection Quality Assurance

The laboratories used for analysis of dust and soil samples, respectively, were recognized by

the EPA under its National Lead Laboratory Accreditation Program (NLLAP) for those analyses

throughout the laborato ry qualification and performance phases of the CCC Survey . This recognition

provided assurance of the quality of laboratory performance of lead analyses and reporting . In addition,

the laborato ries were accredited by the American Industrial Hygiene Association ; this accreditation

provided a separate assurance of the quality of laboratory management and performance of environmental

analyses and reporting.

7.4.4 Paint Testing Quality Assuranc e

Calibration of the XRF analyzer was performed before and after testing in eve ry center . In

no case was the instrument used if the calibration criteria were not met ; that is, the analyzer read 0 .0

mg/cmz on the 0.0 film and between 0.9 and 1 .2 mg/cm2 on both the front and back of the 1 .0 film. In

addition, the average of three more readings on the front of the 1 .0 film was between 0 .9 and 1 .2 mg/cmZ.

The calibration of the XRF instruments was checked before and after making XRF paint lead

measurements at the CCC. The calibration procedures were as follows. If the instrument did not pass the

first calibration check, the calibration was checked a second time . If the second calibration was not

within the desired limits the instrument was turned off and turned back on and the calibration was

checked a third time . If the instrument failed the third calibration the instrument was not used until it was

checked and/or repaired. If the instrument passed the third calibration it was considered properly

calibrated and was used for paint testing .

For each calibration check, HUD requires that a sequence of three measurements on the 1 .0

mg/cmZ calibration film have an average reading between 0 .9 and 1 .2 mg/cm2 inclusive. The XRF

manufacturer recommended also testing the back of the 1 .0 mg/cmZ film and checking a 0 .0 mg/cmZ film.

The survey procedures included these recommended tests. The third calibration check was required in

only one case and the instrument passed that calibration check. In no cases did the instrument fail the

third calibration check or require additional checking or repair . However, in 16 of 345 calibrations the

calibration information was not taken or recorded according to the survey procedures. In 11 cases the

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first calibration check passed the HUD calibration criteria but not the manufacturer's recommended tests

and a second calibration check was either not performed or not recorded . In one case the second

calibration check passed the HUD calibration criteria but not the manufacturer's recommended tests and a

third calibration check was either not performed or not recorded . In four cases the first calibration did not

pass the HUD calibration criteria but did pass the manufacturer's recommended tests and a second

calibration check was either not performed or not recorded . Whether the instrument failed calibration

check was based on the information written on the XRF calibration form . In several cases the instrument

was judged to fail the calibration check because some lines on the form were not completed . In these

cases the calibration procedure may have been completed without having all the information entered on

the form.

After reviewing the calibration data and the XRF measurements at the centers where there

was a problem with the calibration procedure, no problem was found that suggests that the XRF data for

those CCCs with calibration problems are not as good as the data from other centers .

WESTAT 7-8 July 15, 2003