### P
. 1

First National Environmental Health Survey



### of Child Care Centers FINAL REPORT July 15, 200 3 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, S W 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-21356p . 2

First National Environmental Health Final Repo rt, Vol. I Surv ey of Child Care Centers Analysis of Lead Hazard s


### 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 Repo rt 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 Compari son of Dust Lead Hazard Prevalence Between Child Care Center s 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 ri or Paint Condition
. . . . . . . . . . . . . . . . . . 6-5 6 .3 Comparison of Soil Lead Hazard Prevalence Between Child Care Centers and Homes . . .. . . . . . . .. . .. . . . . . . . . . . . . . . . . . . .. . .. . . . . . . .. . .. . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . 6-6

WESTAT ii July 15, 2003p . 3

First National Environmental Health Final Repo rt, Vol. I Surv ey of Child Care Centers Analysis of Lead Hazard s


### TABLE OF CONTENTS ( continued ) Ch ater 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 Laborato ry Quali ty Control Samples
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-6 7 .4 .3 Laborato ry Selection Quali ty Assurance

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-7 7 .4 .4 Paint Testing Quality Assurance . . . . . . . . . . . . . . .. . .. . . . . . . . . . .. . . . . . . . . . .. . .. . . . . . . . . . .. . .. . . . . . 7-7

LIST OF TABLE S 

### Table pa 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 selecte d

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 Distri bution of centers with deteriorated and significantly dete ri orated 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 ty pes . . . . . . . . . . . . . . . . . . . . . . . . . .. . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9 4-8 Estimated empi rical distri bution 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, 2003p . 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 Pa g 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 empirical 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 empi rical distri bution parameters of soil lead concentrations . . . . . . . . . . .. . .. . . . . . . . . . 6-5 6-6 Association between bare soil lead concentration and presence o f

signi fi cantly dete riorated 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 FIGURE S 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

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1 0



### WESTAT iv July 15, 2003p . 5

First National Environmental Health Final Report, Vol . I Surv ey 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 Hazard s 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, 2003p . 6

First National Environmental Health Final Repo rt , Vol . I Surv ey of Child Care Centers Analysis of Lead Hazard s



### ■ 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 Af rican 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, 2003p . 7

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 center s 

### with dust lead = hazard (3% 11,400 centers with 4100 centers Iith 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, 2003p . 8

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 Lea d 

### 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, 2003p . 9

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, 2003P
. 10

First National Environmental Health Final Report, Vol . I Survey of Child Care Centers Analysis of Lead Hazards

1 . INTRODUCTIO N 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 Backgroun d



### 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
. 

### WESTAT 1-1 July 15, 2003P . 11

First National Environmental Health Final Report, Vol . I Survey of Child Care Centers Analysis of Lead Hazards
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
. 

### WESTAT 1-2 July 15, 2003p . 12

First National Environmental Health Final Report, Vol . I Survey of Child Care Centers Analysis of Lead Hazards
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 Objective s



### 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) ; an d ■ 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
. 

### WESTAT 1-3 July 15, 2003p . 13

First National Environmental Health Final Report, Vol . I Survey of Child Care Centers Analysis of Lead Hazards

1 .3 Report Organizatio n

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

. 

### WESTAT 1-4 July 15, 2003p . 14

First National Environmental Health Final Report, Vol . I Survey of Child Care Centers Analysis of Lead Hazards
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 gove

### rnment 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, 2003p . 15

First National Environmental Health Final Repo rt , Vol . I Survey of Child Care Centers Analysis of Lead Hazards
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 rv ing 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 suppo rt 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 characteristics 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, 2003p . 16

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 center s 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/Wes t 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 Urbanizatio n 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 fro m 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
WESTAT 2-3 July 15, 2003p . 17

First National Environmental Health Final Report, Vol . I Surv ey of Child Care Centers Analysis of Lead Hazards
Table 2-1 . National surv ey 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 Ownershi p Private 78,900 79 69 86 134 Govern ment 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 Bloo d 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% con fi 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, 2003p . 18

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/Wes t 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 Urbanizatio n 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 fro m 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, 2003P
. 19

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 (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't Know 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 percen t 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, 2003p . 20

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 Hazard s

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

. 

### WESTAT 3-1 July 15, 2003p . 21

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, 2003p . 22

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 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 Urbanizatio n 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 fro m 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, 2003p . 23

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 wit h 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 denominato r



### WESTAT 3-4 July 15, 2003

### p . 24

First National Environmental Health Final Report , Vol . I Survey of Child Care Centers Analysis of Lead Hazard s

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 Sample Estimate 95% Cl 95% Cl Percent 95% Cl 95% C l 

### 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% confi dence 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, 2003p . 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 LB P (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, 2003p . 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 Home s

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 Urbanizatio n 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 2 7



### WESTAT 3-7 July 15, 2003p . 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 Ownershi p 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, 2003p . 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 denominato r



### WESTAT 4-3 July 15, 2003p . 30

First National Environmental Health Final Report, Vol . I Surv ey of Child Care Centers Analysis of Lead Hazards

4.2 Prevalence of Deteriorated Lead-Based Pain t

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 ri sk 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 deteri orated LBP and significantly deteriorated (more than the de minimis amounts) LBP by location in the building--either interior or exte ri or, 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 Deteriorated 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% C l 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 percen t 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 dete riorated LBP is on the exteri or for over half of
WESTAT 4-4 July 15, 2003p . 31

First National Environmental Health Final Repo rt , 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 deteri orated LBP by construction year . The data suggest that older buildings are more likely to have deteri orated LBP than newer ones . One percent of post-1978 buildings have deteriorated LBP and four percent of centers build between 1960 and 1977 have dete ri orated 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 LB P

Number of Centers with Deteriorated Percent wit h 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% C l 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% con fidence 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 summari zes the above su rvey 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, 2003p . 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 LB P 50,000 ❑ Undamaged LB P 

### y De minimis deterioration 4) ■ Significant deterioration a w 40,00 0 

### a~ d L ' a V 3 

## ~ 30,000

~ L V 

## V C L L V I 

## ~ = 20,00 0 7 Z 

## 10,000

_

Unknown Before 1960 1960 to 1977 1978 to 2001

Building construction yea r

4 .3 Paint Lead Loadings in Center s

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, 2003p . 33

First National Environmental Health Final Repo rt , Vol . I Surv ey 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 Anywher e 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 1 8 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 pain t Cl = Con fi dence limit for a 95% confidence interv al 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, 2003p . 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 denominato r



### WESTAT 4-8 July 15, 2003p . 35

First National Environmental Health Final Report, Vol . I Survey of Child Care Centers Analysis of Lead Hazard s



### 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/cm Z 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, 2003p . 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

constructio n Component Type Year of Constructio n 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 1 5 All Exteri or Components 5 11 28 38 1 7 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, 2003p . 37

First National Environmental Health Final Report, Vol . I Survey of Child Care Centers Analysis of Lead Hazard s

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 LB P 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, 2003p . 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 42 1 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, 2003p . 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 4 0 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 ri orated LBP All Centers or Homes 11 6 20 14 12 1 7

WESTAT 4-13 July 15, 2003p . 40

First National Environmental Health Final Repo rt , Vol. I Surv ey 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 Center s



### 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, 2003p . 41

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% C l 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, 2003p . 42

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 Lea d 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't Know 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 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 (left end of the row) as the denominato r



### WESTAT 5-3 July 15, 2003p . 43

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 Center s



### 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, 2003p . 44

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 Report ing 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 Sill s 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 Report ing limit = The lowest lead value a lab can confidently repo rt for the wipe samples . The report ing limit was 10 μg . While report ing 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, 2003p . 45

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 rt ing 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 rt ing 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 Sill s 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 interv al 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 report ing 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 Room s (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 Sill s 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 Unknow n

~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 3 8 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, 2003p . 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 roo m



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0 .01 Classroom Multipurpose oom Room Typ e 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, 2003p . 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 surfac e



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## Sample Locatio n
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, 2003p . 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 Conditio n 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

### p . 51

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 Significantly No Interi or LBP Condition Dete ri orated Interi or LBP Number Percent Number Percent Number Percen t 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 9 9 Estimate 1,700 2 900 6 300 7 Interi or 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 ri or LBP Exterior LBP in Good Significantly No Exteri or LBP Deteriorated Exterior Condition LBP Number Percent Number Percent Number Percen t No Inte ri or 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 10 0 Interi or Dust Lead Estimate 2,500 3 300 3 0 0 Hazards Lower 95% Cl 0 1 0 0 0 0

Upper 95% Cl 5,100 8 1,800 19 1,700 3 5 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

### p . 52

First National Environmental Health Final Repo rt , Vol . I Survey of Child Care Centers Analysis of Lead Hazards
6. CHILD CARE CENTER SOIL LEA D 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 Lea d



### 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 fr om 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 July 15, 2003p . 53

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.

WESTAT 6-2 July 15, 2003

### p . 54

First National Environmental Health Final Report, Vol . I Survey of Child Care Centers Analysis of Lead Hazards
Table 6-2 . Distribution of soil sample (bare soil only) 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 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 10 0 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
.

WESTAT 6-3 July 15, 2003

### p . 55

First National Environmental Health Final Report, Vol . I Survey of Child Care Centers Analysis of Lead Hazards
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 200 1 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 Center s Concentration Before 1960 to 1978 to Unknown All Centers Before 1960 to 1978 to U nkno 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 WESTAT 6-4 July 15, 2003

### p . 56

First National Environmental Health Final Report, Vol . I Survey of Child Care Centers Analysis of Lead Hazards 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
.



### WESTAT 6-5 July 15, 2003p . 57

First National Environmental Health Final Report, Vol . I Survey of Child Care Centers Analysis of Lead Hazards
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 10 0 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
.

WESTAT 6-6 July 15, 2003p . 58

First National Environmental Health Final Report, Vol . I Survey of Child Care Centers Analysis of Lead Hazards

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 biasand 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 Terminolog y

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 su rvey represents . The weight is calculated by taking the inverse of the probabili ty of selection for that unit. Thus, if the probabili ty 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 surv ey 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 33 4 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 # eli gible = 100% x 266 = 79 .6% # eligible + # ineligible 266 + 6 8
The response rate measures the response among eligible CCCs
. The response rate for the surv ey was 63 .2 percent. 

### Response Rate = 100% x # elig ible 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 surv ey procedures . In 11 cases the WESTAT 7-7 July 15, 2003p . 65

First National Environmental Health Final Report, Vol . I Survey of Child Care Centers Analysis of Lead Hazards 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
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