FINAL REPORT

on

ELECTROSTATIC CLOTH A ND WET CLOTHS FIELD STUDY IN RESIDENTIA L HOUSING

EPA Contract No. EP-W-04- 021 Work A ssignment 1- 07

Prepared for
Daniel M. R

einhart EPA Work A

ssignment M anager

Prepared by
BATTELLE 505 King Avenue Columbus, Ohio 43201

December 28, 2005Final Report i Decem ber 28, 2005 TAB LE OF CONTENT S Page

EXECUTI VE SUMMARY

............ ............ ............ ............ ............ . . iii

1.0 OBJECTIVE

............ ............ ............ ............ ............ ..... 1
2.0 BACKGROUND

............ ............ ............ ............ ............ ... 1 2.1 EPA Purpose

............ ............ ............ ............ .......... 1 2.2 Histo ry and Moti vati on for Deve lopment of W hit e Glove Cl earance Test wit h Disposabl e Cleani ng Clot hs

............ ............ ............ ... 2 2.2.1 Descript ion of the Pr otocol

............ ............ ............ ..... 3 2.2.2 Potent ial Issues wi th t he Prot ocol

............ ............ ............ 3 2.3 Su m m ary of P rior W ork Co m pleted to Da te

............ ............ ........... 5

2.3.1 Round Robin St udy

............ ............ ............ ........... 6 2.3.2 First

Control led Room Study

............ ............ ............ .... 7 2.3.3 Pil ot Fi eld St udy i n Vacant Bui ldi ngs

............ ............ .......... 9 2.3.4 Second Control led Room Study

............ ............ ............ 11
3.0 STUD Y D ESI GN

............ ............ ............ ............ ............ . 14 3.1 Study

Data Quali ty

Objecti ves

............ ............ ............ ........ 15 3.2 DCC/W G Clearance Prot ocol as Implemented i n the Fi eld St udy

............ ..... 16 3.3 Implemented Fiel d Study

............ ............ ............ ............ 19 3.4 QAPP M odif icat ions

............ ............ ............ ............ .... 22
4.0 FI EL D DA TA C OLL ECTI ON

............ ............ ............ ............ .... 25 4.1 Sit e Select ion

............ ............ ............ ............ ......... 25 4.2 Sam pli ng Locati ons and Condit ions

............ ............ ............ .... 26
5.0 LA BO RA TO RY AN AL YSIS

............ ............ ............ ............ ..... 29 5.1 Review of

Analyti cal Met hods

............ ............ ............ ......... 29 5.2 Lab orato ry QC Re sults

............ ............ ............ ............ . . 29
6.0 ANAL YSI S RES ULTS

............ ............ ............ ............ ......... 33 6.1 Gr aph ical an d T abu lar Su m m aries of R esu lts

............ ............ ........ 33 6.2 Resu lts by Data Q uality Objec tive

............ ............ ............ ..... 39 6.2.1 Data Quali ty Objecti ve 1

............ ............ ............ ...... 39 6.2.2 Data Quali ty Objecti ve 2

............ ............ ............ ...... 41 6.2.3 Data Quali ty Objecti ve 3

............ ............ ............ ...... 46 6.2.4 Data Quali ty Objecti ve 4

............ ............ ............ ...... 50 6.3 Addit ional Result s and Discussi on

............ ............ ............ ..... 51 6.3.1 Effectof Reachi ng W hit e Glove on Ef fi cacy of

Treatment

............ .... 52 6.3.2 Representat ive ness of Fi eld St udy Loca ti ons to R&R Popula ti on

........... 52
7.0 CONCLUSI ONS

............ ............ ............ ............ ............ . 54
8.0 PEER REVIEW

............ ............ ............ ............ ............ . . 56 8.1 Peer Revi ew Background

............ ............ ............ ............ 56 8.2 Pe er R eview Re sults

............ ............ ............ ............ ... 57
9.0 QUALI TY AS SURANCE

............ ............ ............ ............ ....... 60Final Report ii Decem ber 28, 2005 TABLE OF CONTENTS (co nti nued) Page

List of Figures Figur e 1. W hit e Glove Cl earance Testi ng Prot ocol i n an R&R Environ ment

............ ..... 4 Figur e 2. W hit e Glove Cl earance Testi ng Prot ocol f or Fi eld St udy i n Resident ial Housing

............ ............ ............ ............ ............ . 17 Figur e 3. Process Fl ow Diagram of Sampli ng for Resi denti al Fi eld St udy

............ ...... 21

List of Tables
Table 1. Fiel d Study Floor Sampling

............ ............ ............ .......... 27 Table 2. Fiel d Study Sil l Sampli ng

............ ............ ............ ............ 28 Table 3. Field B lank Sam ple R esu lts

............ ............ ............ .......... 30 Table 4. Sam pli ng Result s from Batte ll e Laborat ory Spike QC Sam ples

............ ...... 31 Table 5. An alytical Lab orato ry QC Sam ple R esu lts

............ ............ ........... 32 Table 6. Co unts of S urfa ces Ov er or Un der C leara nce Stan dard s by T reatm ent,

Pre-Prot ocol Le ad Loadi ng, and White Glov e Stat us

............ ............ ... 37 Table 7. Overall DCC/W G Clearance Prot ocol Success Rates byTreatment

............ ... 38 Table 8. C ov ar iate Le ve ls fo r D C C /W G Cle ar an ce Pr oto co l Fa ilure s C om pa re d to All

Surfaces

............ ............ ............ ............ ............ . 48 Table 9. Compariso n of Wet DCC/W G Clear ance Pr oto col Perf ormance wi th Two Com merciall y Avai labl e Cleani ng Solut ions an d W ater

............ ............ . 49 Table 10. Average Number of DCCs Used

............ ............ ............ ...... 51
List of Appendices Appendi x A. Quali ty Assurance Proj ect Pl an Appendi x B. Roun d Rob in Study Report App end i x C. First Controlled Room Study Report App end i x D. Armstrong/Seneca Pil ot Fi eld St udy Pr esentat ion Appendi x E. Secon d Con troll ed Ro om Study Report Appen di x F. Sa m ple D ata Ap pe nd i x G. Photograp hs for Floors1 Window trou ghs are part of le ad abate

ment clea rance t esting b ut were n ot include d in this study because EPA does not intend to

regula te them in r

enovation and rem

odeling situations

. Final Report iii Decem ber 28, 2005 EXECUTIVE SUMMARY An innovative approach to lead clearanc e testing was developed and tested for use after renovation and remodeling projects. This new appr oach to clearance testing is intended to ser ve as an alternative to the wipe sampling clear ance method currently

recommended after renovation and remodeling projects. I t is hoped that the new approach will provide a viable alterna tive method for lead clearance testing that is faster and less expensive than the current method. The new metho d was test

ed on floors and win

dow sills 1 at 31 u rban re siden tial sites in tw o large urban cities where lead hazard reduc tion work had recently

been conducted.
The new lead clearance

protocol was tested with dry electrostatic and wet deterge nt-based disposabl e clean

ing clot hs (DCCs). Althoug

h DCCs wer

e develo ped for l ight hous ehold cleanin g, they were us ed here

as samplin

g tools in the new c learance proto col. The DCC products employed for

this study were all commer cially available

products purchased at local retail st ores. The new clearance protocol utilizes a DCC to sample an entire f loor or window sill, and a visual assessment of the used DCC follows. If the DCC looks dirty or discolored (compared to a refer ence sta ndard), resampli

ng with a fresh DC C is requir

ed. When the DCC rema ins near ly white after use, the surface is judge d clean enough to pass clearanc e. The visual assessment has been na med the ‘ white g love’ te st and the new cle arance

testing method is c alled the

disposabl e cleaning cloth/white glove (DCC/WG) cleara nce protocol. With the DCC/WG clearance protocol, an entire floor or window sill is sampled rather than sampling a sma ll area. Therefore, the judgment about the used DCC passing or failing White glove reflects the status of the entire floor or window sill surface. The central question asked by this field study is whether sampling w ith DCCs and passing the white glove test is indicative that the floor or window sill would pass standard clearance testing with wipes. Side-by -side pairs of wipe samples were collected be fore and after each DCC/WG clearance protocol and ana lyzed for lead c ontent to evaluate the efficacy of the new clearance method. Of par ticular interest was an assessment of whether the a verage lead loading from the two ASTM wipe samples fell below 40 μg/ft 2 for floors and below 250 μg/ft 2 for windo w sills.
The resu lts of this f

ield study indicate that the D CC/WG clea

rance p rotocol o ffers a promising alternative for clearanc e testing of smooth and cleanable surfac es in residential renovation and remodeling projects. The data demonstrate that when white glove is achieved, the new protocol affords a quick, low-cost, and re asonably ac curate method for concluding that lead cle arance

standar ds have b een met f

or floor s and wind

ow sills.Final Report 1 Decem ber 28, 2005

1.0 OB

JE CTIVE The objective of the current field study in residential housing is to determine to what extent, and under what conditions within renovation and remodeling (R&R) work, a n electrostatic cloth/wet cloth clearance pr otocol used along with a white glove visual test can obtain comparable results to current dust-lead clea rance protocols based on results of wipe sampling. The approach of the white glove test is that the electrostatic or wet cloth must be essentially fre e of visible dust after sampling in order to pass cleara nce. In this way

, the new white glove protocol might function as a simple, quick and inexpensive approa ch for clearance testi ng. 2.0 B ACK GR OUND This report primarily pre sents the results from limited field testing with a potential new clearance protocol that EPA is calling the disposable c leaning cloth/white glove (DCC/WG) cleara nce prot ocol. How ever, th

is repor t also pre sents the

results of other pilot studies EPA conducte d leading

up to the c

urrent f ield study . These prior res ults are s ummarized

later in Section 2, as well a s the appe ndices of this report. Section 2.1 discu sses EPA’ s purpose in performing this field study , while Section 2.2 provides background on current c learance testing and defines the alternative DCC/WG clearance pr otocol. Section 2.3 summarizes the earlier pilot results f rom studie s of white

glove c learance testin

g using various d isposable cleanin g cloth protocol s. Section s 3 throug h 7 provide

the deta iled resu lts from th e curre

nt DCC/WG fie ld testing study . Section 3 present s the study design, while Sections 4 and 5 descri be the fi eld sampling and laboratory

analysis protocols. Section 6 prese nts the study results, as well as the interpretation of the data relative to the study objectives. Section 7 provides discussion and conclusions based on the study re sults. Section 8 summarizes the key inputs from a peer r eview panel tha t evalua ted the stu

dy. Section 9 a

ddresse s Quality

Assurance. The

Appendic es A through E present supporting material in the form of quality assurance

project plans and previous pilot study

reports . Appendi

x F contain s the wipe

sample da

ta for the field stud

y. A ppendix G is a p ic tu re ga ll er y of

th e f lo or s s am pl ed du ri ng th e s tu dy.
2.1 E PA Purpose EPA currently is deve loping technical guidance to help pre vent potential lead poisoning of household residents resulting from residential renovation and r emodeling (R&R) activities. Evidenc e exists tha

t R&R work

activitie s may

releas e hazard

ous level s of lead

ed dust an

d debris into residential environments. In one study, R&R activities such as demolition, window replacement and surface pre paration were found to release lea ded dust onto horizontal surfaces at levels as high as 40,000 : g/ft2 or more ( see EPA’ s report on Le ad Exposur

e Associa ted with Ren ova ti on a nd R emo del in g Ac ti vi ti es: Env iro nm ent al F iel d S amp li ng S tu dy, V ol um e I: Technical Report, EPA 747-R-96-007, May , 1997). Effective cleanup and clea ning verification following any such R&R a

ctivity is essenti al for pr

otection of househ

old occup ants, esp ecially you ng child ren, who are oft en most hig

hly exposed an

d most vulne

rable to the adve rse hea lth effects of lead.Final Report 2 Decem ber 28, 2005

Cleanup methods commonly used by R&R professionals (e.g., broom sweeping and vac uum cle anu p) c an s om eti mes be i nef fec ti ve i n re duc in g le ad d ust lo adi ngs to saf e le vel s. In limited testing, EPA concluded that residual lead levels after R&R activities followed by broom or vacuum cleanup could often be well over 100 : g/ft2 on floors (see EPA report 747-R-96-007, May, 1997). A fa st, inexpensive and reliable method for assessing post-R&R cleanup is an important component of EPA’s formulation of R&R guidance. To be e ffective, a clearance proto col ne eds to meet s everal crite ria, i nclud ing:

• provide quick feedback,

• be rela

tively inexpensiv e and ea sy t

o conduc t,

• possess good predictive accurac y conce rning surface lead loading s, and

• be compli ant with EP A regu lations.
It is envisioned that some R&R work and clea nup will be conducted by home owners themselve s and var

ious contr actors ( e.g., p ainters, carpen ters) who do not ne cessar ily f all within the jurisd iction of e

xisting EPA , HUD or o ther fe deral r egulat ions. The se individ

uals may also have limited training and familiarity with existing best practices for lead hazard reduction and lead poisoning prevention. Therefore, it is important that EPA’s R&R re gulations, guidance and associa ted proto cols and methods ar e intuitive , relativ ely

easy to impleme

nt, and at the same time accura te and ef fective for their intended purposes . The R&R

cleara nce prot ocol is one

of these important elements of EPA’s R&

R progr am.
2.2 Hi s to r

y a n d Mo ti va

ti o n fo r D e ve l o p m e n t o

f Wh i te G l o

ve C l e a r a n c e Tes t wi th Disposable Cle aning Clot hs
The cl earance testi ng meth od cur rentl y used in a batem ent or lead h azard contr ol set tings relies on ASTM dust wipe sampling. The objective of cleara nce testing is to verify

that cleanup has reduced lead to safe levels below the a pplicable EPA standards (see 66 FR 1206, January 5, 2001). Clearance testing requires that a dust collection technician take single wipe samples from the floor, window sill, and window trough in areas where lead hazard control work and cleanup activities have been performed. Dust wipe samples using wipes that meet the ASTM criteria are sent to an accredited laboratory r

ecognized by

EPA/NLLA

P for analysis. I f the lead measured in any of the wipes indicates a lead loading gre ater than or equal to EPA’s clearance standards (i.e., 40 μg/ft 2 on floors, 250 μg/ft 2 on sills, and 400 μg/ft 2 in troughs), the cleanup is declared to have failed and the cleanup and clearance sa mpling process is repeated until acceptable w ipe measurements are reache d for all s ampled su rface s. Because of the larg e number of R&R projects performed in the country , there are potential cost and scheduling concerns associate d with the idea of applying standard abatement or lead hazard control cle arance testing in a resid ential R&R environ

ment. As su

ch, EPA decided to investigate whether a white g love protocol performed with disposable cleaning c loths might be use ful fo r cond uctin g cleara nce tes ting i n an R&R setti ng.Final Report 3 Decem ber 28, 2005

2.2.1 De script ion of

t he Protoc ol EPA has developed an alternative method for lead c learance testing to verify the efficacy of clea nup afte r R&R pro

jects. Th is clear ance me thod does n

ot requir e wipe sa mpling to determine if lead loadings after cle anup are acceptable. I nstead, the new clearance sampling method uses disposable cleaning cloths (DCCs) as cleara nce testing tools. These commercial products are available as dry electrostatic cloths (e.g., Swiffer®, Gr ab-itTM) or as wet mopping pads that function with the aid of a detergent (e .g., Swiffer®WetJet®, Clorox®Ready Mop®). Dry and we

t DCC products come in different sizes and shapes, but all involve mopping with a dust colle ction dev

ice. Bo th dry

electro static an

d wet DCCs w ere eva

luated in the curr ent field st ud y. The prop osed DCC/WG cleara nce prot ocol is re latively

simple to c onduct an

d intuitive ly easy to understand. It involves thoroughly (and uniformly) mopping the entire floor or window sill with a DCC. Next the used DCC is visually inspected. Ifthe cloth retains its pre-use, nearwhite appearance, the floor or window sill is judge d to pass clearance and no additional treatment or samplin

g is nec essary . (A comp arison photogra ph is provi ded which shows the great est amount of soiling which should be tolerated to still conclude a near-white a ppearance in the visual assessment.) If the DCC visually appears more soiled than the comparison photogra ph, mopp ing of t he ent ire fl oor (o r wind ow sil l ) is repeat ed wit h a new c loth . Afte r this mopp ing, the visua l test is re peated u sing the

replac ement cloth. This se quence of mopping

and visua

lly assessing the used cloths is repeated until a cloth retains its near-white appearance after be ing used to mop the surface. Fig ure 1 i s a f

lo w ch art di agr am d esc rib in g th e DC C/ whi te g lo ve c lea ran ce p rot oco l. It illustrates the sequence of steps taken to test each floor or w indow surface. In a

ddition to the central instructions regarding the mopping and comparison to visual standards described above, the figure provides other important steps for ac knowledging the limitations of when the protocol may be used. The se issues are discussed further below.
2.2.2 Pote nt ial I ssues w it h t he Protoc ol
In the new clear

ance testing protocol, DCCs fulfill two functions: (1) they provide an easy wa y to immediately

assess the lead clearance status of floors and window sills, and (2) they continue removing dust/lead that remains after the primar y cleanup. Eve

n when cleanup has failed to remove s ome dust ( and poten tially lead), t he DCC pro tocol has

the poten tial to fin ish the cleaning job. However, it must be emphasized that the DCC cleara nce protocol is not intended to replace or supplement the primary cleanup of the site. The DCC/white glove protocol is being evaluated as a tool for identify ing when cleanup has been ef fective. Clearly , the DCC does c ontinue to

remove r esidual le ad dust tha

t cleanu p may have miss ed, but thi s is viewed a s a bonus a

nd not a core function of the protocol

.Final Report 4 Decem ber 28, 2005 Figure 1. White Glove Clearan ce Testing Protocol in an R&R Env ironmentFinal Report 5 Decem ber 28, 2005

The implicit assumption with the white-glove test is that a near-white DCC (dry or wet) will prove

to be a re liable pr

edictor of succe ssful cle arance . In o ther wor ds, it is ass

umed that a used DCC with no visible dust will accurately indicate that lead loadings fall below the clearanc e standar d. Hazar dous lead loading s on floor s may

not produc e visible d

ust residu es, but it is hypothesized that a wet or dry DCC, when mopped over an entire floor, will capture, ac cumulate, and amplify the visual appe arance of low levels of lead dust. I n this way, lead dust that may have been invisible on floors may be come visually evident on the white c loth. Experience has shown that some floor or window surfaces a ccumulate a dried lay

er of strongly a dhering dirt/grime that only an intensive cleaning or scrubbing c an remove. It must be emphasized that in EPA’s evaluation of the DCC/WG protocol, sampling with the DCC was never intend ed to be used o n these chall enging surfaces. Th is is why, after comp letion of R &R work, the first que stion that m

ust be add

ressed c oncerns

the condi tion of the

floor or window sil l surface to be tested. Specifically, is the surface smooth and cleanable? A surface that has numerous cracks and crevices or a surface missing much of its finish will invariably be unsuitabl e for DCC c learance testin g as it wo uld not be c onsidere d smooth an d cleana ble. This kind of surface would require refinishing , replacement, or some other appropriate r emedial work.
2.3 S u m m a r

y o f P r i o r

Wo r k C o m p l e te d to

D a te EPA has been conducting technical studies relate d to the development of a white glove test for the past five years (beginning in 2001). A ce ntral question of concern is how effective disposable cleaning cloths are for sampling . That is, how well do these cloths pick up leaded dust? Early

in this wor

k, EPA con sidered

two prima

ry way s of eval

uating t his question. First, EPA evaluated how much leaded dust a DCC could be expected to pick up (i.e., collec t) from the total amount of dust available on a horizontal surface (i.e., floors or window sills) in a controlled laboratory se

tting. Second, EPA evaluated how likely it is that a DCC will pick up any residual leaded d ust that mig

ht be lef t on a hori zontal surf

ace af ter R&R c leanup, s o that the surfac e could subseque ntly be expect

ed to pass lead cle arance

testing . While thes e were two centr

al questions, EPA also considered related issues such as chemical a nalysis protocols for ana

lyzing DCCs for lead content, and the ability of sampling technicians to visually and accurately

determine when DCCs are free of leaded dust when a w hite glove condition has been reached. Leading up to the cur

rent field study, EPA conducted four other studies that each examined d

iffere nt aspects of the q

uestions li sted abov e. The r eports f rom these four stud ies, wh ic h a re pr ov id ed in Ap pe nd ic es B t hr ou gh E, co ve r t he fo ll ow in g t op ic s, re sp ec ti ve ly:

• Chemical analysis protocol for analyzing DCCs for lea

d content

• Coll ectio n effi ciency of A STM d ust wi pes an d DCC s in a c ontro lled r oom s etti ng, and acc uracy of visual assessme nts for jud

ging the amount o f leade d dust on a D CC.

• Efficacy

of DCCs for collecting leaded dust in a real-wor ld setting and reducing residual dust-lead to levels below clearance standardsFinal Report 6 Decem ber 28, 2005

• Efficacy

of different dry

and wet DCC white glove protocols for reducing a variety of leaded d ust loadin gs to lev els below

cleara nce stan dards.
In the progre ssion of th ese pilot s tudies, qu estions re lated to the DCCs wer e first investigated in controlled laboratory conditions, and then in limited real-world testing outside of the labor atory . The first two studi es focus ed on the a bility of an indi

vidual DCC t

o collec t a known amo

unt of lea ded dust f rom a smooth surfa

ce unde r relati vely ideal conditions. T

hose favorable conditions included reasonably low lead loadings and sampling from linoleum floors that were in good condition. The third and fourth pilot studies then presented incr easing challenges to the evolving DCC/WG protocol. I n the third study, sampling was c onducted in real building s that rep

resente d reside

ntial R&R s ettings

in some wa

ys, but also di ffere d from tho se R&R settings in other way s. And, in the fourth pilot study, the DCC/WG protocol was challen ged wit h highe r lead lo adings b ack unde r contro lled laboratory

condition s. In total, these preliminary studies indicated that a white glove DCC protocol had the potential to serve a useful role in the R&R progra m. However, the protocol had not y et been tested in the field, in real-world residential housing by dust sampling technicians. Therefore, the current field study

also was conducted to help fill this information gap. Results from the four prelimina ry studies a re brie fly summarize d in the fo llowing S ections 2 .3.1 throu gh 2.3.4 , while the design and results from the current field study are discussed in Sections 3 through 7.
2.3.1 Rou nd R

obin St udy As noted above, one question of central importance for the evaluation of the white glove protocol was that concerning the amount of ava ilable leaded dust on a horizontal surface that DCCs could be expected to collect. One direct way to evaluate this question (and the approach taken in the First Controlled Room Study - see Section 2.3.2 and A ppendix C) is to “spike” (i.e., apply in a controlled f

ashion) a known amount of leaded dust onto a clean horizontal surface , and then pick the dust ba

ck up with

a DCC and d

etermine how much d

ust is colle cted. However, in order to determine how much leaded dust the DCC collected, a c hemical analy sis protocol was needed to determine the lead content of a DCC. Such a labor atory protocol wa s the focus of the Ro un d R ob in St ud y. Early in 2001, EPA funded the development of a laboratory protocol for digesting and chemically a

nalyzing DCCs for lead c ontent. The protocol was developed by the University of Cincinnati and Battelle. Subsequently, B attelle conducted the Round Robin Study to assess the accurac y of the new proto col. T he pri mary obje ctive of thi s stu dy was to c onfir m wit h a high degree of confidence

that the recovery

rates associated with the DCC chemical analy sis protocol are within the 80-120% recovery range. An additional objective of the study was to examine possible nuisance factors affecting the lead recovery . Factors considered were the c loth brand or manufacturer, the amount of lead spiked on the cloth, the labor atory ty pe, and the analy

tical method of lead detection.Final Report 7 Decem ber 28, 2005

For the final study de sign, four laboratories (two commercial, NL LAP-accredited la

bs and two research-oriented labs) ana lyzed three re

plicates at each of four lead spike levels (bla nk, low, medium, a

nd high)on each

of three differe nt cloth br

ands (Pro ctor and

Gamble ® ’s SwifferTM, Vileda ® Exst aticTM , and P ledge ® Grab-ItTM). Eac h of the four laboratories was to digest and analyze 36 spiked DCCs. All the labs ag reed to digest the cloths according to the protocol set for th by Bat tel le. All fou r la bs w ere to con duc t Fl ame -AA ana lysi s of th e re sul ti ng d ige st ate s. In addition, the two re search laborat ories we re to con duct I CP-MS anal

ysi s on aliquo ts of the sa

me digesta tes. The r

esults fr om the Exsta

ticTM DCCs w ere excl

uded from the data

analy sis due to complications experienced by the laboratories when digesting these c loths. All other data were included in the fina

l results. The study data we

re analy zed with a statistical model to assess the probability that a lead recovery between 80-120% can be achieve d with different DCCs, laboratories, lead levels, and analytical instruments. I

n most cases, the digestion and analysis protocol was found to be feasible, and in some cases the protocol worked ver y well (i.e., ther

e was a high probability

that the recovery

would be between 80-120%). However, in the c ase of one ty pe of cloth (i.e., the ExstaticTM)digesti on was a s erious pr oblem, an d in other cases c ertain ty

pes of cl oths, laboratories, and/or analy tical instrumentation do not appear to assure lead recover y in the 80- 120% range with high probability . Overall, the research laborator ies were able to perform the protocol with gre ater suc cess tha

n the ran domly selecte d NLL

AP labora

tories; th e Grab- ItTM cloths y ielded r ecover ies in the 8 0-120% r

ange w ith highe r probab ility ; and the I

CP-MS analy tical inst rumenta tion y ielded r ecover ies in the 8 0-120% r

ange f or a broa der (es pecially lower) range of lead le

vels. The commercial labs, Swiffer cloths, and Flame- AA analysis we re ge ne ra ll y as so ci at ed wi th lo we r p ro ba bi li ti es of ac hi ev in g t he ta rg et ed 80 -1 20 % r ec ov er y.
2.3.2 First Cont rolled Room St udy
Knowing f

rom the Roun

d Robi n Stud y t hat it is fe asibl e to d

ige st and chem ical ly anal yz e some DCCs for lead content, EPA was next able to perform a study to directly assess the a

mount of leade d dust that

DCCs might

be expect

ed to pick up from a

horizonta

l surfac e. This assessme nt was pe rformed in the First Controlle d Room Study . The primary objectiv es of this study were to g auge the efficiency of disposable cloths when the dust was collected in a manner similar to standard clearance testing, and to a ssess the feasibility of utilizing a visual assessment to determine the amount of dust present on a DCC. Also, an additional objective of this study was to gauge the sampling e fficiency of standard wipes. Earlier work by EPA (see Laborator

y Eva lu ati on o f Du st and Dus t Lea d R eco ver ies for Sam pl ers and Vac uum Cl ean ers , Vo lu me I: Objectives, Methods, and Results, EPA 747-R-94-004A, March, 1995) sugg ested that the sampling efficiency

of wipes is about 60-65%. The basic approach of this study was to apply (i.e., “ spike”) a known amount of leaded dust onto a horizontal surface and then determine how much of the dust a DCC might be expected to pick up. The study desig n consisted of two replicates at each of two lead loa ding levels (40 : g/ft2 and 100 : g/ft2 ) using two wipe methods (standard ASTM wipes and one brand of ECC) from four sampling regions (1 ft 2 and 4 ft 2 for ASTM wipes; and 1 ft2 , 4 ft 2 , 24 ft 2 , andFinal Report 8 Decem ber 28, 2005

48 ft 2 for ECCs). ASTM wipe primary sa mples were taken from each 1 ft 2 section of the sampling regions, and two primary ECCs were taken, one right after the othe r, from each sampling region. I

n addition, following the primary samples, secondary

ASTM wipe samples were collected to assess the amount of any residual dust that might have been left after primar y sampling . All cloth s were d igeste d and ana

lyze d by Battell e’s laboratory

using I CP-MS. The results from the sampling study indicated that the efficiency of the DCCs was not statistica lly d iffere nt from the

efficie ncy of the ASTM wipes, w

hich cur rently are use d in regulations that establish hazard and clearanc e levels. The efficiency for both was found to be 65-70%. Thus, the DCCs worked as well as the current standar d wipes to collect settled dust in a controlled room setting. Analy sis of the lead collection efficiencies of the DCCs over the f our sampling region sizes (from 1 ft 2 to 48 ft 2 ) at the two lead loadings (40 : g/ft2 and 100 : g/ft2 ) revealed a small decline in efficienc y as the dust lead leve ls increased. However, this decline was not sta

tistically signific ant.
The basic study approac h for the visual as sessment was to deve lop photog raphic standards depicting different amounts of leade d dust, and then to ask several sampling technic ians to co mpare th e appea rance o f differ

ent rea l DCC sample s with the photogra phic standards. A total of 444 visual assessments of the amount of dust present on 45 ECCs were performed by

10 Battelle staff. The amounts of dust on the cloths varied from about 0 mg to 500 mg. For each ECC, each staff member visually examined the amount of dust prese nt and categorized the amount according to a set of 11 photographic standards (except for one technician who did not evaluate six blank cloths that he had helped prepare) . The true amount of dust on each ECC also was measured via chemical ana lysis of the ECCs (along with numeric al back-c alculati ons using

the known

lead con centra tion of the

standar d refer ence ma terial du st) after the visual assessments had been completed. Out of the 444 visual a ssessments, 212 ass ess men ts cor rec tl y sel ect ed t he a mo unt of d ust (i. e., th e co rre ct p hot ogr aph ic s tan dar d). In addition, 119 other visual assessments missed the correct amount of dust by just one photographic standard (approximately 50 mg of dust) on the high or low side. I n total, 331 of the 444 visual assessments (i.e., 75%) judged the correc t amount of dust on each DCC to within one photogr aphic sta ndard, or within a

bout 50 mg

of dust. Results from the First Controlled Room Study indicated that DCCs can pick up leade d dust from horizontal surfaces with the same collection efficiency (approximately 65-70%) a s standard ASTM dust wipes. Furthermore, DCCs can achieve this same collection efficiency for larger surfaces. I

n addition, visual assessment of DCCs appears to be a feasible tool for determining the amount of dust on a DCC, and hence, for dete rmining when DCC sampling has reached a white glove status (i.e., no sig nificant dust present on the DCC). It should be noted that the First Controlled Room Study only included testing of dry

electrostatic cloths; no wet disposable cleaning cloths were tested.Final Report 9 Decem ber 28, 2005

2.3.3 Pilot Field St udy in V aca nt B uildings Results from the Round Robin Study and First Controlled Room Study indicated the potential feasibility of utilizing DCCs to collect residual dust from horizontal surface s. Howeve r, both of these stu dies wer e conducted in con

trolled la borator y se ttings. T herefore, it was impor

tant for E PA to beg in to asse ss how wel l a white g love DCC pr

otocol mig

ht perform in real-world cond

itions. As a

first ste p in this ass essment, EPA condu cted the Pilot Field

Study in Vacant Buildings. By

necessity, this study

changed the focus of the DCC evaluation to ac count for uncontrolled, real-world conditions as opposed to the controlled, labora tory conditions of the first two s tudies. I

n partic ular, a d irect as sessment o f the amo unt of ava

ilable du st that is collected by a

DCC can not be made in real-world conditions because the pr e-existing amount of leaded d ust on the s ampling

surfac e is unknow

n. Also, pr

e-existing dust acc umulates n

aturally over time, rather than being spiked in a known amount by researchers. Theref

ore, the efficacy

of the DCC sampling protocol was evaluated by its ability to leave a horizontal surface suitably free of lead ed dus t so t hat th e surfa ce woul d pass lead cl earance testi ng. To make th

is assessment, EPA r

equired a larg e number

of avail able hor

izontal sur

faces i n a real-world setting where some a mount of leaded dust was present. While investigating severa l alter nativ e locat ions at whi ch to c onduc t thi s type of f ield w ork, E PA bec ame awa re of t wo lar ge vacant b uildings likely to contai n leaded dust. One

building was the Se

neca Ho tel in Columb

us, Ohio, and the other was the Armstrong Vocational School in Washington, D.C. B oth are older, established structures likely to c ontain leaded dust, and both were vacant with plans for renovat ion, so the

y w ere re adily

access ible for s ampling

teams. The general study

approach was to select a variety of horizontal surfaces, sample a portion of each sur face to determine the initi al dust lea d loading , apply

the DCC protocol until

a white glove condition was achieved, and then sample a portion of the surface to determine the residual dust-lead level and whether the surfa ce would pass clearance testing . Because both the Seneca Hotel and Armstrong School are r elatively larg e structures, a variety of floor and window sill surfaces constructed of different building mate rials were available for sampling. The experimental design at the Seneca Hotel included 65 sampling loc ations consisting of eight different uncarpeted, hard-f loor surface ty

pes; 52 low-pile, carpeted sampling locations; and 101 wooden window sill sampling locations. Sampling at the Armstrong School included 101 sampling location s consistin

g of thr ee diff erent un carpet ed, hard -floor su rface typ es. All sampling in both the

Seneca Hotel and

Armstron

g School was cond ucted wit h dry electro static cloths; no wet dispos able cle aning c loths wer e tested in these b

uildings

. The Seneca Hotel contained several f looring and window ty

pes that might reasonably be found in residential housing. However, the Seneca had been empty

for several months and was in a rela tively poor stat e of disr epair when testing

was per formed. This mean

t that the i

nitial, pre-testing lead levels were of ten high. Also, the existing dust was often quite thick and caked. Often the floors and window sills were heavily cracked, or boards and joints were sepa rated. Additionally, there wer

e a large number of rooms in the Senec a Hotel where low-pile carpeting had been laid down to cover flooring that was in poor c ondition.Final Report 10 Decem ber 28, 2005

Becau se of the se and other limitat ions, the Se

neca Ho tel resul

ts must be in

terpreted with caution. Howeve

r, there were se veral r elevant and inter esting f indings. Perhaps t

he most significant was that in a large number of cases (35 of 37 cases) where the DCC/WG protocol was applied to uncarpeted hard-floor are as that had pre-testing lead levels betwee n 40 : g/ft2 (i.e., the clearance standard) and 100 : g/ft2 , the lead level measured after the DCC/WG protocol was below 40 : g/ft2 (i.e., low enough to pass clearance testing). Although there is limited information about lead levels in an R&R setting where cle arance testing has failed (se e Section 6.3.2), the current study

suggests that when the pre-protoc ol lead levels are between 40 : g/ft2 and 100 : g/ft2 , the lead levels after performing the DCC/WG protocol would be below the clearance standard.
The Seneca Hotel results also were ana lyzed from the perspe ctive of false negative and false positive decision-making errors. I n this context, a false-negative decision error wa s defined as a situation where the DCC/WG protocol achieved a white glove condition (indicating that the surface would probably

pass clearance testing), but the post-protoc ol ASTM wipe sampling indicated that the lead level was still above 40 : g/ft2 (i.e., that the surface would not pass clearance testing). Considering potential decision errors in the other direction, a false-positive decision error w as defined as a si

tuation where the

DCC/WG proto col faile d to achie ve a white glove c ondition after eig

ht to ten mop

pings (i ndicatin g that th e surfa

ce would probably fail clearance testing), but the post-protocol ASTM wipe sa mpling indicated that the lead level was actually below 40 : g/ft2 (i.e., the surface would pass clearance testing). When examining all of the Seneca Hotel uncarpeted hard- floor results, a false-negative de cision error rate of approximately 30% was indicated ( 31 of 93 cases) and a false-positive decision er ror rate of about 40%

was foun d. These error r ates inc lude a ra

nge of pre-pr otocol le ad level s (from le ss than 40 : g/ft2 to well over 1000 : g/ft2 ) and a range of floor mate rials (e.g., wood, linoleum and ceramic tile, marble and concrete)

. The Seneca Hotel Study

also provided an opportunity to collec t similar DCC testing informat ion from w

indow sills . In total, 101 window sills were te sted with 9 3 of the si lls achieving a white glove condition. I n a large number of case s (18 of 20 cases) where the DCC/WG protocol was applied to window sills that had pre-testing lead levels between 250 : g/ft2 (i.e., the clearance standard) and 500 : g/ft2 , the lead level measured after the protoc ol was below 250 : g/ft2 (i.e., low enough to pass clearance ). Similar to the floor results discussed earlier, these are cases w

here the DCC/WG protocol took pre-existing lead levels as high as twice the clearance standard a nd pushed them after the protocol to levels below the cleara nce standard. In terms of fa

lse-negative and false-positive dec ision error rates for the Seneca Hotel window sills, the results indicated a false negative err or rate of approximately

20% (16 out of 93 cases)and a fa

lse positiv e error

rate of about 75%

(6 out of 8 cases) . Note tha t the hig h false positive rate is based on very limited information.Final Report 11 Decem ber 28, 2005

Pilot field testing of the DCC protocol also was conducted in the Armstrong Voca tional School in Wa shington , D.C. How ever, in this case , althoug

h initial in spection

of the pr operty indicated that it was suitably repr esentative of residential R&R conditions, the subsequent detailed sampling and field work indicated that it probably was not an accurate surrog ate for these residential conditions. Although large floor surf aces with leaded dust were available, the dust was commonly much g reasier and more heavily

caked than one would expect in a residential setting after R&R work and the subsequent cle anup have been completed. I n addition, the percentage of pre- testing lead levels between 100 : g/ft2 and 1000 : g/ft2 was much higher in the Armstron g School than in the

Seneca Hotel. Despite t hese limit ations, th e results

from the A

rmstrong School ha

ve been included in Appe ndix D b eca

use they may prov ide inform ation

abou t the p erformance of

the D CC/WG protocol under es pecially challen ging c onditions. In c ases whe re the pr otocol wa s applied

to uncarpeted hard-floor surfac es that had pre-testing lead levels betwee n 40 : g/ft2 and 100 : g/ft2 , post-protocol lead levels below 40 : g/ft2 were achieved in a majority of cases (15 of 22 cases). In terms of false-ne gative and false-positive decision error rates for Armstrong School hard-floor surfac es, the r

esults indi cated a

false-negativ e error

rate of 67% (8 out

of 12 cas es), and

a false positive e rror ra te of 30% (55 out of

186 case s). I

n addition , becau se of the greasy a nd heavil y soiled floor conditions, there were relatively few cases where a white g love condition could be achieve d at all. Out of a tota l of 198 ca ses, the w

hite glo ve condit

ion afte r multiple DCC moppings was only a

chieved in 12 cases (i.e., less than 10% of the time).
2.3.4 Sec ond Cont rolled Room St udy Building upon the la

borator y a nd field e xperienc es of the

three e arlier s tudies, EPA decided to conduct a Second Controlled Room Study that pr imarily investigate d the ability of the DCC/WG protocol to handle elevated pre-testing dust lead loadings. B oth the First Controlled Room Study

and the Pil ot Field St

udy in Vaca nt Buildin

gs sug gested

that the protocol c ould achieve good success on hard- floor surfaces in cases where the pre-testing dust-lead levels are between 40 : g/ft2 (i.e., the clearance standard) and 100 : g/ft2 . However, the Study in Va cant Buildings suggested that the protocol wa s less successful at handling cases where the pre-testing lead levels are above 100 : g/ft2 . But, these results were collected in vaca nt commercial building s rather

than res idential R

&R settin gs. The refore , the dec ision was made to inv estiga te the hi gher lea d load ings b ack in a cont rolle d room setti ng. The study took place in a controlled room setting at Battelle in which each of three different 24 ft

2 floor surface areas, following initial cleaning, was “spiked” with a known amount of leade d dust (usi

ng two di ffere

nt standa rd refe rence material s; SRM #2584 = house dus t with 1% lead, SRM #2589 = p ulverized paint with

10% lead

), subseq uently mopped wi

th disposa

ble cleanin g cloths , and then

subjecte d to wipe sa

mpling. T he wipe s amples we

re chem ically digeste d and ana

lyze d for lea

d content . The re sults of the laborat ory analy sis were used to estimate the amount of lead remaining on the floor following the protocol.Final Report 12 Decem ber 28, 2005

Under th e base pr

otocol, a series o f dry

electro static cl oths was u sed within the sample area to collect t he dust le ad until a

clean c loth was a

chieved after w iping the area ( i.e., whi

te glove). Determination of this white glove condition was done by visual comparison to a photographic standard. After white glove was achieved, four ASTM wipe samples were collected from randomly

selected 1 ft

2 sections within the area, as well as from two random 1 ft 2 areas on the perimeter of the sample re gion. Four lead loadings (40, 200, 600, and 1,600 : g/ft2 ) were examined for each of two differ ent standard reference mate rials. Each combination of lead loading and stand

ard ref erence materia l was exami

ned for e ach of the three

floor sa mple are as. Testing was completed over 10 day s in October, 2003. In every testing sequence of the Second Controlled Room Study , the DCC/WG protocol was continued until a white glove condition was achieved. The refore, when interpreting the results the conclusions are necessarily limited to the protocol’s ability to take pre-e xisting lead levels that are well above the cleara nce standard and push them to levels below the cleara nce standard. Along with this, an assessment can be made about the f alse-negative decision error rate. However, no assessment of the false- positive error rate was possible in this study because a white glove condition was achieved in every case. In addition, beca

use some experience in the previous studies indicated that several iterations with the DCCs might be required in some ca ses to achieve the white glove condition, the Second Controlled Room Study also considered three potentia l variati ons of the

protocol in hopes that they

might ac hieve the white g love cond

ition in fewer m oppings

. The results with the base DCC/WG protocol indicated good success when the pr e-testing lead levels were either 40 : g/ft2 or 200 : g/ft2 . In these cas es, 47 of 4 8 tests re sulted in p osttesting lead levels below 40 : g/ft2 , implying a fa lse-negative error ra

te of about 2% (i.e., 1 out of 48 cases). At higher lead levels, the r esults showed higher false-neg ative rates. When the pretesting lead level was 600 : g/ft2 , 15 of 24 tests resulted in post-testing lead levels below 40 : g/ft2 – a false-negative err

or rate of about 40% (i.e., 9 of 24 cases). A nd, when the pre-testing lead level was 1600 : g/ft2 , only 4 of 24 tests resulted in a post-testing lead level below the clearance standard – indicating a false-neg ative error rate of more than 80% ( i.e., 20 of 24 cases). Supplemental testing with the three variations of the basic DCC/WG protocol was run at the highest lead level of 1600 : g/ft2 to investigate whether improvements in the false-neg ative error r ate coul d be ach

ieved. T he first protocol v ariation consiste d of perf

orming t he base DCC/WG protocol, and then after a white glove decision had bee n made, performing additional moppings with two mor

e dry DCCs. This f

irst proto col vari ation led to some impr

ovements with 17 of 24 cases resulting in post-testing lead levels below the clearance standard – a fa lse-negative error rate of about 30% (i.e., 7 of 24 c ases). The second protocol variation included every thing from the first protocol variation (i.e., perfor m the base

protocol , then two

more dry DCC mopping s) plus one additiona l mopping

with a wet ECC at the end. With this second protocol variation, all 12 tests that were performed resulted in post-testing lead levels below the cleara nce standard – that is, a 0% false-neg ative error rate.Final Report 13 Decem ber 28, 2005

The third protocol variation included a somewhat simplified approach fr om the first two. Namely, the ba sic DCC/WG protocol was performed until a white glove decision was made, a nd then one additional mopping was performed with a wet ECC at the end. T his third protocol variation resulted in 11 of 12 cases where the post-testing lead level was below the clearanc e standard – indicating a false-neg ative error rate of about 10% (i.e., 1 out of 12)

. In all cases, the conc entration and form of lead in dust was not found to be a significa nt covaria te in explai

ning re sults. Overall, results from the Second Controlled Room Study indicate d that reasonably good results can be expected (at least under controlled conditions) with the basic testing protocol that employs dry

DCCs when the pre-testing lead levels are a s high as 200 : g/ft2 . In addition, including a wet sampling cloth after the basic dry DCC protocol may

provide a reasonable means of handling even higher pre -testing lead levels, with levels up to 1600 : g/ft2 being in vestiga ted in th is st ud y.Final Report 14 Decem ber 28, 2005

3.0 ST UD Y DESIGN Following the work detailed in Section 2.3, the present field study was performed with a primary objective of evaluating the real-world ef ficacy of a white glove clearanc e protocol using disposable cleaning cloths. I n simple terms, if disposable cleaning cloths remain near-w hite after application to a surface, can we re liably conclude that lea d loadings are at or below the clear ance standard? If the effectivene ss can be empirically validated, then this protocol might prove a legitima te option f

or clea rance s ampling

in an R&R e

nvironme nt. The study desig

n and results sections in this report will refer to a Disposable Cleaning Cloth/White Glove cle arance protocol . This will b e abbre viated a s DCC/WG cle arance protocol

. The DCC/WG c learance proto col is a g eneral term that refer s to the set of activ

ities per formed in determining whether or not a surfac e wiped with cleaning cloths achieves white g love, and hence meets clearance standards. This idea wa s presented and discussed in Section 2.2 and was depicted graphically

in Figure 1. Several important points apply to the DCC/WG clearance pr ot oc ol us ed in th is fi el d s tu dy:

• The protocol used in this evaluation is similar to what was done in previous studies but not ide

ntical. T o underst

and the sp ecific d

etails of the proto col execu

tion for th

is study, refer

to Sections 3.2 and 3.3. See the appropriate appendices for r eferences as to how the

protocol was per formed in previous studies.

• The studies previously done f or this protocol used mostly dry electrostatic cleaning cloths (also called ECCs or ECs). However, it was discovered that the protoc ol might be most effective when employ ing cleaning cloths that included a liquid deterg ent rather than just E CCs. To ref

lect this broader

population of poten

tial clea ning clo ths, the term “ ECC” has b een rep laced with the mor e gene ric “DCC” , for disp osable cleanin g cloth. The two ty

pes of cl othes ar

e disting uished by calling them a we

t DCC or a dry DCC.

• To assess the impact of the critical question of protocol effec tiveness as a function of the type of cle aning cloth used, a design was cr eated that tested implementation of the same bas ic protoc ol but with d iffere nt disposa

ble clea ning clo th config

urations , both dry and we

t. Commonly referre d to throughout the following report as “trea tments”, they include:

• Dry DCC/WG cleara

nce protocol (Max 15 cloths) on floors - Also known as the dry trea tment or dry protocol, this version of the pr otocol used only dry (electrostatic) cloths attached to their appropria te manufacturers’ mop heads. For time and cost reasons, if 15 cloths were used without reaching white glove, the protocol was stopped and the surface cate gorized as ‘failed to reach white glove’.Final Report 15 Decem ber 28, 2005 • Dry+1 Wet DCC/WG cleara nce protocol (Max 15 dry D CCs) on floors - Also known as the dry+ 1 wet treatment, this refers to the protocol that is the same as the dry protocol e

xcept that one additional pass is made of the floor surface using a wet DCC after the dry

treatment is complete.

• Wet DCC/WG clearance protocol (Max 15 Cloths) on floors - Also known as the wet treatment, this refers to the protocol using exclusively disposable wet cleaning cloths attached to their appropriate manufacture rs’ mop heads. The protocol was stopped if white g love coul d not be ac hieved in 15 cloths.

• Dry DCC/WG clea

rance p rotocol ( Max 3 Cloths)on sills

- Also known as the dry treatment or dry

protocol, this version of the protocol used only dr y (elec trostatic) cloths. Wipi

ng was d one by hand for sills. The

protocol was stopp ed if whit

e glove c ould not be

achieve d in three

cloths.

• Wet DCC/WG cl earanc e protoc ol (Max 3 cloths) on sill s - Also known as the wet treatment, this refers to the protocol using exclusively disposable wet cleaning cloths. Wipi

ng was d one by hand for sills. The protocol was stopp ed if whit

e glove c ould not be

achieve d in three

cloths. Note: the small sample surfaces of sills did not permit the evaluation of the dry +1 wet treatme nt, as wa s done on f

loors. The following sections describe the data quality objectives of the study (Sec tion 3.1), compare the DCC/WG clearance protocol for g eneral application to that used in this field study (Section 3.2), discuss the implemented study desig n (Section 3.3), and identify importa nt departures from the Quality Assurance Project Plan (Section 3.4).
3.1 St udy Dat a Qual ity Obj ect ives Four data quality

objectives (DQOs) have been identified for this study . These represent specific and measurable way s to evaluate the general hy pothesis of the study. There are three DQOs ass ociated

with a cor

e assumpt ion that the

DCC/WG clea

rance p rotocol a chieves a “passing” condition, and one DQO for ca ses where this does not happen (i.e., white glove is not achieved).
1. How does a DCC/WG clearance protocol “pass” r esult compare to a formal wipe cl ea ra nc e s am ple re sul t?

a. The primary data

quality objective

of this stud

y w as to estimate the probabilit y (and corresponding 95 % lower c onfidence bound) that surfaces will achieve the wipe samp ling cle arance

standar ds, give n that the surfac es have p assed the white glove condition. Separate estimates were obtaine d for hard floors and window sills and f or each treatme nt applie d to these

two ty pes of sur faces.Final Report 16 Decem ber 28, 2005 b. An additional primary data quality objective

was to compa re the l ead lo adings before and after application of DCC/WG cleara nce protocols from the Second Controlled Room study results (as refer enced in Section 2.3.4) to the results from this study . If t

hey are fou nd to be sim

ilar, re sults from

the two stu

dies coul d complement each other and provide a strong er conclusion regarding efficacy of the protocol(s).

c. A secondary

data quality objective

was to ev aluate w

hether a nd how ce

rtain covariates impact the results. Covariates of interest include the spe cific nature of the protocol (e.g., whether dry DCC, wet DCC, or both), the initial dust-lead level before application of the protocol, the surface area where the protocol was applied, the type of sur

face material (e.g., ha

rdwood, linoleum, painted concrete, ceramic tile), and the condition of the surface (e.g., cleanliness, wear).
2. How does a DCC/WG clearance protocol “fail to ac hieve white glove” result compare to a forma

l wipe cle arance

sample re sult?

a. Under certain conditions (e.g., ca ked on grease/grime or

chipping paint), the protocol did not always ac hieve white glove within the maximum number of cloths pe rmitted. F or such c ases enc ountere d in this stud y, a separa te estima te was made of the probability that a wipe sample would result in a pass even when the clea ning/cl earanc e protoc ol fails to achieve a white glove cond

ition. This particular estimate was designated as a secondary data quality objective

. 3.2 DC C/ W G Clea rance Pro t ocol as Im plement ed in t he Field St udy Figure 2 depicts the data collection protocol e mployed in this field study overlaid on the envisioned implementation of a real-world protocol (as was illustrated in Fig ure 1). Those steps in Figure 1 that are not included in the field study data collection protocol are indicated by dashed connecting lines and the text boxes are cross-hatche d with reverse color text (white on dark). The additional steps in Figure 2 that do not apply to a real-world application, but were needed to collect the data for this study , are shown as text boxes with gray (rather than white) backg rounds. T

he 15 clot h limit shown

in the lowe

r right diamond of

the fig ure is als o gray

ed to reflect the fact that this n

umber wa s selecte d specif ically for the f ield study . A diffe

rent cr iteria may well apply

to an implemented real-world protocol. The implemented study, as shown in F igure 2, differed in some important way s from the envisioned application of the protocol in real-world settings (see Figure 1). These differ

ences included:Final Report 17 Decem ber 28, 2005

Figure 2

. W hit e Glov e Cle aranc e T est ing P rot ocol f or Field St udy in Resident ial H ousingFinal Report 18 Decem ber 28, 2005

• For the field study, two f loors were selected at each fie ld site that best met the desired “smooth and cleanable” criteria that might a pply to a real-world application of the protocol . Howeve

r, condit ions at some

sites wer e so poor t

hat two ad

equatel y smooth and cleanable surfaces we re not available and the study had to settle with selecting floors that came closest to meeting the desired cr iteria. In part, this was nece ssitated by the supply

of residential housing units where the study could be performed. However, it ultimately ser ved the additional purpose of providing insight into what might eventually c onstitute a definition of a surface that is not “smooth and cleanable.” For instance, spec ific exclusionary floor (or sill) conditions might include: large

surfac e area s without f

inish, fre quent and

large cracks or crev ices, protuber ances ( e.g., s taples, s

plinters) , and a la

ye r of acc umulated grime/d irt.

• A thorough site cleanup (that ty pically would be conduc

ted after R&R but before clearance) was intentionally not included in the field testing protocol. Rather, a perfunctory

broom sweeping was conducted befor e any da ta collection commenced. The objective of only

broom sweeping was to increase the c hances of having lead levels above the clearance standa rds before beginning the protoc ol. This permitted evaluation of two important concerns about the DCC/WG clearance pr otocol; (1) Would it ever achieve white glove when the surfa ce lead levels exceed the cleara nce standard? and (2) Can it successfully identify (by passing

the white glove criteria) that the lead loading was below the cle arance

standar d when the

DCCs are t

he vehic le through which the lead reduction occurr ed? To get the results of this evaluation, the DCC s we re e val uat ed a fte r a l ess in ten si ve c lea ni ng t han mi ght typi cal ly be don e. In the real world, a dirty

DCC would demonstrate that primary c leaning had been inadequate and this would trigger a c omplete recleaning effort for the entire room. For the f ield study , this was n

ot the ca se. Reg ardless

of how “d

irty ” the use d cloth was, a fresh DCC was instituted, up to an operational limit of 15 DCCs for floors and 3 for sills. This extended use of DCCs would be impractical and inefficient in actual practice.

• To quantitatively assess the ef ficacy of the protocol, an objective measurement was needed for lead measurement bef ore and after performanc e of the protocol. The experimental design specifies that ASTM wipe samples be collected both bef ore and after DCC clearance testing. To minimize the inaccur acies introduced in measuring overall floor lead loading with a 1 ft 2 wipe sample, the experimental design provided for two sp atially

separa ted sample s on each

floor sur face a t each time point. These two measurements were averag ed to determine the lead loading before and after application of the protocol. For sills, a single pre and post-protoc ol wipe sample were adequate because of the much smaller sur face areas involved.Final Report 19 Decem ber 28, 2005

3.3 Im plement ed Field St udy

The implemented field study in re sidential housing comprised three important componen

ts:
1. The locations - Locations wer e selected which might reasonably be expected to have leaded dust from some renovation and remodeling wor k but primarily from lead hazard control work . Additional information on the procedure for identific ation and qualification of potential study locations is provided in Section 4.1, Site Selection.
2. The people - The field study protocol was generally

performed by

two sampling technicians at each site. I

n Baltimore, the sampling technicians were e mployees of Leadtec Service s, Inc. or Healthy Housing Solutions, Inc. I n Milwaukee, the sampling technic ians wer

e staff o f the Milw aukee H ealth De partmen t. All technicians were certified in clea rance wipe sampling. The majority were experienced lead risk assessors. Technicians followed the experimental protocol as defined in the Quality Assur ance Project Plan (see Appendix A). On-site training wa s provided for all sa mpling te chnicia

ns.
3. The protocol - A DCC/WG clearance protocol was per formed on window sills and floors a t the resi dences w

ith dust wip e clear

ance sa mpling be fore an

d after to de te rm in e p ro to co l e ff

ic ac y. A summari zed and sim

plified ve rsion of the study

protocol is as follows:
1. Identify

two suitable rooms (designated Room A and Room B) within the housing unit. In each chosen room, ther e should be evidence that lead hazard control, lead abateme nt, or R&R

-ty pe work was comple

ted, and t hat lead ed dust mig

ht reasonably be expect ed on the f

loors and window sil ls.
2. In each selec

ted room, identify, measur e, and, using masking tape, partition the floor area in to two approximately

equal te st area s. (The d

ry DCC and dr

y/w et DCC protocol was tested in one area; the wet DCC protocol was tested in the other half.)
3. Ide ntify one window sill are a in each room and partition this sill into

two roug hly equal areas using masking tape

. 4. In Room A, for the window s ill: a. Sweep an

y la rge de bris from the sill. b. Collect a

n ASTM wipe

sample on

one half of the sill

. c. Measure the associated dimensions of the sill to determine the area represented by the wipe sample.Final Report 20 Decem ber 28, 2005 d. Successi

vely wipe dry DCCs over

the other side of th e sill until t

he used D CC appears as clean as the ref erence white glove visual standard or until a maximum number of DCCs (three) have been soiled. e. Once achieving white glove (or the final limit cloth), perform a clearance wipe sample on this same side of the sill, once again measuring the associated dimension s of the sil l. 5. In Room A, for the floor: a. Sweep any la

rge debris from the floor. b. On one half of the floor i. Randomly designa

te two, 1 ft 2 location s, and pe rform a c learance wipe

sample in each location. ii. Perform the dry

DCC/WG clearance protocol until a DCC mopped over the entire f loor surf ace is a s clean a s the appr opriate visual sta

ndard for white glove or until 15 cloths have been soiled without reaching this standard. iii. Adjacent to the first two sampling locations, without overlapping any other sample loc ations, ta

ke a sec ond set of

cleara nce wipe samples. iv. Wipe the e

ntire ha lf floor s urface with a sing

le, wet D CC.
v. Adjacent to the first and second sets of samples, without overlapping a ny other sample loc ations, ta

ke a fina l set of cl earanc e wipe sa

mples. c. On the other half of the floor i. Randomly designa

te two, 1 ft 2 location s, and pe rform a c learance wipe

sample in each location. ii. Perform the wet DCC/WG clearance protocol until a DCC mopped over the entire f loor surf ace is a s clean a s the appr opriate visual sta

ndard for white glove or until 15 cloths have been soiled without reaching this standard. iii. Adjacent to the first two sampling locations, without overlapping any other sample loc ations, ta

ke a sec ond set of

cleara nce wipe samples.
6. In Room B, for the wind

ow sill a. Perform exactly the same protocol as for Room A, but use disposable wet cloths in st ea d o f d ry. 7. In Room B, for the floor a. Perform exactly the same protocol as for Room A. The critical sampling and cleaning c loth activities are illustrated in Figure 3. Floor sampling is shown in t

he top dia gram a nd sill samp ling bel ow. Each process diagra m shows a progres sive v iew of

the st eps pe rform ed for e ach su rface fr om in itia l wip e samp ling, throu gh cloth mopping, and finally to post-pr otocol wipe sampling. At each step, the lege nd box under each sur face pi cture id

entifies the activ ity c ompleted

in that ste

p. Activit

ies prev iously completed are retained on the diag ram but are relegated to the ba ckground by

gray ing or dashed lines. In this way , the total protocol can be envisioned as a set of lay ers applied to a surface.Final Report 21 Decem ber 28, 2005 Figure 3

. P rocess Flow Dia gram of Sampling f or R esident ial Field St udy From the diagrams in Figure 3, it can be seen that the protocols can be evaluate d for effectiveness in the following manner:
For Floors a. By compa

ring the mean of the two wipe samples taken af ter the dry pr

otocol to the mean of the two wipe samples before the dry protocol began, we can eva luate the effec tiveness

of the Dr y D CC/WG clea

rance p rotocol. b. By compa

ring the mean of the two wipe samples after the dry protocol with one additional wet DCC, to the mean of the two wipe samples before dry protocol began,Final Report 22 Decem ber 28, 2005 we can e valuate the eff ectiveness of the

Dry + 1 Wet DCC/WG

cleara nce prot ocol. c. By compa

ring the mean of the two wipe samples after the wet protocol to the mean of the two wipe samples before the wet protocol beg an, we can evaluate the effec tiveness

of the Wet D CC/WG clea rance p rotocol.
For Sills a. By compa

ring the value for the wipe sample taken a fter the dry

protocol to the value of the wipe sample before the dry protocol began, we can eva luate the effectiveness of the Dry DCC/WG clea

rance p rotocol. b. By compa

ring the value for the wipe sample taken a fter the wet protocol to the value of the wip e sample

before the wet pr

otocol be gan, we

can eva luate the effec tiveness of the Wet D CC/WG clea rance p rotocol.
Note: No Dry

+ 1 Wet DCC/WG

cleara nce prot ocol was evaluat ed for window sills because the surf ace ar eas wer e insuff icient to i nclude th is third tr eatment. More specific details regarding selection of sampling locations, instructions for performing the clearanc e wipe sampling, instructions for execution of the protocols (including the appropriate visual standards), and required doc umentation of activities is provided in the Quality Assurance

Project Plan (see Appendix A).
3.4 QA PP

M odif icat ions The following table details the deviations from the Quality Assurance Project Plan (see Appendix A) . For co mpletene ss, ever y kn own devia

tion has be en includ

ed. Howe

ver, it should be noted that most of these deviations resulted from normal operational limitations that can be expected in a field study of this ty pe. The number and nature of the deviations wer e not judged to threa ten the a ccurac y or validity of the stu

dy r esults.
Sampling U nit Exception to QAPjP Pilot (Unit 00) For Floor A, the condition of the half of the floor desig nated for the wet treatme nt was de emed too p oor to per mit completion of the

protocol

. Hence, pre-protocol wipe samples wer e taken but the protocol was not completed, no post-protocol wipe samples were taken, and this half of the fl oo r s ur fa ce wa s e li mi na te d f ro m t he st ud y. 01 For Floor B, the sampling staff r an out of time to do the half of the floor surface slated to get the wet trea tment, so this half of the floor surface was el im in at ed fr om th e s tu dy.Sampling U nit Exception to QAPjP

Final Report 23 Decem ber 28, 2005 03 The two “

halves” of Floor B are a ctually two very small adja

cent rooms in the unit. Additionally, in each of these spaces, the accumulation of signific ant drie d “mounds” or “cak ed-on” d ebris re quired more than j ust a broom sweep before application of the protocol. I n each case, debris was first scraped from the floor surface before the broom sweep. 05 The sill with the wet treatment was recorded as fa iling to reach white glove after two DCCs thoug

h this conc lusion shou

ld not have

been re ached u

ntil three DCCs had failed the visual inspection for white glove. 11 The wipe samples from this site were found to be mislabeled during

execution of the protocol. The measurements for this unit have been excluded f

rom the stu

dy r esults. 12 The si ll wi th th e wet t reatm ent rea ched wh ite gl ove in six DCCs , tho ugh

the treatment was supposed to be stopped and concluded as a w hite glove failure after three DCCs failing the visual standa rd for white glove. 20 The sill wi

th the wet treatme nt failed to reach white g love in six DCC s, though the treatment was su pposed to b e stopped

and conc luded as a

white glove f ailure after thr

ee DCCs ha

d failed the visua l standar d for whit e glove. 23 The sill wi

th the dry treatme nt failed to reach white g love in six DCC s, though the treatment was su pposed to b e stopped

and conc luded as a

white glove f ailure after thr

ee DCCs ha

d failed the visua l standar d for whit e glove. 25 The sill wi

th the wet treatme nt failed to reach white g love in six DCC s, though the treatment was su pposed to b e stopped

and conc luded as a

white glove f ailure after thr

ee DCCs ha

d failed the visua l standar d for whit e glove. 26 The sill wi

th the wet treatme nt failed to reach white g love in six DCC s, though the treatment was su pposed to b e stopped

and conc luded as a

white glove f ailure after thr

ee DCCs ha

d failed the visua l standar d for whit e glove. 27 The si ll wi th th e wet t reatm ent rea ched wh ite gl ove in six DCCs , tho ugh

the treatment was supposed to be stopped and concluded as a w hite glove failure after three DCCs failing the visual standa rd for white glove.Sampling U nit Exception to QAPjP

Final Report 24 Decem ber 28, 2005 28 No Floor A or Sill protocols were done in this unit. The Floor B protocol

consiste d of the Wet Only treatme nt on both ha

lves of th e floor; one with the mop ma

nufactu rer’s c leaning

solution a

nd one wit

h only water a s a cleaning solution in the mop. Additionally, sampling where white glove could not be achieved was limited to five cloths instead of the 15 required in the QAPj P. 29 Floor A had the Dry +1Wet protocol applied to both halves of the floor. The one wet cloth used the mop manufacturer’s c leaning solution on one half of the floor. The one w et cloth o n the othe r side of the floor used only water a s a clea

ning solu tion in the m

op. Floor B had the

Wet Only protocol applied to both halves of the floor. The mop manufacturer’ s cleaning solution was used on one half of the floor and only water was used as a cleaning solution in the mop on the other half of the floor. The side of th e floor w

ith only water f ailed to r each wh ite glov e in 14 DCCs , though the protocol should have used 15 cloths before rea ching that conclusion. 30 Floor A had the Dry +1Wet protocol applied to both halves of the floor. The one wet cloth used the mop manufacturer’s c leaning solution on one half of the floor. The one w et cloth o n the othe r side of the floor used only water a s a clea

ning solu tion in the m

op. Floor B had the

Wet Only protocol applied to both halves of the floor. The mop manufacturer’ s cleaning solution was used on one half of the floor and only water was used as a cleaning solution in the mop on the other half of the floor.Final Report 25 Decem ber 28, 2005

4.0 F IE L D DA TA COL L E CTI ON Field data collection was performed in Ba ltimore and Milwaukee from July to Dece mber 2004. A tot

al of 31 ho

using un its are in cluded in the study results, 1 1 in Balti

more and 20 in Milwauke e. The pr

ocess for identif

yin g and qu alify ing pote ntial samp le locati ons is expla ined in Section 4.1. The locations, dates, and sample conditions for each unit are pr ovided in Section 4.2.
4.1 Sit e Se lect ion The obje ctive of

the study was to ide

ntify real-world res idential housing that could provide an opportunity to assess the e ffectiveness of the protocol in determining if cle arance had been met . The sele ction of these units was rest ricted b y th e followi

ng factors:

• Un it s w er e o bt ai ne d f ro m o wn er s w il li ng to vo lu nt ee r t he ir pr op er ty f or th e s tu dy. Study team members in Ba ltimore worked through the City of Baltimore’s Lea

d Progra m, as well

as priva te owners, to ident

ify units wher

e the sam pling te am would be allowed to complete the protocol. I n Milwaukee, the City Lead Program was the sampling team, tho ugh the y st ill had to obtain per

mission fr

om proper

ty owners to perfor m the study . Though

not strict ly a require ment, it tur

ned out to b e logist

ically easier to perform the protocol in uninhabited units. All sample units were unin habit ed at t he tim e of sam plin g.

• It was desired to include as many units as possible with expected, pre-protocol lead lev els abo ve t he c lea ran ce s tan dar d fo r re aso ns e xp lai ned in Sec ti on 3 .2. In Baltimore, selection of units with expected lead hazards was done subjectively , which resulted in some units that were sampled having very low lead contamination levels. In Mil waukee , risk ass essment sa mpling wa s used to id

entify and quali fy

units with floors over the clearance standa rd.

• Some surf

ace con ditions we

re known in advanc e of this st

udy to be unte

nable wit h the proposed experimental protocol; therefore, these conditions were used to screen potential sample locations. To the extent possible, surfaces were required to be “smooth and cleanable.” While this terminology could be interpreted in different ways, it was used in this study to exclude any surfac es that were in very poor condition (e.g. , crack

ing, spli ntering ) so that the protoc ol could no t be rea sonably implemented, because the DCCs would catch or tear apa rt on the surface imperfections. As discussed in Section 3.2, this still resulted in some testing for the field study of surfa

ces that would probably

not meet “smooth and cleanable” standards applicable to a genera l use of the protocol. Additionally, only hard surfaces were considered (e.g ., no carpeting). Other factors of floor condition were considered in this study and are discussed in more de tail in Section 6.3.Final Report 26 Decem ber 28, 2005

4.2 Sam pling L

ocat ions and Condit ions Tables 1 and 2 show detailed descriptions of the 31 units sampled. I n addition to the location and date, each table shows the size of the surfac e area, the surface mate rial, the surface condition, and what treatments were applied. The floor areas in this evaluation range d from 48 to 225 ft 2 . Since tw o separa te treat ments were completed on each floor (c ombined dry and dry +1wet or wet only

), the results reported for this study represent floor a reas ranging from a

pproximately 24 to 113 ft 2 . The majority of floor surfaces sampled were wood (72 %) . An additional 26% were linoleum or tile. In one location, concrete floors were sampled. Surfa ce conditions varied from very good (newly

installed or refinished wood floors with a poly urethane seal) to very

poor (rough surfaces, unfinished surfaces, cracked). Appe ndix G contains a gallery of digital photographs of the floor surfac es sampled. In this appendix, Floor A for Unit 01 is an example of a floor in good condition. and Floor A for Unit 03 is an example of a floor in poor condition. The protocol was applied to sill surfaces ranging from 0.4 to 2.4 ft 2 . Two sill surfaces were identified as ‘painted’ without designation to their under lying surfa

ce material. Otherwise, all other sills were recorded to be wood. Sill surface c onditions varied over the same range as floor conditions.
The Swiff

er® and S wiffer

® Wet® cloth s were u sed for a ll dry DCC and we

t DCC sampling, respectively , on window sills. For floors, the dry tr eatment was completed with the Swiffer® mop and corresponding dry , electrostatic cloths at all locations. The wet treatment (and the +1 wet cloth after the dry treatment) used two different systems; the Swiffer® WetJet® and the Clorox® ReadyMop®. These are commercially a

vailable mop handles with an attachment for a bottle of cleaning solution. Dry disposable cleaning pads are aff ixed to the rectangular mop head and a trig ger on

the mop spr

ay s a strea

m of clea ning solu tion ahea d of the mo

p head on to the floor. The spray

function is battery-ope

rated for the Swiffer® product and manual f or the Clorox® product. For Units 28-30, the treatments utilizing wet DCCs were modified slightly to obtain a compari son of the

protocol effec tiveness

with the ma

nufactu rer’s c leaning

solution to perfor mance with only

water a s the cle aning so lution. The results of this analy

sis are sh own in Section 6.2.3.4.Final Report 27 Decem ber 28, 2005 Table 1. F ield Study

Floor SamplingFinal Report 28 Decem ber 28, 2005 Table 2. F ield Study

Sill SamplingFinal Report 29 Decem ber 28, 2005

5.0 L AB OR ATOR Y ANAL YSIS All ASTM wipe sample preparation and analy sis was conducted by Mic robac Laboratorie s, Inc., Gasc oyne Division , an NL LAP- accre dited lab oratory . Details of the ap plicable analytical methods ar

e provided in Section 5.1. Descriptions of the laboratory QC results are provided in Section 5.2.
5.1 Review ofA naly t ical M et hods Sample analy sis was conducted u sing Fla me Atomic

Absorption Spectro

photometr

y in accordance with NI OSH method 7082. This method provided accurate measurement of lea d content to a lower quantitation limit of 10 : g per wipe sample. All dige states fr

om samples

were stored following analy sis in the e vent that EPA should desire a re-analy

sis of the samples (e.g., with an analy tical method providing a lower quantitation limit).
5.2 Labo rat ory QC R esult s QC sam ples f

or thi s stu dy includ ed the follo wing:
Field B lanks - F ield sampl ing staf f inserte d a singl e blank wipe into a n empty sample collecti on tube at

the conc lusion of s ampling activitie s at each unit and r eturned that sampl e with the other wipe samples. This sample was analy zed by the laboratory

with the expectation that the result would show no lead contamination. Table 3 shows that all field blanks with the exception of one were below the quantitation limit. The one exception was for Unit 08 which showed a measurement of 15 : g. This s ample was re-analy

zed in the lab with a similar result (17 : g). Review of the sample log y ielded no explanation for why

the field blank mig

ht have ha

d lead contaminati on. Conseq uently , the data for Unit 0 8 have be en left in the fina l statistic al analy

sis. Spiked Samples - To provide a check on the analy tical laboratory , Battelle laboratory staff prepared two spiked wipe samples for analy sis with other sampling data in each unit. One wipe was spiked at 20 micrograms of lead and the se cond at 40 micrograms. Table 4 shows the Microba c labora tory analy tical re sults for t

hese spik ed sample s.Final Report 30 Decem ber 28, 2005 Ta ble 3

. Field B

lank Sample Results2 NIST certified 9761 mg /kg with 95 percent prediction interval of ± 67 mg/kg for samples of at l east 1 00 mg.
Final Report 31 Decem ber 28, 2005

Table 4

. Samp lin g R

esu lts f ro m B

at t ell e L abo ratory Spi ke QC Samp les

In 9 of the 62 samples (highlig hted in gray

), the measured recovery

was outside the QAPjP requ

irement o f +/- 20%

of the ta rget va lues. The se sample s exhibit g reater variabi lity than expected in the spiked sample recoveries. Additionally, the average measure d recovery was 90.5 per cent for the 20 microgra

m samples a

nd 90.8 pe

rcent f or the 40 m

icrogr am sample s. This suggests also a potential bias in sample recover ies. However, the small amounts of SRM 2584 (nominal 1% lead 2 by weig ht) required to produce the 20 and 40 microgr am samples (two and four millig

rams, re spective ly)fall wel l below the minimum 100 m

g sample size at whi ch NI STFinal Report 32 Decem ber 28, 2005

has spec ified a k

nown unce

rtainty of the ma ss frac tion of lea d in the SRM. Theref

ore, it c ould well be that the fa

ilures an d bias re sult from v ariation (about one perce

nt) in the t

rue mass fraction of lead

used to spi

ke the sa mples.
If the observ ed bias is

reflective of the

laborat ory lead mea suremen

t (and not a bias in preparation of the spiked samples), it may indicate that the measured results from the wipe samples in the study are a rtificially low. To understand the impact of this possibility, the study results were adjusted under the assumption that laboratory measured lead levels were only 90 percen t of the tr ue lead l evels. These rec alculate d results were not d iffere nt for the primary data quality objective of asse ssing whether attaining white glove was reflective of meeting the clearance standard. The re calculated results did show minor changes for othe r study results. Laboratory

QC Samples - As part of its standard laboratory QC procedures, Microbac Laboratories perf

ormed QC samples including independent calibration verifica tions, independent calibration blanks, continuing calibration verifications and blanks, post-dig est analytical spikes and duplicates, and sample wipe laboratory blanks. These were collected consistent with the requirements of Table 2-2 in Section 2.4 of the QAPjP (see Appendix A). They are summarized in Table 5 below. Review of the QC data did not identify any deviations from the r equired frequency

or accept ance limi ts for the se sample s.
T abl e 5

. A nal y t ica l Labora t ory QC Sa mple Result sFinal Report 33 Decem ber 28, 2005

6.0 ANAL

YS IS RE SU L TS
This sect ion provid

es gra phical a nd tabula r summari es of the

data obta ined fro m the fiel d study as well a s detaile d discussi on of find ings with regar d to each of the stu

dy d ata qual ity objectives (as introduced in Section 3.1). Section 6.1 provides refere nce graphs and tables of the field study data. Section 6.2 conta ins a detailed discussion of the results by qua lity objective.
6.1 G r

a p h i c a l a n d Ta b u l a r

S u m m a r i e s

of R e s u l ts Five separate treatments were evaluated in the field study . These included:
– For Floors Dry Cloth to White Glove (or a maximum limit of 15 DCCs) - Graph 1 Dry Cloth to White Glove (or a maximum limit of 15 DCCs) Followed by One Wet Cloth - Graph 2 Wet Cloth to White Glove (or a maximum limit of 15 DCCs) - Graph 3
– For Window Sills Dry Cloth to White Glove (or a maximum limit of 3 DCCs) - Graph 4 Wet Cloth to White Glove (or a maximum limit of 3 DCCs) - Graph 5 Each of the scatter plots for these five trea tments display the relationship betwee n the lead loading on each test floor or window surfa ce before the protocol was beg un and the lead loading after completion of the cleara nce protocol. Note that for each floor test surfa ce, two wipe samples were collected before a nd after conducting each tre atment protocol. (The before and after wipe samples were collected side by side to minimize spatial variability .) The measurement results us ed in eac

h scatte r plot gr aph are the arith metic mea

ns of the p aired wi

pe sample measurements. For the window sill surfaces, only a single pre-protocol and post-protocol wipe sample were taken due to sill size limitations. Both the horizontal and vertical axes are a logarithmic scale. Each g raph inc ludes two t

ype s of points . The emp ty b oxes repr esent the data poin ts where the clearance pr

otocol achieved white glove. The pluses are the data points where the protocol failed to achieve white glove. Mea sured lead loadings less than the laboratory ’s minimum quantitation limit of 10 : g/ft2 are represented as one half this limit (i.e., 5 : g/ft2 ).Final Report 34 Decem ber 28, 2005

Finally, ea

ch graph shows dotted refere nce lines (both horizontally and ver tically) at the clearance standard (40 microg rams for floors, 250 micrograms for sills). Using the se lines, the graph s are se

parate d into four

quadran ts with the

following

labels a nd defini tions:

a. Points plotted in the upper left hand quadrant represent surfaces that were below the clearance standard before the DCC/WG protocol and ended up above the clearance standard afterward

. b. Points plotted in the upper right hand quadrant represent surfaces that were above the clearance standard before the DCC/WG protocol and remained above the clearance standard afterward

. c. Points plotted in the lower left hand quadrant represent surfaces that were below the clearance standard before the DCC/WG protocol and remained below the clearance standard afterward

. d. Points plotted in the lower right hand quadrant represent surfaces that were above the clearance standard before the DCC/WG protocol a nd fell below the clearance standard afterward

.

Graph 1 - Dry

Cloth to White Glove (or Max 15 Cloths) on FloorsFinal Report 35 Decem ber 28, 2005 Graph 2 - Dry Cloth to White

Glove (or Max 15 Cloth s) Followed by One

Wet Cloth on Floors

Graph 3 - Wet Cloth to White Glove (or Max 15 Cloths) on FloorsFinal Report 36 Decem ber 28, 2005 Graph 4 - Dry Cloth to White

Glove (or Max 3 Cloths ) on Sills

Graph 5 - Wet Cloth to Whi

te Glove ( or Max 3 Cloth s) on SillsFinal Report 37 Decem ber 28, 2005

Table 6 provides counts of surfaces over or unde r the clearance standard a fter completing each of the five treatments. The counts are grouped by

whether or not white glove was achieve d and whether the surface was initially above or below the clearance standard before performance of the pr otocol. I n this way

, Table 6essentia

lly p rovides t wo cross tabulations (achi eving w hite glove or not achieving white g love) of numbers of data points in each of the four quadr ants of Graphs 1-5.
Table 6

. Cou nts of Surfaces O ver or Unde r Cl earan ce Standar ds by Treatment , P reProtoc ol L

ead Loading, and W hit e Glov e St at usFinal Report 38 Decem ber 28, 2005

Table 7 presents an overall summary of the effectiveness of each tre atment. For surfaces achieving white glove, the number of surfaces sampled and the number below the standar d after perfor mance of the proto col are

shown. F rom these

two quant

ities, the estimate d protoco l succes s rate is c alculate d as:

This is an estimate of the probability that the lea d level of the surface will be below the clea rance standard given that the white glove condition was met. If the number of surfaces Below Standa rd After Pr otocol is d

esigna ted as s and the nu

mber of T otal Surf

aces as n , an estimated lower 95% confide nce boun d on the pr

otocol suc cess ra

te is:

This p signifies the true population success rate below which it would be unusua l (i.e., less than or eq ua l t o 5 % c ha nc e) to ob se rv e a s m an y or mo re su cc es se s a s w er e o bs er ve d i n t hi s s tu dy.
For surfaces that failed to achieve white glove, Table 7 shows the total number of surfaces, the number below the standard af ter the protocol, and the percentag e that met the clearance standard (despite f ailing to achieve white glove).
T able 7

. Ove rall D CC/ W G Clea rance Pro t ocol Succ ess R

at es by T reat mentFinal Report 39 Decem ber 28, 2005

6.2 R es u lts b y Data Q u al ity O b

je ctive
6.2.1 Dat a Qual ity Obj ect ive 1 The first data quality obje ctive of this study was to estimate the proba bility (and corres ponding one-side d 95% lowe

r confid ence bo und) that surfac es will ac

hieve the appropr iate clearance standard (as de

termined by wipe sa

mpling), given that the floor or window sill surfaces have pa ssed the w

hite glo ve test us ing the D CC/WG clea rance p rotocol. Table 7 provides t hese estimate s for ea

ch of the protocol variations examine d on floors and sills. In Table 7, eac

h of the five treatments is listed in a separate row, identified by the surface type (floor or

sill), corresponding clearance standard, and specific variation of the protocol tested (wet, dr y, or a combi

nation). Data Qua

lity Objectiv e 1 is conc erned with the por tion of the

table for ‘Surfaces Achieving White Glove.’ F urther discussion is provided for each of the five treatments in Sections 6.2.1.1 through 6.2.1.5. 6.2.1.1 Data Quality Objective 1 - Dry Cloth to White Glove Treatm ent on Floors. The first row of Table 7 shows that 47 floor surface s out of a total of 58 treated floors achieved white glove with the dry

cloth treatment. In 43 of these 47 c ases, the post-treatment protocol mean wipe sample results were at 40 : g/ft2 or less. T his result s in an est

imated 91 .5% succ ess rate. The lower bound for a one-sided 95% confidence interval for this estimate is an 81.6% success rate. Hence, the results from this study provide strong evidence (i.e., 95% conf idence) that the protocol would be effective in similar housing at least 81.6% of the time. The results for this treatment were shown in Graph 1. Further examination of the dry protocol results is provided under Data Quality Objective 2 (Section 6.2.2). 6.2.1.2 Data Quality Objective 1 - Dry Cloth to White Glove + 1 Wet Cloth Treatm ent on Floors. For ea ch of the 47 surfa ces that achieve d white g love with t he dry cloth treatme nt, a single additional clea rance w iping wa s perfor

med with a

wet cloth . Only

38 of thes e 47 surfaces (second row of Table 7) showed mean wipe sample results of 40 : g/ft2 or less after the additional wet cloth. This corresponds to an estimated 80.9% success rate . The lower bound for a one -sided 95 % confid ence int erval f or this est imate is 69 .0%. Hen

ce, the r esults fr om this study provide s trong e

vidence (i.e., 95 % confid

ence) t hat the pr otocol wo uld be ef fective in similar housing at least 69.0% of the time. The results for this treatment were shown in Graph 2. The poor er estima ted succ ess rate

for this tr

eatment ( 80.9%) a s compar ed to the d

ry cloth treatment alone (91.5%) was unexpected. L aboratory data collected on smooth vinyl tile floors had shown that a protocol that included a wet cloth mopping after reaching white glove with dry cloths was more effective at reducing lead levels than the dry

cloth treatment alone. While the result from this study is not explained, one hy pothesis is that the single wet cloth loosens and disburses significant lead from cracks or c revices that subsequently become available to a wipe sample collection but which would not have been accessible af ter a dry cloth treatment alone.Final Report 40 Decem ber 28, 2005

Also, it should be noted that though the dry c loth treatment alone has a higher estimated effectiveness than the combined dry and wet cloth treatment, the difference obse rved in this study is not stati stically

signific ant.
6.2.1.3 D ata Quality

Objectiv e 1 - Wet

Cloth to W hite Glo ve Treat ment on Floors
. The wet only DCC/WG cleara nce protocol performed best of the three D CC protocols tested on floors (third row of Table 7 and Graph 3). The wet cloth protocol passed clearance for 36 of 37 surfaces where white glove was achieved, corresponding to a 97.3% success rate. The lower bound for a one-si ded 95% c onfidenc e interv al for thi s estimate is 87.8%. H ence, the results from this study provide strong e vidence (i.e., 95% confidence) that the pr otocol would be effective in similar housing at least 87.8% of the time. Although hig her than the results for either the Dry or Dry+1 Wet trea tments, the observed success rate for the wet pr otocol was not statistically significantly

better than either of the other two. Though not statistically sig nificant, the order of observed effe ctiveness (dry +1 wet, dry only , wet only

), if true , is still puzzli

ng: Why would one

wet cloth not improv e on the dr

y r esult but multiple wet cloths would have the best observed performance? A possible explanation for the poorer performance of the dr y+1 wet c loth treatment compared to the dry cloth only treatment was presented in 6.2.1.2 above. The logica l extension to this hypothesis is that the additional leaded dust exposed by the we t cloth cannot be adequately removed with only one we t cloth. Howeve r, multiple

wet cloth s will eve

ntually remove i t and ultima

tely leave e ven less a vailable leaded d ust for a dust wipe s ample tha

n a protoc ol based on dry DCCs.
6.2.1.4 D ata Quality

Objectiv e 1 - Dry

Cloth to W hite Glo ve Treat ment on Sills. The fourth row of Table 7 shows that 27 of 28 (96.4%) sills receiving the dry cloth to white glove treatment where white glove was a chieved were found to be below the clea rance standard of 250 : g/ft2 . This corresponds to a lower 95% confidence bound of 84.2% on the protocol success rate. One impor

tant factor with th e sill res ults (as se en in Gra

ph 4 and on

Table 6)is that only

a small number of sills that reached white glove with this treatment (six sills) were initially above the cleara nce stan dard bef ore appl ication o f the tre atment. Also, the su rface of the sin gle win dow sill that fail ed clea

rance was one of

those initi ally

above the

cleara nce stan dard and that it wa s in especially poor

condition with deterioration to the paint and underly ing wood.
6.2.1.5 D ata Quality

Objectiv e 1 - Wet

Cloth to W hite Glo ve Treat ment on Sills. The fifth row of Table 7 shows that 25 of 25 (100%) sills receiving the wet cloth to white glove treatment where white glove was a chieved were found to be below the clea rance standard of 250 : g/ft2 . This cor

responds to a lower

95% conf

idence b ound on the

protocol success rate of at least 88.7%. As

with the dr

y c loth proto col, only

a small num

ber of si lls that re ached w hite glo ve with this treatment (seven sills) were initially above the clearance standar d before application of the treatment (as seen in Graph 5 and on Table 6).Final Report 41 Decem ber 28, 2005

6.2.2 Dat a Qual ity Obj ect ive 2 One objective of this field study was to compare the results obtained with those of the Second Controlled Room Study (see Appendix E). I n the Second Controlled Room Study, the effectiveness of the DCC/WG clearance pr otocol was examined on a single floor surface and with predetermined lead contamination levels. The planned nature of this previous study is the source of the ‘controlled room’ name. I t is titled the ‘second’ controlled room study be cause an earlier controlled room evaluation was perfor med (see Appendix C). For simplicity, future references in Section 6.2.2 to the Second Controlled Room Study will refer to it as the controlled ro om st ud y. The experimental design for the controlled room study involved spiking a vinyl tile floor (48 ft 2 test areas) with one of two lead-containing standard reference mater ials (SRM #2584 = house dust with 1% lead, SRM #2589 = pulverized paint with 10% lead). For each test are a, carefully measured quantities of the SRM were uniformly dispersed over the entire 48 ft 2 area at one of four different lead loading s: 40 : g/ft2 , 200 : g/ft2 , 600 : g/ft2 , and 1600 : g/ft2 . Each of the two SRM/lead concentrations and four lead loading combinations was re peated three times for a total of 24 floor areas tested (2 x 4 x 3 = 24). A DCC/WG clearance protocol (similar to the dry cloth treatment used in the field study) was executed for each floor test area and was followed by collection of four clearance wipe samples from each floor test area. B y comparing the wipe sample results collected after the protocol with the known (initial) lead spiking levels, the effectiveness of the treatment was eva luated for each lead loading/lea d concentration combination.
6.2.2.1 C omparis on of Dry DC C/WG Tre atment Between C ontrolle d Room an d Field Study. The f

ollowing s ecti ons se

para tely outli ne th e res ults f or the dry DCC/WG treatment in the controlled room study ( Section 6.2.2.1.1), the field study (Section 6.2.2.1.2), and then the comparison of the two results (Section 6.2.2.1.3). 6.2.2.1.1 Dry Cloth to White Glove in Second Controlled Room Study. Gr ap h 6 di sp la ys the comparison of the means of post-protocol lead loadings to initial lead loading s for the dry DCC mopping protocol executed in the Second Controlled Room Study in late 2003. As described above, each floor surfa ce was spiked with a carefully measured mass of lead (approximately 40, 200, 600, or 1,600 : g/ft2 ) in one of two different concentrations (1% a nd 10% by weig ht).Final Report 42 Decem ber 28, 2005

Graph 6 - Dry

Cleaning Cloth to White Glove on Floors - Second Controlled Room Study (2003)

Graph 6 shows a linear regre ssion model fit of the post-protocol lead levels versus the initial lea d loading (after log-tr ansform ing both measure s). The mo del shows a modera tely strong linear relationship (r 2 = 0.83) between the dependent (post-protocol lea d loading) and independ ent (initi al lead lo ading)variabl es. Thoug h depicte d individua

lly, there wa s not a statistica lly s ignific ant diffe

rence i n relationship betw een the 1 % and 10% SRM conce

ntrations

. Graph 6 a lso shows a

n upper 9 5% confi dence in terval f or a single predi cted val

ue. I t is this upper predict ion interval that is o f partic ular inte rest, es pecially at the poi nt where it intersects the horizontal reference line (40 : g/ft2 ) for the clearance standar d. The intersection point in Graph 6 falls at approximately 385 : g/ft2 . This mea n that we a

re 95% c onfident

that a floor with an initial (pre-treatment) lead loading of 385 : g/ft2 or less would pass clearance based on th e d at a f

ro m t he co nt ro ll ed ro om st ud y.Final Report 43 Decem ber 28, 2005

6.2.2.1.2 Dry Cloth to White Glove in Field Study in Residential Housing. Graph 7 display s the rela tionship of

the mean s for post-protoc ol to initia l lead loa dings for the dry

cloth DCC/WG protocol from the current field study in r esidential homes. These data are the same as plotted in G

raph 2 exc ept that the data po ints for the floor s urface s that did not achie ve white glove are excluded because they are not relevant to this assessment of protocol success. The point where the upper 95% prediction interval for Gr aph 7 intersects the clearance standa rd line falls at approximately 45 : g/ft2

.

Graph 7 - Dry Cleaning Cloth to White

Glove on F loors - Field Study in Residential Housing (2004)

It should be noted that the linear reg ression model fit (and accompany ing upper 95% prediction interval) have two important limitations as compared to the model for the controlled room study : (1) the a ssumption o f equal v arianc e about the regr ession fit line see ms much les s reasona ble than i t does for Graph 6, and (2) t

here ar e many censore d values i

n this data

set (also relates to the first limitation). Henc e, while a regre ssion line has been f it throug h the data , it sh ou ld be in te rp re te d c au ti ou sl y.Final Report 44 Decem ber 28, 2005

6.2.2.1.3 Comparison of Second Controlled Room Study and Field Study in Residential Housing - Dry Cloth to White Glove. The intersection point for the upper 95% prediction interval with the 40 : g/ft2 clearance standard ref erence line is lower in the field study (45 : g/ft2 ) than in the controlled room study (385 : g/ft2 ). The interpretation of this finding is that the controlled room study sug gests the possibility of ultimately achieving a passing clea

rance level with the DCC/WG clearance protocols when starting from a muc h higher initial lead loading than what app ears ac

hievable based on the field study results. Although the true reasons for the differ ence in the prediction intervals between the two studies are not known, some observations may clarify the

situation. The research staff involved in both stud

ies noted that the f ield study involved a

more com

plex lead- contamination sce nario than in the

controlle d room. Th e contro lled room s tudy involved ‘ spiking’ with lead ed dust ‘sprinkled uniformly’ onto the floor surfaces, which were then misted with water a nd left to dry. The objective of misting with water was to develop some adhe sion between the floor surface and the lead dust. It is conjectured that a relatively hig

h proportion of this recently de posited (and water misted) lead dust was easy to remove with a dry

DCC. By compari son, in some

of the re al-worl d sites of t he field study , lead dus t adhere d to floors far more strongly

than in the controlled room. Leaded dust ha d probably bee

n accumulating on floors over a long time a nd may have be en mixed with sticky substances such as wax and grease. Under these c ondition, the result was a much stronger adhesion of lead to the floor sur faces. A floor with cake d-on, dri ed grime prese nts speci al proble

ms for the

dry cloth treatment. The dry

cloths reach a point where no additional free dir t or debris are collected (i.e., white glove is achieved) but the ground- in dirt or dried residue still retains lead that can be dissolved by moist clea

rance w ipe sample

cloths. Cle ar adhe sion of le ad-cont aining g rime to surfac es can be

a critic al issue in

real-world situa

tions. Another critical factor is the condition of the floors (and window sills). I n the controlled room study, the viny

l tile floor was in excellent condition with no observable cracks or crevice s. Many of the fie ld study

floors exhibited considera ble dama ge and deterioration. F loors with exposed wo od gra

in, disinte gratin

g wood, or with fr

equent c racks a nd crevi ces are

problema

tic for cleaning and sampling. They tend to capture and retain lead dust even af ter cleanup. So, the factors of floor condition, lead-dust contamination and the interaction of the two may acc ount for the diffe rence o bserved betwee n the two st

udies in th e appar

ent eff icacy of the dr y c loth treatment. In the final analy

sis, Graph 6 and Graph 7 clearly show that dry cloth trea

tment performance was far be

tter in the controlled room than for the field study . The controlled room study employ ed a cle an viny

l floor tha t was in g ood condi

tion. L ead-containing

materia ls (SRM 2584 and 2589) were recently applied. The adhesion and entrapment of lead par ticles that inevitably occurs in the r

eal-world sites was not a serious issue in the controlled room study . As such, the controlled room study may be viewed as a near-best-ca se scenario demonstrating how well the dry DCC/WG cleara nce protocol might be expected to perform under idea l conditions.Final Report 45 Decem ber 28, 2005

6.2.2.2 Comparison of Dry+1 Wet DCC/WG Treatm ent Between Controlled Room and Field Study. As in the current field study , the controlled room study also examined variations on the D CC/WG clea rance p rotocol. The cont

rolled ro om study

included some tria ls with a single wet DCC after the dry DCC/WG treatment had been completed. This protocol variation was performed on nine floors for a le ad loading level of 1600 : g/ft2 . Graph 8 is a duplicate of Graph 6 except that it includes these additional data points with a wet DCC. They are ide ntified a s the fille d-in data points and

are all a t an initia l lead loa ding of a pproximate ly 1600 : g/ft2

. Graph 8 - Dry

DCC/WG and Dry + 1 Wet DCC/WG Treatments on Floors - Second Controlled Room Study (2003)

From Graph 8 it can be seen that the inclusion of a single wet DCC after the dry DCC/WG clearance protocol produced a reduc tion in the mean lead loading compared to the comparable points with only the dry DCC/WG treatment. Floors starting at 1600 : g/ft2 lead contamination and

treated with the dr

y D CC/WG clea

rance p rotocol r eached a mean po sttreatment lead level of 49.1 : g/ft2 (standa rd devia tion=17.3 ). Adding

one addit ional wet DCC mopping to floors contaminated at the same initial level resulted in a post-treatment leve l averaging 16.0 : g/ft2 (standard deviation=5.6). (Note that the dry +1 wet treatment points are offset slightly to the rig

ht in Graph 8 so they ca

n be clearly

distinguished from the dry treatment only points. Both sets of points are at ve ry near ly 1600 : g/ft2 lead loading before perfor mance of their respective DCC/WG clearance protocols.)Final Report 46 Decem ber 28, 2005

As wa s disc

usse d in 6. 2.1.2 , the

appl icat ion of the d ry cloth + 1 we t clot h DCC/ WG clearance protocol in the field study did not produce a statistically sig nificant improvement over the treatment with the dry DCC alone. The controlled room study did see m to show better protocol performance with the addition of a wet DCC. Within the context of the previous discussion, the apparent contradiction in the two study results may be explainable. F or the controlled room study wher e (1) floor conditions were very good, (2) the application of the leaded material was recent, and ( 3) attempts to produce adhesion were minor, the addition of a sing le wet DCC w as su ffic ient t o sig nific antly improve le ad re duct

ion re lativ e to a

dry DCC/WG treatment alone. In the fie ld study with many floors in poor condition and firmly adhe red leaded matter, a single wet DCC was not sufficient to improve lead re duction relative to the dry DCC/WG trea

tment alone. Howe

ver, multi ple wet D CCs in the fi eld study could eve

ntually break down and re

move the more embe dded lea ded mate rial.
6.2.3 Dat a Qual ity Obj ect ive 3
A number of covariate factors re lating to the performance (succe ss or failure) of the DCC/WG clearance protocols were examined. The primary focus of this analysis wa s the scenario of meeting the clear ance standard when white glove is ac hieved. Covariates that were examined included the specific DCC/WG clearance protocol perf ormed (Section 6.2.3.1), the pre-treatment lead contamination level (Section 6.2.3.2), and other covariates (Section 6.2.3.3). Additionally, this field study incorporated an evaluation of whether the spe cific cleaning solution used had an impact on the performance re sults (Section 6.2.3.4).
6.2.3.1 Performance of DCC/WG Cle arance Protocol by Treatm ent Type. The results f or each DCC/WG clea

rance protocol on floors a nd sills wa s discusse d under D ata Quality Objective 1 (Sec

tion 6.2.1).

• The observed performance of the wet treatment on floors (97.3%) was gre ater than that of the dry tre atment (91.5%) which in turn was greate r than that of the dry

+ 1 wet trea tment (80. 9%). How ever, the compar isons of e ach pair

of trea tments in th

is set using Fisher’ s exact test shows tha t none of t

he diffe rences are sta tistically signific ant when

the joint c onfidenc e level f or the thr ee pair wise comp arisons is 95%. Hence, there is not sufficient evidence to conclude that the true performance of any of the

three DCC/WG treatments on floors are different from ea ch other. However, it should be noted that the small sample sizes limit the likelihood of identifying a

sample difference as statistically significant unless the true population difference is fairly

large. This study

showed approximate 80% power (probability of concluding a difference w hen one actually

does exist) when one treatment’s performance was 95% and either of the comparison treatments was at least 30% poorer.Final Report 47 Decem ber 28, 2005

• The observed performance of the wet treatment on sills (100%) was greater than that of the

dry treatme nt (96.4% ). Howev er, comp arison of these two

treatme nts with Fishe

r’s exac t test show s that the d iffere nce between them

is not stati stically signific ant with 95 % confid ence. T he small sa

mple size affects t

his compa

rison just as for the floor treatments. The statistical comparison of sill performanc e by treatment has approximate 80% power when one treatment’s pe rformance is 95% and the comparison treatment is at least 30% poorer.
6.2.3.2 P erform ance of DCC /WG Clea rance P rotocol by Pre-treatm ent Contamination Level. For the dry treatment results on floors (see Graph 1), there does appear to be a relationship between pre-protocol contamination levels a nd final lead loading achieved upon rea ching w hite glo ve. This r

elationsh ip is most ap

parent w hen initia l lead loa ding lev els exceed about 20 : g/ft2 . (Bec ause of t he heav y c ensoring

effec t of the me

thod dete ction limit i

n this study, it is not possible to examine this relationship at lower initial lead loading levels.) Generally , floors initially contaminated at hig her lead levels were observed to have higher final lead loa dings af ter rea ching w hite glo ve. Howe

ver, the re is con siderab le varia

bility about this relationship. As discussed earlier, it is believed that the success or fa ilure of the dry tr

eatment at higher initial lead loadings lies in whether the lead c ontent is contained in loose dust or whether the lead is somehow bound to the floor surface. I f lead is contained only in loose dust, the dry treatment can achieve white glove and reduce lead loadings to levels equivale nt to that of a floor with lower initial lead levels (though, of course, it may require more dry

DCCs to do so). Howeve r, if the l ead is tig

htly bound to the

floor sur face, t he dry protocol can be susceptible

to attaining white glove when no further le aded material can be picked up by this protocol even though there are higher

remaining levels of lead that could be collecte d (as with a wet clearance wipe). For the dry

+ 1 wet treatment results on floors (see Graph 2), the conclusions appear very similar to the dry treatment a lone. Unlike the treatments with the dry DCCs, the wet DCC/WG clearance protocol results on floors appear equally

effective across the entire ra nge of initial lead concentrations encounter ed for this field study (ave

rage of side-by

-side measurements ranging f rom less than 10 : g/ft2 to a maximum of 375 : g/ft2 ). This can be seen in Graph 3. Of course , because of the heavy censoring effect of the qua ntitation limit, it is possible that some trend exists below 10 : g/ft2

. Regardless, the result is still clear that across a wide r ange of initial contamination levels, the wet treatment consistently and substantially reduced lead levels to well below the clear ance standard. For both the dry

(see Graph 4) and wet (see G raph 5) treatment results on sills, there is no obviously visible relationship between mea sured lead level after the DCC/WG clearance protocol compare d to befor

e the pro tocol. For both tre atments, t he rang e of initia

l lead loa dings on sills extended from less than 10 : g/ft2 to more than 2,000 : g/ft2 . There fore, it d oes not ap

pear wit hin this range of initial lead loadings that the pre-pr otocol contamination level had a significant effect on the lead loading attained a fter the protocol.Final Report 48 Decem ber 28, 2005

6.2.3.3 Performance of DCC/WG Cle arance Protocol as a Function of Other Covariat es. The primary sta tistical results from this study are pre sented for each treatment as the proportion of surfaces achieving w hite glove that were found to have residua l lead contamination below the clearance standard. I t would be desirable to ascertain whether the observed results can be associated with additional covar iates encountered in the field study such as: (1) size of surface treated, (2) ty pe of surface material, and (3) initial condition of the surf ace. The small sample size

for this st

udy and the f orm of the

perfor mance e stimates ( i.e., pro portions) preclude a robust statistical evaluation of the effec ts of these covariates. However, Table 8 provides a summary of

the characteristics of the surface s that failed (i.e., reached white g love but were no t below the

cleara nce stan dard) a nd compar

es these to all surf

aces te sted in the

field study.
Table 8

. Cova riat e Levels f or DCC/ W G Clearance Prot ocol Failur es Compared t o All Sur f aces

From the summary r

esults in Table 8, the average trea ted surface areas, distribution of surface material ty

pes, and average initial surfac e condition codes are similar between the surfaces that failed to meet the cleara nce standard (after rea

ching white glove) and the entire sample of surfaces in the field study . One possible exception is the sill that did not meet clearance after re aching white glove. The surfa ce condition code for this sill is poorer (at 4) than most other sills encountered in the study (a verage of 1.9).Final Report 49 Decem ber 28, 2005

Additional anecdotal observation of covariate results included:

• Wood floor

surfac es that we

re not fin ished and sealed ( e.g., w

ith poly urethane) did not fair p oorly

in reduction of lea

d but they did prese nt diffic ulties in a chieving white glove.

• Floors with cracks, splinte ring, or protuber ances ( dried spa

ckle, sta ples) mad e it operationally diffic

ult to perform the protocol because the DCCs would tear on the imperfections. Interestingly, though, despite the f act that the protocol could not be recommended from an operational standpoint on these surfa ces, the reduction of lead levels wa s often ju st as succ essful he re as on smoother s

urface s.
6.2.3.4 P erform ance of Wet DCC/WG

Clearanc e Protocol as a F unction of Cle aning Fluid Use d. A question

raised in the deve lopment of

the study plan was whether the resu lts observe d for the

wet trea tment woul d be appli cable on ly f or the spe cific cl eaning

fluid use d with the DCCs. T

his issue is

important

because it ultimate ly b ears on how a fina l recomme

ndation is made for which wet DCC products are acc eptable. To examine this study question, two differe nt mopping products were evaluated. Additionally , for a small number of floors, a change was made to the experimental protocol on floor surfaces to evaluate the effects of using plain tap water as the cleaning fluid rathe r than the mop manufacturer’s own deterg ent. Table 9 shows the relevant results from this evaluation.
Table 9

. Co mp

ar i s o n of W et DC C/WG C l ea r an ce P r o toc o l P er for ma n ce w i th T w o Comm erci all y A vailab le Cl eani ng Sol utions

and W at er

Unit - Mop Used First Half of Room Second Half of Room

Cleaning Solution Lead L oading

( : g/ft2 ) Cleaning

Solution Lead L oading

( : g/ft2 )PreProto col PostProto col PreProto col PostProto col 28 - Swiff

er® WetJet® Swiffer 42 <10 Water 50 <10 41 16 63 11 29 - Clorox® ReadyMop® Clorox 47 16 Water 16 17 40 9 18 14 30 - Swiff

er® WetJet® Swiffer 81 <10 Water 61 <10 80 <10 62 <10Final Report 50 Decem ber 28, 2005

The results obtained appear repeata ble whether using the two commercial clea ning solutions or water. If true, this may imply that it is not actually the specific formula of the detergent that is important in achieving succe ss with the wet DCC/WG clearance protocol but the fact that a liquid is used at all. However, the very small sample size of this evaluation precludes coming to a definitive conclusion on this issue and further study is recommended.
Note that due to the

compara bility of resul ts for the differe nt clean ing solut ions (as w ell as water), results presented elsewher e for the wet DCC/WG clearance protocol in this study are made without distinction as to which cleaning solution was used.
6.2.4 Dat a Qual ity Obj ect ive 4 Data Quality Obje ctive 4 was created to examine those cases wher e a DCC/WG clearance protocol was completed but white glove was not achieve d. It was asserted that a be neficial concept of the white glove test would be that it recog nized its own limits. That is, if the protocol failed to achieve white glove, it would be an indication that the c learance standard had not been me t a nd th at a m or e t ho ro ug h c le an in g o r s ur fa ce re fi ni sh in g w as ne ce ss ar y. Table 7 (presented in Section 6.1) showed, by treatment, the proportion of surfaces that had measured lead levels below the clear ance standard even though white g love was not achieve d. The re sults are surprisin gly similar to t

he perf ormance of the tre atments w

hen white glove w as achie

ved. With F isher’s e

xact test, n

one of the five tre atments exhibited a st atistica lly signific ant diffe

rence i n perfor mance be tween the surfac es that re ached w

hite glo ve and tho se that did no t. There fore, w e canno t conclud e that whe

ther a tr eatment r eached white g love in this field stud y impacte d the f inal e ffecti venes s of th e treat ment i n redu cing th e surfa ce lead loadi ngs to below the clearance standard. Howe ver, it should be noted that the small sample sizes involved in these comparisons do not preclude the possibility that some true (and possibly larg e) differences do exist. Table 10 provides summary statistics on the average and standard de viation of the number of DCCs required to reach white glove for each treatment as well as the cor responding average and varia

bility in number of DCCs when white glove was not achieved.Final Report 51 Decem ber 28, 2005

Table 1 0

. Av erag e Numb ers of DCCs Used

Those surfaces that did not meet white glove had on a verage about twice the number of DCC moppings used as surfaces where white g love was achieved. I

t is possible that the surfaces not meeting white glove achieved c omparable performance to those that did meet white glove because they had so muc

h more cl eaning

and what ever re maining soiling that led to the white glove f ailures was not hig

hly related to recov erable

lead con tent.
It is im portant to reitera te the poi nt previo usly made abo

ut the numb er of DCCs

used in this field evaluation compared to what would be used in a real-world application of the protocol. The very high numbers of DCCs used in this field study we re the result of minimal initial cleaning of surfaces and this minimal cleaning was intentional to allow an evaluation of the DCC/WG clearance protocols in the worst case scenar io (i.e., an inadequate cleanup after R&R). Effect ively , some por

tion of the

DCCs used in

the field evaluat ion were principa lly s erving

as a cleaning tool and not as a clearanc e evaluation (though, of course, the two purpose s cannot be strictly separa

ted). In a rea

l-world incorporation of these protocols, it is expected that a more efficie nt clean ing step would be mandated

before applica tion of the

DCC/WG clea

rance p rotocol.
6.3 A ddit ional Results and D iscussion
When examin

ing the r esults fr om this study

across t he diffe rent dat a quality objectiv es, some res ults and c onclusion s appear that are global r ather th an isolate d to one DQ O. This section presents each of these differe nt issues.Final Report 52 Decem ber 28, 2005

6.3.1 E f f ect ofReaching W hit e Glov e on E f f icac y of Tre at ment From Table 7, it is noteworthy that only 37 out of 58 floors passed the w hite glove test for the wet treatment as compared to 47 out of 58 floors for the dr y treatment. The

experiences of those performing the protocol was that white g love could be reached more often for the dry treatme nt than the

wet. Aft er the dr y tr eatment had remov ed any non-adh ering d

irt and du st, subseque nt dry DCCs would a

ppear w hite eve n if there was sig nifican t visible di

rt and g rime remaining on the surface. Thoug h dry DCCs could not pick up this remaining dirt, the c learance wipe sample collection could. This effect would account for the lower observed success rate of the dry trea

tment in predicting clearance has be en met. Conversely, the wet treatment sometimes could not reach white glove (i.e., wet DCCs continued to be discolore d after mopping) even though visual inspection of the surface showed no re maining dirt or dust. A very interesting result of this study, as shown in Table 7, wa s that the effectiveness of the wet protocol on floors when whit

e glove was ach ieved (3 6 of 37 = 9 7.3%) wa s almost ide ntical to t he effe ctivene ss when white glove was not achieved (20 of 21 = 95.2%). This suggests that whatever material continued to discolor the wet DCCs (and result in white glove failures) may not have been a lead reservoir. These materials might include bits of the floor f inish or even of the flooring itself.
6.3.2 Represent at ive ness of Field St udy Locat ions t o R & R P opulat ion
The data collecte d from the

field stud

y a re repr esentat ive of a c ertain p opulation of real

world hou sing unit s. To addr ess the a pplicabi lity

of the pr oposed c learance testin

g protoc ol to the R&R po

pulation in

gener al, it is ne cessar

y to determine to what e

xtent the fi eld study

units reflect the R&R p opulation at larg e. One in

dicator that the sa

mple from

this field study is “representative” would be if the lead le vels encountered before application of the pr otocol are consistent with R&R experience. No source is known for true R&R experienc e but two studies provide some relevancy

to this issue. The EPA report “Analy sis of Lead Dust Clearance Testing,” EPA 747-R-01-005, December 2001, includes a summary of first site visit wipe sampling results across eight differe nt sources, collected over the period from 1989 to 1999, in lead ha zard control and abatement locations. For these sources, the median lead loading s ranged, on floors, from 5 to 48 : g/ft2 and the 90 th percentiles from 68 to 418 : g/ft2 . On sills, the median ranged from 17 to 443 : g/ft2 and the 90 th percentiles from 175 to 1624 : g/ft2 . For the present field study , the median level before apply ing the D CC/WG clea

rance protocol ( counting

only those sur faces w hich woul d ultimate ly achieve white glove) was 48 : g/ft2 with a 90 th percentile of 202 : g/ft2 on floors and 45 : g/ft2 with a 90 th percentile of 401 : g/ft2 on sills. The similar median and 90 th percentile values for all floors (including those where the DCC/WG clearance protocol did not achieve white glove) were 56 : g/ft2 and 225 : g/ft2 , respectively . On sills, the median and 90 th percentile of all surfaces in the field study were

63 : g/ft2 and 703 : g/ft2 , respectively . Hence, it would appear that the lead levels encountered in the field study are at least similar to those found in lead hazard control and abateme nt progr ams.Final Report 53 Decem ber 28, 2005

The rep ort, “L ead Exposu re Assoc iated wit

h Renovat

ion and Re

modeling Activitie s: Environmental Field Sampling Study, Volume I : Technical Report,” EPA 747-R-96-007, May 1997 provides information on lead levels encountered after performing some ty

pes of R&R work and subse quent cle anup. The evaluat ions in this s tudy

were sim ulated a nd are not necess arily repres entative

of real -world R&R work. However, they do provide

insight in

to the lea d levels that might be encountered under cer tain types of work pr

actices. Specifically , drilling followed by a broom or va

cuum cleanup of floor areas resulted in mea n post-cleanup lead levels of 130 and 147 : g/ft2 , respectively , at five to six feet from the activity. Abr asive sanding followed by the same two cleanup methods produced even hig her average post-cle anup measurements; 865 and 357 : g/ft2 , respec

tively . These le

vels are higher , on aver

age, than what w as encou ntered i n the field study . Howeve

r, it should

be noted t

hat each estimate

has a fa irly large uncerta inty associated with it and that the type s of cleanup evaluated (broom and vacuum) a re not expected to be ade quate in c onjunction with the D CC/WG clea rance p rotocol. In addition to the lead loading leve ls, the experience of the field study suggests that surfac e conditi on (both in terms of d

eterior ation and cleanliness) is an

important

factor in determining the effectiveness of the D CC/WG clearance protocol. The gener al impression of the team conducting the study was that the selection of the units in this study resulted in a dispropor tionate n umber of residences with s

urface s in poore

r condition than the

y e ncounter in their normal lead hazard control and abatement work.Final Report 54 Decem ber 28, 2005

7.0 CON CL

USIONS Several important conclusions are sugge sted by the analy sis of the residential field study data.
Wet Tre atment

of DCC/WG

Clearanc e Protocol Ver y Success ful In every case for sills and in all but one case for floors, when the wet treatment was used and white glove was attained, the aver age wipe sample results confirmed that the surf ace was below the cleara nce stan dard. On floors, the protoc ol was est imated to b e 97.3% su

ccessf ul with lower 95% confidence bound of 87.8%. On sills, the protocol was estimated to be 100% successful with lower 95% confidence bound of 88.7%. Succ ess is the positive predictive value of the protocol and is defined as the ratio of true positive results (protocol a chieves white glove and clea rance s tandard

is met) to a

ll results that ach ieved wh ite glov e. The r

elativel y conserv ative low er conf

idence b ounds for

the resu lts are a result of the small s ample of

units in th e s tu dy. While the number of units was small, the results comprise housing units in two different cities, us ing a nu

mber of d iffere nt sampling

personne l, and cov ering a range of floor sizes, ty pes, and conditions. The sampled units were primarily lead hazard control and abatement sites so no definitiv e conclu sion can b e reached as to h ow repr esentat ive they are of t ypi cal R&R lo cations. Dry Treatment of DCC/WG Clear ance Protocol Not as Good as Wet The dry tre atment results for floors and sills in the field study we re not as good as the wet treatme nt results , but not dif

ferent enough to be stati stically

signific ant. The dry tre atment in the field study was less ef fective at reducing floor lea d levels than a similar treatment evaluated in the Second Controlled Room Study. I t is believed that this may be due to the more complex nature of the lead contamination in the real-wor ld environment (e.g., ground-in dirt and grime) than what wa s simulated in the controlled room experiment (e.g., sprinkled, misted, and dried lead-dust). Dry + 1 Wet Treatment of DCC/WG Clearance Protocol Less Effective Than Dry The hybrid trea

tment of the dry DCC/WG cleara nce protocol followed by

one additional wet DCC (e

valuate d on floors only

) was the poorest p erformi

ng proto col on ave

rage, though it was not statistically significa nt in comparison to the other treatments. A version of this protocol had quite strong r esults in li

mited test ing for the Secon

d Controlle d Room Study . Hence , it might still offer promise but would likely nee d to be re-evaluated and possibly re-defined (i.e., more tha n one wet DCC). The

one draw back of t his hy brid prot ocol will a

lway s be the ne ed to have both dry and wet D CC equipme

nt and supp lies.Final Report 55 Decem ber 28, 2005

“Smoot h and Cleanabl e” Crite ria Impo rtant Ope rationall y The selection of sampling surfaces base d on “smooth and cleanable” criteria likely will be an importa

nt part of any guidance. Contr

ary to expecta

tions, the floor sur faces s ampled th at did not strictly meet these re quirements often displaye d positive results in predicting clearance. Howeve r, the cr iteria a re import ant to the practic al execut

ion of any protocol

. No Other Covariate Results Were Definitively Linked to Treatment P erformance No significant effects were observed for the covariates of surfa ce area, surface ma

terial type, and surfa

ce condition in bivariate analy sis. Also, no significant effect was found for mop manufacturer and cleaning solution (manufacturer’s solution versus plain water). More complex multivariate analyse s were not possible based on the limited amount of data obtained. L ack of finding s here should not ne cessar ily b e interpreted to

mean tha t there a re no covariate e ffects, just th at no ne we re ob vi ou s f

ro m t he li mi te d s am pl e o f d at a i n t hi s s tu dy.
Failure to Reach White Glove Not a Good Indicator of Failing to Achieve Clearance Standard Among the small sample of units where white glove could not be r eached using one of the treatments, the post-treatment wipe samples showed in most cases that clear ance had been achieved any

way. Epidemiologically, this can be inter preted as the tested protocol having a poor negati ve predi ctive va

lue, whe re neg ative pr

edictive value is the ratio o f true ne gative results (failed to achieve white glove and le ad level is above clearance standa rd) to all results that failed to reach white glove.Final Report 56 Decem ber 28, 2005

8.0 PEER REVIEW EPA put the current study throug h a rigorous peer review pr ocess. This provided key stakehol ders and

experts in t

he field of lead hazard control and mitigati on the opp ortunity to assess the importance of the study results and to provide critical feedback. This section of the report summarizes the results of the peer review. Section 8.1 provides ba ckground on the peer review. Section 8.2 identifies several of the key points uncovered in the peer review proce ss and provides EPA responses. Additionally, many minor editorial issues were identified in the peer review process. These are not explicitly identified but they have be en incorporated in the final re po rt fr om th is st ud y.
8.1 Peer R

ev iew B ack ground A draft version of the current report wa s prepared in early August of 2005. EPA provided this draft in addition to a set of charge questions to a contractor that organized the peer review. EPA requested the peer review pane l collectively include individuals with all the following qualific ations:

• Employees of the F ederal Government with experience in measuring exposure to lead dust in residential settings, preferably including experience in sampling and lead clearance testing. EPA reque sted that two reviewers be recruited for this category , but not fr om th e s am e F ed er al ag en cy.

• Employ

ees of st ate, city , or loca l gover nments wit

h experie nce in me asuring

exposure t

o lead dust in residential settings, preferably including experience in sampling and lead cleara nce test ing. EPA request ed that one or two in

dividuals be selected from t

his ca te go ry.

• At least one statist ician who is familia

r with re sidential

lead dust contamination and

is capable of evaluating varia tion and uncertainty in indoor a ir data. Ideally

, this reviewer would hav e a M.S. or

Ph.D. in Sta

tistics.

• One individual from the priva te sector with pro fessiona l experien ce in lea d dust sampling , especi ally

sampling in indoor e

nvironme nts.

• One chemist with knowledge and experience in lea d sampling. In particular , extensive experience in ana

lyzin g wipe s amples is i

mportant. A panel of six individuals was selected that collectively met all the requirements above. Each re viewer r eceive d a copy

of the dr aft rep ort and a

set of charge q

uestions f rom EPA. These questions included four general and nine spec ific questions about the report and the prospect of implementing the technology examined in the report. Additionally, all reviewers were encouraged to provide any additional thoughts that would be useful to EPA. The reviewers were given a pproximate ly one month to complete their re views.Final Report 57 Decem ber 28, 2005

8.2 Peer R

ev iew R esult s Upon thei r rece ipt, EPA ca

refully reviewe d the coll ective p eer re view res ponses. I n some cases, EPA contacted the peer revie wer to obtain additional clarification. The gene ral impression of the peer revi ewers wer

e pos itive to the report and to the pro spec ts of u sing the D CC/WG protocol. However, some important questions were raised and c riticisms leveled. The issues listed below were selected as the most important due either to their pr evalence (i.e., a comment appearing from multiple reviewers) or their potential impact to the im pl em en ta ti on of

th e s tu dy r es ul ts in EP A’ s R &R ru le ma ki ng pr oc es s. In t hi s l at te r c at eg or y, comments made by the HU D lead program personnel wer e particularly

important (whether or not their co mments we

re shar ed by other pe er revi ewers) . Followi ng eac h key issue is a r

esponse from EPA. 1) Reviewe

rs indica ted that the overa

ll sample s ize for the

study was small

. EPA Response: A total of 58 separate floor surfaces a nd 29 window sills from 31 residential sites loca ted in 2 ci ties (with document

ed lead- based pa int hazard s) were

included in this fie ld study. Every

floor surface (58 floors) was divided into two are as that were treated by different DCC protoc ols. Two wipe sample s were c ollected and ana lyze d both bef

ore and a fter DCC treatme nt for ea ch trea tment are a. While thi s field stu dy was not lar

ge, it w as never

theless a major re search

effort i n which a substantia

l amount of

empirica l data wa s collec ted. This f ield study sys tematica

lly e xplored the

effec tiveness

of the DCC/

WG testing

protocol under a variety of challenging real wor

ld conditions. In addition, the field study employed essentially

the same DCC testing protocol that had already been thoroughly

tested under controlled laboratory conditions. The lab results were consistent with the f indings f rom the fi eld study . EPA belie ves that b oth the qua

lity and quan tity of the da ta was sufficient to conclude that the DCC method is useful and reliable for the pr oposed use. 2) Reviewers indicated that sites and work activities were not (or may not have be en) representative of R&R work. EPA Response: The residential units used for this field study inc luded both lead hazard reduction and R&R project sites. A wide, overlapping r ange of work activities are shar ed by both lead hazard reduction and R&R (e.g. sa nding, scraping, cutting, drilling) . At virtually every site where data was collected, some work ha d been done prior to data collection. EPA has no reason to believe the actual mix of work activities at each site and the pa rticular sites employed in this study are in any

way aty pical of R&R work. To actually attempt to define what constitutes a representative mix of R&R work activities and then ensure that those ac tivities were employed at these work sites would have presented an almost impossible logistical challenge for completion of this field study. EPA feels that it was better to view 'work activities' as a ra ndom effect for the purposes of this study design. That is, a random set of work activities that might reasonably

be expected to occur as part of R&R work wer e believed to have been conducted atFinal Report 58 Decem ber 28, 2005

these site s, but ther

e was no a

ttempt to do cument or

control f or speci fic work

activitie s. 3) Reviewe

rs commen

ted on the challen ge of d efining "Smooth a

nd Cleana

ble" flo ors. EPA Response: For the purpose of the field study , some floors were excluded. Based on expe rience in so me of t he fir st un its t ested , floo r surf aces th at were expe cted t o tear o r damage the disposable cleaning cloths (DCCs) were droppe d. Floors that were excluded from testing typ ically had brok en or spli ntering wood or th e floor s

urface /finish wa s so roug

h that it wo

uld have caught on and torn the DCCs. Surprisingly and une

xpectedly, for those floors with roug h or deteriorated surfaces that wer e tested before rough floors wer e dropped, they

often did not pass the 'white glove' test, but most of them still had post-treatment lead levels below the Federal hazard sta ndard. 4) Reviewers noted that the Unit 08 field blank did not y ield the expected “zero” result but that the remaining protocol wipe samples were not eliminated f rom study consideration. EPA Response: The QA procedure for an unusual re sult (either a failed quality sample or an outlier) is to examine the sample logs and other available information to identify if any explanation can be

found for the anoma

lous rec ord. I f none is f

ound, the unusual ob servation is identified in the results but the original data is not removed. This is the process that was employed for this ca se. Additionally, EPA thinks it important to point out this result in context of the entire study. The purpose of the field blanks was to provide assurance tha t the multiple wipe samples taken in a lead contaminated field environment had minimal risk of being cr oss-contaminated. The fact that only 1 of 31 field blanks showed le ad contamination above the method detection limit and this was at a relatively

modest level actually pr

ovides assurance that the field data collection procedures minimized the potential for errors dues to cross-contamination. 5) Reviewe

rs expres sed conc ern abou t the larg e number

of QAPP mod

ifications. EPA Respon se: The r

elativel y la rge nu mber of Q APP modific ations (1 4) refle cts the extreme care that was ta

ken in doc

umenting even minor chang es in the p lanned st udy protocol . Since thi s field study was conduc

ted at sites that displayed consider able variation in their phy sical characteristics, a number of adjustments to the data collec tion protocol were necessary . Even minor adju stments we

re car efully and thoro

ughly document

ed in the Q APP. 6) Revie w poin ted ou t that the DC C/WG proto col ma y lead to e xtra , unne cessar y cleanin g. EPA Response: EPA acknowledges that the DCC/WG protocol may sometimes result in extra cleanin g of flo ors. I

n order t o insure a high lev el of confidence

that the f loor lea d level f alls below the Federal hazard standard whe n white glove is achieved, extra cleaning may occur . The trade- off of e

mploy ing a me thod that ma

y r equire e xtra, unne cessar

y c leaning

to save th e time and expense associated with the use of wipe sampling appea rs worthwhile.Final Report 59 Decem ber 28, 2005

In addition, it must be noted that only a perfunctory

broom sweep of each floor was perf ormed prior to DCC treatment. This was done to increase the likelihood that a rang e of 'higher'lead loadings would be encountered during the field study. I

n actual practice, the DCC/WG protocol would be i

mplemente d after

a thoroug

h cleanu p had bee n complet

ed, so fe wer DCC tr

eatments would be likely to occur tha n were needed in the study . Hence, while additional cleaning may occur in an implemented version of the protocol, it is expected that its prevalence would be a lower proportion than was observed in this field study

. 7) Review id

entified a possible

bias fro m spike lab oratory QA sample

results. EPA Response: The recovery (average bias) for

the 20 : g samples is 90.5% and for the 40 : g samples is 90.8%. This observed bias may have been related to the prepara tion of the spike samples, either through the methodology employed in spiking sample w ipes or as a result of bias inherent in the SRM material. In this case, the bias should have had no effect on the laboratory wipe sample analy sis. However, under the assumption that the observed bias is a true labora tory measurement bias and that this bias is consistent throughout the study , the study results were recast assuming the true measured lea d levels should have been a factor of 10/9 g reater than observed. In this process, ver y little differenc e was found in the study r esults and no changes were found for the key

data quality objective of

protocol success rates. This observation has been ad ded into th e repor

t. 8) Reviewe

rs questioned the om

ission of w

indow trou

ghs. EPA Response: Testing of window troughs is a component of L ead Abatement Clearance testing. Testing of troughs is not a part of the proposed post-c leanup testing for R&R. This has been identified as a footnote to the report in the Executive Summary section.Final Report 60 Decem ber 28, 2005

9.0 QUALITY ASSURA NCE This study featured a

thorough and rigorous quality assurance process. This process was em bo di ed in tw o k ey c om po ne nt s o f t he st ud y: 1) The Qu

ality Assurance Proje ct Plan (Q APP) - The QAPP is a formal doc

ument pre

pared in advance of the study , signed by a ll key personnel, a

nd includes the detailed instructions on performing the field study procedures. It ha s been incorporated in its entirety into the current study report as Appe

ndix A. Among its most important elements with regard to quality are:

• The key

staff working on

the study , their qu alifica tions, and their rol es.

• An objec tive for t he study accompa nied by a set of d ata qual ity o

bjective s to asses s this objective. These DQOs are included in Section 3.1 of this document and they form the basis of reporting the results of this study in Section 6.2.

• Specifications for procedures reg arding sample handling and custody as well as study document ation and record s.

• Detailed specification of the study design, the protocols to be completed, and the analy tical met hods to be e

mploy ed. Each of these

componen

ts have a lso been t horoug hly documented in the final report with study design and protocols in section 3.1 through 3.4, and 4.1. The analy

tical methods are discussed in section 5.1.

• Quality control proce dures including quality control samples as well as procedures for data review, validation, and verification. The re sults of the quality control samples are discussed in section 5.2.

• Procedures for data review, validation, and ve rification as well as the planned calcula tions of fi nal study estimate s. The re sults and d iscussion of same a

re provi ded in section 4.2 and throughout Section 6. 2) The Peer Review - An important final component to quality assurance for this study

was subjecting the results to a review by professionals of several different disciplines with experience in the field of lead hazard control and removal. This peer r eview is documented in Section 8 of the report.