November 3, 2008Office of Research and DevelopmentNational Exposure Research Laboratory

Alan Vette, Sheng-Wei Wang, BJ George, Don Whitaker,Karen Oliver, Herb Jacumin, Jonathan Thornburg,

Charles Rodes and Ronald Williams

DEARS Exposure Relationships VOCs, EC and NO2

1Office of Research and DevelopmentNational Exposure Research Laboratory

Passive SamplersPassive Samplers

•

Diffusive samplers - 25 VOCs + NO2•

Aromatics/HCs (9)•

Halogenated HCs (16)•

Detection limits –VOCs ~ 50 pptv–NO2 ~ 5 ppbv

2Office of Research and DevelopmentNational Exposure Research Laboratory

VOCsVOCs Measured in DEARSMeasured in DEARS

Aromatics/HCsBenzeneTolueneEthylbenzenem,p-Xyleneo-Xylene1,3-Butadiene4-Ethyltoluene1,3,5-TrimethylbenzeneStyrene

Chlorinated Aromatics/HCsCarbon tetrachloride1,1-Dichloroethane1,2-Dichloroethane1,1,1-Trichloroethane1,1-Dichloroethylenecis-1,2-DichloroethyleneTrichloroethylenePerchloroethylene1,2-DichloropropaneChlorobenzenem-Dichlorobenzeneo-Dichlorobenzenep-Dichlorobenzene

FreonTrichlorofluoromethane (11)1,1,2-Trichloro-1,2,2-

trifluoroethane (113)1,2-Dichloro-1,1,2,2-

tetrafluoroethane (114)

3Office of Research and DevelopmentNational Exposure Research Laboratory

Benz

ene

Tolu

ene

Ethy

lben

zene

m,p

-Xyl

enes

o-Xy

lene

1,3-

Buta

dien

e

1,3,

5-Tr

imet

hylb

enze

ne

p-Et

hylto

luen

eSt

yren

e

Carb

on te

trach

lorid

e

cis-

1,2-

Dich

loro

ethy

lene

1,1-

Dich

loro

ethy

lene

1,1-

Dich

loro

etha

ne

1,2-

Dich

loro

etha

ne

1,2-

Dich

loro

prop

ane

1,1,

1-Tr

ichl

oroe

than

e

Tric

hlor

oeth

ylen

e

Perc

hlor

oeth

ylen

e

Chlo

robe

nzen

e

m-D

ichl

orob

enze

ne

o-Di

chlo

robe

nzen

e

p-Di

chlo

robe

nzen

eFr

eon-

11Fr

eon-

113

Freo

n-11

4NO

2EC

Sam

ples

> M

DL

(%)

0

20

40

60

80

100 PersonalIndoorOutdoorAmbient

4Office of Research and DevelopmentNational Exposure Research Laboratory

Benz

ene

Tolu

ene

Ethy

lben

zene

m,p

-Xyl

enes

o-Xy

lene

1,3-

Buta

dien

e

1,3,

5-Tr

imet

hylb

enze

ne

p-Et

hylto

luen

eSt

yren

e

Carb

on te

trach

lorid

e

cis-

1,2-

Dich

loro

ethy

lene

1,1-

Dich

loro

ethy

lene

1,1-

Dich

loro

etha

ne

1,2-

Dich

loro

etha

ne

1,2-

Dich

loro

prop

ane

1,1,

1-Tr

ichl

oroe

than

e

Tric

hlor

oeth

ylen

e

Perc

hlor

oeth

ylen

e

Chlo

robe

nzen

e

m-D

ichl

orob

enze

ne

o-Di

chlo

robe

nzen

e

p-Di

chlo

robe

nzen

eFr

eon-

11Fr

eon-

113

Freo

n-11

4NO

2EC

ICC

Dup

licat

e Sa

mpl

es

0.0

0.2

0.4

0.6

0.8

1.0

PersonalIndoorOutdoorAmbient

5Office of Research and DevelopmentNational Exposure Research Laboratory

Impact of Environmental Tobacco SmokeImpact of Environmental Tobacco Smoke

Toluene

μg m

-3

0

20

40

60

80m,p-Xylene

0

10

20

30

401,3-Butadiene

0

1

2

3

4

5

6

Non-ETS ImpactedETS Impacted

•

Indoor levels of VOCs associated with tobacco smoke•

ETS was measured using an optical technique on filter samples•

Samples were considered impacted by ETS when ETS levels exceeded 1.5 µg m-3

•

34% of personal and 21% of indoor samples contained ETS > 1.5 µg m-3

6Office of Research and DevelopmentNational Exposure Research Laboratory

Effect of Residential CharacteristicsEffect of Residential Characteristics

Pollutant Location Attached Garage

Painting (7 d prior)

Carpet (6 mo. Prior)

Construction (6 mo. Prior)

Linoleum (6 mo. Prior)

Gas Stove

Benzene Indoor 46 44 6 17

Personal 115 45

Toluene Indoor 48 51 37 14 66

Personal 38 36

Ethylbenzene Indoor 38 56 90 32 52

Personal 15 58 54

m,p-Xylenes Indoor 52 58 95 33 50

Personal 46 28 76 26

Perchloroethylene Indoor

Personal

NO2 Personal 34

EC Indoor

7Office of Research and DevelopmentNational Exposure Research Laboratory

Effect of Personal ActivitiesEffect of Personal Activities

Pollutant Location Gas space heater

Solvent usage

Candles or incense

Dryclean(7 d. prior)

Benzene Indoor -27Personal -36

Toluene Indoor 38 -30Personal -38

Ethylbenzene Indoor 64 -30Personal 118 -32

m,p-Xylenes Indoor 65Personal 10

Perchloroethylene Indoor 376Personal 645

NO2 Personal 114EC Indoor 121

8Office of Research and DevelopmentNational Exposure Research Laboratory Concentration (μg m-3)

0.01 0.1 1 10 100

Benzene

Toluene

Ethylbenzene

m,p-Xylene

o-Xylene

1,3-Butadiene

1,3,5-Trimethylbenzene

p-Ethyltoluene

Styrene

Carbon tetrachloride

1,1,1-Trichloroethane

Perchloroethylene

p-Dichlorobenzene

Freon-11

Freon-113

NO2

EC

PersonalIndoorOutdoorAmbient

9Office of Research and DevelopmentNational Exposure Research Laboratory

Benz

ene

Tolu

ene

Ethy

lben

zene

m,p

-Xyl

enes

o-Xy

lene

1,3-

Buta

dien

e

1,3,

5-Tr

imet

hylb

enze

nep-

Ethy

ltolu

ene

Styr

ene

Carb

on te

trach

lorid

e

1,1,

1-Tr

ichl

oroe

than

e

Perc

hlor

oeth

ylen

e

p-Di

chlo

robe

nzen

eFr

eon-

11Fr

eon-

113

NO2

EC

Indo

or/O

utdo

or R

atio

0.1

1

10

SummerWinter

10Office of Research and DevelopmentNational Exposure Research Laboratory

Benz

ene

Tolu

ene

Ethy

lben

zene

m,p

-Xyle

neo-

Xyle

ne1,

3-Bu

tadi

ene

1,3,

5-Tr

imet

hylb

enze

ne4-

Ethy

ltolu

ene

Styr

ene

Carb

on te

trach

lorid

e

1,1,

1-Tr

ichlo

roet

hane

Perc

hlor

oeth

ylene

p-Di

chlo

robe

nzen

eFr

eon-

11Fr

eon-

113

NO2

EC

Mix

ed m

odel

slo

pe o

r R2

0.0

0.2

0.4

0.6

0.8

1.0

1.2IndoorOutdoorAmbientIndoor R2 Outdoor R2

Ambient R2

•

Mixed models – account for repeated measures

•

Exposures related to indoor, outdoor and sometimes ambient

•

Slopes (agreement): I > O > A

Personal Exposure RelationshipsPersonal Exposure Relationships Log Transformed DataLog Transformed Data

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Effective Distance from RoadwayEffective Distance from Roadway

Perpendicular Distance

12Office of Research and DevelopmentNational Exposure Research Laboratory

Effective Distance from RoadwayEffective Distance from Roadway

Nor

mal

ized

Con

cent

ratio

n(R

atio

of o

utdo

or:c

entr

alsi

te)

Ethylbenzene

Effective Distance (m)

m,p-Xylenes m,p-Xylenes

Ethylbenzene

Perpendicular Distance (m)

13Office of Research and DevelopmentNational Exposure Research Laboratory

ConclusionsConclusions

•

Carbopack-X passive tubes – robust and reliable method to measure VOCs

•

ETS found in 21% of indoor air and 34% of personal exposure samples

•

Residential characteristics and personal activities affect indoor and personal exposures

•

Significant spatial and temporal variability in MSATs– Impact of sources (EMA) and locations (I, O, A)

•

Personal exposures to MSATs– Indoor > Outdoor > Ambient

14Office of Research and DevelopmentNational Exposure Research Laboratory

Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

The U.S. Environmental Protection Agency through its Office of Research and Development funded and conducted the research described here through contract 68-D-00-012 with RTI International, EP-D-04-068 to Battelle Columbus Laboratory, 68-D-00-206 and EP-05-D-065 to Alion Science and Technology.

DisclaimerDisclaimer