Indoor and Outdoor Air Indoor and Outdoor Air Pollutants, AQI Values, and Pollutants, AQI Values, and

Childhood AsthmaChildhood Asthma

John L Parker, MSPHJohn L Parker, MSPHJohn M. John M. VeranthVeranth, , Ph.DPh.DUniversity of Utah University of Utah

And Many CollaboratorsAnd Many Collaborators

Study BasisStudy BasisPediatrician & School Official Question:Does keeping children indoors on high air pollutant days protect health?• Utah Div. Of Air Quality issues heath advisories

based on Air Quality Index (AQI) and coordinates with the Utah Dept. Of Health and school districts

• Very little peer-reviewed literature supporting the “Stay indoors on high air pollution days”recommendation

RelevanceRelevance• Increasing childhood asthma.• Keeping children inside has health, behavioral, and

social consequences.

Study MethodsStudy Methods

• Indoor and Outdoor Air Quality Monitoring:– Particulate size distribution, mass and composition– Volatile Organic Compounds (VOCs) concentration

and composition• Clinical: Spirometery before and after recess

and health questionaire.

Study Site Study Site -- Hawthorne Hawthorne Elementary School, SLC UTElementary School, SLC UT

Air Quality IndexAir Quality Index

• AQI is composed of:– Ground-level Ozone– Particle pollution

• PM2.5, fine particulates• PM10, coarse particulates

– Carbon monoxide– Sulfur dioxide– Nitrogen dioxide

– Highest value becomes the reported AQI

– Measurements recorded twice daily (morning/evening)

– Designed to be easy method to inform public of pollution levels

– AQI based on science, consensus and opinion

Air Quality Index ValuesAir Quality Index Values• No really serious air pollution episodes

0

25

50

75

100

125

1/25/2

006

1/27/2

006

1/29/2

006

1/31/2

006

2/2/20

062/4

/2006

2/6/20

062/8

/2006

2/10/2

006

2/12/2

006

2/14/2

006

2/16/2

006

2/18/2

006

2/20/2

006

2/22/2

006

2/24/2

006

2/26/2

006

2/28/2

006

Air

Qua

lity

Inde

x

AQI - AM AQI - PM

PM 2.5 Vs. AQIPM 2.5 Vs. AQI

• Health recommendations:– Green – Good– Yellow – Moderate– Orange – Sensitive– Red – Unhealthy– Purple – Very

Unhealthy– Maroon - Hazardous

050

100150200250300350400450500

0 100 200 300 400 500

Air Quality Index

PM 2

.5 (u

g/m

^3)

HazardousHazardousVery Very UnhealthyUnhealthy

Unhealthy

Unhealthy

SensitiveSensitiveM

oderateM

oderateG

oodG

ood

ParticulatesParticulates

• Measured Indoors/Outdoors with:– GRIMM aerosol spectrometer model 1.108

• Continuous measurements on 15 bins (0.3 - 20+ µm)– Tapered Element Oscillating Microbalance (TEOM)

• EPA approved• Used for determining correction factor for Grimm PM 3

– Speciation performed:• Indoor samples taken weekly for PM 10 • Outdoor samples taken every 3 days for PM 2.5 • Results averaged daily over study period

Particulate ResultsParticulate ResultsIndoor and Outdoor PollutionIndoor and Outdoor Pollution

Outdoor AirAvg. of 5 Least and Most Polluted days

0.00

5.00

10.00

15.00

20.00

0.1 1 10

Particle Size in Microns

Estim

ated

Mas

s (m

icro

gram

s/m

^3)

Least Polluted Most Polluted

Indoor AirAvg. of 5 Least and Most Polluted days

0.00

0.50

1.00

1.50

2.00

2.50

0.1 1 10

Particle Size in Microns

Estim

ated

Mas

s (m

icro

gram

s/m

^3)

Least Polluted Most Polluted

Least Polluted Most Polluted

Time Trend DataTime Trend Data0.3 to 0.4 Microns0.3 to 0.4 Microns

02

46

Est

. Mic

roG

ram

s of

Par

ticle

s pe

r m^3

of A

ir

1/25/06 09001/25/06 0900 1/29/06 12001/25/06 0900 1/29/06 1200 2/2/06 16001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 20001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 00001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 0000 2/15/06/04001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 0000 2/15/06/0400 2/19/06 08001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 0000 2/15/06/0400 2/19/06 0800 2/23/06 12001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 0000 2/15/06/0400 2/19/06 0800 2/23/06 1200 2/27/06 1600Date and Time

Mass Inside Mass Outside

Hourly Averages (0.3 to 0.4 Microns in Size)Hawthorne Particulates

Time Trend DataTime Trend Data4 to 5 Microns4 to 5 Microns

0.5

11.

5E

st. M

icro

Gra

ms

of P

artic

les

per m

^3 o

f Air

1/25/06 09001/25/06 0900 1/29/06 12001/25/06 0900 1/29/06 1200 2/2/06 16001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 20001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 00001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 0000 2/15/06/04001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 0000 2/15/06/0400 2/19/06 08001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 0000 2/15/06/0400 2/19/06 0800 2/23/06 12001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 0000 2/15/06/0400 2/19/06 0800 2/23/06 1200 2/27/06 1600Date and Time

Mass Inside Mass Outside

Hourly Averages (4 to 5 Microns in Size)Hawthorne Particulates

Time Trend DataTime Trend Data10 to 15 Microns10 to 15 Microns

01

23

4E

st. M

icro

Gra

ms

of P

artic

les

per m

^3 o

f Air

1/25/06 09001/25/06 0900 1/29/06 12001/25/06 0900 1/29/06 1200 2/2/06 16001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 20001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 00001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 0000 2/15/06/04001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 0000 2/15/06/0400 2/19/06 08001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 0000 2/15/06/0400 2/19/06 0800 2/23/06 12001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 0000 2/15/06/0400 2/19/06 0800 2/23/06 1200 2/27/06 1600Date and Time

Inside Mass Outside Mass

Hourly Averages (10 to 15 Microns in Size)Hawthorne Particulates

Time Trend DataTime Trend Data0

24

6E

st. M

icro

Gra

ms

of P

artic

les

per m

^3 o

f Air

1/25/06 09001/25/06 0900 1/29/06 12001/25/06 0900 1/29/06 1200 2/2/06 16001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 20001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 00001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 0000 2/15/06/04001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 0000 2/15/06/0400 2/19/06 08001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 0000 2/15/06/0400 2/19/06 0800 2/23/06 12001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 0000 2/15/06/0400 2/19/06 0800 2/23/06 1200 2/27/06 1600Date and Time

Mass Inside Mass Outside

Hourly Averages (0.3 to 0.4 Microns in Size)Hawthorne Particulates

0.5

11.

5E

st. M

icro

Gra

ms

of P

artic

les

per m

^3 o

f Air

1/25/06 09001/25/06 0900 1/29/06 12001/25/06 0900 1/29/06 1200 2/2/06 16001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 20001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 00001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 0000 2/15/06/04001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 0000 2/15/06/0400 2/19/06 08001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 0000 2/15/06/0400 2/19/06 0800 2/23/06 12001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 0000 2/15/06/0400 2/19/06 0800 2/23/06 1200 2/27/06 1600Date and Time

Mass Inside Mass Outside

Hourly Averages (4 to 5 Microns in Size)Hawthorne Particulates

01

23

4E

st. M

icro

Gra

ms

of P

artic

les

per m

^3 o

f Air

1/25/06 09001/25/06 0900 1/29/06 12001/25/06 0900 1/29/06 1200 2/2/06 16001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 20001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 00001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 0000 2/15/06/04001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 0000 2/15/06/0400 2/19/06 08001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 0000 2/15/06/0400 2/19/06 0800 2/23/06 12001/25/06 0900 1/29/06 1200 2/2/06 1600 2/6/06 2000 2/11/06 0000 2/15/06/0400 2/19/06 0800 2/23/06 1200 2/27/06 1600Date and Time

Inside Mass Outside Mass

Hourly Averages (10 to 15 Microns in Size)Hawthorne Particulates

Low penetration of outdoor submicron particles indoors. Clear school-daypeaks in 10µm PM are observed indoors.

Indoor Air Indoor Air –– Time AverageTime Average

0:00

-1:0

0

2:00

-3:0

0

4:00

-5:0

0

6:00

-7:0

0

8:00

-9:0

0

10:0

0-11

:00

12:0

0-13

:00

14:0

0-15

:00

16:0

0-17

:00

18:0

0-19

:00

20:0

0-21

:00

22:0

0-23

:00

0.3-0.4 µm

0.5-0.65 µm0.80-1.0 µm

1.6-2.0 µm3.0-4.0 µm

5.0-7.5 µm10-15 µm0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

Mas

s (µ

g/m

3)

Outdoor Air Outdoor Air –– Time AverageTime Average

0:00

-1:0

0

2:00

-3:0

0

4:00

-5:0

0

6:00

-7:0

0

8:00

-9:0

0

10:0

0-11

:00

12:0

0-13

:00

14:0

0-15

:00

16:0

0-17

:00

18:0

0-19

:00

20:0

0-21

:00

22:0

0-23

:00

10-15 µm

4.0-5.0 µm

1.6-2.0 µm

0.65 -0.8 µm

0.3-0.4 µm

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

Mas

s (µ

g/m

3)

0

2

4

6

8

0.1 1 10Particle Size in Microns

Estim

ated

Mas

s (m

icro

gram

s/m

^3)

Indoor Outdoor

Particulate ResultsParticulate ResultsStudy Average with SpeciationStudy Average with Speciation

Indoor Outdoor

AmmoniumNitrateElemental CarbonOrganic CarbonAluminumIronSilicon

Outdoor PM 2.5 Indoor PM 10

020

4060

80

0 50 100 150GRIMM Outdoor Mass (micrograms/m^3)

TEOM Outdoor Mass (micrograms/m^3) Fitted values

Particulate ResultsParticulate ResultsTEOM vs. GRIMMTEOM vs. GRIMM

05

1015

0 5 10 15 20GRIMM Indoor Mass (micrograms/m^3)

TEOM Indoor Mass (micrograms/m^3) Fitted values

Indoory = 0.59x - 0.172R2 = 0.51

Outdoory = 0.56x + 2.83R2 = 0.76

TEO

M F

DM

S M

ass

(ug/

m3 )

TEO

M M

ass

(ug/

m3 )

Particulate SummaryParticulate Summary

• Larger particles indoors; Smaller outdoors• Outdoor submicron particulates penetrating

indoors• Study particulate average composition:

– Outdoor PM 2.5 was primarily nitrate aerosols with organic carbon and ammonium

– Indoor PM 10 was primarily organic aerosols with some elemental carbon

VOCsVOCs

• 3 vacuum canister sample pairs (indoor/outdoor) – 2 sample pairs taken during low AQI days (AQI

<50)– 1 sample pair taken during elevated AQI day

(AQI > 100)• Analyzed using EPA method TO 17

– 51 targeted + 30 tentatively identified compounds

Volatile Organic ChemicalsVolatile Organic Chemicals

February 10, 2006 VOCs - AQI 101

05

1015202530

Benze

ne

Toluen

e

Ethylbe

nzen

e

m, p-X

ylene

o-Xyle

neVOC

Con

cent

ratio

n (u

g/m

^3)

Inside Outside

February 27, 2006 VOCs - AQI 32

02468

10121416

Benze

ne

Toluen

e

Ethylbe

nzen

e

m, p-X

ylene

o-Xyle

neVOC

Con

cent

ratio

n (u

g/m

^3)

Inside Outside

•VOCs appear to be from indoor sources•No obvious relationship to outdoor pollution

Low Air Pollution High Air Pollution

Study ConclusionsStudy Conclusions

Is Staying Indoors Protective?Is Staying Indoors Protective?• Yes:

– Overall PM is less indoors than outdoors – Indoor school air is protective of submicron sized

particles• Indoor pollutant levels include higher levels of

VOCs– Levels not hazardous, just higher than outdoors– Association of low level VOCs not well understood

• Possible contributing factors to chronic effects such as asthma

Study ConclusionsStudy ConclusionsIndoor Air QualityIndoor Air Quality

• Indoor and outdoor environments differ• Larger indoor particles generated by human

activity• Submicron particles are infiltrating indoors, but

at considerably lower concentrations • VOCs generally present in higher

concentrations indoors than outdoors

AcknowledgementsAcknowledgements

• RR Larson, PhD• EM Wood, MD• HS Kim, PhD• John Veranth, PhD • N Frei, MD• K Buchi, MD• G Warwick, MS• S Packham, PhD• K Perry, PhD• G Smith• R Dalley• B Allen• L Chuy

• In kind support – State of Utah Department of

Environmental Quality, Air Quality Division

– Salt Lake School District– Desert Research Institute – DataChem Laboratories – Rocky Mountain Center for

Occupational and Environmental Health

Financial Support•Primary Children's Medical Center Foundation•NIEHS K25 ES11281