1

2

3

PresentationSafety Health impacts

Carbon monoxideParticulate Matter (PM)

Wood stoves

4

SafetyPerform regular maintenanceAvoid installing unvented (or "vent-free”) heating

appliancesConsider using only sealed-combustion, induced draft, or

power-vented furnaces, boilers, and water heatersFor gas range, use properly sized range hood fanAfter installation of combustion and/or ventilation

equipment, test for proper functioningVent clothes dryers to outsideInstall a carbon monoxide alarm (state law)

5

Silent Killer: Carbon Monoxide (CO)

6

Combustion-Appliance Backdrafting

DepressurizationExhaust ventsWind

Pulls air back down chimney or flue

www.epa.gov/iaq/homes/hip-backdrafting.html

7

CO Levels (General Guidelines)

0-9 ppm No significant health risk 35-50 ppm Exposure – chronic: headaches, nausea,

tired

Most Detectors Start Alarming 50-70 ppm Exposure - 2-3 hours: flu-like symptoms,

headache, nausea

70-200 ppm Exposure - 1 hour: dizziness, fatigue, vomiting

200-800 ppm Exposure – Minutes: unconsciousness, brain damage, DEATH

8

How CO attacks… Red blood cells

prefer CO to oxygen If enough CO in air,

CO replaces oxygen in blood

Blocks oxygen from getting into body, damaging tissues and potentially causing death

9

Common Sources of CO Blocked flue, chimney, vent pipes Rusted/cracked furnace heat exchanger Idling engine in attached garage Back-drafting, spillage Mal-adjusted fuel-fired space heater Unvented use of BBQ/charcoal indoors Gas stoves and ranges, water heaters Outdoor combustion exhaust near

door/vent/window

10

Particulate Matter (PM)Eye, nose, throat, lung irritation

Bronchitis, allergies, asthma, respiratory and ear infections, cardiovascular conditions…

Sooting from appliancesGhosting on walls/ceilingWhat is adhered-to particle?

11

Wood Stoves are a Source of PMWood stove changeouts (ambient and indoor)Filtration units (indoor)Best-burn practices (ambient and indoor).Wood banks (ambient)

12

Temperature Inversions

Valley Locations

13

14

Wood Stoves (cont.)In rural Northern Rocky Mountains of western MT,

PM2.5 is major ambient air pollution issue (especially during winter

Majority of wintertime PM2.5 comes from wood stoves (56 – 77%)

Ward T, Lange T. The impact of wood smoke on ambient PM2.5 in northern Rocky Mountain valley communities. Environ Pollut. 2010 Mar;158(3):723-9.

Wood-smoke can also be a local problem anywhere

15

So, what can be done?Wood stove changeouts have

become a common tool targeting

ambient wood smoke PM2.5

A good example is Libby, MT

16

Wood Stove Changeout

Old stove40-60 g smoke/hr

EPA-certified stove2-5 g smoke/hr

17

18

Key Finding - Libby

A major woodstove change-out can be effective in

reducing ambient levels of PM2.5

19

20

21

22

How does a wood stove changeout impact indoor air quality?

Old stove40-60 g smoke/hr

EPA-certified stove2-5 g smoke/hr

23

2006/2007 Libby Residential PM2.5 Sampling Program

Sampling focused on 20 homes containing wood stoves

24-hour PM2.5 sampling

Pre-changeout period (Oct/Nov 2006)

Post-changeout (Dec 2006 – Feb 2007)

Goal of program: evaluate impact of this “intervention” on indoor air quality within home

24

Libby PM2.5 Mass Results: Pre- and Post-Changeout

Pre-changeout avg PM2.5: 53.4 μg/m3 Post-changeout avg PM2.5: 15.0 μg/m3

0

20

40

60

80

100

120

140

Home 1

Home 3

Home 5

Home 6

Home 7

Home 8

Home 9

Home 1

0

Home 1

1

Home 1

2

Home 1

3

Home 1

4

Home 1

5

Home 1

7

Home 1

8

Home 2

0

PM

2.5

Con

cen

trat

ion

(u

g/m

3 )

Pre Avg PM2.5

Post Avg PM2.5

25

Results of Multi-Winter Residential Study

Overall reductions following the wood stove

changeout observed in 16 of 21 homes

26

27

Nez Perce Wood Stove Changeout

Conducted during winters of 2006/2007, 2007/2008, and 2008/2009

Kamiah and Lapwai, Idaho, on Nez Perce Reservation

16 homes

28

0.0

20.0

40.0

60.0

80.0

100.0

120.0

140.0

160.0

180.0

200.0

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Home

PM

2.5

Con

cent

rati

on (

ug/m

3 )

Avg PM2.5 Pre (ug/m3)

Avg PM2.5 Post (ug/m3)

Pre-changeout avg PM2.5: 43.1 μg/m3 Post-changeout avg PM2.5: 126.0 μg/m3

~278% PM2.5

increase

29

0.0

20.0

40.0

60.0

80.0

100.0

120.0

140.0

160.0

180.0

200.0

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Home

PM

2.5

Con

cent

rati

on (

ug/m

3 )

Avg PM2.5 Pre (ug/m3)

Avg PM2.5 Post (ug/m3)

Pre-changeout avg PM2.5: 43.1 μg/m3 Post-changeout avg PM2.5: 126.0 μg/m3

~278% PM2.5

increase

30

0.0

20.0

40.0

60.0

80.0

100.0

120.0

140.0

Pre Post 1 Post 2

Sampling Event

PM

2.5

Co

nce

ntr

atio

n (

ug

/m3 )

Home 2

Home 6

Home 11

Home 13

PM2.5 Mass (µg/m3) Measured in Homes Following Outreach/Education.Ward, T.J., Boulafentis, J., Simpson, J., Hester, C., Moliga, T., Warden, K., and Noonan, C.W., 2011. Results of the Nez Perce woodstove changeout program, Science of the Total Environment, 409, 664-670.

31

Wood Stove Changeouts

Effective in reducing ambient PM2.5

Expensive (~$1500 - $4500)Learning curve for occupantsResults can be variable for indoor air

32True HEPA Filters 99.97% Removal

33

Randomized Trial for Indoor Smoke (ARTIS)

5-year, NIEHS-funded study

Primary aim of study: assess impact on quality of life among asthmatic children following interventions that reduce in-home wood smoke PM exposures

34

Preliminary Results of ARTIS Interventions

59% Reduction

35

Use of Best-Burn PracticesEducation coupled with use of inexpensive tools

Burn at proper temperatures (thermometer)

270-460 °F is optimal

36

Use of Best-Burn Practices (cont.)Burn dry, seasoned wood (moisture meter)

<20% moisture is optimal

37

Use of Best-Burn Practices (cont.)

Don’t burn trash, etc.Stove maintenance (ash cleaning, clean out chimneys,

etc.)

EPA Burn Wise Programhttp://www.epa.gov/burnwise/

38

Summary – ChangeoutsWood stoves are a significant source of PM2.5 in

both ambient and indoor environments

Wood stove changeouts can be effective in

reducing ambient wintertime PM2.5 – results are

more variable indoors

Changeouts are expensive

Training and education on new stoves essential

39

Summary – Filtration Units

Filtration units are consistently effective in improving indoor

air in homes with wood stoves

Improves indoor air quality by ~60%, but does nothing for

outdoors

Electricity costs are a concern and units can be noisy

Require regular filter change-outs

40

Summary – Burning Practices

Best-burn practices are inexpensive and sustainable strategies

Education, outreach, and training are critical

41

Summary – Other Considerations

Each intervention should be culturally and regionally appropriate

Interventions need to be sustainable