Intervention Strategies for Woodstove Homes Tony Ward, Ph.D. The University of Montana Center for Environmental Health Sciences June 16, 2011

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Source:

Ambient PM

EPA 24-Hour PM 2.5 Nonattainment Areas *As of Aug 2010 National Ambient Air Quality Standard (NAAQS): Annual, 15 μg/m 3 ; 24-hr, 35 μg/m 3.

Woodstoves

Chemical Mass Balance (CMB) PM 2.5 Source Apportionment Computer modeling to determine what the sources of PM 2.5 are in the airsheds. 1) Collect PM 2.5 air samples. 2) Analyze the air samples for chemical species. 3) Use an EPA computer model (CMB) to apportion the sources.

Air Samplers

Sources of Hamilton PM 2.5 Winter 2007/2008 Average PM 2.5 : 11.0 μ g/m 3 11/2/07 – 3/1/08

Sources of Butte PM 2.5 Winter 2007/2008 Average PM 2.5 : 13.5 μ g/m 3 11/8/07 – 3/1/08

Sources of Helena PM 2.5 Winter 2007/2008 Average PM 2.5 : 9.0 μ g/m 3 11/2/07 – 3/1/08

Sources of Kalispell PM 2.5 Winter 2008/2009 Average PM 2.5 : 9.0 μ g/m 3 11/2/07 – 3/1/08 Average PM 2.5 : 10.1 μ g/m 3 11/2/08 – 2/24/09

Fairbanks State Building CMB Results (November 11, 2008 – April 7, 2009)

Fairbanks - North Pole CMB Results (January 25, 2009 – April 7, 2009)

Woodstoves In the rural Northern Rocky Mountains of western Montana, PM 2.5 is the major ambient air pollution issue (especially during the winter months). The majority of the wintertime PM 2.5 comes from woodstoves (56 – 77%). Ward T, Lange T. The impact of wood smoke on ambient PM2.5 in northern Rocky Mountain valley communities. Environ Pollut Mar;158(3):723-9.

Woodstove Changeouts Woodstove changeouts are becoming a common tool targeting ambient woodsmoke PM 2.5. A good example is Libby, Montana.

Woodstove Changeout Old stove g smoke/hr EPA-certified stove 2-5 g smoke/hr

PM 2.5 Nonattainment Areas (2003) NAAQS: Annual, 15 μg/m 3 ; 24-hr was 65 μg/m 3.

PM 2.5 Seasonal Trends

Winter 2003/2004 Libby, Montana Sources of PM 2.5 Ward, T.J., Rinehart, L.R., and Lange, T., The 2003/2004 Libby, Montana PM2.5 source apportionment research study, Aerosol Science and Technology, 40:

Temperature Inversions

Woodstoves

Libby Woodstove Changeout Program Funding provided by Montana DEQ, EPA, and HPBA.

Libby Woodstove Changeout Program Nearly 1,200 old woodstoves were changed out, modified, or surrendered between 2005 and 2008.

Wood Stove Change-out Program: A Natural Experiment Conduct prospective multi-year study to assess changes in woodsmoke PM 2.5 and impact on health of school children following the intervention. 1.Monitor changes in ambient PM Monitor changes in school indoor PM Evaluate the change in residential indoor PM 2.5 following a changeout. 4.Track changes in reporting of symptoms and illness-related absences among students.

PM 2.5 in Libby and NAAQS

Key Finding - Libby A large woodstove changeout can be effective in reducing ambient levels of PM 2.5. Bergauff, M.A., Ward, T.J., Noonan, C.W., and Palmer C.P The effect of a woodstove changeout on ambient levels of PM 2.5 and chemical tracers for woodsmoke in Libby, Montana. Atmospheric Environment, 43, Ward, T.J., Palmer, C.P., Houck, J.E., Navidi, W.C., Geinitz, S., and Noonan, C.W., A community woodstove changeout and impact on ambient concentrations of polycyclic aromatic hydrocarbons. Environmental Science & Technology, 43(14), 5345–5350. Ward, T. J., Palmer, C. P., and Noonan, C. W., 2010, PM 2.5 source apportionment following a large woodstove changeout program in Libby, Montana. Journal of the Air and Waste Management Association, 60:

What about the impact of a woodstove changeout on indoor levels of PM 2.5 ? 1) Libby, Montana. 2) Nez Perce Woodstove Changeout Program.

Exposure Assessment Within Homes

15:22 19:53 06:30 Start Sampling: 14:00 End Sampling: 14:00 Avg = μg/m 3 Before Changeout

2006/2007 Libby Residential PM 2.5 Sampling Program Sampling focused on 20 homes containing woodstoves. 24-hour PM 2.5 sampling Pre-changeout period (Oct/Nov 2006). Post-changeout (Dec 2006 – Feb 2007). The goal of the program was to evaluate the impact of this “intervention” on indoor air quality within the home.

Libby PM 2.5 Mass Results – Pre and Post Stove Changeout Pre-changeout avg PM 2.5 : 53.4 μg/m 3 Post-changeout avg PM 2.5 : 15.0 μg/m 3

PM 2.5 Maximum Spikes – Pre and Post Stove Changeout Pre-changeout spike avg: 434 μg/m 3 Post-changeout spike avg: 103 μg/m 3

Libby Residential Program, cont. Did the stove changeout work over time? Ward, T.J., Palmer, C., Bergauff, M., Hooper, K., and Noonan, C., Results of a residential indoor PM 2.5 sampling program before and after a woodstove changeout, Indoor Air, 18: 408–415.

Followup PM 2.5 Indoor Study Air sampling was conducted in a total of 26 woodstove homes. Five phases: Phase 1 = pre stove change, 2006/2007 winter. Phase 2 = post change, same winter. Phase 3 = post change, 2 nd 2007/2008 winter. Phase 4 = post change, 3 rd 2007/2008 winter. Phase 5 = post change, 4 th 2008/2009 winter.

Libby Residential Study (winters of 2006/ /2009 (3 winters) Pre-changeout avg PM 2.5 : 63.2 µg/m 3 Post-changeout avg PM 2.5 : 28.9 µg/m 3

Results of Multi-Winter Residential Study Overall reductions following the wood stove changeout were observed in 16 of 21 homes. High variability was observed for post-changeout sampling within some homes, but 14 of the 21 homes still had lower PM 2.5 concentrations for all post-changeout sampling compared to pre- changeout PM 2.5 concentrations.

Nez Perce Woodstove Changeout Program

Nez Perce Woodstove Changeout Conducted during the winters of 2006/2007, 2007/2008, and 2008/2009. Kamiah and Lapwai, Idaho on the Nez Perce Reservation. 16 homes.

Nez Perce Woodstove Changeout PM 2.5 Mass Results Pre-changeout avg PM 2.5 : 43.1 μg/m 3 Post-changeout avg PM 2.5 : μg/m 3 ~278% PM 2.5 increase

Importance of Training PM 2.5 Mass (µg/m 3 ) Measured in Homes Following Outreach/Education. Ward, T.J., Boulafentis, J., Simpson, J., Hester, C., Moliga, T., Warden, K., and Noonan, C.W., Results of the Nez Perce woodstove changeout program, Science of the Total Environment, 409,

Woodstove Changeouts Effective in reducing ambient PM 2.5. Expensive (~$ $4500). Learning curve. Results can be variable for indoor air.

Another Indoor Intervention - Filtration Units -

Avg ~50% PM 2.5 Reduction in Woodstove Homes

A Randomized Trial for Indoor Smoke (ARTIS) 5-year, NIEHS funded study. The Primary Aim of this study is to assess the impact on quality of life among asthmatic children following interventions that reduce in-home woodsmoke PM exposures.

Study Design: Randomized Trial Recruitment Randomization Group 1 (n=36) Group 2 (n=36) Group 3 (n=36) Winter #1: Baselines Exposure and Health Outcomes Measures Winter #2: Post-intervention Exposure and Health Outcomes Measures Tx1: EPA- Certified Woodstove Tx2: Active Air Filter Units In two rooms Tx3: Inactive Air Filter Units (Placebo) X

Health Outcome Measures PAQoL Peak flow Symptoms eNO Biol. samples –EBC –Urine Dr. Curtis Noonan

Indoor Air Sampling

ARTIS Preliminary Results

Summary Woodstoves are a significant source of PM 2.5 in both ambient and indoor environments. Woodstove changeouts can be effective in reducing ambient wintertime PM 2.5 – results are more variable indoors. Filtration units are consistently effective in improving indoor air in homes with woodstoves.

Acknowledgements Funding NIH Centers of Biomedical Research Excellence (p20- RR017670). Health Effects Institute (#4743-RFA04-4/06-4). NIEHS (1R01ES ; 3R01ES S1) Montana Department of Environmental Quality (DEQ). Alaska Department of Environmental Conservation (DEC, Barbara Trost and Jim Connor). EPA Region 10 (Mary Manous). Nez Perce ERWM (Johna Boulafentis and Julie Simpson). The 3M Corporation. Toyota USA Foundation.

Thank you. Tony Ward (406)