1 WOODSMOKE SOURCE APPORTIONMENT AND HOME INFILTRATION STUDY IN THE RURAL ANNAPOLIS VALLEY, NOVA SCOTIA, CANADA. Air & Waste Management Association’s 103 rd Annual Conference, Calgary, June 22, 2010. Expert panel presentation and paper in the conference proceedings. Paper #142 Mark D. Gibson, 1 Tony J. Ward, 2 Amanda J. Wheeler, 3 Judy R. Guernsey, 1 Matt P. Seaboyer, 1 Patrick Bazinet, 1 Gavin H. King, 1 Neil K. Brewster, 1 James Kuchta, 1 Ryan Potter, 1 Dave M. Stieb 4 1 Atlantic RURAL Centre, Community Health and Epidemiology, 5790 University Avenue, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 1V7. 2 Center for Environmental Health Sciences, 32 Campus Drive Missoula, University of Montana, Missoula, Montana, USA. 59812 3 Air Health Science Division, Health Canada, 269 Laurier Avenue West, Ottawa, Ontario, Canada. K1A OK9 4 Healthy Environments and Consumer Safety Branch, Health Canada, 269 Laurier Avenue West, Ottawa, Ontario, Canada. K1A OK9 INTRODUCTION Woodsmoke has recently received increasing attention as an important source of particulate matter, particularly in rural areas. 1-7 Indoor woodstoves and outdoor wood boilers are widely used in the Annapolis Valley, in rural Nova Scotia, and the area’s topography is conducive to trapping emissions especially during thermal inversions (typically 2 to 5 per winter). In an effort to quantify the impact of these factors on local air quality, the source contribution of residential wood burning to ambient PM 2.5 at one fixed site on the Annapolis Valley floor was determined during the winters of 2008/2009 (phase 1) and again in 2009/10 (phase 2). Running concurrently with the PM 2.5 ambient monitoring in 2009/10 was an investigation of woodsmoke home infiltration into 30 homes, together with an evaluation of the effectiveness of high efficiency particle air (HEPA) cleaners at reducing indoor PM 2.5 concentrations (phase 2). EXPERIMNTAL METHODS