Characterizing residential wood smoke at the neighbourhood scale: An evaluation of five communities in British Columbia.

The experience of residential wood burning becoming an increasingly popular space heating method due to rising energy costs and interest in renewable energy resources raises both air quality and public health concerns. This work demonstrates a novel method that incorporates mobile and fixed-site monitoring to characterize the spatial and temporal distribution of residential wood smoke and identify persistent wood smoke hot spots within five communities situated in north-western British Columbia. High density measurements were collected throughout the communities with an integrated nephelometer during evenings (November 2007 and April 2008) when wood smoke was expected to be prevalent. Gravimetric PM[subscript 2.5] samples were collected at the central monitoring station in each community (October 2007 - April 2009) and analyzed for PM[subscript 2.5], levoglucosan (wood smoke tracer), and light absorbance (black carbon indicator). Slash burning activity was also assessed as a potential confounder of residential wood smoke. Measurements at the central monitoring stations confirmed that wood smoke is a prevalent (levoglucosan/PM[subscript 2.5] = 0.06± 0.03) and consistent (levoglucosan-PM[subscript 2.5] r[subscript]spear = 0.78-0.92) source of PM[subscript 2.5] in the communities. Comparisons between the 2007-08 and 2008-09 heating seasons suggest residential wood smoke concentrations may be declining. Persistent wood smoke hotspots were identified via mobile monitoring with mean estimated PM[subscript 2.5] ranging 13-59 μg m⁻³ and maximum values > 200 μg m⁻³. The majority of these areas were associated with single family dwellings followed by housing types typically associated with lower socioeconomic statuses. Central monitoring stations were representative of seasonal average community-wide concentrations for heating season evenings.