Near-Field Variability of Residential Woodsmoke Concentrations

Abstract

In many regions, wood combustion is a significant source of wintertime aerosols. However, since wood combustion sources are interspersed within neighborhoods, near-field concentration variability has the potential to cause large variations in the exposure levels between residents over a relatively small area. This field study compared filter samples and aethalometer measurements of black carbon concentration within a 1 km 2 study region with no significant aerosol sources except wood combustion. Sampling occurred on 15 nights over two winter seasons in a small California coastal town. Even over the small distances in the study area, large spatial and temporal variations were observed. Measured black carbon concentrations varied by as much as a factor of 10 over a 12-hour night-time period. The spatial variability was non-random, with the highest location in the study area experiencing 4 times the average concentration within the neighborhood, when averaged over all sample periods. The results of this study indicate that within neighborhoods with residential wood combustion sources using an average concentration for a region to predict exposure may significantly undervalue the exposure of some residents and overvalue the exposure for others.

Accurate, Low Cost PM2.5 Measurements Demonstrate the Large Spatial Variation in Wood Smoke Pollution in Regional Australia and Improve Modeling and Estimates of Health Costs

“…Figure S3 provides additional comparisons of daily average PM 2. 5 at two sites in central Sydney (Rozelle and Macquarie Park), the two Hunter Valley towns with NSWGov monitoring stations, together with TEOM and calibrated PA measurements at the Armidale NSWGov site and at Armidale residential areas Res1_S and Res1_E. The difference between TEOM and PA measurements is almost negligible compared with the much greater spatial variation, indicating that calibrated PA PM 2.5 measurements are much more accurate than measurements from expensive equipment located a few hundred meters away.…”

“…Otherwise the models can be subject to considerable bias [3] leading to inaccurate results. One difficulty is that DWH pollution has considerable spatial and temporal variation [4,5] and the locations of some current fixed monitors were chosen to measure traffic pollution [6] and therefore provide inaccurate estimates of population exposure. Car-based night-time monitoring (using optical instruments calibrated by comparison with official government or other accredited PM 2.5 data) was used by some researchers to monitor spatial variation [4,[7][8][9].…”

Infiltration of Black Carbon Particles from Residential Woodsmoke into Nearby Homes

“…For this study, 12 hours integrated filter samples were taken simultaneously indoors and directly outdoors at four different residences on 6 nights during the winter. This sampling occurred in conjunction with an outdoor study of residential woodsmoke described by Thatcher et al [13]. The four homes were all located within the 1 km 2 study region and were detached single family residences which were constructed in the 1980s and 90s.…”

“…In addition, the study area was surveyed using an infrared camera to determine which homes were actively using their chimneys. This study was performed in conjunction with a study of variability of outdoor woodsmoke concentrations within a residential neighborhood [13].…”

“…The average AAE for the indoor filters was 2.6 ± 0.7 and the average for the outdoor samples was 2.2 ± 0.8 indicating that woodsmoke was the dominant particle source for both the indoor and outdoor samples. In addition, analysis showed that black carbon concentration performed as well as any of the other surrogate measurements of woodsmoke particle concentration [13]. As a result, the analysis of the indoor and outdoor woodsmoke concentrations within the study area was performed using black carbon (BC) concentrations based on attenuation at 880 nm to represent the amount of woodsmoke at the sampling locations.…”