Wood smoke black carbon from Indigenous traditional cultural activities in a subarctic Cree community

Abstract

Indoor concentrations of black carbon (BC) were measured when wood was burned for traditional cultural activities in a study in a Cree community located in subarctic Canada. The study also included an intervention using a propane-fuelled heater to mitigate in situ BC. Mass concentrations of BC were measured in a game-smoking tent for 39 days and in hunting cabins on the west coast of James Bay, Canada, for 8 days. Five-minute averaged BC mass concentration (N = 12,319) data were recorded and assessed using optimised noise-reduction averaging. Mean BC mass concentrations were lower in hunting cabins (mean = 8.25 micrograms per cubic metre (µg m^-3)) and higher in the game-smoking tent (mean = 15.46 µg m^-3). However, excessive BC peaks were recorded in the game-smoking tent (maximum = 3076.71 µg m^-3) when the fire was stoked or loaded. The intervention with the propane heater in a hunting cabin yielded a 90% reduction in measured BC mass concentrations. We do not presume that exposure to BC is of concern in hunting cabins with appropriate wood-burning appliances that are well-sealed and vent outside. In game-smoking tents, we advise that persons take intermittent breaks outside of the tent for fresh air.

Keywords: Cree; Indigenous; James Bay; Wood; black carbon; indoors; smoke.

Figure 1.

Fort Albany First Nation, James Bay, Ontario, Canada.

Figure 2.

Clockwise from top left: Figure 2(a). Geese being smoked over a fire in a traditional game-smoking tent. Smoke is clearly visible towards the top of the photo. Figure 2(b). A wood burning wood stove made of a steel 45-gallon drum in a hunting cabin. Figure 2(c). A chimney flue exiting a hunting cabin. Photo permissions: R. Moriarity (2a) and M.Wilton (2b and c).

Figure 3.

Wood smoke BC mass concentration boxplots. Mass concentrations of BC (log₁₀ µg m⁻³) of the game-smoking tent (TCA₁) and the hunting cabins (TCA₂) with seasonal or site means (red circle). The width of the boxes varies by sample size, where a larger box represents a larger sample size and vice versa.

Figure 4.

Wood smoke BC mass concentrations during TCA₁. Non-consecutive time-series plot of mass concentrations of BC over the seasonal data collection periods in the game-smoking tent. The change in season is noted by the break in the axis. The seasonally adjusted data (blue line) and moving average (dashed red line) are included to indicate the trend of the data.

Figure 5.

Wood smoke BC mass concentrations during TCA₂. Time-series plot of mass concentrations of BC over the period from April 17 to 25, 2016 at site I (top plot), site II (middle plot) and site III (bottom plot). The propane interventions at site I are noted by the red dashed-line boxes.

Figure 6.

Wood smoke BC mass concentrations boxplots before and during propane intervention (TCA_2i). Mass concentrations of BC (log₁₀ µg m⁻³) in hunting cabin site I while burning wood for heat (grey box) and when the propane-fuelled heater was introduced (blue box). The mean BC mass concentrations are indicated by a red circle. Sample size varies by width of box.