Air Quality Impacts of Smoke from Hazard Reduction Burns and Domestic Wood Heating in Western Sydney

Abstract

Air quality was measured in Auburn, a western suburb of Sydney, Australia, for approximately eighteen months during 2016 and 2017. A long open-path infrared spectrometer sampled path-averaged concentrations of several gaseous species, while other pollutants such as PM 2.5 and PM 10 were sampled by a mobile air quality station. The measurement site was impacted by a number of indoor wood-heating smoke events during cold winter nights as well as some major smoke events from hazard reduction burning in the spring of 2017. In this paper we compare the atmospheric composition during these different smoke pollution events and assess the relative overall impact on air quality from domestic wood-heaters and prescribed forest fires during the campaign. No significant differences in the composition of smoke from these two sources were identified in this study. Despite the hazard reduction burning events causing worse peak pollution levels, we find that the overall exposure to air toxins was greater from domestic wood-heaters due to their higher frequency and total duration. Our results suggest that policy-makers should place a greater focus on reducing wood-smoke pollution in Sydney and on communicating the issue to the public.

A Clean Air Plan for Sydney: An Overview of the Special Issue on Air Quality in New South Wales

“…During the CAUL measurement campaign at Auburn, all the major pollution events were associated with fires [130,157], reinforcing previous findings that fires (both wild and prescribed) are responsible for most of the worst air quality events in Sydney [51,82]. The new NEPM excludes hazard reduction burns (incorrectly assigning them to natural episodes) [7].…”

“…These will exacerbate the health impacts of exposure to smoke from the legislated pollutants. The chemical composition of smoke is very similar, regardless of whether the source is bushfires or domestic wood-heaters [157]. Wood-heaters are a significant contribution to human sources of PM 2.5 , as discussed earlier [130,148], and measurements made during the CAUL Auburn campaign, established that the overall exposure to heightened pollution levels from smoke from domestic wood-heaters in Auburn was greater than from bushfires, despite five major bushfire pollution events during spring 2017 [157].…”

“…Pollution from wood smoke contains a number of additional chemicals (such as formaldehyde and ammonia) that are known human toxins [157]. These will exacerbate the health impacts of exposure to smoke from the legislated pollutants.…”

Understanding Spatial Variability of Air Quality in Sydney: Part 1—A Suburban Balcony Case Study

“…Reduced February and March concentrations at Auburn may be an artefact of a period of reduced measurements due to technical difficulties. All sites show a winter maximum, likely attributable to combustion heating emissions [33]. A smaller, secondary maximum in December-January is due to more active secondary photochemical particle formation processes (partially temperature and oxidant driven) [52].…”

“…The OP-FTIR system, which can measure infrared active gases such as CO, NH 3 , N 2 O and CH 4 , has previously been deployed for agricultural [28][29][30] and biomass burning [31,32] emissions estimates. Details of the main findings from the OP-FTIR during WASPSS, which relate to vehicle ammonia emissions and episodes of significant smoke pollution, are presented in two separate papers [33,34].…”