Bushfire Smoke Research Articles

Effects of PM2.5 exposure during high bushfire smoke days on birthweight and gestational age in Hunter New England, NSW, Australia. A study on pregnant people who smoke and don't smoke.

Australia's 2019/20 bushfire season was one of the most severe on record, from both land mass burned and the economic impact. This extreme weather season allowed the researchers to examine the effect of high PM2.5 exposure during high bushfire days on birthweight and gestational age. It is well known that bushfire smoke is harmful to human health. However, the impact this has on the developing fetus is not yet clear. 25,346 births were assessed, their exposure calculated based on location data, and outcomes analyzed. Mothers exposed to high PM2.5 (measured by a 24-hour average PM2.5 greater than 25µg/m3) demonstrated a significant birthweight reduction of 0.77g per day of exposure. Those who were also self-identified as having smoked at any time during their pregnancy were at higher risk, with a 1.33g reduction in birthweight per day of exposure. Gestational age was reduced by 0.01 days per day of exposure in the total cohort, with no significant difference demonstrated in those who smoked. The compounded effects of high PM2.5 exposure may result in birthweight reduction, with neonates born to mothers who smoked at increased risk.

Characterising the Chemical Composition of Bushfire Smoke and Implications for Firefighter Exposure in Western Australia

This study evaluates bushfire smoke as a workplace hazard for firefighters by characterising its chemical composition and potential health risks in Western Australia. Portable Fourier Transform Infrared (FTIR) spectrometry was used to measure airborne chemical concentrations at prescribed burns across five regions, including peat (acid sulphate) fire events. Samples were collected during both flaming and smouldering phases, as well as in perceived “clear” air resting zones. Results indicated that carbon monoxide (CO) was the dominant gas, reaching concentrations of 205 ppm at the fire front, followed by nitrogen monoxide (26 ppm) and methane (19 ppm). Peat fires produced distinct profiles, with ammonia (21.5 ppm) and sulphur dioxide (9.5 ppm) concentrations higher than those observed in typical bushfires. Smouldering phases emitted higher chemical concentrations than flaming phases 75% of the time. Even clear air zones contained measurable chemicals, with CO levels averaging 18 ppm, suggesting that firefighters are not free from exposure during rest periods. These findings highlight the need for fit-for-purpose respiratory protective equipment (RPE) and improved rest protocols to minimise exposure. The study underscores the importance of comprehensive health monitoring programs for firefighters to mitigate long-term health risks.

Preliminary Assessment of Tunic Off-Gassing after Wildland Firefighting Exposure

Evidence has previously shown that outer tunics (turnout coats) worn by firefighters at structural fires are contaminated with harmful chemicals which subsequently off-gas from the material. However, there is limited research on whether this phenomenon extends to wildland firefighter uniforms. This pilot study aimed to explore if the tunics of volunteer bushfire and forestry firefighters in Western Australia off-gas any contaminants after exposure to prescribed burns or bushfires, and whether there is a need to explore this further. Nine tunics were collected from firefighters following nine bushfire and prescribed burn events, with a set of unused tunics serving as a control. Chemical analysis was performed on these tunics to assess levels of acrolein, benzene, formaldehyde, and sulphur dioxide contamination. The assessment involved measuring chemical off-gassing over a 12 h period using infrared spectrometry. Tunics worn by firefighters appear to adsorb acrolein, benzene, formaldehyde, and sulphur dioxide from bushfire smoke and these contaminants are emitted from firefighting tunics following contamination at elevated concentrations. Further investigation of this research with a larger study sample will be beneficial to understand this phenomenon better and to determine the full extent and range of chemical contaminants absorbed by all firefighter clothing.

A light-blocking greenhouse film differentially impacts climate control energy use and capsicum production

High-tech protected cropping holds great potential to improve global food security, but high cooling energy costs in warm climates pose difficulties in propagating the industry. Emerging technologies, such as diffuse glasses fitted with photoselective thin films, have interactions with crops and other cooling technologies which are not well-characterized for warm-climate glasshouses. A light-blocking film (LBF) was chosen as a high-tech, climate-controlled greenhouse cover permitting transmission of 85% of photosynthetically-active light and blocking heat-generating radiation. Two consecutive 7-month trials of two capsicum crops were grown under warm climate conditions partially impacted by bushfire smoke, with 2 cultivars (Gina and O06614) in the first trial, and 2 cultivars (Gina and Kathia) in the second trial. Capsicum fruit yield decreased by 3% in Gina and increased by 3% in O06614 for the first trial, and decreased by 13% in Gina, 26% in Kathia for the second trial. Cooling energy use increased by 11% and 12% for both capsicum crops in AE and SE respectively, with small but insignificant decreases in fertigation demand (2%–5%). Cooling potential was significantly different from material specifications, with indications that convection from LBF interfaces was responsible for higher heat loads. LBF and similar absorptive glasses may still be beneficial for reducing nutrient, water, and energy use in warm climate glasshouses. However, yield is cultivar-dependent and may decrease with below-optimal crop lighting, whereas energy savings are more dependent on LBF orientation and building geometry than outside climate.

An application of low-cost sensors to monitor children's exposure to air pollution at five schools in Queensland, Australia

There are local variations in the concentration of air pollutants that may not be captured by the existing monitoring networks; however, they can be important because this is where community exposures occur. Using low-cost monitors (LCM) located at relevant community locations, such as schools, can provide information on local sources, exposure and, with the participation of the community, can help to mitigate these problems. As such, this study was conducted to assess the outdoor air quality (PM2.5 and CO) at five schools in Queensland, Australia, over a period of one year using KOALA LCMs. The results allowed us to broadly conclude on the significance of local sources, such as to show that the majority of PM2.5 in the outdoor school environments did not originate from motor vehicle emissions, being more likely from other background sources such as bushfire smoke and surface dust. By comparing the data obtained by two KOALAs, one at the roadside and the other well away from roads, we estimated that only 37% of the PM2.5 near the road originated from motor vehicles. This contrasts with the known observation that, near busy roads, over 80% of particles by number originate from vehicle emissions. This study provides a model for further investigation and helps to improve the understanding of the importance of air quality among schoolchildren and the local communities.

Assessing the potential for bushfire smoke exposure of apples (Malus domestica Borkh) to affect the composition and sensory characteristics of cider

Assessing the potential for bushfire smoke exposure of apples (<i>Malus domestica</i> Borkh) to affect the composition and sensory characteristics of cider

Bushfire-smoke trigger hospital admissions with cerebrovascular diseases: Evidence from 2019-20 bushfire in Australia.

Exposure to ambient air pollution is strongly associated with increased cerebrovascular diseases. The 2019-20 bushfire season in Australia burnt 5.4 million hectares of land in New South Wales alone, with smoke so severe it affected cities in Argentina, 11,000 km away. The smoke emitted by bushfires consists of both gaseous and particle components. It is important to note that exposure to particulate matter has been shown to be linked to a heightened risk of stroke, which is the primary kind of cerebrovascular illness, as well as an increased likelihood of hospitalisations and mortality. However, the available data is inadequate in terms of documenting the response of patients diagnosed with a proven cerebrovascular illness to bushfire smoke. Additionally, there is a lack of information about the health effects associated with particulate matter throughout the bushfire season and on days when smoke was present in 2019 and 2020.Therefore, we aimed to determine the effects of (i) short-term air pollution triggered by bushfires and (ii) high smoke days in increasing the daily number of hospital admissions with cerebrovascular diseases. Hospitalisation data were accessed from the admitted patient dataset from seven local Government areas of Hunter New England Local Health District. The bushfire period was defined from 1 October 2019 to 10 February 2020, and a same period from 2018-19 as the control. High bushfire smoke days were days when the average daily concentration of particulate matter was higher than the 95th percentile of the control period. Poisson regression models and fixed effect meta-analysis were used to analyse the data. In total, 275 patients with cerebrovascular admissions were identified, with 147 (53.5%) during the bushfire (2019-20) and 128 (46.5%) in the control period (2018-19). There was no significant increase in daily admissions for cerebrovascular disease (Incidence Rate Ratio, IRR: 1.04; 95% CI: 0.81-1.34; p-value: 0.73), acute stroke (IRR: 1.15; 95% CI: 0.88-1.50; p-value: 0.29) or acute ischaemic stroke (IRR: 1.18; 95% CI: 0.87-1.59; p-value: 0.28), over the entire bushfire period. However, the high bushfire smoke days were associated with increased acute ischaemic stroke-related hospital admissions across lead 0-3 and the highest cumulative effect was observed with lead 0 (IRR:1.52; 95% CI: 1.01-2.29; p-value: 0.04). In addition, during the bushfire period, particulate matter, both PM10 and PM2.5 (defined as particulates that have an effective aerodynamic diameter of 10, and 2.5 microns, respectively), were also associated with increased acute ischaemic stroke admissions with a lag of 0-3 days. The results suggested a possible association between particulate matter and high smoke days with increased hospital admissions due to acute ischaemic stroke during the recent Australian bushfire season.

Community education on the health impacts of bushfires: Evaluation of an online pilot short course in Tasmania, Australia

Bushfires and smoke pose substantial risks to physical and mental health across exposed populations. Enhanced community-level knowledge and response capability may promote exposure reduction and therefore protect health, however few interventions exist to achieve this goal. We developed an online short course, ‘Bushfires and Your Health’, and piloted it with older adults as a vulnerable group. We evaluated course satisfaction, factors associated with course enrolment and completion, the likelihood of increased bushfire knowledge and response capability, and the likelihood of participants undertaking risk-mitigating or health-promoting actions. We (i) used a pre-post-course survey in the intervention group and a control group (who did not undertake the course); (ii) gathered data from the intervention group via a post-course feedback survey; and (iii) analysed participant discussion board submissions for evidence of course-related behaviour change. Compared to the control group, course enrolment was significantly positively associated with several demographic characteristics, including being retired (OR = 1.32, 95 % CI[1.02–1.71]), living in proximity to bushland (OR = 1.58, 95 % CI[1.23–2.04]) and having an existing bushfire survival plan (OR = 1.34, 95 % CI[1.05–1.70]), and significantly inversely associated with being employed (OR = 0.76, 95 % CI[0.59–0.97]) and having poor bushfire knowledge (OR = 0.78, 95 % CI[0.61–0.99]). Compared to the control group, course completion was significantly associated with increased bushfire knowledge, while enrolment and completion were significantly associated with participants undertaking new actions, including downloading and using an air quality app, developing a bushfire survival plan and making household preparations. An online short course has potential to increase knowledge and preparedness actions when managing bushfires and bushfire smoke.

Pregnant women’s experiences of extreme exposure to bushfire associated smoke: a qualitative study

In 2019/2020, multiple bushfires burned across south-east Australia converging into unprecedented megafires that burned 5.8 million hectares. From October 2019–February 2020, 80% of Australians were affected by smoke from these fires, exposing them to dramatic increases of PM2.5 in the air at an average level of ∼70 μg m3 per day, well above the World Health Organisation recommendation of ∼10 μg m3. Maternal exposure to PM2.5 has been associated with negative birth outcomes and an increased rate of birth defects, yet there is a dearth of literature regarding how pregnant women deal with exposure to bushfire smoke. The aim of this study was thus to investigate how pregnant and postpartum women experienced severe bushfire smoke associated with the 2019–2020 bushfires in south-east Australia and the strategies they used to mitigate exposure to smoke for themselves and their unborn or newborn children. Forty-three women who were exposed to fire and/or smoke from the 2019–2020 bushfires participated in one-on-one semi-structured interviews via phone or videoconference. These women were selected purposively from a larger group of women who had elected to be interviewed. After interview, data were transcribed and thematically analysed using the four phases of disaster response (prevention, preparedness, response, recovery) as a frame. Overall, our results indicated that public health advice failed to meet the unique needs of this group. While many protected their properties appropriately and were reasonably well prepared for evacuation, they were unprepared for the disruption to vital services including power and communications. Women exposed to smoke inundation were unprepared for this outcome and self-initiated a variety of strategies. The support of community was also key to recovery. There is a clear need for specific recognition of the needs of pregnant women across all phases of disaster response, incorporating public health messaging, peer support, and access to resources.

Camera-based automated monitoring of flying insects in the wild (Camfi). II. flight behaviour and long-term population monitoring of migratory Bogong moths in Alpine Australia.

The Bogong moth Agrotis infusa is well known for its remarkable annual round-trip migration from its breeding grounds across eastern and southern Australia to its aestivation sites in the Australian Alps, to which it provides an important annual influx of nutrients. Over recent years, we have benefited from a growing understanding of the navigational abilities of the Bogong moth. Meanwhile, the population of Bogong moths has been shrinking. Recently, the ecologically and culturally important Bogong moth was listed as endangered by the IUCN Red List, and the establishment of a program for long-term monitoring of its population has been identified as critical for its conservation. Here, we present the results of two years of monitoring of the Bogong moth population in the Australian Alps using recently developed methods for automated wildlife-camera monitoring of flying insects, named Camfi. While in the Alps, some moths emerge from the caves in the evening to undertake seemingly random flights, filling the air with densities in the dozens per cubic metre. The purpose of these flights is unknown, but they may serve an important role in Bogong moth navigation. We found that these evening flights occur throughout summer and are modulated by daily weather factors. We present a simple heuristic model of the arrival to and departure from aestivation sites by Bogong moths, and confirm results obtained from fox-scat surveys which found that aestivating Bogong moths occupy higher elevations as the summer progresses. Moreover, by placing cameras along two elevational transects below the summit of Mt. Kosciuszko, we found that evening flights were not random, but were systematically oriented in directions relative to the azimuth of the summit of the mountain. Finally, we present the first recorded observations of the impact of bushfire smoke on aestivating Bogong moths - a dramatic reduction in the size of a cluster of aestivating Bogong moths during the fire, and evidence of a large departure from the fire-affected area the day after the fire. Our results highlight the challenges of monitoring Bogong moths in the wild and support the continued use of automated camera-based methods for that purpose.

Healthcare complexities during community crises: Recommendation for access to healthcare for Australians with multiple sclerosis.

In 2019 and 2020, over 17 million hectares of Australia burned, and half of the Australian population was affected by toxic bushfire smoke. Then in 2020, restrictions designed to curtail the spread of COVID-19 resulted in significant changes to healthcare access. There is no Australian emergency management standard for persons with disabilities, including those with multiple sclerosis (MS). Persons with MS often require multidisciplinary and complex care, with continuity of treatment essential to prevent disease progression. To identify limitations in access to healthcare from the perspective of persons with MS as well as MS care providers during recent crises and make recommendations for policy to improve MS healthcare access during a crisis. In mid-2020, we undertook online surveys and interviews with persons with MS, their carers, healthcare professionals and staff of MS service providers (i.e., care providers). We used descriptive analysis for quantitative, and a general inductive approach for qualitative data. One-hundred and thirteen persons with MS and a total of 63 MS care providers, who were close carers, healthcare professionals and service providers provided survey responses. For participants with MS, limited access to general practitioners and medical tests were of the most significant concern during the bushfires and the pandemic. In contrast, during the pandemic accessing physiotherapy was another top concern. Twenty-nine people participated in in-depth interviews, revealing that reduced healthcare access during the bushfire and the pandemic caused concern. The use of telehealth received both positive and negative reviews. All participants indicated a need for preparation and planning for healthcare access before a crisis. Persons with MS recommended centralised information sources, prioritised access to healthcare and increased levels of MS nurses and other allied healthcare. Care providers recommended centralised information sources, more nursing and mental health care access, and increased opportunities for multidisciplinary telehealth delivery. We recommend the involvement of the MS community in creating and designing disaster preparation plans, which should cater to a range of disaster types, to improve disaster preparedness in a community that is vulnerable to increasingly common community crises.

Exercise in bushfire smoke for high performance athletes: A Position Statement from the Australian Institute of SportEndorsed by Australasian College of Sport and Exercise Physicians (ACSEP) and Sport Medicine Australia (SMA).

The frequency of bushfires in Australia is increasing and it is expected bushfire smoke will become a more prevalent phenomenon impacting air quality. The objective of this position statement is to provide guidance to the sport sector regarding exercise in air affected by bushfire smoke. This is position statement from the Australian Institute of Sport, based on a narrative review of the literature regarding bushfire smoke and its effects on health and exercise performance. A narrative review of scientific publications regarding the effects of bushfire smoke on health and exercise performance. Bushfire smoke has negative impacts on health and performance. Athletes exercising at high intensity over a prolonged duration will increase their exposure to air pollutants. Athletes with a history of elevated airway responsiveness are likely to be at increased risk of an adverse response to bushfire smoke exposure. Athletes, coaches, support staff and sport organisations should monitor air quality (PM2.5 concentration) and make appropriate adjustments to training duration and intensity.

Cardiac Autonomic Impacts of Bushfire Smoke - A Prospective Panel Study.

Air pollution is associated with cardiovascular disease and mortality. Most studies have focussed on urban or traffic-related pollution, and less is known about the impacts from bushfire smoke on cardiovascular autonomic function, although it is associated with increased sudden cardiac death and mortality. We sought to investigate its instantaneous and short-term impacts on heart rate variability (HRV). Twenty-four (24)-hour Holter electrocardiography (ECG) was repeated twice (during bushfire [Phase 1] and then clean air [Phase 2]) in 32 participants from two Australian towns (Warburton and Traralgon, Victoria) surrounding planned burning areas. This was compared with 10 control participants in another town (Maffra, Victoria) with two clean air assessments during the same periods. The primary HRV parameters assessed were those assessing overall HRV (Standard Deviation of Normal-to-Normal intervals [SDNN]), long-term HRV (Standard Deviation of the Average of Normal Sinus-to-Normal Sinus intervals for each 5-minutes [SDANN]), low frequency [LF]) and short-term HRV (Root Mean Square of Successive Differences between N-N intervals [RMSSD], High Frequency [HF], LF:HF ratio). Average concentrations of particulate matter <2.5 μm in diameter (PM2.5) were measured at fixed site monitors in each location. Mean PM2.5 levels were significantly elevated during bushfire exposure in Warburton (96.5±57.7 μg/m3 vs 4.0±1.9 μg/m3, p<0.001) and Traralgon (12.6±4.9 μg/m3 vs 3.4±3.1 μg/m3, p<0.001), while it remained low in the control town, Maffra, in each phase (4.3±3.2 μg/m3 and 3.9±3.6 μg/m3, p=0.70). Although SDANN remained stable in controls, the exposed cohort showed significant worsening in SDANN during bushfire smoke exposure by 9.6±25.7ms (p=0.039). In univariable analysis, smoke exposure was significantly associated with higher ΔSDNN and ΔSDANN (p=0.03, p=0.01 exposed vs control). The association remained significant in ΔSDANN after adjusting for age, sex and cigarette smoking (p=0.02) and of borderline significance in ΔSDNN (p=0.06). Exposure to the bushfire smoke was independently associated with reduced overall and long-term HRV. Our findings suggest that imbalance in cardiac autonomic function is a key mechanism of adverse cardiovascular effects of bushfire smoke.

A case of spillover rain coinciding with bushfire smoke

A case of spillover rain coinciding with bushfire smoke

Acute health effects of bushfire smoke on mortality in Sydney, Australia

BackgroundBushfire smoke is a major ongoing environmental hazard in Australia. In the summer of 2019–2020 smoke from an extreme bushfire event exposed large populations to high concentrations of particulate matter (PM) pollution. In this study we aimed to estimate the effect of bushfire-related PM of less than 2.5 μm in diameter (PM2.5) on the risk of mortality in Sydney, Australia from 2010 to 2020. MethodsWe estimated concentrations of PM2.5 for three subregions of Sydney from measurements at monitoring stations using inverse-distance weighting and cross-referenced extreme days (95th percentile or above) with satellite imagery to determine if bushfire smoke was present. We then used a seasonal and trend decomposition method to estimate the Non-bushfire PM2.5 concentrations on those days. Daily PM2.5 concentrations above the Non-bushfire concentrations on bushfire smoke days were deemed to be Bushfire PM2.5. We used distributed-lag non-linear models to estimate the effect of Bushfire and Non-bushfire PM2.5 on daily counts of mortality with sub-analyses by age. These models controlled for seasonal trends in mortality as well as daily temperature, day of week and public holidays. ResultsWithin the three subregions, between 110 and 134 days were identified as extreme bushfire smoke days within the subregions of Sydney. Bushfire-related PM2.5 ranged from 6.3 to 115.4 µg/m3. A 0 to 10 µg/m3 increase in Bushfire PM2.5 was associated with a 3.2% (95% CI 0.3, 6.2%) increase in risk of all-cause death, cumulatively, in the 3 days following exposure. These effects were present in those aged 65 years and over, while no effect was observed in people under 65 years. ConclusionBushfire PM2.5 exposure is associated with an increased risk of mortality, particularly in those over 65 years of age. This increase in risk was clearest at Bushfire PM2.5 concentrations up to 30 µg/m3 above background (Non-bushfire), with possible plateauing at higher concentrations of Bushfire PM2.5.

The use of simultaneous IBA techniques to fingerprint fine particle emissions during the Australian bushfire 2019-20 black summer event.

The outputs of the multi-elemental IBA techniques of PIXE, PIGE, RBS and PESA have been used as inputs to positive matrix factorisation source apportionment methods to quantify and fingerprint bushfire smoke during the catastrophic black summer bushfires of 2019-20 season in NSW, Australia.

Bushfire Smoke and Children's Health-Exploring a Communication Gap.

The “Black Summer” bushfires of 2019/2020 in Australia generated smoke that persisted for over three months, mainly affecting Eastern Australia. Most communication strategies focused on the fire itself, revealing a knowledge gap in effective communication of the impact of bushfire smoke on health, especially for children and those living in non-English speaking minority groups. To address this, semi-structured qualitative interviews were undertaken with sixteen adults with caring (n = 11) or educational (n = 5) responsibilities for primary-school aged children (5–12 years, with some also having children up to 16 years) who had direct experience of the “Black Summer” bushfires. Overall, 43% (n = 7) of the sample spoke English as a first language, 25% (n = 4) spoke Turkish, with the remainder speaking Persian, Arabic, and Spanish. Thematic inductive qualitative content analysis revealed predominant themes of the role of parents and caregivers as conduits and curators of information. Air quality apps were the most common source of information. Language barriers and the lack of child-friendly methods of communication were highlighted as particular challenges. This qualitative study provides evidence for future development of communication strategies to better serve culturally and linguistically diverse individuals and the children in their care.

Building community and health system resilience to climate disasters in Australia

Australia has recently experienced severe climate disasters, ranging from bushfires and droughts to floods and vector borne disease outbreaks. IPCC identified the inability of institutions to manage climate risks as a key risk for Australia. The unprecedented 2019-20 wildfires and the 2022 floods have raised questions about the resilience of the Australian health system and communities to intensifying extreme events in the context of climate change. The 2022 floods caused 23 deaths, large-scale community devastation, and disrupted health services. They increased COVID-19 and other infectious disease risks and long-lasting mental health consequences. Furthermore, they exposed health inequities and vulnerabilities related to non-communicable diseases in Aboriginal and low socio-economic communities. The Black Summer (2019-20) wildfires caused 33 fatalities, extensive damage to property, and destruction of flora and fauna, as well as exposing millions of people to extreme levels of air pollution. Bushfire smoke, a complex mixture of particles and gases, was transported by the wind over long distances affecting populated areas for several weeks. Public health interventions at both community, household and personal levels can mitigate the impact of climate disasters. The effectiveness, feasibility and scalability of these interventions, as well as any potential health co-benefits or other unintended consequences, need to be evaluated holistically taking into account quantitative and qualitative evidence. The impact of these interventions on health equity, particularly in relation to First Nations, at-risk and socioeconomically marginalized groups needs to be assessed, as these groups are typically more vulnerable to climate extremes. Strengthening the long-term resilience of the health sector and communities to climate disasters is crucial. The HEAL (Healthy Environments And Lives) Network is taking leadership in environmental change and health research that will provide the evidence, capacity and capability, and tools urgently needed to build community and health system resilience to intensifying climate disasters in Australia.

Bushfire smoke plume composition and toxicological assessment from the 2019–2020 Australian Black Summer

Many of the population centres in southeast Australia were swathed in bushfire smoke during the 2019–2020 austral summer. Bushfires burning during what is now known as the Black Summer was historically large and severe, and the fire season historically long. The chemical composition in the gas and aerosol phase of aged plumes measured near Wollongong, NSW in early 2020 is reported in this work. Enhancement ratios to carbon monoxide are presented for thirteen species (acetaldehyde, acetone, acetonitrile, black carbon aerosol, benzene, methane, methacrolein + methyl vinyl ketone, methyl ethyl ketone, methanol, ammonium ion PM1 fraction, nitrate ion PM1 fraction, organic PM1 fraction and PM2.5). Observed plume composition is comparable to that measured in fresh smoke from Australian fires reported in the literature. Enhancements of biogenic volatile organic compounds such as isoprene (smoke-effected period mean 1 ppb, maximum 6 ppb) were observed along with elevated concentrations of particulate variables. Enhancement ratios reported here can be used in plume modelling of landscape-scale fires and assist in concentration estimates of infrequently measured atmospheric pollutants. The relative toxicological contribution of species present in the plumes was determined for plume exposure at the measurement site and for concentrated plumes at a population centre case study. Similar results were apparent at both locations. Contributions to the toxicological loading were dominated by respirable particles (~ 52–63% total contribution), formaldehyde (~ 30–39% total contribution) and acrolein. This is a reminder to consider the toxicological contributions in the gas phase when considering health impacts of population exposure to bushfire smoke.

Respiratory presentations and admissions at Bathurst Base Hospital emergency department: Exploring the impacts of the recent bushfire crisis.

To examine respiratory-related ED admissions and presentations at Bathurst Base Hospital during the 2019-2020 New South Wales bushfire crisis. A retrospective clinical audit was undertaken. Publicly available data on air quality were also examined. Poorer air quality (measured by PM10 levels) was correlated with increased presentations to the ED (R= 0.228, P= 0.012). ED patients with respiratory diagnoses were more likely to be admitted for inpatient care in 2019-2020 (n= 234, 49.3%) compared with 2018-2019 (n= 165, 39.6%). The impact of bushfire smoke needs to be considered in the allocation of resources in this area in future, but further research is warranted to understand the full extent of impact at the local level.