Air Quality

Model estimating the attributable number of deaths due to all sources (PM2.5 and NO2) and specifically due to traffic-related air pollution (TRAP) in Australia, based on 2015 data.

The model shows that emissions from vehicles—primarily fine particulate matter (PM_2.5) and nitrogen dioxide (NO₂)—contribute to over 1,800 premature deaths annually.

Check the map on the Centre for Safe Air website for PM2.5 and NO2 from all sources or from traffic-only, and associated premature deaths and years of life lost, by state, Greater capital city area or Statistical Area Level 4: Traffic health map – Centre for Safe Air

Study using previously published predictions for all sources PM2.5 and NO2 and models to estimate traffic-related air pollution (TRAP) in 2015.

Results:

• an estimated 3684 (95 % CI, 3051–4350) premature deaths were attributable to air pollution from all sources
• 51 % (95 % CI, 19 %–86 %) of these (more than 1,800 premature deaths) were linked to TRAP.

These estimates are lower than previous estimates of 11,000 annual deaths from TRAP by the University of Melbourne (2023) although this study was not peer-reviewed and published.

Conclusion: Air pollution remains a significant contributor to mortality in Australia. Reducing exposure, particularly from TRAP, could yield substantial public health benefits. Policies promoting cleaner transport modes offer a promising avenue for rapid improvement.

A systematic review and meta-analysis looking at the link between air pollutants and incidence of asthma in adults.

Findings:

• 7% increased risk of developing adult asthma per 5 ug/m3 increase in particulate matter (PM2.5) exposure (pooled risk ratio 1.07 [95% CI 1.01 to 1.13], based on 9 studies)
• 11% increase in risk of developing asthma per 10 ug/m3 increase in nitrogen dioxide (NO2) (pooled risk ratio 1.11 [1.03 to 1.20], based on 9 studies)
• No significant association between ozone (O3) and developing asthma (pooled risk ratio 1.04 [0.79 to 1.36]), based on 4 studies)

Note: due to high variations between studies (heterogeneity), results should be interpreted with caution and further research is needed.

TSANZ has published a position statement advocating for the use of DPI or soft-mist inhalers, as ‘green inhalers’. It is a good resource for deep understanding of the carbon footprint of inhalers, current practices/context and their impact. Some facts include:
– Over 8 millions of pMDIs were dispensed in Australia in 2022
– Percentage of inhaler doses delivered by pMDI exceeds 80% in Australia, United States and United Kingdom
– One person changing from MDI to DPI preventer is similar to changing from a petrol to a hybrid car, or going from meat-eater to vegetarian, over a full year.
– Research and development is also underway to commercialise MDIs with low-emission propellants, with carbon footprint almost 10 times smaller
– Two thirds of inhaler related greenhouse gas emissions are related to high reliever use, which could be decreased by better preventer adherence and asthma control.

The statement includes strategies to mitigate the impact, including Prescribing strategies (including the use of AIR therapy) and Recycling and reuse.

A Victorian retrospective pharmacy-based database search of all inpatient inhaler dispensing from 1 July 2022 to 30 June 2023 at The Royal Melbourne Hospital.
Findings:
– 9,246 inhalers were dispensed in a year, of which 79% were MDIs and accounted for 99% of the total inhaler carbon footprint
– Salbutamol MDI (51%), ipratropium MDI (12.5%) and budesonide/formoterol MDIs (8%) were the most frequently dispensed inhalers, accounting for 71.5% of total inhalers dispensed
– Tiotropium respimat (406 inhalers) and budesonide-formoterol DPI (379 inhalers) were the most frequently dispensed SMI/DPIs but accounted for only 4.39% and 4.01% of dispensed inhalers respectively
– the Carbon footprint of MDIs used for asthma and COPD at the hospital was equivalent to providing electricity to 50 homes for a year.
Conclusion: the environmental impact of inhaler choice should be considered in decision-making around prescribing

A study in 668 adults asthma patients looked at the carbon footprint of inhalers and found that as needed budesonide-formoterol DPI (e.g. Symbicort) resulted in:
– 95.8% less carbon emission than as-needed salbutamol pMDI (e.g. Ventolin)
– 93.6% less carbon emission than maintenance budesonide DPI + as-needed salbutamol pMDI

Note: this is a rather small study.

A study including 236K participants with poorly controlled asthma in the UK reported that poorly controlled asthma results in:
– 3 times the carbon emissions of well-controlled asthma (on average)
– Excess was largely driven (90%) by inappropriate use of SABA.

Researchers analysed the carbon footprint of inhaled medications in Europe using 2020 European sales data, and estimated the emissions of different treatment regimens on Global Initiative for Asthma (GINA) step 2.
Findings:
– There is potential to reduce the carbon footprint of inhaled medications by 85% if DPIs are preferred over pMDIs.
– For moderate asthma, as-needed ICS/LABA had a substantially lower annual carbon footprint (0.8 kg CO2e) than the more traditional maintenance ICS + as-needed SABA (2.9 kg CO2e)
– Emissions from pMDIs in the EU were estimated to be 4.0 megatons of carbon dioxide equivalent (MT CO2e) which could be reduced to 0.6 MT CO2e if DPIs were used instead

A population-based study in WA analysing hospital admissions in Perth in 2015-2017 and smoke exposure using a model tracking PM2.5 levels during 1700 bushfires and burn offs found that following exposure to high PM2.5 (12.60 mcg/m3 or higher) there was:
– 16% (RR 1.16, 95% CI 1.00 to 1.35) increase in hospital admissions on the same day as exposure
– 93% increase in asthma hospitalisations the next day (lag of 1 day) for children
– 52% increase in asthma hospitalisations on a lag of 3 days in low socio-economic groups.

Healthcare sector emissions in Australia 2023,
– Australia is ranked eleventh highest in the world in terms of the nation’s health care sector position with respect to its per capita greenhouse gas emissions
– In 2020, Australia’s total emissions were 28.9 Mt, which includes emissions from a range of greenhouse gases that are emitted directly by the health sector, and emissions resulting from the demand of goods and services for running health care operations.
– there has been a 30% increase in total emissions in 2020 and a 28% increase in per capita emissions from 878.3 kg per capita in 2019 to 1125.2 kg per capita in 2020, compared to 2019.

PM2.5 air pollution in Australian cities between 2000 and 2023, MJA-Lancet Countdown report 2023
– The average city exposure in Australia has generally declined over time but has major fluctuations as a result of bushfires and dust storms
– Some states experience significant seasonal variations — due to the dry season in the Northern Territory and the use of wood heaters in the cooler southern regions
– The annual average PM2.5 concentrations in Australian cities were lower than in cities from many other countries (which can be as high as 35 μg/m3 annual average) but are still above the latest WHO annual air quality guideline of 5 μg/m3 but mostly below the Australian advisory reporting standard of 8 μg/m3

Increasing exposure to bushfires in Australia
After the 2019–20 Black Summer bushfires, Australians have been exposed to lower bushfire danger conditions. Nevertheless, the overall trend shows an increase over time in the exposure to very high or extremely high bushfire danger, with average annual exposure in the past ten years (2013–2022) considerably increasing to 33.6 days per person from 27.5 days per person in the previous ten years (2003–2012).

Research estimates that wood heater smoke in Australia is linked to 558-1555 earlier than expected deaths each year, and halving the number of wood heaters in Australia would create health benefits of between $AUD 1.61 billion to $AUD 1.93 billion per year.

Note: The data visualisation tool in this study shows estimated wood heater pollution-related health impacts across Australia. Using this tool you can explore the estimates by State/Territory, by Greater Capital City Statistical Area, or by Statistical Area Level 4. The tool also enables you to select what estimates to display: wood heater emissions (WHE) (kg/year), population-weighted WHE-fine particulate matter (PM2.5) concentrations, the number of earlier than expected deaths, or deaths per 100,000 people.

The Visualisation tool can be accessed at https://safeair.org.au/data-visualisation-wood-heater-pollution-mortality-in-australia/

Wood heater emissions (2015)

Earlier than expected deaths due to wood heater emissions (2015)

Earlier than expected deaths per 100,000 people due to wood heater emissions (2015)

Editorial article in the Lancet providing statements/ references for:
– 70% of total annual deaths in the world are estimated to be due to climate sensitive diseases
– climate is the biggest health threat facing humanity
– Australia is on the frontline of of the climate change catastrophe
• Australia and its citizens lead all other regions of the world in per capita greenhouse gas emissions from our energy sector, with, on average, each of us contributing significantly to the changing climate and the death and disease it is causing.
• Australia’s health care sector has the eleventh highest per capita greenhouse gas emissions in the world.

This report rated air quality for 36 sites around Australia. The results ranged from half-a-star to four-and-a-half stars, with an average of two-and-a-half stars. One of the common reasons for reduced ratings was the influence of landscape fires, especially the Black Summer bushfires of 2019-2020, and annual savannah burning in the Top End of the Northern Territory. These caused multiple elevated pollution days and drove long-term trends. Another contributor in many locations was seasonal pollution from wood heater emissions.

This report highlights a wide variation in air quality around the country, and provides air quality rating by states for various sites (urban and regional), and the plausible reasons for the trends in air quality (bushfires, wood heaters etc). There is considerable potential for interventions to protect health and improve air quality.

This provides:
– review of the impact of Landscape Fire Smoke (LFS) exposure
– greater impact on vulnerable groups, particularly older people, pregnant woman and Aboriginal and Torres Strait Islander peoples
– development of asthma on the background of risk factors
– advice for asthma management, smoke mitigation strategies and access to air quality information, that should be implemented during periods of LFS

This report explains why the effects of air pollution are so far reaching and, equally, why coordinated action to make air safer is one of the best investments in Australian health.
The report by the Centre for Safe Air includes evidence and information about the health effect of poor air quality, including on asthma.

Asthma Australia internal report on Air pollutants, including what they are, their health impact and Australian standards
(Note that this report was finalised in January 2022, national standards may need to be updated)

accessible here: https://asthmafoundation.sharepoint.com/:w:/s/RPA/ER_83-TCXSNNo-Uea4SJOfcBui-dibb4J63DN2GJh5nJ5g?e=weJ6ay

–This is an internal report, for internal use only–

Longitudinal study examined the experiences and health impacts of prolonged wildfire (bushfire) smoke exposure in adults with severe asthma during the 2019-2020 Australian bushfire period.

The bushfires that swept across Australia in 2019–2020 resulted in 33 deaths, destruction of over 3,000 houses and millions of hectares. Bushfire smoke exposure was significantly associated with an increased risk of respiratory morbidity. Nationally, hospitalisation rates increased for asthma and COPD coinciding with increased bushfire activity during the 2019–20 bushfire season. For asthma, the highest increase was 36% in the week beginning 12 January 2020 (2.4 per 100,000 persons) compared to the previous 5-year average (1.7 per 100,000 persons).
For Emergency Department presentations, asthma saw the highest increase of 44% in the week beginning 12 January 2020 (4.7 per 100,000 persons compared to the previous bushfire season (3.3 per 100,000 persons).

A study of asthma exacerbation emergency department visits in Brisbane suggests that the risk of childhood asthma exacerbations increases within a few hours of air pollution exposure in children aged 0-14, with the risk increasing within the same hour of exposure to O3, and 4 hours after exposure to NO2.
In the study, there was also an association between exposure to PM2.5 and PM10 in some age groups, with children aged 0-4 being more vulnerable to PM10 but less vulnerable to NO2 compared to school-aged children (5-14 years).

A group of international scientists have published in Science proposed standards and recommendations for Indoor Air Quality for public buildings.

Article in the Australian Journal of General Practice summarising the increased risk of asthma associated with gas cooking, how to recognise the clinical implications in children and adults with asthma, and how to advocate for them.
Some reported facts: (please refer to article for exact references)
– 65% of houses in Australia use gas for cooking or heating
– The most important gas-related health effects are due to nitrogen dioxide (NO2) and carbon monoxide (CO)
– an estimated 30% of the risk of asthma for a child with current asthma living in a home with a gas stove comes from the stove
– across the community in Australia, 12% of childhood asthma is attributable to the use of gas stoves
– the risk of persistent asthma was also increased in Tasmanian aged 43-53 years living with gas heating and cooking, with OR 2.64 (1.22–5.70)
– questions about indoor gas exposure should be part of asthma review, and strategies discussed to reduce exposure

– PM2.5: 5 μg/m3 Annual average; 15 μg/m3 24-hour average
– PM10: 15 μg/m3 Annual average; 45 μg/m3 24-hour average
– O3: 60 μg/m3 Peak season average; 100 μg/m3 8-hour average
– NO2: 10 μg/m3 Annual average; 25 μg/m3 24-hour average
– SO2: 40 μg/m3 24-hour average
– CO: 4 mg/m3 24-hour average

An Australian study to estimate the annual burden of mortality and the associated health costs attributable to air pollution from wood heaters in Armidale, a regional Australian city (population, 24 504) with high levels of air pollution in winter caused by domestic wood heaters, 1 May 2018 – 30 April 2019. The health impact (excess annual mortality and financial costs) was assessed based upon atmospheric PM2.5 measurements.
Results:
– 14 premature deaths/year (95% CI, 12–17 deaths), corresponding to 210 years of life lost (95% CI, 172–249) are attributable to long term exposure to wood heater PM2.5 pollution in Armidale.
– The estimated financial cost is $32.8 million (95% CI, $27.0–38.5 million), or $10 930 (95% CI, $9004–12 822) per wood heater per year.
Conclusions: The substantial mortality and financial cost attributable to wood heating in Armidale indicates that effective policies are needed to reduce wood heater pollution, including public education about the effects of wood smoke on health, subsidies that encourage residents to switch to less polluting home heating (perhaps as part of an economic recovery package), assistance for those affected by wood smoke from other people, and regulations that reduce wood heater use (eg, by not permitting new wood heaters and requiring existing units to be removed when houses are sold).

Research article in MJA, single study
Australian study by Dorothy Robinson. A Podcast is also available with the article where she discusses the study findings.

Introduction
– Impacts of climate change on allergens and allergic diseases are multifaced and supported by a body of sophisticated research (mostly international)
– Prevalence of asthma and allergy is high in Australia by international standards
– Research in Australia links environmental allergen exposure and outdoor fungal spores to health outcomes such as sales of anti-allergic medications, asthma emergency department presentations and asthma hospitalisation
– Climate plays a large role in allergic organisms, impacting production and our eventual exposure
– Australians vulnerability to adverse impacts of climate change on allergens and allergic diseases was highlighted by the 2016 epidemic thunderstorm asthma event in Melbourne.

Methods: A review of international and Australian research on climate change, allergens and allergy published from 2000 onwards.

Results and Discussion
Impacts of climate change on allergens and allergic disease are many and varied, including;
– Increase in pollen production, atmospheric concentration and allergenicity, changes in seasonality, and dispersion;
– Changes in fungal spore seasonality and increase in production and allergenicity;
– Changes to indoor environment such as moisture and mold growth;
– Changes in distribution and seasonality of stinging insect allergens;
– Increase in allergenicity of plans which cause skin reactions; and
– Potential increase in concentration of food allergens, such as peanuts (understudied area).
Research primarily focuses on impacts of increasing or projected increase in temperatures and CO2.
Pollen is the key focus of the article/where the bulk of the evidence is
Most studies are international, and while some included allergens present in Australia, there is an urgent need for Australian focused research.
Given the high prevalence of allergic diseases in Australia, it could be argued that these impacts pose a serious climate change-human health risk to Australia and should be a priority.
In Australia, no national or state/territory body has responsibility for the monitoring, reporting and forecasting of environmental allergens such as airborne pollen and fungal spores. Our monitoring is still geographically sparse and sporadic (e.g. some monitor for 3-month period and some year-round). This is due to poor, limited or short-term funding.
Australia has an impressive wealth of experience and expertise which we should be drawing on.

Nicolas Borchers is supported through a PhD scholarship from AA.

Research based in Tasmania, given the high rate of wood fire heater use during winter which produced fine particulate matter, harmful to human health and particularly people with asthma or other chronic conditions. The researched aimed to estimate the historical health impacts and health costs from PM2.5 produced by wood heater smoke and landscape fire smoke (includes wildfires and hazard reduction burning)
Method
– Modelling study
– health impact assessment to estimate the number of cases and costs due to premature mortality, cardiorespiratory hospital admissions, asthma ED visits
– analysed historical air pollution, temperature and assessed where PM2.5 was due to landscape fire or wood fire heaters
– between January 2010 and December 2019
– characterise days an unpolluted or polluted, and if polluted determine whether they were primarily woodfire heater and landscape fire smoke
Results
– estimated 69 deaths, 86 hospital admissions and 15 asthma ED visits each year, with 74% of impacts attributable to wood fire heaters
– estimated yearly average health costs were $293 million for wood fire heaters, and $16 million for landscape fire smoke
– during extreme bushfire seasons, landscape fire smoke cost more than $34 million per year
– unlike wood fire heaters, landscape fire impacts are not distributed evenly from year to year, but vary according to the intensity of the bushfire season. If you exclude 2016 and 2019 from the analysis, the yearly cases drops substantially for landscape fire smoke

– Applied a consistent framework to model impacts of PM2.5 from eight major sources in Greater Metropolitan Region of Sydney for the year July 2010-June 2011
– Estimated the burden of current mortality attributable to this sources and number of life-years that would be produced if emissions from largest sources were reduced
– Wood heaters were the most important source of PM2.5 exposure, responsible for around 24% of the PM2.5 concentration. Followed by on-road sources (16.9%) and power stations (10.5%).
– Assumes a real-world emissions factor of 11.4 g of PM2.5 per kg of wood burned
– 50% ambient PM2.5 was from wood heaters, on-road sources and power stations.
– Wood heaters were the most important source, responsible for 1,400 YLL annually.
– Around 1.2% of mortality (5,900 YLL) was attributable to long-term exposure to all anthropogenic PM2.5, including 0.3% (1,400 YLL) attributable to wood heater–related PM2.5, 0.2% (990 YLL) to on-road sources and 0.1% (620 YLL) to power stations.
– Introduction of a 1.5 g/kg standard for wood heaters could produce 90,000 life-years.
– Estimated that if there was a sustained reduction in emissions from wood heaters due to the introductions of emissions standards of 1.5g of PM2.5 per kilogram of wood burned, this would produce 90,000 life years among the people alive in 2010/11.
– Although the burden of mortality attributable to each source is relatively small, interventions that achieve sustained reductions in emissions could provide substantial health benefits, which are likely to far outweigh the costs.

The purpose of this study was to conduct a systematic review and meta-analysis of the associations between short-term exposure to landscape fire smoke PM2.5 and asthma related outcomes including; hospital admissions, emergency department visits, physician visits, medication use and salbutamol dispensations. To the best of the researchers knowledge, this is the first meta-analysis to obtain summary estimates between fire smoke PM2.5 and asthma related outcomes.
From 181 initial articles, 20 were included for quantitative assessment and descriptive synthesis. Eight studies were from Australia and the USA, four studies were from Canada.
Findings
• Fire smoke PM2.5 levels are positively associated with asthma hospitalisation and ED visits for all ages and sexes
• Females and people over the age of 65 were most susceptible to the landscape fire smoke
• Short term impacts of landscape fire smoke are worse than those from multi-source urban pollution
Short-term exposure to fire smoke PM2.5 is positively associated with asthma-related outcomes, and this is association is higher than from typical multisource pollution. During short fire periods, people are exposed to higher concentrations of particulate matter.
Fire smoke PM2.5 levels were positively associated with asthma hospitalisations and ED visits for all age groups and sexes. Hospital admissions results show that smoke effects could last for multiple days, while for ED visits effects tended to occur on the same day as exposure.
There was a stronger association between fire smoke PM.25 and ED visits/hospitalisations with increasing age. Adults were more susceptible than children, and elderly more susceptible than adults. This is different to evidence related to multisource air pollution where children were most sensitive. Females were more susceptible to fire smoke than males
There is likely an association between fire smoke PM2.5 and physician visits, salbutamol dispensations and medication use in adults but the evidence available is too limited for statistically significant results.

In May 2016 there were hazard reductions burns conducted around Sydney causing smoky conditions and high PM2.5 concentrations for several days. This study assessed the impact of smoke-related PM2.5 on all-cause mortality and hospitalisations for cardiovascular and respiratory conditions in Sydney. Six days were identified as being clearly smoky. It was estimated that 14 premature deaths and 58 respiratory hospitalisations were attributable to these smoky days. This highlights the potential scale of the public health impacts when smoke affects a population of nearly 5 million people for several days.

An assessment of all-cause mortality and hospitalisations for cardiovascular and respiratory disease in Sydney between 2001 and 2013 quantified the population level health effects attributable to exposure to landscape fire events in Sydney. Verified dates for landscape fire events were located and background PM2.5 and health burden were estimated. Health Burden was estimated from death and hospitalisation incidence rates, daily PM2.5 exposure and risk estimates recommended by WHO. The results found that the health impacts of landscape fire smoke exposure during 2001-2013, was similar to a May 2016 incident every 12 months (14 premature deaths and 58 respiratory hospitalisations). Health risk estimates are likely conservative as they assumed short term, immediate impacts of increased PM2.5 but extended exposure is likely to have greater effects

According to the Burden of Disease report, at least 3,000 deaths (equivalent to about 28,000 years of life lost) per year in Australia are attributable to air pollution.

A study conducted in Sydney, found even low levels of air pollution (by world standards) are associated with increased risk of premature mortality, further the evidence that there is no safe level of air pollution.

Asthma ED visits increase at higher PM2.5 concentrations, with children more susceptible to the impacts than adults. ED visits due to PM2.5 were higher during the warm season.

Few studies investigate the influence of long-term exposure to low-level PM2.5 on cause-specific mortality, particularly for the concentrations consistently well below the current WHO annual standard. This study found long-term exposure to PM2.5 was associated with total, non-accidental, cardiovascular, and respiratory mortality in Queensland, Australia, where PM2.5 levels were measured well below the WHO air quality standard.