Climate change

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

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.

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.