​Environmental impact of respiratory care
Greenhouse gases and inhalers
Reducing greenhouse gas (GHG) emissions has become increasingly important to governments worldwide, as they are a major contributor to global warming and climate change. Carbon dioxide (CO2) is a significant GHG as it absorbs and re-radiates heat, warming the planet. The global warming potential (GWP) of other gases are expressed in terms of CO2 equivalence (CO2eq).[34] For example, a typical short-acting reliever pressurized metered dose inhaler (pMDI) – the blue inhaler - has a carbon footprint of approximately 28 kg CO2 eq.[35] Globally, short-acting reliever use/overuse is the greatest contributor to the carbon footprint of respiratory treatment, estimated at 2.7 million tonnes CO2 eq, accounting for 70% of total inhaler related emissions.[36] By contrast, a typical outpatient visit uses 6.94 kg CO2 eq, compared to 57.7 kg CO2 eq for an emergency department visit (by ambulance) and 115.1 kg CO2 eq for a 3-day hospital admission.[35] Hospitalizations due to chronic obstructive lung disease (COPD) are typically much longer.[37]
We all want to do our bit for the environment. While it’s important to take account of all our GHG emissions, the carbon footprint of a pMDI should be contextualized with the following information:
-
The absolute contribution of pMDIs to global warming is very small, estimated to account for <0.1% of total GHG emissions.[38]
-
Propellants used in pMDIs are short-lived gases and cannot accumulate in the atmosphere beyond their lifetime.[34]
-
Removing pMDIs as a choice of inhaler will have no net impact on climate or the trajectory of global warming.[34]
-
Addressing the problem of global warming is mainly about promoting a change in patterns of use of fossil fuel consumption, travel and diet. Changes in respiratory care patterns are only a small piece of the puzzle.[32]
-
That being said, substantial reductions in the carbon footprint of pMDIs can be achieved with transition to low GWP propellant inhalers.[3, 4] Pressurized MDIs with next generation propellants are currently being developed.
pMDI propellants – the transition to greener alternatives
Pressurised MDIs use propellants to generate the force necessary to deliver drugs deep into the lungs.[14] Early propellants such as chlorofluorocarbons (CFCs) have gradually been phased out following the Montreal Protocol in 1987 due to their ozone-depleting properties.[32, 39] CFC propellants were replaced by fluorinated gases (F-gases) including hydrofluoroalkane (HFA)-134a and HFA-227ea. Although these HFAs have no ozone-depleting potential, they have a high GWP,[3] and so they are also being phased out.[5, 40] In response to this phase out, pMDIs are being developed which contain ‘greener’ low GWP propellants: HFA-152a and hydrofluoroolefin (HFO)-1234ze.[3, 4, 31] These ‘greener’ propellants are on track to become available from the end of 2025 which will significantly reduce GHG emissions from pMDIs.[4]
Transition to low GWP propellant pMDIs is better for the environment than switching to a different device type while also preserving patient access and choice, thus giving better treatment and outcomes.[41]
Reducing the environmental impact of inhalers in respiratory care
The intervention that would do the most to reduce the impact of respiratory treatments on climate change is improving standards of care for patients living with chronic respiratory disease.[32] ‘Green’ healthcare should also consider the waste and environmental damage caused by poorly managed asthma and COPD.[32] We can all play our part in protecting the environment.
Some simple steps to reduce the environmental impact of inhalers in respiratory care include:[32]
-
Improve asthma control and reduce use of short-acting reliever therapy (e.g. blue inhaler) by using regular preventer treatment by every means possible.
-
Improve COPD control and reduce use of short-acting reliever therapy (e.g. blue inhaler)
-
Use inhalers with good adherence and correctly
-
Use spacers with pMDIs to increase clinical effectiveness
-
Choose pMDIs which minimize propellant quantity
-
Ensure patients have a pMDI and spacer for emergency treatment
-
Ensure pMDIs are not discarded before they are empty
-
Where required, combine multiple medicines in one device (fixed dose combinations)
-
Promote inhaler recycling
