When people think about healthcare’s contribution to climate change, images of energy-hungry hospitals and heaps of single-use medical supplies often come to mind. But few would suspect that a critical medical device for millions of people with asthma and COPD—asthma inhalers—could be silently exacerbating the climate crisis.
The Environmental Impact of Metered-Dose Inhalers
In discussions about health care's environmental impact, the role of asthma inhalers frequently goes unnoticed. However, researchers like Jyothi Tirumalasetty from Stanford University suggest that inhalers are a significant starting point for reducing emissions.
Metered-dose inhalers, commonly used for asthma and COPD, release medication through a propellant gas. These gases are typically hydrofluorocarbons (HFCs), which have a much greater capacity to trap heat compared to carbon dioxide, thereby contributing significantly to climate change.
Tirumalasetty, along with Shelie Miller from the University of Michigan, analysed 2022 data from Medicare and Medicaid, revealing that inhaler emissions equate to the annual energy consumption of a city the size of Milwaukee. The study found:
- Majority of Emissions: Metered-dose inhalers accounted for approximately 98% of inhaler-related emissions.
- Cost Implications: Environmentally friendly alternatives, such as dry powder inhalers, are less frequently prescribed but cost $2.5 billion more despite their lower emissions.
CFCs were removed from the market but were actively substituted by HCFCs. So far, the latter chemicals have not contributed to the destruction of the ozone layer, yet they are very potent greenhouse gases.
However, the potential for zero-emission propellants exists, but transitioning to these new inhalers could result in increased costs and insurance tier adjustments, making them less accessible initially.
Safety and Disposal Concerns
The use of inhalers based on HFCs is not dangerous from the standpoint of composition for people, as in the case of other inhalation usage it is an expelled majority of the propellants used. Nevertheless, about 30% of the propellant remains in the inhalers after use, which complicates their disposal.
Inhalers in the US are not confined within recycling closed loop systems on the large scale like in the case of the UK that utilizes these gases for other industries.