**Your Asthma Inhaler Might Not Be Good for the Environment**
*By Dwaipayan Roy | Oct 07, 2025, 08:03 PM*
A recent study has revealed that inhalers used to treat asthma and chronic obstructive pulmonary disease (COPD) contribute significantly to greenhouse gas emissions. Researchers from the University of California and Harvard University found that these devices produce annual emissions equivalent to those of over half a million petrol-powered cars in the US alone. The findings were published in the *Journal of the American Medical Association*.
### Emission Sources: Metered-Dose Inhalers Most Damaging
The study examined global warming pollution from three types of inhalers between 2014 and 2024. It found that metered-dose inhalers (MDIs), which use hydrofluoroalkane (HFA) propellants to deliver medication, were responsible for a staggering 98% of emissions during the decade.
In total, US patients covered by commercial insurance and government programs such as Medicaid and Medicare produced an estimated 24.9 million metric tons of carbon dioxide equivalent in this period.
### Eco-Friendly Alternatives Are Available but Underused
Unlike metered-dose inhalers, dry powder inhalers and soft mist inhalers do not use propellants. Dry powder inhalers release medication through the patient’s breath, while soft mist inhalers convert liquid medicine into a fine spray. These alternatives are much less harmful to the environment.
However, lead author William Feldman from UCLA pointed out that only a small fraction of patients currently require metered-dose inhalers, implying many could switch to more eco-friendly options.
### Accessibility Issues: Insurance and Market Barriers
Feldman noted that most patients could safely use dry powder or soft mist inhalers, but insurance coverage and market availability have slowed their adoption in the US. For example, a dry-powder version of albuterol—the most commonly used inhaler drug—is available but often not covered by insurance.
Similarly, budesonide-formoterol, a widely used medication in dry powder form across Europe, is not yet available in the American market.
### Advocacy for Policy and Pricing Reform
Feldman emphasized that the goal of the research is not to blame patients but to call for necessary policy reforms. A related commentary in *JAMA* by Alexander Rabin from the University of Michigan echoed this message, urging insurers and policymakers to make low-emission inhalers affordable and accessible to everyone.
As awareness of environmental impacts grows, increasing adoption of greener inhaler alternatives may be crucial for reducing healthcare-related emissions while continuing to provide effective treatment for respiratory conditions.
https://www.newsbytesapp.com/news/science/asthma-inhalers-pollute-as-much-as-half-a-million-cars/story