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New studies reveal environmental toll of commonly used inhalers

Published Date

Over a 10-year period, research shows inhalers produced nearly 25 million metric tons of CO₂ equivalent emissions

RENTON, Wash. [October 29, 2025] - Inhalers for lung conditions like asthma and emphysema are among the most commonly prescribed medications, and recent studies show they uniquely contribute to the health sector’s carbon footprint.

Two studies supervised by Brian Chesebro, M.D., medical director for the Providence Center for Environmental Stewardship, and published in the October issue of JAMA, provide a detailed national context of inhaler-related emissions in the U.S. over the past decade. They give an example for how health systems could assess their practices and identify opportunities to drive down these emissions.     

“We want to add the perspective of the environmental cost of these devices to be factored alongside other important considerations of value,” Dr. Chesebro said of the studies. “The goal is to move toward inhaled medications that are safe, effective, available, easy to use and with the lowest environmental impact.”

Metered-dose inhalers use a propellant to deliver a dose of medication into the patient’s lungs, while other types of inhalers administer dry powder or soft mist medications that avoid the use of hydrofluorocarbon propellants. These hydrofluorocarbons, also used for refrigerants and air conditioning in other industries, are greenhouse gases thousands of times more potent than carbon dioxide. 

“We’ve been concerned about the propellants in these devices because they’re such potent greenhouse gases,” Dr. Chesebro said. “Broadly speaking, our team is focused on identifying and addressing health care-specific emissions, so this was a pretty clear target.”

Together, the studies showed that:

  • Nationwide, all inhalers produced nearly 25 million metric tons of carbon dioxide equivalent emissions from 2014 to 2024, with propellant-containing metered-dose inhalers responsible for 98% of emissions.  Overall, these inhaler-related emissions are comparable to the emissions from burning 2.8 billion gallons of gasoline. 

  • Within the VA health system, inhaler emissions dropped about 68% between 2008 and 2023, due to societal policy and VA-specific formulary changes that favored lower-emission inhalers, demonstrating that mitigation is possible.

“We need to understand in greater detail how to best balance the clinical, financial and environmental impacts of these devices in the treatment of specific patients and populations,” Dr. Chesebro said. “By acknowledging and measuring the environmental costs, we can expand our analysis to further optimize our clinical practices.”