Research Publications

Metered-dose inhalers prescribed for asthma and chronic obstructive pulmonary disease contain hydrofluorocarbon propellants, potent greenhouse gases that trap heat in the atmosphere thousands of times more powerfully than carbon dioxide. In England, these inhalers contribute an estimated 0.8 million metric tons (MMT) of annual carbon dioxide equivalent (CO₂e) emissions,¹ equivalent to 157 885 US homes’ yearly electricity use.² In response, the National Health Service (NHS) has encouraged switching from propellant-containing metered-dose inhalers to propellant-free alternatives such as dry-powder and soft-mist inhalers.¹

The US health care system produces 550 MMT of CO₂e emissions annually³ vs 30.4 MMT of CO₂e for NHS England,¹ yet efforts to reduce inhaler-related emissions in the US have been hindered by limited data on the carbon footprint of US inhalers. We assessed mean emissions and costs and estimated total yearly emissions and costs for US brand-name inhalers prescribed to Medicare Part D and Medicaid beneficiaries. Medicare Part D and Medicaid account for approximately 40% of US retail prescription drug spending.⁴