Researchers urge insurance and policy reforms to promote greener alternatives
The inhalers millions of Americans rely on to breathe are quietly contributing to global warming on a massive scale — generating annual greenhouse gas emissions equivalent to more than 530,000 cars, according to a new study published Monday in the Journal of the American Medical Association (JAMA).
Researchers from the University of California, Los Angeles (UCLA) and Harvard University analyzed national drug databases covering inhaler use between 2014 and 2024. They found that inhalers prescribed to patients covered by commercial insurance, Medicaid, and Medicare produced a staggering 24.9 million metric tons of carbon dioxide equivalent over the decade.
Metered-dose inhalers, commonly known as “puffers,” accounted for 98% of these emissions. These devices rely on pressurized hydrofluoroalkane (HFA) propellants—potent greenhouse gases—to deliver medication. By contrast, dry powder and soft mist inhalers, which use either patient inhalation or a fine liquid spray, emit far less and offer equivalent medical outcomes for most patients.
“Five hundred and thirty thousand cars on the road each year is a lot,” lead author Dr. William Feldman, a pulmonologist and researcher at UCLA, told AFP. “This is a really important topic because it’s fixable — there are easy ways to reduce emissions.”
Medically, only a small percentage of patients require metered-dose inhalers, such as very young children who need spacers or frail seniors with limited lung capacity. But Feldman noted that the vast majority could safely use dry powder or soft mist inhalers, as is already common in countries like Sweden and Japan.
However, the US has been slow to adopt these greener options due to insurance and market barriers. For example, while a dry-powder version of albuterol — the most commonly used inhaler drug — exists, it is often not covered by insurance and costs significantly more. Another widely used dry-powder drug in Europe, budesonide-formoterol, isn’t even available in the US market.
Feldman stressed that the intent of the study is not to blame patients but to push for systemic change. “We absolutely do not want to stigmatize patients with asthma and COPD,” he said. “It’s incumbent upon us as a society to get those medications to the patients in a sustainable way, and that ultimately falls to the highest levels.”
In a related commentary, Alexander Rabin of the University of Michigan and colleagues warned that several low-global-warming metered-dose inhalers are expected to enter the US market soon as high-priced, brand-name drugs. Without policy interventions, they cautioned, patients without strong insurance coverage could be left behind.
The study highlights a growing intersection between public health and climate policy, calling for insurance reform and regulatory action to make low-emission inhalers more affordable and accessible.