In a groundbreaking study conducted by UCLA Health, researchers have unveiled the significant environmental impact of inhalers used by millions of asthma and COPD patients across the United States. Despite their critical role in managing respiratory diseases, inhalers contribute substantially to greenhouse gas emissions, raising urgent questions about their sustainability. This study represents the most comprehensive quantification of inhaler-related emissions in the U.S. to date, shedding light on a previously underappreciated source of carbon pollution.
According to the findings, inhalers have been responsible for emitting over 2 million metric tons of carbon dioxide annually over the last ten years. To put this into perspective, the emissions generated by these devices are comparable to those produced by approximately 530,000 gasoline-powered cars operating on American roads each year. This startling equivalence highlights the vast scale at which inhaler emissions impact the environment and compels healthcare systems to reconsider current treatment paradigms.
The researchers meticulously analyzed emissions across the three inhaler types approved for asthma and COPD: metered-dose inhalers (MDIs), dry powder inhalers (DPIs), and soft mist inhalers (SMIs). Their results indicate that MDIs are overwhelmingly responsible for the carbon burden, accounting for 98 percent of the total greenhouse gas emissions during the decade under study. This dominance is primarily driven by the hydrofluoroalkane (HFA) propellants used in MDIs—substances well-known for their potent global warming potential relative to carbon dioxide.
HFAs, which replaced chlorofluorocarbons (CFCs) following environmental regulations, remain potent greenhouse gases themselves. While essential for delivering medication effectively in MDIs, their environmental footprint is significant. In contrast, DPIs and SMIs operate without propellants, utilizing the patient’s own breath to disperse medication particles. This critical distinction results in markedly lower emissions for these devices, positioning them as key candidates for greener respiratory care solutions.
Dr. William Feldman, a pulmonologist and lead author affiliated with the David Geffen School of Medicine at UCLA, contextualizes these findings within the broader healthcare landscape. He emphasizes that the carbon footprint of inhalers adds to the already substantial environmental impact of the U.S. healthcare system. Importantly, Feldman highlights that patient care need not be compromised, as there exists substantial opportunity to adopt greener inhaler technologies without sacrificing therapeutic effectiveness.
The team’s approach involved leveraging a comprehensive U.S. prescription database, capturing detailed National Drug Code (NDC) level data to estimate inhaler usage patterns. Their methodology integrated validated academic models to calculate emissions associated with different device types, propellants, therapeutic classes, branded products, manufacturers, payers, and pharmacy benefit managers. This data-driven analysis provides a granular understanding of emission sources across the inhaler ecosystem, from prescription to patient use.
Their analysis reveals disparities in emissions linked to product branding and manufacturer choices, indicating potential leverage points for policy interventions and market incentives. For example, branded inhalers often rely heavily on MDIs with high-albedo HFAs, suggesting pharmaceutical companies might lead the transition to low-emission alternatives by modifying their product portfolios or investing in innovative propellant technologies.
Looking ahead, the research team aims to deepen their investigations by focusing on specific patient populations, such as individuals covered under Medicaid, to explore both environmental and health outcome correlations. Additionally, they plan to undertake comparative effectiveness research examining clinical results between low-emission and conventional inhalers within identical therapeutic classes, further elucidating the balance between sustainability and patient well-being.
Another critical facet of future work includes dissecting the economic dynamics surrounding inhalers. Patent strategies and pricing models employed by pharmaceutical firms may influence the pace of adoption for greener inhaler technologies. Understanding these market forces will be instrumental in crafting regulatory frameworks and incentives that accelerate the shift toward environmentally responsible respiratory treatments.
Dr. Feldman underscores the essence of this investigation as a vital step in comprehending the magnitude of emissions driven by inhalers. Awareness and data transparency form the foundation upon which targeted mitigation strategies can be constructed, fostering synergy between public health goals and environmental stewardship. This dual-benefit approach aligns with escalating global concerns about climate change and the healthcare sector’s role in sustainable practices.
Inhaler emissions, while comparatively overlooked, represent a tangible contribution to anthropogenic greenhouse gases, spotlighting the intersection of medicine and climate policy. The UCLA findings suggest that shifting clinical practice toward wider adoption of DPIs and SMIs could serve as a pragmatic approach to reduce carbon footprints without compromising therapeutic efficacy or patient adherence.
By quantifying inhaler-related emissions at such scale and detail, this study sets the stage for multi-disciplinary dialogue among healthcare providers, environmental scientists, policy makers, and industry stakeholders. Collective action informed by robust scientific evidence will be critical to balancing urgent patient needs with the imperative of minimizing environmental harm inflicted by medical devices.
Ultimately, the UCLA Health study signals a pivotal moment for respiratory care, emphasizing innovation and responsibility. As the healthcare community grapples with the challenges posed by climate change, inhalers—once seen solely as life-saving tools—must now also be assessed through an environmental lens to ensure a healthier future for both patients and the planet.
Subject of Research: Not applicable
Article Title: UCLA Health Study Finds Inhalers for Asthma and COPD Drive Significant Greenhouse Gas Emissions
Web References: http://dx.doi.org/10.1001/jama.2025.16524
References: JAMA, 2025
Keywords: Greenhouse gases
