Understanding inhaler users’ perceptions of climate change and inhaler carbon footprints: insights from a Canadian survey

BACKGROUND: People with lung diseases are vulnerable to climate change, yet metered dose inhalers (MDIs) have significant climate impacts. We sought to understand inhaler users' perspectives on climate change and awareness of inhaler climate implications. METHODS: Canadians (aged ≥16 years) who reported using an inhaler in the previous 6 months were invited via health organisations' newsletters to complete an online survey (November 2024-March 2025). Multivariate regression models assessed the association between sociodemographic factors and climate change risk perception, disposal practices and awareness of inhaler climate implications. RESULTS: There were 343 respondents (median age 71 years (IQR: 64-76 years), 65% female, 80% MDI users). Individuals were concerned (45%) or very concerned (39%) about climate change, but only 20% were previously aware of inhaler climate implications. Advancing age (OR 0.58, 95% CI 0.45 to 0.74) was associated with being unaware of inhaler climate implications, while a university education (OR 4.86, 95% CI 1.77 to 16.62) and living in a large urban area (OR 2.81, 95% CI 1.21 to 7.45) were associated with greater awareness. Most respondents reported disposing of their inhalers in garbage or recycling bins (70%) and provincial pharmacy return programmes were underused (27%) when available. Nearly all MDI users (92%) were willing to switch to a lower carbon footprint device. Advice from healthcare providers was valued in supporting treatment decisions. INTERPRETATION: Inhaler users are concerned about climate change but lack awareness of inhaler climate impacts. Sustainability interventions that promote education, safe use of low carbon devices and recycling could reduce inhaler-related climate impacts.