Estimating the national carbon footprint of inhalers in healthcare

Background Metered dose inhalers (MDIs) contain greenhouse gases which have a disproportionate effect on the carbon footprint of healthcare. There are more environmentally friendly alternatives such as dry powder inhalers (DPIs) or soft mist inhalers (SMIs). Aims This study aims to approximate the carbon footprint of inhalers dispensed in Irish healthcare. Methods Health Market Research data was used to examine the number of inhalers sold in Ireland in 2019 via dispensing data from pharmacy IT systems. The carbon footprint per inhaler data was then used to calculate the total carbon footprint of each drug class, and an estimate for the total carbon footprint of inhalers sold in Ireland was generated. Results 4,427,287 inhalers were dispensed in Ireland in 2019 of which 2,608,433 (59%) were MDIs and 1,818,854 were DPIs/SMIs (41.1%). The total carbon equivalent of these inhalers was estimated to be 54,765 tCO2. MDIs account for 59% of inhaler units dispensed but account for 97% of inhaler-related carbon emissions. Conclusion Targeting inhaler prescribing offers the potential to significantly improve the carbon footprint of Irish healthcare. Establishing the current carbon footprint of the inhalers that are prescribed, dispensed, and disposed in Ireland is a necessary baseline to inform moving towards a net zero health service.