Singapore study finds link between asthma control and lower carbon emissions

SINGAPORE: A team from SingHealth Polyclinics has found a strong link between asthma severity and carbon emissions, discovering that better asthma control can actually help reduce environmental impact.

The researchers analysed data from more than 23,000 asthma patients treated across its nine polyclinics between 2015 and 2023 and examined the carbon footprint of various inhaled asthma medications.

They found that patients with more severe asthma, who rely on both long-term and fast-acting medications, tend to emit significantly higher amounts of carbon dioxide. This is due to the extensive use of inhaled medications over time, particularly those administered via pressurised metered-dose inhalers, which have the highest carbon emissions in asthma treatment.

Carbon emissions from patients using a combination of steroid inhalers and long-acting beta-agonists — commonly known as long-term controllers — rose from 107 tonnes in 2015 to 368 tonnes in 2023. When fast-acting “rescue” inhalers were added for sudden asthma attacks, emissions increased further, with the study estimating that combination therapy could produce up to 767 tonnes of carbon dioxide.

Despite the overall increase in total emissions from long-term therapy, the average annual carbon emissions per patient have declined over the same period and fell from 179 kg in 2015 to 121 kg in 2023. This reduction is equivalent to cutting the carbon emissions generated by a car driving about 2,500 kilometres.

Clinical Associate Professor Tan Ngiap Chuan, director of research and Primary Care Research Institute at SingHealth Polyclinics, said the results highlight the dual benefits of proper asthma management.

“We have been educating patients on the importance of continuous use of long-acting asthma medications. This is what we call long-term controller therapy,” said Assoc Prof Tan, “With fewer asthma exacerbations and improved asthma control, the use of various chemical rescue medications is reduced, significantly reducing greenhouse gas emissions and carbon footprint.”

SingHealth said it hopes the study will raise awareness among asthma patients that managing their condition effectively not only improves their well-being but also contributes to a smaller environmental footprint.