(CNN)Asthma sufferers could sharply reduce their carbon footprint by swapping commonly used inhalers for "greener" alternatives, a study from the University of Cambridge has found.
Asthma patients could slash their carbon footprint by switching to 'greener' inhalers
By swapping metered-dose inhalers for dry powder inhalers, users could reduce their carbon emissions equivalent to reducing their meat consumption or recycling, researchers said Wednesday.
But patients have been warned not to make such changes without medical advice.
Inhalers are used to treat the symptoms of conditions such as asthma by releasing medicine straight into a patient's lungs, widening the airways and making it easier to breathe.
Metered-dose inhalers contain liquified, compressed gas hydrofluoroalkane (HFA) -- a greenhouse gas -- which acts as a propellant to atomize the drug being delivered and to pump it out to the user.
Seven out of 10 of the 50 million inhalers prescribed in England in 2017 were metered-dose inhalers.
Researchers found that these metered-dose inhalers contribute 3.9% of the carbon footprint of the UK's National Health Service (NHS).
Alternative "greener" treatments, such as dry powder inhalers and aqueous mist inhalers, are available, experts said in the study published in BMJ Open.
But the higher up-front price of some dry powder inhalers was a "significant barrier" when moving to such alternatives.
Researchers found that the carbon footprints of metered-dose inhalers were up to 37 times those of dry powder inhalers.
Replacing 10% of metered-dose inhalers in England with the cheapest dry powder equivalents would reduce greenhouse gas emissions by the equivalent of 58 kilotonnes of CO2, the scientists said.