Inhaled drugs and global warming: time to shift to dry powder inhalers.

Propellants in metered dose inhalers are powerful greenhouse gases It is five years since the Climate Change Act (2008) was introduced to ensure that by 2050 the United Kingdom cuts its carbon emissions by 80%. Despite this, atmospheric carbon dioxide levels have recently increased, passing the 400 parts per million mark. Although the potential impact of climate change on respiratory health is widely appreciated,1 it is less well known that respiratory drugs may be making a sizeable contribution to global warming because of the propellant gases used in metered dose inhalers. The NHS has an annual global warming potential of about 20 million tonnes of carbon dioxide equivalent (1 million tonnes of carbon dioxide is equivalent to 1000 kg or 55.6 billion L of carbon dioxide),2 which is about the same as that of Estonia. This constitutes about 3% of total UK emissions, which were 590 million tonnes of carbon dioxide equivalent in 2010. Of this, only 35% is accounted for by heating, lighting, and transport, with 65% being due to procurement—the delivery of healthcare, including drugs.2 Respiratory inhalers are some of the …