Aerosols overtake cars as source of smog pollution, York Uni research suggests
The study led to calls for people to use roll-on deodorant and hair gel, with small lifestyle changes potentially leading to large changes in air quality
Household aerosols - including deodorants, air fresheners and furniture polish - have overtaken cars as a source of polluting smog chemicals in the UK, research from the University of York suggests.
The study led to calls for people to use roll-on deodorant and hair gel, with small lifestyle changes potentially leading to large changes in air quality.
Researchers looked into the emission of volatile organic compounds (VOCs) which are less damaging than chlorofluorocarbons that they replaced in the 1980s but can cause photochemical smog when combined with nitrogen oxide in sunlight.
They found that while vehicles were responsible for most VOC emissions into the 2000s, the use of catalytic converters on vehicles and fuel vapour recovery at filling stations has led to a rapid decline.
Conversely, the global amount of VOCs emitted from aerosols every year is rising as lower and middle-income economies grow and people in these countries increase their consumption.
The world's population now uses more than 25 billion cans per year and this is estimated to lead to the release of 1.3 million tonnes of VOC air pollution annually, and could rise to 2.2 million tonnes by 2050.
The paper, published in Elementa: Science of the Anthropocene, said the UK emitted around 60,000 tonnes of VOCs from aerosols in 2017, around double the amount from cars running on petrol.
Professor Alastair Lewis, a Director of the National Centre for Atmospheric Science, said: "Virtually all aerosol based consumer products can be delivered in non-aerosol form, for example as dry or roll-on deodorants, bars of polish not spray.
"Making just small changes in what we buy could have a major impact on both outdoor and indoor air quality, and have relatively little impact on our lives.''
The University of York academic added: "The widespread switching of aerosol propellant with non-VOC alternatives would lead to potentially meaningful reductions in surface ozone.
"Given the contribution of VOCs to ground-level pollution, international policy revision is required and the continued support of VOCs as a preferred replacement for halocarbons is potentially not sustainable for aerosol products longer term.''
VOCs are currently used in around 93% of all aerosols, the study said, with researchers calling for the use of less damaging nitrogen as a propellant and wider awareness of how polluting VOCs can be.
Professor Lewis said: "Labelling of consumer products as high VOC emitting - and clearly linking this to poor indoor and outdoor air quality - may drive change away from aerosols to their alternatives, as has been seen previously with the successful labelling of paints and varnishes.''