Household aerosols such as air fresheners, deodorants and furniture polish have overtaken cars as a source of smog polluting chemicals in the UK, a new study has found.
It has led to scientists urging people to swap these products for the likes of roll-on deodorant and hair gel – as small changes can lead to large changes in air quality.
Researchers looked into the emission of volatile organic compounds (VOCs) – the chemicals found in aerosol sprays – which are less damaging than chlorofluorocarbons that they replaced in the 1980s.
However, these chemicals can cause photochemical smog when combined with nitrogen oxide in sunlight.
While vehicles were responsible for most VOC emissions into the 2000s, scientists found that the use of catalytic converters on vehicles and fuel vapour recovery at filling stations has led to a rapid decline.
In contrast, 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.
Currently, VOCs are used in around 93% of all aerosols, the study said.
Researchers are now calling for the use of less damaging nitrogen as a propellant, as well as a wider awareness of how polluting VOCs can be.
The paper, published in Elementa: Science of the Anthropocene, revealed that the world’s population now uses more than 25 billion cans per year – which is estimated to lead to the release of 1.3 million tonnes of VOC air pollution annually.
This could rise to 2.2 million tonnes of VOC air by 2050 – leading to calls for people to switch products.
Professor Alastair Lewis, a director of the National Centre for Atmospheric Science in Leeds, 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."
"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," he added.