Pollution from frying food survives in your kitchen for several days, scientists warned, announcing their discovery of why fatty particles linger for longer.
Researchers at the University of Birmingham said they had unlocked the mystery of why pollution from cooking with fat seemed to hang around in the air for days longer than other types.
Indoor air pollution from cooking is increasingly being raised as a risk to people’s health. Gas hobs also release nitrogen dioxide and carbon monoxide, with many people exposed indoors to levels of dirty air that would be illegal outdoors.
Scientists recommend using an extractor fan or opening windows to reduce these levels, but the paper, published in the journal Faraday Discussions, suggests that this pollution is also an issue for the wider atmosphere.
The team also said that policymakers should consider regulating pollution created by fast-food restaurants, which is not currently taken into account.
In the UK up to 10 per cent of air pollution is thought to come from this source, rising to up to 39 per cent in Hong Kong and 22 per cent in some of China’s cities.
Lead author Dr Christian Pfrang, of the University of Birmingham’s School of Geography, Earth and Environmental Sciences, said this was a particular issue when cooking with fat at high temperatures, such as deep-fat frying.
The pollution is caused by unsaturated fatty acids such as oleic acid, emitted when cooking with fat, which interact with water in the atmosphere.
This creates a crust preventing them from being broken down by ozone in the atmosphere, as normally happens with air pollution.
They can also join up with other substances including polycyclic aromatic hydrocarbons which are emitted by car exhausts and are carcinogenic, causing these to linger too.
The process could also affect the weather by affecting the ability of water droplets to form clouds.
Dr Pfrang added: “The implications of this should be taken into account in city planning, but we should also look at ways we can better regulate the ways air is filtered – particularly in fast food industries where regulations do not currently cover air quality impacts from cooking extractor emissions for example.”