A bacon, egg and cheese scone. Picture: Pexels

Cooking a full English breakfast or a stir fry could be as bad for your lungs as your diet, a study suggests.

This is because the hot oil sends tiny droplets of fat into the air, which may be ‘hazardous’ if breathed in.

The explosion of microscopic particles, caused by a reaction between oil and water, could contribute towards indoor air pollution, which is thought to kill millions each year.

Scientists at Texas Tech and Utah State universities heated a pan of oil and recorded what happened when small amounts of water were dropped in. As the water vaporises in the pan, the oil becomes ‘explosive’ and sends tiny droplets flying into the air.

The potentially hazardous particles, which are almost invisible, can then be breathed in if the kitchen is not properly ventilated.

Assistant professor Jeremy Marston, from Texas Tech, said: ‘Regardless of culinary skills, most people who have used a stove top have encountered the result of water interacting with hot oil.

‘We’ve discovered that a very large number of small oil droplets are released when even a single, small droplet of water comes into contact with hot oil.’

Chicken, which has a high water content, is one of the worst offenders along with many other vegetables used in Chinese cooking.

Prof Marston said: ‘It’s known that millions of deaths worldwide occur due to indoor air pollution, but we don’t know yet how much cooking in poorly ventilated kitchens contributes to it.’