Deep frying food can have a negative impact on health, and not just through eating the oily food. Scientists in Europe have discovered that the sticky air above deep frying units could fuel smog and clouds, finding that fatty acid molecules make up about 10 percent of air particles over London.

When food is friend, the fatty acids that are released into the air coat the surface of particles in the atmosphere, allowing them to bind together easier and create more clouds. The researchers estimate that molecules like dust or salt that get coated in deep-fryer oil can remain in the atmosphere for between two and 24 hours.

“The molecules given off by deep fat frying is likely to have more of an effect on clouds than previously thought,” said lead researcher Adam Squires of the University of Bath. However, he cautioned that more research is required as the team’s research was done in a laboratory.