BIRMINGHAM, England -- In kitchens worldwide, cooking oils sizzle and splash, releasing invisible particles into the air. While many of us rely on extractor fans to whisk away these cooking fumes, new research suggests these airborne particles don't just disappear into thin air. Instead, scientists say they reorganize themselves into complex architectural structures that could influence both air quality and climate.
The new study published in Atmospheric Chemistry and Physics reveals how these airborne cooking fats reorganize themselves at the molecular level, potentially protecting harmful urban emissions and affecting cloud formation.
Scientists from multiple British universities, led by researchers at the University of Birmingham, investigated how fatty acids -- particularly oleic acid, a common component in cooking oils and sea spray -- behave when released into the atmosphere. Their findings suggest that these compounds don't simply float around as individual molecules but instead form complex structures that can trap water and resist chemical breakdown.
Picture building blocks that can arrange themselves in different patterns. These fatty acid molecules can stack like plates, form cylindrical tubes, or cluster into spherical shapes depending on environmental conditions. The research team discovered that adding sugar (specifically fructose) to these fatty substances caused them to adopt different architectural arrangements at the molecular scale.
Working at Diamond Light Source's I22 beamline, alongside experts from the Central Laser Facility at the Rutherford Appleton Laboratory, researchers observed these molecular arrangements in real time. Using sophisticated X-ray techniques, they tracked how the structures changed under varying humidity levels and exposure to ozone, a common atmospheric oxidant.
This approach revealed something surprising: these particles could absorb substantially more water than simple models had previously suggested. Scientists say that as these droplets take on more water, they become heavier, eventually falling as rain and being removed from the atmosphere. However, the study revealed a complex dynamic where particles can reform into different three-dimensional structures even as they break down, each with varying abilities to absorb water and react with other chemicals.
Perhaps most intriguingly, certain molecular arrangements made the fatty acids more resistant to chemical breakdown by ozone, which typically destroys these compounds in the atmosphere. This finding helps explain a long-standing mystery: why cooking-related fatty acids persist longer in real urban environments than laboratory studies would predict.
The implications extend beyond just understanding atmospheric chemistry. For city planners and public health officials, this research highlights the importance of proper ventilation in urban environments. "To reduce exposure to pollutants from cooking, people should consider making more use of extractor fans and ensuring that kitchens are well ventilated to allow aerosol particles to escape rapidly," says lead researcher Christian Pfrang in a statement.
The research also emphasizes the dynamic nature of these atmospheric particles.
"Our results show that aerosols exist in a really dynamic state, with complex structures being formed as well as being destroyed. Each of these states allows polluting molecules to linger in the atmosphere for longer," explains Pfrang.
From sizzling pan to atmospheric particle, the journey of cooking fats shows how sometimes the most mundane substances harbor the most sophisticated secrets. Each pan sends forth not just the aroma of dinner, but participants in an atmospheric journey that could influence our environment in ways both subtle and profound.