There’s a “secret world” inside your microwave.

A study from the University of Valencia has discovered colonies of bacteria living inside several microwave ovens. When heating food, it is common for a little bit of it to splash, and our hands can also transfer bacteria when handling the appliance. The long-held belief that microwave radiation kills all bacteria is actually a myth, comparable to the idea that mango milk is bad for you or that it is safe to eat food that falls to the floor in less than three seconds.

The study, published in the journal Frontiers in Microbiology, revealed that bacteria don’t just live inside microwave ovens, but also form entire ecosystems. The scientists collected samples from 30 microwaves from homes, workplaces, and laboratories. After growing the samples in Petri dishes and sequencing the DNA, they identified 101 bacterial strains. The most common bacteria belong to the genera Bacillus, Micrococcus, and Staphylococcus, which are commonly found on human skin and frequently touched surfaces.

Human skin bacteria were found in all types of microwaves, and were most abundant in household and communal appliances. Some bacteria associated with foodborne illness, such as Klebsiella and Brevondimonas, were also found in some household microwaves. The researchers suggest that these bacteria have undergone “natural selection,” with the most microwave-resistant surviving bacteria being classified as extreme organisms.

Despite the presence of these bacteria, scientists say that none of them are very harmful to human health, so there is no need to worry. However, it is recommended that you clean your microwave regularly, just as we clean your kitchen floor and cupboards. The same advice applies to microwaves in work environments. So, how about starting to clean your microwave now?

Information from nature.