No matter how well you look after your mobile phone, it will always be covered with traces of molecules and bacteria. According to a new study, this means our phones say a lot more about our health and lifestyle than you might think.
The University of California San Diego's research, published in the journal Proceedings of the National Academy of Sciences, examined over 500 samples taken from 39 adults' mobile phones and hands.
The samples were compared to molecules identified in a database to produce a "lifestyle profile" of each phone owner. This analysis revealed surprising information about the person's lifestyle choices, including whether they preferred wine or beer and the type of products they used.
"By analysing the molecules they left behind on their phones, we could tell if a person is likely to be female, uses high-end cosmetics, dyes her hair, drinks coffee, prefers beer over wine, likes spicy food, is being treated for depression, wears sunscreen and bug spray - and therefore likely to spend a lot of time outdoors - all kinds of things," Dr Amina Bouslimani, an assistant project scientist, said.
It's thought that the majority of the molecules are transferred to phones from people's skin, hands and sweat and yes, personal hygiene plays a big part. People who don't wash every day are more likely to have traces of beauty products on their skin.
It might sound a little intrusive, but the revealing research could be particularly helpful to investigators.
"You can imagine a scenario where a crime scene investigator comes across a personal object - like a phone, pen or key - without fingerprints or DNA, or with prints or DNA not found in the database," senior author Dr Pieter Dorrenstein explained to Science Daily.
"So we thought - what if we take advantage of left-behind skin chemistry to tell us what kind of lifestyle this person has?"
Who knew the grime on our phones could be so important?