Intimate details of a person's lifestyle, shopping habits and health can now be gleaned from the molecules they leave behind on everyday objects such as smartphones, pens or keys, scientists have proven.
US researchers took swabs from the mobile phones of 39 volunteers and used a technique called mass spectrometry to identify individual molecules and compounds on the case and screen.
They then compared them to the Global Natural Product Social Molecular Networking database, which records the chemical make-up of thousands of products and drugs to reveal a unique profile of each owner.
The team was able to tell the sex of the owner as well as a host of private information.
This included whether they were suffering from depression, skin inflammation or allergies, based on medications which were present.
They could also tell whether a person preferred wine or beer.
The study was also able to tell what cosmetics they used, if the person dyed their hair or were bald, and if they spent a lot of time outdoors.
If was even possible to tell if they liked spicy food.
The profiling could be useful for identifying suspects or victims in criminal cases, or even profiling people at airports, say researchers.
The research was published in the journal 'Proceedings of the National Academy of Sciences'.