Amina Bouslimani, University of California, San Diego, USA, and colleagues have developed an approach to translate chemical profiles recovered from personal objects such as phones into a lifestyle sketch of the owner. They took swabs from the hands of 39 subjects, as well as from four positions of their phones; two on the front and two on the back. All samples were analyzed for their chemical composition using a mass spectrometer.
From the compounds that were detected on the phones, the team could tell a person’s gender, whether he or she uses expensive cosmetics or colors his or her hair, and whether that person drinks beer or wine. The researchers could even determine if someone loves spicy food, is treated for depression, or uses sunscreen.
Some chemical compounds are transferred directly onto the skin by drinking, taking tablets, or hand washing, and then deposited onto the phone. These include certain soaps and cosmetics, drugs such as antifungal ointments or eye drops, but also residues of orange peels. Other substances come from sweat, including caffeine from morning coffee, degradation products of orally taken antidepressants, or alcohol residues. By combining these types of chemical clues, a personal profile of mobile phone owners can be created. The researchers even succeeded in assigning some of the mobile phones to their owners on the basis of these residues alone.
The residues remain detectable on the mobile phones for several months; sunscreen from the summer months, for example, may still be detected in the winter. According to the researchers, the findings could be used for criminal cases. The molecular lifestyle signatures could complement the traditional evidence of DNA and fingerprints.
- Lifestyle chemistries from phones for individual profiling,
Amina Bouslimani, Alexey V. Melnik, Zhenjiang Xu, Amnon Amir, Ricardo R. da Silva, Mingxun Wang, Nuno Bandeira, Theodore Alexandrov, Rob Knight, Pieter C. Dorrestein,
Proc. Natl. Acad. Sci. USA 2016.