Taking a swab of your cell phone screen may be able to tell a lot of information about a person, including diet, health status, preferred hygiene products and locations visited.
Researchers at the University of California San Diego School of Medicine and Skaggs School of Pharmacy and Pharmaceutical were able to construct lifestyle sketches for phone owners by examining the trace chemicals, molecules and microbes on the phones.
Senior author Pieter Dorrestein, Ph.D., professor in UC San Diego School of Medicine and Skaggs School of Pharmacy and Pharmaceutical Sciences, said this information could have a number of applications including criminal profiling, airport screening, medication adherence monitoring, clinical trial participant stratification and environmental exposure studies.
“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. They would have nothing to go on to determine who that belongs to,” he said in a statement.
“So we thought — what if we take advantage of left-behind skin chemistry to tell us what kind of lifestyle this person has?”
During the study, 39 healthy adults volunteered to have their cell phone swabbed at four spots and their right hand swabbed at eight spots.
Dorrestein’s team then used a technique called mass spectrometry to detect molecules from the samples.
They were able to identify as many molecules as possible by comparing them to reference structures in the GNPS Database a crowdsourced mass spectrometry knowledge repository and annotation website developed by Dorrestein and co-author Nuno Bandeira, Ph.D., associate professor at the Jacobs School of Engineering and Skaggs School of Pharmacy and Pharmaceutical Sciences at UC San Diego.
The researchers used this information to develop a personalized lifestyle read out from each phone.
They were able to detect some of the medications on the phones including anti-inflammatory and anti-fungal skin creams, hair loss treatments, anti-depressants and eye drops.
Some food molecules included citrus, caffeine, herbs and spices. Sunscreen ingredients and DEET mosquito repellant were also detected on the phones, despite some volunteers not using the products in several months prior to the experiment.
“By analyzing the molecules they’ve left behind on their phones, we could tell if a person is likely 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 spends a lot of time outdoors—all kinds of things,” first author Amina Bouslimani, Ph.D., an assistant project scientist in Dorrestein’s lab, said in a statement. “This is the kind of information that could help an investigator narrow down the search for an object’s owner.”
According to Dorrestein, the molecular read-outs provide a general profile of a person’s lifestyle but they are not meant to be a one-to-one match like a fingerprint.
In a previous study, Dorrestein’s team constructed 3D models to illustrate the molecules and microbes found at hundreds of locations on the bodies of two healthy adult volunteers.
Despite each volunteer agreeing to a three-day moratorium on personal hygiene products before samples were collected for the 2015 study, the researchers observed that the most abundant molecular features in the skin swabs still came from hygiene and beauty products like sunscreen.
“All of these chemical traces on our bodies can transfer to objects,” Dorrestein said. “So we realized we could probably come up with a profile of a person’s lifestyle based on chemistries we can detect on objects they frequently use.”
Dorrestein and Bouslimani have begun to extend their study with an additional 80 people and samples from other personal objects, such as wallets and keys.
The study was published in the Proceedings of the National Academy of Sciences of the United States of America.