If the idea of someone digging up dirt about you is a concern, WikiLeaks may be only part of your worries. The dirt you leave behind on your smartphone also can reveal information about what you've been up to, according to a new study. 
 
 By taking just a quick swab of the chemical residue on a smartphone, scientists at the University of California, San Diego, could construct a lifestyle sketch of the phone's owner, including his or her diet, health status, locations visited and even preferred hygiene products. 
 
 The researchers said they see a range of possible uses for such an analysis, from criminal profiling and forensics to health studies that monitor a person's exposure to toxins or adherence to a medicine regimen. [Body Bugs: 5 Surprising Facts About Your Microbiome] 
 
 The analysis, described today in the journal Proceedings of the National Academy of Sciences, may not be able to identify individuals as well as tests using DNA or fingerprints can (although these also could be left on a phone). But the dirt on your smartphone can paint a rather complete picture of your day-to-day activities, the researchers said. 
 
 "All of these chemical traces on our bodies can transfer to objects," said Pieter Dorrestein, a professor of pharmacology at the UC San Diego School of Medicine, who led the study. "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," such as the person's phone. 
 
 For this study, Dorrestein's team analyzed chemical traces left behind on the phones of 39 volunteers. Researchers swabbed four sections on each phone as well as eight spots on each study participant's right hand. The scientists then conducted a technique called mass spectrometry on each of the samples to determine the types of molecules present. [9 Odd Ways Your Tech Devices May Injure You] 
 
 Once the samples were analyzed, the researchers compared what they found with a massive database of molecules from various commercial products and medicines. Results showed traces of medicines such as hair-loss treatments, antidepressants, anti-fungal skin creams and anti-inflammatory drugs; food ingredients such as herbs, spices and caffeine; and products such as sunscreen and DEET mosquito repellant even months after these two types of items had last been used by the phone owners. 
 
 "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," said Amina Bouslimani, an assistant project scientist in Dorrestein's lab who was the first author on the paper. 
 
 Although the technique is in the early stages of development, it is fairly accurate and "can be used in [a criminal] investigation as … an assisting method of narrowing down the search to a smaller group of likely candidate people," Dorrestein told Live Science. 
 
 He said the technique can become more powerful as more molecules are added to the reference database, which his group has developed and expanded via crowdsourcing. Dorrestein added that the researchers are interested in the molecules of the most common foods, clothing materials, carpets, wall paints and anything else people come into contact with. 
 
 Dorrestein said that there could be a potential to analyze a person's gut microbes, which could reveal people's health status from traces of fecal matter that might be on the phone, although he didn't detect any in his study of 39 people. He said he is working with other scientists on the American Gut project to better understand the molecules and microbes in the human gut, to serve as another reference database. 
 
 The study was funded in part by the National Institute of Justice, which is the research, development and evaluation agency of the U.S. Department of Justice. 
 
 Follow Christopher Wanjek @wanjek for daily tweets on health and science with a humorous edge. Wanjek is the author of "Food at Work" and "Bad Medicine." His column, Bad Medicine, appears regularly on Live Science. ||||| MONDAY, Nov. 14, 2016 (HealthDay News) -- By analyzing chemicals, molecules and germs on people's smartphones, researchers say they were able to get a good idea of users' habits and lifestyles. 
 
 This included aspects such as diet, medications, hygiene and beauty products, general health, and places visited. 
 
 This approach could prove useful in a number of areas, including medical clinical trials, criminal profiling, airport screening, making sure patients are taking medications, and environmental exposure studies, said study senior author Pieter Dorrestein. 
 
 "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," said Dorrestein. He's a professor at the University of California, San Diego School of Medicine and School of Pharmacy and Pharmaceutical Sciences. 
 
 "So we thought -- what if we take advantage of left-behind skin chemistry to tell us what kind of lifestyle this person has?" Dorrestein said in a university news release. 
 
 Dorrestein and colleagues took swabs from four areas on the cellphones of 39 healthy adults. 
 
 "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," said study first author Amina Bouslimani. She's an assistant project scientist in Dorrestein's lab. 
 
 "This is the kind of information that could help an investigator narrow down the search for an object's owner," Bouslimani added. 
 
 Dorrestein said the study had limitations. His team's molecular analysis offered a general profile of a person's lifestyle, but could not make a distinct match, like a fingerprint. 
 
 The study was published Nov. 14 in the journal Proceedings of the National Academy of Sciences. 
 
 The researchers are continuing their study with an additional 80 people and samples from other personal objects such as wallets and keys. 
 
 More information 
 
 The American Academy of Family Physicians offers healthy living tips.
– Much like our keyboards, our smartphones are anything but clean. So researchers at UC San Diego decided to analyze the molecules on a handful of them and see what they could deduce about the phone's owners—and it turned out to be a whole lot. They swabbed four sections on the phones of 39 participants as well as eight spots on each volunteer's right hand, then conducted mass spectrometry on the samples to analyze the chemical traces, reports Live Science. Reporting in the journal Proceedings of the National Academy of Sciences, they say they compared the results to a huge database of molecules present in a wide range of medicines and commercial products, and were able to identify the usage of things we might want to keep quiet on, like anti-fungal medication and a hair loss treatment. "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 ... all kinds of things," says researcher Amina Bouslimani. In the case of the sunscreen and DEET, the researchers detected them even though it had been months since the phone owners applied them. So what to do with all this data? Well, "imagine a scenario where personal belongings such as pens, keys, phones, or handbags are found at an investigative site," the study abstract reads. Checking exposure to toxins or adherence to medicines are other possibilities. Health Day reports the researchers are already expanding the study to 80 more participants. (Beards, meanwhile, aren't as gross as we think.)