This Beer Knows Where You’ve Been

New research suggests that your visits to such places can be tracked by analyzing chemical traces in your hair. That’s because water molecules differ slightly in their isotope ratios depending on the minerals at their source. In a study published in the current issue of The Journal of Agricultural and Food Chemistry, researchers found that water samples from 33 cities across the United State could be reliably traced back to their origin based on their isotope ratios.

From the paper

The δ2H and δ18O values of a fluid input composed of beverages distributed on a large, regional scale may not necessarily mirror those of local tap water. The power of prediction using local tap water isotope ratios in models like that of Ehleringer et al. (1) would be confounded by the consumption of nonlocal beverages. On the other hand, some beverages (e.g., carbonated soft drinks, microbrew beer) likely use a more local distribution system. We expect the isotopic composition of a fluid input composed of beverages distributed on a small, local scale would generally mirror those of local tap water.

Which is why, to hide my whereabouts, I drink bottled water and imported beer. Stay thirsty, my friends.