The key is in the isotopes of hydrogen and oxygen, which vary in each area depending on the temperature of the clouds, the season of rainfall and the amount of water that evaporates from the soil and plants, as well as other local conditions. As scientists suggest today in the journal PNAS, the police could use this technique to investigate the alibi of an alleged criminal who claims not to have been in the region where the crime of which he is accused occurred. In addition, they propose that anthropologists and archaeologists analyze ancient hair samples to find out what migratory movements our ancestors followed.
And that's not all. The study of the isotopic levels of the hair could also be used to prevent diabetes . Because diabetics consume high amounts of water, the proportion of oxygen in their hair from both water and food should be different from that of non-diabetics, Cerlin says. The hair could also record the isotopic changes that occur when the disease worsens.
