He discussed many real applications of his work, including how mass spectrometry can be used to help determine if a cheque has been forged by analysing ink on paper fibres, how isotope ratios can be used to determine the origins of soil and wine, and whether environmental contamination, for example mercury in the Great Barrier reef, occurred recently or hundreds of years ago.
He explained how he had been growing his hair as part of an experiment to show that chemicals trapped in hair can indicate which part of the world a person has been to. Everyday chemicals, including those in soap, drinking water and diet can be used to place the whereabouts of a person, down to the number of days they have spent in a particular location. Analysis of Stewart's hair a few years ago accurately showed that he had travelled from Australia, to Norway for 10 days, then onto New Orleans for 5 days, Prague for 10 days and then finally back to Australia. This sort of technology could be used to help identify corpses after natural disasters as well tracking the movement of people around the world.
He described how he has only recently shaved his hair off after growing it for ten years. Now people from all over the world want to use to experiment with it, including a group that want to blow it up!
|Zoe and Naomi with the Stewart (minus his hair!)|