[ApolloRising]

This seems like a long shot suggestion but could you train a service dogs to detect the changes in the odor and to signal to the person for recording? Since the odor is very detectable even by humans then the dogs should have zero problems detecting it far sooner.

[Irene]

It should be possible, but might take a lot of effort. Smell-detecting dogs are trained from birth to 18 months and it takes another 6 months to specialize them on specific scent like diabetes. Small rodents could be trained too. In Harry Potter, Ron carried one in his breast pocket.