Manish Arora studies a young boy’s tooth on his computer screen, searching for crucial details about the child’s past. The boy, 10 — we’ll call him Max — lives outside a poor community in Mexico City where lead exposure is a chronic problem. And it shows in the tooth. Max has been around lead from polluted air and water — and even food, because the metal leaches from lead-glazed pottery.
The image on the screen is essentially a color-coded map of the boy’s tooth. It shows Max had a spike in lead exposure just before birth, in the final months of fetal development. After birth, his exposure dropped off to a level common in the local population.
Blood tests can detect lead at any given moment, but they don’t reveal past exposures or time-stamp when they happened. Teeth, Arora has discovered, can do both — not just for lead, but for a growing number of other elements and chemicals, too.
Read the full story in Discover.