TOXIC DUMP

YOUR BODY CONTAINS 206 BONES, 600 MUSCLES, 39 TRILLION MICROBES... AND DOZENS OF MAN-MADE CHEMICALS. AN EMERGING FIELD OF SCIENCE IS ASKING, WHAT'S REALLY IN US NOW-AND CAN WE STOP IT FROM KILLING US?

- DAVID FERRY

MICHAEL SNYDER, PH.D., IS WEARING FOUR SMARTWATCHES.

Inside his lab, the biggest on Stanford's perennially sunny campus, the director of the Center for Genomics and Personalized Medicine pulls up a seat and walks me through his very specific everyday carry.

For nearly a decade, Snyder has been trying to quantify human health. And although he has hundreds of volunteers in six different trials, he is his own best subject. His four different smartwatches spill out nine years' worth of heart-rate and skin-temperature data; a continuous glucose monitor graphs the effects that diet and exercise have on his blood sugar; an Oura ring tracks his sleep quality; and a black walkie-talkie-sized box he calls an exposometer "breathes" the same air as him and identifies all the airborne particles and chemicals he's exposed to in a day. (Not in the office today are his radiation monitor, a pulse oximeter, a camera that automatically takes photos of his environment every five minutes, and his smart cycling shorts, which were a bit of a bust.) Add all this to his semiannual MRIs, the microbiome and genome sequencing, and the hormone measurements and Snyder has more than 2 million gigabytes of his own health data stored. It is distinctly possible that Michael Snyder has more data on Michael Snyder than anyone has had on any human who has ever lived.

Snyder is a geneticist, renowned for helping to create revolutionary ways to analyze the genetic blueprint that makes up a life. For as long as humans have lived and died, we've been trying to explain why people get sick. Hippocrates blamed an imbalance of the biles, blood, and phlegm; medieval doctors chalked illness up to man's sinful ways. And for a generation now, since scientists first began to unravel our DNA, we've been primed to think that disease is written into our genes.