In their quest to detect early outbreaks, virus hunters are sampling environmental DNA in water, dirt, and air. It all started when Christopher Mason’s 3-year-old daughter licked a subway pole.Like any parent, he was horrified, but also keenly curious: What types of microbes might be clinging to a metal pipe gripped by countless commuters every day?
Mason, a geneticist at Weill Cornell Medicine, soon became obsessed with that question. His toddler’s gross interlude inspired him to embark on a journey to unveil the world of bacteria, fungi, and viruses co-mingling with more than 8 million people in New York City’s urban jungle.
In 2013, he launched a project that began dispatching a small army of students shouldering backpacks crammed with latex gloves, vials, and sterile Q-tips. They sampled turnstiles, benches, and kiosks at every open metro stop in the city. It was an expedition into a largely unexplored terrain, like Mars or a deep-sea canyon, brimming with lifeforms both familiar and unknown.