The countless chemicals and pathogens that you flush away end up in your nearest sewage treatment plant Abstract Aerial Art/Getty Images
WHAT鈥橲 the largest source of mass moving in and out of a city every day? You think, if it鈥檚 a port city, it must be boats聽鈥 or, you know, maybe if it鈥檚 a landlocked city, it鈥檚 trains or trucks or cars or planes. No, it鈥檚 water. It鈥檚 water. There鈥檚 so much more water moving in and out of a city any day than there is any kind of cargo. It鈥檚 basically pure water coming in. And then the water that leaves has some traces of almost every human activity that鈥檚 going on in the city.鈥
Once Eric Alm is in full flow, it is hard to stop聽him. But it isn鈥檛 hard to understand his enthusiasm. Alm, a biological engineer at the Massachusetts Institute of Technology, is one of a growing band of researchers turning their attention to the fluid coursing through our sewers. This waste water, as it is known, contains the whispered biochemical confessions of millions of people, and by listening to them, scientists can paint surprisingly detailed pictures of our health, wealth and environment, head off epidemics, track pandemics and even spot new 鈥渄esigner鈥 drugs before their effects show up in the population.
Water treatment plant Suriyapong Thongsawang/Getty Images
The field, called waste water-based epidemiology, not only has the potential to revolutionise public health but also transform our view of sewage from disgusting waste to something incredibly valuable. 鈥淵ou can think of the city as one…
