Sewer systems are a window into the coronavirus pandemic

Photo by Beata Zawrzel / NurPhoto via Getty Images With limitations on COVID-19 testing making it hard to know how many people actually havethe disease, some public health experts are turning to the sewer systems for a clearer snapshot.“Sewage is a source of information on human health, and can really be transformed into a public health observatory,” says Newsha Ghaeli, president and co-founder of Biobot, a startup that analyzes wastewater.Wastewater-based disease monitoring is a re