As previously observed in this space, water has a vital role in the defense against Covid-19, specifically through the cleansing function of regular hand washing.
But there’s another role that’s less obvious, and that’s the ability of water to help indicate the presence of the virus in communities where few if any people are showing up sick.
The water in this case isn’t just any water. It’s wastewater of the sewage sort..
In the Netherlands, the United Kingdom and the United States scientists are looking to public sewers to detect the presence of certain virus-related gene fragments that are carried along in urine and poop.
Wastewater surveillance is particularly important at a time when conventional testing for the coronavirus isn’t all that available and also where so many carriers have no symptoms.
Confirmation of that comes from Europe where, according to recent findings from the Netherlands- based KWR Water Research Institute, sewage testing picked up evidence of the virus when health authorities were aware of only 82 virus-sickened patients in the entire country. Here’s a report on KWR’s work.
Wastewater surveillance isn’t specific to individuals in the way that conventional tests are, but it has value nevertheless for putting out early warning signals that could prompt community leaders to develop precautionary strategies that call for such behaviors as social-distancing.
Early-alert capabilities might not seem all that important in communities that already know they’ve got a pandemic on their hands, but think of next autumn or later, after the surges in hospitals are over and the public’s mind has strayed, and the virus begins making a return. With so many victims showing no sign of illness for considerable periods of time, such early detection can be pretty important.
One source of expertise in wastewater surveillance is a start-up in Boston called Biobot Analytics. (The second part of the first name refers to the robotic tool that collects sewage samples.)
Biobot is the product of a teaming up of two MIT graduate students – one a biologist and the other an architect, both of them women. An early focus several years ago was opioid abuse; if sewage analysis could turn up drugs in a community, that information would be useful to community leaders wanting to know whether to allocate public health resources to the problem.
The use of sewers to detect worrisome happenings in a community isn’t all that easy. After all, wastewater isn’t necessarily just sewage; in many cases wastewater also contains stormwater, industrial waste and even some stuff that shouldn’t go down the toilet such as baby wipes.
But it remains that much of what goes into sewers comes out of humans and therefore has the potential to identify urban health problems. And that’s what makes mining the sewers for data all the more worth trying.