Researchers: COVID-19 In Sewage Helps More Than It Hurts

Speaker 1: 00:00 Sewage is being tested in San Diego and other places as a way to understand how widespread COVID-19 infections are in the region, KPBS environment, reporter Eric Anderson says that raises a question about whether the presence of the virus in sewage is a public health risk. Speaker 2: 00:18 UC San Diego has already used the waste stream to identify local COVID-19 outbreaks. Each dorm has its own sewage system can pray. There is an atmospheric chemist at the school who's working with school officials to develop early COVID warning systems. Sampling air is one way sampling sewage for the virus is another. Speaker 1: 00:37 Since we can't test everybody all the time, that's a way that we'll we'll do that very frequently. And so if it starts to go up in the sewage of a particular dorm, then we can figure out how to test and isolate the students. Speaker 2: 00:51 The sewage testing has already led to two people who were Corona virus positive, but not showing symptoms. The virus was found in sewage coming from several campus buildings, the same receptors that take into the gastrointestinal tract. They're there as well. So the virus grows in the GI tract and is shed into the stool. Richard Schooley is a distinguished professor of medicine at UCLA. He says, researchers look for RNA parts of the virus that persist in the waste stream. The presence of that genetic material can serve as an early warning. Beacon of an infectious outbreak analysts are not looking for active viruses, capable of infecting another host, and it's not clear that they would find them to be infectious. The virus has to be present as a full viral particle, surrounded a very delicate basically bubble of the church. And so the kinds of things to get done in sewage treatment plants are just the kinds of things as far as doesn't like, but in untreated sewage, the virus could potentially survive school. Speaker 2: 01:53 He says high concentrations of airborne particles of the SARS COVID virus got into a Hong Kong apartment complex back in 2003, it came from a pool of sewage stored beneath the building, the particle spread through plumbing in this well-documented case, and then to residence, this was not treated sewage water. The apartment complex was called the, uh, Moya garden complex. And, uh, the best evidence we have is that the virus heiress loss from this untreated sewage pool, uh, and air currents was able to spread through the air. But the virus is unlikely to survive in the San Diego waste stream Speaker 1: 02:33 Adapted very well, um, to survive outside of the host. However, some may possibly get through better, still viable, meaning contagious. Sure. Speaker 2: 02:42 Lawrence is the city of San Diego's director of public utilities. She says wastewater moves through the city systems to a treatment plan where a lot of things happen that the virus doesn't like Speaker 1: 02:54 It says what we're very careful about is to make sure it's not just one layer, but there's multiple layers of treatment. So if for any bizarre reasons something happened in one of them, there's still additional treatment plant processes that will take care of it. Speaker 2: 03:10 Lawrence says recycling wastewater involves even more treatment. And when the city's pure water project is up and running, wastewater will be turned into distilled pathogen, free water, but not all wastewater gets treated before it enters the environment. San Diego has endured billions of gallons of sewage tainted cross border flows. Since COVID-19 hit the region in spring and UC San Diego's Richard Schooley says there is reason for concern. There's potentially public health risk for a lot of pathogens and untreated sewage water, whether it's on water river or from the Mississippi river school, he says sunlight and dilution can go a long way toward reducing the risk of a virus like COVID-19. But he says treating the waste water is the best step to protecting public safety. Eric Anderson KPBS news.