Welcome to brain Stuff, a production of I Heart Radio, Hey brain Stuff, Lauren Volga bam here. It's comforting to assume that once you flush the toilet, the contents are out of sight, out of mind. But what most people probably don't realize is that the stuff we flush away can tell us a lot about the health of ourselves and our community. And that stuff has proven to be a valuable resource in monitoring the coronavirus pandemic in communities
around the world. It's called wastewater monitoring or wastewater based epidemiology, and since early in the pandemic, a growing number of researchers across the United States have been testing samples of untreated wastewater for coronavirus. They've found levels of the virus and sewage plants given early warning about levels of positive COVID nineteen tests in the communities they serve for. The article of this episode is based on how Stuff Work.
Spoke with Devada S. Smith, PhD. And so see It, professor of microbiology at Texas and M University, San Antonio. She said, I've been teaching for a long time all the interesting things you can learn from toilets. She runs the Smith Lab, where she and her undergraduate team study comparative microbial genomics and evolution. She's also the daughter of a plumber, and she's focused much of her research into
the wealth of information that goes into toilets. Our poop is made up primarily of water, but the remaining er so is a cocktail of undigested food, residue, fats, salts, mucus, and human pathogens like bacteria and viruses. If you're infected with the coronavirus that causes the COVID nineteen infection, then it'll show up in your excrement too. Everything that washes down the drains of our toilets, sinks, tubs, and street gutters travels from miles through our community sanitary sewer system
into bigger and bigger sewer pipes. This ver of communal sewage flows into a local wastewater treatment facility, where it's ultimately pasteurized and the harmful material is removed. Regularly monitoring wastewater samples over the course of time enables researchers to
establish a trend analysis. These analyzes have detected spikes and new variants days even weeks before COVID nineteen testing via nasal swabs could and since all cities and towns have their own sewage plants, researchers can pinpoint where spikes will be and whether a new variant is emerging as one of concern, Smith explained, imagine if you had two weeks lead time and a potential outbreak situation at a dorm or a hospital or other facility, you could potentially target
your interventions and maybe reduce the impact of that outbreak. For example, communities could ramp up messaging to alert the public to practice masking, social distancing, and other measures to limit the spread of the virus, as well as encouraged testing in self isolation for those who test positive. Surveillance also gives researchers a better understanding of how the virus mutates and how those variants react to vaccines, factors that
are vital to keeping the public safe. Smith said, we need to understand the virus because we don't know where it's going next. Public health officials have learned a lot about COVID nineteen by tracking the number of positive tests by county, state, country, and more. But testing has its limitations For starters, it requires people to actually get tested. Many do if they become exposed to the virus, have developed symptoms, or are required to do so for their jobs.
But not everyone in a community chooses to get tested, either because they don't have health insurance, have no access to tests, aren't showing symptoms, or simply don't want to get tested. Smith said, if you don't get tested, then we don't have any data from you. But everybody poops, everybody how to go to the bathroom. So with wastewater testing, we have the data on potentially every single person in
a system. Of course, not all municipalities are testing their wastewater, but many are voluntarily participating thanks to grants and other sources of funding, including the CARES Act. In September of the Centers for Disease Control and Prevention or CDC, launched the National Wastewater Surveillance Systems or NWSS to coordinate and build on the country's capacity to track the novel coronavirus
in samples collected at wastewater plants across the country. As part of that project, the agency recently unveiled a new CDC COVID Data Tracker, where all the data on wastewater testing is centralized onto one dashboard for the public to view. Several municipalities have created their own dashboards to share their data and trend analyzes. The CDC expects participation in the program to grow as health departments and public health laboratory
further build their capacity to coordinate wastewater surveillance. However, it's still a developing field and there are limitations. Among them, treatment plants don't capture homes on septic systems or communities served by decentralized systems that treat their own waste, such as hospitals or universities. However, many colleges and universities are collecting their own data, including Emory University, the University of Miami, and the University of Buffalo, just to name a few.
And while concentrations of the virus and wastewater sampling can indicate just how impacted a community is, it can't tell the exact numbers of those infected. But having all the data on one page, literally and figuratively, can offer a better picture of how the virus is impacting our country. Of course, wastewater epidemiology is not new, We've talked about it on the show before, and virus tracking vias sewage has been going on for over fifty years. Smith said, Oh,
wastewater is very sexy right now. It's all over the news. But here's the thing. People have been using wastewater surveillance for years to look for things like polio. For example, polio has been eradicated in nearly all countries thanks to the polio vaccine, but transmission is still ongoing in three
countries where vaccines lag Nigeria, Afghanistan, and Pakistan. Rather than relying on reported cases of acute flaccid paralysis, a probable cause of polio, researchers have been looking in sewage to detect poliovirus shed in the feces of non paralyzed people
infected with polio. Wastewater surveillance has also been used to detect other viruses such as hepatitis B and norovirus, and Smith says she's currently working to refine testing techniques to better monitor sewage plants for the flu a. Smith referenced a local sanitation utility employer who recently said to her, it's only wastewater if you don't use it. M Today's episode is based on the article hoop slutes why researchers are tracking coronavirus in Wastewater on how stuff works dot Com,
written by Jennifer Walker. Journey brain Stuff is production of by Heart Radio in partnership with how stuff Works dot Com and is produced by Tyler Klang and Ramsey Yamp. Four more podcasts from my heart Radio, visit the I heart Radio app, Apple Podcasts, or wherever you listen to your favorite shows.