From the ACS Press Room Sewer Slime can Hang on to SARS-CoV-2 RNA from Wastewater “Accumulation of SARS-CoV‑2 RNA in of low and high COVID-19 incidence. Sewer Biofilms” To grow a simulated sewer slime, the researchers continuously pumped raw ACS ES&T Water wastewater into a cylindrical tank with reDuring the COVID-19 pandemic, monitoring movable pieces of polyvinyl chloride (PVC) the levels of SARS-CoV-2 RNA in inside. They conducted two 28-day experiwastewater entering treatment plants has ments, removing PVC plates every few days been one way that researchers have gauged to assess the biofilm’s composition. Then the the disease’s spread. But could the slimy mi- team used the method called reverse trancrobial communities that line most sewer scription quantitative polymerase chain reacpipes affect the viral RNA they encounter? In tion to measure the abundance of SARS-CoV a first-of-its-kind study, researchers report -2 RNA and pepper mottle virus (an indicator in ACS ES&T Water that sewer slime can of human feces) RNA in the untreated accumulate SARS-CoV-2 RNA, which could wastewater and the biofilms. decompose or slough off later, potentially imIn August and pacting the accuracy of wastewater epidemiSeptember ology studies. 2020, the levels of SARSAs the water and sludge from people’s homes CoV-2 RNA converge in sewers, some of the solids settle were too low out, and gooey microbial biofilms build up to accurately within the pipes. Previous researchers have measure in shown that RNA viruses, such as poliovirus, both the simuenteroviruses and noroviruses, can get trapped and collect in this slime. Yet whether lated sewer slime and the wastewater from the sticky material can also accumulate which it grew. These results align with a low SARS-CoV-2 viral particles or RNA from incidence of COVID-19 infections at that time, the researchers say. Then, during Nowastewater is unknown. Nicole Fahrenfeld vember and December 2020, although SARS and colleagues previously detected the vi-CoV-2’s presence in the wastewater itself rus’s RNA in sewer deposits from a universiwas still low, its RNA levels increased in the ty dormitory with a low number of COVIDslime. The amount of pepper mottle virus 19 cases, but the amount was too low to ac- RNA plateaued within the first week of curately assess. So, the team wanted to see if growth, indicating that the rise of SARS-CoV biofilms could incorporate SARS-CoV-2 Continued on Page 21 RNA from untreated wastewater during times February 2022
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