Assessing and managing SARS-CoV-2 occupational health risk to workers handling residuals and biosolids

Current wastewater worker guidance from the United States Environmental Protection Agency (USEPA) aligns with the Centers for Disease Control and Prevention (CDC) and the Occupational Safety and Health Administration (OSHA) recommendations and states that no additional specific protections against SARS-CoV-2, the virus that causes COVID-19 infections, are recommended for employees involved in wastewater management operations with residuals, sludge, and biosolids at water resource recovery facilities. The USEPA guidance references a document from 2002 that summarizes practices required for protection of workers handling class B biosolids to minimize exposure to pathogens including viruses. While there is no documented evidence that residuals or biosolids of any treatment level contain infectious SARS-CoV-2 or are a source of transmission of this current pandemic strain of coronavirus, this review summarizes and examines whether the provided federal guidance is sufficient to protect workers in view of currently available data on SARS-CoV-2 persistence and transmission. No currently available epidemiological data establishes a direct link between wastewater sludge or biosolids and risk of infection from the SARS-CoV-2. Despite shedding of the RNA of the virus in feces, there is no evidence supporting the presence or transmission of infectious SARS-CoV-2 through the wastewater system or in biosolids. In addition, this review presents previous epidemiologic data related to other non-enveloped viruses. Overall, the risk for exposure to SARS-CoV-2, or any pathogen, decreases with increasing treatment measures. As a result, the highest risk of exposure is related to spreading and handling untreated feces or stool, followed by untreated municipal sludge, the class B biosolids, while lowest risk is associated with spreading or handling Class A biosolids. This review reinforces federal recommendations and the importance of vigilance in applying occupational risk mitigation measures to protect public and occupational health.