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Brisolara KF, Maal-Bared R, Sobsey MD, Reimers RS, Rubin A, Bastian RK, Gerba C, Smith JE, Bibby K, Kester G, Brown S. Assessing and managing SARS-CoV-2 occupational health risk to workers handling residuals and biosolids. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 774:145732. [PMID: 33611008 PMCID: PMC7869681 DOI: 10.1016/j.scitotenv.2021.145732] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 02/01/2021] [Accepted: 02/04/2021] [Indexed: 04/14/2023]
Abstract
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.
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Affiliation(s)
- Kari Fitzmorris Brisolara
- Louisiana State University Health Sciences Center, School of Public Health, 2020 Gravier Street, New Orleans, LA 70112, United States of America.
| | | | - Mark D Sobsey
- Gillings School of Global Public Health at the University of North Carolina, Chapel Hill, United States of America
| | - Robert S Reimers
- Tulane University School of Public Health and Tropical Medicine and Environmental Solutions, Pinnacle Waste Solutions, LLC Richmond, TX, United States of America
| | - Albert Rubin
- North Carolina State University, Department of Biological and Agricultural Engineering, Raleigh, NC, United States of America
| | - Robert K Bastian
- Retired - former USEPA, Washington, DC, United States of America
| | - Charles Gerba
- University of Arizona, Department of Environmental Science, Tucson, AZ, United States of America
| | - James E Smith
- Retired - former USEPA, Washington, DC, United States of America
| | - Kyle Bibby
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, IN, United States of America
| | - Greg Kester
- California Association of Sanitation Agencies, Sacramento, CA, United States of America
| | - Sally Brown
- University of Washington, Seattle, WA, United States of America
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Zhao L, Qi Y, Luzzatto-Fegiz P, Cui Y, Zhu Y. COVID-19: Effects of Environmental Conditions on the Propagation of Respiratory Droplets. NANO LETTERS 2020; 20:7744-7750. [PMID: 32909761 PMCID: PMC7496593 DOI: 10.1021/acs.nanolett.0c03331] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 09/09/2020] [Indexed: 05/20/2023]
Abstract
As coronavirus disease 2019 (COVID-19) continues to spread, a detailed understanding on the transmission mechanisms is of paramount importance. The disease transmits mainly through respiratory droplets and aerosol. Although models for the evaporation and trajectory of respiratory droplets have been developed, how the environment impacts the transmission of COVID-19 is still unclear. In this study, we investigate the propagation of respiratory droplets and aerosol particles generated by speech under a wide range of temperatures (0-40 °C) and relative humidity (0-92%) conditions. We show that droplets can travel three times farther in low-temperature and high-humidity environment, whereas the number of aerosol particles increases in high-temperature and low-humidity environments. The results also underscore the importance of proper ventilation, as droplets and aerosol spread significantly farther in airstreams. This study contributes to the understanding of the environmental impact on COVID-19 transmission.
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Affiliation(s)
- Lei Zhao
- Department of Mechanical Engineering,
University of California Santa
Barbara, Santa Barbara, California 93106,
United States
| | - Yuhang Qi
- Department of Mechanical Engineering,
University of California Santa
Barbara, Santa Barbara, California 93106,
United States
| | - Paolo Luzzatto-Fegiz
- Department of Mechanical Engineering,
University of California Santa
Barbara, Santa Barbara, California 93106,
United States
| | - Yi Cui
- Department of Materials Science and
Engineering, Stanford University, Stanford,
California 94305, United States
- Stanford Institute for Materials and
Energy Sciences, SLAC National Accelerator
Laboratory, Menlo Park, California 94025,
United States
| | - Yangying Zhu
- Department of Mechanical Engineering,
University of California Santa
Barbara, Santa Barbara, California 93106,
United States
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3
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Zhao L, Qi Y, Luzzatto-Fegiz P, Cui Y, Zhu Y. COVID-19: Effects of Environmental Conditions on the Propagation of Respiratory Droplets. NANO LETTERS 2020; 20:7744-7750. [PMID: 32909761 DOI: 10.1101/2020.05.24.20111963] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
As coronavirus disease 2019 (COVID-19) continues to spread, a detailed understanding on the transmission mechanisms is of paramount importance. The disease transmits mainly through respiratory droplets and aerosol. Although models for the evaporation and trajectory of respiratory droplets have been developed, how the environment impacts the transmission of COVID-19 is still unclear. In this study, we investigate the propagation of respiratory droplets and aerosol particles generated by speech under a wide range of temperatures (0-40 °C) and relative humidity (0-92%) conditions. We show that droplets can travel three times farther in low-temperature and high-humidity environment, whereas the number of aerosol particles increases in high-temperature and low-humidity environments. The results also underscore the importance of proper ventilation, as droplets and aerosol spread significantly farther in airstreams. This study contributes to the understanding of the environmental impact on COVID-19 transmission.
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Affiliation(s)
- Lei Zhao
- Department of Mechanical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Yuhang Qi
- Department of Mechanical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Paolo Luzzatto-Fegiz
- Department of Mechanical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
| | - Yi Cui
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Yangying Zhu
- Department of Mechanical Engineering, University of California Santa Barbara, Santa Barbara, California 93106, United States
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