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Indoor Air and COVID-19 Key References and Publications

This page lists some of the technical publications addressing the science related to transmission of SARS-CoV-2, the virus that causes COVID-19, through aerosols in indoor environments. This is an area of active research that is fast developing. Key publications about actions that can reduce the likelihood of this type of transmission are also listed. References will be updated periodically.

Multiple scientific journal articles have been published related to the issue of airborne transmission of SARS-CoV-2 through aerosols (also referred to as droplet nuclei). The lines of evidence include: 1) Reports of measurement of the virus in the air, including beyond the distance recommended for droplet transmission, 2) Physically-based models of emissions of virus-laden aerosols and their dynamics, 3) Evidence of airborne transmission for the closely-related coronaviruses that caused the SARS and MERS outbreaks 4) Epidemiological evidence suggestive of possible airborne transmission, though other routes cannot be excluded.

The relative importance of this route of SARS-CoV-2 transmission in comparison to others (close-contact, fomites) has not been established at this point. The weight of evidence supports the use of precautions against transmission of SARS-Co-V- 2 in indoor environments. Among these precautions, the effectiveness of engineering controls such as ventilation and air cleaning has been most frequently evaluated in the scientific literature.

Topics on this page: 

* research manuscripts that have not  been peer reviewed

** workshop reports, agency reports, and other sources that do not undergo a standard peer-review

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General

  • * Allen and Marr. (2020). Re-thinking the Potential for Airborne Transmission of SARS-CoV-2, Preprints, 2020050126.
  • Anderson et al. (2020). Consideration of the Aerosol Transmission for COVID‐19 and Public Health. Risk Analysis.
  • Domingo, J. L., Marquès, M., & Rovira, J. (2020). Influence of airborne transmission of SARS-CoV-2 on COVID-19 pandemic. A review. Environmental research, 188, 109861.
  • Jayaweera, M., Perera, H., Gunawardana, B., & Manatunge, J. (2020). Transmission of COVID-19 virus by droplets and aerosols: A critical review on the unresolved dichotomy. Environmental Research, 188, 109819.
  • Morawska, L., Tang, J. W., Bahnfleth, W., Bluyssen, P. M., Boerstra, A., Buonanno, G., ... & Haworth, C. (2020). How can airborne transmission of COVID-19 indoors be minimized? Environment international, 142, 105832.
  • Morawska, L., & Milton, D. K. (2020). It is time to address airborne transmission of COVID-19. Clin Infect Dis, 6, ciaa939.
  • ** Staudt, A., Saunders, J., Pavlin, J., Shelton-Davenport, M. (2020). National Academies of Sciences, Engineering, and Medicine, & Environmental Health Matters Initiative. Airborne Transmission of SARS-CoV-2, National Academies Press, ISBN-10: 0-309-68408-0.
  • Tellier, R., Li, Y., Cowling, B. J., & Tang, J. W. (2019). Recognition of aerosol transmission of infectious agents: a commentary. BMC infectious diseases, 19(1), 101.

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Reports of Measurements in Aerosols

  • Chia, P. Y., Coleman, K. K., Tan, Y. K., Ong, S. W. X., Gum, M., Lau, S. K., ... & Son, T. T. (2020). Detection of air and surface contamination by SARS-CoV-2 in hospital rooms of infected patients. Nature communications, 11(1), 1-7.
  • Fears, A. C., Klimstra, W. B., Duprex, P., Hartman, A., Weaver, S. C., Plante, K. S., ... & Nalca, A. (2020). Persistence of severe acute respiratory syndrome coronavirus 2 in aerosol suspensions. Emerging infectious diseases, 26(9), 2168.
  • Guo, Z. D., Wang, Z. Y., Zhang, S. F., Li, X., Li, L., Li, C., ... & Zhang, M. Y. (2020). Aerosol and surface distribution of severe acute respiratory syndrome coronavirus 2 in hospital wards, Wuhan, China, 2020. Emerg Infect Dis, 26(7), 10-3201.
  • Jin, T., Li, J., Yang, J., Li, J., Hong, F., Long, H., ... & Song, Q. (2020). SARS-CoV-2 presented in the air of an intensive care unit (ICU). Sustainable cities and society, 102446.
  • Lednicky, J. A., Lauzardo, M., Fan, Z. H., Jutla, A., Tilly, T. B., Gangwar, M., ... & Stephenson, C. J. (2020). Viable SARS-CoV-2 in the air of a hospital room with COVID-19 patients. International Journal of Infectious Diseases, 100, 476-482.
  • Ma, J., Qi, X., Chen, H., Li, X., Zhang, Z., Wang, H., ... & Grinshpun, S. A. (2020). Coronavirus disease 2019 patients in earlier stages exhaled millions of severe acute respiratory syndrome coronavirus 2 per hour.  Clinical Infectious Diseases, ciaa1283
  • Nissen, K., Krambrich, J., Akaberi, D., Hoffman, T., Ling, J., Lundkvist, Å., ... & Salaneck, E. (2020). Long-distance airborne dispersal of SARS-CoV-2 in COVID-19 wards. Scientific Reports, 10(1), 1-9.
  • Ong, S. W. X., Tan, Y. K., Chia, P. Y., Lee, T. H., Ng, O. T., Wong, M. S. Y., & Marimuthu, K. (2020). Air, surface environmental, and personal protective equipment contamination by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from a symptomatic patient. Jama, 323(16), 1610-1612.
  • Santarpia, J. L., Rivera, D. N., Herrera, V. L., Morwitzer, M. J., Creager, H. M., Santarpia, G. W., ... & Lawler, J. V. (2020). Aerosol and surface contamination of SARS-CoV-2 observed in quarantine and isolation care. Scientific reports, 10(1), 1-8.
  • Santarpia, J. L., Rivera, D. N., Herrera, V., Morwitzer, M. J., Creager, H., Santarpia, G. W., ... & Lawler, J. V. (2020). Transmission potential of SARS-CoV-2 in viral shedding observed at the University of Nebraska Medical Center. Scientific Reports, 10, 12732.
  • Van Doremalen, N., Bushmaker, T., Morris, D. H., Holbrook, M. G., Gamble, A., Williamson, B. N., ... & Lloyd-Smith, J. O. (2020). Aerosol and surface stability of SARS-CoV-2 as compared with SARS-CoV-1. New England Journal of Medicine, 382(16), 1564-1567.
  • Jie Zhou, Jonathan A Otter, James R Price, Cristina Cimpeanu, Danel Meno Garcia, James Kinross, Piers R Boshier, Sam Mason, Frances Bolt, Alison H Holmes, Wendy S Barclay. (2020). Investigating SARS-CoV-2 surface and air contamination in an acute healthcare setting during the peak of the COVID-19 pandemic in London. Clinical Infectious Diseases, ciaa905.

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Physically-based Modeling of Aerosol Dynamics

  • Buonanno, G., Stabile, L., & Morawska, L. (2020). Estimation of airborne viral emission: quanta emission rate of SARS-CoV-2 for infection risk assessment. Environment International, 105794.
  • Johnson, G. R., Morawska, L., Ristovski, Z. D., Hargreaves, M., Mengersen, K., Chao, C. Y. H., ... & Corbett, S. (2011). Modality of human expired aerosol size distributions. Journal of Aerosol Science, 42(12), 839-851.
  • Liu, L., Li, Y., Nielsen, P. V., Wei, J., & Jensen, R. L. (2017). Short‐range airborne transmission of expiratory droplets between two people. Indoor Air, 27(2), 452-462.
  • Qian, H., & Zheng, X. (2018). Ventilation control for airborne transmission of human exhaled bio-aerosols in buildings. Journal of thoracic disease, 10(Suppl 19), S2295.
  • Riediker, M., & Tsai, D. H. (2020). Estimation of Viral Aerosol Emissions From Simulated Individuals With Asymptomatic to Moderate Coronavirus Disease 2019. JAMA Netw Open, 3(7):e2013807.
  • Stadnytskyi, V., Bax, C. E., Bax, A., & Anfinrud, P. (2020). The airborne lifetime of small speech droplets and their potential importance in SARS-CoV-2 transmission. Proceedings of the National Academy of Sciences, 117(22), 11875-11877.

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Evidence of Airborne Transmission for SARS and MERS

  • Xiao, S., Li, Y., Sung, M., Wei, J., & Yang, Z. (2018). A study of the probable transmission routes of MERS‐CoV during the first hospital outbreak in the Republic of Korea. Indoor Air, 28(1), 51-63.
  • Yu, I. T., Li, Y., Wong, T. W., Tam, W., Chan, A. T., Lee, J. H., ... & Ho, T. (2004). Evidence of airborne transmission of the severe acute respiratory syndrome virus. New England Journal of Medicine, 350(17), 1731-1739.

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Epidemiological Evidence Suggestive of Transmission Through Aerosol

  • Brlek, A., Vidovič, Š., Vuzem, S., Turk, K., & Simonović, Z. (2020). Possible indirect transmission of COVID-19 at a squash court, Slovenia, March 2020: case report. Epidemiology & Infection, 148.
  • ** Hamner, L. (2020). High SARS-CoV-2 attack rate following exposure at a choir practice—Skagit County, Washington, March 2020. MMWR. Morbidity and Mortality Weekly Report, 69.
  • * Li, Y., Qian, H., Hang, J., Chen, X., Hong, L., Liang, P., ... & Kang, M. (2020). Evidence for probable aerosol transmission of SARS-CoV-2 in a poorly ventilated restaurant. medRxiv. 
  • Miller, S. L., Nazaroff, W. W., Jimenez, J. L., Boerstra, A., Buonanno, G., Dancer, S. J., ... & Noakes, C. (2020). Transmission of SARS‐CoV‐2 by inhalation of respiratory aerosol in the Skagit Valley Chorale superspreading event. Indoor Air., 00: 1– 10.
  • Park, S. Y., Kim, Y. M., Yi, S., Lee, S., Na, B. J., Kim, C. B., ... & Huh, I. S. (2020). Coronavirus Disease Outbreak in Call Center, South Korea. Emerg. infect. dis., 26(8), 1666-1670.
  • Shen, Y., Li, C., Dong, H., Wang, Z., Martinez, L., Sun, Z., ... & Wang, F. (2020). Community outbreak investigation of SARS-CoV-2 transmission among bus riders in eastern China. JAMA Internal Medicine, Published online September 01, 2020. 

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Effect of Indoor Environmental Conditions

  • Biryukov, J., Boydston, J. A., Dunning, R. A., Yeager, J. J., Wood, S., Reese, A. L., ... & Phillips, A. (2020). Increasing temperature and relative humidity accelerates inactivation of SARS-CoV-2 on surfaces. MSphere, 5(4).
  • Chin, A., Chu, J., Perera, M., Hui, K., Yen, H. L., Chan, M., ... & Poon, L. (2020). Stability of SARS-CoV-2 in different environmental conditions. The Lancet Microbe, 2020; 1: e10.
  • Eslami, H., & Jalili, M. (2020). The role of environmental factors to transmission of SARS-CoV-2 (COVID-19). AMB Express, 10(1), 1-8.
  • * Morris, D. H., Yinda, K. C. H., Gamble, A., Rossine, F. W., Huang, Q., Bushmaker, T., ... & Marr, L. C. (2020). The effect of temperature and humidity on the stability of SARS-CoV-2 and other enveloped viruses. bioRxiv.
  • Thatcher, T. L., Lai, A. C., Moreno-Jackson, R., Sextro, R. G., & Nazaroff, W. W. (2002). Effects of room furnishings and air speed on particle deposition rates indoors. Atmospheric environment, 36(11), 1811-1819.
  • * Wang, J., Tang, K., Feng, K., & Lv, W. (2020). High temperature and high humidity reduce the transmission of COVID-19. Available at SSRN 3551767.

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​Ventilation and Air Cleaning

  • Christopherson, D. A., Yao, W. C., Lu, M., Vijayakumar, R., & Sedaghat, A. R. (2020). High-efficiency particulate air filters in the era of COVID-19: Function and efficacy. Otolaryngology–Head and Neck Surgery, 0194599820941838.
  • Dai, H., & Zhao, B. (2020, August). Association of the infection probability of COVID-19 with ventilation rates in confined spaces. In Building Simulation, 13, 1321–1327.
  • Kowalski, W. J., & Bahnfleth, W. P. (2002). MERV filter models for aerobiological applications. Air Media, Summer, 1.
  • Li, Y., Leung, G. M., Tang, J. W., Yang, X., Chao, C. Y., Lin, J. Z., ... & Sleigh, A. C. (2007). Role of ventilation in airborne transmission of infectious agents in the built environment-a multidisciplinary systematic review. Indoor air, 17(1), 2-18.
  • Morawska, L., Tang, J. W., Bahnfleth, W., Bluyssen, P. M., Boerstra, A., Buonanno, G., ... & Haworth, C. (2020). How can airborne transmission of COVID-19 indoors be minimised? Environment international, 142, 105832.
  • Mousavi, E. S., Kananizadeh, N., Martinello, R. A., & Sherman, J. D. (2020). COVID-19 Outbreak and hospital air quality: A systematic review of evidence on air filtration and recirculation. Environmental Science & Technology.
  • Schoen, L. J. (2020). Guidance for building operations during the COVID-19 pandemic. ASHRAE Journal, 72-74.
  • Zhao, B., Liu, Y., & Chen, C. (2020). Air purifiers: A supplementary measure to remove airborne SARS-CoV-2. Building and Environment, 177, 106918.

Other

  • Anfinrud, P., Stadnytskyi, V., Bax, C. E., & Bax, A. (2020). Visualizing speech-generated oral fluid droplets with laser light scattering. New England Journal of Medicine, 382, 2061-2063.
  • Arslan, M., Xu, B., & El-Din, M. G. (2020). Transmission of SARS-CoV-2 via fecal-oral and aerosols–borne routes: Environmental dynamics and implications for wastewater management in underprivileged societies. Science of the Total Environment, 743, 140709.
  • Augenbraun, B. L., Lasner, Z. D., Mitra, D., Prabhu, S., Raval, S., Sawaoka, H., & Doyle, J. M. (2020). Assessment and mitigation of aerosol airborne SARS-CoV-2 transmission in laboratory and office environments. Journal of Occupational and Environmental Hygiene, 1-10.
  • Bourouiba, L. (2020). Turbulent gas clouds and respiratory pathogen emissions: potential implications for reducing transmission of COVID-19. Jama, 323(18), 1837-1838.
  • Buonanno, G., Morawska, L., & Stabile, L. (2020). Quantitative assessment of the risk of airborne transmission of SARS-CoV-2 infection: prospective and retrospective applications. Environment International, 145, 106112.
  • Colaneri, M., Seminari, E., Novati, S., Asperges, E., Biscarini, S., Piralla, A., ... & Mondelli, M. U. (2020). SARS-CoV-2 RNA contamination of inanimate surfaces and virus viability in a health care emergency unit. Clinical Microbiology and Infection, 26(8), 1094e1-1094e5.
  • * Fears, A. C., Klimstra, W. B., Duprex, P., Hartman, A., Weaver, S. C., Plante, K. C., ... & Nalca, A. (2020). Comparative dynamic aerosol efficiencies of three emergent coronaviruses and the unusual persistence of SARS-CoV-2 in aerosol suspensions. medRxiv. preprint DOI.
  • Freedman, D. O., & Wilder-Smith, A. (2020). In-flight Transmission of SARS-CoV-2: a review of the attack rates and available data on the efficacy of face masks. Journal of Travel Medicine, taaa178. Advance online publication.
  • Furukawa, N. W., Brooks, J. T., & Sobel, J. (2020). Evidence supporting transmission of severe acute respiratory syndrome coronavirus 2 while presymptomatic or asymptomatic. Emerging infectious diseases, 26(7).
  • He, X., Lau, E. H., Wu, P., Deng, X., Wang, J., Hao, X., ... & Mo, X. (2020). Temporal dynamics in viral shedding and transmissibility of COVID-19. Nature medicine, 26(5), 672-675.
  •  Lelieveld, J., Helleis, F., Borrmann, S., Cheng, Y., Drewnick, F., Haug, G., ... & Pöschl, U. (2020). Model Calculations of Aerosol Transmission and Infection Risk of COVID-19 in Indoor Environments. International Journal of Environmental Research and Public Health, 17(21), 8114.
  • Lu, J., Gu, J., Li, K., Xu, C., Su, W., Lai, Z., ... & Yang, Z. (2020). COVID-19 outbreak associated with air conditioning in restaurant, Guangzhou, China, 2020. Emerging infectious diseases, 26(7), 1628.
  • Milton, D. K., Fabian, M. P., Cowling, B. J., Grantham, M. L., & McDevitt, J. J. (2013). Influenza virus aerosols in human exhaled breath: particle size, culturability, and effect of surgical masks. PLoS Pathog, 9(3), e1003205.
  • Morawska, L. J. G. R., Johnson, G. R., Ristovski, Z. D., Hargreaves, M., Mengersen, K., Corbett, S., ... & Katoshevski, D. (2009). Size distribution and sites of origin of droplets expelled from the human respiratory tract during expiratory activities. Journal of Aerosol Science, 40(3), 256-269.
  • Mutuku, J. K., Hou, W. C., & Chen, W. H. (2020). An overview of experiments and numerical simulations on airflow and aerosols deposition in human airways and the role of bioaerosol motion in COVID-19 transmission. Aerosol and Air Quality Research, 20(6), 1172-1196.
  •  * Nishiura, H., Oshitani, H., Kobayashi, T., Saito, T., Sunagawa, T., Matsui, T., ... & Suzuki, M. (2020). Closed environments facilitate secondary transmission of coronavirus disease 2019 (COVID-19). MedRxiv preprint DOI.
  • Prather, K. A., Wang, C. C., & Schooley, R. T. (2020). Reducing transmission of SARS-CoV-2. Science.
  • Richard, M., Kok, A., de Meulder, D., Bestebroer, T. M., Lamers, M. M., Okba, N. M., ... & Fouchier, R. A. (2020). SARS-CoV-2 is transmitted via contact and via the air between ferrets, Nature Communications, 11, 3496.
  • Scheuch, G. (2020). Breathing is enough: For the spread of influenza virus and SARS-CoV-2 by breathing only. Journal of aerosol medicine and pulmonary drug delivery, 33(4), 230-234.
  • Shi, J., Wen, Z., Zhong, G., Yang, H., Wang, C., Huang, B., ... & Zhao, Y. (2020). Susceptibility of ferrets, cats, dogs, and other domesticated animals to SARS–coronavirus 2. Science, 368(6494), 1016-1020.
  • Somsen, G. A., van Rijn, C., Kooij, S., Bem, R. A., & Bonn, D. (2020). Small droplet aerosols in poorly ventilated spaces and SARS-CoV-2 transmission. The Lancet. Respiratory Medicine, 8(7), 658–659.
  • Sze To, G. N., & Chao, C. Y. H. (2010). Review and comparison between the Wells–Riley and dose‐response approaches to risk assessment of infectious respiratory diseases. Indoor air, 20(1), 2-16.
  • Wang, B., Zhang, A., Sun, J. L., Liu, H., Hu, J., & Xu, L. X. (2005). Study of SARS transmission via liquid droplets in air. J. Biomech. Eng., 127(1), 32-38.
  • Wang, J., & Du, G. (2020). COVID-19 may transmit through aerosol. Irish Journal of Medical Science (1971-), 1-2.
  • Wu, S., Wang, Y., Jin, X., Tian, J., Liu, J., & Mao, Y. (2020). Environmental contamination by SARS-CoV-2 in a designated hospital for coronavirus disease 2019. American Journal of Infection Control, 48(8), 910-914.
  • Ye, G., Lin, H., Chen, L., Wang, S., Zeng, Z., Wang, W., ... & Yang, Z. (2020). Environmental contamination of SARS-CoV-2 in healthcare premises. Journal of Infection, 81(2), e1-e5.

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