Nature: “…Converging lines of evidence indicate that SARS-CoV-2, the coronavirus responsible for the COVID-19 pandemic, can pass from person to person in tiny droplets called aerosols that waft through the air and accumulate over time. After months of debate about whether people can transmit the virus through exhaled air, there is growing concern among scientists about this transmission route. This week, Lidia Morawska, aerosol scientist, who works at the Queensland University of Technology and aerosol scientist Donald Milton at the University of Maryland, College Park, supported by an international group of 237 other clinicians, infectious-disease physicians, epidemiologists, engineers and aerosol scientists, published a commentary in the journal Clinical Infectious Diseases that urges the medical community and public-health authorities to acknowledge the potential for airborne transmission. They also call for preventive measures to reduce this type of risk…A few studies, however, have successfully measured the viability of aerosol-borne virus particles. A team at the US Department of Homeland Security Science & Technology Directorate in Washington DC found that environmental conditions play a big part in how long virus particles in aerosols remain viable. SARS-CoV-2 in mock saliva aerosols lost 90% of its viability in 6 minutes of exposure to summer sunlight, compared with 125 minutes in darkness. This study suggests that indoor environments might be especially risky, because they lack ultraviolet light and because the virus can become more concentrated than it would in outdoor spaces…”