Disclaimer: The following is information often based on one or a few science journal publications. It is presented here for your review. You will need to consult the original science journal article for details end explanations.
Droplets vs airborne transmission in COVID-19 (WHO March 2020)
Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1
Evidence suggests, according to scientists, that people may be spreading the virus without knowing.” Most secondary cases of virus transmission appear to be occurring in community settings rather than healthcare settings,” the study said. “The scientists found that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was detectable in aerosols for up to three hours, up to 24 hours on cardboard and up to two to three days on plastic and stainless steel,” the National Institutes of Health said. The approximate half-life of viable virus ranged from 5-6 hours on plastics and stainless steel. This data likely simulates worst case scenarios. And, how exposure to sunlight, heat, or cold, can affect Covid 19 survival times is not known yet.
Survival of Severe Acute Respiratory Syndrome Coronavirus
Survival of Influenza A (H1N1) on Materials Found in Households: Implications for Infection Control
In contrast a study from 2011 found the H1N1 flu remained infectious for up to 48h after landing on non-porous surfaces such as stainless steel or plastic, however, most virus particles were inactivated after nine hours. Both cold and flu viruses survive for much shorter times on porous surfaces such as cloth, paper, or tissue, with very little infectious virus remaining after four hours.
Warmer temperatures inactivate virus faster
It appears that the coronavirus is inactivated at warmer/hotter temperatures than cold. This may be the reason flu viruses are seasonal and taper off in the summer (warmer) months.
Dryer environments inactivate virus faster
It appears that the coronavirus is inactivated at lower relative humidities and on surfaces that may dry faster. Keep in mind if this were completely true, then we should see less influenza cases in dry climate areas of the country and I believe that is not the case.
Physical interventions to interrupt or reduce the spread of respiratory viruses
It appears that frequent hand washing, wearing a mask, gloves and gown COMBINED is very effective in reducing the spread of respiratory viruses.
| Intervention | Effectiveness (%) |
| Freq. hand washing (≥ 10 x day) | 55 |
| Wearing face mask | 68 |
| Wearing N95 face mask | 91 |
| Wearing gloves | 57 |
| Wearing gown | 77 |
| Hand washing, mask, gloves, and gown | 91 |
Stability and inactivation of SARS Coronavirus
Thermal inactivation of SARS-CoV at 56 and 60C is highly effective; however, in the presence of protein (20%), infectivity was only reduced by less than 2log10 at 56C after 30 min (and also after 60 min).
Human Coronaviruses: Insights into Environmental Resistance and Its Influence on the Development of New Antiseptic Strategies
