Guidance from doctors in Germany includes the following effects of wearing a face covering on transmission. This is based on two people in close conversation, with one on them carrying the virus.
1. Neither wear a face covering: Chance of transmission ~90%
2. Only the uninfected person wears a face covering: Chance of transmission ~30%.
3. Only the infected person wears a face covering: Chance of transmission ~5%.
4. Both wear a face covering: Chance of transmission ~1.5%
A graphic is available HERE.
We can offer some guidance on safe use of churches allowing from covid-19 variants of our YouTube Channel 'Stewarding precious Earth'. This includes guidance on ventilation.,on covid safety and on use of carbon dioxide meters; a procedure for using a meter and improving air quality is provided on this page.
Updated September 29, 2021.