These past several weeks I've progressed in my understanding of the hideous coronavirus (CV) and developed a protocol for Carol and me to follow. We're in the "over 70 generation" and especially vulnerable. A key part of this protocol is wearing masks -- the right kind of masks. Here's what I've learned.
The term "LIfe Expectancy" is a misnomer here because CV is not a living thing. It doesn't die, it breaks down i.e. disintegrates into harmless particles. How stable is the CV particle before it breakdowns all depends on the surface it's in contact with. This topic is still not fully understood.
Here is a March 17, 2020 National Institute of Health (NIH) news release:
"The scientists found that severe respiratory syndrome coronavirus 2 (SARS-CoV)-2) was detectable in aerosols for up to three hours, up to four hours on copper, up to 24 hours on cardboard and up to two to three days on plastic and stainless steel.
Here's one graph that shows how the amount of active virus particle decreases on different surfaces with time, i.e. finally reaching a low, safe, level. For the KN95 and N95 nonwoven mask materials the highly active CV amount decreases to a very low level in 4 hours. Playing it safe think at least 8 hours.