Sneezes and coughs are aerosols, and in full sunlight, in pretty cool conditions, even in dry climates (it was 80-90 degrees here yesterday, and over 90 today) sunlight kills COVID-19 in 1.5 minutes. Public drinking fountains have been kept sanitary by full sunlight for centuries, because sunlight, with enough exposure, kills EVERYTHING.
After 9/11 a govt lab was set up at DHS, the National Biodefense Analysis and Countermeasures Center lab (say that three times fast), to test for biological weapons. They've done some preliminary testing on COVID-19. It's unclassified - but for official use only. SMH. WTF!?! So I want to emphasis the great officialness of this use!
I should point out that contrary to my last post's speculation, HIGHER humidity, not lower, kills COVID-19 faster, but nothing like sunlight's 3 minutes.
Anyway, here's the link to the PDF file. Sunlight kills COVID-19 to undetectable levels in ~ 3 minutes in full sunlight. Here in the high desert we're beyond "Full Sunlight", but the study includes definitions for Full, Half, and Quarter sun, so you don't have to guess without some guidance.
AFAICT, based on Weather Underground's real-time reporting of solar energy during the day, we have ~ 125% of sea level sunlight here at 3,000ft, although irradiance depends heavily on the exact wavelength of light. Shorter, higher energy wavelengths are not screened out as well by Earth's atmosphere as longer wavelengths are.
Simultaneously taken measurements of solar irradiance with high resolution spectrometers at Garmisch-Partenkirchen, Germany (730 m a.s.l.) and Wank (1730 m a.s.l.), horizontally separated by 5 km, show a clear wavelength dependence of the altitude effect of the global irradiance: 9% per 1000 m at 370 nm increasing to 11% per 1000 m at 320 nm and 24% per 1000 m at 300 nm. The altitude effect of direct irradiance is considerably higher than that of global irradiance at all measured wavelengths.
Heat & Humidity reduce 18 hrs of required kill time indoors substantially - to less than 1hr at 60% RH and 95 degrees Fahrenheit. Note that some airline cabins are sterilized by UV-C lamps, a wavelength screened almost 100% by our atmosphere. UV-C kills almost immediately as air is channeled past a long irradiating tube, so air travel in that case should be safe WHILE IN THE AIRCRAFT.
Of interest to me, age plays a huge role in mortality, doubling twice between 60 and 89.
Worth mentioning at this point that I tried in vain a couple of days ago to ride while covering my mouth with my Turtle Fur balaclava, my lightest one, and was gasping for breath in 2 miles while sweating profusely in 80 degree weather. Knowing that sunlight kills COVID-19 in a few minutes, I will ride on sunny days with no face covering in remote places, bringing along a neck gaiter to cover my face if indoors.
Please do read the full report in the linked PDF file. It's quite helpful and short.
Stay safe, but get some!
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