Can UV light fight coronavirus?

March 13, 2020

Michael Zajic’s well-meaning letter March 3 about the use of ultraviolet light to fight the Corona virus had merit, but was incomplete in terms of many critical details and other issues. So, before you go out and buy or turn on, please read on.
In terms of killing a living bacterial or microbial pathogen, or inactivating a pathogenic virus particle (a non-living but infectious entity), any killing agent does not kill instantly.

The only practicable way you can measure this killing is by measuring the numbers in a population of infectious agent entities both before and after exposure to the killing agent. And - in short - the way it works is the agent kills some fraction of the total number of entities after an exposure for some number of minutes. After exposure for another period of the same minutes, another fraction of the remaining viable entities is killed. And so on. It is a complex process.

Thus, if, for example, water is contaminated with a pathogen, then boiling for 20 minutes may be much much more effective than boiling for two minutes, depending on the details.

The use of ultraviolet light is not without other issues. UV produces ozone and some people will find the smell pleasant, but there are reports of ozone being an irritant that causes its own pulmonary medical symptoms. A second detail is that the UV light which is tearing up virus DNA is also tearing up the DNA in your skin cells, thus increasing the probability of skin cancer, so that requires a consideration. UV light also causes a number of other complex photochemical reactions, and interested readers are referred to the internet for more details.

Most people forget and most media reports don’t mention that the flu is currently a bigger problem than the coronavirus. This is because the flu just does not get as much press because it is not news. Also, very recent reports are saying that about half of all people who got the corona illness have already recovered through their own immune response and are thus very unlikely to get sick from this virus again. The virus antigenicity may change next season, like the flu virus does, and need a new exposure for new protection to develop. 

My advice is to pay attention to mortality reports (the current average is around 2 percent, but up to some 10-20 percent in mostly seniors, and particularly those already with medical problems.) Corona is not present in this area, yet, so you can’t get it, now. But it needs to be confirmed by a good test (one of the tests has a 3 percent error rate). I would also follow the other advice from reputable media, medical experts, the Communicable Disease Center, but not conspiracy theory, rumor sources, or politicians. 

Staying away from high-density public gatherings and particularly coughing and sneezing people - and doing grocery or other shopping at off hours - might be a whole lot better than face masks being sold now for recently increased outrageous prices. All this might help cut down your chances of getting the flu, too.  For one comparison, Eastern Equine Encephalitis is much worse at, they say, 50 percent death rate and 90 percent of those who get it do not recover. 

Arthur E. Sowers, PhD
research professor (retired)


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