UV light: How harmful is it and how you can use it safely and effectively

UV light has become prominent in the new normal, especially since it is said to effectively kill viruses and bacteria.

But UV light disinfection is complicated and carries with it certain dangers. 

In a report on Pinoy MD, Dr. Jay Racoma said that UV light really does a "germicidal effect," which means it kills viruses and bacteria.

"Now how it works is that this wavelength alters the outer protein of a virus altering the material of the said viruses," Racoma said.

"This will then stop the replication of the DNA and RNA exposing damage to the genetic material so that they don't replicate. It effectively inactivates the virus," he added.

Racoma said its effect is the same as whatever the UV sheds its light on and as such, it can be damaging to the eyes.

"The effect of UV resiliation is the same way is the effect of the sun causing sunburn on our skin," he said.

Several instances have happened amid the new normal wherein the UV light has caused harm to humans.

How harmful is UV light to humans?

For instance, a recent media coverage where a robotics company had a demo of their UVC disinfectant machine caused harm to not less than eight members of the media after the coverage.

According to the report, all of the attendees were in one area without eye and skin protection.

One of the attendees said he suddenly experienced pain in his eyes to the point that he couldn't open them.

"Hindi ko na siya madilat kapag dinilat ko siya puti lang nakikita ko, hinilamusan ko ng hinilamusan ko ng tubog wala pa rin talaga, may something na parang mabuhangin sa loob may something na parang may bubog sa mata," he narrated.

Just recently, Kapuso hunk Derek Ramsay also had the same experience, looking briefly straight into the UV light as he was fixing it inside their house.

While the effect wasn't immediate, Derek shared feeling a burning sensation in his eyes and being unable to open them a few hours later. 

According to Dr. Jay, in most cases this is called the "Photokeratitis or Photoconjunctivitis" which is temporary, but when prolonged it can cause more damage and require surgery.

"If you have direct exposure to the sunlight or direct exposure to UVC, this can lead to cataract formation and this will actually require surgery," he said.

"In the eyes we have the outermost covering, this is the conjunctiva, which gets affected and damaged by the UV," he said.

How to safely use UV light for disinfection

Despite the dangers, PinoyMD said it cannot recommend stopping the use of UV disinfection.

Instead, the doctor gave his recommendations on how to properly and safely use the UV light.

If you are planning to use UV lights to disinfect a whole room, he suggests the person to vacate the room.

"Some of these machines also emit ozone that will technically also irritate the respiratory system no they can cause difficulty in breathing," he said.

According to Food and Drug Authority USA, the UVC light is most effective against bacteria and viruses.

Despite the DOH recommending UV light disinfection best in healthcare settings, more and more people have included UV light in their arsenal at home to fight off COVID-19. — Jannielyn Ann Bigtas/LA, GMA News