UV Cleaning Technologies

UV-C. Its Power, its History and Role in HAIs

Ultraviolet light is invisible to the human eye. It exists on the electromagnetic spectrum and is usually thought of in relation to x-rays and sunburn.

UV-A and UV-B wavelengths are the ones that most people are accustomed to. UV-C is a more powerful form. It has a wavelength of 254nm (nanometers). This means that on contact with an organism it has the ability to cause lasting damage to DNA, effectively killing the cell that comes in contact with it.

It doesn’t take long for UV-C light to do its job. Even very brief exposure (a matter of seconds) has the capability to eliminate microbial replication.

For this reason, it is the most sought-after technology to eradicate viruses and bacteria.

The minute a microorganism absorbs UV-C, dimerization takes place. Dimerization of molecules is the type of damage caused by UV-C light in microorganisms.  In chemistry, a dimerization is an addition reaction in which two molecules of the same compound react with each other and inevitably bind; meaning that no molecule escapes.

This means that UV-C light not only destroys but also disintegrates a microbial germ, giving it the suitable title of a germicide.

The first discovery of the effectiveness of ultraviolet light was made in 1877 in Britain, when two scientists put solution-filled test tubes outside and noticed that sunlight both killed and inhibited the development of pathogenic bacteria.

Since then UV-C technology has been used to kill microorganisms responsible for poor indoor air quality – bacteria, mold, yeast and viruses.

In the late 1930s the installation of upper room UV-C lamps in classrooms saw a major reduction in the outbreak of measles.

Its use became very widespread, killing a range of viruses and bacteria including E-coli. UV-C played a major role in the eradication of TB.

Healthcare associated infections are more common than people know. These are infections that were not present in a person prior to them visiting a healthcare establishment.

HAIs can be contracted at hospitals, doctors’ offices, long-term care facilities and ambulatory surgical centers.

In a hospital, more than half of all HAIs occur outside of the intensive care unit. They can be caused by bacteria, viruses, fungi or parasites.

Those at higher risk for contracting HAIs are the elderly, young children and persons with compromised immune systems.

20-40% of HAIs stem from the transmission of pathogens by a healthcare worker.

A study published in the American Journal of Infection Control found that patients admitted to rooms that previously held a patient infected with a multi-drug resistant organism were more likely to contract that infection.

In the study researchers used over 3,000 microbial samples from 3 hospitals in the NY area.

Donna Armellino, lead author of the study and VP of Infection Prevention at Northwell Health, New York’s largest healthcare provider says of UV-C light…

“This technology can optimize environmental cleanliness, resulting in decreased pathogens that could potentially cause infection.”

Duke University Medical Center conducted a study between 2012 and 2014 to help find ways to mitigate the HAI rate of contraction and the additional cost incurred by healthcare facilities.

9 hospitals were tested during the period. The tests were randomized between cleaning with bleach or an ammonium solution (the standard disinfection that hospitals have been using for years) to the incorporation of UV-C light.

At the end of the study, all of the participating hospitals reported at least a 30% decrease in HAI cases.

If hospitals make UV-C technology a part of their standard disinfection protocols, preventing 30% of infections per year (55 per year) for two years, the cost savings would be US$2,085,000.

Hospitals in the study noted in particular that patient rooms saw the greatest turn around.

This was attributed to the fact that the UV-C light reaches ‘hidden’ areas such as under beds, in stands, sinks and the corners of open cabinets and drawers.

With respect to HAIs, the bottom line is that human error and other drawbacks of standard chemical disinfection can be eliminated with the use of UV-C technology.