Many people worrying if ultra violet radiation causes skin cancer. The fact is, the light has to hit your skin for it to damage you, and the light will be encased inside of it. Also, you don't immediately get cancer even if some UV light hits you. If you are never exposed to ultraviolet light, your body can't make Vitamin D and you run the risk of getting rickets or other diseases.
I'll inform you the importance of ultraviolet air cleaners. Ultraviolet light is a wavelength of light that you've probably heard of because it's what causes sunburns. In a cleaner, though, it's a good thing - it doesn't just hurt your skin cells, but also kills germs.
Today there are many Ultraviolet Air Filtration Systems, some of them do not use UV light to kill germs, they are labeled as using UV, but they use it to generate ozone which then kills the germs. This is a different issue health-wise. The EPA (the Environmental Protection Agency) has warned that this could be dangerous in closed in areas. Make sure if you're getting one, it isn't an ozone generator.
Look this 2 brands of ultraviolet air cleaners. Honeywell HHT-145 UV Antibacterial Tower and Germ Guardian GG-1000 Air Sanitizer. Find more information at http://www.aircleanersguide.com/uv-air-purifier.htm