What are the advantages and disadvantages of ultra violet rays in our health or on our daily living?

Answer 1

UV rays have only one advantage in comparence with visible rays: they kills much of viruses and bacteries, which can do some problems to us.
But there are some negative influences of UV rays: they can break our scin, eyes...
That's wy I think that UV rays don't have place in our life, exept "solaries"...

Answer 2

You need some for your body to produce vitamin D. Too much and you risk sun burn and skin cancer.