[pct-l] Study on effectiveness of umbrella for UV protection

[Betty Wheeler]

This study demonstrates the effectiveness of all umbrellas (and not just
ones with special coating like the Chrome Dome) in providing UV protection.
http://www.today.com/health/sun-umbrella-can-protect-against-harmful-rays-1C8995807

According to a U.S. study published in JAMA Dermatology, any
fully-functioning handheld umbrella can block more than three-quarters of
ultraviolet (UV) light on a sunny day. Black ones do even better, blocking
at least 90 percent of rays... . [Researchers] collected 23 working
umbrellas - no fabric tears allowed - from people at their medical school.
On a sunny morning they used UV devices to measure radiation just under
each umbrella's fabric, and by the nose of the person using it - and then
compared this to umbrella-less radiation readings.

All but one of the umbrellas was a standard, handheld rain umbrella. The
other was a travel sun umbrella.The sun umbrella blocked more than 99
percent of UV rays. Regular umbrellas worked well too, blocking at least 77
percent of UV light - and more, if the umbrella was darker coloured.

​So: at least 77% block from any umbrella without tears in the fabric; at
least 90% from a black umbrella; and 99% from a travel sun umbrella.​

--Betty