Solar UVB radiation is prejudicial to the health of humans in a number
of ways. Erythema and photodermatoses are acute reactions of the skin
; keratitis and conjunctivitis are acute reactions of the eye. Various
types of skin cancer, accelerated aging of the skin, and cataract for
mation in the crystalline lens are reactions that appear with great la
tency. UV radiation can also cause damage to the immune system and DNA
. For the period 1981-1991, an increase in erythemal effective UVB rad
iation of +(7+/-4)% per decade was measured in a non-polluted high mou
ntain area (Jungfraujoch, 3576 m a.s.l., Switzerland). This increase i
s related to a decrease in stratospheric ozone. The effects on human h
ealth are discussed. A 10% ozone reduction increases non-melanoma skin
cancer by 26% and cataract by 6 to 8%.