Prolonged exposure to UV-B light can cause sunburn, and there are worries that damage to the ozone layer may lead to an increase in the incidence of skin cancer.
UV-B light is not naturally occurring
It comes from the sun. I think the system had difficulty because I used unfamiliar phrasing
( z1 natural :polarity - :ARG1 ( z2 light :mod ( z3 ultraviolet-B ) ) )