How do we balance the good and bad effects of sunlight on human health?
In general, moderate exposure to sunlight in the course of everyday life is not detrimental. This basic exposure evidently allows us to function normally, and it proves to be sufficient to maintain an adequate level of vitamin D (in combination with our dietary intake). While sunlight is important for physical health it also causes various adverse health effects such as skin cancer, aging of the skin, eye disorders and suppression of the immune system. It is clear that excessive UV exposure should be avoided to minimise the risk of development of such disorders. • How strong is the evidence that UV-B radiation causes skin cancer in humans? The evidence is strong. The earliest experimental evidence that UV-B radiation causes skin cancer was acquired with animals; in humans there was a clear association between sun exposure and skin cancer, but that did not point specifically to UV-B. In recent years the advancement of molecular biology has provided us with analyses that produce direct e
