Frequently Asked Questions
How is UV bad for me?
UV radiation has several effects on the human body. Sunburn (erythema) has already been mentioned. More seriously, UV exposure is a risk factor for skin cancer, although the exact relationship between UV and skin cancer is complex. Malignant melanoma, the most dangerous type of skin cancer, seems to have an association with acute exposures i.e. bad sunburns, especially in childhood, while cumulative lifetime exposure is more clearly implicated for squamous cell carcinoma.
UV can also affect the eyes. In the short term an acute exposure can cause snow blindness (solar keratitis), while cumulative exposure contributes to cataract formation.
There is also some evidence that UV affects the skin-mediated part of the immune system, but this is a very complex subject and the effects, and their implications, are not easily identified in the way that one can recognise sunburn or cataracts.