Skin cancer is the most common malignancy in humans [1]. Furthermore, Armstrong and Kricker [2] have calculated that in white populations over 90% of cutaneous malignant melanomas are caused by sun exposure. Similar proportions of both basal cell carcinoma and squamous cell carcinoma of the skin are likely attributable to sunlight exposure [3]. Because of the high proportion of skin cancer caused by sunlight, prevention programs have become increasingly common not only in high incidence areas such as Australia [4,5], but also in lower incidence countries such as Canada [6], the US [7,8] and the UK [9].
