The standard, pro-sunscreen explanation is that, like lung cancer, the disease has a long lag time, on the order of 20 years. Americans began sunbathing in earnest in the 1950s, and as a result, the melanoma epidemic hit in the 1970s. But even a cursory look at the history of sunbathing washes this explanation away faster than a sand castle in a hurricane. Ask any elderly person you know. Beaches around the country were jammed on summer weekends in the 1930s.
Sunscreen promoters offer no clue.
Beach Bummer New evidence suggests that sunscreens don't prevent skin cancer and may even promote some forms of it. The manufacturers know it. Some researchers know it. Even worse, the Garlands' research suggests that sunscreen use just might promote melanoma. Unfortunately for the public health, the Garlands refuse to discuss their theory for fear of professional ostracism.