In addition, the Skin Cancer Foundation estimates that a 5 percent decrease in the ozone layer will result in a 10 percent increase in biologically effective radiation from the sun, which could increase melanoma rates by 5 to 7 percent, basal cell cancer by 10 percent, and squamous cell cancer by 20 percent for those living in ozone-poor areas. Now, however, scientists are able to correlate contamination of the atmosphere with depletion of the ozone layer. There is no question that when the ozone layer is thinner, the rays from the sun are much more harmful. As we see the ozone layer thin, the ultraviolet radiation striking the Earth will increase, and there should be an associated increase in skin cancer. In South America, where they get more ultraviolet light coming through the ozone, they're seeing alterations in plant growth and in the life cycles of other animals.
Most experts agree that the thinning ozone theory has credence.
There's evidence to support this statement. And a 1991 Australian survey of adults who had noted one or more signs or symptoms of melanoma in the last five years found that only 57 percent of them consulted a physician. There's also evidence that people who understand the risk factors for skin cancer ignore the warnings. For example, a study of a skin cancer education program in the United Kingdom aimed at children aged 12 to 16 found no significant difference in sun-exposure behaviors between kids who were taught about the risk factors for skin cancer and those who were not. A French study found that 76 percent of mothers of preschoolers and 61 percent of adolescents knew that heavy sun exposure before age 15 causes skin cancer.