Sunscreen usage is climbing, but so are melanoma and skin cancer rates: this, researchers say, is the sunscreen paradox.

“The problem is that people use sunscreen as a ‘permission slip’ to tan,” said Dr. Ivan Litvinov, an Associate Professor in the Department of Medicine and Chair of the Dermatology Division at McGill University and co-author with Dr. Sandra Peláez, Dr. Richie Jeremian and Dr. Pingxing Xie of two recent studies that explore the sunscreen paradox.