WASHINGTON - A sunscreen that blocks the type of ultraviolet radiation linked to some cancers, and which has been available only outside the United States, received federal approval Monday. Called Anthelios SX, the sunscreen contains ecamsule, an ingredient better at blocking ultraviolet A, or UVA, radiation than other sunscreen ingredients currently sold in the United States. Those ingredients mainly screen out UVB rays. UVB has long been associated with sunburn, while UVA is recognized as a deeper penetrating radiation, according to the Food and Drug Administration. Doctors suspect there is a link between UVA exposure and longer-term effects, including wrinkles,...