Moore’s argument is only about whether the sunscreen lotions effectively block cancer-causing UV radiation. Whether they have other health benefits is irrelevant.

This is true, but it doesn’t weaken Moore’s argument. She argues that sunscreen doesn’t effectively block UV radiation because sunscreen users get skin cancer just as much as non-users. The severity of those cases is irrelevant.

Moore’s conclusion only addresses sunscreen lotions that are specifically designed to block cancer-causing UV radiation. The effectiveness of any other sunscreen lotions is irrelevant.

The evidence that Moore cites may not support her conclusion well, but there’s no reason to believe that it would be impossible to challenge.

Moore concludes that sunscreen is ineffective because both sunscreen users and non-users get the same amount of skin cancer. She overlooks the possibility that there might be some other relevant difference between these groups, like sunscreen users spending more time in the sun.