[kodachrome64]

Radiation safety, including UV safety, operates on the As Low As Reasonably Achievable (ALARA) principle - "This principle means that even if it is a small dose, if receiving that dose has no direct benefit, you should try to avoid it." [1] I'd imagine that this is the principle that the American Academy of Dermatologists bases their guidance on. Skin colour has nothing to do with it; radiation = bad.

It's generally a damned good principle to live by. We know for certain that higher UV exposure = higher risk of melanoma. It may be a lower risk for people with darker skin, but where do you draw the line for how dark is dark enough to not need to bother with sunscreen? The article states that it's rare in African Americans, but not nonexistent. In the absence of other evidence, why not avoid UV exposure?

This article presents emerging studies that suggest that UV exposure does have some direct benefits and that avoiding it may be especially harmful to people with darker skin. If there's enough evidence to support the findings, the AAD should absolutely change its advice. That's the scientific process. The article uses the example of margarine to illustrate the point; we've gotten it wrong before.

Given the above, are you certain that the term "racism" is accurate here? What can we attribute to bias that can't be explained by a lack of scientific evidence?

[1] https://www.cdc.gov/nceh/radiation/alara.html