A whole book on the actinic rays of the sun!

I’m always on the lookout for books that take a more balanced view of sun exposure than “skin cancer bad,” and this looks to be a good one: In Defense of Sunlight: The Surprising Science of Sun Exposure by Rowan Jacobsen

From a review in Nature Briefing:

“One study he mentions analysed the skin of lifeguards at the start and end of a summer season during which they were heavily exposed to the sun. By summer’s end, their skin was enriched with microbial “beneficial bugs” that protect against UV radiation. A square centimetre of human skin contains millions of microorganisms, some of which produce compounds that kill cancer cells without harming normal ones.”

Source: The best way to start your day? The science backs naked cartwheels in the sun

I mean, really. We know the UV rays are actinic, as are the blue-green rays (tell your brain it’s daytime), and the red and infrared rays (promote healing at various depths of skin and below the skin). I don’t know about all the other wavelengths, but I’m willing to bet that they all do something.

Humans evolved in the sun, and evolved different skin pigmentation that varied with latitude (and, I suspect, varied with other things as well). The idea that our skin can’t handle a perfectly ordinary amount of sunlight is just silly.