Sunscreen produces persistent free radicals when exposed to light, study finds https://phys.org/news/2026-03-sunscreen-persistent-free-radicals-exposed.html

Research from the Department of Environmental Health Sciences explores how common sunscreen ingredients behave under light exposure. Led by associate professor Eric Vejerano, the team tested seven commercially available sunscreens (including four mineral-based formulas) and found that every sample produced persistent free radicals (PFRs) when exposed to artificial light. The study, published in Environmental Science & Technology Letters, provides new insight into sunscreen photochemistry and may help guide future evaluations of product performance and safety.
#Runners: is there a brand of long sleeve, hot weather running shirt (think UPF) that you prefer? I need to start wearing sleeves and cover more skin. But I also don't want to be hot.
#Sunscreen isn't enough at altitude.
*edit: there are some good cheap options on Amazon. I should add that I'd rather not spend a lot on a patagonia shirt, etc