OZ3C. Stay Current—The Dangers of UV to Living Things

2023-07-15. Why Sunscreen Is the Only Anti-Aging Product You Need. [https://www.nytimes.com/2023/07/15/well/live/sunscreen-aging-skin-care.html] By Dana G. Smith, The New York Times. Excerpt: …Dr. Frey said that as much as 80 percent of the skin changes we associate with age are actually caused by the sun’s ultraviolet rays. The best way to avoid them, aside from staying indoors, in the shade or permanently covered up? Sunscreen. …Years of exposure to both UVA and UVB rays damages cells on the top layer of the skin, called keratinocytes. When that happens, the skin starts to look red, rough and scaly in patches — a condition called actinic keratosis. “It’s due to DNA mutations that occur specifically in the keratinocytes, and they then proliferate and become abnormal,” said Dr. Lena Von Schuckmann, a dermatologist and clinician researcher at the University of Queensland in Australia. In some cases, actinic keratosis can become cancerous. …Below the keratinocytes are the melanocytes — the cells that produce melanin and cause the skin to darken. UVA rays primarily activate these cells, resulting in a suntan. (Sunburn is different; it’s caused by UVB rays injuring the top layer of the skin.) With long-term UV exposure, the melanocytes become damaged, resulting in permanent hyperpigmentation. These brown spots are sometimes called sunspots, age spots, liver spots or their technical name, solar lentigines….

2020-09-28. Flower colors are changing in response to climate change. By Lucy Hicks, Science | AAAS. Excerpt: research [https://www.cell.com/current-biology/fulltext/S0960-9822(20)31267-7] suggests that over the past 75 years, flowers have also adapted to rising temperatures and declining ozone by altering ultraviolet (UV) pigments in their petals. Flowers’ UV pigments are invisible to the human eye, but they attract pollinators and serve as a kind of sunscreen for plants, says Matthew Koski, a plant ecologist at Clemson University. Just as UV radiation can be harmful to humans, it can also damage a flower’s pollen. …pigment in flowers at all locations increased over time—an average of 2% per year from 1941 to 2017, they reported this month in Current Biology. But changes varied depending on flower structure. In saucer-shaped flowers with exposed pollen, like buttercups, UV-absorbing pigment increased when ozone levels went down and decreased in locations where ozone went up. But flowers with pollen concealed within their petals, such as the common bladderwort, decreased their UV pigment as temperatures went up—regardless of whether ozone levels changed. Though surprising, the finding “makes total sense,” says Charles Davis, a plant biologist at Harvard University who was not involved with the work. Pollen hidden within petals is naturally shielded from UV exposure, but this extra shielding can also act like a greenhouse, trapping heat. When these flowers are exposed to higher temperatures, their pollen is in danger of being cooked, he says. Reducing UV pigments in the petals causes them to absorb less solar radiation, bringing down temperatures…. [https://www.sciencemag.org/news/2020/09/flowers-are-changing-their-colors-adapt-climate-change] 

2009 October 19. Color of Fabric Matters When Protecting Skin From Ultraviolet Rays. By By HENRY FOUNTAIN, The NY Times. Excerpt: It takes more than sunscreen to keep the sun’s ultraviolet rays from harming your skin. The type of clothing you wear can offer protection, too — or not. Studies have shown that some lightweight fabrics do not provide enough UV protection.
But it is not just the type of fiber and the weave of the fabric that matters, but also the color. Ascención Riva of the Polytechnic University of Catalonia and colleagues have addressed the color issue, studying the effects of different dyes on the UV protection provided by lightweight woven cottons.
…They found that red and blue shades performed better than yellow, particularly in blocking UV-B rays, which are the most harmful. Protection increased as the shades were made darker and more intense. And if the initial protection level of the fabric was higher, the darker shades offered even greater improvement…. 

2001 August 12. NEWSWEEK COVER: JOHN MCCAIN: MY BATTLE WITH SKIN CANCER In the August 20 issue of Newsweek, Arizona Sen. John McCain and his wife Cindy talk about his battle against skin cancer. An accompanying report looks at the increase in skin cancer, new treatments being tested and a tribute to Maureen Reagan who died from melanoma. 

Dermatlas is an international collaborative project that enables health care professionals, parents, and patients to access high quality dermatology images on the World Wide Web. The Dermatlas also includes an online Dermatology Quiz that allows trainees to test their diagnostic skills.