"We don’t want people to just stay inside," said Dr. Lawrence F. Eichenfield, a professor of dermatology and pediatrics at the University of California, San Diego and Rady Children’s Hospital. "We know that sun can have harmful effects including increasing the risk of skin cancer, sunburn, aging of skin -- sun protection makes sense."
Dr. Miriam Weinstein, a pediatric dermatologist at SickKids (The Hospital for Sick Children) in Toronto, and an associate professor of pediatrics and medicine at the University of Toronto, said: "We know from research that much of a lifetime of sun exposure occurs in childhood." But the outcomes that we’re trying to prevent, whether carcinogenesis or just sun-related aging of the skin, occur much later in life, and trying to change behaviors is more difficult, she said, when a bad outcome seems remote.
Many parents are also familiar with recent reports about the possibility that chemicals in sunscreens may be absorbed into the bloodstream.
A study published in May in JAMA found that when adults applied the maximum recommended amounts of sunscreen, chemicals were absorbed into the blood and accumulated; that is, blood levels rose over the course of several days. This does not show that any of these substances are dangerous, but it does indicate that they should be more carefully studied; the Food and Drug Administration has proposed additional regulation.
But in the meantime, it’s summer, and the consensus advice from physicians, including dermatologists, and from the F.D.A., is that protecting against sun exposure remains the main imperative.
"We don’t want mixed messages to come out that people shouldn’t use sunscreen or should avoid sunscreen," Dr. Eichenfield said. "That could lead to increases in skin cancer and other secondary sun effects."
So how can parents best reduce the risk? You know what I’m going to tell you here, but it’s worth repeating that every dermatologist, asked about sun protection, starts the conversation a long way from sunscreen.
Dr. Weinstein started with "seeking shade, avoiding the most intense hours of sun exposure, hats, clothing coverage, and then sunscreen." Still, she said, especially when it comes to children, "a lot of those other strategies are less convenient; the clothing can be hot, or the kids don’t want to wear sun protection bathing suits, or the preschoolers won’t keep their hats on."
Dr. Eichenfield, who is the past president of the Society for Pediatric Dermatology, called it "having a broad perspective on sun protection."
When it comes to sunblock, the safest, from the point of view of absorption, are "physical sunscreens," based on titanium dioxide or zinc, which do not get absorbed like chemical sunscreens.
"The scientific studies still support use of sunscreen to protect against skin cancer, and people who want to be informed should be aware that titanium dioxide and zinc have been judged to be safe," Dr. Eichenfield said. "They’re not found in the bloodstream, they stay on the skin, they block the sun, there’s no evidence of them being absorbed systemically."
They are also much more visible on the skin, and many children -- and adults -- prefer the less visible chemical products. And if the physical blockers are broken down into nanoparticles, to make them more cosmetically acceptable, the concern is that then they also may be absorbed.
There are also some chemicals in sunscreen that have provoked concerns about environmental effects; a law in Hawaii which will take effect in January 2021 bans two chemicals, oxybenzone and octinoxate, which can harm coral.
So the message is to choose your sunblock and then use it, after taking advantage of the other sun protection strategies. "Any skin that gets exposed and can’t be protected by hats and shade and clothing should be protected liberally with sunscreen," Dr. Weinstein said.--TheNewYorkTimes