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After a single application, a total of seven chemicals commonly found in sunscreens can be absorbed into the bloodstream at levels above safe thresholds, according to studies from the Center for Drug Evaluation and Research, a branch of the Food and Drug Administration. United States Drug Administration.
“What is most alarming about these results is that the chemicals are absorbed into the body in significant amounts and the ingredients have not been fully tested for safety,” said David Andrews, scientist. principal for the Environmental Working Group, or EWG, a consumer organization. which advocates the safety of sunscreens.
“If companies are to keep these ingredients in their products, they urgently need to test for potential risks to children and damage from long-term use,” Andrews added.
Just because an ingredient is absorbed through the skin and into the body doesn’t mean that particular ingredient is dangerous, said Dr. Janet Woodcock, director of the Center for Drug Evaluation and Research, the branch of the FDA that conducted the reviews. studies.
“Rather, this discovery calls for additional industry testing to determine the safety and effect of systemic exposure to sunscreen ingredients, especially with chronic use,” said Woodcock.
Experts and the FDA point out that the sun’s link to cancer and aging is real, so don’t give up on sun protection. Suggestions include long-sleeved clothing, hats, sunglasses, and staying in the shade. If you’re worried about chemical sunscreens, consider mineral-based sunscreens, which the FDA says are generally considered safe and effective.
The American Academy of Dermatology recommends applying at least 1 ounce of sunscreen to all exposed skin every two hours or after swimming, including “back, neck, face, ears, tops of your skin. feet and legs ”.
Confirmation of previous study
The findings of the FDA, published Tuesday in the journal JAMA, confirmed the results of a pilot study published by the agency last year. This pilot study found that four popular chemical sunscreens often used in commercial products – avobenzone, oxybenzone, octocrylene, and ecamsule – were absorbed from the skin into the bloodstream after just one day of use.
The new study reassessed three of the original four (avobenzone, oxybenzone, and octocrylene) and added three additional sunscreen chemicals – homosalate, octisalate, and octinoxate.
All of these chemicals are part of a dozen that the FDA wants manufacturers to research before they can be considered GRASE or “generally considered safe and effective.”
Participants in the new study were asked to apply sunscreen to 75% of their body on the first day. On days two through four, they were asked to apply the same amount four times during the day.
After the initial absorption, the concentration of all six chemicals in the blood increased on each day of application and remained above FDA safe levels by day seven, well after the end of application. Two of the chemicals – homosalate and oxybenzone – were still above safe limits on Day 21.
“It seems likely that some of it is absorbed into the bloodstream long after sunscreen is applied and that is part of why blood levels remain high for weeks after application,” Andrews said.
“The skin is not a perfect barrier and so one should expect absorption of small amounts of chemicals from sunscreens (and other skin care products such as cosmetics),” said said Rob Chilcott, professor of toxicology at the University of Hertfordshire in the UK.
“This does not mean that sunscreen products are dangerous to use, but that proper safety tests must be carried out by manufacturers,” he added.
Sunscreen industry associations have said they will continue to work with the FDA to determine additional studies needed to ensure the continued safety of the active ingredients in sunscreens.
“The presence of these ingredients in plasma does not suggest a safety concern and no serious drug-related adverse events were reported in the trial,” said the Personal Care Products Council and the Consumer Healthcare Products Association.
Dangers of the sun
One in five Americans will develop skin cancer before the age of 70, according to the Skin Cancer Foundation. Globally, melanoma is the 19th most common cancer in men and women, according to the World Cancer Research Fund.
In the United States, sunscreens were initially approved as an over-the-counter sunburn solution. There are two types: one using chemical combinations to filter the sun, the other using minerals to block the sun such as titanium dioxide or zinc oxide, which leave a telltale white coating. With many people unwilling to sport a white shade, the popularity of chemical sunscreens has skyrocketed.
Due to the way they were used at the time, there wasn’t much concern about a potential health impact. But that quickly changed and the FDA started asking the industry for safety testing.
Critics say they’ve dragged their heels over the years, pushing the FDA to do the first studies.
“The FDA is stepping up the pressure on sunscreen manufacturers by performing its own tests and finding that the most common chemicals in sunscreens are absorbed through the skin and into the blood at levels that can cause damage,” said Andrews of the EWG.
Chemical absorption levels
The skin absorption levels of three of the study’s chemical sunscreens – homosalate, octisalate, and octinoxate – in commercial sunscreens had not been studied before, the FDA researchers wrote in the study.
However, they pointed to studies that have “raised questions about whether oxybenzone and homosalate” might affect hormonal activity.
In the 2019 study, “oxybenzone was absorbed into the body at about 50 to 100 times the concentration” than others tested, Andrews said.
Research has shown a potential link between oxybenzone and lower testosterone levels in adolescents, hormonal changes in men, and shorter pregnancies and disrupted birth weights in babies. However, the researchers caution against hypothesizing an association between exposure and these results.
A 2008 Swiss study found oxybenzone or one of four other sunscreen chemicals in 85% of breast milk samples, raising concerns about newborn exposure. A 2010 study found another of the chemicals studied, octinoxate, in breast milk.
In 2008, the United States Centers for Disease Control and Prevention analyzed urine samples collected by a government study and found oxybenzone in 97% of the samples.
Of all the ingredients in sunscreen, oxybenzone is known to be the most common cause of contact allergies; a 10-year study found that 70% of people had a positive patch test when exposed.
The European Union has mainly replaced oxybenzone in its sunscreen products with newer, more protective substances that further block harmful UVB and UVA rays. But these new products did not pass the necessary safety tests for FDA approval. Oxybenzone therefore remains in use; in fact, a 2018 report from the EWG estimated that it was present in two-thirds of all chemically-based sunscreens sold in the United States.
A disturbing impact
All of these negative results – and the publicity that came with them – could have a worrying outcome in cancer prevention, said Dr. J. Leonard Lichtenfeld, deputy chief medical officer of the American Cancer Society.
“The public sees the headlines saying ‘the FDA is concerned’ and then wonders if sunscreens are safe,” Lichtenfeld said.
Additionally, Hawaii, the Pacific Nation of Palau, and Key West have banned sunscreens containing oxybenzone and octinoxate because they cause coral bleaching and are dangerous to marine ecosystems. This adds to the public unease about sunscreens, Lichtenfeld said.
“These two issues in parallel have raised concerns within the sun safety community that people will ditch sunscreen as a means of sun protection,” Lichtenfeld said.
In its statement, the FDA also winked at this concern.
“Given the recognized public health benefits of using sunscreens, the FDA urges Americans to use sunscreens in conjunction with other sun protection measures (such as protective clothing),” said Woodcock said.
The EWG, which publishes a guide to sunscreen safety, recommends choosing mineral sunscreen that contains titanium dioxide and zinc oxide when possible, while the American Academy of Dermatology recommends speaking to a certified dermatologist if you are concerned about the safety of sunscreen ingredients. .
Both organizations say there are ways to protect yourself and your family other than sunscreen. Look for shade, especially between 10 a.m. and 2 p.m. when the sun is hottest and any time your shade is shorter than you. Use protective clothing, such as long-sleeved shirts and pants and a wide-brimmed hat, and don’t forget sunglasses.
“It’s important for us to note that sunscreen is part of safe sun behavior, but certainly not necessarily the most effective way to prevent sun damage,” Lichtenfeld said.