SGoing without screens is an important way to protect people from skin cancer and other harmful effects of ultraviolet (UV) rays. But some chemicals, or filters, in sunscreens have been under scrutiny lately because of their potential impacts on the environment and human health. Most of the concern has focused on the ingredients in chemical sunscreens — such as oxybenzone, avobenzone, octocrylene, homosalate, octisalate, and octinoxate — that absorb ultraviolet (UV) light.
Physical, or mineral, sunscreens – consisting of only zinc oxide and titanium dioxide as active ingredients – are of little concern for human health safety, as they block UV rays by staying on top of the skin and deflect them.
There are also concerns that oxybenzone and other sunscreen chemicals can cause coral bleaching and harm aquatic life when they wash up and get into the water.
One report published on August 9 by the National Academies of Science, Engineering, and Medicine concluded that although people should continue to use sunscreen — and indeed, use it more often — it is necessary to There is additional research on some safety aspects of its active ingredients.
Here’s what the report says about sunscreen and its implications for human health and the environment.
Sunscreen is not used
Only about one-third of people in the US regularly use sunscreen, the report found, although between 70 and 80 percent of Americans use it when they’re at the beach. However, most sunscreen users don’t apply enough — the American Academy of Dermatology recommends using an ounce for full body coverage — and often don’t reapply every two hours, as recommended. In addition, white Americans use sunscreen more often than people of color, who have a lower incidence of skin cancer than whites but more likely to die of disease.
Read more: The safest sunscreens to buy — and which ingredients to avoid
The best available evidence — obtained through large randomized controlled trials and longitudinal observational studies — shows that a broad-spectrum sunscreen (meaning it protects against both UVA and UVB rays) with SPF higher than 30 reduces the risk of skin cancer, sunburn, and aging caused by sun exposure. However, sunscreen should be used in conjunction with other precautions, such as wearing a hat, avoiding sun exposure during the hottest times of the day, and seeking shade.
There are not enough safety studies
Scientists have found no more harmful effects in adults than the benefits of using sunscreen. But the report’s authors argue that more research is needed on safety, as the US Food and Drug Administration (FDA) studies published in 2019 and Year 2020 found evidence that many of the chemical filters in sunscreens penetrate the skin and can stay there for days. While this doesn’t necessarily mean that the chemicals are dangerous, some have been found in the body in concentrations above the FDA-set upper limit, and studies on them are needed. safety. Homosalate and oxybenzone, both of which absorb UV light, were higher than that three weeks after application in one study. Several animal studies have also raised concerns about UV filters, including changes to hormones and gene expression. The report’s authors also point to several gaps in human safety research; For example, safety studies did not follow people for long periods of time, meaning they could not consider potential outcomes that may emerge over time, such as cardiometabolic risk. , cancer risk or fertility problems.
Overall, however, the weight of scientific evidence favors sunscreen use, the authors conclude. Scientific reviews that have examined various studies on the use of UV filters have found encouraging indications that the filters are safe for human consumption. Reviews have not yet concluded that high concentrations of UV filters harm male or female fertility, female reproductive hormone levels, fetal growth, or neurological development. of children. “To date, no levels of toxicity have been found in humans that outweigh the benefits of these filters in reducing overexposure to [ultraviolet rays],” the authors wrote. “However, the authors all recognized a significant data gap.”
The effects on other species are also worthy of further study
While scientists have examined how sunscreen chemicals affect a number of plant and animal species, data on many other important species, including corals, are lacking, say the scientists. ho, the authors said. They argue that more testing is needed on how toxic sunscreen ingredients are to different marine life, especially in areas where exposure may be more vulnerable. These include coral reefs in shallow areas near places where people do many recreational activities, such as swimming; in slow-moving freshwater environments where recreational activities are also available; or in areas exposed to sewage.
How sunscreen works in the real world
The report’s authors say scientists need to learn more about the actual impact of chemicals in sunscreens on the environment. For example, while some UV filters (including avobenzone, dioxybenzone, and octocrylene) have been shown to take a long time to biodegrade when they are tested in the lab, researchers should check them out. how they accumulate in nature, such as by sampling organisms and soil, the authors write.
Another priority should be to examine how natural stressors such as climate change and pollution interact with sunscreen chemicals present in the environment. The scientists say more research is needed into what happens when ecosystems are subjected to multiple types of stress at the same time, as well as what happens when UV-filtering chemicals are combined with other threats, such as rising temperatures and contaminants.
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