When it comes to the sun’s rays, UVBs usually garner all the attention. After all, they’re the primary cause of sunburns and skin cancer, including melanoma. But UVA rays aren’t innocent. They, too, damage DNA and collagen.
The Truth About UVAs
Sunlight has many different types of rays, but its ultraviolet (UV) rays cause the most sun damage. Two types of UV rays—UVAs and UVBs—reach the earth’s surface. Although UVA rays aren’t quite as villainous as their counterpart, you should take notice of their effects and know how to protect yourself from them.
In sunlight, UVA rays outnumber UVBs by approximately 500 times, composing 90 to 95% of the UV radiation that reaches the earth. Their wavelength is longer than UVB rays’ wavelength, so they have less energy. UVB rays are strongest between 10:00 a.m. and 4:00 p.m. and from April to October. UVA rays, on the other hand, are equally present throughout the day and year, and they aren’t filtered by the ozone. They’re also highly present in tanning bed lamps.
UVA rays penetrate more deeply into skin—causing wrinkles, darkening and other forms of premature aging. Damaging to DNA, they also can be responsible for skin cancer.
Unlike UVB rays, UVA rays can penetrate through glass. Therefore, it’s important to protect your skin even when you’re driving. (Ever wonder why some adults have more freckles on their left side than their right? The unbalanced skin damage is from UVAs streaming through the driver’s side window.) Tinted windows block almost four times more UVAs than untinted, and a broad-spectrum sunscreen also helps.
Protecting Yourself from UVA Rays
It’s important to protect yourself from UVAs, but most chemical sunscreen is more effective at blocking UVB rays. In fact, SPF only measures UVBs, not UVAs. To ensure you’re guarding against UVA rays, make sure your sunscreen is labeled as “broad spectrum.” Also, look for the active ingredient zinc oxide because it physically, not chemically, helps block both kinds of rays.
UVAs can penetrate fabric, as can UVBs. Therefore, it’s important to apply sunscreen under clothes and consider washing your clothes with Sun Guard or a similar laundry aid that increases UV protection. UPF (ultraviolet protection factor) clothing is another great way to protect your skin.
For further protection, don’t forget to shade your face with a broad-brimmed hat and shield your eyes with UV-blocking sunglasses.