As the years go by, many of us shy away from soaking up the sun. We turn to hats and long cover-ups, worshipping broad spectrum sunscreen over bronzing. And rightfully so, knowing that sun exposure causes up to 80% of the visible signs of skin aging.
But the sun isn’t public enemy number one. Its health benefits keep us energized and its mood-boosting effects give us that finally-summer-feeling we know and love. So if you’re curious about how to enjoy the sun while protecting your skin, learning about different types of solar and ultraviolet (UV) radiation is key. ( Check your UV index right now here! )
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What is the solar spectrum?
The sun plays a vital role in our health, contributing to our mental well-being and playing a role in the synthesis of vitamin D. But it also emits something called electromagnetic radiation. While some of it is absorbed, scattered, and reflected before it reaches us, the radiation that does arrive at the Earth’s surface is called the solar spectrum.
The solar spectrum is made up of different kinds of radiation which are measured and classified according to their electromagnetic frequencies. A few of them, like ultraviolet A radiation (UVA) and ultraviolet B radiation (UVB), should sound familiar. However, visible blue light and infrared radiation may also alter your skin’s appearance.
This solar radiation spectrum above ranges from the most powerful rays (ultraviolet) to the least powerful (infrared). Let’s find out how each affects your skin.
What’s the difference between UVA & UVB radiation?
Responsible for summertime tan lines, these rays mainly affect the skin’s surface. Exposure to UVB radiation occurs outdoors and varies by time of day, geographical location, and weather.
Although UVB radiation only reaches the outermost layer of our skin, it can also have lasting effects. Aurora Garre, MD, ISDIN Medical Director, explains that UVB radiation is “the main cause of short-term skin damage” such as sunburns.
Fortunately, our bodies’ antioxidant systems can help repair DNA damage caused by overexposure to UVB radiation. But, repeated sunburns can dampen our natural regenerative capacity, increasing our risk of skin cancer.
Main skin concern: Sunburns and their role in skin cancer
Where does exposure happen? Outdoors in all weather conditions, although levels vary
Extra credit: When we talk about SPF we refer to the sun protection factor against UVB radiation. Protection ranges from low (from 6 to 10 SPF), medium (15-25), high (30-50), to very high (50+).
On the other hand, “UVA radiation is responsible for long-term damage, such as photoaging and skin cancer,” says Dr. Garre. It deeply penetrates into the skin and breaks down collagen, contributing to the appearance of fine lines and wrinkles. UVA radiation can also produce photo immunosuppression and is the main cause of solar allergies.
Unlike UVB, UVA rays reach your skin even on cloudy days and inside your car, office, or house. So remember, it’s crucial to protect yourself daily, year-round.
Main skin concern: Signs of skin aging, sun allergies, and skin cancer
Where does exposure happen? Indoors and outdoors, year-round
Extra credit: Opt for sunscreen labeled as broad spectrum — meaning it meets FDA standards for UVA protection. And the higher the SPF, the higher the UVA protection will be too.
Can other types of solar radiation affect my skin?
We can thank this type of sun-power for the gift of sight. Blue light is a high-energy visible light within the range of radiation the human eye can see. Reaching us both indoors and outdoors, we’re exposed to blue sunlight every day.
But it’s not all good news. Recent studies have shown that blue sunlight is linked to the appearance of dark spots or uneven pigmentation, especially in people with darker skin tones. And its synergistic effect with ultraviolet radiation has also been found to pose harm to the skin.
Main skin concern: Dark spots and uneven pigmentation
Where does exposure happen? Indoors and outdoors, year-round
Extra credit: The damage that blue sunlight can cause has often been linked to the artificial blue light emitted by displays. But, don’t cancel that stream session just yet. Solar blue light is 100 to 1000 times more intense than the blue light emitted by screens — making upping your sunscreen use the priority over cutting screen time.
Used in physiotherapy treatments, this type of radiation can provide relief and reduce muscle pain with intense, localized heat.
But along with its healing properties come drawbacks as well. Infrared radiation can penetrate the skin and produce harmful oxidative stress. It also acts synergistically with ultraviolet radiation, further increasing the signs of photoaging.
Main skin concern: Amplifying the signs of skin aging
Where does exposure happen? Indoors and outdoors
Extra credit: Did you know that working in high-temperature environments can actually make you appear older? Extreme temperatures (via infrared radiation A) have been shown to increase the appearance of skin aging. And temperature is just one of the exposome factors that affect the way your skin looks.
How can I protect myself?
Knowledge is power! Solar radiation plays a positive role in our day-to-day lives, but uncontrolled exposure can pose health risks. Understanding the effects of different types of solar and UV radiation can help you make smart decisions about daily sun protection. Discover our line of high SPF, broad spectrum sunscreens.
GW Lambert, C Reid, DM Kaye, GL Jennings, MD Esler, Effect of sunlight and season on serotonin turnover in the brain, The Lancet, Volume 360, Issue 9348, 2002, Pages 1840-1842 Jean Krutmann, Anne Bouloc, Gabrielle Sore, Bruno A. Bernard, Thierry Passeron, The skin aging exposome, Journal of Dermatological Science, Volume 85, Issue 3, 2017,Pages 152-161 Duteil L, Queille-Roussel C, Lacour JP, Montaudie H, Passeron T. Short-term exposure to blue light emitted by electronic devices does not worsen melasma. Journal of the American Academy of Dermatology 2019. Khmaladze I, Leonardi M, Fabre S, Messaraa C, Mavon A. The Skin Interactome: A Holistic "Genome-Microbiome-Exposome" Approach to Understand and Modulate Skin Health and Aging. Clin Cosmet Investig Dermatol. 2020;13:1021-1040. Published 2020 Dec 24.