Summer Sun Protection - Part 1: What Are We Protecting Ourselves From?
Summer is our favorite season at Alder New York. We love drinking margaritas, laying on the beach, and the occasional Summer Friday. But with all the fun that longer days and warmer weather have to offer, there's also a new factor that we typically don't have to think about in the cooler months: sun exposure. That's why we've started our new series, SUMMER SUN PROTECTION, a multi-part essay diving into why and how to protect yourself while enjoying the summer sun.
It's common knowledge that the sun's rays can be harmful to our health, but do we really know what we're protecting ourselves from? The sun emits more than the visible light that we perceive as "sunlight." The sun's rays are made up of visible light but also invisible Infrared and Ultra Violet light. Our eyes can only detect a small portion of the electromagnetic spectrum. Infrared light and Ultra Violet radiation exist on either side of the portion of the spectrum we can see. The part that we're protecting ourselves from overexposure to is the Ultra Violet section.
Ultra Violet Rays (UVR) are the shorter waves that exist past violet on the spectrum of color we can see. They are responsible for sunburns, wrinkles, cataracts, skin cancers, as well as increased risk of infection and limiting the efficiency of vaccinations. Despite UV rays making up only a small portion of the radiation the sun emits, UV rays are the most damaging rays emitted by the sun.
UVR can be broken down into 3 different types based on the size of their wavelengths. The 3 types, starting with the longest wavelength, are UVA, followed by UVB and UVC. UVC rays are blocked by the ozone layer and typically don't make it to the earth’s surface.
UVA & UVB
UVA rays are most consistently emitted by the sun and are capable of penetrating glass and clouds, making them the most prevalent form of Ultra Violet radiation we're exposed to. These rays are the ones that are responsible for making our skin look tan: our skin cells' reaction to stopping UVA rays from further damaging our DNA. Wrinkles and premature skin aging are also accredited to UVA rays. This form of radiation damages skin cells in the layer of skin where most skin cancers occur.
UVB rays cause sunburns and skin redness. They don't penetrate as deeply as UVA rays, damaging mostly the superficial layer of our skin, the epidermis. These rays' intensity depends on season, time of day, and location. In the US they are the most intense during the late spring months through early fall, between 10AM and 4PM, and in regions near the equator.
THE NEGATIVE HEALTH EFFECTS OF UV RADIATION
"Between 2 and 3 million non-melanoma skin cancers, e.g. basal cell carcinomas and squamous cell carcinomas, are diagnosed each year" says the World Health Organization. Exposure to UV radiation is credited as a factor in the development of these types of skin cancers especially in fair-skinned people, and the number of people diagnosed keeps going up. "Between the 1960s and the 1980s the prevalence of non-melanoma skin cancers increased by a factor of more than two." Non-melanoma cancers like SSC and BCC are easily treatable by surgery but can leave disfiguring marks and can be painful.
In recent years, more evidence has been collected linking melanoma skin cancers (the more deadly from of skin cancer) to UV exposure. Previously it was believed that only non-melanoma cancers were caused by UV radiation, about 90% of all cases, but after studying the genome of Melanoma and regular skin, there is strong evidence that melanomas are effected by both genetics and Ultra Violet radiation exposure.
While the increase in the likeliness of developing skin cancer mostly effects people with fair skin, the risk of UV radiation-related health effects on the eye and immune system is independent of skin type. Years of chronic UV exposure increases the risk of cataracts, a clouding of the eye lens by a process called oxidative stress. Additionally "UV radiation may suppress cell-mediated immunity and thereby enhance the risk of infectious diseases and limit the efficacy of vaccinations," according to the WHO. These immunity and eye health issues are universally a problem no matter skin color.
HOW MUCH IS TOO MUCH?
Determining what is "overexposure"is difficult. The safe amount of UVR that one should be exposed to is dependent on a number of factors that changes from person to person, making it difficult to determine a rule or blanket regulation for safe UV exposure. As of now, the FDA recommends staying out of the sun between the hours of 10AM and 2PM when UV rays are their strongest, wearing protective clothing, and applying a sunscreen with a broad spectrum SPF of 15 or more.
Check the ANY blog in the coming weeks for an in in-depth dive into sunscreen in the next installment in our Summer Sun Protection series.