Energy from the sun is what powers all life processes on Earth, and that same energy brings visible light, heat and ultra-violet radiation, the kind of energy that causes burning, aging skin, wrinkling and skin cancers.
What are UV Rays (And Why Are They Harmful)?
Visible light breaks off into different regions when you see a rainbow. Similarly, the UV radiation spectrum is divided into three regions according to their wavelengths. (The shorter the wavelength, the more harmful the UV radiation.) These wavelengths, in turn, determine the radiation’s biological activity, and their ability to penetrate the skin.
UVC has the shortest of all wavelengths, and therefore, the most damaging of all. But UVC doesn’t even reach the earth’s surface because it is completely absorbed by the atmosphere, particularly the ozone layer. (The thinning of the ozone layer increases the incidence of blindness in fish in ozone-depleted areas.)
UVB is medium-wavelength but cannot penetrate the superficial or outer layer of the skin. However, prolonged exposure to UVB rays results to delayed tanning and burning. While UVB tends to damage only the superficial epidermal layers, it nonetheless affects the development of skin cancers. The atmosphere filters most solar UVB, so while it’s harmful than UVA, it’s not as common.
But unlike UVB, UVA rays penetrate glass, which is why you still need to wear protection even if you were to remain indoors yet within reach of sun’s rays. Like UVB, UVA also contributes to incidence of some skin cancers.
The long-wavelength UVA makes up about 95% of the UV radiation that reaches the Earth’s surface. UVA penetrates the deeper layers of the skin, resulting to immediate tanning, skin ageing and wrinkling. UVA also damages skin cells in the deep layers of the epidermis wherein most skin cancer occur hence, UVA is one of the main contributor that initiates skin cancer development.
Tanning salons produces UVA rays that are 12 times stronger than of normal sun exposure which if done repeatedly accumulates damage in the skin’s DNA and may eventually lead to skin darkening, mutations and skin cancers.
UVA rays are also the main cause of photoaging. If you realize you are looking old after repeated sun exposure, UVA rays are to blame. This is because every time you get a tan, the skin tries to repair itself by darkening, and this process starts a chain of events that leads to changes in the skin’s DNA. Over time, the skin’s ability to heal and renew gets compromised.
How Does Sun Protection Factor Rating Really Work?
Unlike UV rays, sunscreen comes in more than just three SPF varieties: SPF 15, 30, 50 and higher. A sunscreen’s sun protection factor is a measure of how long you can stay under the sun without getting burned, which means that, in theory at least, the higher the SPF, the longer you can stay under the sun protected.
In reality, however, a sunscreen’s SPF begins to plateau beyond SPF 50, as SPF 30 already blocks 97% of UV rays. At SPF 50, a sunscreen blocks 98% of UV rays. SPF higher than that will not block UV rays significantly.
A skin care specialist typically recommends using a broad-spectrum sunscreen with SPF 30. Also look for ingredients that create physical barrier instead. Ingredients such as titanium dioxide, an active ingredient found in Dr. Sylvia’s Oil Free Solar Defense SPF 30, reflect UV rays away from the skin because this inert earth mineral has a high refractive index.
Dr. Sylvia Ramirez is a leading female dermatologist in Singapore who has developed a range of sun protection and skin care products that rejuvenate at the cellular level. The Oil Free Sun Protection SPF 30, along with Sun Screen Spray SPF 29, are just some of the sun protection products available for use on sensitive, acne-prone skin.
Even with high SPF loaded with ingredients that act as physical barrier against the sun, you shouldn’t stay outdoors for long, especially between 10AM to 4PM when the sun’s rays are strongest. You can easily develop sun spots after prolonged exposure, and while these sun spots can easily be treated by Intense Pulsed Light (IPL) Facial in an aesthetic laser clinic, you should seek shade to reduce your risk of skin cancer.
During overcast days, you still need to wear sunscreen because clouds do not filter UVA rays. This is the same reason why still need to wear sunscreen during winter. Snow reflects the sun’s radiation, and you can get easily sunburned just by being in a snowy landscape without any protection on.