Exposure to sunlight is exposure to electromagnetic radiation, made up of visible, ultraviolet and infrared light. Our skin is chiefly affected by UV radiation.
There are 3 kinds of ultraviolet light, UVA, UVB and UVC rays. The latter of those being the more powerful and thankfully obstructed by the stratosphere, except in those areas where the ozone layer has diminished. Some professional mountain climbers might actually be in danger of these rays. The wavelengths of UVA and UVB however do penetrate into our skin at varying levels, with the chemical and biological effects being greater than simple heating.
The skin’s relationship with the sun is odd as it is absolutely required for the healthy formation of Vitamin D, which exclusively comes from UVB rays. However this process takes an approximation of 20 minutes, before UVA rays actually begins to destroy the creation. Vitamin D is responsible for preventing numerous conditions such as rickets and osteoporosis which affect our bones. It supports our immune system and some research suggests it plays a crucial role in treating depression as well as some cancers.
UVA rays are the more insidious kind as they create barely any visible signs of damage or redness and are equated as the rays responsible for ageing. Their longer wavelengths are 500-800 times weaker than UVB but 1000 times greater in numbers, while being poorly absorbed by the ozone layer. They penetrate as deep as the dermis; the deeper structure of the skin that contains significant components for a healthy skin. The damage is cumulative and becomes more visible over time as either pigmentation, wrinkling or sagging etc.
When we experience a sunburn, we observe the effects of UVB on the skin which are the main cause for burning. They penetrate as far as the epidermis, the outermost layer of the skin, creating swelling, redness and even blistering. In some cases for those who experience yearly sunburns they may actually be at a higher risk for skin cancer. The wavelengths are shorter, 500-800 times stronger than UVA rays but thankfully 1000 times less numerous.
I believe it is relevant to note the effects of infra-red light on our skin as it is far more prevalent than UV and penetrates deeply. They may cause epidermal atrophy, pigmentation, cell degeneration as well as dermal elastosis. Investigations have advised that darker skins may need extra protection from these rays, as melanin can have toxic properties after exposure.
The damage incurred from ultraviolet light only accumulates over time and does not diminish, this is mainly due to our almost unavoidable daily exposure. The more unsettling of the wide-ranging harmful effects is the depletion of our langerhan cells, important for our skin’s immunity. Without them, we become susceptible to dermatological disorders.
Vitamin A; previously defined in this blog as the fundamental weapon against the suppression of ageing, unfortunately is destroyed by both UVA and UVB rays at all levels of the skin’s structure. Ultimately leading to the deterioration of our appearance and well-being. Thankfully there are now complete approaches and products that protect our skin from the sun’s harmful affects while still acquiring its many benefits.