all living beings have developed ways to protect themselves from harsh elements. It may be fur, a

shell, feathers, or scales. Human skin protects itself by becoming thicker and darker.

The sun makes us look healthier and feel better. Just imagine what summer outdoors would be without
the sun shining!As we bare our skin to soak up that sunny goodness, let’s take a look at what is really
happening to our skin as we tan.

Our skin has several built-in sun protection mechanisms. When exposed to the sun, the top skin
layer thickens within four weeks to the equivalent of a weak sunsceen, approximately sun protection
factor (SPF) 4. This type of protection takes time to develop and is too weak to completely shield us
from the harmful effects of the sun’s radiation.

Tanning is the skin’s main way of protecting itself. In fact, it’s an alarm signal pulled by our skin.
Ultraviolet (UV) radiation stimulates skin cell melanocytes to produce more melanin pigment. Sun
radiation causes the melanin to combine with oxygen, which creates the actual tan color in the skin.
Melanin protects the body from absorbing an excess of solar radiation, which can be harmful. The
more we expose ourselves to the sun, the more pigment is produced.

Apart from developing a nice golden tint, our skin undergoes less attractive changes. The sun’s
rays damage skin in several different ways. After sun exposure, our skin becomes thicker, drier, less
pliable, and more prone to irritation. On a molecular level, UV radiation from the sun attacks keratin
cells and fibroblasts, triggering a variety of molecular changes that cause a breakdown of collagen in
the skin and a shutdown of new collagen synthesis. With decades of long sun exposure, the skin starts
looking coarse and thick, and deep wrinkles form. In addition, too much exposure to UV radiation
suppresses the body’s immune system, triggering a complex cascade of changes on a cellular level, so
you may develop increased sensitivity to sunlight and even react differently to immunizations.
Scientists from the University of Münster in Germany found that ultraviolet radiation “can function as
a complete carcinogen by inducing ‘UV signature’ DNA mutations and by suppressing protective
cellular antitumoral immune responses.” They found the precise mechanism by which frequent sun
exposure damages skin: first, UV radiation damages skin cells’ DNA, which results in the release of
an immune-suppressing chemical called inter-leukin-10 (Beissert, Loser 2008). Even low levels of
UV (type B) sun radiation can slow down the immune system of the skin for several weeks. This may
explain why people often develop sun allergies and acne while on vacation.

ABCS OF SUN

Ultraviolet radiation from the sun is a form of electromagnetic radiation. It is divided into three types:
UVA, UVB, and UVC.

UVA radiation (320 to 400 nm wavelength) is weaker than UVA and UVC, but it is the most prevalent
type of sun radiation. UVA radiation causes premature aging at a somewhat slower rate than the
others, but this radiation causes melanoma, a very dangerous type of skin cancer. UVA is not blocked
by many conventional sunscreens, but it can be effectively blocked by physical sunscreens and
clothing.

UVB radiation (280 to 320 nm wavelength) has higher energy than UVA waves and is therefore more
damaging and more carcinogenic. UVB rays burn our skin and cause instant damage. They also raise
the risk for nonmelanoma skin cancers.