What Are the Effects of Ultraviolet (UV) Exposure?
Exposure to UV rays is linked to a number of harmful health
conditions, including the following:
Skin cancer
Consider the following statistic related to skin cancer:
- More than 1 million cases of non-melanoma skin cancer are
diagnosed in the US each year.
- Most skin cancers appear
after age 50, but skin damage from the sun begins at an early age.
Therefore, protection should start in childhood to prevent skin
cancer later in life.
Premature aging (photoaging)
Sun exposure also causes premature aging of the skin, a condition
called photoaging, which is different than chronological aging.
- People who sunbathe regularly show photoaging early in life -
often before 30 years of age.
- Chronologically-aged skin,
more often, shows changes after age 40 or older.
- Freckling,
fine wrinkling, and dilation of capillaries are often seen early in
the photoaging process.
- Photoaged skin often develops
irregular pigmentation (liver spots) in later years.
- Both
photoaging and chronological aging cause wrinkling and loss of skin
elasticity. However, these changes occur much earlier when skin has
been overexposed to the sun.
Cataracts and other eye disorders
Cataracts, an eye disorder characterized by a change in the
structure of the crystalline lens that causes blurred vision, are a
leading cause of blindness around the world - and excessive UV
exposure is one of the risk factors in the development of cataracts.
In fact, persons who spend more time in the sun may develop cataracts
earlier than others. The American Academy of Ophthalmology now
recommends wearing UV sunglasses and a wide brimmed hat to lessen
exposure to ultraviolet rays.
Corneal sunburn, growths on the outer surface of the eye,
retinal-tissue damage, and other eye diseases are also known, or
suspected, to be related to long-term exposure to UV rays.
Immune system damage
The skin is part of the body's natural defense system. Many
healthcare professionals believe that UV radiation can alter immune
system functions. When UV radiation suppresses immune responses, the
body's ability to fight certain diseases, including skin cancer, is
reduced. It is suspected that overexposure to UV radiation also
interferes with the effectiveness of immunizations given through the skin.
Sunscreens can help
Studies have shown that sunscreens can prevent UV-induced wrinkling.
Animal studies demonstrated that sunscreens with adequate UVA coverage
can prevent sagging and wrinkling due to high-intensity UVA.
If you think you're at risk, make an appointment with one of our
skin cancer experts at the Stanford
Skin Cancer Program.