Protecting yourself from the UV light of
the sun
Most people know that, while a sun tan may be fashionable
and frolicking outside is good fun, too much exposure to the
sun is dangerous. Sunlight contains ultraviolet light that can
cause sun burns, skin cancer, premature skin aging and eye damage.
The best protection is to stay out of sunlight, especially between
10 am to 4 pm, when the sun is the most direct. Beyond that wear
sunscreen and protective clothing helps.
UVC radiation is absorbed by the atmosphere and doesn't reach
us on earth. UVB radiation affects the outer skin and is the
primary cause of sunburns. UVB doesn't go through glass and its
intensity varies depending on the time of day and skin. UVA radiation
causes deeper skin damage, and does not vary in intensity as
much during the day or year. UVA is not filtered by normal glass.
A good sunscreen should have an SPF of at least 15 (the higher
the better) and block both UVA and UVB radiation. SPF is only
a measures UVB. To block both UVA and UVB, a sunscreen should
contain avobenzone, titanium dioxide, or zinc oxide.
Most people do not apply enough sunscreen. Sunscreen should
be applied liberally to all exposed areas. It takes about 15
to 30 minutes for the sunscreen to be properly absorbed before
you can go outside. Applying sunscreen just before leaving for
out doors is incorrect application. Sunscreens should be applied
regularly throughout the day, including after being in direct
sun for a while, if your skin has gotten wet or the sunscreen
has rubbed off such as when toweling. Sunscreen wears out on
its own in sun, so should be reapplied every couple of hours
or so.
If also using moisturizers or creams lotions, the sunscreen
should be applied first. Some insect repellants diminish the
effectiveness of sunscreen lotion, so more sunscreen should be
used in conjunction with insect repellent.
While sunscreen has traditionally been heavy and sticky, there
are modern lotions that are light and clean, not much different
than face moisturizer. Some of these light sunscreens come in
strong UV protection, PSA45 and above.
As UVA shines all throughout the day, even early in the morning
and before sundown, it's not a bad thing to wear some form of
sunscreen all day. Many skin lotions now contain some sunscreen
(read the label).
Proper clothes can add additional protection from the sun.
Wide brim heavy hat will protect the face and neck. Dark, heavy,
long sleeved shirts offer good protection. Jean and leather jackets
offer very strong protection. If you are going to wear something
light, like a T shirt, dark colors offer more protection than
light colors. There are also UV protecting clothes, specifically
design to protect against UV rays.
Sun's UV light can also damage the eyes, so wearing proper
UV protecting sunglasses when spending time in bright sunlight
is important. The glass of regular prescription glasses offers
some protection. However, UVB penetrates glass, so a proper UVA
and UVB protecting sunglasses is important. A good billed cap
can help shade eyes.
In the end, the best protection is zero protection from the
sunlight. However, as it's practically impossible and undesirable
to all people to avoid all sunlight, one should use proper protection,
including limiting exposure during peak sunlight hours, wear
sunscreen and clothes.
Next: Ultraviolet
light in science and industry
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