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The following information provided
by the National Center for Chronic Disease Prevention and Health
Promotion and provided on this website as a courtesy to readers.
The South Florida Entertainment Resource and FloridaStuff does not
distribute medical advice and does not claim responsiblity for the content
of this information. Additional links on this page may take you
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Sun Exposure: Questions &
Answers
The best sunscreens protect against both UVB (ultraviolet radiation with wavelength between 290 and 320 nanometres), which can cause sunburn, and UVA (between 320 and 400 nanometres), which damages the skin with more long-term effects, such as premature skin aging. Most sunscreens work by containing either an organic chemical compound that absorbs ultraviolet light (such as oxybenzone) or an opaque material that reflects light (such as titanium dioxide, zinc oxide), or a combination of both. Typically, absorptive materials are referred to as chemical blocks, whereas opaque materials are mineral or physical blocks.
Q: When do I need
to protect myself from sun exposure?
A: Protection from sun exposure is important
all year round, not just during the summer or at the beach. Any
time the sun's ultraviolet (UV) rays are able to reach the earth,
you need to protect yourself from excessive sun exposure. UV rays
can cause skin damage during any season or temperature.
Relatively speaking, the hours between 10 a.m.
and 4 p.m. during daylight savings time (9 a.m. - 3 p.m. during
standard time) are the most hazardous for UV exposure in the continental
United States. UV radiation is the greatest during the late spring
and early summer in North America.
Remember: UV rays reach you on cloudy and hazy
days, as well as on bright and sunny days. UV rays will also reflect
off any surface like water, cement, sand, and snow.
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UV Rays
Q: What exactly are "ultraviolet
rays" ?
A: Ultraviolet (UV) rays are a part
of sunlight that is an invisible form of radiation. UV rays can
penetrate and change the structure of skin cells.
There are three types of UV rays: ultraviolet
A (UVA), ultraviolet B (UVB), and ultraviolet C (UVC). UVA is the
most abundant source of solar radiation at the earth's surface and
penetrates beyond the top layer of human skin. Scientists believe
that UVA radiation can cause damage to connective tissue and increase
a person's risk for developing skin cancer.
UVB rays are less abundant at the earth's surface
than UVA because a significant portion of UVB rays is absorbed by
the ozone layer. UVB rays penetrate less deeply into the skin than
do UVA rays, but also can be damaging.
UVC radiation is extremely hazardous to skin,
but it is completely absorbed by the stratospheric ozone layer and
does not reach the surface of the earth.
Q: How can I protect myself
from the sun's UV rays?
A: When possible, avoid outdoor activities
during midday, when the sun's rays are strongest. This usually means
the hours between 10 a.m. and 4 p.m. You can also wear protective
clothing, such as a wide-brimmed hat, long-sleeved shirt, and long
pants.
For eye protection, wear wraparound sunglasses
that provide 100 percent UV ray protection. And always wear a broad-spectrum
(protection against both UVA and UVB rays) sunscreen and lipscreen
with at least SPF 15. Remember to reapply as indicated by the manufacturer's
directions.
Also, check the sunscreen's expiration date.
Sunscreen without an expiration date has a shelf life of no more
than three years. Exposure to extreme temperatures can shorten the
expiration date or shelf life of sunscreen.
Q: What can excessive
exposure to UV rays do to my health?
A: UV exposure appears to be the most
important environmental factor in the development of skin cancer
and a primary factor in the development of lip cancer.
Although getting some sun exposure can yield
a few positive benefits, excessive and unprotected exposure to the
sun can result in premature aging and undesirable changes in skin
texture. Such exposure has been associated with various types of
skin cancer, including melanoma, one of the most serious and deadly
forms.
UV rays also have been found to be associated
with various eye conditions, such as cataracts.
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UV Index
Q: What
is the UV Index?
A: The UV Index was developed by the
National Weather Service and the Environmental Protection Agency.
It provides a forecast of the expected risk of overexposure to UV
rays and indicates the degree of caution you should take when working,
playing, or exercising outdoors.
The UV Index predicts exposure levels on a
0-10+ scale, where 0 indicates a low risk of overexposure and 10+
means a very high risk of overexposure. Calculated on a next-day
basis for dozens of cities across the U.S., the UV Index takes into
account clouds and other local conditions that affect the amount
of UV radiation reaching the ground.
The level of danger calculated for the basic
categories of the index are for a person with Type II skin. For
a person with type II skin, for example, an Index value of 5 or
6 represents a moderate possibility of UV overexposure.
More information about the UV Index is available
at the EPA Web site: http://www.epa.gov/sunwise/uvindex.html.
You can also call the Environmental Protection Agency (EPA) hotline
at 1-800-296-1996 for more information on the UV Index.
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Tanning and Burning
Q: What does a suntan indicate?
Why does the skin tan when exposed to the sun?
A: The penetration of UV rays to the
skin's inner layer results in the production of more melanin. That
melanin eventually moves toward the outer layers of the skin and
becomes visible as a tan.
A suntan is not an indicator of good health.
Some physicians consider the skin's tanning a response to injury
because it appears after the sun's UV rays have killed some cells
and damaged others.
Q: Not everyone burns or
tans in the same manner. Are there ways to classify different skin
types?
A: Whether individuals burn or tan depends
on a number of factors, including their skin type, the time of year,
and the amount of sun exposure they have received recently. The
skin's susceptibility to burning can be classified on a five-point
scale as outlined in the following table:
| Skin
Type |
Tanning and Sunburning
History |
| I |
Always burns,
never tans, sensitive to sun exposure |
| II |
Burns easily,
tans minimally |
| III |
Burns moderately,
tans gradually to light brown |
| IV |
Burns minimally,
always tans well to moderately brown |
| V |
Rarely burns,
tans profusely to dark |
| VI |
Never burns,
deeply pigmented, least sensitive |
Though everyone is at risk for damage as a
result of excessive sun exposure, people with skin types I and II
are at the highest risk.
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Rub It On
Q: Does it matter
what kind of sunscreen I use?
A: Sunscreens come in a variety of forms
such as lotions, gels, and sprays, so there are plenty of different
options. There are also sunscreens made for specific purposes, such
as the scalp, sensitive skin, and for use on babies. Regardless
of the type of sunscreen you choose, be sure that you use one that
blocks both UVA and UVB rays and that it offers at least SPF 15.
Q: What does a sunscreen's
SPF rating mean?
A: Sunscreens are assigned a Sun Protection
Factor (SPF) number according to their effectiveness in offering
protection from UV rays. Higher numbers indicate more protection.
As a rule of thumb, you should always use a sunscreen with at least
SPF 15.
Q: Do sunscreens need
to be reapplied during the course of a day?
A: You should follow the manufacturer's
directions regarding reapplication or you risk not getting the protection
that you might think you are getting. Though recently developed
sunscreens are more resistant to loss through sweating and getting
wet than previous sunscreens were, you should still reapply frequently,
especially during peak sun hours or after swimming or sweating.
Q: How do sunscreens
work?
A: Most sun protection products work by absorbing,
reflecting, or scattering the sun's rays. Such products contain
chemicals that interact with the skin to protect it from UV rays.
Sunscreens help prevent problems related to sun exposure, such as
aging skin and precancerous growths.
Keep in mind that sunscreen is not meant to
allow you to spend more time in the sun than you would otherwise.
That's why it is important to complement sunscreen use with other
sun protection options: cover up, wear a hat and sunglasses, and
seek shade.
Q: Some cosmetic
products claim to protect you from UV rays. Can they?
A: There are cosmetics and lip protectors
that contain some of the same protective chemicals used by sunscreens
on the market. However, not all of these products meet the standard
of having at least SPF 15, and therefore do not offer sufficient
protection by themselves.
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Cover up
Q: What kinds of clothing
best protect my skin from UV rays?
A: Clothing that covers your skin protects
against the sun's UV rays. Loose-fitting long-sleeved shirts and
long pants made from tightly woven fabric offer the best protection.
A wet t-shirt offers you much less UV protection than does a dry
one.
If wearing this type of clothing isn't practical,
at least try to wear a t-shirt or a beach cover-up. Keep in mind,
however, that a typical t-shirt actually has an SPF rating substantially
lower than the recommended SPF 15, so double-up on protection by
using sunscreen with at least SPF 15 (and UVA and UVB protection)
and staying in the shade when you can.
Q: Does protective clothing
have to be a certain color?
A: Wearing clothing made of tightly-woven
fabric is best for protecting your skin, regardless of the color.
Darker colors, though, may offer more protection than lighter colors.
Q: It gets so hot here
in the summer, there's no way I could be comfortable in long pants
and a long-sleeved shirt. So, what else can I do to protect my skin?
A: Protecting yourself from the sun's
UV rays doesn't have to be a major chore; it's just a matter of
knowing your options and using them. Wearing a dry t-shirt is a
good start, but it is not enough if you are going to be outside
for more than a few minutes.
If you can't wear long pants and a long-sleeved
shirt, you can boost your protection by seeking shade whenever possible
and by always wearing sunscreen with at least SPF 15.
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Get a Hat
Q: Will a hat help protect
my skin? Are there recommended styles for the best protection?
A: Hats can help shield your skin from
the sun's UV rays. Choose a hat that provides shade for all of your
head and neck. For the most protection, wear a hat with a brim all
the way around that shades your face, ears, and the back of your
neck.
If you choose to wear a baseball cap, you should
also protect your ears and the back of your neck by wearing clothing
that covers those areas, using sunscreen with at least SPF 15, or
by staying in the shade.
Q: For the best protection,
what material should I look for in a hat?
A: A tightly woven fabric, such as canvas,
works best to protect your skin from UV rays. When possible, avoid
straw hats with holes that let sunlight through.
Q: Does the color of my
hat matter?
A: The amount of shade offered by a
particular hat appears to be its most important prevention characteristic.
If a darker hat is an option, though, it may offer even more UV
protection.
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Grab Shades
Q: Are sunglasses an important
part of my sun protection plan?
A: Yes. Sunglasses protect your eyes
from UV rays and reduce the risk of cataracts. They also protect
the tender skin around your eyes from sun exposure.
Q: What type of sunglasses
best protects my eyes from UV rays?
A: Sunglasses that block both UVA and
UVB rays offer the best protection. The majority of sunglasses sold
in the United States, regardless of cost, meet this standard. Wrap-around
sunglasses work best because they block UV rays from sneaking in
from the side.
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Seek Shade
Q: Is there any particular
time I should try to stay in the shade?
A: The sun's UV rays are strongest and
do the most damage during midday, so it's best to avoid direct exposure
between 10:00 a.m. and 4:00 p.m. You can reduce your risk of skin
damage and skin cancer by seeking shade under an umbrella, tree,
or other shelter before you need relief from the sun.
Q: I work outdoors all summer
and can't stay in the shade. What can I do to protect my skin?
A: If you can't avoid the sun, you can
protect your skin by wearing a wide-brimmed hat, wraparound sunglasses
that block both UVA and UVB rays, long-sleeved shirt, and long pants.
You can also wear a sunscreen and lipscreen with at least SPF 15
and UVA and UVB protection and reapply according to the manufacturer's
directions. When you can, take your breaks and your lunch in the
shade.
Q: If I stay in the shade,
should I still use sunscreen and wear a hat?
A: UV rays can reflect off virtually
any surface (including sand, snow and concrete) and can reach you
in the shade. Your best bet to protect your skin and lips is to
use sunscreen or wear protective clothing when you're outside ---
even when you're in the shade.
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