Download ENVIRONMENTAL HEALTH NOTE/TEA SUNSCREEN

ENVIRONMENTAL HEALTH NOTE/TEA SUNSCREEN
CURWOOD: Coming up: while almost no one was looking, Florida
got stuck with what could become a massive pollution disaster. First,
this Note on Environmental Health from Diane Toomey.
[MUSIC: HEALH NOTE THEME]
TOOMEY: Researchers from Rutgers University, working with
scientists from the University of Minnesota, have found that substances
in tea may help prevent skin cancer. Polyphenols, natural chemicals
found in black and green tea, don’t block UV light, but it’s been found
they can inhibit the process that turns a healthy cell into a cancerous
one.
Researchers swabbed a group of mice with a solution containing
polyphenols. Another group was left untreated. Then they shined UVB
light, the ultraviolet light that causes skin cancer, on the shaven backs
of all the mice.
UV light activates certain proteins that signal cells to divide and
multiply. If cells multiply too fast or too long, cancer could result. The
researchers found that the polyphenols inhibited the activity of these
proteins, compared to proteins in the mice not treated with them. They
also found the same effect when they applied the solution to cultured
human skin cells.
The researchers presented their work at the meeting of the American
Chemical Society and say they're in the early stage of developing a
polyphenol-based cream that could supplement sunscreens currently in
use.
That's this week's Health Note. I’m Diane Toomey.
CURWOOD: And you're listening to Living on Earth.
[MUSIC: Terence Blanchard “Title Theme” 25th HOUR (Hollywood
Records-2003)]
Vocabulary
Polyphenol pä-lE-'fE-"nOl, -fi-': noun : a polyhydroxy phenol
- poly·phe·no·lic -fi-'nO-lik, -'nä-/ adjective
phenol 'fE-"nOl, (n) 1 : a corrosive poisonous crystalline acidic compound
C6H5OH present in coal tar and wood tar that in dilute solution is used as a
disinfectant『化學』石炭酸
phenol red : a red crystalline compound C19H14O5S used especially as an
acid-base indicator (ref: litmus paper 石蕊試紙 a coloring matter from
lichens that turns red in acid solutions and blue in alkaline solutions and is
used as an acid-base indicator
hydroxy (adj) being or containing hydroxyl; especially : containing
hydroxyl especially in place of hydrogen -- usually used in combination
<hydroxyacetic acid> 『化學』氫氧根的 (hydroxyl : the chemical group
or ion OH that consists of one atom of hydrogen and one of oxygen and is
neutral or negatively charged)
swab (vt) swabbed; swabbing 1 : to clean with or as if with a swab 2 : to
apply medication to with a swab <swabbed the wound with iodine>
swab (n) 1 a : MOP; especially : a yarn mop b (1) : a wad of absorbent
material usually wound around one end of a small stick and used for
applying medication or for removing material from an area (2) : a specimen
taken with a swab c : a sponge or cloth patch attached to a long handle and
used to clean the bore of a firearm
sunscreen 1 : a screen to protect against sun 2 : a substance (as paraaminobenzoic acid) used in suntan preparations to protect the skin from the
deleterious effects of sunlight and especially from ultraviolet radiation
aminobenzoic acid &-"mE-nO-ben-'zO-ik-: any of three crystalline
derivatives C7H7NO2 of benzoic acid; especially : Para-Aminobenzoic
Acid : "par-&-&-"mE-"nO-"ben-'zO-ik-,: noun : a colorless para-substituted
aminobenzoic acid that is a growth factor of the vitamin B complex -- called
also PABA
deleterious "de-l&-'ti-rE-&s adjective: harmful often in a subtle or
unexpected way <deleterious effects> <deleterious to health> synonym see
PERNICIOUS
Discussion Questions
1. Did you ever get sunburn? Describe your experience to us.
Where did it take place? During noon time?
2. There are fluorescent UV devices that can give people tan.
Would you use it to show that you have tan and in other words,
healthy? Why not? If you don’t use it, how would you talk to a
Caucasian friend, who insists on buying one to get tan?
3. We just learned that tea applied on the skin can suppress
cancerous skin cell development. But, the polyphenol does not
absorb UV, while sunscreen does. What do you think of a
product which is a combination of the two? So if you are
designing a new product, what would be percentage of ?
4. How would you market such a product? How much price
increase (in %) over the purely PABA-based sunscreen would
you ask for as a manufacturer?
5. Ladies in Taiwan use umbrellas to block sunlight, generally for
the sake of keeping fair skin. What do you think about the
sunlight reflected from white concrete surfaces of roads or walls?
How strong is the UV in such reflection? Do you have creative
ways (such as a new umbrella design) to give more protection?
Ultraviolet Index: What You Need to
Know
Source: American Academy of Dermatology
Did you know that overexposure to the sun can cause skin and eye injury? While some
sunlight is necessary, too much is dangerous, causing sunburn, premature aging of the skin,
skin cancer, cataracts, allergies, and damage to the immune system. Though the average
person gets 50% of his or her lifetime sun by the age of 18, everyone needs to be aware of
the dangers of exposure to sunlight.
The ill effects of sunlight are caused by ultraviolet (UV) radiation. These invisible rays from the
sun come in two types, called UVA and UVB, both of which cause sun-related skin damage.
Solar radiation, and ultraviolet (UV) light in particular, is increasing worldwide with the
thinning of the protective ozone layer. Over 90% of ultraviolet radiation is UVA, which is most
intense in early morning and afternoon, can pass through window glass, penetrates into the
dermis, and causes tanning and wrinkling. UVB is most pronounced midday, does not
penetrate window glass, and is associated with sunburn. Ultraviolet light has been implicated
in multiple human diseases from skin cancer to cataracts to immune suppression.
WHAT IS THE UV INDEX?
To help people gauge sunlight exposure during outdoor activities and avoid overexposure to
the damaging rays of the sun, the National Weather Service (NWS) and the Environmental
Protection Agency (EPA) developed the UV Index. The index is issued daily and predicts the
next day's amount of exposure to UV rays on a 0–10+ scale:
Index Number Exposure Level
0–2
Minimal
3–4
Low
5–6
Moderate
7–9
High
10+
Very High
Always take precautions against overexposure, and take special care whenever the UV Index
is 5 and above.
HOW MUCH SUN AM I GETTING?
Though the amount of UV radiation to which you are exposed varies with the time of day,
season, latitude, and altitude, it can also be increased depending on your immediate
environment. Clouds actually provide little protection from UV rays, and clouds, water, white
sand, concrete, and snow all reflect UV rays and increase exposure. Of course, exposure to the
midday sun or for long periods of time is most damaging.
WHAT ROLE DOES OZONE-LAYER DEPLETION PLAY?
The ozone layer shields the earth from the sun's harmful UV rays. Over the past ten years,
scientists worldwide have recorded decreasing levels of ozone in the atmosphere. Less ozone
means that more UV radiation reaches earth, increasing the danger of sun damage. The cause
of the ozone depletion is under debate, but scientists agree that future levels of ozone will
depend upon a combination of natural and man-made factors, including the phase-out of
chlorofluorocarbons and other ozone-depleting chemicals.
EFFECTS OF SUN
Sunburn. Overexposure to the sun can happen in just a few hours. A bad reaction includes
tenderness, pain, swelling, and blistering, and may include fever, chills, and nausea. While
there is no cure for sunburn, wet compresses, cool tub baths, and soothing lotions may help.
If you have a bad burn, see your dermatologist.
Tanning. Some people think that a tan means good health and looks. Dermatologists know
that a tan does not prevent sun damage, it is sun damage. Tanning occurs when the UV rays
penetrate the skin and injure the pigment cells. The effects are cumulative, and with every
burn, the skin becomes more damaged.
Premature wrinkling. People who work or lay in the sun without sufficient protection get
sagging cheeks and deep wrinkles that may make them look much older. The sun can also
cause unsightly red, yellow, gray, or brown spots and scaly growths that may develop into
skin cancer.
Skin cancer. Skin cancer is caused by too much sun, both long-term exposure and bad
sunburns. More than 90 percent of all skin cancers occur on parts of the body exposed to the
sun. The face, neck, ears, forearms, and hands are the most common places for skin cancer to
develop.
The three main types of skin cancer are basal cell, squamous cell, and melanoma.
Basal cell carcinoma usually appears as a small, shiny, fleshy nodule on the exposed parts of
the body. It grows slowly and rarely spreads to other parts of the body; but it can severely
damage skin around and below it. When diagnosed and treated early, it has a high cure rate.
Squamous cell carcinoma typically develops on the face, ears, lips, and mouth, beginning as a
red scaly patch. It also has a high cure rate when detected and treated early but left untreated,
squamous cell carcinoma can spread to other areas of the body and can be fatal.
Melanoma is the most dangerous form of skin cancer and usually appears as a dark brown or
black lump with irregular edges. Sometimes, it is multicolored with shades of red, blue, or
white. If ignored, melanoma can spread or metastasize to other areas of the body, which can
be fatal.
Eye damage. The sun can cause cataracts and other eye damage. Cataracts are one of the
leading causes of blindness.
Immune system suppression and disease. Short periods of sun exposure can damage the
human immune system and make the body more susceptible to infections and cancers. Also,
some diseases can become worse with sun exposure. These include herpes simplex (cold
sores), chicken pox, lupus, and certain genetic problems.
WHAT ARE PROPER PRECAUTIONS?
Preventing skin cancer and eye damage. Skin cancer is increasing faster than any other
form of cancer, with over 1 million new cases predicted to occur in the U.S. this year.
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Listen to the UV Index reports.
Minimize sun exposure at midday (10:00 a.m. to 4:00 p.m.)
Avoid sunlamps, tanning beds and tanning parlors.
Apply a broad-spectrum sunscreen with Sun Protection Factor-15 or higher and
reapply every 2 hours.
Wear protective, tightly-woven clothing, a broad-brimmed hat and sunglasses.
Children who will not wear sunglasses should wear a hat with a wide brim.
Protect children by keeping them indoors between 10:00 a.m. and 4:00 p.m., and
by applying sunscreen to children older than 6 months. Children under the age of
6 months should be kept out of the sun.
NEED MORE INFORMATION?
For more information on the UV Index, please call the EPA Stratospheric Ozone Hotline,
800-296-1996, or the National Weather Service, 301-713-0622.
SPF
sun protection factor: the effectiveness of suntanning preparations in protecting the skin from
the harmful effects of the sun's ultraviolet radiation, as rated on a scale of increasing
protectiveness from 2 to 15 or sometimes higher.
The sun hits our skin with Ultra violet rays whenever we are outside. The sun's rays that reach
the earth, range from 290nm inthe midultraviolet light range (UV-B) through the visible and
infrared spectra and beyond. The best sunscreen would be to avoid these, ideally at least
between the hours of 10am and 3pm.Covering up and using umbrellas also helps. Since these
are ideal and not always realistic or a reality for many of us the next best thing woudl be to
use sunscreen. Sunscreen protects us from the harmful rays of the sun. By protecting ourselves
from the sun, we are protecting ourselves from skin diseases such as skin cancer. The type of
sunscreen ranges as do our skin types. There are those of us who have darker skin which takes
longer tan and those of us with fair skin who burn fairly easily. There are 6 skin types. Type 1
always burns, never tans. Very fair skin w/ red or blond hair and feckles. Type 2- burns easily ,
tans minimally. Type 3 sometimes burns and gradually tans. Type 4 has minimun burning,
always tans, has white to medium pigmentation. Type 5 seldom burns, always tans. Medium
to heavy pigmentation. Type 6 Never burns, but tans very darkly. these different types take
different amounts of time to burn or tan, as you might have noticed the darker the person,
ususally the slower the process, and therefore can endure greater amounts of time in the sun.
What is called our "natural " protection usually starts off lasting about 15 min. and if this is
the case for you then you would want to get a SPF15 and then if your skin is a little more
sensitive you would want to purchase a higher number because it has a higher protection.
What sunscreen does is protect you from UVA and UVB rays. The ozone usually blocks these
to some extent however, the as the ozone depletes away so does our protection andtat is why it
is more important thatn ever to to protect ourselves by which ever means necessary, sunscreen
is amongst the best and most convenient methods of doing so.
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There is something mysterious about the sun and skin. Why is it that if you go out
on a bright summer day and spend an hour in the sun, you get a sunburn? You
get a sunburn, that is, unless you happen to have taken the time to get a nice
gradual tan. With a nice tan you can go out in the sun and nothing happens. Of
course, that doesn't apply if you have "fair skin". The fair skinned among us
never get a tan, so they always get sunburned. Unless of course they are
wearing a sunscreen...
Does this make sense??? What the heck is a sunscreen? And what is a tan?
What is the difference between a tan and a burn? Why can you spread a little
blob of lotion on yourself and be protected, but if you forget you are miserable?
If you take the time to look at skin and sunlight in some detail, all of this actually
does begin to make sense. You can learn a huge amount about your body in the
process. So, that's what we'll do in this article. First, let's take a look at how skin
works.
HOW SUNSCREENS WORK?
Sunscreens block or absorb ultraviolet light. You can block UV with opaque
creams like the white zinc oxide cream that you see lifeguards putting on their
noses. You can also absorb UV radiation in much the same way that melanin
does. The first and most common of the absorption chemicals is PABA (paraaminobenzoic acid). It absorbs UVB. If you have sensitive skin, take care when
using sunscreen with PABA as it may cause irritation or an allergic reaction in
some individuals. Other sunscreen chemicals include:
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Cinnamates absorb UVB.
Benzophenones absorb UVA.
Anthranilates absorb UVA and UVB.
All sunscreens are labeled with an SPF, or Sun Protection Factor. The SPF acts
like a multiplying factor. If you would normally be OK in the sun for 10 minutes
and you apply an SPF 10 sunscreen, you will be OK in the sun for 100 minutes.
In order for the sunscreen to work, however, you have to apply plenty and it has
to stay on. You should apply it about half an hour before going out in the sun (or
the water) so it can bind to your skin - if you don't, then it is very easy for the
sunscreen to wash off.
The SPF rating, by the way, applies only to UVB radiation.
There is something about this whole discussion that is fascinating. On your body
is an organ - the skin - and it responds in all of these interesting ways to sunlight.