Anti-UV

What Damage Occurs With UV?
The short-term results of unprotected exposure to UV rays are sunburn and tanning. Long-term exposure causes prematurely aged skin, wrinkles, loss of elasticity, dark patches (lentigos, which are sometimes called “age spots” or “liver spots"), and actinic keratoses. And actual skin cancers. Actinic keratoses are small (usually less than 1/4 inch) rough or scaly spots. Usually they develop on the face, ears, back of the hands, and arms of middle-aged or older people with fair skin, although they can arise on other sun-exposed areas of the skin. Although actinic keratoses are slow-growing and usually do not cause any symptoms, they sometimes turn into squamous cell cancer.
The American Cancer Society estimates more than 1 million new cases of highly curable basal and squamous cell cancers will be diagnosed this year. The most serious form of skin cancer is melanoma, which is diagnosed in about 50,000 people each year and causes several thousand deaths. During the 1970s, the incidence rate of melanoma increased rapidly at about 6% per year. Since 1981, however, the rate of increase slowed to about 3% per year.
Besides skin cancer, the sun's UV radiation also increases the risk of cataracts and certain other eye problems, and can suppress the immune system. And although dark-skinned people are generally less likely to get skin cancer than light-skinned people, they are susceptible to cataracts and immune suppression.

Ultraviolet radiation from welding arcs and safety standards:
The present welding processes which are conducted Shielded metal arc welding, carbon dioxide(gas shielded) arc welding, Metal Active Gas(MAG) welding, Metal Inert Gas(MIG) welding, Tungsten Inert Gas(TIG) welding, Self-Shielded arc welding and so on. 3 welding Spectrum Charts using some of these welding processes are shown below. As these charts show,



UV-B and UV-C, which have short wave lengths and usually don't exist in nature, are generated in large quantities. From a long time ago it was taken for granted that workers in such welding work shops would get ophthalmia or skin erythema from exposure to strong Ultraviolet radiation. However, American Conference of GI Hygiene(ACGIH) is advising on the establishment of Threshold Limit Values (TLV) of Ultraviolet radiation which human bodies are exposed to. TLV is a safety standard for workers exposed to Ultraviolet radiation from both artificial and natural light sources, and in order to prevent serious injuries and diseases, it shows the limit of the spectrum range of UV radiation. Wave lengths from 200 to 400 nm, when workers work for 8 hours being repeatedly exposed to UV radiation. As for harmful UV radiation emissions from welding machinery, it is considered that manual welding and semi-automatic welding are riskier than any other welding process because workers have to be much closer to the light source in those 2 processes than in the others.

Are Any UV Rays Safe?
Two main types of UV radiation reach the earth, UVA and UVB. UVB radiation is well known to cause damage to the DNA of skin cells. Skin cancers develop when this damage affects the DNA of genes that control growth and division of skin cells. Recent research has found that UVA also contributes to skin cancer formation. Scientists now believe that both UVA and UVB rays contribute to skin damage, including skin cancer. There are no safe UV rays.

Are Some People More Susceptible To Sun Damage?
Everyone's skin and eyes are susceptible to sun damage. Although people with light skin are more susceptible to sun damage, darker skinned people, including African Americans and Hispanic
 Americans, also can be affected.
People with darker skin tan more easily than others. Tanning occurs when ultraviolet radiation is absorbed by the skin, causing an increase in the activity and number of melanocytes, the cells that produce the pigment melanin. Melanin helps to block out damaging rays up to a point, which is why darker skinned people burn less easily.
Those with lighter skin are more likely to burn. Too much sun exposure in a short period results in sunburn. A sunburn causes skin redness, tenderness, pain, and in some cases, swelling and blistering as well. Symptoms of a more serious sunburn include fever, chills, upset stomach, and confusion. If these symptoms develop, see a doctor. The long-term consequence of sunburn is more serious than these short-term symptoms, however. UV exposure that is intense enough to cause sunburn will clearly increase a person's risk of developing skin cancer. But, UV exposure can increase skin cancer risk even without causing a sunburn.
Extra care should be taken to protect babies and children from the sun. Studies show that intense exposure, including exposures that lead to sunburns, as a child or teenager could increase the risk for melanoma, sometimes a fatal form of skin cancer.

You need to be especially careful in the sun if you:

• have lots of moles, irregular moles, or large moles
• were previously treated for skin cancer?
• work indoors all week and then get a tan on weekends
• live or vacation in tropical or subtropical climates
• have freckles and burn before tanning
• have fair skin; or blond, red, or light brown hair
• have a family history of skin cancer, especially melanoma
• live or vacation at high altitudes (ultraviolet radiation from the sun increases 4% to 5% for every 1,000 feet above sea level)?
• spend a lot of time outdoors
• have had an organ transplant
• have certain diseases, such as lupus erythematosus
• take tetracycline, sulfa drugs and some other antibiotics
• take naproxen sodium and some other nonsteroidal anti-inflammatory drugs
• take phenothiazines (major tranquilizers and anti-nausea drugs)
• take tricyclic antidepressants
• take thiazide diuretics (medications used for high blood pressure and some heart conditions)
• take sulfonylureas (a form of oral anti-diabetic medication)?
• take medications that reduce immunity

Ask your doctor, nurse, or pharmacist about the risk of any medicines you may be taking that could be harmful to you if you are exposed to sunlight.

What Is the UV Index?
To increase awareness of the damaging potential of UV radiation, the Environmental Protection Agency and the National Weather Service developed the UV Index. The UV index number, ranging from 0 to 10+, indicates the amount of UV radiation reaching the earth's surface during an hour around noon. It is forecast daily for 58 cities, based on locally predicted conditions. The higher the number, the greater the exposure to UV radiation. The UV Index is valid only for about a 30-mile radius from the city, and, as with any forecast, local variability in cloud cover and other factors may change actual levels experienced, but it serves as a reminder to take precautions against UV exposure.

How Do I Protect Myself From UV?
It is impossible to completely avoid sunlight and it would be unwise to reduce your level of activity because you don't want to be outdoors. But there are precautions that you can take to limit your amount of exposure to UV.
Some people think about sun protection only when they spend a full day at the beach or pool. But sun exposure adds up day after day, and it happens whenever you are in the sun, for example when you are gardening, fishing, hiking, riding a bike, going to the zoo, attending a baseball game, or going to and from your car. The following are steps that provide a practical approach to protecting yourself from the effects of the sun.

1. Limit direct sun exposure during midday
The intensity of the sun's rays are related to several factors, including closeness to the equator, altitude, season of the year, time of day, cloud cover, and the ozone "hole." Ultraviolet rays are most intense when the sun is high in the sky, during the midday which is usually between the hours of 10 AM and 4 PM. If you are unsure about the sun's intensity, take the shadow test: If your shadow is shorter than you, the sun's rays are the strongest. Plan activities out of the sun during these times. If you must be outdoors, protect your skin.
UV radiation also can pass through water, so don't assume you're safe from UV radiation if you're in the water and feeling cool. Also, be especially careful on the beach and in the snow because sand and snow reflect sunlight and increase the amount of UV radiation you receive.
If you plan to be outdoors, you may want to check the UV Index for your area. The UV Index usually can be found in the local newspaper or on TV and radio news broadcasts. It also may be available through your local phone company and is available on the Internet at the National Weather Service Climate Prediction Center's home page (ww.nnic.noaa.gov/cpc/).

2. Cover up
When in the sun, keep your shirt on! Wear clothing to protect as much skin as possible. Long-sleeved shirts, long pants, or long skirts are the most protective. Dark colors provide more protection than light colors by preventing more UV rays from reaching your skin. A tightly woven fabric provides greater protection than loosely woven clothing. If you can see light through a fabric, UV rays can get through, too. Also, dry fabric is generally more protective than wet fabric.
The ideal sun-protective fabrics are lightweight, comfortable, and protect against exposure even when wet. Currently a few companies in the US manufacture sun-protective clothing. The American Society for Testing and Measurement (www.astm.org) has recently developed standards for manufacture and labeling of sun protective products. These will soon be published but have not yet been released.
Swimsuits for children made from sun protective fabric and designed to cover the child from neck to knees are popular in Australia and are available in some areas of the US. Consumers can ask retailers to carry these products.

3. Wear a hat
A hat with at least a 2 to 3-inch brim all around is ideal because it protects areas often exposed to the sun, such as the neck, ears, eyes, forehead, nose, and scalp. A shade cap (which looks like a baseball cap with about 7 inches of material draping down the sides and back) also is good. These are often sold in sports and outdoor clothing and supply stores.
A baseball cap provides some protection for the front and top of the head but not the back of the neck or the ears, where skin cancers commonly develop.

4. Use a sunscreen with an SPF of 15 or higher
A sunscreen is a product that you apply to the skin for some protection against the sun's ultraviolet rays, although it does not provide total protection. Sunscreens are available as lotions, creams, ointments, gels, and wax sticks.
When selecting a sunscreen product, be sure to read the label before you buy. Sunscreen products labeled "broad-spectrum" protect against UVA and UVB radiation. Some cosmetics, such as some lipsticks, also are considered sunscreen products if they contain sunscreen and their labels state they do.
Experts recommend products with an SPF (Skin Protection Factor) of at least 15. The number of the SPF represents the level of sunburn protection provided by the sunscreen. A SPF 4 blocks out 75% of the burning UV rays while an SPF 15 blocks out 93% of the burning UV rays; an SPF 30 blocks out 97% of the burning UV rays. The FDA is currently reviewing ways to measure how much protection sunscreen products provide in the UVA range.
It is important to remember that sunscreen does not provide total protection. When using an SPF 15 and applying it correctly, you will get the equivalent of 1 minute of burning UV rays each 15 minutes you spend in the sun. So, 8 hours in the sun wearing SPF 15 sunscreen is the same as spending 32 minutes unprotected. Reflective surfaces like water, snow, and sand can actually cause exposure to more UV rays. For high-glare situations, a higher SPF sunscreen or zinc oxide may be used on your nose and lips.
Products labeled "waterproof" provide protection for at least 80 minutes even when swimming or sweating. Products that are "water resistant" may provide protection for only 40 minutes.
Some sunscreen products can irritate some people's skin. Many products claim to be "hypoallergenic" or "dermatologist tested," but the only way to know for sure whether a product will irritate your skin is to apply a small amount to your skin for three days. If your skin does not turn red or become tender and itchy, the product should be okay for you.
Be sure to apply the sunscreen properly. For maximum effectiveness, apply sunscreen 20 to 30 minutes before going outside. Be generous. About one ounce of sunscreen should be used to cover the arms, legs, neck and face of the average adult. Less is needed for a child. For best results, most sunscreens need to be reapplied about every 2 hours.
If swimming or perspiring, don't forget to reapply sunscreen to maintain protection. Remember that sunscreen usually rubs off when you towel yourself dry.
Use sunscreen lip balm.
If you or your child burn easily, be extra careful to cover up, limit exposure, and apply sunscreen. Also, be sure to use sunscreen if you or your child are taking medications that can make the skin more sensitive to the sun.
Use hats, clothing, and shading to protect babies younger than 6 months from the sun. If shade or protective clothing is not available, very small amounts of sunscreen can be used on small areas, such as the face and the back of the hands.
For children 6 months to 2 years, use a sunscreen with at least an SPF 15.

5. Wear sunglasses that block UV rays
Research has shown that long hours in the sun without adequate eye protection increase the chances of developing eye disease. UV-absorbent sunglasses can help protect your eyes from sun damage.
The ideal sunglasses do not have to be expensive, but they should block 99% to 100% of UVA and UVB radiation. Check the label to be sure they do. Some labels may say, "UV absorption up to 400 nm" which is the same as 100% UV absorption. Also, labels that say "special purpose" or "Meets ANSI UV Requirements" mean the glasses block at least 99% of UV rays. Those labeled "cosmetic" block about 70% of the UV rays. It there is no label, don't buy the sunglasses. (The American National Standards Institute ANSI sets standards for sunglasses' UVA/UVB protection. They require that sunglasses block a minimum of 50% of UV.)
Darker glasses are not necessarily better because the UV protection comes from an invisible chemical applied to the lenses, not from the color or darkness of the lenses. Look for an ANSI label.
Ideally, all types of eyewear, including prescription glasses, contact lenses, and intraocular lens implants used in cataract surgery, should absorb the entire UV spectrum. Large-framed wraparound sunglasses protect your eyes from all angles. Children need smaller versions of real, protective adult sunglasses-- not toy sunglasses.

6. Avoid sunlamps and tanning booths
Many people believe that the UV rays of tanning beds are harmless. This is not true. Tanning lamps emit UVA and frequently emit a lot of UVB also. Both UVA and UVB can cause serious skin damage, and both contribute to formation of skin cancers. Because of these dangers, health experts advise people to avoid sunlamps for tanning.
Sunlamp products are regulated by the US Food and Drug Administration (FDA). According to their regulations, sunlamp products must:

• have a timer to limit the amount of exposure a person can receive in one session.
• have a label with recommended exposure position or distance from the sunlamp to reduce the risk of overexposure, even when the timer is set at its maximum limit.
• limit the amount of short-wave UV radiation emitted from the product. come with UV-blocking goggles, which the user should always wear.
• carry a prominent warning about the dangers of overexposure, especially to those who are sensitive to UV radiation.
• provide information on proper use.

　
7. Check Your Skin Regularly
You can improve your chances of finding precancerous skin conditions, such as actinic keratosis -- (a dry, scaly, reddish, and slightly raised lesion) and skin cancer by examining your skin regularly. The earlier you identify signs and see your health care provider, the greater the chances for simple and successful treatment.
The best time to examine your skin is after a shower or bath. Check yourself in a well-lighted room using both a full-length mirror, and a hand-held mirror. Become familiar with your birthmarks, moles and blemishes so that you know what they usually look like and then can easily identify any changes they undergo. Signs to look for are changes in size, texture, shape, and color of blemishes or a sore that does not heal. If you find any changes, see your doctor or health care provider. Also, during regular checkups, ask your doctor to check your skin.