Educational Spotlight: UV Rays

About UV Rays

Overview

Skin reacts to UV radiation by a change in the melanin content.  Under strong radiation or conditions of slow change, the familiar reddening (“erythema”) occurs, followed by sunburn and soreness. Human racial groups vary by hair color, skin color, eye type and reaction to exposure to UV radiation. There are six recognized skin types as regards the effects of UV.
Skin type, definition & reaction

1. Red or blond hair, blue-green eyes very light shin –> Mostly burns, does not tan
2. Light-medium hair, eyes and skin –> Usually burns, seldom tans
3. Medium hair, medium to dark eyes, medium to olive skin –> Moderately burns, lightly tans
4. Dark hair, eyes dark, olive to light brown skin –> Burns mildly, tans to moderate brown
5. Dark hair, eyes and skin –> Seldom burns, tans to dark brown
6. Dark hair, eyes and very dark skin –> Insensitive, does not burn

How does this range affect you?  The permissible time for exposure to UV radiation on a midsummer day at sea level at or near the equator without using sunscreen ranges from 20 minutes for individuals with Skin Type 2, to 100 minutes for those with Skin Type 4.
The erythemal potential due to exposure to UV radiation is usually referred to in units of Minimum Erythemal Doses (“MED”) caused by the exposure.  One MED is defined as the amount of UV radiation that produces a just noticeable erythema on previously unexposed skin, and is different for the different skin types.
Most people are unaware of the damage that can be caused even after exposure to low intensity UV radiation, because the dose is accumulated during exposure of varying duration at different times in a daily routine.  Usually the first visible sign is the sunburn, which might appear a few hours after the exposure, while skin cancer may appear years later.  This means that the individual becomes aware of the danger after the damage has been done.
Most people do not routinely use sunscreens unless they are on the beach or a trip.  Even then, they usually do not apply the sunscreens periodically, as they should because it gradually dissipates through perspiration and absorption in the skin.
Altitude, latitude, season, air pollution, clouds, and other factors influence the effective UV radiation level. Therefore it is very difficult to give accurate, reliable and timely warnings to the public about the UV radiation levels for specific location and day time.
The only practical means of protection is a personal dosimeter, a device that measures and indicates the amount of radiation absorbed in a given period.
Currently UVSunSense manufactures and sells a personal dosimeter in the form of a wristband for people with skin type 1 and all children regardless of their skin type.  Coming soon will be two additional bands; Bands, one made for skin types 2 & 3 and another for skin types 4 & 5.
As a safety precaution, each band type is calibrated to finish when it has absorbed 1/2 of the Minimum Erythemal Dose (“MED”) of radiation for the particular skin type it was designed for.

UV Measurement:

milliWatts per square meter	Index Value	Exposure Category
<60	Less than 3	Moderate
60 – 150	3 – 6	High
151 – 580	6 – 10	Very High
> 580	Greather than 10	Extreme

When the UV-Index is 3 (“60 milliWatts or less”), a fair skinned person will experience minimal skin redness after one hour in the sun. When the UV-Index is 6 (“150 milliWatts or less”) , a fair skinned person will experience minimal skin redness after 24 minutes in the sun and when the UV-Index is 10, a fair skinned person will experience minimal skin redness after 6 minutes in the sun. UV-Index levels over 7, around 250 milliWatts per square meter are common and will result in a fair skinned person burning after 15 minutes in the sun.
Remember, potential long term health effects from UV radiation do not depend on skin type.

UV Radiation

The sun radiates energy over a broad spectrum of wavelengths. Ultraviolet (“UV”) radiation, which has a shorter wavelength than either visible blue or violet light, is responsible for sunburn and other adverse health effects. Fortunately for life on Earth, our atmosphere’s stratospheric ozone layer shields us from most UV radiation. What gets through the ozone layer, however, can cause the following problems, particularly for people who spend substantial time outdoors:

• Skin cancer
• Cataracts
• Suppression of the immune system
• Premature aging of the skin

Because of these serious health effects, you should limit your exposure to UV radiation and protect yourself when outdoors.

Types of UV Radiation

Scientists classify UV radiation into three types or bands—UVA, UVB, and UVC. The stratospheric ozone layer absorbs some, but not all, of these types of UV radiation:
UVA: Not absorbed by the ozone layer.
UVB: Mostly absorbed by the ozone layer, but some does reach the Earth’s surface.
UVC: Completely absorbed by the ozone layer and oxygen. UVA and UVB that reach the Earth’s surface contribute to the serious health effects listed above.

UV Levels Depend on a Number of Factors:

The level of UV radiation that reaches the Earth’s surface can vary, depending on a variety of factors. Each of the following factors can increase your risk of UV radiation overexposure and its consequent health effects.
Stratospheric Ozone: The ozone layer absorbs most of the sun’s UV rays, but the amount of absorption varies depending on the time of year and other natural phenomena. That absorption also has decreased, as the ozone layer has thinned due to the release of ozone-depleting substances that have been widely used in industry.
Time of Day: The sun is at its highest in the sky around noon. At this time, the sun’s rays have the least distance to travel through the atmosphere and UVB levels are at their highest. In the early morning and late afternoon, the sun’s rays pass through the atmosphere at an angle and their intensity is greatly reduced.
Time of Year: The sun’s angle varies with the seasons, causing the intensity of UV rays to change. UV intensity tends to be highest during the summer months.
Latitude: The sun’s rays are strongest at the equator, where the sun is most directly overhead and UV rays must travel the least distance through the atmosphere. Ozone also is naturally thinner in the tropics compared to the mid- and high-latitudes, so there is less ozone to absorb the UV radiation as it passes through the atmosphere. At higher latitudes the sun is lower in the sky, so UV rays must travel a greater distance through ozone-rich portions of the atmosphere and, in turn, expose those latitudes to less UV radiation.
Altitude: UV intensity increases with altitude because there is less atmosphere to absorb the damaging rays.  Your risk of overexposure increases as you go to higher altitudes.
Weather Conditions: Cloud cover reduces UV levels, but not completely.  Depending on the thickness of the cloud cover, it is possible to burn and increase your risk of long-term skin and eye damage.  You can burn on a cloudy summer day, even if it does not feel very warm.
Reflection: Some surfaces, such as snow, sand, grass, or water can reflect much of the UV radiation that reaches them.  Because of this reflection, UV intensity can be deceptively high even in shaded areas.

Credits

National Association of Physicians for the Environment American Medical Association Wilderness Medical Society American Skin Association American Academy of Dermatology American Academy of Otolaryngology American Academy of Ophthalmology American Academy of Optometry American Society for Head and Neck Surgery American Optometric Association American Society of Plastic and Reconstructive Surgeons Coalition of Patient Advocates for Skin Disease Research Society for Investigative Dermatology Skin Cancer Foundation

Friends of the Earth National Medical Association Lupus Foundation of America, Inc. Ozone Action, Inc. Alliance for Environmental Education Association of University Environmental Health Sciences Centers Prevent Blindness America Save Our Sky North American Association for Environmental Education NAPE National Office for the Protection of Biodiversity (Galveston, TX) National Association 0f County & City Health Officials (NACCHO) Environmental Alliance for Senior Involvement (EASI) Association of State & Territorial Health Organizations (ASTHO)

What causes Skin Cancer?

Skin Cancer Basics

The skin is the body's largest organ and has several important roles, including protecting us from injury, light and infection, and maintaining the body's temperature. Though skin cells are stacked in three layers--the epidermis, the dermis, and the subcutaneous--it is the epidermis that contains three types of cells that may develop into skin cancer.

The top or outermost layer is made of dead cells that contain keratin. Keratin is a hard waxy substance that helps protect the body. Keratinocytes are the cells that make keratin, and can develop into squamous cell carcinoma.

Melanocytes are deeper within the epidermis and secrete a substance called melanin. Melanin is a pigment that gives our skin color and helps protect cells from sun damage. It is produced in response to sun exposure and is the reason fair-skinned individuals will tan. Melanocytes can develop into malignant melanoma.

At the base of the epidermis are the basal cells. All other cells in the epidermis are derived from the basal cells. Basal cells can develop into the most common type of skin cancer, basal cell carcinoma.

Causes of Skin Cancer

Healthy skin cells grow and multiply in a controlled manner. The new cells produced in the inner basal layer are pushed to the outer layer, die, and are eventually sloughed off. Each skin cell contains genetic instructions, called DNA, that dictate how it grows and functions. If the DNA is damaged and the skin cell begins to malfunction, the body is sometimes unable to repair it. Cancer occurs when these damaged cells start growing out of control, and invade their neighboring cells.

What can damage the skin cell's DNA? Exposure to the sun's ultraviolet (UV) light is the number one cause of skin cancer. There are two types of UV light that reach the earth's surface: UVA and UVB. UVB light is responsible for sunburns, affects only the outer skin layer, and has the greatest role in causing skin cancer. It is filtered by glass and its intensity varies throughout the year. UVA light also causes skin damage, has more intensity than UVB, and can reach the skin's deeper layer. It can penetrate through glass, shallow water, clouds and pollution.

Other causes of skin cancer include:

•Use of tanning booths which use high doses of UVA light.

•Immunosuppression from diseases such as HIV, chemotherapy or drugs used in organ transplant patients.

•Exposure to extremely high X-ray or radiation levels.

•Contact with particular chemicals such as arsenic, industrial tars, oils and soot.

How Skin Cancer Spreads to Other Parts of the Body

When cancer spreads from its primary location to a distant part of the body it is called metastasis. Cancer cells travel through the lymphatic or vascular system. The metastatic or secondary tumor is the same type of cancer as the original. For example, if melanoma spread or metastasized from the skin to the brain, the secondary tumor would be made up of abnormal skin cells. The tumor would be located in the brain, but it would not be composed of abnormal brain cells. The secondary tumor would be referred to as metastatic melanoma.

Skin cancer - the facts - Stay Safe in the sun

• Skin cancer often first appears as a change in a mole or a patch of skin.
• The most serious type of skin cancer is a malignant melanoma but other types, known as non-melanomas, are the most common.
• When found early melanomas can be treated quickly and cured.
• The main cause of skin cancer is too much sun and sunburn can double the risk.
• The most common sites for melanoma are the leg in women, the back in men and the face in older people, but they can grow anywhere.
• You may have some moles or dark patches on your skin that are flat or slightly raised. Usually these will remain harmless all your life.
• Show your doctor any moles or patches of normal skin that change in size, shape or color over weeks or months.
• Other signs that need to be checked out include a new growth or sore that won't heal, a spot, mole or sore that itches or hurts or a mole or growth that bleeds, crusts or scabs.

May is Skin Cancer Awareness Month!!

May is Skin Cancer Awareness Month

Baby Banz encourages sun safety while in the sun

With spring here and summer on the way, it means more people will venture outside to play and work. Swimming, planting flowers, mowing the grass, back yard barbecues and other activities take place during the spring and summer months.

While the warmth and sun bring people outside, Baby Banz and the American Cancer Society encourage everyone to take caution and to protect their skin.

May is skin cancer awareness month. It’s a month used to encourage and remind people to take preventive measures while they enjoy various outdoor activities.

Skin cancer is the most common of all cancers. This type of cancer can almost completely be avoided if people would protect their skin and follow simple guidelines when they are outside.

There are more than 1 million skin cancers diagnosed each year in the United States. That’s more than cancers of the prostate, breast, lung, colon, uterus, ovaries and pancreas combined. And the number of skin cancers has been on the rise for the past few decades.

The vast majority of skin cancers are due to unprotected ultraviolet radiation (UV) exposure. Most of this radiation comes from sunlight, but some may come from artificial sources, such as tanning booths. The amount of UV exposure depends on the strength of the light, the length of exposure and whether the skin is protected.

The American Cancer Society encourages people to enjoy the numerous outdoor activities, but they want them to be sun smart and to follow some easy tips to reduce the risk of skin cancer.

Limit Direct Sun Exposure during Midday
UV rays are most intense during the middle of the day, usually between the hours of 10 a.m. and 4 p.m. 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. If you plan to be outdoors, you may want to check the UV Index in the area.

Cover Up
When in the sun, wear clothing to protect as much skin as possible. Clothes provide different levels of protection, depending on many factors. Long-sleeved shirts, long pants, or long skirts are the most protective. Dark colors generally provide more protection than light colors. A tightly woven fabric protects better than loosely woven clothing. Dry fabric is generally more protective than wet fabric. If you can see light through a fabric, UV rays can get through too. Be aware that covering up doesn’t block out all UV rays. A typical light T-shirt worn in the summer usually provides less protection than a sunscreen with a Sun Protection Factor (SPF) of 15 or higher.

Use a Sunscreen with a Sun Protection Factor (SPF) of 15 or Higher
A sunscreen is a product that you apply to the skin for protection against the sun's UV rays. Sunscreens are available as lotions, creams, ointments, gels and wax sticks. The American Cancer Society recommends products with an SPF of at least 15. The SPF number represents the level of protection against UVB rays provided by the sunscreen -- a higher number means more protection.

Be sure to apply the sunscreen properly. Always follow the label directions. Most recommend applying sunscreen generously to dry skin 20 to 30 minutes before going outside so the chemicals have time to absorb into your skin. When applying, pay close attention to your face, ears, hands and arms. Coat the skin that is not covered by clothing.

Be generous. About 1 ounce of sunscreen (a "palmful") should be used to cover the arms, legs, neck and face of the average adult. For best results, most sunscreens must be reapplied at least every 2 hours and even more often if you are swimming or sweating.

If you or your child burn easily, be extra careful to cover up, limit exposure and apply sunscreen. Do not use sunscreens on babies younger than 6 months. Instead, use hats, clothing and shading to protect small babies from the sun.

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 fabric draping down the sides and back, also is good. These are often sold in sports and outdoor supply stores. A baseball cap can protect the front and top of the head but not the back of the neck or the ears, where skin cancers commonly develop.

Wear Sunglasses That Block UV Rays
Research has shown that long hours in the sun without eye protection increases the chances of developing eye disease. UV-blocking 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.

Avoid Tanning Beds and Sunlamps
Many people believe that the UV rays of tanning beds are harmless. This is not true. Tanning lamps give out UVA and frequently UVB rays as well. Both UVA and UVB rays can cause serious long-term skin damage. Both contribute to skin cancer. Because of these dangers, the American Cancer Society advises people to avoid sunlamps and tanning beds.