Summer is drifting by isn’t it? The sun is still hot and heavy here. The temperatures are going higher as well. Different all over the world I’m sure. Last month I wrote about protecting your skin with sunscreens, hats and protective clothing.  This month I thought you might like to learn about how UV radiation affects us.

Ultraviolet (UV) radiation is a form of non-ionizing radiation that is emitted by the sun. It also comes from artificial sources, such as tanning beds mercury vapor lighting (often found in stadiums and school gyms), some halogen, fluorescent and incandescent lights and  some types of lasers. The beneficial effects of UV radiation include the production of vital nutrient, vitamin D, however, overexpose may present risks. Sunburn, premature aging, and skin cancer are all risks to overexposure. Keeping you and others protected from UV ratiation is an important, year-round responsibility. This goes for very young children as well. Just a few bad sunburns can lead to skin cancers later in life. The https://cdc.gov/cancer/skin/basic.info/children.htm site has further information on how to protect children from the ultraviolet radiation when outside.  Finding shaded play areas does help. But sunscreens must be used. For all ages.

Ozone depletion seems to be among the major concern as it contributes to skin cancer development. There has been concern that even on cloudy days we need to cover up and use sunscreen. But an article on the NASA’s Earth Observatory website brings some light on this issue. It reports that cloud cover plays a highly influenttial role in the amount of UV-A and UV-B radiation reaching the ground. Each water droplet in a cloud scatters incoming UV radiation back into space, so a thick cover of clouds protects organisms and materials from almost all UV. The larger the percentage of the sky that is covered by clouds, the less UV reaches the ground. the more opaque the cloud, the less UV-B. However, thin or broken cloud cover can be deceiving to people who are sunbathing, and the result can be an unexpected and severe sunburn. Remember too that if it is cloudy when you leave home, the sun can break through.

There are different types of UV radiation rays. UV radiation is classified into one of the three primary groups: ultraviolet A (UV-A), ultraviolet B (UV-B) and ultraviolet C (UV-C). This grouping is based on the measure of their wavelengths, which is measured in nanometers.

•  UV-A penetrates deep into the skin. It ages the skin, but contributes much less towards sunburn.
•  UV-B is responsible for the majority of sunburns.
•  UV-C could be the most dangerous of all, but it is completely blocked out by the ozone layer and doesn’t reach the earth’s surface.

Sunburn is a clear sign that the DNA in your skin cells has been damaged by too much UV radiation. Getting sunburn, just once every 2 years, can triple your risk of melanoma skin cancer.

Sunburn doesn’t have to be raw, peeling or blistering. If your skin has gone pink or red in the sun, it is burned by sun exposure. For people with darker skin, it may just feel irritated, tender and itchy.

Too much UV radiation from the sun or sun tanning beds can damage the genetic material in our DNA within skin cells. If enough DNA damage builds up over time, it can cause cells to start growing out of control, which can lead to skin cancer.

Your body has ways of repairing most of the damage. But it is not perfect, some damaged DNA can be left behind. Your body attempts to repair this damage is what causes the painful symptoms of sunburn.

Skin is composed of three layers. The outer epidermis mostly consists of cells called keratinocytes, which constantly grow outward, die and flake off, replaced by new cells. Next, is the dermis which houses sweat glands and hair follicles as well as nerves and capillaries. It is composed of collagen and elastin, the main structural scaffolding of the skin. At the base of the skin is the subcutis, an insulating fat layer.

The most common skin cancers are basal cell carcinoma, squamous cell carcininoma and the worst is melanoma. All can be serious. But melanoma can be life threatening.

is the most prevalent type of skin cancer. The most common site for this type of cancer is the face, especially the nose or ears, but it can appear anywhere. It is painless and slow growing and rarely spreads to other parts of the body.

Squamous cell carcinoma typically develops on the face (especially the lips and nose), the rim of the ear, and the back of the hands but can also appear elsewhere. If not treated, the lesions (notably large ones on the face and neck) can grow an spread, although this is rare. Squamous cell carcinoma is often preceded by precancerous lesions called actinic keratoses.

Each year, more than 5 million basal and squamous cell skin cancers are diagnosed in the U.S., about 80 percent fo these are basal cell carcinoma.  Both basal and squamous cell carcinomas have about a 95 percent non-recurrence rate when detected and treated early.

Melanoma is by far the least prevalent of the three common skin cancers, but it is the most dangerous. An estimated 87,000 new cases are diagnosed in the U.S. every year, with incidence having doubled since 1973, about 9,000 deaths annually are attributed to melanoma. White people are at 20 times greated risk than black people; overall, about 1 in 38 will develop melanoma.

Melanoma develop from melanocytes, cells located in the epidermis that produce melanin, the dark pigment that helps protect the skin from the sun’s ultraviolet radiation. Melanocytes are scattered throughout the epidermis and can also aggregate and form benign moles. Melanoma occurs when melanocytes begin reproducing. When melanocytes begin reporducing uncontrollably they form malignant tumors.

Melanoma and non-melanoma skin cancers can be invasive. As well as growing across the surface of the skin, tumors can sometimes grow down through the layers of skin. If the tumor grows through the wall of the blood or lymph vessel, cancer cells can break off and spread to other parts of the body. This is why skin cancer is usually easier to treat successfully when it is caught at an early stage. I am among the lucky ones. I had a melanoma 10 years ago. The biggest mole I ever had was on my upper chest. It began to change, the borders were irregular, and so was the color. I took it immediately to my dermatologist. It was successfully removed. It didn’t spread and was superficial. the best way to have them if you have to have them. I go yearly for checkups for all of my skin. I had many bad sunburns growing up. I don’t leave home without sunscreen all over my exposed skin and wear a hat!