Protect yourself year-round with knowledge, clothing, sunscreen & vitamin D
As May is Skin Cancer Awareness Month, we at cCARE want to take this opportunity to provide you with some information that will help you to protect yourself from skin cancer while enjoying the California sun.
Why can sun exposure be dangerous and lead to skin cancer? Ultraviolet radiation. There are typically three energy levels, referred to as UVA (ultraviolet A or long wave), UVB (ultraviolet B or medium wave) and UV-C (ultraviolet C or short wave). In most cases, UV-C does not reach the earth’s surface in appreciable quantities. However, both UVA and UVB reach the surface of the earth and have the potential to cause us problems. This energy can penetrate into the superficial layers of the skin and interact with DNA in the cells.
This interaction can result in damage, which in most cases is readily repaired. But occasionally, the damage is not repaired correctly and the cell begins to lose control over its growth. When cells lose complete control, we have the development of a cancer. In this case, some form of skin cancer.
There are three major forms of skin cancer: basal cell, squamous cell and malignant melanoma. The basal cell and squamous cell carcinomas are by far the most frequent skin cancers. In general, it is estimated that more than 1 million people will develop a basal cell carcinoma this year and another 700,000 will develop a squamous cell carcinoma. These diseases are typically not life threatening.
Malignant melanoma is a very different form of skin cancer that if not discovered early is uniformly fatal. Once again, there is very strong evidence that melanoma is caused by exposure to the ultraviolet radiation from the sun. Therefore, this is a disease that is preventable if we protect our cells appropriately. Like other skin cancers, in some cases there are precursor lesions that can be recognized by your dermatologist and can be removed if necessary.
Peak UV exposure times (and places)
UV exposure during the hours of 10 a.m. to 3 p.m. is particularly problematic. This is a period during the day when the sun is highest in sky. Ultraviolet radiation from the sun has the shortest distance to travel during these particular hours and we are exposed to more UV radiation then.
In addition to the time of day, it is important to recognize that how high above sea level we are is also problematic. For every 1,000 feet of elevation we increase our UV exposure by about 5 percent. So in Southern California if you are up in the mountains at Big Bear, you’re going to receive 40-50 percent more UV radiation than you would have at the beach for the same time of exposure.
It’s important to remember that UV radiation penetrates cloud cover. Approximately 85 percent of UVA and UVB will pass right through the clouds, potentially causing significant UV damage to your skin. We have a tendency to have a false sense of security because when we are outside on a cloudy day we feel cool and have a tendency not to worry about sun exposure. But a portion of the radiation from the sun is generated as infrared rays, which are blocked by clouds where UV radiation is not. So be careful even on the cloudy day.
Another important aspect of assessing our UV exposure is being aware of the UV index, which is a measurement of the amount of UV exposure that will be reaching the earth’s surface at a particular location on a particular day. There is an excellent web page published by the Environmental Protection Agency (EPA) that will allow you to enter your ZIP code and get your UV index reading for the day.
April through October typically consists of a very high or extremely high UV index every day. These are the top levels of UV exposure and represent numbers that should cause significant concern. For individuals who do not tan well, spending as little as 10 minutes of unprotected time in the sun during these months can cause significant UV damage.
How to protect yourself from skin cancer
The best thing we can do is avoid the sun completely. However, that’s not something that we can reasonably expect to happen living in California, so the next best thing is to protect ourselves. In situations where we cannot avoid the sun, we need to take steps to protect ourselves.
The more clothing we wear the better the protection will be. In some cases, clothing is being manufactured with what’s referred to as the ultraviolet protection factor (UPF). However, this is not widely available in normal clothing yet, so you’ll need to assess the protection of your own clothing.
An easy way to gauge the protective ability of your clothing is to put your hand in a single layer of the clothing. Then put your hand up to the backlight of the sun or a strong light. If you can see your hand, it is likely that UV radiation is getting through to your skin. Some useful guidelines:
• A typical men’s white T-shirt has a UPF of 7
• If it becomes wet the rating falls to 2
• Denim jeans typically have a UPF of greater than 1,500
• Obviously, the thicker the material, the tighter the weave and the better the protection.
A wide brim hat can provide substantial protection in the head and neck area. Typically, the brim needs to be four inches as a minimum and completely surround the hat. Baseball hats do a reasonable job of protecting our foreheads, but little else.
Sunscreens for the average person should be rated SPF 30 (sun protection factor of 30) and above. Remember, the sunscreens must be applied 30 minutes before you go out in the sun and re-applied every two hours. In general, for an adult wearing a bathing suit, a full ounce of sunscreen needs to be applied. This is typically measured as a shot glass full.
Many of us wear sunglasses when we’re outside, but make sure that your sunglasses are UV coated. Melanoma can develop in the eye and many experts believe that the modest increase in the frequency of this form of melanomas may be related to sunglasses that do not have this protection.
There is growing evidence that vitamin D has important anticancer properties. Malignant melanoma may be especially influenced positively by this vitamin. Individuals with adequate levels of vitamin D seem to have less risk of developing this cancer than those who have lower levels. The next time you visit your primary care physician, request that your vitamin D levels be measured to make sure your levels are in a healthy range.
Remember, you can enjoy the sun with the proper protection noted above and reduce your risk of all types of skin cancer.