Summer is right around the corner, signaling the start of outdoor activities like barbequing, swimming, and hiking. However, exposure to the summer sun can also lead to sunburn, wrinkling, and even skin cancer. While outside, it is important to understand some basic facts about sun exposure so that precautions can be taken to protect your skin.
Research studies indicate that ultraviolet (UV) radiation is the single most important factor involved in the development of skin cancer. It is estimated that at least 90% of non-melanoma skin cancers and 65% of melanoma skin cancers are the direct result of UV radiation exposure. Having as few as five sunburns over the course of one’s lifetime is estimated to double one’s chances for the development of some form of skin cancer later on in life.
Not only does exposure to UV radiation lead to skin cancer, but also skin color changes and wrinkling, immune system weakening, and cataracts (an eye condition which impairs eyesight). A consecutive series of sun tans, whether deliberate or not, leads to skin that has a parched, damaged, and leather-like look.
UV radiation comes in two major forms: UVA and UVB. UVA rays are not absorbed by the ozone layer, penetrate easily and deeply into the basal skin layers, and are responsible for as much as 90% of the internal skin changes associated with aging. UVB rays are absorbed by the ozone layer, do not penetrate past the outer skin layer, and are the main cause of sunburns. With the recent thinning of the ozone layer, UVB radiation, as well as its associated sunburn, has become an increased threat to people.
UV radiation tends to be greater during the summer months. Furthermore, because it can penetrate past clouds, UV radiation can still be prevalent on cloudy or hazy days. Being near reflective surfaces such as sidewalks, water, sand, and snow increases one’s exposure to the sun’s harmful rays.
Guideline to follow
In order to protect yourself from the summer sun and its harmful UVA and UVB rays, keep to the following guidelines. If at all possible, avoid direct exposure to the midday sun (between the hours of 10:00 am- 4:00 pm), when chances of skin damage and sunburn are greatest. If you are outside during those hours, seek shade or wear protective clothing, such as a hat, sunglasses, and a long-sleeved shirt. Remember the shadow rule: if you do not see your own shadow, seek cover! If you would prefer less clothing or simply cannot avoid direct sun exposure, then make sure to use a sunscreen with a sun protection factor (SPF) of 15 or more. Sunscreens with SPF ratings of 15 or greater offer the best protection against both UVA and UVB rays.
Unfortunately, many individuals do not understand how sunscreens work and still end up getting sunburned. The SPF rating of any sunscreen is defined as the amount of time needed to produce a sunburn on protected skin to the amount of time needed to produce a sunburn on unprotected skin. So, if a person of fair skin type requires 10 minutes in full sun to sunburn, a sunscreen with an SPF rating of 3 extends that time to 30 minutes. If a sunscreen with an SPF rating of 15 is used, the time to sunburn is extended to 150 minutes.
Sunscreens are required by the Food and Drug Administration (FDA) to be tested for and marked by their SPF rating. Sunscreen SPF ratings can range from as low as 2 to as high as 60. However, just because one applies a high SPF sunscreen does not mean that the risk of sunburn is gone. Sunscreens can wear off as a result of sweating, swimming, or simple cloth-to-skin contact (such as while drying off with a beach towel). It is recommended that all sunscreens, regardless of SPF rating, be reapplied every two hours. It is also advised that the first application of sunscreen be allowed to absorb into the skin for at least 20 minutes before one goes out into the sun.
Not all sunscreens are created equal. Some provide UVB protection only (preventing sunburn), while others contain ingredients that protect against UVA rays as well. Because UVA radiation leads to deeper skin damage over time, it is highly recommended that you purchase and use these “broad-spectrum” sunscreens over the ones that block UVB radiation only.
Types of sunscreens
Broad-spectrum sunscreens use various ingredients to block or deflect UVA radiation. Either avobenzone or a benzophenone (such as dioxybenzone, oxybenzone, or sulisobenzone) is often used to absorb UVA radiation. Sometimes, these chemical compounds cause acne, dryness, or allergic responses for people with sensitive skin types. If so, there are other sunscreens which contain physical ingredients like zinc oxide or titanium dioxide. These physical ingredients are not expected to cause any skin reaction and they work by scattering and reflecting the sun’s rays. New developments with titanium dioxide and zinc oxide have allowed these physical blockers to become more transparent while still protecting against UVA radiation.
How to protect children
Young children are especially susceptible to blistering and sunburn. Even one incidence of sunburn in children under the age of six has been shown to significantly increase the risk of developing melanoma in adulthood. Likewise, children themselves are now developing melanoma, and at much earlier ages than before. Unfortunately, while sunscreens do protect against the risk of sunburn, they do not block all the sun’s damaging rays. Furthermore, there is currently no evidence to suggest that sunscreens protect one from melanoma or several other types of skin cancer. Because of this, when dealing with young children it is imperative to have them seek shade and wear protective clothing, especially during the peak hours of 10:00 am-4:00 pm.
Why are the peak hours of 10:00 am-4:00 pm so critical? Generally, the sun’s UV intensity is greater during that time, leading to a faster sunburn and resultant skin damage. The National Weather Service (NWS) and the Environmental Protection Agency (EPA) provide a daily forecast of UV intensity called the UV index. The UV index can vary from below 2 to over 11. The higher the UV index, the stronger the sun’s rays will be, and the greater the need for protective measures in order to prevent sunburn. One may find UV indices specific to zip code as well as time of day. People living in regions closer to the equator will experience a higher average UV index, regardless of the time of day. The UV index is particularly high for states such as Arizona and New Mexico, which helps to explain these states’ high incidence of melanoma and other skin cancers.
Is there such a thing as a healthy tan? The overall consensus is that no, there is no such thing as a healthy tan. Anytime the skin changes color due to sunlight exposure, irreversible damage has been done. What about the need to expose skin to sunlight so that the body naturally produces vitamin D? Currently, there are sufficient sources of vitamin D, such as in supplements and other foods (cod liver oil, fish, eggs), to make deliberate exposure to the sun unnecessary.
Skin cancer is a very real threat around the world. In the United States alone, skin cancer is the most common form of cancer. However, skin cancer is also the most preventable type of cancer. By taking such simple precautions as the wearing of protective clothing, putting on sunscreen, and avoiding the sun at peak hours, one can help lower the risk of developing skin cancer in later years. Furthermore, other results of sun damage, such as wrinkles and eye cataracts, can also be reduced or eliminated.