Before Going On Vacation

It’s the summer time and you may be planning to spend a lot of time outdoors on your summer vacation.  Remember that it’s important to develop a base tan and schedule enough time to develop it gradually.

Moderate exposure to ultraviolet light helps develop a natural barrier in the skin to protect the body from future exposures to UV light; it increases your tolerance to UV.  Ultraviolet light stimulates the production of melanin which then surrounds the core of cells to protect the DNA.  This melanin substance absorbs and / or scatters radiation.  In addition, exposure to ultraviolet light thickens the epidermis (the top skin layer), thereby limiting the amount of UV which could penetrate the lower skin layers.  If this photo-protection (base tan) is not developed or a sunscreen is not used, sunburn can occur and the DNA of the skin cells may become damaged.  Repeated sunburn can result in damaged cells. Therefore, it’s wise to use a broadband sunscreen while exposed over a prolonged period of time or in sun-intensive regions.

Skin damage may occur if a person overexposes the skin to UV or combines exposure indoors with too much exposure to the natural sun.  One should always be mindful of the dangers of overexposure, as it may lead to chronic skin damage.

Your tan will disappear or fade over time without repeated exposure to UV light. This is because the pigmentation process occurs in the epidermis, the top skin layer.  The epidermis replaces all its skin cells every 28 – 30 days.  Cells in the inner portion of the top skin layer divide themselves, migrate to the surface, gradually die and slough off.  Skin cells contain melanin which is darkened as a result of UV exposure.  If a person stops tanning for an extended period of time, they will probably have to start at the beginning using the recommended exposure schedule for their skin type. Subsequent session times may be gradually increased, leaving at least 48 hours between each exposure.  This schedule assumes, however, that no unusual reaction or sunburn occurs. 

If you decide to use a spray booth or self bronzer for that “immediate” tanned look, remember that these sources do not provide a natural barrier, or photo-protection, and will leave you susceptible to obtaining a sunburn when going outside or are otherwise exposed to UV light.  Moderation is the key and always use an SPF when outside for extended periods of time. 

Here are a few basic tanning tips before heading outside:

  • UVB irradiance is greatest between 10:00am and 2:00pm.  UVA continues throughout the day and can exceed that of UVB by 10 to 1,000 fold.  In the northern hemisphere, UVB is most intense in summer months, but UVA is more consistent throughout the year.
  • SPF stands for “Sun Protection Factor” (maybe it should stand for Sunburn Protection Factor) and is the standard means of expressing a sunscreen’s effectiveness in protecting the skin.  It represents a ratio of the minimal erythemal dose (MED) to the Med on unprotected skin.  The SPF value is the length of time a person can be exposed to UV without burning when a sunscreen is applied compared to when it is not.  For example, an SPF of 15 means one can be exposed 15 times longer with a sunscreen than without it.  Your skin alone has SPF 1.
  • Sunscreen chemical agents are divided up into three groups: those which absorb UVA, those which primarily absorb UVB and those which absorb both wavelengths.  It is preferable to select broadband or full-spectrum sunscreens, as they protect against both UVB and UVA penetration.  They also will help prevent the cumulative damage of photoaging (wrinkling) and can minimize photosensitivity reactions, both of which can be caused by UVA.
  • Sunblocks are opaque formulations which absorb, reflect and scatter up to 99% of both UV and visible light.  They are often used on localized, sun-sensitive areas such as the nose, lips, ears and shoulders.  Because they are often messy and may stain clothing, sunblocks may not be practical for application over large areas.  An example of a sunblock is zinc oxide.
  • On the other hand, sunscreens absorb specific wavelengths and are classified as drugs by the FDA.  Sunscreens are considered more cosmetically refined due to their pleasing consistency and are, therefore, typically used for effective photoprotection.
  • So remember, when outdoors, the sun is the strongest between 10:00am and 2:00pm.  It is wise to use a broadband sunscreen while exposed over a prolonged period of time or in sun intensive regions.  One should always be mindful of the dangers of overexposure, as it may lead to skin damage.   And don’t forget to visit your local tanning salon to work on your base tan before hitting the beach.