Sun and fun

We all love a sunny day, especially when traveling. The sun lifts our spirits, gives us vitamin D, warms us, lights our way and gives life. But the sun is a double-edged sword; it can cause sunburn, dehydration, heat stroke, drug reactions, premature aging of the skin and skin cancer.

The sun can do all this through electromagnetic radiation, primarily ultraviolet radiation, or UV. Most of the sun’s radiation is blocked by the ozone layer present in the Earth’s atmosphere, but as the ozone becomes more and more depleted, more of this radiation is making it to the surface of our planet.

There are two types of UV radiation we are most concerned about: UVA and UVB. UVB does most of the damage, but UVA can also damage skin and is primarily responsible for photosensitivity and certain drug eruptions (reactions and rashes) that occur while taking certain medications (such as tetracycline, doxycycline, Retin-A, lasix, PABA, some antiinflammatories and a host of others).

UV radiation can travel through clouds: cloudy days are no protection from sunburn. UV radiation can also reflect off the surface of water and snow.

In the tropics and very sunny climes, avoid the sun between 10 a.m. and 2 p.m., wear protective clothing/hats and sunglasses, drink lots of fluids, avoid alcohol, use air-conditioning when possible, and always use sunscreens and lip balms with UVA and UVB sun protective factor of a least 15; SPF 30 or 50 is better. While both roughly block UV equally in real terms, SPF 50 lasts longer.

SPF, Sun Protection Factor, tells you the relative amount of time you can spend in the sun. An SPF of 10 offers 10 times the protection of not using any sunscreen. If it takes you 10 minutes to burn normally, then wearing an SPF of 10 lets you stay out for roughly 100 minutes before you would burn, but there is variation based upon the amount of sunscreen and one’s underlying amount of melanin.

Ideally, get a sunscreen that is waterproof or be, at the very least, conscientious about reapplying regular sunscreen after exiting water. Not all sunscreens protect against all solar radiation, and labels should be read carefully. Zinc oxide can be worn for completely blocking solar radiation.

Most people let their guard down and don’t reapply suncreen as often as necessary, nor is enough placed on the skin to give a good amount of protection. A thin coat, or one washed off by swimming, won’t protect you properly from solar radiation.

When you put on insect repellent, it is best to put on sunscreen first, then the repellent. If you can wait 15 to 30 minutes between the two, it will let the sunscreen soak into the skin and the insect repellent will then sit on the skin, which is more effective.

If you do get a sunburn, put on cooling salves, but make sure they are not petroleum-based. Aloe vera is good, as is vitamin E. Wear loose-fitting clothing, and take analgesics like aspirin or ibuprofen. The new skin that appears after a burn is sensitive, so try not to burn it again!

And know that the younger you are when exposed to tanning or sunburns, the higher that your risk of skin disease, especially cancer, is later in life. So protect yourself!

Healthy travels!

—Travel & Health is written by Alan M. Spira, M.D., DTM&H, FRSTM