SUNBURNS/TANNING

What is a sunburn?
What are some stats melanoma?
How do you prevent sunburns?
What does SPF indicate, and how much SPF is enough?

What is a sunburn?

A sunburn is a burn to the skin produced by overexposure to ultraviolet (UV) radiation. It is caused by exposure to sunlight and tanning beds, although occupationally from welding arcs.

How do you prevent sunburns?

Wear long-sleeved garments, wide-brimmed hats; use an umbrella when in the sun. Minimize sun exposure between the hours of 10 am and 3 pm.

What does SPF indicate, and how much SPF is enough?

In order to understand SPF (Sun Protection Factor), it is useful to know how the SPF is determined: usually test subjects have their skin exposed to tanning lamps, and the time it takes for the skin to turn red is determined. If the unprotected skin takes 10 minutes to turn red, while the adjacent skin with the sunscreen on it takes 120 minutes to turn red, then the sunscreen is determined to have an SPF of 12 (ie it takes 12 times as long to turn red). You will appreciate that this measurement might not be very useful.

Commercial preparations are available that block UV light; they are known as sunscreens. Sometimes called suncreams or sunblocks, they have a Sun Protection Factor (SPF) rating, based on the sunblock’s ability to reduce the UVB radiation at the skin: the higher the SPF rating, the greater the protection. A sunscreen rated SPF15 blocks 93.3% UVB and an SPF30 rated sunscreen blocks 96.7%. It is best to use a broad spectrum sunscreen in order to protect against both UVA and UVB radiation. It is prudent to use waterproof formulations if one plans to engage in water-based activities.

Sunscreen should have a SPF rating of at least 15. It should be applied half an hour before going out and reapplied every two hours thereafter.

Eyes should not be neglected, and wrap-around sunglasses which block UV light should also be worn. UV light has been implicated in pterygium and cataract development. Lips should also be protected with a lipbalm containing sunscreen (which needs to be reapplied frequently).

When one is exposed to any artificial source of occupational UV, special protective clothing (for example, welding masks) should be worn.