Chemistry hits the beach
Chemistry hits the beachIn our society it's a given that suntans look attractive, and it's also understoud that they can be harmful, and downright unhealthy. So what does this mean? This means that there is a multi-million dollar a year industry that researches and manufactures UV absorbing and blocking lotions that are designed to prevent skin damage from tanning and burning. It is a prime example of the use of chemistry to improve the quality of life for many people, writes Wyn Locke.1
Our obsession with getting tanned, has boomed since the 1970s, and the outbreak of packaged tours. The "tan now" and "hurt later" philosophy has led to the sun-worshipping of everyone from the golden gods to the fair-skinned "burn 'n peelers", which results in a copious amount of lotions and creams being slathered on everyday. These lotions are, usually, sunscreens or sunblocks, meant to protect us from the blisters, the pain, and in general to keep our youthful glow lasting just a few years longer.
A sunguard is a cream designed to protect one's skin from being sunburned. Our bodies are incrementally damaged by each new exposure to the sun, and this damage can later be seen in the form of wrinkles, blotchy skin and even skin cancer. Sunscreens have evolved a goodly amount over the years. Christopher Columbus noticed in 1492 that the natives of Hispaniola would protect themselves with red paint, as to avoid sun damage. The ancient Greeks, who trained for the Olympics in the nude would rub themselves with a mixture of sand and oil, which provided an opaque protection from the sun, and were sweat resistant. These notions resemble those of earlier modern day technologies. The minerals most often used in conjunction are either oxide of zinc of titanium. These are the sunscreens that graced the noses of every red suited lifeguard in the 50s.
Today's modern world, demands an absorbing lotion, one that protects the skin, but avoids the look of being painted like a clown. A notion so simple as a transparent, UV ray blocking or absorbing protection, isn't quite as simple as first suspected. Firstly we must understand which compound will do this best, and to understand that, we must know what it is protecting us from. There are three types of UV rays, UVA, UVB, and UVC. UVA rays have the lowest energy, they are found having wavelengths of between 320 and 400 nanometers, and account for 90% of the UV rays which reach the earth. They cause little burning, but penetrated deeply into the epidermis, and are therefore the cause of early aging due to sun exposure. UVB rays are slightly higher in energy, and account for the remaining rays which reach the earth. They have wavelengths of between 290 and 320 nanometers and are the primary burning and tanning rays. These are the highest contributors to skin cancer. Lastly are UVC rays, which do not often reach the earth, due to the Ozone layer....
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