Ultraviolet rays - the invisible enemy

Sunlight contains both ordinary, harmless, visible light and shorter, invisible light rays called ultraviolet light. Tanning, burning, and skin damage from sunlight are caused by ultraviolet rays. Since ultraviolet rays produce both tanning and skin damage, it's impossible to tan "safely" and avoid permanent skin damage. Discussions on sunbathing that describe "safe" tanning refer to avoidance of sunburn. By proper timing, most persons can get a deep tan without sunburn. However, no one can get a tan without some skin damage.

Blocking out all light with clothing is most effective. Certain sun protectives depend on the same principle. They coat the skin with a paint-like pigment that mechanically blocks light. They work well, but they're messy and rather unsightly.

There are also many clear sunscreens that absorb ultraviolet light. These "clean" sunscreens contain either PABA (para-aminobenzoic acid) or a benzophenone compound. Some of the PABA-containing sunscreens are taken up by the skin and will provide some protection in the water provided they're applied one or two hours before swimming. An occasional person is allergic to PABA or its derivatives, so please try PABA-type sunscreens on a small area of skin before spreading it all over your body. The other chemical class of sun protectives, the benzophenones, rarely cause skin allergy. Benzophenones wash off, however, and therefore do not protect swimmers. Some benzophenones have a bitter taste that can be annoying when applied near the mouth.

There are many sun protectives on the market. The better ones are labeled with a number called the sun-protective factor (SPF). The higher the SPF number, the better the protection. The best sunscreens have an SPF of 15, and are what you should use.

Water removes most sunscreens. Remember to put on another coat of sunscreen after swimming or bathing. If you're sweating heavily, use some more sunscreen every hour or two. If you're in very bright sunlight, it's wise to protect your skin as much as possible with clothing (long sleeves, gloves, wide-brimmed hats) and use one of the "clean" chemical sunscreens on the parts of your skin exposed to the sun.

Protect your lips from sun damage. The darker lipstick shades are effective for women. Men, and women who don't wear lipstick, should use an ultraviolet-absorbing lip pomade. Women can use makeup with a sun protective. The sun protective should be applied first, then the makeup. The makeup itself, especially if heavily colored, provides some sun protection. .

93 million miles away, there is a luminous celestial body called the sun. The sun, which is a source of energy, without which this earth cannot function, is a blessing to most, but a curse to others. You should aim to minimize sun exposure, not avoid it.

Each year with the arrival of the summer solstice, June 21st to be exact, our mixed blessing is increased with the onset of the most intense period of sunlight to which we are all exposed.

Humans have worshiped the sun since primitive times. Little wonder was raised to the status of the gods, for its light and warmth would bring comfort, dispelling fear as it chased away the cold dark night. .

But in modern times, sun worship has taken on a different form, that of an uncontrolled exposure to sunlight in order to achieve a "tan".

As recently as the Victorian era, however, the opposite was a rule. Alabaster white skin was prized and protected by long garments, broad hats, and parasols. This was true even in the early cultures that paralleled the religious worship of the sun. The aristrocats of Crete preserved white skin by remaining indoors in contrast to the nut brown skin of field workers.

But the colonial British in Africa and India did not have the good sense to avoid the sunlight-prompting the fame tune by Noel Coward, "mad dogs and Englishmen go out in the noon day sun".

It was only recently that medical science began to recognize the harmful effects of sunlight. It was in 1870 that dermatologists first began to speculate about the connection between sun and skin tumors. By the turn of the century, the famed German Jewish dermatologist, Gersham Unna, demonstrated the length between the generation of the elastic tissue of the skin called solar elastosis, and the development of abnormal thickenings of the skin that we call solar or actinic keratoses, and skin cancers in sailors and farmers.

Sunscreens

The food and drug administration presently classifies sunscreens as "drugs" intended to protect the skin against actinic or solar damage.

Solar protective preparations that can be applied to the skin are chemicals in the form of solutions, gels, creams, or ointments that we hope will attenuate the bad effect of sunlight due to both UVA and UVB. Protection is afforded by the sunscreen through active ingredients that absorb, reflect, or scatter the solar radiation that strikes the skin.

Topical sunscreens can either be chemical sunscreens or physical sunscreens. Chemical sunscreens contain one or more ultraviolet absorbing agents that, when applied in a thin and usually invisible film, act as a filter to diminish the penetration of the ultraviolet to the living portion of the epidermis. The most widely used of the sunscreens in this category contain paraaminobenzoic acid or poppa or a derivative of poppa, centamades, benzyphanone, salicylate, and antyelates.

Physical sunscreens on the other hand are usually opaque formulations that contain materials that are particulate in nature. These do not selectively absorb the ultraviolet, but rather, when applied in a thin film, primarily reflect and scatter the ultraviolet because of the particles they contain.

These agents are titanium dioxide, talc, zinc oxide, kaolin, ichthamnol, or pharachloride. These are usually very messy and not very cosmetically elegant. In contrast to the chemical sunscreens, they are not easily washed off and have the important property of sticking to the skin that is referred to as substantiveness.

Several years ago, professor Phrons Griter of Austria proposed a concept that is now well known in this country. He proposed a means of grading sun protective materials that is referred to as sun protection factors.

The SPF is defined as the ratio of the least amount of ultraviolet B energy required to produce a minimal redness reaction in skin through a sunscreen product film to the amount of energy required to produce the same redness on skin without any sunscreen application. As a standard for comparison, a solution of 8% homomenthol salicylate is given the SPF of 3.5 to 4.5.

As a biological system being measured in one individual for use in another individual, it is apparent that the values are only at ball park approximation. Indeed there are so many factors that influence the actual performance of a sunscreen with the same SPF that it is remarkable there is any uniformity at all.