The good the bad and the ugly about sunlight and ultraviolet radiation

There is a growing hysteria in this country about the dramatic increase in the incidence of skin cancer.The number of malignant melanomas discovered in 1980 was 8000 by 1988 it had risen to 28,000.

That's a 250% increase in eight years.In 1930 one person in 1500 could expect to develop melanoma and experts project that by the year 2000 , one in 100 can expect to comtract it .Melanoma is the nost lethal form of skin cancer, it accounts for 75% of all skin cancer deaths every year.

The alarming part is that it accounts for only 5% of all skin cancers reported.In 1988 there were 500,000 casesof basal cell carcinoma reported in the U.S. and100,000 cases of squamous cell carcinoma.That means that the amount of all skin cancers is twenty times the incidence of melanoma alone.

Therefore it is reasonable to conclude that if the projection of one in 100 persons in America having melanoma by the year 2000 is correct then twenty times that is one in five persons having skin cancer of one form or another by the turn of the century. That's an epidemic.

The trends and statistics are alarming but evidence indicates that the conclusions being drawn are a little off base and the remedies being proposed could be exacerbating the situation.I beleive the reason for this is that the prevailing wisdom is proceeding from a false premise.

Logic dictates that if your premise is wrong you'd have to be one incredibly lucky person to arrive at a correct conclusion.That false premise is this: Ultra-violet light is bad for you.False. False. False.

Try this premise:

Ultra-violet is good for you. Aaahhh, that's better. Now let's look at the situation and see if we can make some sense of it.Radiation from the sun is a prerequisite for life on this planet.It consists of a band that is much broader than the visible band that we call light.

The low end of the band contains the infa-red that brings us the warmth of the sun. The high end contains the ultra-violet bands whose germicidal wavelengths purify the air we breathe and the water we drink. It also contains the ionizing wavelenths that excite the oxygen in the upper atmosphere into the ozone that protects us from harmful radiation.Ultraviolet light is separated into three categories; UVA,UVB and UVC.

In his book Sunlight Can Save Your Life Zane Kime demonstrated conclusively that sunlight has a metabolic effect on the human body that is very similar to that produced by physical training. He conducted an experiment where he compared the effects of several months of a gradual and consistent exercise program to the effects of a series of exposures to sunlight on human metabolism.

The findings were remarkably similar. In both groups there was a lowering of the resting heart rate, an increased ability of the blood to absorb and carry oxygen,increased energy and strength, lowered blood pressure,lowered blood sugar and an increased tolerance of stress.

Most animals are nocturnal.Man has a circadian rhythm that has him awake during the day. This rhythm is regulated by sunlight taken in through the eyes.The reduction of sunlight at the end of the day triggers the production of melatonin which is a "man" made sedative that encourages sleep.

The production of melatonin falls off in the morning when the sun comes up.Without getting into the complex physiology of it we need to understand that sunlight is one of the basic components necessary for a healthy metabolism. Let's use the previous statement to enhance our premise.Sunlight is one of the basic necessary components of a healthy metabolism. Aaahhh.

Of the other basic components food oxygen water and activity it is safe to say that too much too little or an imbalance of any of them can be harmful.

This holds true for sunlight as well.At the turn of the century physicians discoveded that sunlight was effective for treating tuberculosis. Psychiatrists are using the next best thing to sunlight ,full spectrum lighting, to treat people who suffer from chronic depression and Seasonally Affective Disorder it's SAD and it's working.

SAD sufferers are people who experience the sympyoms of depression during winter months. It is interesting to note that during trial studies researchers discovered that regular lighting was ineffective for releiving the symptoms, but full spectrum lighting was very effective at restoring psychological harmony to afflicted persons.

Most people who live in the northern latitudes experience the anxiety associated with sunlight deprivation during winter months. It's called cabin fever.A peculiar discovery was made back in 1971 at aresearch facility in San Antonio, Texas during a study that was being conducted on the alcohol preference of rats.

Researchers were surprised when they noticed that the rats were consuming much more alcohol on the weekends when the rats were left alone than during the week when they were experiencing the stress that was supposed to make them drink.
One of the researchers theorized that the reason for this could have been that the lab was dark all weekend and the lack of appropriate photoperiod was causing the animals to consume more alcohol. When they restructured the study to test this hypothesis they discovered that insufficient light induced a marked increase in alcohol consumption.

Rats maintained in a regular photoperiod that were injected with melatoni also exhibited an increased alcohol preference.

Enough about sunlight defficiency,let's get down to the nitty gritty.Back in the early seventies when it was discovered that the ozone layer was thinning the government meteorologists were concerned that more uv radiation would reach the earth as a result.

To monitor the situation they placed uv sensors at eight locations across the country at varying latitudes,longitudes and altitudes.They set the sensors to detect uv radiation of 297 nanometers in length. The is the wavelength that has proven most effective at bringing about erythema which is sunburn.

What they found out was very surprising.The amount of uv297 reaching the earth from 1974 to 1985 DROPPED on average 0.7% per year over that period. That's a 7% reduction in ten years.If the temperature dropped that much most of Canada would be a frozen tundra year round.During the same period that uv radiation dropped skin cancer more than doubled.Why?

One reason could be that sunscreens protect us from UVB which causes sunburn butthe majority of them dont block UVA which causes skin cancer.

This is an important thing to keep in mind while planning your sunlight diet because many people are exposing themselves to much more UVA than they would if they were not using the screens.Also accordibng to the FDA a majority of suntan lotions contain PABA which can be carcinogenic when used in sunlight.You mean that people are using chemical substances that filter out a portion of of the suns rays and are receiving an imbalanced light diet?

The average American spends twenty-two hours a day indoors beneath and around artificial light. Incandescent light has a narrow band compared to sunlight and is an inferior source of light nutrition.Fluorescent lighting has a very narrow band.
Think of sunlight as Wheaties.Think of incandescent lights as bleached white flour. Think of fluorescent lighting as cigarettes.Dr. Helen Shaw conducted a study at Sydney Hospital in Australia and found that office workers had twice the incidence of melanoma as people who work outdoors. Could the reason for this be that one group has a more balanced light diet than the other?

The body has an interesting way of metabolising sunlight .We mentioned melatonin and its effects on our sleeping cycles and how it is regulated by light sensors in the retina.The cornea plays a role in filtering ultra violet radiation and protecting the retina from cumulative uv damage.

As a person ages the cornea yellows to filter out uv radiation.Studies have shown that in children under ten 75% of uv radiation is transmitted by the cornea, by the time a person is twenty-five that amount is reduced to virtually zero.Ultraviolet light penetrates deeper into lighter skin than darker skin and can cause damage to subcutaneous tissue.

Your skin has melanocyte cells that release melanin when exposed to sunlight. Melanin is the skins protective darkening pigment whose presence we refer to as a tan.The human body is very familiar with sunlight and is well equipped to handle it.
Devices and solutions that alter or filter our light diet should be used sparingly.Take the advice of experts when dealing with the sun. Wear hats and protective clothing for sun protection.If you spend a lot of time indoors get a full spectrum light.
If you recognize sunlight as one of the basic life giving components you will exercise good judgement and be sure not to get too much or too little of it.Balance your light diet.