2. Natural Light Versus Artificial Light
Sunlight, when broken up by means of a prism, is found to be con posed of the color bands of the spectrum—red, orange, yellow, green, blue, indigo and violet. These different colors represent different rates of vibration, increasing as we go from red to violet, while their wavelengths decrease. These visible rays give us sensations of light, color and heat. In addition to these color rays, sunlight also contains other rays not perceptible to our ocular sense and therefore invisible. The wavelengths immediately shorter than visible violet and those immediately longer than visible red are both invisible to humans and are called ultraviolet and infrared, respectively.
Regarding the heating power of sunlight, it is found to be greatest at the red end of the spectrum where it blends with the infrared rays, while the greatest chemical activity takes place at the violet end, blending with the ultraviolet rays. These invisible rays of the sun are the most beneficial ones. However, the complete color spectrum, blended in perfect proportion so as to produce white light, is needed for ideal growth and development of both plants and animals.
Artificial light does not radiate a complete spectrum but instead produces a light with an excess of one or more of the color rays. In the case of incandescent lighting, most of its light is yellow, orange and red, whereas the standard “cool white” fluorescent light emits mostly yellow-green light. The various so-called “sunlamps” produce either too much ultraviolet or too much infrared radiation and are definitely harmful. They may cause headaches, third-degree burns and severe conjunctivitis.
The effects of artificial lighting have been noticed in both plants and animals. John Ott, of the Time Lapse Research Laboratory, discovered that the apples on a branch of a tree under artificial light grew larger than those growing under natural light, but they did not mature or ripen. Despite the addition of many chemical products to produce more color in the fruit, the fruit never acquired color until exposed to ultraviolet rays from the sun.
Further observations made by Ott revealed that the ratio of the sexes of plants was affected by different wavelengths of the spectrum. Experimenting on a pumpkin vine raised in a basement under a skylight and a cool, pinkish, white fluorescent light, it was noticed that the female pumpkin-producing flower turned yellow, then black and finally dried up and dropped off the vine. Consequently, the vine did not produce fruit. When these lights were replaced with tubes containing more blue in them, the female buds developed bountifully, while the male buds dried up, turned black and dropped off the vine at an early stage. The usual ratio of male to female buds on a pumpkin vine is seven to one respectively; however, in these artificially-lighted plants, normal reproduction could not take place.
In general, it has been observed that plants grown in artificial light lack the rugged constitution
of plants grown under natural lighting conditions. Their growth may be stimulated by subjecting them to longer hours of light, as compared to the natural light cycle of the revolving earth. But this forced growth produces plants bearing flowers and fruit of lesser quality and color appeal than those grown in sunlight.
The animal world is also adversely affected by variance of light wavelengths. In an experiement conducted to determine the effects of different light on animals, 1000 mice were used and divided among three different light environments: Those receiving natural daylight produced an equal amount of male and female offspring; those under white fluorescent bulbs produced 70% females and 30% males; and those under pink fluorescent bulbs produced 30% females and 70% males. This latter group did not thrive as well as either of the two other groups. All those exposed to the pink light quit breeding two months earlier and died one month earlier than those exposed to the white light.
As these experiments were made with a strain of mice in which malignancy develops in 98% of them, almost all the mice did succumb to cancer. However, those mice under natural daylight developed cancer two months later than those under the white fluorescent bulbs, and three months later than those under the pink fluorescent bulbs. An additional effect was noticed: Those mice receiving the pink light gave birth to young which were smaller in number and size than those mice receiving natural light.
Other investigations have shown that light definitely affects the pituitary gland, as well as other areas in the midbrain and hypothalamic regions. In the early 1920’s, William Rowan demonstrated that the varying seasonal lengths of the daylight was responsible for the migration of birds. In other studies conducted by Bochenek, Marburg and Gudden, it was shown that light may occasion reaction on the entire endocrine system of an animal via nerve impulses originating in the retina and reaching other areas of the brain by way of accessory optic pathways. Thus, artificial light, not being of the same quality as natural light, can play havoc with the endocrine system via the nerves.
A study was conducted involving some elderly men at a nursing home who spent most of their time indoors under the influence of unnatural lighting. They found that these men suffered a severely diminished ability to absorb calcium; yet when the lights were replaced with special bulbs designed to
simulate sunlight, their calcium absorption was increased by 15% within a month. Even more disturbing research conducted by scientists has indicated that fluorescent lighting can cause genetic mutations, cancer and death in the cells of many life forms, including humans.
Aside from the facts concerning the direct negative effects of unnatural lighting; we must also consider their more indirect effect on our body rhythms. Their presence, by turning night into day, tend to imbalance the circadian rhythms—the regular cycles of rising and falling body temperature, variations in body chemicals, etc., that naturally occur approximately once every 24 hours. The result may be what three West German photobiologists have called “light stress.”
All plants and animals require alternating periods of light and dark so that some vital processes may rest while others become activated. The anabolic activities during the night can take place efficiently only when not interfered with by lighting, which will continue to occasion activity in the living cells. The result is that the processes of growth and repair are interrupted, resulting in the necessity for disease, and the body is robbed of a certain degree of life force.
Experiments testing the influence of artificial light on fish revealed that, when exposed to too many hours of light, the fish ceased to reproduce. When time exposed to light was cut down gradually over a period of weeks, the fish resumed reproduction if exposed to pink light, but not under the slightly bluish white light. Also, under the pink light, the ratio of female to male offspring was 80 to 20 respectively and the development of the secondary sex characteristics of the male offspring was retarded.
Regarding humans, some scientists suspect that the age at which girls reach sexual maturity might be influenced by the artificial illumination of nighttime. It has been noticed that in countries experiencing long winter nights, girls are now reaching sexual maturity months or years younger than their grandmothers did. Apparently, their normal maturation cycle is being interfered with by the introduction of artificial lighting into their lives, thereby increasing the rate at which they mature.
From this information, we may understand the importance lighting plays in our daily lives and we may also suspect that all the effects of artificial lighting have yet to be uncovered. A true science of health must endeavor to ascertain all aspects of life and living and their ultimate effects on human health.