Page 72 - The Power of Light, Colour and Sound for Health and Wellness draft

WHEN LIGHT POLLUTES
Life on this planet evolved in the presence and under the infuence of the sun, and of diurnal patterns of light and darkness. Circadian rhythms of varying spans govern physical behaviour and responses for organisms from the simplest to the most complex. Much has been written about the effects of light on growth, health and functioning, but less on what a lack of darkness may mean for continued healthy existence. This article looks briefy at how light pollution, and specifcally Light at Night (LAN) is affecting our world.
For humans, biologically programmed to function in response to and at the light levels of sun, moon or stars, the addition of artifcial light is problematic. In the days of the incandescent bulb, the spectrum of which mimics that of sunlight, little harm was noted. But governments, in a mistaken move to reduce heat emission, have banned the incandescent bulb and promoted in its place a plethora of alternative light sources, most of which either omit parts of the spectrum that are essential light “nutrients”, or have heavy concentrations of energy in the blue range, or worse do both. Blue light hazard, from artifcial light, from monitor and device screens, not only poses a risk to the eyes potentially leading to macular degeneration, but also disrupts sleep and circadian rhythms, which in turn undermines health.
The hormone melatonin is produced in the pineal in response to circadian rhythms, with the highest levels occurring in the dark of night. This secretion is an anti-oxidant, a sleep-inducer, booster of the immune system, lowerer of cholesterol and regulates functioning of glands such as the thyroid, pancreas, adrenals, testes and ovaries. Exposure to light at night suppresses melatonin production, diminishing the effectiveness and reach of the hormone, thus it is not surprising that there are consequences for wellness.
In numerous studies, the late Professor Abraham Haim and his team at the Israeli Centre for Interdisciplinary Research in Chronobiology amply demonstrated causal links between LAN and breast and prostate cancer, the rates of which world-wide are escalating.
When external artifcial light is added to the night environment, though for town dwellers visibility outside may be improved, the added illumination is not necessarily benefcial to all sharing the space. Flora and fauna rely on the Earth’s daily passage from light to dark to thrive. For plants, adequate photosynthesis, the regulation of growth and fowering, the taking up of carbon and the release of oxygen occur in this rhythm. Alter the
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