I should begin by defining scotobiology.

Scotobiology is the study of the biological need for periods of darkness.

It will be a surprise to most people that light is not always good! The studies and data supporting this point of view had been with us since the days of natural philosophy in the 19th century. But then, as now, daylight was believed to be always good, and night was a period through which life had to endure. Recent reviews of this data have found a general trend that life needs a period of darkness.

We don't seem to need complete darkness. Most life has evolved to accommodate starlight. It also accommodates bright moonlight for about a week every month. But it needs the remaining three weeks of only starlight to recover from the bright Moon. Any more light changes the behaviour of animals because it is not an environment for which they have evolved.

Behaviour can change within a generation or so, but our biochemistry cannot. Our biochemistry must "evolve", which takes 10,000s years.

The term scotobiology was coined by Dr. R. Bidwell a botanist at Queens University in Kingston, Ontario (now retired). The term has become more widely known with the support and promotion of Dr. D. Welch of Parks Canada (now retired) and Peter Goering of the Muskoka Heritage Foundation (now retired). (This seems to be a subject for old people!)

    Biology of Darkness

My interest in scotobiology began at the Ecology of the Night Conference in the Muskoka District north of Toronto in 2003. I began as a sceptic. Although I knew outdoor lighting could be a nuisance, I did not believe that something as ubiquitous as outdoor lighting could have a profound impact on health. This new knowledge has motivated me to redirect the Light Pollution Abatement Program of the Royal Astronomical Society of Canada (RASC) to include environmental protection, wildlife, and human health as the chief motivators for the reduction of light pollution.

Support for scotobiology is based on an extensive literature review undertaken by many people. One survey has been published by Rich and Longcore in 2006, The Ecological Consequences of Artificial Outdoor Lighting and published by Island Press (ISBN 1559631295).

I believe the connection between artificial light at night (ALAN) and human health is due to the effect of ALAN on our body's perception of the time of day (or night). If readers doubt the importance of scheduling biochemical processes in our bodies, they may review an overview on the subject by W. L. Koukkari and R. B. Sothern (Introducing Biological Rhythms, Springer Science, 2006, ISBN 978-1-4020-3691-0).

ALAN has become known as a "sleeper" pollutant that has profound impact on our physical and mental health, and fundamentally changes the natural environment.

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