Excessive light at night contributes to pollution?!
According to the National Oceanic and Atmospheric Administration (NOAA) excess light at night can contribute to air pollution. This data (which I learned about through my association with the International Dark-Sky Association) was recently presented at the American Geophysical Union in San Francisco.
As the IDA described the findings:
Every night, chemicals from vehicle exhaust and other human created sources are broken down and prevented from becoming smog, ozone, or other irritants by a form of nitrogen oxide called the nitrate radical. Sunlight destroys the naturally occurring nitrate radical, so this process occurs only in hours of darkness.
Measurements taken over Los Angeles by aircraft show that light pollution from cities is suppressing the radical. Though the lights are 10,000 dimmer than the Sun, the study’s first results indicate that city lights can slow down the nighttime cleansing by up to 7% and they can increase the starting chemicals for ozone pollution the next day by up to 5%.
That light actually prevents some pollutants in the air from being dissolved is perhaps the most intriguing, but only the newest of innumerable reasons we need to do something about light pollution. I’ve been interested in light pollution for quite some time and have been a member of the IDA for a number of years. My initial interest stemmed from my sadness over the fact that stars are becoming increasingly difficult to see at night. And not just in cities, but in suburbs, exurbs, and even rural areas. The skies we all see at night are very different and much diminished in stariness than all of history up till the past 100 and really past 50-odd years.
But light pollution also has gained my interest as another example of a condition that we all live under, that deeply affects our lives, yet we hardly think about or even notice at all. (I need to think of a term for this phenomenon of living in an unseen reality. It is at the core of FDS, and seeking to be aware of these unseen realities, I believe, is the cornerstone of an enlightened existence. I often think of this phenomenon as connected with Plato’s Allegory of the Cave, yet instead of one “reality” outside the cave, there are innumerable realities.)
Though concern over light pollution has been growing in the past some-odd years, it is still a tiny movement. Yet light pollution, I’d argue, is one of the biggest environmental problems facing us. Foremost, perhaps, when we think of light pollution, if it’s thought of at all, we think of the extraordinary electricity usage it requires. But secondarily, and what largely goes unnoticed for most of us, is the psychological effect of never experiencing darkness. On the IDA’s website (and elsewhere) you’ll find reams of data showing a multitude of negative effects on the human body and mind from excessive light at night - increased cancer risk and depression among the most evident consequences.
Of course the benefits of electric light at night are inarguable. But the costs of excessive light are rarely discussed, and are often misunderstood. Just as we need a break from endless noise, we need a break - physically, mentally - from endless light. We operate on circadian rhythms, and our refusal of darkness - for the intention of safety, for entertainment, for work - is another example of our biology not being able to keep pace with our technology.
