How Light Pollution Works

How Light Pollution Works: Author's Note
Jessika Toothman, Staff Writer
Jessika Toothman, Staff Writer
HowStuffWorks 2009

Living in a large, sprawling city, I was no stranger to light pollution before I wrote this article. But I was very interested (and a little alarmed) to learn about all the ways light pollution negatively impacts both the animals and people exposed to it. Several life cycles, among them sleeping, breeding, migration and feeding cycles, can be affected by an overabundance of improperly timed light. And to a large extent, humans aren't spared from this. Light during hours of darkness decreases the production of melatonin, which can disrupt a whole host of bodily functions.

I think the most provocative thing that I read, however, was this: By frequently and fundamentally altering our collective circadian rhythms, we are in fact running a massive global experiment. Humans -- and the plants and animals that exist around us -- evolved to follow set natural patterns, such as appropriate times for sleeping and waking, from the tiniest beetles and bats right up to the biggest CEOs and most-relied-upon RNs. We now routinely defy that millions-of-years-in-the-making dictate. I hesitate to imagine the results of this experiment if it fails.


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