They say, “a little knowledge is a dangerous thing.” Then again, they also say, “ignorance is bliss.” So, take your pick. In any case, have you noticed that lately some streetlights are emitting blue or purple light? I mean, what’s up with that? If you search the Internet you’ll find all sorts of conspiracy theories ranging from government surveillance technology to psychological control to insect eradication. But before anyone starts to hyperventilate, the Iowa Department of Transportation has just released an official statement that the reason some street lights are turning blue is that the phosphorus coating on LEDs (which makes the light white) has been flaking off, revealing the natural blue color. The IDOT assures us that all the weird blue lights are getting replaced. So, we can relax.
But, of course, the conspiracy theories are more fun. One theory is that blue lights have a calming effect on people, even reducing depression with those suffering from seasonal affective disorder. It’s supposed to make us think of the ocean or the sky. There have even been (admittedly dubious) studies in Scotland and Japan, suggesting blue street lights in certain neighborhoods reduced crime rates and the number of suicides. But Tsuneo Suzuki, color psychology professor of Keio University scoffed at the notion, saying there is no credible research to support the idea and that if anybody could show that blue lights reduced suicide, they “would probably win the Nobel Prize.”
One of the nuttier theories claims the blue lights are really “black lights”, the kind that make certain paints glow like in Halloween spook houses. They say the lights are designed to identify drug users—as if stoners are not paranoid enough. “Dude, look! I’m glowing blue! Quick, throw the weed out the window!”
As a side note, it is interesting how some things do glow under black light—like tonic water and tooth whiteners. When I lived in Arizona, some people hunted scorpions at night with a black light, giving them a ghostly glow. Vaseline glows under black light. So does ketchup and honey and vitamin A and B. Crush a vitamin B-12 tablet, dissolve it in vinegar and watch it glow bright yellow under black light! Cool!
There was a study in England that concluded LED street lights reduced insect populations along roadsides. The “researchers” determined the lights inhibited insect feeding habits after whacking the bushes with sticks and counting the number of caterpillars they found. Maybe getting whacked with sticks could also have spoiled the caterpillars’ appetite. I’m just saying.
Back in 2016, the American Medical Association recommended against cities installing LED lights containing high levels of blue, warning that it could inhibit the body’s production of melatonin, a hormone that helps regulate sleep. They noted that we are already subjected to too much blue light in the evening, coming from cell phone, laptops and TV’s. The lights could also make it harder for drivers to see and might disturb bird migration patterns. Well, maybe. But I wouldn’t lose any sleep over it.