Residents of St. Petersburg, Russia, are dealing with snow, which is not unusual for the city, but the snow that feel on Tuesday was strangely blue. Parents were apprehensive about letting children play in it because they would be tempted to taste it. Blue snow fell a couple of years ago in Chelyabinsk, in the eastern part of Russia, but that phenomenon was traced back to some blue Easter egg dye that a factory had spilled and then forget to report. Samples of the St.Petersburg snow were taken to laboratories for analysis.
Non-experts noted two things: the chemicals most likely to cause a blue stain are cobalt or methylene blue, also known as methylthioninium chloride, a substance used to treat methemoglobinemia, a blood condition that usually caused – ironically — by exposure to a drug or chemical. It’s ironic in this case because the locals also noticed that the blue snow coincided with the demolition of the nearby Chemist-Pharmaceutical Plant No. 1.
All together now: “Ah-ha!”