Bottom pane was developed by Isao Hashimoto. The original video can be viewed here: https://www.youtube.com/watch?v=LLCF7vPanrY . This version shows the activity of tritium in precipitation as measured in Ottawa, Canada. Tritium is reported in "tritium units," equivalent to 0.118 becquerels per liter. Thanks to G. Jasechko for help creating this!
The limit for drinking water ranges from country to country. The investigative limit in the E. U. is ~850 T.U., and the drinking water limits in the U.S.A. and Canada are ~6,200 T. U. and ~60,000 T.U., respectively.