Where is the aluminum and heavy metals that rain on us come from? Meteors?
Here. Not interested in your opinion on this subject until you do research yourself. This one isn’t the best, but it’ll have to do for now.
https://www.youtube.com/watch?v=Fs5NPoWB8-E
Pollution into the waters, then up into the clouds, then down on your head as rain, I would assume is the cycle.