That looks like sea foam, we get that here in Venice sometimes after a big storm, I think it's partially caused by pollutants but I could be wrong. It doesn't look like the same thing as the cloud floating down the street is made of...
It does, but there's another film of it from that region where it looks more like a very loose ball of fiberglass insulation or something. It's definitely a foam of some kind, if it is legitimately falling out of the air like all of the completely unreputable Youtube channels claim then it's probably something that's being released into the air from some kind of manufacture and then forming a foam of some kind when it mixes with moisture in clouds.