What I meant was that back in the old days, people didn't bother as much to recycle things, so lead batteries ended up thrown away in the nature. Of course today we recycle a lot more, so it would be less of a problem.
Where I live (european country) people used to throw away things in a big dump and then it would be burned or something, but now you have to separate things. I don't have any evidence of it though. Maybe they were recycling it themselves for all this time!