BTW, it's my understanding that acid rain is a localized issue and can be tracked down to a few or a single source in one area. For example an unscrubbed coal fired plant.
The biggest argument was the industrial north east. Think Pittsburgh to New York City. They said that the pollution from those cities was drifting toward South East Canadian forests. Then it would rain and the acid would destroy the Canadian trees.
Also a bunch of stuff on old statues in Wash DC being eroded from acid rain.