Questioning whether the federal government has the right to do something doesn't mean you don't believe government at any level has no right to do anything. There's a lot of stuff the federal government does which I don't think it should be able to do legally, but which state or local government should. Local effect pollution is one of these, although diffuse pollution should be handled federally. I guess you could handle pollution from Michigan affecting Pennsylvania by either PA entities (private or the state) suing MI entities (private or the state), such that MI makes it illegal to spread certain pollution across state borders.