It was just an expression meaning "we don't have that great a handle" either on how much Western countries actually pollute.

As proven in the examples mentioned in subsequent comments.

It's impossible to say without some type of dedicated study focused specifically on the question, but my sense is that those examples are rather extraordinary exceptions, and not the rule.

Color me unsurprised that the Mafia is breaking laws; there are also vanishingly few organizations like the Mafia in the developed West.