Translate the following English sentence to French:
"We are pleased, however, that the Greens have achieved a great breakthrough when it comes to emissions of dangerous substances, which now have to be identified on the list of priority substances."
Nous sommes toutefois heureux que les verts aient réussi à s' imposer en ce qui concerne l' émission des substances dangereuses, qui doivent maintenant être inscrites sur la liste des substances prioritaires.