I don`t have any information on these, but any information you do get on them I would be interested in knowing the source. I have yet to see anything official from SSI, PADI, or any other agency outlining official doctrine of a "public safety diver" course.
Genrerally from what I`ve seen there is no "true" public safety diver course. They seem to be a compilation of coursework/specialties that fit the needs of the specific department. Unless I am incorrect, the public safety classification comes with the emergency services description in most cases.