Hmm. nursing unions are very strong in Mass, NJ,NY, DC, VA, and California..... and they get paid well....
Thinking of it another way, firefighters are not unionized in the Carolinas..... As a result, in SC, firefighters have some of the lowest wages for full time departments in the US. wages aren't as bad in NC for firefighters, but you aren't going to make as much money as you will in, say, Virginia. There are no union for EMS either, but is some places EMS does make more than firefighting.
NC and SC don't have unions, period. as a result, wages, especially in public safety are lower than in other parts of the country. Fire and PD also have higher turnover in the carolina's than in the NE (where I am from); and by turnover, I mean people leaving for other departments, not leaving for other career paths.