@sueinmn You hit the nail on its head! ".....and the group(s) that support it so fervently don't have hard data to show NTM grows on equipment so quickly as to pose a real danger..."

Precisely, their studies are strictly theoretical rather than empirical. They failed step #4.

We all studied the scientific method in grade school:
1. Ask a question – What do you want to find out?
2. Do background research – Learn what is already known.
3. Form a hypothesis – Make an educated guess or prediction.
4. Test the hypothesis – Do an experiment or collect data.
5. Analyze the results – Look at what the data show.
6. Draw a conclusion – Decide whether your hypothesis was right or wrong.
7. Share results – Report what you found so others can learn or repeat it.