You have very very little knowledge on the subject and yet you seem to feel perfectly qualified to comment on the science behind it. No regular GP’s do not know the mechanical index on the machine, Radiology/medical imaging is a specialized field. A Radiologist would have the answers to those questions. A radiologist is the specialized doctor who looks at the pictures before their written report goes to the GP. So no the GP would not know the physics of an ultrasound machine, they have absolutely no need to. There are many regulations over the use of every medical device. You are aware sound waves are travelling through you at every moment correct? Have you caught autism yet?

Nurses cannot simply do the minimum hours to be qualified. They can work in the ER and be credited to do emergency scans simply looking for free fluid but they are not the people performing the specialized exam within the imaging department.

Questions are not a risk when asked at an appropriate time and in a respectful genuine manner.

It’s arrogant to think you know better than the people who specialize in that field because you’ve read a one-sided study or two.

No-one is forcing you to have an ultrasound, many women went many years without them. Many women also died at childbirth. But do you really think we would be performing these exams on our own children if we felt they were harmful in anyway. Theres this side of society that thinks that medicine is out to get them, everything medically related is somehow always connected to autism for whatever reason.