radioactive tracers do constitute radioactive material. Stupd semantics. Ypu can choose to have a CT scan, and good for you: the scandal here is that experiments were performed without the children or their parents having an opportunity to give informed consent.

The amount of radiation in those tracers was no more than 0.15µSv. That's five times less than what you get by eating six bananas a day.

And I highly doubt that there was no consent beforehand. Perhaps there was excessive legalese or the parents were not notified of the tracers, but that doesn't constitute the assumption that no consent was given.

Yes, do you know what else constitutes a radioactive material?

A Banana

One of the highest amount of radioactivity in natural products.