in the video it equals the rad does to 2 minutes of flying. now most flights are an hour or more so which do you think the pilot or even the passengers have more to worry about, the scan or the actual flight?
Flying at 35,000 actually does expose you to a significant dose of radiation. As does tanning, both in the sun and in tanning machines.
Smaller but long term doses include, sitting infront of a tv, being at a computer, eating bananas (no joke), having granite countertops, smoking, or standing next to me (especially when I get cobalt-60 particles stuck in my skin).
The case for these scanners being unhealthy just isn't a viable threat.