There are two types of whole body security scanners at airports which are very different than the baggage scanners. Millimeter Wave Scanners use radio waves which are not ionizing (i.e. do not induce cancer). Backscatter Wave Scanners use very weak x-rays at a dose of less than 10 microrem per scan (0.0001 mSv)19.

For comparison it would take;
80 airport security scans to equal 1 day of natural background radiation
200 airport security scans to equal the radiation from a 7 hour flight
1000 airport security scans to equal one chest x-ray