One general use backscatter scan radiation dose = 0.01 mrem
One day of natural background radiation = ~ 1 mrem (10 backscatter scans)
Average commercial airplane flight (one way) = 4 mrem (40 backscatter scans)
Typical chest x ray = 10 mrem (100 backscatter scans)
Typical abdominal x ray = 70 mrem (700 backscatter scans)
Annual maximum permission radiation dose limit for the public = 100 mrem (1,000 backscatter scans)
Annual maximum permissible radiation dose limit for radiation workers = 5,000 mrem (50,000 backscatter scans)