NCRP 160

Question 1

what is NCRP 160 on?

Answer 1

Ionizing radiation exposure of the population of the US

Question 2

ubiquitous background radiation

Answer 2

 Internal, inhalation (Rn-222) – 2.3 mSv/y
 Internal, ingestion (C-14) – 0.3 mSv/y
 External, from space (cosmic rays) – 0.3 mSv/y
 External, terrestrial (U-238) – 0.2 mSv/y
 TOTAL = 3.11 mSv/year

Question 3

medical radiation exposure

Answer 3

 CT – 1.5 mSv/y
 Nuclear medicine – 0.8 mSv/y
 Interventional fluoro – 0.4 mSv/y
 Conventional radiography and fluoro – 0.3 mSv/y

Question 4

transatlantic flight dose

Answer 4

0.04 mSv

Question 5

diagnostic doses

Answer 5

• Dental x-ray: 0.005 mSv
• Chest x-ray: 0.1 mSv/image
• Abdominal x-ray: 0.7 mSv
• CT head scan: 2 mSv
• CT chest scan: 7 mSv
• PET or SPECT scan: ~3-18 mSv

Question 6

lowest dose that may cause symptoms of radiation sickness (nausea, vomiting) if received within 24 h

Answer 6

1 Sv

Question 7

lowest dose at which damage to organs/tissues have been observed following acute exposure?

Answer 7

100 mSv