Question

D. What is the typical background radiation we are exposed to? What additional exposure would we get from a chest x-ray? A CT scan of the torso? A coast-to-coast flight? A year of living in Denver, CO? Approximate or representative values are sufficient.
Please stay within the same unit system (i.e., choose either Sievert or rem) for easier comparison in (F).

E. Before flat-screen TV sets became widespread, color TV sets used huge cathode ray tubes (CRT). To generate TV images with sufficient brightness, the electron beam was accelerated with an appreciably high voltage. What were typical acceleration voltages in those TV sets? Would they represent an x-ray hazard? Provide a reason for your answer!

Note: Provide the sources for your answers (D) and (E) as well!

Note also: In (E), a government mandate that the x-ray dose had to remain below allowed limits is not a valid reason, because a government mandate is not an engineering solution -- not by a far shot.

Answer 1

D) Background radiation is defined as the level of ionizing radiation existing in a particular location. It can be natural and man made. Natural sources include radioactivity from natural radioactive materials, cosmic radiations etc. Man made sources include x-rays from medical fields, fallouts from nuclear weapon testings, nuclear accidents etc. Background radiation from natural sources is about 2.40 mSv and from man made is 0.61 mSv. Overall there is approximately 3.01 mSv.

The amount of background radiation is less in chest x-rays. There is slight chance for cancer from excessive exposure to radiation. Avoid pregnant women , children from cheat x-rays. Chest x ray emits approximately 0.1 mSv background radiation.

CT scan uses x-rays. It will damage DNA which leads to cancer. CT scan can emit 1-20 mSv of radiation.

On an average 3-5 micro Sv of radiation per hour is experienced during flying time. It varies from route and solar whether. Higher doses are from flying in poles.

E) Typical number for voltage for color TV during old time was 11000 volts DC. But color TV using 25000 volts DC was also present.

CRT from TV and computers are one of the main e-waste. These contain toxic materials like lead, cadmium etc. CRT emit small amount of x-ray due to bombardment of electron beam with walls. It emits 0.5 mR/h at a distance of 2 inch from external surface.