Test 1- Introduction to radiation safety

R:

Energy in coulombs/kg deposited in air by photons only

rad:

Is approximately equal to a Roentgen for low energy 𝛾 and x-rays, and it accounts for deposited (absorbed) energy (dose) as it travels through matter

rem:

Measure of absorbed dose corrected for emission type (particle vs photon) and organ recieving the radiation, to account for biologic damage

Gy:

This S.I. unit is for absorbed radiation dose is measured in J/Kg

Sv:

This S.I. unit for absorbed radiation dose comes from a Gray and is multiplied by a weighting factor that takes into account the type of radiation (particle vs photon) and organ recieving the radiation, to account for biologic damage

Film Badge dosimeter:

It is the least durable (short shelf life, easily damage by water)

Optically stimulated luminescence (OSL) dosimeter:

This dosimeter has the highest sensitivity to measuring radiation

Thermoluminescent dosimeter (TLD):

Is measured by heating the device and is extremely susceptible to being damaged by putting in the laundry

Pocket Ion Chamber dosimeter:

Although it provides real time measurement, its poor inaccuracy means it can’t be used for legal record

What are the maximum 1 year (unless stated otherwise)  radiation dose limits (in mR) for each of the following?

An x-ray technologist over a 1 year period of time:

5000 mrem

What are the maximum 1 year (unless stated otherwise)  radiation dose limits (in mR) for each of the following?

A patient transporter/holder who works solely in radiology and nuclear medicine over any given 3 month period:

3000 mrem

What are the maximum 1 year (unless stated otherwise)  radiation dose limits (in mR) for each of the following?

The annual hand exposure to a nuclear medicine worker:

50000 mrem

What are the maximum 1 year (unless stated otherwise)  radiation dose limits (in mR) for each of the following?

A payroll accountant who works for the hospital:

100 mrem

What are the maximum 1 year (unless stated otherwise)  radiation dose limits (in mR) for each of the following?

The exposure to the lens of the eye of a radiologist performing fluoroscopy:

15000 mrem

What are the maximum 1 year (unless stated otherwise)  radiation dose limits (in mR) for each of the following?

A nuclear medicine technologist who has declared her pregnancy and is in her first month of gestation (limit for the entire gestation period):

500 mrem

This is considered to be the number 1 source of man made ionizing radiation exposure to the general public:

Medical Procedures

In Missouri, a typical member of the public receives how much dose per year from background radiation? 

300-400 mrem

Which of the following government organizations regulate radiation in some way?

All of these in some way

This organizations goal is to increase awareness and promote radiation protection when imaging children:

Image Gently

For radiation workers receiving minimal amounts of radiation, what is the longest period of time that is acceptable for them to wait before exchanging dosimeters?

Every 3 Months (Quarterly)

An x-ray technologist trips and injures their arm while at work and must receive x-rays to rule out a fracture. Since this occurred at work, the technologist should continue to wear their dosimetry badges while they receive their x-rays.

False

A nuclear medicine technologist who is 36 years old has been working in a high radiation lab for the last 12 years. Each year they have been in their job they have received 3 rem which has given them a cumulative lifetime exposure of 36 rem. As they turn 37, three months later, upon reviewing their records you discover that they now have a cumulative lifetime exposure of 38 rem. Which of the following statements is accurate for the rest of the year:

Action is mandatory and they must be limited to 1 rem over the next 12 months

Just like the last question, a nuclear medicine technologist who is 36 years old has been working in a high radiation lab for the last 12 years. Each year they have been in their job they have received 3 rem which has given them a cumulative lifetime exposure of 36 rem. As they turn 37, three months later, upon reviewing their records you discover that they now have a cumulative lifetime exposure of 38 rem. Which of the following statements is accurate:

Even though the technologist's exposure is high, they have never exceeded their prospective annual limit

How long can an radiation worker be allowed to go in to a high radiation area without exceeding the exposure limits to clean up a major radioactive spill if the ambient dose rate is 2000 mR/hr?

Hint: Think about both annual and quarterly limits

1.5 hours

What does A.L.A.R.A. stand for?

As low as reasonably achievable

When should an employee be assigned a radiation dosimetry badge?

If their assigned duties may result in them exceeding 10% of the annual limt of a radiation worker

How often should you do area surveys with a geiger counter in places where radioactive drugs are used or given to patients?

Daily

How often should you do removable contamination surveys with wipes in places where radioactive waste is stored?

Weekly

Who were the "Radium Girls"?

A group of women hired in the early 1900's to paint watch faces who tragically died from ingestion of Radium

The attenuation coefficient for a new and cheaper graphite material used in shielding 100 kV x-rays is 0.1385 mm^-1.

 

What is the half value layer for this new graphite material when using 100 kV x-rays?

5 mm

You have been monitoring your monthly radiation exposure readings and you have noticed they have been high. Normally when you are assisting in the special procedures room during angiography work, you have been standing roughly 3 feet away from the x-ray tube. You bring a radiation detector into the room and discover that the radiation levels at that distance are 15 mR/hr.

 

What would you expect the radiation levels to be if you step back to 6 feet away from the x-ray tube?

3.75 mR/hr

Just like the last question, you have been monitoring your monthly radiation exposure readings and you have noticed they have been high. Normally when you are assisting in the special procedures room during angiography work, you have been standing roughly 3 feet away from the x-ray tube. You bring a radiation detector into the room and discover that the radiation levels at that distance are 15 mR/hr.

 

How far away from the x-ray tube would you need to stand to have the exposure reduced to roughly 1 mR/hr?

11.6 ft

As a radiology manager you are presented the opportunity to buy replacement lead aprons at a discount price. The new aprons are 2.3 mm (0.23 cm) thick instead of 1.7 mm (0.17 cm) thick for the same price. In general, your technologists, in the fluoroscopy lab, when wearing the old aprons (that are 0.17 cm thick) are getting roughly 30 mR a month under these aprons. What radiation exposure do you anticipate they will be getting after the switch (lead/rubber mixture has a HVL =0.3 cm and the µ = 2.31 cm^-1 and the new aprons are 0.23 cm thick and the old were 0.17 cm thick)?

26.1 mR/month