Transition Block C - Radiology Online Tutorials Flashcards
What element provides on average 50% of the annual radiation to a person from the UK? Which element decay series forms this element t one point? The stable atom at the end of this elements decay series is lead-210
Radon provide an average of 50% of the annual radiation to a person from the UK This is element is a radioactive gas and one member of the uranium decay series
Following nuclear accidents or nuclear weapons testing, radionucleotides began to be more commonly found in the food we eat however in very low doses What radionucleotides accumulated in milk and meat after these incidents?
Iodine-131 accumulated in milk Caesium-137 accumulated in meat
Where are the most radio-sensitive cells in the skin found? What is the earliest effect of radiation to the skin seen as?
The most radiosensitive cells in the skin are found in the basal stratum of the epidermis The earliest effect of radiation to the skin is seen as erythema
The effects of radiation on humans can be split into two categories Deterministic effects / tissue reactions or Stochastic effects What do each of these mean?
Deterministic effects / tissue reactions result from high doses and occur within hours, days or weeks of exposure Stochastic effects are not apparent until many years after the exposure if they occur at all
What is the annual whole body dose limit set to for radiation workers set to to limit the stochastic effects of radiation? What is the annual dose limit for the lens of the eye set to for radiation workers set to to limit the risk of cataracts? What is the annual dose limit for single organs or extremities set to for radiation workers set to to limit the deterministic effects of radiation?
Annual whole body dose limit is set to 20mSv for radiation workers Annual dose limit for the lens of the eye is set to 150mSv for radiation workers to limit the risk of cataracts Annual dose limit for single organ extremities is set to 500mSv for radiation workers to avoid deterministic effects
Regarding stochastic or non-deterministic effects of radiation: Select true or false * A. Effects only occur above a threshold dose * B. The chance of the effect occurring increases with dose * C. The severity of the effect varies with dose * D. Leukaemia is an example of a stochastic effect * E. Loss of fertility is an example of a stochastic effect
A - False - no threshold dose because a single ionisation can damage a DNA molecule B - True C - False D - True E - False - this is a deterministic effects
Concerning deterministic tissue reactions: Select true or false for each of the following statements. A. Effects only occur above a threshold dose B. The likelihood of the effect occurring increases with dose C. The severity of the effect increases with dose D. Skin cancer is an example of a deterministic effect E. Cataract formation is an example of a deterministic effect
A - True B - True C - True D - False - example of a stochastic effects E - True
A link between organ dose and increased cancer incidence has been established at radiation doses above what?
A link between organ dose and increased cancer incidence has been established at radiation doses above 100-200mSv
How much will doubling your distance from the radiation source reduce the exposure from the radiation?
Doubling your distance from the radiation dose will decrease exposure by a factor of 4
What is the annual whole body dose limit set to for radiation trainees below 18 to limit the stochastic effects of radiation? What is the annual dose limit for the lens of the eye set to for radiation trainees below 18 to limit the risk of cataracts? What is the annual dose limit for single organs or extremities set to for radiation trainees below 18 to limit the deterministic effects of radiation?
Whole body dose limit for radiation worker trainees below 18 - 6mSv per year Lens of the eye limit for radiation worker trainees below 18 - 50mSv per year Single organs or extremities for radiation worker trainees below 18 - 150mSv per year
