Flashcards in Exam 1.5: Radiation Biology, Safety, Infection Control Deck (45)
What are the three effects of radiation on atoms and molecules
Breakage of Molecular Bonds
What happens to an electron when it is excited by an xray photon?
It vibrates before returning to its normal state, releasing the energy stored from the impact as heat or light
How could radiation create an ion pair?
A high energy photon can impact an atom and eject an orbital electron creating a positive ion and a free electron....an ion pair
Why is molecular bond breakage the worst type of radiation damage?
It renders the molecules useless and can kill the organelle, which might lead to cell death
What free radicals are created via radiolysis of water?
OH* and H*esi
Can then react with water to form
Besides water, what other common biological molecules can be turned into free radicals when hit with radiation
What is a DIRECT effect of radiation exposure?
Ionization energy is placed directly into critical molecules within the cell
What is the critical biomolecule?
What is the INDIRECT effect of radiation exposure?
The water in the cell is radiolysed creating free radicals and toxic chemicals (H2O2) that then damage critical molecules like DNA and proteins
What is the period between the radiation exposure and the damage incurred by indirect effects?
What are some health problems caused by the accumulative effects of radiation exposure?
What factors of the radiation influence the radiobiological effects of radiation exposure?
Type of Radiation
LET (Linear Energy Transfer)
Penetrating ability/Quality of Beam
Local area v. Entire body
How do Alpha particles and X-rays compare in terms of LET?
Alpha particles have a High LET
X rays have a low LET
What host factors influence the radiobiological effects of radiation exposure
Type of Tissue
Rate of cell division
Somatic Tissue vs. Genetic Tissues
What are the worst tissue cells to get hit with radiation?
What are the "best" tissue cells to get hit with radiation?
What are 4 Deterministic Effects
Erythema and Skin Ulcers
Epilation (Hair falls out by the roots)
What is the term for genetic effects of radiation
What are the 4 Total Body Irradiation Syndromes
Bone Marrow Syndrome
Which syndrome requires a threshold of 50+ Grays?
CNS (Neurons are able to take a lot of radiation)
What syndrome is imparted with 10-50 Grays
No cases of survival with doses of 10+ Grays
How much radiation is required to acquire Bone Marrow Syndrome
What percent of the average americans annual radiation comes from medical x-rays?
What percent of the average american's annual radiation comes from radon in the ground?
How much radiation is the average american exposed to in one year (in microSieverts)
How many microsieverts is in one Panoramic Radiograph
What are the chances of increased cancer risk from a dental x-ray?
1 in 1 Million Billion
What is the difference between exposure and dose?
Exposure (R) is the amount of radiation coming out of the machine
Dose is the amount of radiation that was absorbed by a unit mass of tissue
What do you need to multiply the dose by to get a effective dose measurement?
The quality of the beam.
Xray multiplier = 1
Neutrons = 5
Alpha Particles = 25