ppt 1 Flashcards
what is rad bio
describing and explaining the changes that radiation produces in biological cells and organisms
ionizing radiation such as x rays may produce harmful effects on living organisms such as…
-gross or microscopic
-lethal or non-lethal
-immediate or delayed
agricultural use of radiation…
-sterilize male pest insects and release them into wild population to decrease population growth
-irradiate grains, spices, fruits, milk etc to preserve foods and increase their shelf life
industrial use of radiation
-scientific research
-electrical power generation
-instrument and guages to measure thickness and density of material
medical use of radiation…
-sterilization of medical equipment
-use of xray for dx
-use of radioisotopes for dx
-use of xrays and gamma rays for treating cx
-use of Ab-radioisotope conjugates for treating cx (radioimmunotherapy)
what is ionizing radiation
-ion charged particles
-ionization= separation of orbital electrons from an atom
-ionizing radiation= enough energy to ionize the matter through which it passes
-mechanism in which human tissue is damaged
what happens when an ion sharing electrons by 2 atoms forms a molecular bond…
that bond is broken and thus the molecule falls apart
activity is
measure of how much radioactivity a radioactive material emits, measured in disintegrations/sec
measurements of activity
curies, becquerel
1 Ci=
3.7 x 10^10 disintegrations/sec
1 Becquerel=
1 disintegreations/sec
1 Ci=
3.7 x 10^10 Bq
exposure is…
measure of how many ion pairs are formed in a given volume of air when exposed to radiation.
what is exposure not
NOT meausre of energy absorbed or dose. NOT relate to amount of biological affetcs on human body
roentgen is the
amount of gamma or xrays which produce ions carrying one electrostatic unit of hcarge in one cm3 of dry air (usually expressed in R/min or R/hr
radiation absorbed dose (rad) is a
unit of meausring absorbed dose in any material (energy being depositied by radiation)
-applies to all radiation
radiation absorbed dose )rad) does not
-not take into acount potential effects of diff types of rad on body
-not measure of risk to body
equivalent dose measures
dose in a person in remr
rem stands for
roentgen equivalent man