radiation Flashcards
when were x rays discovered and who by
roentgen 1895
what did bequerel discover in 1896
radioactivity
when did pierre and marie curie discover the radioactive element of radium
1898
what are the laws of Bergonie and Tribondeau (1906)
stem cells are more sensitive
younger tissue is more sensitive
tissues with high metabolic activity are more sensitive
rapidly dividing cells more sensitive
what did muller show in 1927
radiation is mutagenic
where does radium accumulate
bones
what doesthe alpha particle emitter ra226 kill
osteoblasts and other cells required for bone maintenance
how does O2 increase killing effects of ionising radiation
leads to hydrolysisn of water (radiolysis) leading to free radicals
when was the atom bomb dropped on hiroshima
1945
what are the three main types of radiation
alpha
beta
x andgamma rays
what is exposure measured in
grays (Gy)
what do grays measre
amount of energy absorbed and released
what does one Sv equal
Gy x radiating factor
faster release of radiation is…
more damaging than slow
what measures rate of release when radiation travels through matter
Linear energy transfer
what is LET a function of
mass and charge
why does alpha have a greater LEt
more chance it will interact with molecules and deposit its energy
what are the sources of radiation
cosmic rays, solar rays, terrestrial radiation
what is the radioactive product of radium 226
radon 222
where is radon 222 found
rocks soil ground water
what form of radiation is mostly found in our bodies
potassium 40
what are anthropogenic sources of radiation
x rays
radioactive waste
accidents at nuclear power plants
when was the windscale incident
1957
when was three mile islan
1997
when was chernobyl
1986
when was fukushima
2011
what are the deterministic effects of radiation
radiation sickness, damage to skin and cateracts
what are the stochastic effects
genetic damage and cancers
why do high doses cause immediate death
damage to CNS
what is the cause of death from medium doses
damage to gi tract
how long does death occur after exposure to medium doses
few weeks
what are medium doses
10-50gy
what do low doses cause
radiation sickness
what are the symptoms of radiation sickness
nausea vomiting diarrhoea lethargy fever bleeding
why does fever occur
damage to cells–> cell lysis
how is radiation treated
blood transfusion
intravenous feeding
antibiotics
what are the effects of foetal exposure
mortality, malformations, mental retardation, reduced intelligence, childhood cancer
