TY  - CHAP
M1  - Book, Section
TI  - Chapter 25. Toxic Effects of Radiation and Radioactive Materials
A1  - Harley, Naomi H.
A2  - Klaassen, Curtis D.
A2  - Watkins, John B.
Y1  - 2010
N1  - 
T2  - Casarett & Doull's Essentials of Toxicology, 2e
AB  - The  four  main  types  of  radiation  are  due  to  alpha  particles,  electrons  (negatively  charged  beta  particles  or  positively  charged  positrons),  gamma  rays,  and  x-rays.Alpha  particles  are  helium  nuclei  (consisting  of  two  protons  and  two  neutrons),  with  a  charge  of  +2,  that  are  ejected  from  the  nucleus  of  an  atom.Beta  particle  decay  occurs  when  a  neutron  in  the  nucleus  of  an  element  is  effectively  transformed  into  a  proton  and  an  electron,  which  is  ejected.Gamma-ray  emission  is  not  a  primary  process  except  in  rare  instances,  but  it  occurs  in  combination  with  alpha,  beta,  or  positron  emission  or  electron  capture.  Whenever  the  ejected  particle  does  not  utilize  all  the  available  energy  for  decay,  the  excess  energy  is  released  by  the  nucleus  as  photon  or  gamma-ray  emission  coincident  with  the  ejection  of  the  particle.Ionizing  radiation,  by  definition,  loses  energy  when  passing  through  matter  by  producing  ion  pairs  (an  electron  and  a  positively  charged  atom  residue).Radiation  may  deposit  energy  directly  in  DNA  (direct  effect)  or  may  ionize  other  molecules  closely  associated  with  DNA,  hydrogen,  or  oxygen,  to  form  free  radicals  that  can  damage  DNA  (indirect  effect).  
SN  - 
PB  - The McGraw-Hill Companies
CY  - New York, NY
Y2  - 2024/04/25
UR  - accesspharmacy.mhmedical.com/content.aspx?aid=6486016
ER  -