Toxicología - Radiaciones

25-0025 Toxicología Laboral

SESSION 10 – IONISING
RADIATION

Introduction
 Matter, molecule, atom, protons, neutrons
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

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and electrons
Nucleus
Electronic cloud
Stable andunstable isotopes
Energy release

Introduction

Introduction
 At the molecular level, radioactive 210Pb has the

same toxicity as its stable counterpart 207Pb
 This fact, of course, formsthe rationale for the
use of radioisotopes as tracers in biochemistry,
physiology, and ecology
 With the assumption that the radioactive
element behaves in the same way as its stable
isotopes, thepassage and the dynamics of
numerous substances through various
components of the ecosystem can be traced

Concepts
 Natural ionising radiation takes

three principal forms:


Alphaparticles. Alpha decay
produces alpha particles, which
consist of two neutrons and two
protons and carry a +2 charge, the
equivalent of a helium nucleus
 Although alpha particles have very
highionizing capability, their
energy is quickly dissipated in their
passage through matter
 They will only travel through a few
centimeters of air and will be
stopped by a piece of paper or the
outerepithelium of an organism.
Alpha emitters are of concern only
if taken into the body by inhalation
or ingestion

Concepts


Natural ionising radiation takes
three principal forms:
Beta particles. Beta decay produces
beta particles, which are negatively
charged electrons formed when an
excess of neutrons in the nucleon
causes a neutron to be changed into a
proton. If nuclearimbalance results in
an excess of protons in the nucleon, the
emitted particle is the positively
charged equivalent of an electron
known as a positron. This causes a
proton to be changed to aneutron.
Alternatively, the proton may be
converted to a neutron with the
capture of a satellite electron, a process
known as electron capture. b emitters
vary widely in their energy output,...