Transcript Benefits & Dangers of: Radioisotopes

Benefits & Dangers of:
Radioisotopes
Dating (not that kind)
C-14 is used to date organic (previously living)
materials
Living organisms incorporate C-14 into their
structure, along with C-12
C-14 decays with a known half-life
14C  14N + 0
-1
6
7
comparing amounts of C-14 & C-12 can figure
how many half-lives have gone by since it died
– Helps determine age of substance
ROCKS
U-238 decays to Pb-206 (many steps)
Over time:
– amount of U  and amount of Pb 
– Scientists use the ratio of U-238 to Pb-206 to
date rocks
Chemical Tracers
Able to detect radioactive materials and
their decay products
Tracer = any radioisotope used to follow
the path of material in a system
– P-31 used to determine P uptake in a plant
– C-14 used to map C in metabolic processes
– C-14 used to map organic molecules and
figure out reaction mechanisms
Industrial Applications
Kill bacteria and spores in food and mail
Medical
Use radioisotopes with short half-lives that
are quickly eliminated from the body
– Tracers used for:
medical diagnosis
Treatment of cancer
I-131: Diagnosis & treatment of thyroid
disorders
Co-60: gamma emitter
– Used to kill cancerous tumors
Medical
Co-60 and Cs-137 used to destroy anthrax
bacilli
Co-60 used to kill bacteria in foods
Tc-99 treatment of brain cancer
Nuclear Power Plants
Used as a fuel source to generate electricity
No contributions to greenhouse gases
No mercury contamination of atmosphere
Radiation Risks
Can damage normal tissue
Can cause mutations in DNA
High doses can cause illness & death
Disposal of radioactive waste is difficult
– Fuel rods are a mix of many substances
– Storage & transportation both problematic