Benefits & Dangers of: Radioisotopes

Dating (not that kind) C-14 used to date organic (previously living) materials living organisms incorporate C-14 into their structure, along with C-12 C-14 decays with known half-life 146C  147N + 0-1 comparing ratios of 14C: 12C figure how many half-lives gone by since died helps determine age of substance

ROCKS U-238 decays to Pb-206 (manysteps) over time: amount U  & amount Pb  - scientists compare ratio of U-238 to Pb-206 to date rocks

Chemical Tracers detect radioactive materials & decay products tracer: radioisotope used to follow path of material in system P-31: determines P uptake in plants C-14: maps C in metabolic processes C-14: maps organic molecules & figures out reaction mechanisms

Industrial Applications tracers kill bacteria and spores in food and mail Medical Applications Co-60 & Cs-137: destroys anthrax bacilli Co-60: kills bacteria in foods Tc-99: treatment of brain cancer

Medical Applications radioisotopes with short half-lives (quickly eliminated from body) for medical diagnosis diagnose & treat cancers I-131: diagnosis & treat thyroid disorders Co-60: gamma emitter used to kill cancerous tumors

Power Plants radioactivity used as fuel source to generate electricity advantages: no contributions to greenhouse gases no mercury contamination of atmosphere

Radiation Risks damage normal tissue high doses can cause illness & death cause DNA mutations disposal of waste is difficult especially from nuclear power plants fuel rods are mix of many radioactive substances storage & transportation both problematic