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 By comparing the amounts of C-14 & C-12 in something, we can figure out how many half-lives have gone by since it died. 6 -1 7

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 Measure film thickness (by attenuation) Kill bacteria and spores in food and mail

Medical Use radioisotopes with short half-lives that are quickly eliminated from the body. Tracers in 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

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 High doses can cause illness & death Can cause mutations in DNA Disposal of waste esp. from nuclear power plants is difficult Fuel rods are a mix of many substances. Storage & transportation both problematic.