Anaxagoras wrote: ↑
Fri Feb 28, 2020 6:35 am
robinson wrote: ↑
Thu Feb 27, 2020 5:15 pm
The half-life of uranium-238 is about 4.47 billion years
The longer the half life, the less radioactive.
Anax wrote: I think isotopes with shorter half lives (but not too short) tend to be the dangerous ones.
Dangerous only if handled improperly. The short lived ones tend to be the most valuable ,useful, across several industrial and scientific applications, mainly medical.
Those whose half-life is measured in seconds are not too useful, but most everything else is.
https://www.world-nuclear.org/informati ... icine.aspx
Bismuth-213 (half-life: 46 min):
Used for targeted alpha therapy (TAT), especially cancers, as it has a high energy (8.4 MeV).
Caesium-131 (9.7 d):
Used for brachytherapy, emits soft x-rays.
Caesium-137 (30 yr):
Used for low-intensity sterilisation of blood.
Chromium-51 (28 d):
Used to label red blood cells for monitoring, and to quantify gastro-intestinal protein loss or bleeding.
Cobalt-60 (5.27 yr):
Formerly used for external beam radiotherapy, now almost universally used for sterilising. High-specific-activity (HSA) Co-60 is used for brain cancer treatment.
Dysprosium-165 (2 h):
Used as an aggregated hydroxide for synovectomy treatment of arthritis.
Erbium-169 (9.4 d):
Used for relieving arthritis pain in synovial joints.
Holmium-166 (26 h):
Being developed for diagnosis and treatment of liver tumours.
Iodine-125 (60 d):
Used in cancer brachytherapy (prostate and brain), also diagnostically to evaluate the filtration rate of kidneys and to diagnose deep vein thrombosis in the leg. It is also widely used in radioimmuno-assays to show the presence of hormones in tiny quantities.
Iodine-131 (8 d)*:
Widely used in treating thyroid cancer and in imaging the thyroid; also in diagnosis of abnormal liver function, renal (kidney) blood flow, and urinary tract obstruction. A strong gamma emitter, but used for beta therapy.
Iridium-192 (74 d): Supplied in wire form for use as an internal radiotherapy source for cancer treatment (used then removed), e.g. for prostate cancer. Strong beta emitter for high dose-rate brachytherapy.
Iron-59 (46 d):
Used in studies of iron metabolism in the spleen.
Lead-212 (10.6 h):
Used in TAT for cancers or alpha radioimmunotherapy, with decay products Bi-212 (1 h) and Po-212 delivering the alpha particles. Used especially for melanoma, breast cancer and ovarian cancer. Demand is increasing.
Lutetium-177 (6.7 d):
Lu-177 is increasingly important as it emits just enough gamma for imaging while the beta radiation does the therapy on small (eg endocrine) tumours. Its half-life is long enough to allow sophisticated preparation for use. It is usually produced by neutron activation of natural or enriched lutetium-176 targets.
Molybdenum-99 (66 h)*:
Used as the 'parent' in a generator to produce technetium-99m.
Palladium-103 (17 d):
Used to make brachytherapy permanent implant seeds for early stage prostate cancer. Emits soft x-rays.
Phosphorus-32 (14 d):
Used in the treatment of polycythemia vera (excess red blood cells). Beta emitter.
Potassium-42 (12 h):
Used for the determination of exchangeable potassium in coronary blood flow.
Radium-223 (11.4 d):
Used for TAT brachytherapy, lodges in bone, emits soft X-rays.
Rhenium-186 (3.8 d):
Used for pain relief in bone cancer. Beta emitter with weak gamma for imaging.
Rhenium-188 (17 h):
Used to beta irradiate coronary arteries from an angioplasty balloon.
Samarium-153 (47 h):
Sm-153 is very effective in relieving the pain of secondary cancers lodged in the bone, sold as Quadramet. Also very effective for prostate and breast cancer. Beta emitter.
Selenium-75 (120 d):
Used in the form of seleno-methionine to study the production of digestive enzymes.
Sodium-24 (15 h):
For studies of electrolytes within the body.
Strontium-89 (50 d)*:
Very effective in reducing the pain of prostate and bone cancer. Beta emitter.
Technetium-99m (6 h):
Used in to image the skeleton and heart muscle in particular, but also for brain, thyroid, lungs (perfusion and ventilation), liver, spleen, kidney (structure and filtration rate), gall bladder, bone marrow, salivary and lacrimal glands, heart blood pool, infection, and numerous specialised medical studies. Produced from Mo-99 in a generator. The most common radioisotope for diagnosis, accounting for over 80% of scans.
Thorium-227 (18.7 d):
Used for TAT, decays to Ra-223.
Xenon-133 (5 d)*:
Used for pulmonary (lung) ventilation studies.
Ytterbium-169 (32 d):
Used for cerebrospinal fluid studies in the brain.
Ytterbium-177 (1.9 h):
Progenitor of Lu-177.
Yttrium-90 (64 h)*:
Used for cancer brachytherapy and as silicate colloid for the relieving the pain of arthritis in larger synovial joints. Pure beta emitter and of growing significance in therapy, especially liver cancer.
Radioisotopes of gold and ruthenium are also used in brachytherapy.
I had an intravenous Technetium-99m
cocktail just last week!
In roughly two months, after my first two rounds of chemo and removal of my bladder,, I'm still left with the metastasized lymphoma as a result of the original cancer. It used to be that they would remove the cancerous lymph nodes grossly through surgery, the more you have, the more grossly it becomes (I have 6 of them, currently, very gross!). It is extremely
invasive. Instead, I will most likely undergo radioimmunotherapy (RIT).
https://www.radiologyinfo.org/en/info.c ... dio-immuno
In RIT, a monoclonal antibody is paired with a radioactive material, or radiotracer. When injected into your bloodstream, the radiation-linked monoclonal antibody, or agent, travels to and binds to cancer cells, allowing a high dose of radiation to be delivered directly to the tumor. The agent used today isYttrium-90Ibritumomab Tiuxetan
So rather than cutting up my guts and legs to get to the problem lymph nodes, the worst that will happen is short-term low fever and chills as a side effect of the RIT.
Take that, nuclear atheists!
I'd be comfortable saying that the number of lives these isotopes have saved has dwarfed the lives lost by all nuclear incidents, accidental or otherwise.
https://en.wikipedia.org/wiki/Atomic_bo ... d_Nagasaki
The acute effects of the atomic bombings killed between 90,000 and 146,000 people in Hiroshima and 39,000 and 80,000 people in Nagasaki
Tens of millions of CT scans are performed every year.