5. Uses of Radioactive-isotopes emitting alpha, beta, positron or gamma ionising radiation
Doc Brown's Chemistry - KS4 science GCSE/IGCSE Physics and Chemistry Revision Notes
IDEAS: These revision notes on how to use ionising radiation in a variety of industrial, medical and environmental situations should help with GCSE/IGCSE/O Level physics courses and A/AS level physics courses. How do we use radioisotopes for? How can we use alpha particle radiation, beta particle radiation and gamma radiation rays? How do we relate the use of ionising radiation with its physical properties e.g. it penetration into material or the half-life of the radioactive source. Gamma and beta emitting radioisotopes are extensively used in medical diagnostic and treatment procedures. Radioisotopes are used in a variety of ways in industry to improve productivity and, in some cases, to gain information that cannot be obtained in any other way. Radioisotopes are used in radiography, gauging applications and mineral analysis. Short-lived radioisotopes are used to trace flow and fluid mixing systems. Gamma ray sterilisation procedures are used in preparing medical supplies packaged food preservation. How does PET scanning work? The world of medical physics uses various diagnostic techniques to investigate blood flow and metabolic functions.
But to fully understand this page you specifically need to know
(i) Relative penetrating power of the ionising radiations: gamma > beta- > alpha
(ii) The half-life of a radioisotope is the time taken for half of the radioactive atoms of a specific isotope to decay
and (iii) an understanding of nuclear equations is assumed, refer to section 7.
An introduction to the use of radioisotopes and nuclear radiation in medicine
The medical uses of nuclear radiations and radioisotopes are expanding all the time as technology improves and hopefully become cheaper so more patients can be diagnosed and treated. However, as with the 'humble' X-ray, there are serious health and safety issues that must be addressed. You have to weigh the possible positive outcomes versus the possible dangers!
Ionisation caused by radiation can kill cells completely or damage it so it can't divide, whichever happens, the effect is damage to tissue. Although harmful in itself, if the radiation damages and alters the genetic material in the cell (DNA) it can cause mutations. Some mutations can cause the cell to divide and multiply out of control producing cancer tumours. Hence the need in any ionising radiation treatment to limit the patient's exposure to it.
Like it or not, any extra exposure to nuclear radiation or X-rays increases the risk of tissue damage and cancer. In any radiation treatment or diagnostic procedure the patient should be given the lowest possible effective dose and experience the shortest possible exposure time. Lead shielding can be used to protect areas of the body not being treated and wherever possible to radiation focussed onto the part of the body under examination or treatment.
What goes for patients must also apply to medical personnel carrying out the treatment or examinations using potentially harmful nuclear radiation procedures. Examples of protective measures include ...
Nuclear radiation sources can be used internally and externally to treat cancer tumours.
Decisions: Generally speaking internal treatments have no side-effects other than maybe discomfort from the implant procedure, but external treatments like radiotherapy can have both short-term and long-term effects which may be immediate or show up months or years later.
Developing new treatments
Some examples of radioactive isotopes used in medicine
Note: (i) (t½ = half-life) and (ii) some of these examples are discussed in more detail in the next sections 5a-5d.
Technetium-99 (t½ = 6 hours): 99Tc, a beta emitter 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 lachrymal glands, heart blood pool, infection and numerous specialised medical studies.
Cobalt-60 (10.5 mins/5.29 years): 60Co, beta/gamma emitter once used for external beam radiotherapy.
Iodine-123 (t½ = 13 hours): 12353I Increasingly used for diagnosis of thyroid function, it is a gamma emitter without the beta radiation of I-131.
Iodine-125 (t½ = 60 days): 125I, a gamma emitter used to diagnostically 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 (t½ = 8 days): 131I a beta and gamma emitter, is widely used in treating thyroid cancer and in imaging the thyroid gland also in diagnosis of abnormal liver function, renal (kidney) blood flow and urinary tract obstruction.
Iridium-192 (t½ = 74 days): 192Ir, a gamma emitter can be supplied in wire form for use as an internal radiotherapy source for cancer treatment and after use it can removed.
Potassium-42 (t½ = 12 hours): 42K, a beta minus and gamma emitter used for the determination of exchangeable potassium in coronary blood flow.
Sodium-24 (t½ = 15 hours): 24Na, is a beta- and gamma emitter is used to study of electrolytes in the body.
Xenon-133 (t½ = 5 days): 13354Xe, a beta- and gamma emitting gas used for pulmonary (lung) ventilation studies.
Krypton-81 (t½ = 13 seconds) made from Rubidium-81 (t½ = 4.6 hours), 81Kr gas provides images of pulmonary ventilation in the lung, e.g. in asthmatic patients, and provides early diagnosis of lung diseases and function.
Footnote: Although the above examples are all medical there are lots of industrial uses of using nuclear radiation from radioactive isotopes and many are described in sections 5a to 5d below.
Some general thoughts on the use of radioactive sources - radioisotopes
TOP OF PAGE
Reminders about the use of radioisotopes and radiation in medicine (medical physics)
A more detailed discussion is given near the top of the page - a quick reminder of why radioisotopes are so useful in diagnosing and treating medical conditions. Alpha emitting radioisotopes are usually too dangerous and not sufficiently penetrating to be of use in medicine. However despite the dangers, beta minus (electron emission), beta plus (positron emission) and gamma emitting radioisotopes are widely used in diagnostic medicine and treatments for dangerous medical conditions such as cancer.
5d Uses of positron radiation sources (beta plus decay nuclides) - PET scan use
One of the most important uses of beta plus (positron) emitters is PET Scanning in medicine.
Introduction to PET scans:
Why are PET scans are used?
How do PET scans work?
Atomic structure, radioactivity and nuclear physics revision notes index
RADIOACTIVITY multiple choice QUIZZES and WORKSHEETS
key phrases: IGCSE physics revision notes on uses of alpha, beta & gamma radiation KS4 physics Science notes on uses of alpha, beta & gamma radiation GCSE physics guide notes on uses of alpha, beta & gamma radiation for schools colleges academies science physics course tutors images pictures diagrams for uses of alpha, beta & gamma radiation science physics revision notes on uses of alpha, beta & gamma radiation for revising physics modules physics topics notes to help on understanding of uses of alpha, beta & gamma radiation university courses in technical science careers in physics jobs in the industry technical laboratory assistant apprenticeships technical internships in engineering physics USA US grade 8 grade 9 grade10 physics AQA physics science GCSE notes on uses of alpha, beta & gamma radiation Edexcel GCSE physics science notes on uses of alpha, beta & gamma radiation for OCR 21st century physics science OCR GCSE Gateway physics science notes on uses of alpha, beta & gamma radiation WJEC gcse science CCEA/CEA gcse science O level physics notes on uses of alpha, beta & gamma radiation GCSE chemistry IGCSE chemistry revision notes on uses of alpha, beta & gamma radiation KS4 GCSE Science revision notes on uses of alpha, beta & gamma radiation GCSE chemistry guide notes on uses of alpha, beta & gamma radiation for schools colleges academies science course tutors images pictures diagrams for uses of alpha, beta & gamma radiation science chemistry revision notes on uses of alpha, beta & gamma radiation for revising chemistry module topics notes to help on understanding of uses of alpha, beta & gamma radiation university courses in science careers in science jobs in the industry laboratory assistant apprenticeships technical internships USA US grade 8 grade 9 grade10 AQA chemistry science GCSE notes on uses of alpha, beta & gamma radiation Edexcel chemistry science notes on uses of alpha, beta & gamma radiation for OCR 21st century chemistry science notes on uses of alpha, beta & gamma radiation OCR GCSE Gateway science chemistry notes on uses of alpha, beta & gamma radiation WJEC gcse science chemistry notes on uses of alpha, beta & gamma radiation CCEA/CEA gcse chemistry notes science O level chemistry notes for uses of alpha, beta & gamma radiation IGCSE chemistry revision notes on uses of alpha, beta & gamma radiation O level chemistry notes what can we use radioisotopes for? what can we use alpha radiation for? what can we use beta radiation for? what can we use gamma radiation for? what are the medical uses of atomic radiation? why does radiation kill cells? why does nuclear radiation cause cancer? what is radiotherapy in cancer treatment? what is Technetium-99 used for? what is Cobalt-60 used for? what are the radioisotopes Iodine-123 Iodine-125 & Iodine-131 used for? How can you treat thyroid cancer with radiation? what are the radioisotopes Iridium-192 Potassium-42 Sodium-24 Xenon-133 & Krypton-81 used for? how do you use radioactivity in medical diagnosis? how are radioisotopes used in tissue and bone imaging? how are radioactive isotopes used to examine the lung and function? why is an alpha source used in smoke detectors? why are alpha emitters no good for tracer studies? how can beta radiation be used to monitor thickness? how a beta emitters used as tracers? how can gamma radiation be used to find leaks? how can gamma radiation find flaws in welding? why is food irradiated with gamma radiation? how does gamma radiation sterilise food? how does a PET scanner work? what are the medical uses of positron radiation? what is the medical diagnostic use of PET scans? what is positron radiation? what is the charge and mass of a positron? what is positron emission tomography used for? what are the uses of ionising radiation? describe some uses of nuclear radiation what are the uses and applications of atomic radiation - alpha radiation, beta radiation and gamma radiation techniques
Doc Brown's Chemistry
For latest updates see https://twitter.com/docbrownchem
Enter chemistry words e.g. topic, module, exam board, formula, compound, reaction, structure, concept, equation, 'phrase', homework question! anything of chemical interest!
TOP OF PAGE