MEDICAL - Production

Production:
An outline on how Strontium-90 is created.

Strontium was first detected as non-reactive in the mineral strontianite in Scotland. Radioactive Strontium-90 (Sr-90) was discovered in the 1940’s in a nuclear experiment linked to the atomic bomb. Large amounts were produced during atmospheric nuclear weapons test in the 1950’s and 60’s and was dispersed worldwide. Sr-90 is produced as a by-product of the fission of Uranium in nuclear reactors and in nuclear weapons.

²³⁵₉₂ U ---(fission)---> ⁹⁰₃₆ --> ⁰_-1 e^- + ⁹⁰₃₇ Rb --> ⁰_-1 e^-  + ⁹⁰₃₈ Sr 

MEDICAL - Radiation

Radiation:

As isotopes decay they emit radiation. 

The radiation is detected by a liquid scintillation counter

Sr-90 emits beta particles only to decay into Yttrium-90 shown in the decay equation below:

⁹⁰₃₈Sr --> ⁰ _-1e^-+ ⁹⁰₃₉Y

Yttrium will decay also by beta emission to achieve nuclear stability as Zr-90:

⁹⁰₃₉ Y --> ⁰_-1e^- + ⁹⁰₄₀ Zr

MEDICAL - Uses & Properties

Properties and Uses: 

Properties of Strontium-90 will impact the way in which it is used.

Below lists the relationship between Sr-90 Properties and Uses:

Properties:	Uses:
Soft metal like, fresh and lustrous. Turns yellow quickly in air. It is in the form of a soft metal and can be in dust form also.	This is very reactive in air, when freshly cut it will react with the air and burst into flame.
Radioactive Strontium-90 only emits Beta particles, no gamma. As it decays it generates heat.	This heat can be converted into electricity. This can then be used in long-lasting batteries and portable power supply. This includes space vehicles, navigational beacons and weather stations in remote areas. Also used in Russia as radioisotope thermoelectric generators.
Strontium has a half-life of 29 years.
Strontium has non-radioactive isotopes and also radioactive isotopes such as Sr-90	Radioactive source in the process of thickness gauging. Useful for treatment for certain cancers. These radiation properties are useful in radiation therapy in the medical field (treating cancer by controlling ‘malignant’ cells). This treatment is a controlled amount of Sr-90 for bone cancer. Radioactive tracer measuring rates of chemical reactions.

Strontium-90 as a Cancer Treatment: 

Strontium is also used in radiation therapy for bone cancers that are unresectable. It uses high energy rays to kill the cells and a high dosage is needed. However through this radiation, it can also kill healthy nerves and cells that surround. Surgery is used to remove cancer along with the radiation. The radiation can also be used if the cancer comes back to relieve pain and swelling.   

MEDICAL - Safety

Safety: 

Safety including benefits and problems from Strontium-90.

Benefits and Problems:

Benefits	problems
Sr-90 can be used industrially in portable batteries for space vehicles and isolated weather stations. It is a long-life power source as its half life is 29 years.	Exposure to Sr-90 can lead to health hazards such as cancer to the bone and leukemia. This risk depends on the amount of concentration in the environment. Since nuclear bomb testing and Chernobyl disaster, everyone is exposed to some Sr-90.
Sr-90 is a relatively abundant isotope and under controlled concentrations can treat certain cancers.	As Sr-90 is radioactive and decays by beta emissions, Y-90 will also be present. This could have risks to burning the eyes and skin from external exposure.

Further Safety:

Precautions: 

• The radioactive material can only be removed by a trained person
• When treating a patient the applicator must be moved fast but careful, not looking at it with the naked eye
• The surface of the applicator must not touch the fingers
• Must be thoroughly cleaned and stored in its shielded box 

Storage:
As Sr-90 is a very reactive isotope with the air, it is stored in Kerosene or mineral oil. 

Disposal:

As this is a highly radioactive isotope it will be disposed of in a "spent fuel pool" made of thick concrete lined with steel. Once these are full they are put into "dry cask" storage made of stainless steel and concrete.

MEDICAL - Discussion

Discussion: 

Through a series of sources with a reputable name, information was sourced and used to construct a website. The information on this website is considered to be reliable through reading repeated information from various sites. this an example of the consistency shown in the sources used as information overlapped and matched. These websites make themselves valid through an author or organisations name and a date of publish. This information has been made valid and reliable as a secondary source. However there was contradictory equations and production methods of Sr-90.

Reference List: 

(US.EPA, 2012) Accessed: 16/05/15 (http://www.epa.gov/radiation/radionuclides/strontium.html#properties) 

(OPHPR, 2014) Accessed: 16/05/15(http://www.bt.cdc.gov/radiation/isotopes/strontium.asp)

(Department of Health and Human Services, 2005) Accessed: 17/05/18(http://www.bt.cdc.gov/radiation/isotopes/pdf/strontium.pdf)

(American Cancer Society, 2015) Accessed: 18/05/15 (http://www.cancer.org/cancer/bonecancer/detailedguide/bone-cancer-treating-radiation) 

(Director-General of Health, 2010) Accessed: 18/09/15

(http://www.nrl.moh.govt.nz/regulatory/c13.pdf )