Radioactive Isotopes

Monday, July 26, 2010

Personal protective equipment (PPE)


All the laboratory users handling hazardous materials especially radioactive isotope must wear the appropriate Personal Protective Equipment (PPE). According to standard laboratory PPE, it includes a laboratory coat, safety glasses and gloves.

There are two most common routes of exposure when handling chemicals in the laboratory which is inhalation and skin contact or known also as absorption. Inhalation hazard can be reduced by handling chemicals in the fume hood and thus can provides protection from splashes.



Gloves

Gloves are used to protect hands and in some cases portions of the arms from in contact with a hazard.






Lab Coats


The used of laboratory coat is important when entered the laboratory especially involve direct use of hazardous materials like radioactive isotope. Here is the tips on what to do if laboratory coat becomes contaminated with radiactivity:

Place the lab coat in a plastic bag, seal, label and hold for laundry. Make sure the laundry of lab coat do not mix with other clothes in order to prevent any contamination.




Eye protectio
n

As a minimum standard, safety glasses must be worn while handling radioactive isotope and other hazardous materials. There are three types of eye protection:

i. Safety glasses

Approved safety glasses are those which meet the American National Standards Institute (ANSI) Z87 testing criteria. Approved glasses are marked by referred to its number Z87 on the inside of the temple. However, do not remove side shields from these glasses. Safety glasses offer good impact protection but it very limited to splash protection.



ii. Goggles


The eyes and face should be protected from potential splashes by conducting work with hazardous substances in a chemical fume hood. When chemical fume hood is not in used, a chemical splash goggles underneath a face shield must be worn and there might have a potential for a hazardous substance to splash especially radioactivity materials.
Thus, goggles is one of the personal protective equipment that must be take into consideration.


iii. Contacts

If laboratory users choose to wear contacts when handling radioactive materials, ensure to wear safety glasses. In the event of a chemical splash to the eyes, contacts can hold the chemical against the eye which prolonging the exposure and increasing eye damage.


Respiratory Protection

Lab ventilation and chemical fume hoods are typically control exposure to hazardous chemicals. There will be medically clear, fit test, train and issue a cartridge respirator to a laboratory users if there is a potential for over exposure. This will be done by a certificated person.







Foot protection


Laboratory users must wear sturdy-soled, well fitting shoes that cover the entire foot. Those sandals, slip-ons, perforated shoes like Crocstm and open shoes are not allowed while entering the laboratory. leather shoes are recommended like safety boots.







1 comment:

Types of radioactive isotopes by origin


1) Long-lived radioactive nuclides

Some radioactive nuclides that have very long half lives were created during the formation of the solar system (~4.6 billion years ago) and are still present in the earth. These include 40K (t½ = 1.28 billion years), 87Rb (t½ = 48.8 billion years), 238U (t½ = 447 billion years), and 186Os (t½ = 2 x 106 billion years, or 2 million billion years).

2) Cosmogenic

Cosmogenic isotopes are a result of cosmic ray activity in the atmosphere. Cosmic rays are atomic particles that are ejected from stars at a rate of speed sufficient to shatter other atoms when they collide. This process of transformation is called spallation. Some of the resulting fragments produced are unstable atoms having a different atomic structure (and atomic number), and so are isotopes of another element. The resulting atoms are considered to have cosmogenic radioactivity. Cosmogenic isotopes are also produced at the surface of the earth by direct cosmic ray irradiation of atoms in solid geologic materials.

Examples of cosmogenic nuclides include 14C, 36Cl, 3H, 32Si, and 10Be. Cosmogenic nuclides, since they are produced in the atmosphere or on the surface of the earth and have relatively short half-lives (10 to 30,000 years), are often used for age dating of waters.

3) Anthropogenic

Anthropogenic isotopes result from human activities, such as the processing of nuclear fuels, reactor accidents, and nuclear weapons testing. Such testing in the 1950s and 1960s greatly increased the amounts of tritium (3H) and 14C in the atmosphere; tracking these isotopes in the deep ocean, for instance, allows oceanographers to study ocean flow, currents, and rates of sedimentation. Likewise, in hydrology it allows for the tracking of recent groundwater recharge and flow rates in the vadose zone. Examples of hydrologically useful anthropogenic isotopes include many of the cosmogenic isotopes mentioned above: 3H, 14C, 36Cl, and 85Kr.

4) Radiogenic

Radiogenic isotopes are typically stable daughter isotopes produced from radioactive decay. In the geosciences, radiogenic isotopes help to determine the nature and timing of geological events and processes. Isotopic systems useful in this research are primarily K-Ar, Rb-Sr, Re-Os, Sm-Nd, U-Th-Pb, and the noble gases (4H, 3H-3He, 40Ar).

Because of their stable evolution in groundwater, such naturally occurring isotopes are useful hydrologic tracers, allowing evaluation of large geographic areas to determine flowpaths and flow rates. Consequently, they are helpful in building models that predict fracturing, aquifer thickness, and other subterranean features.


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