by What are Alpha Emitters?
Alpha particles are a type of ionizing radiation made up of two protons and two neutrons, in other words a helium nucleus with a +2 charge. Some key things to know about alpha emitters include:
– Alpha particles have relatively low penetration power and cannot penetrate human skin. However, if an alpha emitter is ingested or inhaled, it can be dangerous as the radiation is emitted inside the body.
– Common alpha emitting radionuclides include uranium-238, uranium-234, plutonium-238, radium-226, and radon-222. Uranium and radium are considered some of the most hazardous alpha emitters to human health due to their long half-lives.
– Half-life determines how long it takes for half of the radioactive atoms in a sample to decay. Alpha emitters can have half-lives ranging from milliseconds to billions of years. Uranium-238 has a half-life of over 4.5 billion years, meaning it remains radioactive for an extremely long time.
Sources and Uses of Alpha Emitters
Major natural sources of Alpha Emitters include uranium and thorium ores found in the earth’s crust. Trace amounts of uranium and thorium are also present in all rock and soil. Some uses and occurrences of alpha emitters include:
– Uranium is used as fuel for nuclear power plants. It produces daughter products like radon during the process of radioactive decay.
– Radium was historically used in luminous paint for watches, instrument dials, and autres. This exposure led to health issues in workers known as “Radium Girls.”
– Thorium occurs naturally in monazite sands and is being investigated as a potential nuclear fuel. It decays into radium-228, which is an alpha emitter.
– Low levels of radon gas can accumulate in homes and buildings from uranium in the soil. Breathing radon is the second leading cause of lung cancer after cigarette smoking.
Health Effects of Alpha Particle Exposure
One of the main health risks from alpha emitters stems from their high energy and ionizing properties. Some key effects of internal alpha particle exposure include:
– Lung cancer: Inhaling or ingesting alpha emitters can lead to lung cancer due to radiation damage from alpha particles to lung tissue over time. This is why radon exposure poses a significant risk.
– Liver cancer: Ingested alpha emitters may accumulate and cause liver damage or cancer through repeated exposure to alpha radiation internally.
-Bone cancer: Certain alpha emitters like radium mimic calcium and deposit in the bones, irradiating bone tissue and raising risks of bone cancer or sarcoma.
– Genetic damage: High-LET (linear energy transfer) radiation from alpha particles can directly damage DNA and raise risks of genetic mutations passed down to offspring.
Protection from Alpha Particle Exposure
Due to their low penetration power, alpha particles pose little external risk but must not be inhaled or ingested. Some recommendations to reduce alpha emitter exposure include:
– Test homes for radon levels and install mitigation systems if levels are elevated above EPA action levels.
– Do not disturb uranium ore or mine tailings without proper protection from dust inhalation.
– Handle uranium or radium-based materials or antiques painted with radioluminescent paint using protective gloves to avoid ingestion or ingesting particles.
– Follow radiation safety procedures if working with alpha emitting materials in an occupational setting. Double barrier protection through ventilation and containment of the material keeps radiation exposures ALARA (as low as reasonably achievable).
Regulation of Alpha Emitters
Given the public health risks, many alpha emitting materials are tightly regulated for possession, transportation, use and disposal. Some key regulatory aspects include:
– The Nuclear Regulatory Commission licenses and oversees all commercial nuclear facilities, activities including uranium mining and milling, research reactors, and transport of radioactive materials including alpha emitters.
– OSHA regulates occupational exposure limits and procedures to control intakes of radionuclides including alpha emitters through internal and external dosimetry programs at NRC-licensed facilities.
– EPA regulates radon levels in buildings through the National Radon Program and works with states to promote testing and mitigation where radon levels exceed action levels of 4 pCi/L.
– The International Atomic Energy Agency provides standards and guidelines adopted by member states for safety in handling all radioactive materials.
While posing relatively low external hazard, alpha particles can be extremely destructive if inhaled or ingested due to their high energy and ability to directly damage tissue at the cellular level. Understanding sources and health implications of alpha emitters enables better protection of workers and the public. Ongoing research further improves mitigation and remediation methods for these hazardous radioactive substances.
Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
