Reply #95: Here's an EPA article that addresses Alpha Particles... [View All]

[Junkdrawer]

http://www.epa.gov/radiation/understand/alpha.htm

How do alpha emitters get into the environment?
Most alpha emitters occur naturally in the environment. For example, alpha particles are given off by uranium-238, radium-226, and other members of the uranium decay series. These are present in varying amounts in nearly all rocks, soils, and water. However, human activity, create or worsen the potential for exposure of people and contamination of various environmental media. For example, uranium mining wastes, known as uranium mill tailings, have high concentrations of uranium and radium. Once brought to the surface, they can be become airborne or enter surface water as runoff. A second example is the mining and processing of phosphate for fertilizer. The currently used process generates large piles or "stacks" of phosphogypsum, in which naturally occurring radium is concentrated.

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How can alpha particles affect peoples health?
The health effects of alpha particles depend heavily upon how exposure takes place. External exposure (external to the body) is of far less concern than internal exposure, because alpha particles lack the energy to penetrate the outer dead layer of skin.

However, if alpha emitters have been inhaled, ingested (swallowed) or absorbed into the blood stream, sensitive living tissue can be exposed to alpha radiation. The resulting biological damage increases the risk of cancer; in particular, alpha radiation is known to cause lung cancer in humans when alpha emitters are inhaled.

The greatest exposures to alpha radiation for average citizens comes from the inhalation of radon and its decay products, several of which also emit potent alpha radiation.