Alpha particle: An energized particle made up of two protons and two neutrons that is ejected from radioactive atom.1
Background radiation: The average radiation from all sources that is contained in outdoor air.1
Brick veneer: An ornamental layer of brick that is sometimes applied over cinder block walls.1
Bronchi: The two branches leading from the trachea to the lungs.1
Depressurization: A phenomenon that occurs when the air pressure outside of a building is higher than the pressure inside. Normally, buildings have higher pressure than outdoor air, but buildings may be depressurized when wood stoves, fireplaces, or furnaces draw indoor air for combustion. The slight vacuum that is created by depressurization can draw radon-laden air into a basement through cracks and openings.1
DNA: The storehouse of genetic information in cells.1
Dose: The amount of radiation that a person, or specific organ, is exposed to.1
Drain tile: A perforated pipe used to drain water away from the foundation of a house.1
Duct: A round, oval, or rectangular pipe-like passageway for moving air. A duct can be made of plastic, metal, wood, or fiberglass.1
Electrons: Negatively charged particles that orbit around the nucleus of an atom.1
Electrostatic precipitator: An air cleaner that removes dust particles from the air by electrically charging them so they'll be attracted to a plate with the opposite charge within the unit.1
Gamma rays: Short-wave electromagnetic radiation.1
Grade: The surface of the ground surrounding the house. Below grade means that part of the house is lower than the surface level of the soil.1
Half-life: The time it takes for a radioactive substance to decay. If the half-life of a substance is two years, half its radiation will be gone after two years.1
Heat exchanger: A device that transfers heat from one medium to another, such as an air-to-air heat exchanger used for heat-recovery ventilation.1
Hollow block walls: Walls made of concrete blocks that have hollow spaces in the middle. The spaces can be connected either horizontally or vertically.1
Ionizing radiation: Radiation capable of exerting enough energy to disrupt atoms by knocking electrons loose. This is the most dangerous type of radiation to human health.1
Micron: One-millionth of a meter.1
pCi/l: The abbreviation for picocuries per liter, which is the radon gas measurement unit.1
Permeability: The measure of a material's resistance to diffusion through it, in this case, diffusion of radon gas.1
Plate out: The tendency of radon daughter products to attach themselves to indoor surfaces such as furniture, walls, and the insides of heating ducts. Radioactive particles that plate out are essentially rendered harmless because they won't be inhaled.1
Radon: A naturally occurring radioactive gas that's colorless, odorless, and tasteless. It is formed by the decay of radium, which is itself a by-product of the radioactive disintegration of uranium. Radon gas has a half-life of 3.8 days.1
Radon daughter: One of the radioactive decay products of radon gas--polonium, bismuth, and lead.1
Remedial action: Work undertaken to lower radon levels in a building.1
Risk: The probability that something will happen, usually used to refer to something bad.1
Sill or sill plate: The horizontal wooden band that rests on top of a cinder block or poured foundation and extends around the entire perimeter of the house. The floor joists, which support the floor above, rest on the sill plate.1
Slab: a level layer of concrete, usually 3 to 6 inches thick, on which some houses are built. Slab-on-grade houses, as they are called, usually don't have any basement or crawl space.1
Soil gas: The gases that fill the pores between soil particles. Radon gas will be present in soil gases if the soil contains radium.1
Subatomic: Smaller than an atom. In other words, the parts of an atom: electrons, protons, and neutrons.1
Sump: A hole in the basement floor designed to collect water. The water may drain out by itself or be removed by a sump pump.1
Voids: The air spaces created within cinder block walls by the interconnecting of the holes in the middles of the blocks.1
Working level (WL): A measurement of radon decay products originally developed for uranium miners.1
Working level month (WLM): Exposure to one working level of radon for 170 hours.1
| Radon Publications |
1Radon, The Invisible Threat, What It Is, Where It Is, How to Keep Your House Safe, By: Michael Lafavore, Rodale Press, Emmaus, Pennsylvania, Copyright 1987.