The functioning degree unit is utilized to measure combined alpha radiation from all radon decay items. Industrial test sets developed for use by the general public are widely available. The most common kinds consist of making use of charcoal canisters, alpha track detectors, liquid scintillation detectors, as well as ion chamber detectors. The examinations are usually designed to be returned to a qualified research laboratory for evaluation. The EPA estimates that virtually one out 15 houses in the USA has raised radon levels.