The working degree unit is utilized to measure combined alpha radiation from all radon decay items. Industrial test sets made for usage by the general public are widely offered. One of the most typical types consist of the use of charcoal cylinders, 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 approximates that almost one out 15 houses in the USA has elevated radon levels.