radon daughter

Reports measurements of radon daughters in air. The daughters were collected on filters for different lengths of time. A silicon semiconductor detector and the etch foil technique were used to measure the alpha particles from the radon daughters. Finds that alpha particle concentrations in living rooms have the same variation with time as outdoors.

Reports tests of the effect of various air treatment devices on the radon daughter concentrations within a room. Test were carried out using an electrostatic precipitator, a humidifier and a dehumidifier. The ventilation rate of the room was measured using Krypton 85 as a tracer gas.< Finds that the use of a humidifier, dehumidifier or carbon filter gave no significant alteration to the radon concentrations in the room, but that the electrostatic precipitator reduced the concentration considerably and was equally effective when operated with or without the carbon filter.

Reports investigation into the radon dose from inhaled radon daughters during exposure indoors. The initial phase of the investigation comprised detailed measurements of radon daughter concentrations in each of four locations in the New York area. The investigation has now broadened considerably. Time-integrated measurements of radon concentrations and working levels have been obtained in twenty dwellings in New York and New Jersey in a two year period with which to estimate annual mean exposures of the inhabitants.

Describes a method of measuring airborne concentrations of radon daughters which distinguishes between the different isotopes. At the place of sampling, air is flowed through a millipore filter for five to ten minutes at approximately 12 litres per minute. The filter is counted during the period 2 to 12 minutes post sampling; the counts are integrated over each of four regions of energy and a second count made for the same regions during the period 15 to 30 minutes post sampling. Results are analysed by a BASIC computer program.

Briefly describes instrumentation and techniques for measuring concentrations of radon daughters in air. Reports measurements of radon daughter levels made in nine structures in Grand Junction, Colorado. Tailings from uranium mines had been used in their construction and measurements were made in the basement or first-floor of slab type structures. Gives results in the form of average concentration with standard deviation.

Presents a new concept of describing the tolerance level of radon daughters. This concept is in terms of the alpha-energy dose resulting from the complete decay of the daughters. Describes a rapid field method for determining atmospheric concentrations of radon daughters in terms of Mev of alpha energy/liter. No attempt has been made to set a maximum allowable concentration for radon and/or its daughters. Should an M.A.C.