radon

This paper examines the frequency distribution of indoor radon concentrations and air exchange rates in conventional and energy-efficient houses, discusses radon source magnitudes, compares the distribution of source magnitudes with information on emanation rates from source materials, and, finally, considers the ways in which variability in source magnitude might affect regulatory efforts to control indoor concentrations of radon and its daughters.

This paper reviews the literature on sources and measurement of natural airborne radionuclides and radiation in buildings. It also briefly reviews control measures and suggests areas for further research. The major emphasis is given to radon 222 and its daughters, since they typically cause thelargest organ dose to the general population, most of which arises from indoor exposures. The indoor radiation field from radionuclides fixed in building materials and soil is also given substantial treatment.

Sixty houses built with widely different construction practices and located in different areas in upstate New York were monitored for airtightness (using fan pressurization) and integrated radon concentrations in indoor air, household water,

A passive integrating radon gas dosemeter has been developed using electrochemically etched tracks in CR-39. The detectors were used in a survey of 2000 homes in the UK. The response of the dosemeters is shown to be linear with respect to exposure. It is shown that snap-on polyethylene lids allow 222Rn to diffuse into the detector cup while excluding radon daughters, dustand 220Rn. Initial results from a trial survey are presented.

A representative sample of over 2,000 UK dwellings was monitored for a year using thermoluminescent and etchable plastic dosemeters to measure gamma ray dose rates and radon concentrations. 

Models have been developed to enable prediction to be made of the dose incurred indoors from gamma radiation and from inhalation of radon decay products. 

Twelve energy-efficient houses in Eugene, Oregon, USA, were measured for effective leakage area using blower door fan pressurization. Air exchange rates over a period of several hours were determined by tracer gas decay analysis. 

In the past several years measurements of radon and its daughters made in residential buildings in the USA indicate that in some situations the potential health hazard to the occupants of buildings from inhalation exposure can be significant.

The effects of retrofitting for building tightness, air-to-air heat exchangers, and HVAC circulation fans on radon and radon progeny levels were investigated using two matched test houses.

There are three general categories of techniques for the control of radon and radon progeny concentrations in indoor air - restriction of radon entry, reduction of indoor radon concentrations by ventilation or air cleaning, and removal of airborne radon progeny.