radon

Discusses the public's knowledge of indoor air quality and their sources of information, including word of mouth and the media.

Looks at some studies that have been done to see if the retrofits have actually changed indoor air quality and changed pollutant concentrations. The first study (1981) of 18 homes in Washington state used the house doctor technique. The second study was of two homes in Medford, Oregon and one in Cranbury, New Jersey, all monitored for two weeks. The third study was of two identical houses in Rockville, Maryland, monitored over a year. One of them was retrofitted using the house doctor technique, as a result of which air leakage dropped by 40%. A fourth study of fifty houses is mentioned.

Discusses the need for and current state of standards for indoor air quality, and the various organisations responsible for setting them in the USA. Particular reference to ASHRAE standard 62-1981 and 62-1974.

Discusses the physical, chemical and biological effects that moisture can have on indoor air pollutants such as formaldehyde, radon, aerosol particles, minerals from concrete, ozone, nitrogen dioxide, polyurethane, microbes and organic vapours.

Discusses building 'safe' houses, describes the decay chain of uranium 238 and the qualities of radon, and risks of developing lung cancer run by miners and householders. Figures for lung cancer in the USA are quoted. Details from three studies in Houston, Maine and Sweden are given. Discusses sources of radon, e.g. water, building materials, soil. A study of houses in Pennsylvania indicated that high radon concentrations occurred over Cambro-ordovician sediment rock. Discusses movement of radon from soil into dwellings.

Introductory talk on the indoor air quality problem. Compares risk of radon pollution in houses to the risks of smoking tobacco, and gives a definition of levels of concern. Mentions filtering of indoor air by means of an air-to-air heat exchanger, the interaction between ventilation and sources, e.g. unvented combustion heaters and carbon dioxide emissions; measurements of nitrogen dioxide are compared, and formaldehyde concentrations in 28 different commercial buildings.

Uses a model to estimate the incremental risk of lung cancer associated with increased radon concentrations in indoor air resulting from decreased air infiltration caused by increased air tightness of dwellings. Gives results for selected changes in the air exchange rate. Discusses findings.