radon

The largest contribution to population exposure from natural radiation arises from the inhalation of the decay products of radon in indoor air. In most instances the dominant source of radon within buildings is the subjacent ground. However, building materials do contribute to the radon concentration in indoor air, and in some circumstances may provide the major source. Thisreport reviews some of the literature on radon emanation from soils and building materials world-wide.

Reducing the air change rate of a house increases the concentration of pollutants in the indoor air. These pollutants are identified and located within the residential structure. Air-to-air heat exchangers are suggested tocontrol ventilation, and the three basic types described.

Indoor air quality sampling strategies and analytical techniques have changed significantly in the past ten years. The changes reflect both the shifts in study objectives and the development of new forms of instrumentation. Toillustrate these trends, this paper describes early field techniques for measuring indoor air quality using a heavily instrumented mobile laboratory that is suitable for measuring one building intensively for up to four weeks.The style of measurement now is complemented by large field survey projects using passive samplers as the dominant instrumentation.

A pilot study was conducted using workers from a semiconductor plant. Describes the methods used to acquire and evaluate air pollution exposure data for significant environments (including workplace, in-transit, and residence) to which workers are exposed throughout a typical 24-hour day. Summer andwinter measurements were made on products of combustion, radon, respirable particulates, and a variety of organic compounds including methylene chloride.

The Harvard School of Public Health and the Energy and Environmental Policy Centre of the Kennedy School of Government, under the auspices of the Electric Power Research Institute and the Gas Research Institute, conducted a"Workshop on Evalu

Eleven countries are cooperating to establish guidelines for minimum ventilation rates which are sufficiently large to meet the demand for outdoor air in buildings without unnecessarily wasting energy. The most important pollutants have been identified as: carbon dioxide, tobacco smoke, formaldehyde, radon, moisture, body odour, organic vapours and gases, combustion products and particulates. To a certain degree some of thesesubstances can be used as indicators for acceptable air quality to establish minimum ventilation rates.

The relation between air infiltration rate and indoor concentrations of radon gas, radon daughters, and formaldehyde has been investigated for both summer and winter conditions in a number of Toronto houses with low rates of natural ventilation.

Describes the work of the Department of Climate and Building Services of the National Swedish Institute for Building Research. Full scale trials, field measurement and measurement technology and methods applied to indoor climate are described. Research on airtight buildings, radon, air quality and efficient ventilation, occupant requirements and effects on human performance is also summarised. Dummies are used to measure heat transport to or from parts of the body, and for measurement of humidity.

Describes expectations people have of indoor climate. Notes that the quality of indoor climate has often taken second place to fashionable architectural and material considerations. Refers to concern for improved environment and awareness of formaldehyde, radon and other pollutants and the need for correct ventilation to achieve derived air quality. Provides guidelines for air quality, and the thermal environment in both housing and working premises.

Radon concentrations were measured in about 1000 Dutch dwellings and at 200 outside locations using passive monitors. A median concentration of 24 Bq/m3 was found for the dwellings with a highest value of 190 Bq/m3. Seasonal effects were found to be small. Correlations were observed between median radon concentrations and construction parameters including ventilation rate. The concentrations outside show an unexpected dependence on the location. Comparison with previous grab-sampling data on radon-daughter concentrations reveals an average equilibrium factor of 0.3.