Reports measurements of suspended particulate matter, carbon monoxide and droplet nuclei in a climate chamber of 50m3 as indicators of the particulate and gaseous phase of cigarette smoke. Various combinations of smoking intensities andventilation rates between 1 and 16 air changes per hour were investigated partly by a standardized smoking machine procedure and by individual smoking by a panel of four persons.

Reports first report from committee, "Preliminary proposals for measures against radiation risks in dwellings". Notes that prime source of radiation, alum-based lightweight concrete, has been banned in new buildings in Sweden, but is still present in 10%of pre-1975 houses. Provisional limits for gamma radiation for undeveloped sites: 30-100 micro.r/h (site should only be built on subject to other conditions), more than 100 micro.r/h (building inadvisable). suggests that geological radiation maps be charted. Notes reduction in radon content through house ventilation.

Investigation has shown connection between radon content in mines and lung cancer in miners. Radon is also present in building structures. Presents measurements carried out inNorwegian houses and discusses consequences of radiation doses absorbed in human lungs as well as biological effects of background radiation. Diagram illustrates concentration of radon in concrete, brick and wood. Analyses factors which affect radon content, particularly barometric pressure and ventilation rates.

Notes that indoor air can contain between 01 - 100 x 10\9 ppm particles and that sub-micronic particles (1 -100 micro m) dominate. Defines indoor as microbiological laboratories, public buildings including the stations, nurseries, cinemas etc. and dwellings. Lists sources of pollution and tabulates limit values for aerosols noting those which are carcinogenic, absorbed through the skin, allergy-producing. Maximum limits stated are for 15 min/hour exposure rate. Discusses risks involved and how injury can be prevented.

Outlines causes of air infiltration. Discusses the air leakage paths of openings and measures that can be taken to reduce air leakage. Concludes that air infiltration should never be relied upon for ventilation but efforts should be made to make the building envelope more airtight, and a mechanical ventilation system should be installed.

Gives preliminary report of a study of natural ventilation and energy consumption in low-cost housing. The study includes the measurement of infiltration rates using tracer gas, pressure differences across outside walls, indoor and outdoor temperatures, air tightness of external walls and the position of windows and doors. Outlines future studies and gives preliminary conclusion that making houses more air tight can save energy.

Reports measurements of the wake flows behind solid and porous fences, made with a pulsed wire anemometer (PWA) and a hot-wire anemometer (HWA). Discusses results which show the superiority of PWA in correctly measuring the highly turbulent and sometimes re-circulating wake flows. Gives empirical formula for profile of the velocity defect and shear stress perturbations. Concludes that porosity, and not the form of construction of thefence, determines the structure of the wake flow. States that in general it is difficult to say which value of porosity provides the best shelter.

Gives regulations and performance guidelines for the ventilation of buildings. Includes guidelines for air quality and gives recommended supply and return air volumes for different rooms of a building.

Notes dangers of incomplete theoretical models distorting technical progress. Cites as example determination of U-value in estimating energy losses through building envelope. Concentrates on considerable energy loss caused by air infiltration, in addition to heat transmission. A step towards a better understanding of total energy flow through building envelope is a method of calculating air leakage. Describes calculation results for a house which show that air tightness is an important property of the building envelope which cannot be neglected.