pollutant

Notes the considerable savings in heating energy that could be made if ventilation rates could be modulated so that only the requirements of the actual number of occupants was supplied. Explains how this can be done by ventilating to maintain a constant concentration of carbon dioxide. Describes carbon dioxide monitoring system based on infrared absorptiometry. Illustrates diagrammatically the layout of a cinema ventilation system which monitors carbon dioxide levels and explains its operation. Notes other buildings where the system is used.

Due to better insulation and improved airtightness of doors and windows, the supply of fresh air entering a room has been greatly reduced. This in turn causes an increase in the amount of pollutants emitted by different insulation and building materials. Measurements of the formaldehyde concentration in newbuildings have shown that the admissible limits are still exceeded even after a year. Stricter regulations limiting the emissions of pollutants are therefore urgently necessary.

Measurements of radon and radon daughters in 11 buildings in five states, using active or passive solar heating showed no significant increase in concentration over the levels measured in buildings with conventional heating systems. Radon levels in two buildings using rock storage in their active solar systems exceeded the U.S. Nuclear Regulatory Commission's 10 CFR 20 limit of 3 pCi/l for continuous exposure. In the remainder of the buildings, radon concentrations were found to be at levels considered to be normal.

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.

Three different investigations of radon in Swedish dwellings are presented - a nationwide study conducted primarily to determine the collective dose to the Swedish population from exposure to radon and radon daughter, a supplementary study of newly built detached houses in order to find out whether theregulations in the Building Code prescribes acceptable radon levels in new houses built on normal ground, and measurements made by the local authorities in order to find houses with levels of radon daughters above the norm.

To develop effective monitoring and control programs for indoor radon it is important to understand the causes of the broad range of concentrations that have been observed. Measurements of indoor radon concentration and air-exchange rate in dwellings in several countries indicate that this variability arises largely from differences among structures in the rate of radon entry.

Volatile organic chemicals in indoor air of a home-for-the-elderly and a new local government office building were identified and quantified using Texax GCR samplers and capillary gas chromatography/mass spectrometry analysis. Over three hundred chemicals were tentatively identified in indoor air of thehome-for-the-elderly. Comparison of night-day levels were made. The new office building was also part of a longitudinal study which revealed a rapid decrease in levels with time for some chemicals (after completion) while others increased.

Examines the effects of smoking rate, ventilation, surface deposition, and air cleaning on the indoor concentrations of respirable particulate matter and carbon monoxide generated by cigarette smoke. A general mass balance model is presented which has been extended to include the concept of ventilation efficiency. Following a review of the source and removal terms associated with respirable particulates and carbon monoxide, we compare model predictions to various health guidelines.

The problem of indoor air pollution has many facets, ranging from excess humidity, mould and insects over emissions from gas boilers to high levels of various chemicals in tight buildings. The common denominator of all these problems is the existence of several sources of pollution inside a volume of relatively low dissipative capacity. Where the resulting concentration from a single substance exceeds an already established hygienic standard regulatory measures are straightforward. Assessing the risk of several substances being present at the same time is still difficult.

The problem of radon emission in buildings first came to light at the end of the 1970s, when a report by the Swedish National Institute of Radiation Protection revealed high radon daughter concentrations in some houses. Temporary limits on permitted concentrations in different types of dwellings were imposed in Sweden. They were related to the age of dwellings, due to the known historical use of alum shale in lightweight concrete.