gas

Points out that increased thermal insulation and draughtproofing of homes can increase the risk to health of indoor air pollution. Includes condensation as a pollutant along with associated mould growth. Notes collaboration by Pilkington the glass company and the Timber Research and Development Association plus Laing the housebuilding group, to combat condensation by passive ventilation. Treats sources of indoor air pollution - formaldehyde, asbestos, gas appliances, tobacco smoke, thoron, radon.

Direct gas fired heated make-up air is used in industrial buildings to replace exhausted air and to achieve a comfortable temperature while avoiding draughts. This study presents the results of an investigation of the pollution from such a system under different conditions.

Air-to-air heat exchangers were evaluated as a method of maintaining indoor contaminant concentration levels below acceptable levels. A mathematical simulation of air infiltration and indoor contaminant generation was used todetermine the distribution of contaminant concentrations at various average intervals including hourly and yearly. Both spot generation such as from unvented combustion, and diffuse sources, such as from materials, were considered for four contaminants, nitrogen dioxide, carbon monoxide, carbon dioxide and formaldehyde.

Describes the influence of gas geisers on carbon monoxide and nitrogen dioxide production in 254 houses in the Netherlands. It was shown that burner type and maintenance system were the main factors influencing the carbon monoxide levels in the flue gases. The nitrogen dioxide concentration in the kitchen was greatly influenced by the presence of a flue for the geiser and by use of a cooker hood. Associations were also found with type of space heating, use of shower and socioeconomic status of the occupants.

Discusses sources of nitrogen dioxide in indoor air in houses in the Netherlands. Measurements were made in a random sample of about 300 houses with a geiser in Enschede and Arnhem. A second sample of 326 houses in Ede were measured a year later. The Dutch outdoor standard for concentrations of nitrogen dioxide was regularly exceeded indoors.

The influence of indoor nitrogen dioxide exposure on respiratory symptoms of school children was investigated in a case-control study. The election method used was useful in obtaining symptomatic children, but insufficient indefining cases and controls without additional information. No relationship between indoor NO2 and respiratory symptoms was found. Bias may have been present, especially because of the high mobility of the study population. Attempts to estimate historical exposure were inaccurate.

A small, personal monitoring study was performed in a subpopulation (14 families) of a case-control study on the relationship between indoor nitrogen dioxide exposure and respiratory diseases of school children. 

Indoor NO2 concentrations were measured in the kitchen, the living room and bedroom of 612 houses in two different areas in the Netherlands. In asub-sample, personal exposure of the housewives to NO2 was measured. NO2concentrations indoors depended on the presence or absence of (un)vented gas appliances. Personal NO2 exposure was only different between the two areas in the group with the lowest indoor concentrations. It was concluded that with respect to NO2 exposure it is impossible to categorize groups without accounting for gas appliances inside the house.

Most houses in the Netherlands are equipped with gas-fired heaters and cooking appliances, since large amounts of natural gas are available. Carbon monoxide poisonings occasionally occur due to the use of instantaneous water heaters (geisers) that are gas fired. An investigation was carried out to establish the carbon monoxide production potential of geisers under normal conditions of use. The study involved 254 houses: the results indicated that 17% of the geisers produced a carbon monoxide level of more than 50 microL/L in thekitchens where they were located, after 15 min of operation.

Summarizes the state of knowledge about combustion products, surface condensation and mould, formaldehyde and radon, and the guidance currently offered on their control in the UK. Statutory ventilation requirements are outlined and various measurement techniques described.