English

Discusses the future prospects of domestic ventilation and whether mechanical ventilation will be necessary to satisfy requirements as windows become more airtight. Suggests use of centralized mechanical ventilation, with openable windows for summer ventilation.

The filtering effects of three types of air control systems at two wastewater treatment plants on viable particles were investigated. Aspergillus fumigatus and other thermophilic organisms were used as monitors for viable particles. The indoor concentrations of viable particles were found to be affected by building design and the use of conventional mechanical air systems. Viable particles of approximately 4.0 microm and greater in aerodynamic diameter were filtered from the air while respirable size particles less than 4.0 micromwere not filtered as well.

This paper reviews the literature on sources and levels of pollutants in buildings and looks at the possible effects of a reduction in ventilation rates on the health and comfort of building occupants.

Large, multicelled and naturally ventilated buildings pose many inherent problems for the measurement of overall infiltration rates using tracer gases. Considering a single tracer gas decay technique, the most obvious problems are: (a) local variations in infiltration, (b) imperfect internal mixing of the air, and (c) practical difficulties in distributing (ie, seeding) the tracer gas and subsequently obtaining air samples.

Examines four pollutants found in significant amounts in biomass smoke: respirable particulates, carbon monoxide, formaldehyde and particulate benzo(a)pyrene, to effect a comparison between tobacco smoke and biomass fuel smoke. Nominal doses of formaldehyde and carbon monoxide are roughly similar. For respirable particulates, smokers receive more than a factor of 10 larger nominal doses. The reverse is true for benzo(a)pyrene.

A passive integrating radon gas dosemeter has been developed using electrochemically etched tracks in CR-39. The detectors were used in a survey of 2000 homes in the UK. The response of the dosemeters is shown to be linear with respect to exposure. It is shown that snap-on polyethylene lids allow 222Rn to diffuse into the detector cup while excluding radon daughters, dustand 220Rn. Initial results from a trial survey are presented.

A representative sample of over 2,000 UK dwellings was monitored for a year using thermoluminescent and etchable plastic dosemeters to measure gamma ray dose rates and radon concentrations. 

Models have been developed to enable prediction to be made of the dose incurred indoors from gamma radiation and from inhalation of radon decay products. 

The National Radiological Protection Board has undertaken a large scale environmental survey of radiation levels in homes throughout the United Kingdom. Passive radon and gamma ray dosemeters were posted to a representative sample of households. Lithium fluoride thermoluminescence dosemeters were used to assess natural gamma radiation and were left in the measurement location for a period of six months before being returned to the Board for processing. As a preliminary to the national survey, several limited surveys were undertaken in regions of igneous and sedimentary geology.

Discusses the sources and concentrations of organic compounds in indoor environments. Describes work done by the Lawrence Berkeley Laboratory in the USA on formaldehyde and poor air quality in offices.