A cross-sectional study was carried out to investigate the occurrence of the sick building syndrome (SBS) among office workers in Mauritius. A walk-through inspection and a questionnaire survey were carried out in 21 office building complexes to evaluate the prevalence of risk indicators for SBS symptoms among 302 office workers. Indoor climatic variables monitored were: carbon dioxide, carbon monoxide, nitrogen dioxide, air temperature, relative humidity, air movement, noise and light. All data collected were analysed using the EPl-info software.

The air, particularly the indoor air, contains a considerable burden of unwanted pollution. Overall there may be thousands of pollutants. They are brought in with the outside air or are generated from or within buildings. Most will be present in minute amounts but several will be present in measurable quantities. The reaction of people to the components of this pollution has little to do with toxicological assessment but is more concerned with political responses and media scares.

Much publicity has been given to the potential health risks posed by buildings, particularly those with mechanical ventilation or air conditioning. There have been concerns over the possible effects of the vocs given off by the furnishings and finishes, of fungal spores shed from dirty ducting, of legionella distributed by wet cooling towers, of insufficient ventilation air, etc., etc. The list of concerns is a long one. But what about the effects on the building occupants of the air brought in from outside, the so-called 'fresh air'?

The CIBSE is to publish new guidance on environmental criteria later this year. This includes new material on Indoor Air Quality which provides a strategy for minimising indoor air quality problems in buildings and improving the effectiveness of outdoor air supply in controlling indoor pollution. This Chapter explains the reasons for this approach and the basis for the guidance given.