A healthy indoor environment

The indoor environment and its effects on health

There are a number of factors in the indoor environment that can affect health. Over the years, considerable work has been undertaken to gradually limit the environmental factors that have negative effects on our health. At the same time, the nature and extent of the environmental factors affecting us are continually changing. The impact on the environment of motor vehicles, industrial emissions and emissions from building heating systems can be mentioned as examples. The intake into buildings of polluted air from outdoors is not uncommon. Since we stay indoors for around 90 per cent of our lifetimes, the content of the air we breathe indoors must be considered important. Inside buildings, air is polluted by emissions from building materials and other substances, and by the people in the buildings. Well-functioning ventilation systems that are adapted to the activities taking place in buildings are a fundamental prerequisite for achieving good indoor air.

However, our knowledge of the relation between the indoor environment and illness is incomplete. It is probably always a question of processes in which a number of factors play a role, which makes it extremely difficult to draw conclusions on single factors. Studies show, however, that allergies and other types of hypersensitivity are on the increase. Among the factors significantly affecting people's health can be mentioned radon contamination, tobacco smoke, formaldehyde, house dust mites and so-called "damp buildings" which are, in fact, often badly ventilated buildings.

Improved ventilation system

A well-functioning ventilation system can be one means of mitigating the above-named factors. In 1992, compulsory inspections of ventilation systems were introduced in Sweden in the light of suspicions that ventilation systems were not previously being checked and maintained.

With respect to the environmental quality objective a Good built environment, the former Swedish Government and Riksdag have decided on an interim target for the indoor environment that means that buildings and their properties should not have negative effects on health. This interim target focuses on conditions in housing, schools and pre-schools regarding functioning ventilation systems and effective means of preventing radon contamination.