Skip to content

Health impacts of indoor air

Good indoor air promotes good health, work efficiency and learning. An indoor environment that promotes health and well-being requires, in addition to high-quality indoor air, comfortable and functional premises that suit their purposes.

In Finland, the quality of indoor air is, on average, at a good level when compared to other European countries. However, the radon levels in indoor air is an exception to this: in certain areas in Finland, its concentrations may be higher than in many other countries.

Various contaminants or different circumstances can deteriorate indoor air quality. They can also be detrimental to the users of the premises or cause various symptoms. The concentrations of indoor air contaminants in regular working and office environments usually only cause mild symptoms that pass when the people leave the premises or when the building's defects are repaired.

Symptoms or circumstantial hazards related to indoor air may be caused by the following, for example:

  • incorrect temperature
  • draught
  • dry air in the room
  • insufficient ventilation
  • an excessive number of users in the premises
  • moisture and microbial damage
  • dust and fibres
  • poor cleaning
  • chemical emissions from building or interior decoration materials
  • cigarette smoke
  • various odours
  • allergens in the indoor air, such as pollen or animal dander
  • fine particles and other contaminants transmitted from outdoor air.

Symptoms connected to poor indoor air include:

  • irritation of eyes, the respiratory tract and skin
  • generalised symptoms, such as tiredness or headache
  • difficulties with concentration
  • respiratory tract symptoms (e.g. upper respiratory tract symptoms, cough or wheezing breath).

Inadequate ventilation or too dry or warm indoor air can cause generalised symptoms, such as headache and tiredness. The symptoms caused by poor indoor air can have a detrimental effect on working and learning abilities.

The symptoms are caused by many factors, and they are always dependent on the individual. Factors that affect the symptoms include, for example, the person’s immune defence, risk perceptions, general state of health, lifestyle and social aspects. Due to this, it is possible that only some of the premises’ users develop any symptoms. Some exhibit symptoms even if no contaminants have been discovered in the premises. The causes for these symptoms must always be reviewed by healthcare professionals, so that the person in question can be helped with recovery.

Many different factors can cause very similar symptoms, which is why symptoms alone cannot be used to deduce what is wrong with the building. The starting point for reviewing any indoor air problem must always be sufficiently extensive condition surveys. Many aspects that impact the quality of indoor air can be improved through maintenance and cleaning measures and by ensuring sufficient and functional ventilation.

Indoor air contaminants’ link to illnesses

A risk of an illness is linked to some indoor air contaminants if the exposure to them is extensive and long-term. Unrepaired and especially extensive moisture and microbial damage is are one of the risk factors of developing asthma. Moisture and microbial damage can also increase other respiratory tract symptoms. Any observed damage must be repaired and the causes reviewed, whether people using the building exhibit symptoms or not.

The most common causes related to indoor air causing health hazards and the risk of illness in Finland are

  • fine particles transmitted from outdoor air (risk factors of cardiovascular disease)
  • cigarette smoke (risk factor of cancer, among other illnesses)
  • radon (risk factor of lung cancer)
  • moisture damage (risk factor of asthma).

In addition to the contaminants listed above, asbestos released into indoor air is another risk factor of lung cancer. Increased risk of cancer is also related to PAH compounds in indoor air. The health effects of all these contaminants are related to the extent and duration of exposure, which means that minor or regular concentrations do not necessarily increase the risk in a notable way when compared to the other risk factors of various illnesses.

Tools for reviewing the indoor air quality and extent of symptoms

The City of Helsinki has the use of various tools and operational models to review the indoor air-related symptoms and experienced indoor air quality, assess the exposure conditions and evaluate the health-related impacts.

Condition and indoor air surveys: The experienced indoor air quality and the symptoms exhibited by users can be reviewed with various surveys. These include, among other materials, the condition questionnaire based on the Ministry of the Environment’s condition survey guidebook, the indoor air survey for pupils designed by the Finnish Institute for Health and Welfare, and the workplace indoor climate survey by the Finnish Institute of Occupational Health. However, a sufficiently extensive construction engineering investigation is the primary measure when resolving problem situations related to indoor air, as well as reviewing the potential contaminant sources.

Assessment of exposure conditions: An assessment of exposure conditions can be commissioned as a part of indoor air investigation work. It will be carried out by a building health expert. It is used to review whether the conditions of a building or a individual space therein deviate from the norm. The assessment considers the likelihood, quantity, quality and duration of the potential exposure to contaminants and unfavourable conditions. The classification of exposure condition applied to the assessment is 1) unlikely, 2) possible, 3) likely, and 4) highly likely.

Assessing the significance to health: Assessment of a building’s effects on health will be conducted by a doctor. The assessment is based on evaluating the exposure conditions, and it also considers the health of those using the building (such as their possible symptoms, illnesses and absences). It also considers other aspects related to using the premises (e.g., exposure time, working conditions and the special characteristics of work). There is no one, individual measurement or determination method to reliably assess a building’s impact on health.



19.08.2021 16:07