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Information and frequently asked questions

Who can give me information?

The supervisor of the site serves as the contact person between the users of the City’s facilities and the maintenance personnel. If you need information about the condition of a school or daycare centre, for example, you should first talk to the principal or director of the daycare centre.

The Urban Environment Division is responsible for ordering indoor air investigations and repairs in service facilities owned by the City. To ensure that any questions and information requests related to the condition, investigations, and repairs to buildings are delivered to the intended recipient as quickly as possible, they should be sent using the feedback form.

The City’s Environmental services are the health protection authority in charge of monitoring to ensure that public facilities cause no health hazards. Environmental services can also instruct you in matters related to indoor air or moisture problems in apartments.

Customer announcements

About 300 user announcements regarding the condition, investigations, and repairs to the City’s facilities are issued to the users of the facilities every year. Information and customer announcements related to the indoor air in the City’s buildings are mainly produced by the Urban Environment Division. The announcements published after 1 January 2017 are available through the Talotiedot service.

Browse the announcements »

Survey reports

The condition survey reports are public and are published through the Talotiedot service. If you cannot find the report you are looking for on the website, you can request it with a feedback form or from the persons giving more information, as named on the customer announcements. For questions related to the survey, you can contact the indoor air expert named on the announcement.

Frequently asked questions

 1. How long do the investigations take?

 The planning process of an indoor air investigation has many stages and involves many operators. The investigation phase usually lasts 4–6 months. During the investigation phase, time is spent on such processes as reviewing building drawings and potential previous investigations, field studies, analysing laboratory samples, and writing and reviewing the report. Observations may emerge during the investigation that require a wider scope of investigation.

2. Who will carry out the indoor air investigations?

The City will order the condition surveys from external research consultants selected through a tendering process. Strict quality criteria are in place for the researchers and research methods. The consultants are selected based on price and quality for two years at a time, with an option for one or two additional years.

3. How does poor indoor air affect health?

Several factors in a building can bring down its comfort level and cause various symptoms. Inadequate ventilation or too dry or warm indoor air can cause generalised symptoms, such as headache and tiredness. The dustiness of premises can also cause symptoms of irritation, for example. Good indoor air and an indoor environment that supports health and well-being require more than just a lack of contaminants: the premises should also be comfortable, easy to clean and well-suited to their purpose.

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) and radon (risk factor of lung cancer). Moisture damage is one of the many risk factors of asthma. The health effects of all these contaminants are related to the amount 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.

Read more: The health impacts of indoor air

4. When are sealing repairs carried out?

Sealing repairs help prevent air from leaking indoors through the soil or damaged structures. Sealing repairs are carried out if, for example, removing microbial damage from structures is not possible due to matters such as the damage’s location or causes related to the building’s protection. Sealing repairs are also performed as urgent measures that help secure the premises’ use.

In postponing repair projects, the aim of sealing repairs is usually to ensure that the premises can be used until their renovation or another extensive repair, during which the damaged structures are usually renewed.

The aim of renovations and modernisations is always to primarily improve the airtightness of structures. However, actual sealing repairs are only carried out for well-founded reasons, such as due to the building being protected.  

Sealing repairs are always carefully planned, and their success is usually ensured with at least two traces tests, carried out at random spots. In a tracer test, tracer gas is fed into the repaired structure. Then, a gas gauge will be used to measure whether the structure has any air leaks.

5. What are air leaks?

Air leaks refer to unsealed sections in the structures. These section can either be very small, pin prick-like leaks that can only be detected with tracer tests, or larger gaps or cracks in the material, which can also be detected in a visual examination. Air leaks usually occur at bushings of wires or pipes and at joints of structures, such as joints between windows and walls.

 The principle is that the structures should be sealed. For example, if air leaks indoors through the bottom floor’s floor structure, contaminants from the crawls space or soil can carry to the indoor air if the indoor premises are depressurised.

 The effect of air leaks on indoor air depends on the structures’ condition as well as on whether the leaks come through the structure or straight from outside air, for example.

 Contaminants travelling in the air leaks may include, for example, 

  • fine particles and other contaminants in outdoor air 
  • abnormal microbes in structures
  • other contaminants such as dirt that has accumulated in the structures
  • microbes and radon in the soil 
  • microbes in organic matter left in the crawl space
  • cigarette smoke from the neighbouring premises or outside.

6. When will the operations move to temporary facilities?

Operations are usually moved to temporary facilities before any major renovation projects. The need for these facilities is known well in advance in planned and scheduled renovation projects. Sometimes, moving to temporary facilities must be done quickly, if continuing operations in the old facilities is not possible due to water damage, for example.

The City will also start to look for temporary facilities if the condition survey reveals that the necessary extensive repairs will take too much time and measures that can be implemented quickly would not improve the situation enough. 

7. How long will it take to get temporary facilities?

Acquiring suitable temporary facilities may take from weeks to months, depending on whether the operations will be moved to them in full or only partly. Whether suitable premises are already available also affects the schedule.

Primarily, the first option reviewed is whether the operations can be moved to another space within the building or, alternatively, to another business or service location. The second option is to review the City’s own, empty facilities that would be suitable for the purposes. If none are found, temporary rental facilities from other providers will be reviewed. If none are found, again, the option to set up a temporary pavilion will be reviewed. When only a part of a building is to be repaired, a ‘dry pavilion’ without water points or toilet facilities can also be considered.

Usually, temporary facilities are not ready to move into, and they have to be redesigned and renovated to suit the operations or the pavilions need to be ordered from an external supplier. Stages that take a great deal of time in pavilion projects include tasks such as finding a suitable location, the potential exemption permit procedure related to zoning, tendering for the building process, acquiring a building permit, civil engineering and organising water, sewer and power connections.

8. Who can prohibit the use of a facility and in what circumstances?

The prohibition on using the premises is an administrative constraint, which allows the control authority (e.g., the health protection authority or Regional State Administrative Agency) to prohibit the use of the premises.

The Urban Environment Committee’s Environment and Permits sub-committee acts as the municipal health protection authority in Helsinki, and is therefore the body that may prohibit the use of a facility if the property owner or operator has not taken action to remove the hazard or limit the use of the facility. Only the sub-committee can allow the facility to be used again. A prohibition may also be placed on a part of a building or an individual space.

Factors causing the use of a facility to be limited include, for example, exceptionally high radon content, presence of asbestos, radiation danger, severe microbial damage, contaminated drinking water, or strong smell of cigarette smoke. Every case is considered individually and assessed as a whole.

In general, the use of City of Helsinki’s premises is not limited by constraints. Instead, the building owner or operator remove the premises from use, if needed.

9. Are the premises healthy and safe after the repairs?

Primarily, premises are healthy and safe when the sources of contaminants, causes of damage and the damaged structural parts discovered in the building have been removed or repaired so that they are not in contact with indoor air. This requires that the premises with issues have been comprehensively investigated and any detected defects and deficiencies have been properly rectified. In the City of Helsinki’s buildings, an attempt is made to locate and repair contaminant sources of indoor air extensively by utilising information received through the building’s condition investigation, for example. 

10. Why do the symptoms continue even though the premises have been repaired? 

Sometimes, the symptoms of individual people may persist even after thorough repairs. In addition to the sources of contaminants, several other factors affect the experienced quality of indoor air, such as comfort of the premises, their functionality and their suitability for the purpose.

Itis important to consider that symptoms and illnesses are always a sum of many parts, not only caused by contaminants. Factors that affect them include, for example, the person’s immune defence, risk perceptions, general state of health, lifestyle and social aspects. Accodring to research, symptoms may increase if the person feels that indoor air is detrimental, as experiencing a threat triggers a stress reaction in the body, which leads to physiological responses.

If the symptoms persist despite the repairs, the people exhibiting symptoms can be helped with individual measures, such as offering them the chance to move to other premises or different service location. The causes of the symptoms and means of recovery will be reviewed together with healthcare services. The symptoms should also be reported to the site’s supervisor, who will forward the information to the premises’ maintenance service provider. An indoor air specialist will assess the success of the repairs together with other parties, after which the decisions on how to rectify potential defects will be made.

11. When and how furniture and other movable objects will be cleaned during the move?

Normal dust and dirt on movable objects should always be cleaned during the move, even if there is no indoor air problem in the premises. Unnecessary movable objects will be disposed of or recycled.

The need to deep-clean furniture and items may occur if investigations have revealed microbial damage, fibre sources or other contaminants that are getting stuck to the furniture in the building, and the items will be moved to other premises either urgently or as planned. The site’s indoor air specialist will determine the cleaning needs together with other parties, based on the quality and extent of the indoor air problem.

The City of Helsinki has its own set of guidelines for cleaning movable objects, which are based on the instructions from the Finnish Institute of Occupational Health. If the furniture and movable objects have no visible mould or obvious odour, their careful cleaning is usually enough, based on these guidelines. Hard surfaces can be vacuumed and cleaned, and textiles should be washed at 60°C or over or taken for chemical cleaning. Textiles, padded furniture and similar with clear spots or odour of mould must be disposed of. 

12. What is radon and why is it measured?

Radon is an odourless, tasteless and colourless radioactive noble gas that occurs in the Earth’s crust as a degradation product of uranium and thorium. Radon’s radioactive degradation products increase the risk of lung cancer. After smoking, radon is the second most common cause of lung cancer in Finland. The radon concentrations of indoor air are higher in Finland than in most other countries due to geology, building technique and climate. Radon can carry to indoor air through cracks in the building’s floor structures.

The reform of the Radiation Act in December 2018 made radon measurements mandatory in Helsinki. In areas with mandatory radon measurements, radon concentrations must be reviewed in workplaces that are located in a building’s basement and on the first floor. The employer is responsible for carrying out the measurements. The objective of radon measurements is to review the radon concentrations in the premises so that the users’ exposure to radon can be reduced if necessary.

The radon concentrations measured in the City of Helsinki’s workplaces have mostly been at a low level. The limit value defined for radon was exceeded at approximately 6% of the sites where measurements were carried out during terms 2018–2019 and 2019–2020. Additional measurements were carried out in these locations, and it was discovered that the radon concentrations usually remained at a low level when the ventilation system was on.

13. What are the microbes in indoor environments and how do they affect our health?

Microbes in indoor environment refer to, for example, bacteria, moulds and yeasts. In layperson’s terms, all of these are usually referred to as mould. Microbes and their metabolites are always present both indoors and outdoors. Microbe concentrations and species vary depending on the conditions, such as the season. The microbe concentration of indoor air is affected by factors such as the microbe concentration of outdoor air, dust, human actions and humans themselves, and microbial damage. It has been discovered that the microbes in our living environment also have beneficial health effects, which means that not all microbe exposure is detrimental.

Unrepaired moisture damage in a building is one risk factor of respiratory tract symptoms and asthma, according to studies. However, it has not been possible to discover the causality between moisture damage and health effects, as it is not known which factors and mechanisms cause these health effects. Due to this, establishing limit values for individual microbe species or results from microbe samples based on the health impacts has not been possible. No risk has been identified for the development of other diseases.

14. What are actinomyces and are is their occurrence in a building detrimental to health?

Actinomyces are bacteria that grow hyphae and endospores, similar to fungi. Actinomyces are also called actinobacteria. The species include streptomycetes, for example. Actinomyces are very common microbes in the environment and have important roles to play in nature. Actinomyces are very common in soil, and are often characterised by the smell of earth and basement. Actinomyces can carry indoors on people’s shoes or outdoor clothing, for example. 

When growing inside structures, actinomyces are one ‘indicator microbe’ of moisture damage, as they enjooy moist surroundings. Moisture damage provides many different species of microbes with good growth conditions. Small quantities of actinomyces may also carry to structures as a result of air leaks, for example.

The detrimental effect of actinomyces on the users of the premises is assessed in the same way as for other microbes discovered in investigations. 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. 

15. What are VOC and TVOC?

The abbreviation VOC comes from the words volatile organic compounds. TVOC refers to the measured total volatile organic compounds.

Indoor air always has small concentrations of as many as hundreds of different volatile organic compounds, which come from sources such as building materials and fixtures, cleaning substances, consumer goods and people themselves. New materials, in particular, release more volatile organic compounds than old materials, but their quantity usually lowers to the standard level within 6–12 months. Improved ventilation will speed up this process.

VOC concentrations may also be elevated if materials have gotten wet, have default emissions that are too high or are aging. The concentration of VOCs may also be temporarily elevated after the premises are cleaned, and this is quite common.

Limits have been set for total volatile organic compounds in indoor air as well as for four individual compounds in the Housing Health Decree, and measures need to be taken if these limits are exceeded. The Finnish Institute of Occupational Health has also determined reference values for certain individual compounds, which indicate whether the concentrations of these compounds are at a normal level.

VOCs in indoor air can be one cause of temporary irritation and respiratory tract symptoms, and they may also cause odour problems.

16. Do VOC measurements detect all chemicals in indoor air?

They do not. VOC measurements only detect volatile organic compounds with a boiling point of 50–250  oC. These compounds occur as gases in indoor air.  

In addition to VOCs, semi-volatile organic compounds (such as PAH compounds), highly volatile organic compounds (such as acetone, formaldehyde and alcohols) or particle-bound compounds can occur in indoor air in certain situations. Separate methods are needed to measure the concentrations of these substances. 

Aside from the organic compounds, air can also contain inorganic compounds, such as carbon monoxide, carbon dioxide, ozone, oxides of nitrogen, sulfur compounds or ammonia.

17. What are PAH compounds and what kind of health impacts do they have?

PAH compounds, i.e. polycyclic aromatic hydrocarbons, are by-products of incomplete thermal decomposition. They can carry to indoor air from sources such as cigarette smoke outdoors and creosote, which is often identified by its smell of a railway sleeper. Creosote was used in older buildings as water and moisture insulation (bituminous paper, asphalt roll membrane). It has also been used to saturate wood in outdoor structures.

Most PAH compounds are generated as emissions by traffic, industry and energy production (such as small-scale wood burning) as well as in nature during forest fires, for example. They are also present in food, such as grilled or smoked dishes. 

The quantity and duration of exposure affect how the health effects are created, as does the method of exposure (e.g. by digesting, breathing or touching the compound). PAHs are a large group of different compounds with varying health impacts. The health effects of the lightest compound, naphthalene, and the heaviest compound, benzo[a]pyrene, have been studied the most extensively. Limit values requiring actions have been issued for these in the Housing Health Decree. The benzo[a]pyrene concentrations of outdoor air are monitored in the Helsinki Metropolitan Area. 

18. Which methods are used to investigate buildings’ microbial damage?

Primarily, extensive technical surveys of indoor air and moisture condition are carried out in the buildings, during which microbe samples will be taken of the construction materials. The advantage of these construction material samples is that they help locate the microbial damage as well as review its extent.

The surveys are started by reviewing the structural drawings and locating the areas vulnerable to moisture and by holding an initial site review 

Microbe samples of materials are not always necessary, if the growth can be seen with the naked eye. For example, the moisture and microbial damage detected in connection to water damage can sometimes be repaired without investigations. Moisture and microbial damage must always be repaired, regardless of the results of the sample.



10.09.2021 13:05