With the Aattela Method, the total indoor air toxicity of a building can be determined quickly, reliably and inexpensively.


The Aattela Method is used to find out the overall toxicity of a building. Based on the result, a decision can be made about the need for further research. The Aattela Method is the only indoor air quality research method based on cellular toxicology.

The cytotoxicity/cellular toxicity analysis is always performed in six parallel tests to ensure that the result is also statistically reliable. Since 2016, the Aattela Method has been used to test the indoor air quality at hundreds of sites.

Human macrophage cells, which play an important role in the immune defense system, are used for the analysis. The result shows how effectively the indoor air sample kills human macrophage cells.

Indoor air pollutants occur and enter the body in three different states.

  • Particles (solid matter) such as asbestos, fibers, animal dander, pollen, spores, bacteria, viruses, and nanoparticles.

  • Gases, such as carbon monoxide, carbon dioxide, ammonia, nitrogen dioxide, hydrogen sulphide, ozone, formaldehyde, radon, volatile and highly volatile organic compounds (VOCs, VVOCs) and polycyclic aromatic hydrocarbons (PAHs).

  • Liquids (mists, vapours).

Different states require different collection methods

A comprehensive study of the building is necessary when studying indoor air problems. Indoor air toxicity measurement is an essential and important part of this. Particulate matter and gaseous pollutants have been researched for almost 30 years. The research of liquid contaminants only became possible with Johanna Salo’s diploma thesis (2014) and the development of Aattela Sampling Method (2015).

Liquid pollutants in indoor air include, e.g., toxins produced by molds, products of microbial metabolism, biocides in materials, active substances in detergents and cleaning agents, and nanoparticles produced by traffic. These contaminants move with the water vapour in the air and therefore a water sample must be collected directly from the indoor air.

Toxic metabolites excreted by molds into the room air are much more harmful than dusts containing molds. Lungs have no protective mechanism against toxins, so they are absorbed directly into the lung tissue. Our environment contains bacteria, molds and fungi and their metabolites. Most of them are useful and harmless, but some of the metabolites are toxic and cause cell damage and cell death, together with various symptoms such as shortness of breath, fatigue, inflammation and headaches.

The Aattela Method enables collecting indoor air samples throughout the year

Based on the result, clean rooms can be distinguished from damaged rooms. Latent damage can be identified without breaking the structures. The method also shows whether the repair has had the desired effect on indoor air quality.

Indoor air toxicity measurements should be taken every two years. When damage is detected at an early stage, the extent of the damage and the cost of repairs are minimized, and potential health damage prevented.


Sisäilmatutkimuspalvelut  Elisa Aattela Oy has developed an innovative indoor air measurement method and sampling system. In the new patented Aattela Measurement Method, frost water is collected on the cold surface of the E-collector using dry ice.

The Aattela Method is reliable and reproducible, and samples can be collected all year round. The method can also be used for testing other factors affecting indoor air. The future will show other possible areas for research.

The patent is worldwide, both for the device and the method.

The Aattela Method determines the indoor air quality of an apartment or building quickly and affordably

  • Upon completion of the building

  • In connection with the 2- and 10-year inspection of the building

  • When making a lease

  • When the ownership of the building changes

  • When in doubt about indoor air quality

  • When symptoms occur

The final conclusion of the Toxtest research project was published at an indoor climate seminar in March 2013. It stated that indoor air toxicity should be studied directly from indoor air and not from indoor dust. For example, active sample collecting directly from the air could be a more preferred method of sampling than a dust sample. Inspired by this, a group of researchers set out open-mindedly in search of a new method.

The team tested dust collection methods on ventilation filters and air purifiers, and installed separate laboratory filter papers on the air purifiers. These were then tested for indoor air toxicity. However, this was not a functional method because it took a long time to collect the samples.

In the spring of 2014, Johanna Salo’s diploma thesis was published at Aalto University; she had tested the indoor air toxicity in condensed water that was collected from indoor air. Inspired by this, the development done in the autumn of 2014 gave rise to a new innovative idea to collect water from indoor air by frosting, and to test indoor air toxicity from it.

The goal was to develop an indoor air research method that can be used year-round to produce reliable, reproducible, and consistent analyzes in different laboratories. This was the beginning of the Aattela Measurement Method, in which carbonated ice (-79 ° C) is placed inside a steel box (i.e. E-collector).

The water vapour in the indoor air is frosted on the cold surface of the E-collector. The carbonated ice is removed and frosting ceases. The frost turns into water and drains onto the tray under the steel box. The water is transferred to a sample bottle and delivered to the laboratory for examination.

The Aattela Measurement Method was tested at 30 real damage sites in the autumn of 2015. Identical samples were submitted to two universities. The University of Turku performed the analyzes with E. coli-lux bacteria they had developed, and the University of Helsinki tested the samples with porcine spermatoza. When the results were consistent, commercial operations could be started in 2016.

The Aattela Indoor Air Research Method can be used to prioritize property repairs. In a sales situation, a reliable indoor air test result helps both the seller and the buyer to find out possible damages hidden in the structures.

Contaminants formed in the damaged structure pass through the structures into the indoor air, and toxicity is reflected in the frost water sample. The indoor air measurements made before and after the repair indicate whether the indoor air has been cleaned as a result.

Finnish companies using the Aattela Method

Selexlab Oy

Kirsi Vaali
040 170 3031
Kalevankatu 17 A
00100 Helsinki

Southern Finland

Vesito Oy

Vesa Toiviainen
040 7509 832
Bostoninkaari 3 C 16
04320 Tuusula

Southern Finland

VARA Palvelut Oy

Teijo Niinimäki
+358 44 308 7375
Vapaalantie 8A
01650 Vantaa

Southern Finland

TPI Control Oy

Karin Paavilainen
+358 400 403 460
Juurakkotie 5 A
01510 Vantaa

Southern Finland

TPI Control Oy

Karin Paavilainen
+358 400 403 460
Myllyhaantie 2
33960 Pirkkala

Western Finland

KLV-palvelut Oy

Markku Laine
+358 50 433 4342
Köydenpunojankatu 14
20100 Turku

Western Finland

Suomen Laatuilma Oy

Kari Hakamaa
+358 40 176 9733
Teknologiapuisto 1
61800 Kauhajoki

Western Finland

Insinööritoimisto ReCon Oy

Markku Varsanpää
+358 50 300 7570
Vaasanpuistikko 18 4 krs
65100 Vaasa

Western Finland

Kotikeskus Kodin Onni Oy

Timo Kortesmaa
+358 45 883 0773
Hiukkaan kylätie 110
35400 Längelmäki

Central Finland

Sospiro Oy

Juha Kinnunen
+358 500 577 989
Kiikarikatu 28
80160 Joensuu

Eastern Finland

Meranti Siivouspalvelut Ky

Marianne Tuomainen
Haaransuonkuja 10
90240 Oulu

Northern Finland