Indoor Air Quality Control

Principal investigator: Kristina Saarela, M.Sc.,VTT Chemical Technology, Environmental Technology, E-mail:

Population exposure and to air pollution caused by different chemical compounds and to annoying odours inside buildings is usually much more significant than outdoors due to higher concentrations and overall longer periods of time spent indoors. As the indoor air quality (IAQ) has a non-negligible impact on human health and comfort, a healthy indoor climate should be one of the main objectives of today's construction practise. This, however, requires development of comprehensive and effective ways for characterisation of the air indoor and related symptoms. Until now, only a few health effect studiesconcerning the health and discomfort effects of indoor air have been carried out. Indoor air is strongly affected by the surrounding building materials releasing a wide variety of chemical compounds such as volatile organic compounds (VOCs), aldehydes and ammonia, which are suggested to cause several types of health effects and discomfort. As only little knowledge of material emissions and their health and acute discomfort effects is currently available and as there is no consensus on the harmful chemical compounds, source emission control is currently considered the most effective control option. Some classification systems, such as Finnish 'Classification of Indoor Climate, Construction, and Finishing Materials' are already been promoted. The development and use of new healthy materials however requires deeper understanding of material emissions and their correlation with perceived indoor air quality, personal health and well being.

The first aim of this research is to establish the causal connection between the diagnosed health effects and the chemical composition of indoor air. Based on this knowledge, criteria for good indoor air may be created. The second significant aim is to generate more health and comfort related IAQ and material emission evaluation procedures to be utilised in indoor air diagnostics and material classification purposes. These aims can be achieved by the following research tasks:

simultaneous production of health effect and IAQ data

understanding of causal connection of both indoor and outdoor emissions and their impacts on personal health and well-being through modelling and with the help of an extensive database

development of comprehensive chemical measurement and sensory evaluation techniques, complementary to currently used ones, for IAQ and material emission control

implementation of new testing procedures for indoor air and material emissions

prediction of IAQ from material emission data with the help of a model, which takes into account also the physical

parameters, e.g. ventilation rate and sorption effects

The first task is aimed at establishing criteria for healthy indoor air. This is obtained by combining the existing data from

VTT's IAQ-database, the indoor air data from EU-Expolis study and comprehensive health related data, which is obtained by choosing subjects among the patients treated in Helsinki University Central Hospital because of building related symptoms. The health and comprehensive indoor air data obtained from the subjects and their homes are compared with similar data of a control group. For collecting the comprehensive indoor air data new methods are utilised in order to detect very volatile (VVOCs) and semi-volatile organic compounds (SVOCs) and polar compounds.

The aim of the second task is to develop procedures to evaluate the irritating and odorous chemical compounds of material emissions and the perceived air quality. The causative relationships between sensory assessment method used in the present Finnish Classification of Finishing Materials, olfactometry and emission measurements in chemical terms are determined. The irritate data is produced in a study "Irritating properties of emissions from building materials" co-ordinated by University of Kuopio. The data obtained in this study is combined with data from VTT's DAME database in order to create an evaluation method for the revision of the present Finnish Classification for Finishing Materials.

The third task is focused on establishing a modelling procedure for predicting IAQ based on material emission data. In order to create an IAQ model, a procedure for testing sorption effects in laboratory scale is established and material emission together with sorption data is produced.