Reactions among pollutants in the intake air can increase the concentrations of irritating and hazardous products in the indoor air and may lead to an increase of the sick building syn-drome (SBS). A short description of an experimental set-up that enables the studies of the impact of different settings of a full scale ventilation system on air with different ambient compositions is presented. Preliminary sampling using Tenax TA show that some reaction rates are increased in the experimental set-up, which could indicate that heterogenous reactions occur.

Particle number concentrations and size distributions were measured in the living room of an unoccupied apartment located in a street canyon in central Copenhagen, in the street, and at a nearby urban background station. A simple dispersion model was used to calculate the particle concentrations outside a window facing the street from where most of the ventilation air was supplied. The penetration efficiencies and the deposition rates were estimated using the concentration rate balance, ignoring indoor sources.

Accurate characterization of particle concentrations indoors is critical to exposure assessments. It is estimated that indoor particle concentrations depend strongly on outdoor concentrations. For health scientists, knowledge of the factors that control the relationship of indoor particle concentrations to outdoor levels is particularly important. In this paper, we identify and evaluate sources of data for those factors that affect the transport to and concentration of outdoor particles indoors.

Irritative and respiratory symptoms are reported from people working or living in damp and mouldy buildings, but signs of pulmonary involvement have not yet been found. We studied 522 teachers working in 15 primary schools with various degrees of dampness and mould growth. Symptoms, spirometry, CO-diffusion, and bronchial challenge was compared to classification of dampness and mould growth in or outside classrooms.

Authors assessed building-related risk factors for lower respiratory symptoms in office workers. The National Institute for Occupational Safety and Health in 1993 collected data during indoor environmental health investigations of workplaces. Multivariate logistic regression analyses were used to assess relationships between lower respiratory symptoms in office workers and risk factors plausibly related to microbiologic contamination.

The paper deals with air flow visualisation using fog generators. This technique has been applied to show air jets boundaries in several cases, in order to design flow generating equipment in industrial buildings.

Computed tomography consists in measuring chemical concentrations profiles in a room from the attenuation of a large number of laser rays and converting measurements in a two dimensional concentration profile by a reconstruction algorithm. This study shows the effectiveness of one of these algorithms (Low Third Derivative).

This paper defines a new parameter : the equivalent frequency used for the description of the frequency characteristics of air velocity in turbulent flows.Analyses were performed to identify how much the accuracy of determination of the equivalent frequency depends on the characteristics of the velocity. Results of the analyses identified that the equivalent frequency of the velocity fluctuations in rooms is between 0.1 et 1 Hz, and 90 % of those records were between 0.2 and 0.6 Hz which is the frequency range identified to have most significant impact on people's draught sensation.

Three methods : step-up velocity change, step-down velocity change, and the cut-off frequency method were tested for the dynamic response of two low velocity thermal anemometers.This paper had the objective to identify whether those methods recommended in the standards and guidelines always succeed in determining accurately the frequency response curves and the time constant of low velocities anemometers.

In order to identify the complex flow located at the breathing zone of a seated person exposed to the airflow coming form a PVS (personalized ventilation system) two techniques are used and compared : the PIV ( a two-dimensional particle image velocimeter) and the LDA (laser doppler anemometer) technique with a single point measurement, given by a cross section of laser beams.
The PIV technique appears a very interesting tool in studies aiming at identifying airflow in rooms or around objects.