mould

Thirty-nine houses with high levels of biologically active contaminants in Wallace burg, Canada, and twenty houses with low levels of biologically active contaminants, were subjected to field inspections and testing, monitoring of indoor environmental conditions, and simulation to predict the condensation formation potential in winter. Occupant health was evaluated through questionnaires and blood sampling from an index child (closest to age ten) for analyses of T-lymphocyte and B-lymphocyte structure.

In this study, we investigated the indoor air quality (IAQ) in classrooms with exhaustventilation systems and in naturally ventilated classrooms. In the latter, we found peak CO2-concentrations of more than 4000 ppm. 1500 ppm was exceeded during 40 to 86% ofteaching time, dependent on class size. The windows were opened rarely in winter which ledto low mean air exchange rates of 0.20 0.23 h^-1. The operation of mechanical ventilationsystems improved IAQ considerably. Peak CO2-concentrations decreased to less than 2500ppm. 1500 ppm was exceeded for only 7 to 57% of teaching time.

This study investigated the presence of allergens such as dust and molds in heat recovery ventilation systems and the duct work. It also looks at two different types of cleaning equipment and their ability to clean these pollutants from the rigid and flexible ductwork and heat recovery ventilator (HRV) cores in dedicated balanced supply and exhaust ventilation systems. Samples from the ductwork and cores of ten ventilation systems were tested for levels of dust and mold.

Three different techniques for reducing exposure to microorganisms were tested during remediation of moldy buildings. Concentrations of spores (fungi and actinomycetes) were determined by filter sampling before, during, and after remediation. The local exhaust method used for asbestos dismantling was the most effective control method. In the construction zone, concentrations of microorganisms were 4-25 times higher during remediation than before it. In the adjacent area no increase in concentrations was seen.