English

Describes a study carried out to investigate the possibility of suppressing microbial contamination of circulating water in humidifiers by using the oligodynamic potential of silver ions. Puts forward basic hygienic requirement to ensure adequate quality of water in humidifiers of air conditioning plant.

Following a sensory panel assessment of perceived air quality, proposes the use of a simple measurement method based on a dilution system connected to a ventilated small-scale test chamber in order to characterise the emissions from materials in sensory and chemical terms.

Explores possible relations between symptoms of asthma, building characteristics and indoor concentration of volatile organic compounds in residential buildings. 88 persons from middle Sweden were studied. Measurements were taken at home of room temperature, air humidity, respirable duct, carbon dioxide, VOCs, formaldehyde and house dust mites. Health tests were also performed. Found that symptoms related to asthma were more common in homes with house dust mites and visible signs of dampness or microbial growth.

Describes a study of the emissions from five commonly used building products: three floor coverings - PVC, floor varnish on beechwood parquet and nylon carpet on a latex foam backing; an acrylic sealant and a waterborne wall paint on gypsum board. Small scale test chambers were used over 50 days. A sensory panel was used to assess odour intensity and VOCs were measured. Emissions were studied under two or three different area-specific ventilation rates.

The most important indoor particle sources in the four single family homes studied were found to be cooking, cleaning and the movement of people. The sources contributed significantly to indoor concentration and to altered indoor particle size distributions. Air exchange rates ranged between 0.12 and 24.3 ach and impacted on indoor particle levels and size distributions.

States that in January to April 1989, over 90% of greater Montreal day car centres exceeded 1000 ppm of carbon dioxide. Independent positive predictors were the child density, presence of electric heating, absence of a ventilation system and age of the building. Recommends that clear standards and inspection policies should be set for day care centre air quality.

Relates exposure measurements for indoor air quality in schools to perception of IAQ by employees. A questionnaire was used to gather information on subjective air quality, domestic exposures and health aspects. 38 schools were covered in the study. A 53% section of personnel reported bad or very bad indoor air quality. Worst reports came from the younger personnel, those dissatisfied with their psychosocial work climate and those not exposed to domestic tobacco smoke. Less IAQ dissatisfaction was reported for older schools and those with displacement ventilation.

States that schools often have a low air change rate. The study attempted to find out if an improvement in school ventilation would lead to improved health in pupils. A questionnaire was set for 1476 primary and secondary school pupils in 39 schools. 100 classrooms were monitored. New ventilation systems were installed in 12% of the classrooms over the survey period, increasing air change rate and reducing relative humidity and occurrence of a number of airborne pollutants. The study found that reporting of asthmatic symptoms decreased in the schools with new ventilation systems.

Describes a longitudinal study of 83 social workers in two office building in Sweden. The exposed group moved to a newly redecorated building nearby, using low emitting building materials and solvent-free paint. Findings indicated that the move resulted in an increase in the personal outdoor airflow rate. The move resulted in increased nasal patency and ECP and lysozyme in NAL. Concludes that no major ocular or nasal effects or measurable increase in indoor air pollution need to result from redecoration of a well-ventilated building, if low emitting materials are chosen.

A study was done to find a link between bronchial obstruction in infants under two years old and ventilation rate in residential buildings. A matched case control study was carried out in Oslo over two years. It was found that the risk of bronchial obstruction was not directly associated with the ventilation rate in litres per second and per person. Environmental tobacco smoke affected the incidence of bronchial obstruction, as well as dampness, presence of textile wallpaper and plasticiser-containing surfaces.