The article presents IAQ requirements for healthy office buildings in Nordic climates, based on the results of an epidemiological study of a multistorey office building in Helsinki, Finland. Summarizes the results of the study and gives recommendations and their limitations.

Investigates IAQ by making subjective assessments of perceived air pollution caused by human bioeffluents. A panel comprising 107 people reported on odour intensities and acceptability of bioeffluents from 54 other people as occupants. Twenty per cent of the judges described dissatisfaction caused by bioeffluents at 1.5 on the Yaglou's odour intensity scale. To satisfy 80% of the judges entering the chamber, a ventilation rate of around 7 litres per second per person was necessary.

An evaluation of the effect of air humidification on various factors was performed, including skin dryness and mucosa, allergic and asthmatic reactions and perception of IAQ. A six period cross over trial was conducted on 290 office workers. A total of 211 workers who returned at least two weekly diaries and who had experienced both humidified and nonhumidified conditions were included in the analyses. The main outcome was characterized by dryness, irritation or itching of skin and eyes, of the throat and nasal dryness.

Describes a study of air humidification in the Pasila Office Center, which is a modern eight-floor office buildings of 2150 workers in Helsinki, Finland. A comparison was done between the occurrence of symptoms and complaints among the workers in the humidified part of the building and the symptoms and complaints of workers in similar nonhumidified rooms during February, March and April. Significantly less dryness of skin, throat and nose and nasal obstruction as well as sensation of air dryness was reported by the workers in the humidified part.

The aim of the study was to evaluate the effect of humidification on the odour, acceptability and stuffiness of indoor air. The air of two wings of an office building in turn were ventilated with air of 30%-40% humidity in a six period cross over trial. The third wing was used as a non-humidified control. A panel assessed the quality of indoor air weekly. Mean intraindividual differences were used to assess the roles of sex, current smoking and age. The study found that humidified air was regarded as more odorous and stuffy than non-humidified air.

The ventilation system of a community hospital deteriorated progressively over a period of years until it no longer met regulatory guidelines. The publicly funded military facility hospital asked for funding for repairs but they were not available. The funding request was met when an increase in infections was identified and high-risk operations had to be curtailed. The problems were solved entirely when the new ventilation system was in place.

The study compared the atmospheric burden of viable particulates in the interiors of condominium homes with central air conditioning with that of the typically more open type of naturally ventilated Hawaiian residence. Enumeration of the numbers and types of respirable fungi and bacteria inside were done using Andersen microbial air samplers. To evaluate the impact of the air conditioning system on indoor air quality the results were compared with those obtained outside the homes.

The survival of bacterial and mould spores in new and used air filter media is explored. Samples of different media were challenged with specific microbial aerosols in a filtration test unit, and the viability of the microorganisms collected in the filter media examined. In five days there was no noticeable decrease or increase in the viability, nor did relative humidity have an influence.

In seven hospitals in the eastern United States air filters of various types, selected by discoloration, were collected from the primary and secondary filter banks of the HVAC systems. The samples were then examined with direct microscopy for fungal colonization. Results showed that filters from five of the hospitals were colonized with fungi. Several of the species had not previously been reported to colonize air filters.

Describes how new and used cellulosic air filters for HVAC systems including those treated with antimicrobials were suspended in vessels with a range of relative humidities, and containing non-sterile potting soil to stimulate fungal growth. Prior to suspension in the chambers most filters yielded fungi, but only two of 14 non-treated filters demonstrated fungal colonization following use in HVAC systems. Antimicrobial-treated filters, in particular a phosphated amine complex showed a lot less fungal colonization than nontreated filters.