Airborne microbial contaminants in indoor environments. Naturally ventilated and air-conditioned homes.

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.

Monitoring of bacterial sugars and hydroxy fatty acids in dust from air conditioners by gas chromatography-mass spectrometry.

A study examined by chemical analysis (without prior culture) bacterial levels in dust collected from hospital air conditioning filters. Gas chromatography-mass spectrometry methods were used to analyse the dust. Concludes that there is potential for the chemical assessment of the microbial content of airborne dust.

Bacterial fouling of a hospital closed-loop cooling system by Pseudomonas sp.

Deterioration of air conditioning system in a hospital in Boston was found to derive from a strain of Pseudomonas sp. on heat transfer tubes of the closed chilled water system. Growth was stimulated by ethylene glycol antifreeze. The source was a warm expansion tank. The organism has been related to hospital-acquired infections.

Comparison of indoor climate and microbial contamination in two office buildings with different ventilation systems.

Describes a survey carried out to investigate microclimatic conditions and microbial contamination in two office buildings with and without central air conditioning. Measured indoor climate factors generally fell within acceptable ranges for the mechanically ventilated buildings, except for the winter sample where relative humidity was low. Microclimatic parameters showed seasonal variation in the naturally ventilated building, and bacterial and fungal contamination was higher.

Microbial growth control in spray humidifiers of health facilities.

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.

Numerical study on minimizing risk from airborne organisms in hospital isolation rooms.

This study utilizes Computational Fluid Dynamics (CFD) and particle tracking procedure to study the effects of ventilation system and ultraviolet germicidal irradiation (UVGI) on minimizing the risk from airborne organism in isolation rooms.

Standards for hygiene.

Explores the complexities of guidance for the ventilation of hygiene systems. The UK Health & Safety Executive estimates that 30 to 50% of refurbished buildings cause some form of sick building syndrome. It is obviously important that building managers take the necessary steps to establish programmes to maintain ductwork systems in a safe, effective and hygienic state. The UK Heating & Ventilation Contractors' Association and Building Services Research & Information Association have produced documents providing guidance on the hygienic maintenance and cleaning of ductwork.

The threat posed by airborne micro-organisms.