Hospital airborne infection prevention

A Norwegian research project in under progress to develop a new concept for control of air movements in protection isolates, operating theatres and other risk areas in hospitals. The aim is to reduce airborne hospital infections through appropriate design of building, HVAC installation and control of air movements. A container solution was developped for isolates. Its HVAC system, and especially the ventilation system are described in details. The first container has been finished in June 2002 to be tested.

The impact of air pollution from used ventilation filters on human comfort and health

In an environmental lab with a panel of 30 women exposed 4 hours, comfort and health have been detremined both with a used or a new filter present in the ventilation system. All other environmental parameters were kept constant. A used filter in a HVAC system can have a negative effect on both the immediate perception of the indoor air quality and on perceptions and health-related symptoms. However, the annoyance experienced through the sensory system may have amplified the intensity of symptoms.

Linkages between outdoor and indoor air quality issues : pollutants and research crossing the threshold

Relationships between research about indoor and outdoor air quality are reviewed. The author mentions that outdoor air pollution has attached greater regulatory interest, although people spend more time indoors. The contribution of exposure to indoor pollutants is now more recognized but this increased consideration has little effect on regulations. Nevertheless, the author considers that indoor air quality researchers and public health officials have a lot to learn from the outdoor air quality experience, in fields such as exposure, dosimetry, health effects and risks, mixed exposures.

Comparison of operating room ventilation systems in the protection of the surgical site

The risk of contaminant deposition (10 microns particles) on an operating room surgical site is evaluated for different ventilation systems - conventional, laminar, non-aspirating, displacement -, using airflow modeling and particle tracking methodologies. Results show that laminar flows are the most appropriate to avoid particles deposition.

Outbreak of Japanese encephalitis on the island of Saipan, 1990.

This was a study of the possible causes of an outbreak of encephalitis on Saipan in October 1990. The virus was not isolated but patients seroconverted to Japanese encephalitis (JE) virus, suggesting the first known outbreak of the disease on American territory since 1947. Ten cases were found in a population of 40,000. In a survey after the outbreak, the prevalence of antibody to JE virus was 4.2% among 234 native Saipan residents. Risk factors for infection were age, crowded living conditions and lack of air conditioning.

The feasibility of using a double blind experimental cross-over design to study interventions for sick building syndrome.

The study of the causes of Sick Building Syndrome and its possible solutions have been bedevilled by methodological problems. This pilot study assessed the viability of using an expermental double blind cross-over study to overcome such difficulties. The experiment involved varying the rate of supply of outdoor air from 10 cubic feet per minute per person (cfmpp) to 20 cfmpp or 50 cfmpp by controlling the building's heating, ventilation and air-conditioning (HVAC) systems.

Air conditioning and health: effect on pulse and blood pressure of young healthy Nigerians.

This research studies the effects of air conditioning on blood pressure and the heart rate. It is based on studying the blood pressure and pulse of 32 young healthy Nigerian volunteers after they had been in an air-conditioned room from between 60 and 90 minutes. The same measurements were made under the same conditions with the air-conditioning switched off. The mean systolic blood pressure (SBP) was 115.3 +/- 11.5 mm Hg with air conditioning (AC) and 108.5 +/- 10.1 mm Hg without air conditioning. This difference was statistically significant.

Influence of indoor climate on the sick building syndrome in an office environment.

The role of indoor climate factors on symptoms of the sick building syndrome was studied in Copenhagen, Denmark. Altogether, 2369 office workers completed questionnaires in 14 buildings, whose indoor climate was measured. The results were subjected to multivariate logistic regression analyses of the multifactorial effects on the prevalence of work-related mucosal irritation and work-related general symptoms among the office workers.

Work-related illness in offices: a proposed model of the "sick building syndrome".

This study was based on a nationwide survey of 4373 workers at 47 offices to determine the incidence of sick building syndrome and to study associated factors. The buildings had a variety of ventilation systems - natural, mechanical, forced air, air conditioning or comfort cooling. Comfort cooling systems included fan-coil, induction, and constant or variable air volume systems.