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At least 73 records · Page 4Linked to original sources
PubMed2004

Fungal endophthalmitis caused by Paecilomyces variotii following cataract surgery: a presumed operating room air-conditioning system contamination.

PURPOSE: To report a case of delayed fungal endophthalmitis by Paecilomyces variotii following uncomplicated cataract surgery. To our knowledge this is the first reported case of postoperative endophthalmitis by this species. METHODS: We report the longterm clinical follow-up of an 83-year-old female who underwent uncomplicated sutureless, small-incision cataract surgery. She developed recurring uveitis 4 months after surgery. Vitreous tap and finally complete vitrectomy with removal of the capsular bag including the intraocular lens were performed. Fungi were studied by histopathology and culture. RESULTS: At histopathological examination, the fungi were found to be closely related with the capsular bag. A few mononuclear inflammatory cells were encountered. At culture, Paecilomyces variotii, a common ubiquitous non-pathogenic saprophyte, was identified. Despite systemic, intravitreal and topical antifungal therapy after vitrectomy the uveitis recurred several times, but no fungal organisms were isolated from the repeat intraocular specimen. At 18 months postoperatively the subject's visual acuity was finger counting at 2 metres. At the time of surgery the operating room air-conditioning system was undergoing repairs. Cases of fungal endophthalmitis after contamination from air-conditioning ventilation systems have been reported before, but none of the cases reported have been caused by P. variotii. CONCLUSION: P. variotii, a non-pathogenic environmental saprophyte, may be disastrous if introduced into the eye. International recommendations on the environmental control of the operating room air-conditioning ventilation system should be strictly followed. No intraoperative surgery should be undertaken while the air-conditioning system is undergoing repairs or service.

Aged↗
PubMed2001

Ground performance of air conditioning and water recycle system for a Space Plant Box.

Researchers from 5 Japanese universities have developed a plant growth facility (Space Plant Box) for seed to seed experiments under microgravity. The breadboard model of the Space Plant Box was fabricated by assembling subsystems developed for microgravity. The subsystems include air conditioning and water recycle system, air circulation system, water and nutrient delivery system, lighting system and plant monitoring system. The air conditioning and water recycle system is simply composed of a single heat exchanger, two fans and hydrophilic fibrous strings. The strings allow water movement from the cooler fin in the Cooling Box to root supporting materials in the Plant Growth Chamber driven by water potential deficit. Relative humidity in the Plant Growth Chamber can be changed over a wide range by controlling the ratio of latent heat exchange to sensible heat exchange on the cooling fin of the heat exchanger. The transpiration rate was successfully measured by circulating air inside the Plant Growth Chamber only. Most water was recycled and a small amount of water needed to be added from the outside. The simple, air conditioning and water recycle system for the Space Plant Box showed good performance through a barley (Hordeum vulgare L.) growth experiment.

Air Conditioning↗
PubMed2001

Fault tree analysis for exposure to refrigerants used for automotive air conditioning in the United States.

A fault tree analysis was used to estimate the number of refrigerant exposures of automotive service technicians and vehicle occupants in the United States. Exposures of service technicians can occur when service equipment or automotive air-conditioning systems leak during servicing. The number of refrigerant exposures of service technicians was estimated to be 135,000 per year. Exposures of vehicle occupants can occur when refrigerant enters passenger compartments due to sudden leaks in air-conditioning systems, leaks following servicing, or leaks caused by collisions. The total number of exposures of vehicle occupants was estimated to be 3,600 per year. The largest number of exposures of vehicle occupants was estimated for leaks caused by collisions, and the second largest number of exposures was estimated for leaks following servicing. Estimates used in the fault tree analysis were based on a survey of automotive air-conditioning service shops, the best available data from the literature, and the engineering judgement of the authors and expert reviewers from the Society of Automotive Engineers Interior Climate Control Standards Committee. Exposure concentrations and durations were estimated and compared with toxicity data for refrigerants currently used in automotive air conditioners. Uncertainty was high for the estimated numbers of exposures, exposure concentrations, and exposure durations. Uncertainty could be reduced in the future by conducting more extensive surveys, measurements of refrigerant concentrations, and exposure monitoring. Nevertheless, the analysis indicated that the risk of exposure of service technicians and vehicle occupants is significant, and it is recommended that no refrigerant that is substantially more toxic than currently available substitutes be accepted for use in vehicle air-conditioning systems, absent a means of mitigating exposure.

Air Conditioning↗
PubMed2005

The air-conditioning capacity of the human nose.

The nose is the front line defender of the respiratory system. Unsteady simulations in three-dimensional models have been developed to study transport patterns in the human nose and its overall air-conditioning capacity. The results suggested that the healthy nose can efficiently provide about 90% of the heat and the water fluxes required to condition the ambient inspired air to near alveolar conditions in a variety of environmental conditions and independent of variations in internal structural components. The anatomical replica of the human nose showed the best performance and was able to provide 92% of the heating and 96% of the moisture needed to condition the inspired air to alveolar conditions. A detailed analysis explored the relative contribution of endonasal structural components to the air-conditioning process. During a moderate breathing effort, about 11% reduction in the efficacy of nasal air-conditioning capacity was observed.

Air↗
PubMed1963

Bacteriology of air-conditioning ducts with special reference to operating rooms.

The number of bacteria in air, before filtration with five different easily available filters in the low positive-pressure type of airconditioning system of the Winnipeg General Hospital, was between 3 and 4/cu. ft., and after filtration between 1 and 2/cu. ft. with all types of filters. Cl. welchii contributed about 1% and Staph. pyogenes about 0.1% of this total. Sampling the exhaust air from an operating room during an operation showed that the bacterial count fluctuated with the degree of activity in the room and was from two to 10 times as high as in the air delivered to the room.Atlhough every reasonable attempt should be made to diminish the bacterial count of air in hospitals, if much energy and money is to be spent it would probably be wiser to investigate sources of hospital infection other than the type of air-conditioning system described in this report.

Air Conditioning↗
PubMed2004

An effective silencer design for artificially air conditioned environment.

An effective silencer for an air conditioning duct is studied. A duct with an acoustically soft boundary is employed as an effective silencer. On the acoustically soft boundary the sound pressure is zero and it is impossible to realize such boundary in the air-borne sound field, because of the non-existence of a much lighter medium than the air. In this study, the arrangement of one-quarter wave-length acoustic tubes is employed as a soft boundary. This acoustic tube has frequency dependence, but the sound pressure becomes nearly zero at the tube mouth around the odd resonance frequency. The relation between the noise reduction efficiency and this acoustically soft boundary is examined experimentally and more than 40 dB noise reduction is obtained in a one-half octave band around the first resonance frequency. It is also made clear that more than one wave length of soft boundary is required to get enough reduction compared with the reduction obtained in the case of quite a long soft boundary.

Air Conditioning↗
PubMed1996

[The effect of anesthetic method on enflurane air pollution in non-air conditioned operating rooms].

UNLABELLED: Pollution of work areas by volatile anaesthetics and nitrous oxide occurs during general anaesthesia. Short anaesthesia procedures are often carried out in operating theatres that are not equipped with air-conditioning systems. Methods of lowering exposure during short procedures, where mask anaesthesia is the usual procedure, are double masks and the laryngeal mask. The aim of our investigation was to determine the possibility of lowering the pollution of the environment to below national and international thresholds in a non-air-conditioned work area and to find out which method of anaesthesia is the most effective in environmental protection, i.e. which has the lowest leakage rate. METHODS: In our investigation, at two points of the work area the mean enflurane [2-chloro-1-(difluor-omethoxy)-1,1,2-trifluoro-ethane] concentrations were measured under daily routine conditions in a non-ventilated anaesthesiological work area by a gas chromatography. Anaesthesia with single masks, double masks, laryngeal masks or endotracheal intubation was carried out. RESULTS: No differences were found in the mean concentration of enflurane during the anaesthesia procedures. The leakage rates of endotracheal intubation anaesthesia were the lowest. DISCUSSION: In unventilated work areas, it was not possible to lower the exposure of the personnel by changing the method of anaesthesia. The application of procedures like double or laryngeal masks does not avoid the need for installation of air-conditioning systems in all work areas were anaesthesia is performed.

Air Conditioning↗
PubMed1990

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

Blood pressure and pulse of 32 young healthy Nigerian volunteers were determined after they had been in an air-conditioned room from between 60 and 90 minutes. The same determinations were made at the same time of another day with air-conditioning switched off for the same period. The mean systolic blood pressure (SBP) was 115.3 +/- 11.5 mmHg under air-conditioner (AC) and 108.5 +/- 10.1 mmHg without air-conditioning. This difference was statistically significant (p less than 001). Similarly, diastolic blood pressure (DBP) was higher in AC, 69.4 +/- 8.9 mmHg, than without AC, 66.5 +/- 9.1 mmHg (p less than 025), while mean blood pressure was also higher in AC, 84.9 +/- 9.1 mmHg, than without, 79.9 +/- 7.7 mmHg (less than 005). There was no significant different in pulse rate. These differences in the BP of normal young subjects are not thought to be of clinical significance but the result suggests that study of the effect of AC on BP and pulse in older subjects and hypertensive subjects is desirable.

Adult↗
PubMed2001

Prevalence of smokers among air-conditioned coaches, Pakistan.

OBJECTIVE: To estimate the proportion of smokers among passengers of air-conditioned (A/C) coaches running between Karachi and Hyderabad. Pakistan. METHOD: A cross-sectional survey was done on passengers and staff members of 20 air-conditioned coaches. RESULTS: Of 847 passengers interviewed, 17.3% were smokers and 11.7% passengers smoked during travel while rest of them remained passive smokers. Out of 147 smokers 91.2% were literate persons. Among staff members 59.3% were smokers. Approximately 56% of smokers among passengers were in the age range of 14-40 years. In 95% of A/C coaches there were no anti-smoking warning signs or written words present. CONCLUSION: In this study majority of smokers were literate, so inter-personal communication and counseling may change the smoking behavior. Ministry of Health should disseminate educational messages regarding hazards of passive smoking among commuters of AC coaches and above all proper implementation of legislation for smoking at public places especially in transport.

Adolescent↗
PubMed2005

Influence of mobile air-conditioning on vehicle emissions and fuel consumption: a model approach for modern gasoline cars used in Europe.

The influence of air-conditioning activity on the emissions and fuel consumption of passenger cars is an important issue, since fleet penetration and use of these systems have reached a high level. Apart from the MOBILE6 study in the United States, little data is available on the impact of air-conditioning devices (A/Cs). Since weather conditions and A/C technologies both differ from those in the U. S., a test series was designed for the European setting. A fleet of six modern gasoline passenger cars was tested in different weather conditions. Separate test series were carried out for the initial cooldown and for the stationary situation of keeping the interior of the vehicle cool. As assumed, CO2 emissions and fuel consumption rise with the thermal load. This also causes a notable rise in CO and hydrocarbons (HCs). Moreover, A/Cs do not stop automatically at low ambient temperatures; if necessary, they produce dry air to demist the windscreen. A model is proposed that shows a constant load for lower temperatures and a linear trend for higher temperatures. The initial cooldown tests highlight significant differences among cars but show that A/C operation for the initial cooling of an overheated passenger compartment does not result in any extra emissions for the fleet as a whole.

Air Conditioning↗
PubMedDate not supplied

High prevalence of sick building syndrome in a new air-conditioned building in Italy.

This study, which was conducted in central Italy, included (a) 525 office workers employed in an air-conditioned building that had fan coil units in every room (building B) and (b) 281 subjects who worked in three naturally ventilated buildings (building A) that were operated by the same public administration. The prevalence of work-related symptoms was assessed by a questionnaire that was administered by an occupational medicine specialist. The most frequent complaints of employees in building B were dry air, strong lighting, and high temperature. Employees who worked in this building experienced a statistically higher prevalence of symptoms that were characteristic of the sick building syndrome. This is the first time that this syndrome has been reported in Italy. Excessive illumination, a low relative humidity, and fiberglass on floors and furniture might have contributed to the symptoms. Inadequate maintenance of the building's air-conditioning plant and the employees' lack of information regarding self-regulation of the fan coil units may also have contributed to the prevalence of symptoms.

Air Conditioning↗
PubMed1997

Performance of noise indices in air-conditioned landscaped office buildings.

Noise measurements and a questionnaire survey were carried out in air-conditioned landscaped offices in the present study in an attempt to find out what existing noise index gives the best correlation with the auditory sensation feeling of office workers. Results from statistical analyses show that the Equivalent Sound Pressure LEvel is the best among the 14 commonly used noise indices for this purpose. It is also found that the less commonly used Zwicker's loudness level performs better than the commonly adopted Noise Criterion curves and Noise Rating curves in predicting auditory sensation of office workers in air-conditioned landscaped offices. The performance of the 14 noise indices in predicting auditory comfort are compared.

Air Conditioning↗
PubMed2005

Air conditioning closely examined.

The intricacies of the provision and control of air conditioning in hospitals have been debated for decades. For this Health Estate Journal 'Then and now' feature, Mike Arrowsmith BSc (Hons) CEng FIMechE FIHEEM, technical editor, provides commentary on an article which was published in The Hospital Engineer, the journal of the Institution of Hospital Engineers, in July 1960. The text of this article, which was based on a paper read before the Glasgow Branch of the Institution, follows that of the commentary.

Air Conditioning↗
PubMed1993

Effect of heating-ventilation-air conditioning system sanitation on airborne fungal populations in residential environments.

Commercial air duct sanitation services are advertised to the public as being effective in reducing indoor aeroallergen levels despite the absence of published supporting data. Eight residential heat-ventilation-air conditioning (HVAC) systems in six homes and seven HVAC systems in five homes in winter and summer, respectively, were sampled to determine fungal colony forming units (CFUs) prior to and after an HVAC sanitation procedure was performed by a local company. Two houses in which no sanitation procedure was performed served as controls in each study phase. Two sample sets were obtained at each HVAC system prior to cleaning in order to determine baseline CFU levels. The test HVAC systems were then cleaned, and the HVAC systems allowed to operate as desired by the residents. Posttreatment sampling was performed 48 hours and then weekly after cleaning for 8 weeks. The HVAC systems were analyzed by exposing sterile 2% malt extract media plates at a 90-degree angle to the air flow at the air supply and air return vents. The baseline CFUs were similar in the control and study houses. Eight weeks after sanitation, the study houses demonstrated an overall CFU reduction of 92% during winter and 84% during summer. No reduction in CFU values was observed over the 8-week study period for the houses selected as controls. Further, HVAC sanitation appeared to reduce the number of fungal colonies entering and leaving the HVAC system, suggesting that the HVAC contained a significant percentage of the total fungal load in these homes. These data suggest that HVAC sanitation may be an effective tool in reducing airborne fungal populations in residential environments.

Air Conditioning↗
PubMed1993

Design considerations for heating, air conditioning, and exhaust systems in critical care units.

Air quality, temperature control, and air movement directly affect infection control, comfort, and safety in critical care units. This article explains basic concepts in the heating, ventilation, and air conditioning that affect patient care. Functional requirements must be determined early in the design process and discussed with clinicians, engineers, and architects to assure understanding and correct design.

Air Conditioning↗