Germicidal ultraviolet irradiation in air conditioning systems: effect on office worker health and wellbeing: a pilot study.

OBJECTIVES: The indoor environment of modern office buildings represents a new ecosystem that has been created totally by humans. Bacteria and fungi may contaminate this indoor environment, including the ventilation systems themselves, which in turn may result in adverse health effects. The objectives of this study were to test whether installation and operation of germicidal ultraviolet (GUV) lights in central ventilation systems would be feasible, without adverse effects, undetected by building occupants, and effective in eliminating microbial contamination. METHODS: GUV lights were installed in the ventilation systems serving three floors of an office building, and were turned on and off during a total of four alternating 3 week blocks. Workers reported their environmental satisfaction, symptoms, as well as sickness absence, without knowledge of whether GUV lights were on or off. The indoor environment was measured in detail including airborne and surface bacteria and fungi. RESULTS: Airborne bacteria and fungi were not significantly different whether GUV lights were on or off, but were virtually eliminated from the surfaces of the ventilation system after 3 weeks of operation of GUV light. Of the other environmental variables measured, only total airborne particulates were significantly different under the two experimental conditions--higher with GUV lights on than off. Of 113 eligible workers, 104 (87%) participated; their environmental satisfaction ratings were not different whether GUV lights were on or off. Headache, difficulty concentrating, and eye irritation occurred less often with GUV lights on whereas skin rash or irritation was more common. Overall, the average number of work related symptoms reported was 1.1 with GUV lights off compared with 0.9 with GUV lights on. CONCLUSION: Installation and operation of GUV lights in central heating, ventilation and air conditioning systems of office buildings is feasible, cannot be detected by workers, and does not seem to result in any adverse effects.

Aeroallergens and work-related respiratory symptoms among office workers.

OBJECTIVE: We sought to determine the association between office workers' respiratory tract symptoms and immediate skin test reactions with exposure to fungal and house dust mite aeroallergens at their work sites. METHODS: An initial prevalence survey was conducted among 1102 full-time workers in six mechanically ventilated, air-conditioned, nonindustrial buildings in downtown Montreal. Detailed environmental measures of 214 subjects' work sites were determined. Half of the workers reported frequent work-related respiratory tract symptoms on the initial survey. Participants simultaneously underwent allergy skin prick testing and completed a second self-administered questionnaire. RESULTS: Contaminant levels were low and not associated with symptoms in the great majority of workers. For approximately 17% of workers, symptoms were associated with exposure to total concentrations of house dust mite allergen greater than 1 microg/gm floor dust (odds ratio [OR], 5.0; 95% confidence interval [CI], 1.3, 19.5]) or to detectable airborne Alternaria allergens in their offices (OR, 3.3; 95% CI, 1.2, 9.4 and in the ventilation system supplying their offices (OR, 3.9; 95% CI, 1.6, 9.6). Workers with positive skin test reactions to Alternaria extract were exposed at their work site to airborne Alternaria allergen (OR, 4.4; 95% CI, 1.4, 14.5) and cited significantly more respiratory symptoms on both questionnaires. Detection of airborne Alternaria allergen at work sites was significantly associated with detection in the ventilation system (OR, 4.0; 95% CI, 1.4,10.9); this was in turn associated with lower efficiency filters. CONCLUSIONS: Potentially avoidable exposure to aeroallergens accounted for symptoms in a small subgroup of office workers with frequent work-related respiratory tract symptoms.

Effect of a new ventilation system on health and well-being of office workers.

Sick building syndrome is the term given to a heterogeneous constellation of symptoms that affects workers in modern mechanically ventilated office buildings. Although the cause is unknown, there is evidence that the local environment of the work station is an important determinant of symptoms. In this study, investigators examined the effect of a new, individually controlled ventilation system on workers' symptoms. Investigators studied two groups of workers in one mechanically ventilated office building: (1) a control group at whose worksite no intervention was made and (2) an intervention group. The intervention consisted of installation of a device that allowed each worker control over the ventilation supplied to his or her worksite. Just before, and 4 and 16 mo after installation of this device, workers completed self-administered questionnaires regarding occurrence of symptoms. The new ventilation system resulted in higher air velocities, more variable temperatures, and higher concentrations of airborne dust and fungal spores. Four months after installation, workers with the new ventilation system reported fewer symptoms that were (a) work-related (p < .05) and that were work-related and frequent (p < .05); in addition, they reported fewer symptoms that reduced their capacity to work (p < .01). Sixteen months after installation, workers with the new device reported fewer symptoms than at baseline (although not as significantly), and they indicated that the indoor air quality improved their productivity by 11%, compared with a 4% reduction of productivity among the control group of workers (p < .001). Investigators concluded that the new ventilation system, which provided the workers with individual control over ventilation, was associated with important and sustained reduction in symptoms.

Tuberculosis infection among health care workers in Montreal.

We conducted a cross-sectional survey to estimate the prevalence of tuberculosis infection among health care workers at two downtown Montreal hospitals. Participants completed questionnaires, then underwent two-step tuberculin testing. Records of previous tuberculin tests and BCG vaccinations were reviewed. Charts of all tuberculosis patients admitted in 1992-93 were also reviewed. Air changes and direction of air flow in patient care areas were measured using tracer gas techniques and smoke tubes. Of 619 eligible workers, 522 participated (84%). 196 (38%) were tuberculin reactors; 23 (4%) had documented conversions. Inadequate ventilation and delays in diagnosis were identified at both hospitals. Comparing clinical with nonclinical personnel, the adjusted odds of a significant initial tuberculin reaction were 2.6 (95% confidence interval 1.3, 5.2), of a documented conversion 13.6 (1.4, 132), and of a booster reaction 0.9 (0.2, 3.6). Initial tuberculin reactivity was associated with male gender (p = 0.008), BCG vaccination (p = 0.0001), foreign birth (p = 0.007), age (p < 0.0001), and occupation (p = 0.02); conversion with male gender (p = 0.001) and occupation (p = 0.01); and boosting with older age (p = 0.02) and BCG vaccination (p = 0.001). Among clinical personnel at two hospitals, the prevalence of significant tuberculin reactions and of documented conversions was unexpectedly high.

Measuring ventilation of patient care areas in hospitals. Description of a new protocol.

It has been recommended that ventilation of health care facilities should be monitored regularly to reduce the risk of nosocomial transmission of tuberculosis. We developed a simple method to measure air-change rates and direction of airflow in patient care areas. Pure carbon dioxide (CO2) was released at 13.5 L/min for 5 min, then measured for 30 min within the room and outside in the hallway. Smoke tubes were also used to measure direction of airflow. Doors and windows (if openable) were manipulated. This protocol, when conducted in five offices in 30 patients care areas in two hospitals, provided good mixing and reproducible decay curves, with less than 15% coefficient of variation for repeated measures over a wide range of air-change rates. Manipulation of door and/or window produced significant changes in air-change rates and airflow direction, although calculated air-change rates were more variable. Smoke tube measurements were inconsistent, agreed poorly with evidence of CO2 movement from room to hall, and were strongly affected by room to hallway temperature differentials. CO2 release and measurement proved to be a simple, yet reliable, method to measure air-change rates and the effect of door or window manipulation. Smoke tube measurements were not reliable to characterize direction of airflow.

[The use of a somatostatin analog (Sandostatin) in percutaneous drainage of pancreatic pseudocysts]. / Somatostatin analog (Sandostatin) alkalmazása pancreas pseudocysták percutan katéteres kezelésében.

The inflammatory pancreatic diseases are usually hardly governable; special problems are arosen with the treatment of pancreatic fluid collections. The focal pericystic pancreatitis, the reactive inflammation developing in the course of the injury of the gland as well as draining pancreatic duct filling the cyst up may result in pitfalls. Thus subcutaneous administration of Sandostatin was added to the usual therapeutic regimen in 12 patients. It was applied with external and internal drainage of pseudocysts in 10 patients and in one of them the complication was reduced in an unsuccessful attempt, respectively. The pseudocyst of one patient disappeared by sole somatostatin administration. One cystic formation did not respond to this kind of treatment thus a drainage procedure had to be performed. Based on our initial experiences we seem to find a rather promising tool that may influence the basic process beneficially and makes our instrumental interventions safer and more successful.

[Bilateral neonatal adrenal hemorrhage associated with hypoadrenalism]. / Hypadreniával járó újszülöttkori, kétoldali mellékvesevérzés.

A newborn is described, who was born in term with 3250 g weight, after intrauterine hypoxia. She was born with vacuum extraction, and suffered from birth trauma and intrauterine infection. At age of one day manifested an eclampsia, which was hardly diminishable. The serum Na level was 118 mmol/l. Bilateral adrenal apoplexy was visible with ultrasound. The newborn was treated with infusion of sodium chloride and glucose, with antibiotic and glucocorticoid hormone. Her condition improved rapidly. Her serum cortisol level at 8 and 15 day after stopping of 12 days prednisolon therapy was below 2.5 micrograms/dl, marking hypadrenia. At age 3 months the function of adrenals was normal: the serum cortisol level was 11.4 micrograms/dl, and after ACTH stimulation it run up to 44.5 micrograms/dl. By screening of 1491 newborns, 13 adrenal apoplexy was found. The other 12 were one-sided and symptomless.

[Gluing of sterile abdominal benign cyst walls with tissue adhesives (Tissucol) (preliminary report)]. / Steril, benignus hasi folyadékgyülemek falainak összeragasztása szöveti ragasztóval (tissucol) (elözetes közlemény).

The authors, endeavouring to stick the walls of percutaneously emptied cysts together had applied the two-component Tissucol fibrin glue in the treatment of abdominal and thoracic cysts. Their ten cases, however, may be considered only as preliminary experiences. It seems that the method can be recommended for an attempt to cease these formations in a fast and simple way. Nevertheless, this method must not be the subject of treatment in infected and malignant fluid collections, but seems successful in pancreatic pseudocysts, in spite of their higher proteolytic activity.

[Ultrasound-guided percutaneous external catheterization-drainage of pancreas-related fluid collections]. / Pancreas eredetü folyadékgyülemek ultrahanggal vezérelt perkután külsö katéterezése (intracavitalis beavatkozások).

The authors have extended the diagnostics indispensable in drainage of pancreatic fluid collections by intracavitary invasive methods. In five patients exfoliative cytology, in to patients target biopsy and in other two septotomy were performed. Intracavitary invasive diagnostic and therapeutic methods may be useful complementary tools with the traditional technique. They can easily and effectively be carried out without complications if their utilization is well indicated. They may increase diagnostic accuracy and decrease discomfort of the patient in therapy.

[Visible venous bloodflow in real-time abdominal sonography, possibly a sign of hepatitis B virus-induced, compensated immune hemolysis]. / Real-time hasi ultrahang vizsgálat során látható vénás vérkeringés, amely B-hepatitis vírus által indukált, kompenzált immun-haemolysis sonographiás jele lehet.

In 15 patients examined for the suspicion of hepatobiliary disease the venous blood flow was visible by the permanent circulation of soft particles in both the systemic and the portal veins with abdominal real-time ultrasonography. In order to clarify the background of the phenomenon there were extended laboratory examinations carried out. In the course of them the infectedness of the patients with Hepatitis-B virus, immune haemolysis and the disorder of the cellular immunity could be demonstrated. Similar visual phenomenon was found only in one patient suffering only from immune haemolysis, but no hepatic disease. The hepatic patients generally do not show the phenomenon. On the basis of these it is presumed that visible venous flow in real-time abdominal ultrasonography may be a sign of compensated immune haemolysis induced by Hepatitis-B virus infection.

[Ultrasound-guided percutaneous antegrade wirsungography in chronic calcifying pancreatitis]. / Ultrahanggal vezérelt percutan antegrad wirsungographia idült kalcifikáló pancreatitisben.

Dilated pancreatic duct was found by ultrasonography in a patient in association with the characteristic sonographic features of chronic calcifying pancreatitis. Endoscopic retrograde pancreatography showed an obstruction of the Wirsung's duct 3 cm far from the papilla of Vater. Further parts of the duct could not be opacified by this manner. However, visualisation of the rest of the pancreatic duct was successfully performed by ultrasonically guided antegrade wirsungography making the preoperative planning of the suitable type of surgery possible. Beside the case history the importance of the is method is also discussed in diagnosis of pancreatic diseases.