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Biomedical subjects

J Boe

Publications and source records attributed to J Boe.

At least 37 records · Page 2Linked to original sources
PubMed1998

Do patients using long-term liquid oxygen differ from those on traditional treatment with oxygen concentrators and/or compressed gas cylinders? A comparison of two national registers.

Long-term oxygen therapy (LTOT) in patients with chronic hypoxaemia is an expanding field. Traditional stationary oxygen, with and without portable compressed gas cylinders, and portable liquid oxygen equipment is available today. No official guidelines exist for the prescription of liquid oxygen vs traditional oxygen supply in LTOT, although it is generally though that patients receiving liquid oxygen are younger and less seriously affected. The authors tested this hypothesis by comparing register data from two national Scandinavian registers of patients on LTOT in the same time period; one including all the patients on traditional oxygen treatment alone, e.g. concentrators and compressed gas cylinders (n = 1039), the other including all the patients using portable liquid oxygen alone (n = 117). About 80% of the patients in both groups suffered from chrome obstructive pulmonary disease. Younger patients were found in the liquid oxygen group (P < 0.004), but with clinically slightly worse blood gas derangement (mostly statistically significant). They had higher frequency of previous or present oedema (P < 0.0001), and there were more smokers in this group (P < 0.0001). No significant differences were seen with respect to sex distribution or oxygen delivery systems. Higher oxygen dose and longer daily oxygen treatment (P < 0.0001) were prescribed for the liquid oxygen patients compared with the patients on traditional oxygen with statistically higher oxygen tension during the prescribed treatment. A slight further increase in PaCO2 was seen in both groups during oxygen treatment, of doubtful significance. Compared with patients on traditional oxygen, liquid oxygen thus appears to be prescribed for younger patients, independent of clinical status or blood gas levels.

Age Distribution↗
PubMed1998

Beta 2-agonists administered by a dry powder inhaler can be used in acute asthma.

Patients with acute asthma attending the emergency room were included in a double-blind, double-dummy and parallel group study to investigate whether a dry powder inhaler (Turbuhaler) can be used in acute asthma. If so, the aim was to establish the potency relationship between a beta 2-agonist (salbutamol) administered by the dry powder inhaler and the pressurized metered-dose inhaler (pMDI). Eighty-six patients with a mean age of 38 years and forced expiratory volume in 1 s (FEV1) of 37% of predicted normal value were randomized at Siriraj Hospital in Bangkok to either Turbuhaler (50 micrograms dose -1) or pMDI (100 micrograms dose -1) with spacer (Volumatic). Doses of 100 + 300 + 300 + 300 micrograms salbutamol were given at 0, 15, 30 and 45 min via Turbuhaler and repeated at 90, 105, 120 and 135 min (total dose 2000 micrograms). The same inhalation schedule with identical number of doses was used for the pMDI with spacer but in double doses (total 4000 micrograms), assuming a dose-potency ratio of salbutamol administered via Turbuhaler compared with the pMDI of 2:1. At 85 min after the first dose, 60 mg prednisolone was given orally. FEV1 was measured 10 min after each dosing. Peak inspiratory flow (PIF) through Turbuhaler was measured on each dosing occasion. Plasma (P)-salbutamol, serum (S)-potassium concentrations, pulse rate, blood pressure and adverse events were recorded. No statistically significant differences were observed in the increase in FEV1 between the groups: 55 min (165 min) after the first dose, the increase was 0.47 l and 47% (0.64 l and 63%) in the Turbuhaler group, and 0.46 l and 42% (0.68 l and 65%) in the pMDI group. Mean PIF though Turbuhaler was 49 l min -1 (range 26-68) at first inhalation and increased to 60 l min -1 (range 38-86). There was no correlation between the initial PIF through Turbuhaler and the initial FEV1 response. P-salbutamol and S-potassium values correlated well. A larger decrease in S-potassium was noticed after 75 min in the pMDI group (0.38 mmol l -1) compared with the Turbuhaler group (0.23 mmol l -1) (P = 0.02). In conclusion, the use of a dry powder inhaler, Turbuhaler, was investigated in the emergency room treatment of acute asthma, and was as effective as a pMDI with spacer. Half the dose of salbutamol administered via Turbuhaler was as effective as the full dose given via a pMDI with spacer.

Acute Disease↗
PubMed1998

Bronchoscopy with transbronchial biopsies: measurement of bleeding volume and evaluation of the predictive value of coagulation tests.

The objectives of this study were to measure the bleeding volume associated with fibreoptic bronchoscopy with transbronchial biopsies (TBB), to correlate it with coagulation tests and to compare bleeding volume in patients with and without lung transplant. A total of 104 consecutive TBB in 51 different patients was evaluated prospectively. Before each procedure, haemoglobin, blood platelets, prothrombin time (PT), activated partial thromboplastin time (aPTT) and bleeding time were measured. During the procedure, lavage fluid and blood were collected by suction. The haemoglobin concentration of the mixture was measured and bleeding volume was calculated. Clinically significant bleeding was arbitrarily defined as >20 mL blood present in lavage fluid. The mean+/-SD bleeding volume was 7+/-10 mL with no statistically significant difference between transplanted and nontransplanted patients. In eight procedures (7.7%) the bleeding volume was >20 mL (range 22-61 mL). Prebiopsy values for blood platelet counts, PT and aPTT did not predict a bleeding tendency in any of the procedures in which significant bleeding occurred. No correlation was found between bleeding time and bleeding volume in the 17 procedures performed in patients with a prolonged bleeding time (> or =10 min). The bleeding associated with transbronchial biopsies was usually minor and quantitatively similar in patients with or without lung transplant. Coagulation tests could not predict clinically significant bleeding, which may occur in patients with normal coagulation test results.

Adult↗
PubMed1998

High-dose inhaled budesonide may substitute for oral therapy after an acute asthma attack.

Patients attending the emergency room with acute asthma, participating in a study comparing salbutamol (albuterol in the United States) via a dry powder inhaler (Turbuhaler) with pressurized metered-dose inhaler (pMDI), were included in this 1-week follow-up study with the aim of assessing whether inhaled budesonide via Turbuhaler may be an alternative to prednisolone tablets after an acute asthma attack. Eighty-one patients with a mean age of 38 years and forced expiratory volume in 1 sec (FEV1) of 64% predicted normal value after treatment with salbutamol were randomized in this double-blind, double-dummy, parallel-group study. The doses given were budesonide 1600 microg b.i.d. or prednisolone in daily doses from 40 mg (day 1) decreased to 5 mg (day 7). FEV1 was recorded before and after the 7-day treatments and peak expiratory flow (PEF) morning and evening, clinical symptoms (visual analogue scale 0-100), and doses of rescue medication (terbutaline Turbuhaler 0.25 mg/dose) were recorded daily. The mean increase in FEV1 from baseline to day 7 was 17.3% in the budesonide Turbuhaler group and 17.6% in the prednisolone group. Mean values of morning PEF increased from day 1 to day 7 by 67 L/min in the budesonide Turbuhaler group and by 57 L/min in the prednisolone group (not significant). There were no statistically significant differences between the groups in clinical symptoms and in the number of doses of rescue medication. Because of disease deterioration, five patients in the Turbuhaler group and three in the prednisolone group needed additional symptomatic as well as corticosteroid treatment. Inhaled budesonide in high doses may be a substitute for oral therapy as follow-up treatment after an acute asthma attack.

Acute Disease↗
PubMed1997

A test chamber for experimental hydrogen fluoride exposure in humans.

An inhalation chamber was built to perform experimental studies with hydrogen fluoride (HF), other gases, and particulate matter. The present study sought to describe a new gas delivery system and the distribution and concentration of HF gas in the chamber. The aluminum chamber has a volume of 19.2 m3 and a variable ventilation rate of about 1 to 10 air changes per hour. The negative pressure difference between the chamber and outside air can be regulated from 0 to 300 Pa. HF was fed at concentrations of up to 4000 mg/m3 directly into the ventilation duct feeding the chamber through openings with diameters as small as 50 microns, oriented opposite to the airflow. Gas flow was varied from about 0.1 dm3/min at a pressure of 4 atm. The dilution factor of HF concentration from cylinder to chamber was on the order of 10(3) to 10(4). The standard deviation (SD) of the HF concentrations at a fixed measurement point during a 1-hour test was typically 0.05 mg/m3 at a time-weighted average (TWA) concentration of 2.66 mg/m3. The SD of the TWA HF concentrations at six locations in the chamber was typically 0.05 mg/m3 and 0.29 mg/m3 at 0.61 and 3.46 mg/m3, respectively. Human exposure could be predicted from calculations based on ventilation data, gas flow, and observed ratio between calculated and measured concentrations. When the target exposure concentration was 1.5 mg/m3, the measured mean exposure concentration was typically 1.54 mg/m3 (range: 1.4-1.7 mg/m3, SD 0.09 mg/m3, n = 8). The chamber is well-suited for inhalation studies in humans. Chamber atmosphere was controlled and has proved to be stable and homogeneous, even in tests with HF, a highly reactive gas in the class of superacids.

Air Pollutants↗
PubMed1997

Relation between decline in FEV1 and exposure to dust and tobacco smoke in aluminium potroom workers.

OBJECTIVES: To investigate the relation between pulmonary function and occupational exposure in aluminium pot operators. METHODS: 2795 observations were obtained in 630 workers over six years of follow up. An autoregressive method of analysis was used. RESULTS: After adjustment for FEV1 in the three previous years, the effect of smoking v no smoking on FEV1 was -43.1 ml, 95% confidence interval (95% CI) -72.3 to -13.9. Similarly, an increase in the exposure to particulates by 1 mg/m3 corresponded to a decrease in FEV1 of -11.9 ml, 95% CI -19.9 to -3.9. Age was a significant predictor of both FEV1 and FVC. CONCLUSION: Exposure to particulates in aluminium potrooms seems to increase the decline in FEV15 thereby increasing the risk of development of chronic obstructive lung disease in pot operators.

Adolescent↗
PubMed1997

Exposure to hydrogen fluoride: an experimental study in humans of concentrations of fluoride in plasma, symptoms, and lung function.

OBJECTIVES: To study the absorption of inhaled hydrogen fluoride (HF) by measuring plasma fluorides and HF concentrations in the breathing zone during exposure to HF. A possible dose-effect relation was investigated by following airway symptoms and lung function-that is, forced expiratory volume in one second (FEV1) and forced vital capacity (FVC)-during and after exposure to HF. METHODS: 20 healthy, male volunteers were exposed for one hour to constant HF concentrations that ranged from 0.2 to 5.2 mg/m3; these concentrations are known to occur among potroom workers in the primary aluminium industry. Plasma fluorides were analysed before, during, and after exposure. Symptoms from the eyes and the upper and lower airways were registered and graded from 1 to 5 with a standardised questionnaire. RESULTS: The total symptom score was significantly increased at the end of exposure for all the subjects as a group (P < 0.01) and for the group exposed to HF below the present Norwegian standard for total fluorides 0.6 mg/m3 (P = 0.05). No change was detected in FEV15 although a significant decrease was found in FVC in the group exposed to fluorides below the hygienic standard (n = 9) and for the entire group (n = 23). Almost all the symptoms had disappeared four hours after the end of exposure. Symptom scores from the upper airways were significantly correlated with the HF concentration (r = 0.62, P = 0.002), the change in plasma fluoride concentration (delta C) (r = 0.51, P = 0.01), and the maximum plasma fluoride concentration (Cmax) (r = 0.42, P = 0.05). A significant correlation was also found between the total symptom score for airways and the HF concentration. CONCLUSIONS: The present study showed a strong relation between inhaled HF and concentrations of fluoride in plasma. Upper airway and eye symptoms occurred after one hour of exposure to HF even when below the Norwegian hygienic standard for fluorides.

Administration, Inhalation↗
PubMed1996

Single lung transplantation for chronic obstructive pulmonary disease: pulmonary function and impact of bronchiolitis obliterans syndrome.

Chronic obstructive pulmonary disease (COPD) is now the most common indication for single lung transplantation. In long-term follow-up, obliterative bronchiolitis is a major problem. The aim of the present study was to perform a long-term follow-up of the pulmonary function and to examine the effect of development of bronchiolitis obliterans syndrome (BOS). Nineteen patients with end-stage COPD underwent single lung transplantation and were followed regularly with pulmonary function tests, and ventilation and perfusion scintigraphy (mean observation time 29 months). They were divided into two categories, with and without BOS, using the definition recommended by the International Society for Heart and Lung Transplantation working group. A mixed model analysis of variance with BOS as co-variate was used to evaluate its effect on pulmonary function. Spirometry, lung transfer factor for carbon monoxide (TLCO), arterial blood gases and 6-min walk test improved significantly (P < 0.001) from before transplantation to 3 months after transplantation. Nine patients developed BOS. Implied by the definition of the syndrome, forced expiratory volume in 1 s (FEV1) was significantly (P < 0.001) lower for patients with BOS while there was no significant effect of BOS category on TLCO corrected for alveolar volume (VA) or perfusion to transplant. Patients without BOS maintained their pulmonary function, and ventilation and perfusion to transplant for more than 3 yr after transplantation. The present results suggest that decreasing FEV1 accompanied by an unchanged TLCO/VA and pulmonary perfusion support the diagnosis of BOS after single lung transplantation for COPD.

Adult↗
PubMed1996

Deaths from active tuberculosis: can we rely on notification and mortality figures?

SETTING: Notification rates and mortality are the main indicators in the epidemiology of tuberculosis. While errors in case notification are known to be considerable, the quality of the data on deaths is largely unknown. OBJECTIVE: To validate the quality of data on deaths from active tuberculosis. DESIGN: We compared deaths from active tuberculosis in Statistics Norway with the National Tuberculosis Register (NTR) and cases found by autopsy in two Norwegian counties in 1977-1989. We also assessed the diagnostic classification and inclusion criteria for tuberculosis. RESULTS: 110 patients were entered into the study. We excluded 30 of 106 patients in Statistics Norway, primarily because of inactive tuberculosis (16) or minimal lesions (7). We found an additional 20 patients in the NTR and 14 more from autopsy reports. These missing cases were registered in Statistics Norway with a different diagnosis (28), inactive tuberculosis (4) or not found (2). Nineteen of them were diagnosed with tuberculosis by autopsy and five by cultures reported after death. We altered the diagnostic classification of underlying cause in 14% and found tuberculosis to be the underlying cause in 65 patients. CONCLUSION: The mortality rate from active tuberculosis in Statistics Norway was fairly correct, but one-third were under-reported and one-third over-reported. The mortality rate includes only half of all the deaths from active tuberculosis. All the cases in which active tuberculosis is mentioned on the death certificate are a clearer indication of tuberculosis deaths.

Autopsy↗
PubMed1996

Cardiopulmonary sequelae after treatment for Hodgkin's disease: increased risk in females?

BACKGROUND: The treatment of Hodgkin's disease (HD) involves irradiation and chemotherapy. Both modalities may cause heart and lung injury. We aimed to assess 1) the occurrence of such injury, 2) the extent to which combined versus single-organ-affection resulted in disability, and 3) whether determinants for cardiopulmonary injury could be identified. PATIENTS AND METHODS: A national cohort (n = 116) of HD patients (mean age 37 +/- 7 (SD) years, 67 males) was examined by interview, echocardiography, bicycle exercise test and lung function tests, 5-13 years after mediastinal irradiation with or without chemotherapy. RESULTS: Cardiac, pulmonary or combined sequelae occurred, respectively, in 21%, 15% and 19% of the patients affecting 75% of the females versus 41% of the males (P < 0.001). Of the patients with combined sequelae, 27% were disabled versus 4% of the rest (P < 0.05). Combined sequelae was associated with dyspnoea (P < 0.001) and reduced maximal exercise heart rate (P < 0.05). Compared to males, females had an increased risk of heart valve regurgitation (46% versus 16%, P < 0.001), pericardial thickening (22% versus 10%, P = 0.07) and reduced gas transfer (41% versus 22%, P = 0.03). Female gender was a significant risk factor for cardiac and/or pulmonary sequelae (OR 6.1, 95% CI 2.4-15.7), whereas age, follow-up period, smoking habits, histology, bulky mediastinal disease, radiation dose and chemotherapy were not. Mean exercise work capacity and O2-saturation were within normal limits. CONCLUSIONS: Although cardiac and/or pulmonary sequelae were detected in more than half of the patients, only combined injury was associated with disability, dyspnoea and reduced performance. Females had an increased risk of cardiopulmonary sequelae, which could not be explained by treatment-related differences between the genders.

Adult↗
PubMed1996

Increased variability in bronchial responsiveness in aluminum potroom workers with work-related asthma-like symptoms.

In a longitudinal study, we studied the variability in bronchial responsiveness (BR) to methacholine in aluminum potroom workers suffering from work-related asthma-like symptoms (WASTH) and in symptom-free workers. In the index group, 26 men suffering from WASTH were selected from a cross-sectional survey. The reference group comprised 45 symptom-free men recruited from the enrollment of new employees. Bronchial responsiveness was expressed as the dose-response slope (DRS) of the line through origin and the last data point. The standard deviation of the log-transformed DRS was positively associated with symptom score (P = .012) and the mean BR (P < .001). Our results indicate that the severity of respiratory symptoms in aluminum potroom workers with WASTH reflects the variability in BR.

Adult↗
PubMed1996

Pulmonary haemodynamics after single-lung transplantation for end-stage pulmonary parenchymal disease.

In a prospective study, we investigated the effect of single-lung transplantation (SLT) on pulmonary haemodynamics and the relationship between pulmonary hypertension (PH) and the fraction of perfusion to the transplant in patients with end-stage pulmonary parenchymal disease. Twenty four SLT recipients were included in the study, 19 with chronic obstructive pulmonary disease (COPD), two with sarcoidosis and three with fibrosing alveolitis. Spirometry, determination of arterial blood gas values, perfusion scintigraphy and right heart catheterization were performed before and 1, 6, 12 and 24 months after transplantation. Patients with a mean pulmonary artery pressure (Ppa) > or = 20 mmHg before transplantation were defined as having PH (PH group, 15 patients) and the remainder (9 patients) constituted the non-PH group. In the PH group, Ppa and pulmonary vascular resistance (PVR) were significantly decreased after transplantation: 28 +/- 2 to 18 +/- 1 mmHg and 288 to 161 +/- 11 dyne.s-1.cm-5, respectively (mean +/- SEM). In the non-PH group, the haemodynamic parameters were unchanged after transplantation. Over the 2 year follow-up period, no significant change was found in Ppa and PVR, nor any difference between the PH and non-PH group. There was no significant difference between the two groups in terms of pulmonary perfusion to the graft. In conclusion, patients with pulmonary hypertension obtain pulmonary haemodynamics within the normal range after single-lung transplantation. Presence or absence of pulmonary hypertension before transplantation does not influence perfusion to the graft. These findings persist up to 2 yrs, despite the coexistence of an "end-stage" native lung and a lung transplant.

Adult↗
PubMed1996

Allergen sensitization and exposure to irritants in infancy.

We investigated the relationship between residence in the neighbourhood of an aluminium smelter and the prevalence of atopy in schoolchildren (7-13 years of age). Atopy was assessed in 556 of the 620 participants by a skin prick test with eight common aeroallergens. The median exposures to sulphur dioxide and fluoride during the pollen season in the age interval 19-36 months were 24 and 3.1 micrograms/m3 in the spring and 20 and 3.3 micrograms/m3 in the summer, respectively. The odds ratio (OR) of having atopy was 2.0 (95% CI: 1.2-3.3) in those children who had lived in the index area for 7 years or more compared with those who had lived there less than 7 years (cumulative effect). The OR of atopy was 2.5 (1.4-4.4) in those who had lived in the index area during the age interval of 19-36 months compared with rural residence during this age-interval (age-specific effect). When the age-specific effect and the cumulative effect were compared in the same logistic model, the former decreased to 1.1 (0.4-3.0), whereas the latter was 2.2 (0.7-6.6). The results indicate that exposure to these low levels of irritants during early childhood increases allergen sensitization in children.

Adolescent↗
PubMed1996

The use of isolated lung cells in in vitro pulmonary toxicology: studies of DNA damage, apoptosis and alteration of gene expression.

Isolated lung cells constitute a valuable system for studying mechanisms involved in chemically induced toxicity in the lung. Different lung cells isolated from various species may be studied. Bronchiolar Clara and alveolar type 2 cells produce important lung-specific proteins, hold a major role in the metabolism of xenobiotics and serve as progenitor cells for other lung cell types. They are possible target cells in lung carcinogenesis. Alveolar macrophages play an important role in lung defence and in inflammatory responses. In the present study we have characterised chemically induced DNA damage, apoptosis, changes in cell cycle progression, transformation and alterations in gene expression in these specific lung cells isolated from rat, rabbit and human. Major differences between the cell types and the various species in the induction of DNA damage by chemicals were found, as measured by the 32P-postlabelling and alkaline filter elution techniques. Benzo(a)pyrene and hydrogen fluoride were found to induce apoptosis in the isolated cells as measured by microscopical analysis and flow cytometry. The function of various important tissue- or cell type specific proteins (CYP 2B1, Clara cell protein) and/or cellular signal transduction pathways constitute important targets that may be affected by exposure to toxic compounds. Using immunological and molecular techniques the differential expression of specific proteins/RNAs and their activity can be studied. Among other proteins, c/ebp is involved in the regulation of transcription at the end of signal pathways. The protein is differentially expressed in rat lung cells and thus could be suitable for studying differential toxic effects in various lung cells. In humans, bronchoalveolar lavage (BAL) fluid from human volunteers can be readily obtained and examined after exposure to different chemical compounds. An increase in the percentage of CD3-positive cells (T-lymphocytes) was found after exposure to hydrogen fluoride. The number of certain cell types and cytokines may be used to estimate the degree of inflammatory reaction. In conclusion, the use of in vitro data including the use of specific, primary human lung cell types may contribute considerably to the quality of risk assessment, together with in vivo data from animals and man.

Animals↗
PubMed1995

[An answer to an inquiry on diffuse panbronchiolitis. Now it has found its way here!].

Diffuse panbronchiolitis (DPB) is a disease characterised by chronic inflammation in the region of respiratory bronchioles. The condition has mainly been observed in Japanese patients, though isolated cases have been reported from other countries. In a review published in Läkartidningen (37/94), the question was raised of why this disease had not been seen in Scandinavia, and whether this might be the result of missed diagnosis. The diagnostic criteria were listed, and the question was posed of whether (Scandinavian) physicians existed who had encountered patients with chronic sinusitis, persistent cough and inexplicable nodular changes in lung x-rays. As a direct result of this enquiry, the present article reports what may well be the first Scandinavian patient to fulfil all the diagnostic criteria of DPB. The patient responded with improved lung function and normalised blood gases to a combined treatment regimen comprising immunosuppression (cyclophosphamide and prednisolone) and nebulised antibiotics (gentamicin).

Adult↗
PubMed1995

Relation of exposure to airway irritants in infancy to prevalence of bronchial hyper-responsiveness in schoolchildren.

To find out whether exposure to sulphur dioxide during infancy is related to the prevalence of bronchial hyper-responsiveness (BHR), we studied schoolchildren (aged 7-13 years) from two areas of Norway--a valley containing a sulphur-dioxide-emitting aluminium smelter and a similar but non-industrialised valley. Bronchial responsiveness was assessed in 529 of the 620 participants. The median exposures to sulphur dioxide and fluoride were 37.1 micrograms/m3 and 4.4 micrograms/m3 at ages 0-12 months and 37.9 micrograms/m3 and 4.4 micrograms/m3 at 13-36 months. The risk of BHR increased with exposure to sulphur dioxide and fluoride at these ages; the odds ratio for a 10 micrograms/m3 increase in sulphur dioxide exposure at 0-12 months was 1.62 (95% CI 1.11-2.35) and that for a 1 microgram/m3 increase in fluoride exposure was 1.35 (1.07-1.70) at 0-12 months and 1.38 (1.05-1.82) at 13-36 months. Exposure to these low concentrations of airway irritants during early childhood is associated with an increased prevalence of BHR in schoolchildren.

Adolescent↗
PubMed1995

Bronchial responsiveness decreases in relocated aluminum potroom workers compared with workers who continue their potroom exposure.

We have compared the bronchial responsiveness (BR) of 12 aluminum potroom workers (index group) who were relocated due to work-related asthmatic symptoms (WASTH) and 26 subjects (reference group) with WASTH who continued to work in potrooms. The subjects were examined at regular intervals during a 2-year follow-up period. BR was expressed as the log-transformed dose-response slope [Ln(DRS 5)]. The monthly change in BR (delta BR) in the index group was -4.87 x 10(-2) compared with -1.58 x 10(-2) in the reference group. After adjustment for potential confounders, the difference between the index group and the reference group was -2.39 x 10(-2) (95% CI: -4.07 x 10(-2) to -0.71 x 10(-2)), i.e. 49% of the decrease in BR in the index group could be explained by the removal from exposure. No improvement in lung function was found in the index group compared with the reference group. The results indicate that the removal of potroom workers from exposure causes a decrease in BR.

Adult↗