Comparison of different reference values for lung function: implications of inconsistent use among centers.

BACKGROUND: For interpretation of pulmonary function tests (PFTs), reference values based on sex, age, height and ethnicity are needed. In Norway, the European Coal and Steel Community (ECSC) reference values remain widely used, in spite of recommendations to implement the more recent Global Lung Function Initiative (GLI) reference values. OBJECTIVE: To assess the effects of changing from ECSC to GLI reference values for spirometry, DLCO and static lung volumes, using a clinical cohort of adults with a broad range in age and lung function. METHODS: PFTs from 577 adults (18-85 years, 45% females) included in recent clinical studies were used to compare ECSC and GLI reference values for FVC, FEV1, DLCO, TLC and RV. Percent predicted and lower limit of normal (LLN) were calculated. Bland-Altman plots were used to assess agreement between GLI and ECSC % predicted values. RESULTS: In both sexes, GLI % predicted values were lower for FVC and FEV1, and higher for DLCO and RV, compared to ECSC. The disagreement was most pronounced in females, with mean (SD) difference 15 (5) percent points (pp) for DLCO and 17 (9) pp for RV (p < 0.001). With GLI, DLCO was below LLN in 23% of the females, with ECSC in 49% of the females. CONCLUSIONS: The observed differences between GLI and ECSC reference values are likely to entail significant consequences with respect to criteria for diagnostics and treatment, health care benefits and inclusion in clinical trials. To ensure equity of care, the same reference values should be consistently implemented across centers nationwide.

Late-Onset, Noninfectious Pulmonary Complications following Allogeneic Hematopoietic Stem Cell Transplantation: A Nationwide Cohort Study of Long-Term Survivors.

BACKGROUND: Survivors of allogeneic hematopoietic stem cell transplantation (allo-HSCT) are at risk for pulmonary adverse events. Data on late-onset noninfectious pulmonary complications in long-term adult survivors of allo-HSCT are limited and incomplete. OBJECTIVES: This study aimed (1) to determine occurrence and degree of pulmonary sequelae in adult survivors of allo-HSCT and (2) to identify associations between pulmonary function, high-resolution CT (HRCT), and clinical characteristics. METHOD: In a nationwide, single-center cross-sectional study, 103 survivors (aged median [range] 35 [17-58] years, 53% females) were examined 17 (6-32) years after allo-HSCT and compared with healthy controls (n = 105). Methods included pulmonary function tests and HRCT. RESULTS: Chronic graft-versus-host disease was diagnosed in 33% of survivors, including 12% with bronchiolitis obliterans syndrome (BOS). Mean lung volumes (TLC, FVC, and FEV1) and gas diffusing capacity were >80% of predicted for the survivors as a group, but significantly lower than in healthy controls. Pathological HRCT findings were detected in 48% of the survivors (71% airways disease, 35% interstitial lung disease, and 24% apical subpleural interstitial thickening). Air trapping (%) on HRCT correlated with % predicted FEV1, p < 0.001. In a multiple logistic regression model, both BOS and pathological findings on HRCT were associated with chemotherapy prior to allo-HSCT, p < 0.05. CONCLUSIONS: Long-term allo-HSCT survivors had significantly lower pulmonary function than age- and gender-matched healthy controls and nearly half had pathological findings on HRCT. Longitudinal data will determine if pulmonary sequelae will remain stable or progress. We recommend lifelong monitoring of pulmonary function in allo-HSCT survivors. HRCT provides additional information, but is not suited for surveillance.

Relation of sputum neutrophilia to the development of chronic lung allograft dysfunction after lung transplantation.

Chronic lung allograft dysfunction (CLAD) is a serious complication after lung transplantation (LuTx) and is associated with elevated proportions of neutrophils in bronchoalveolar lavage (BAL). Induced sputum is a less-invasive sampling method than BAL and assesses markers of inflammation on the surfaces of large central airways. We wanted to examine whether % neutrophil levels in induced sputum were elevated prior to CLAD diagnosis among LuTx recipients, and whether sputum markers of inflammation can be used as a tool for predicting the development of CLAD. Induced sputum samples were collected at 1, 3, 6, 12, and 24 months post-LuTx in 36 patients with a history of COPD or pulmonary fibrosis, and of these, 16 developed CLAD either during or after the sputum surveillance period. At 2 years, median (IQR) % neutrophils in induced sputum were significantly higher among patients with CLAD compared with those without CLAD [73 (52-80) % vs 59 (41-76) %, p = .01]. Interestingly, we found a significant increase in the rate of change in % neutrophils beginning at 90 days preceding the diagnosis of CLAD. This suggests using sputum neutrophil percentage as a surveillance modality for monitoring lung allograft function after LuTx.

Effect of high-intensity training on bone health and body composition in lung transplant recipients: A secondary analysis of a randomized controlled trial.

BACKGROUND: Loss of bone mineral and skeletal muscle mass is common after lung transplantation (LTx), and physical activity (PA) may prevent further deterioration. We aimed to assess the effects of 20-week high-intensity training (HIT) on body composition, bone health, and PA in LTx recipients, 6-60 months after surgery. METHODS: In a randomized controlled trial, 51 LTx recipients underwent Dual-energy X-ray absorptiometry (DXA), and PA level and sedentary time were objectively recorded by accelerometers for seven consecutive days. Of these, 39 participants completed the study, including 19 participants in the HIT group and 20 participants in the standard care group. RESULTS: Following the intervention, ANCOVA models revealed a nonsignificant between-group difference for change in lean body mass (LBM) and bone mineral density (BMD) of the lumbar spine of 0.4% (95% CI = -3.2, 1.5) (p = .464) and 1.0% (95% CI=-1.3, 3.4) (p = .373), respectively. Trabecular bone score (TBS) of the lumbar spine (L1-L4), however, increased by 2.2 ± 5.0% in the exercise group and decreased by -1.6 ± 5.9% in the control group, giving a between-group difference of 3.8% (95% CI=0.1, 7.5) (p = .043). There were no between-group differences in PA or sedentary time. CONCLUSION: High-intensity training after LTx improved TBS significantly, but not PA, LBM or BMD.

Determinants of cardiorespiratory fitness in very long-term survivors of allogeneic hematopoietic stem cell transplantation: a national cohort study.

PURPOSE: Survivors of allogeneic hematopoietic stem cell transplantation (allo-HSCT) are at risk for cardiopulmonary adverse events. Data on long-term effects on cardiorespiratory fitness are limited. To address the gap in knowledge, we aimed to determine peak oxygen uptake (V̇O2peak) and identify associations between cardiorespiratory fitness and clinical characteristics, self-reported physical activity, cardiac, and pulmonary function. METHODS: In a nationwide, single-center cross-sectional study, 90 survivors [aged median (range) 35 (17-54) years, 56% females] were examined, 17 (6-26) years after allo-HSCT. Myeloablative conditioning comprised busulfan/cyclophosphamide or cyclophosphamide only. Methods included pulmonary function tests, echocardiography, and cardiopulmonary exercise test. RESULTS: Chronic graft-versus-host disease (cGVHD) was found in 31% of the subjects, of whom 40% had bronchiolitis obliterans syndrome (BOS). Seventy-one percent of the survivors did not meet WHO recommendations for physical activity and 42% were overweight. Reduced gas diffusion (DLCO) and systolic ventricular dysfunction (LVEF) were found in 44% and 31%, respectively. For the group, mean (95% CI), V̇O2peak was 36.4 (34.7-38.0) mL/min/kg [89 (85-93)% of predicted]. V̇O2peak was low at 43%. Cardiopulmonary factors and deconditioning were equally common limitations for exercise. In a multiple linear regression model, low V̇O2peak was associated with low DLCO, low LVEF, BOS, overweight, and inactivity. CONCLUSION: Half of the survivors had reduced cardiorespiratory fitness median 17 years after allo-HSCT. Cardiopulmonary factors and deconditioning were equally common limitations to exercise. We encourage long-term cardiopulmonary monitoring of allo-HSCT survivors and targeted advice on modifiable lifestyle factors.

Cardiorespiratory Fitness and Physical Activity following Lung Transplantation: A National Cohort Study.

BACKGROUND: Low cardiorespiratory fitness and inactivity are common after lung transplantation (LTx). The causes of exercise intolerance are incompletely understood. OBJECTIVES: The aim of this study was to objectively assess cardiorespiratory fitness and physical activity, evaluate causes of exercise intolerance, and explore clinical factors associated with cardiorespiratory fitness after bilateral LTx (BLTx). MATERIALS AND METHODS: Peak oxygen uptake (V∙O2peak) and exercise-limiting factors were evaluated by a treadmill cardiopulmonary exercise test (CPET) 6-60 months after BLTx. Physical activity was measured with accelerometers, and results were compared with Norwegian normative data and the World Health Organization's (WHO) recommendations for physical activity. RESULTS: In 54 included BLTx recipients (mean age 50 ± 15 years, 50% females), V∙O2peak (mL × kg-1 × min-1) was 21.8 ± 7.7 for men and 22.4 ± 6.2 for women, corresponding to 57 ± 17 and 70 ± 12% of predicted, respectively. Three patients (6%) met criteria for normal V∙O2peak. Deconditioning limited V∙O2peak in 22 patients (41%), while ventilatory limitation and abnormal gas exchange were observed in 14 (26%) and 20 (37%) patients, respectively (some had more than 1 finding). Forty-three patients (86%) did not meet the WHO physical activity recommendations. There was a moderate correlation between V∙O2peak and physical activity (r = 0.642, p < 0.01). Body mass index, physical activity, forced expiratory volume after 1 second, sex, and hemoglobin together accounted for 73% of the variability in V∙O2peak. CONCLUSIONS: Low cardiorespiratory fitness was observed in the majority of BLTx recipients. Both deconditioning and cardiopulmonary limitations were common findings. Nearly 90% were classified as being inactive according to physical activity recommendations. CPET appears to identify a deconditioned subgroup of BLTx recipients for whom exercise training may be especially beneficial.

Influence of Obesity on Work Ability, Respiratory Symptoms, and Lung Function in Adults with Asthma.

BACKGROUND: Asthma is defined by variable respiratory symptoms and lung function, and may influence work ability. Similarly, obesity may contribute to respiratory symptoms, affect lung function, and reduce work ability. Thus, assessment of the influence of obesity on work ability, respiratory symptoms, and lung function in adults with asthma is needed. OBJECTIVES: We hypothesized that patients with obesity and asthma have more respiratory symptoms and reduced work ability and lung function compared with normal-weight patients with asthma. METHODS: We examined 626 participants with physician-diagnosed asthma, aged 18-52 years, recruited from a cross-sectional general population study using a comprehensive questionnaire including work ability score, the asthma control test (ACT), height and weight, and spirometry with reversibility testing. RESULTS: Participants with a body mass index (BMI) ≥30 kg/m2 (i.e., obese) had a higher symptom score (OR 1.78, 95% CI 1.14-2.80), current use of asthma medication (1.60, 1.05-2.46), and incidence of ACT scores ≤19 (poor asthma control) (1.81, 1.03-3.18) than participants with BMI ≤24.9 kg/m2 (i.e., normal weight). Post-bronchodilator forced vital capacity (FVC) as a percentage of predicted (ß coefficient -4.5) and pre-bronchodilator forced expiratory volume in 1 s as a percentage of predicted (FEV1) (ß coefficient -4.6) were negatively associated with BMI ≥30 kg/m2. We found no statistically significant association of BMI >30 kg/m2 (compared to BMI <24.9 kg/m2) with sick leave (1.21, 0.75-1.70) or reduced work ability (1.23, 0.74-2.04). CONCLUSIONS: There were indications that patients with obesity had a higher symptom burden, poorer asthma control, higher consumption of asthma medication, and reduced lung function, in particular for FVC, compared with normal-weight patients.

Annual decline in forced expiratory volume and airway inflammatory cells and mediators in a general population-based sample.

BACKGROUND: Few studies have examined the relationships between sputum inflammatory markers and subsequent annual decline in forced expiratory volume in 1 s (dFEV1). This study investigated whether indices of airway inflammation are predictors of dFEV1 in a general population-based sample. METHODS: The study, conducted from 2003 to 2005, included 120 healthy Norwegian subjects aged 40 to 70 years old. At baseline, the participants completed a self-administered respiratory questionnaire and underwent a clinical examination that included spirometry, venous blood sampling, and induced sputum examination. From 2015 to 2016, 62 (52%) participants agreed to a follow-up examination that did not include induced sputum examination. Those with a FEV1/forced vital capacity (FVC) ratio <  0.70 underwent a bronchial reversibility test. The levels of cytokines, pro-inflammatory M1 macrophage phenotypes were measured in induced sputum using bead-based multiplex analysis. The associations between cytokine levels and dFEV1 were then analysed. RESULTS: The mean dFEV1 was 32.9 ml/year (standard deviation 26.3). We found no associations between dFEV1 and the baseline indices of sputum inflammation. Seven participants had irreversible airflow limitation at follow-up. They had lower FEV1 and gas diffusion at baseline compared with the remaining subjects. Moreover, two of these individuals had a positive reversibility test and sputum eosinophilia at baseline. CONCLUSIONS: In this cohort of presumably healthy subjects, we found no associations between sputum inflammatory cells or mediators and dFEV1 during 10 years of follow-up.

Risk factors for impaired pulmonary function and cardiorespiratory fitness in very long-term adult survivors of childhood acute lymphoblastic leukemia after treatment with chemotherapy only.

BACKGROUND: Survivors of childhood acute lymphoblastic leukemia (ALL) are at risk of late treatment-related side-effects. Data regarding prevalence and risk factors for impairments in pulmonary function and cardiorespiratory fitness are limited, and reported findings are inconsistent and inconclusive. MATERIAL AND METHODS: In a cross-sectional study, 116 ALL survivors (median 5 years at diagnosis, 29 years at follow-up, 53% females) were examined, median 23 years after treatment with chemotherapy only. Individual cumulative doses of cytostatic agents were calculated. Methods included blood tests, echocardiography, pulmonary function tests and cardiorespiratory exercise test. RESULTS: Females had lower % predicted gas diffusing capacity (DLCO) than males (mean [SD] 84 [13] versus 97 [14], p < .001). Impairment in DLCO was found in 34% females versus 7% males, p < .001. In a multiple linear regression model, female gender, body mass index (BMI) and smoking were risk factors for reduced % predicted DLCO, with a borderline significant effect of left ventricular ejection fraction (LVEF). Impaired cardiorespiratory fitness was found in 42% of the survivors, with a borderline increased risk in females, p = .06. Smoking and BMI were risk factors for reduced % predicted VO2peak. Subjects exposed to anthracyclines had lower LVEF% and % predicted VO2peak than those not exposed, (mean [SD] 56.2 [4.3] versus 59.2 [5.2], p = .01 and 86.9 [18.4] versus 92.8 [18.4], p = .03, respectively). CONCLUSIONS: Impairments in pulmonary function and cardiorespiratory fitness are common in very long-term survivors of childhood ALL. Risk factors are female gender, BMI and smoking. In order to preserve pulmonary function and cardiorespiratory fitness, we suggest increased attention and targeted advice on modifiable lifestyle factors such as smoking, inactivity and overweight.

Gender-specific survival after surgical resection for early stage non-small cell lung cancer.

BACKGROUND: Lung cancer is the leading cause of cancer death worldwide. The incidence and mortality rate of lung cancer in women has increased. Studies have indicated that females with non-small cell lung cancer (NSCLC) have better survival than males. We aimed to examine the impact of gender on 1-, 5- and 10-year survival after surgery for stage I and II NSCLC. MATERIALS AND METHODS: During the period 2003-2013, 692 patients operated for stage I and II NSCLC were prospectively registered. Patients were stratified into four groups according to gender and age over or less than 66 years. The relationship between gender and age on overall survival was investigated. Adjustment for multiple confounders was performed using the Cox proportional hazard regression model. RESULTS: Surgical resection was performed in 368 (53.2%) males and 324 (46.8%) females. During the study period, mortality was 35.2% in younger females, 34.9% in younger males, 42.8% in older females and 51.2% in older males. Stratified by age, there were no significant gender differences with regard to survival [hazard ratio (HR) 1.16, 95% confidence interval (CI) 0.91-1.46, p = .23]. Comparing the younger and the older patients adjusted for confounders, the mortality risk was significantly increased in elderly patients [females, adjusted HR 1.60, 95% CI 1.12-2.28]. Compared with population data, standardized mortality ratio was increased to 4.1 (95% CI 3.5-4.7) in males and to 6.5 (95% CI 5.4-7.6) in females. CONCLUSION: Overall survival did not differ significantly between males and females. Adjusted for confounding factors, we found a significantly increased mortality risk in elder patients compared to their younger counterparts. However, five-year overall survival of more than 50% for older patients with NSCLC should encourage surgical treatment also in elderly lung cancer patients.

Military small arms fire in association with acute decrements in lung function.

OBJECTIVE: After introduction of unleaded ammunition, Norwegian Armed Forces received reports of acute respiratory symptoms in soldiers after exposure to fumes from firing the standard weapon, HK416. The aim of the present study was to examine lung function before and after exposure to fumes from HK416 in a double-blinded standardised study design using three different types of ammunition. METHODS: Fifty-four healthy, non-smoking male volunteers (19-62 years) fired the weapons for 60 min with either leaded, unleaded or 'modified' unleaded ammunition. Gaseous and particulate emissions were monitored. Spirometry and exhaled nitric oxide (eNO) were performed within 14 days before (T0), shortly after (T1) and 24 hours after (T2) shooting. Methacholine provocation and diffusing capacity of carbon monoxide (DLCO) were carried out at T0 and T2. RESULTS: The mean forced expiratory volume in 1 s on a group level was significantly reduced both at T1 and T2 compared with T0, with means and 95% CI of 226 mL (158 to 294 mL) and 285 mL (218 to 351 mL), respectively. The same significant pattern was seen for DLCO, forced vital capacity and eNO. The methacholine test indicated a slight increase in bronchial hyper-reactivity. However, there were no significant differences between types of ammunition used. CONCLUSION: Exposure to fumes from military weapons might be a respiratory hazard for soldiers who do live-fire training regularly or are in a closed combat environment.

Thoracic dust exposure is associated with lung function decline in cement production workers.

We hypothesised that exposure to workplace aerosols may lead to lung function impairment among cement production workers.Our study included 4966 workers in 24 cement production plants. Based on 6111 thoracic aerosol samples and information from questionnaires we estimated arithmetic mean exposure levels by plant and job type. Dynamic lung volumes were assessed by repeated spirometry testing during a mean follow-up time of 3.5 years (range 0.7-4.6 years). The outcomes considered were yearly change of dynamic lung volumes divided by the standing height squared or percentage of predicted values. Statistical modelling was performed using mixed model regression. Individual exposure was classified into quintile levels limited at 0.09, 0.89, 1.56, 2.25, 3.36, and 14.6 mg·m(-3), using the lowest quintile as the reference. Employees that worked in administration were included as a second comparison group.Exposure was associated with a reduction in forced expiratory volume in 1 s (FEV1), forced expiratory volume in 6 s and forced vital capacity. For FEV1 % predicted a yearly excess decline of 0.84 percentage points was found in the highest exposure quintile compared with the lowest.Exposure at the higher levels found in this study may lead to a decline in dynamic lung volumes. Exposure reduction is therefore warranted.

Sputum neutrophils are elevated in smelter workers, and systemic neutrophils are associated with rapid decline in FEV1.

OBJECTIVES: In a previous study on smelter workers we, found significant relationship between exposure to dust and accelerated annual decline in forced expiratory volume in 1 s (FEV1). In this cross-sectional study at the end of a follow-up, we aimed to investigate the possible association between annual decline in FEV1 and markers of airways, and systemic inflammation in smelter workers. METHODS: Employees (n=76 (27 current smokers)) who had been part of a longitudinal study (9-13 years) that included spirometry (>6 measurements) and respiratory questionnaires, performed induced sputum, exhaled NO and had blood drawn. Participants with annual decline in FEV1≥45 mL were compared with participants with annual decline <45 mL; also 26 non-exposed controls were included. RESULTS: Compared with non-exposed controls, smelter workers demonstrated a significantly increased percentage of neutrophils (mean (SD)) (57% (17) vs 31% (15)) and matrix metalloproteinases 8 (MMP-8) levels in sputum, and MMP-9, surfactant protein D (SpD) and transforming growth factor ß (TGFb) levels in blood. A significant association in FEV1≥45 mL was found for blood neutrophils when controlling for smoking habits (OR=1.7 (95% CI 1.0 to 2.8), p=0.045). Airway and blood protein markers were not associated with annual decline in FEV1. CONCLUSIONS: All workers displayed airway and systemic inflammation characterised by increased levels of neutrophils and MMP-8 in sputum, and MMP-9, SpD and TGFß in blood compared with non-exposed controls. Blood neutrophils in particular were significantly elevated in those workers with the most rapid decline in lung function. A similar observation was not seen with airway neutrophils. In the present study, we were able to identify systemic but not airway inflammatory markers that can predict increased decline in FEV1 in smelter workers.

Annual decline in forced expiratory volume is steeper in aluminum potroom workers than in workers without exposure to potroom fumes.

BACKGROUND: Aluminum potroom exposure is associated with increased mortality of COPD but the association between potroom exposure and annual decline in lung function is unknown. We have measured lung volumes annually using spirometry from 1986 to 1996. The objective was to compare annual decline in forced expiratory volume in 1 s (dFEV1) and forced vital capacity (dFVC). METHODS: The number of aluminum potroom workers was 4,546 (81% males) and the number of workers in the reference group was 651 (76% males). The number of spirometries in the index group and the references were 24,060 and 2,243, respectively. RESULTS: After adjustment for confounders, the difference in dFEV1 and dFVC between the index and reference groups were 13.5 (P < 0.001) and -8.0 (P = 0.060) ml/year. CONCLUSION: Aluminum potroom operators have increased annual decline in FEV1 relative to a comparable group with non-exposure to potroom fumes and gases.

Occurrence, Characteristics, and Predictors of Pain in Patients with Chronic Obstructive Pulmonary Disease.

Few studies have provided a detailed characterization of pain in patients with chronic obstructive pulmonary disease (COPD). The aims of this cross-sectional study were to describe the occurrence, intensity, locations, and level of interference associated with pain, as well as pain relief; to identify differences in demographic, clinical, and symptom characteristics between COPD patients with and without pain; and to determine which demographic, clinical, and symptom characteristics were associated with average pain, worst pain, and pain interference. A total of 258 patients with COPD provided information on demographic characteristics; comorbidities; respiratory parameters including dyspnea; body mass index; and symptom characteristics (i.e., anxiety, depression, sleep disturbance, and fatigue). Pain was measured using the Brief Pain Inventory. Of these 258 COPD patients, 157 (61%) reported pain. Multiple linear regression analyses were performed to determine which demographic, clinical, and symptom characteristics were associated with average pain severity, worst pain severity, and mean pain interference. Lower stages of COPD were associated with higher worst pain and higher pain interference scores. Higher depression scores were associated with higher average pain and higher pain interference scores. In addition, higher number of pain locations was associated with higher average and higher worst pain severity scores. Findings from this study confirm that pain is a significant problem and highlights the need for specific pain management interventions for patients with COPD. More research is needed about specific pain characteristics and symptoms to gain an increased knowledge about the causes of pain in these patients.

Airway inflammation and ammonia exposure among female Palestinian hairdressers: a cross-sectional study.

OBJECTIVES: Little is known about the working conditions and airway inflammation in hairdressers in Palestine. We aimed to investigate if hairdressers in Palestine have a higher level of airway inflammation as compared to a control group. We also assessed the hairdressers' physical working conditions and exposure to ammonia gases at the hair salons. Lastly, we investigated the association between ammonia levels and inflammation markers in the airways and the blood. METHODS: Our study participants were 33 non-smoking hairdressers (aged 19-50 years) and 35 non-smoking control subjects (aged 18-49 years). Both groups answered a questionnaire on respiratory symptoms, and performed lung function and exhaled nitric oxide (eNO) tests. Blood and sputum samples were collected from all participants and air concentration levels of ammonia were measured in 13 salons. RESULTS: Hairdressers had a higher level of sputum neutrophil count (absolute numbers/mg sputum (median (25th-75th centiles)) compared to controls, 376 (183-980) and 182 (96-358), respectively. Hairdressers also had significantly elevated eNO and blood C reactive protein (CRP) levels compared to the control subjects, controlled for age and body mass index. Exposure measurements showed that the hairdressers in salons with scarce ventilation were exposed to ammonia concentration, ranging from 3 to 61 mg/m(3). CONCLUSIONS: Compared to unexposed controls, the hairdressers had signs of neutrophilic airway inflammation, higher eNO levels and higher CRP. The hairdressers were exposed to high concentrations of ammonia from hairdressing chemicals and their working conditions were unsatisfactory.

Construction of a Job Exposure Matrix to Dust, Fluoride, and Polycyclic Aromatic Hydrocarbons in the Norwegian Aluminum Industry using Prediction Models.

BACKGROUND: The Norwegian aluminum industry developed and implemented a protocol for prospective monitoring of employees' exposure using personal samplers. We analyzed these data to develop prediction lines to construct a job exposure matrix (JEM) for the period 1986-1995. METHODS: The protocol for personal monitoring of exposure was implemented in all seven Norwegian aluminum plants in 1986 and continued until 1995. Personal samplers were used to collect total dust, fluorides, and total polycyclic aromatic hydrocarbons (PAH). In addition, exposure could be categorized according to process, i.e. prebake, Søderberg, and 'other'. We constructed four-dimensional JEMs characterized by: Plant, Job descriptor, Process, and Year. Totally 8074, 6734, and 3524 measurements were available for dust, fluorides, and PAH, respectively. The data were analyzed using linear mixed models with two-way interactions. The models were assessed using the Akaike criterion (AIC) and unadjusted R (2). The significance level was set to 10% (two-sided) for retaining variables in the model. RESULTS: In 1986, the geometric mean (95% confidence interval in parentheses) for total dust, total fluorides, and PAH were 3.18 (0.46-22.2) mg m(-3), 0.58 (0.085-4.00) mg m(-3), and 33.9 (2.3-504) µg m(-3), respectively. During 10 years of follow-up, the exposure to total dust, fluorides, and PAH decreased by 9.2, 11.7, and 14.9% per year, respectively. Each model encompassed from 49 to 72 significant components of the interaction terms. The interaction components were at least as important as the main effects, and 65 to 91% of the significant components of the interaction terms were time-dependent. CONCLUSION: Our prediction models indicated that exposures were highly time-dependent. We expect that the time-dependent changes in exposure are of major importance for longitudinal studies of health effects in the aluminum industry.

Health effects after firing small arms comparing leaded and unleaded ammunition.

A number of Norwegian soldiers have reported health problems after live-fire training using the HK416 rifle. The objective of this study was to characterize gaseous and particulate emissions from three different types of ammunition, and record the health effects after exposure to emissions from live-firing. Fifty-five healthy, non-smoking men (mean age 40 years) were recruited and divided randomly into three groups, one for each type of ammunition. All subjects fired the HK416 rifle in a semi-airtight tent for 60 min using leaded ammunition, unleaded ammunition and modified unleaded ammunition. Gaseous and particulate emissions were monitored within the tent. The symptoms experienced by the subjects were recorded immediately after and the day after firing using a standardized questionnaire. The concentrations of particulate matter and copper exceeded their respective occupational exposure limits (eight hours per day, five days a week) by a factor of 3 and 27, respectively. Of the 55 subjects, 54 reported general and respiratory symptoms. The total number of symptoms reported was significantly higher among shooters using unleaded ammunition as compared with the use of leaded and modified unleaded ammunition. Copper was the substance that had the highest concentration relative to its toxicity. Although the general symptoms were found to be consistent with the development of metal fume fever, the respiratory symptoms indicated an irritant effect of the airways different from that seen in metal fume fever. More symptoms were reported when unleaded ammunition was used compared with leaded and modified unleaded ammunition.