Paper mill workers are exposed to culturable microorganisms (MOs). We hypothesized that inflammatory airway response could be detected in sputum of nonsymptomatic workers. From four paper mills, we included 29 healthy nonsmoking men. Workers exposed to high levels of MOs (HMOE, n = 17) were compared with workers exposed to low levels of MO (LMOE, n = 12). A reference group of 22 healthy, nonsmoking, nonexposed (NE) men were also included. We performed differential cell counts of induced sputum, studied gene expressions of isolated sputum macrophages and analyzed inflammatory parameters, including matrix metalloproteinases. Sputum from HMOE workers had a significantly higher percentage of neutrophils than that from LMOE workers (P
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).
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.
After adjustment for confounders, the difference in dFEV1 and dFVC between the index and reference groups were 13.5 (P?
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We have investigated the association between respiratory symptoms and dust exposure among employees in 18 Norwegian smelters using a longitudinal design.
All employees (N = 3,084) were examined annually for 5 years (12,996 health examinations). At each examination, the subjects reported if they had respiratory symptoms, coded as 1 (yes) or 0 (no), on a respiratory questionnaire. Symptom score was constructed as the sum of symptoms (0-5). Full-time workers in the production line were classified as line operators; subjects never exposed in the production line were regarded as non-exposed. The remaining individuals were classified as non-line operators. A job-exposure matrix regarding dust exposure was also available. Analyses of repeated measurements were performed using generalised linear mixed model with log-link (Poisson regression). Adjustments were made for overdispersion.
The mean age at inclusion was 39.0 years, and 89% were men. The median dust exposure in tertiles 1-3 was 0.19, 1.76 and 3.47 mg/m(3). The longitudinal analyses showed that the association between symptoms-score ratio (SSR) and job category was significantly stronger in dropouts compared with non-dropouts (p = 0.01). Among the dropouts, SSR was 1.61 (95% confidence interval: 1.27-2.05) and 1.39 (1.09-1.77) in line operators and non-line operators compared with non-exposed employees, respectively. The corresponding SSR for subjects who completed the study was 1.13 (1.01-1.27) and 1.12 (1.00-1.26), respectively. Similarly, among the dropouts, the SSR between the second and the first tertile was 1.28 (1.05-1.55) and 1.37 (1.13-1.66) between the third tertile and the first tertile.
Line operators had more respiratory symptoms than non-exposed employees. This effect was significantly stronger in dropouts than in those who continued their jobs, indicating that there is a selection of subjects without respiratory symptoms in this industry.
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BACKGROUND: The main objective of the present study was to investigate whether exposure to bitumen fumes could enhance the risk of cancer in asphalt workers. METHODS: A historical prospective cohort study was performed including 8,763 male asphalt workers from all main asphalt companies in Norway. Name, date of birth, and unique personal identification number, address, job type, and start and stop of employment in specific jobs was obtained for the workers. Information was complied from payroll and personnel records in the companies. The cohort was then linked to the Cancer Registry of Norway, which has complete records of individual cases of cancer in the Norwegian population since 1953. Follow-up was from 1 January 1970 to 31 December 1997. The 5-year age and period adjusted general male population in Norway served as reference population. RESULTS: Lung cancer was found elevated with standardized incidence ratio (SIR) = 1.3 (95% confidence intervals (CI) = 1.1, 1.7) in the overall analysis. Lung cancer was found more elevated in workers first exposed in the 1950s and 1960s and in mastic asphalt workers (SIR = 4.2, 95% CI = 1.2, 10, based on four cases) and pavers (SIR = 1.4, 95% CI = 1.0, 1.9). There was a deficiency in the incidence of malignant melanoma with 13 cases versus 26 expected. CONCLUSIONS: Risk of lung cancer was found enhanced among the asphalt workers. Some of the enhanced risk could probably be explained by the smoking habits of the workers. Exposure to coal tar may also have contributed to the enhanced risk.
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.
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.
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.
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.
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RATIONALE: The relationship between dust exposure and annual decline in lung function among employees in the smelting industry is unknown. OBJECTIVES: The aim of the study was to investigate the relationship between annual change in lung function and occupational dust exposure among workers in 15 Norwegian smelters. METHODS: All employees (n = 2,620) were examined annually for 5 years (11,335 health examinations). At each examination spirometry was performed and a respiratory questionnaire was completed. The smelters were grouped as follows: (1) ferrosilicon alloys (FeSi) and silicon metal (Si-metal); and (2) silicon manganese (SiMn), ferromanganese (FeMn), and ferrochromium (FeCr). A job exposure matrix was available on the basis of 2,619 personal dust exposure measurements. The association between lung function expressed as FEV(1) and FVC per squared height (height(2)) and dust exposure was investigated using multivariate linear mixed model analyses. MEASUREMENTS AND MAIN RESULTS: The annual change in FEV(1)/height(2) (deltaFEV(1)) related to dust exposure in the FeSi/Si-metal and SiMn/FeMn/FeCr smelters was -0.42 (95% confidence interval, -0.95 to 0.11) and -1.1 (-2.1 to -0.12) (ml/m(2)) x (mg/m(3))(-1) x year(-1), respectively. The annual decline in FEV(1)/height(2) was 1.6 ml/m(2) (0.15 to 3.1) steeper in smokers than in nonsmokers. The median geometric mean of the time-weighted dust exposure concentration levels of the employees was 2.3 mg/m(3) in the FeSi/Si-metal smelters and 1.6 mg/m(3) in the SiMn/FeMn/FeCr smelters. Among nonsmokers, deltaFEV(1) was -0.86 (-1.6 to -0.10) and -1.1 (-2.5 to 0.25) (ml/m(2)) x (mg/m(3))(-1) x year(-1) in the FeSi/Si-metal and SiMn/FeMn/FeCr smelters, respectively. Thus, for a 1.80 m tall employee the annual decline in FEV(1) associated with average dust exposure was 5.7 ml/year in the SiMn/FeMn/FeCr smelters, and 6.4 ml/year for a nonsmoker in the FeSi/Si-metal smelters. CONCLUSIONS: In all smelters combined, the annual change in FEV(1) was negatively associated with increasing dust exposure. This association was also significant among workers in SiMn/FeMn/FeCr smelters and among nonsmokers in the FeSi/Si-metal smelters.
RefSource: Am J Respir Crit Care Med. 2010 Jun 1;181(11):1162-3
To investigate the relationship between dust exposure and annual change in lung function among employees in Norwegian silicon carbide (SiC) plants using a quantitative job exposure matrix (JEM) regarding total dust.
All employees, 20-55 years of age by inclusion (n=456), were examined annually for up to 5 years (1499 examinations). Spirometry was performed at each examination, and a questionnaire encompassing questions of respiratory symptoms, smoking status, job and smoking history, and present job held was completed. A JEM was constructed based on 1970 personal total dust exposure measurements collected during the study period. The association between lung function and total dust exposure was investigated using linear mixed models.
The annual change in forced expiratory volume (FEV) in one second per squared height, FEV1/height(2), per mg/m(3) increase in dust exposure was -2.3 (95% CI -3.8 to -0.79) (mL/m(2))×year(-1). In an employee of average height (1.79 m) and exposure (1.4 mg/m(3)) the estimated contribution to the annual change in FEV1 associated with dust was 10.4 mL/year. The annual change in FEV1/height(2) in current, compared with non-smokers was -1.9 (-7.2 to 3.4) (mL/m(2))×year(-1). The estimated overall annual decline in FEV1 among current and non-smokers in the highest exposed group was -91.2 (-124.3 to -58.1) (mL/m(2))×year(-1) and -49.0 (-80.2 to -17.8) (mL/m(2))×year(-1), respectively.
Dust exposure, expressed by a quantitative JEM, was found to be associated with an increased yearly decline in FEV1 in employees of Norwegian SiC plants.
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.
The long-term prognosis of repeated acute episodes of hypersensitivity pneumonitis (HP) is not well described. We report on a 10-year follow-up of a 10-person cluster from a Norwegian sawmill who had all experienced relapsing episodes of HP.
To evaluate the health symptoms, work-related sick-leave, and lung function of 10 workers exposed to mold in a Norwegian sawmill.
Participants were evaluated at baseline and 10 years later at follow-up. A structured interview, measurement of serum IgG antibodies to Rhizopus microsporus (R. microsporus) antigens, lung function tests, high resolution computed tomography (HRCT) of the chest, and personal measurements of exposure to mold spores and dust were completed for each participant.
At baseline, nearly all workers reported acute episodes of HP more than twice a month. At follow-up, both the frequency and intensity of symptoms had declined. Sick-leave was reduced and gas diffusing capacity improved - paralleling the gradually reduced air levels of mold spores.
In spite of an initially high occurrence of symptoms, long-term clinical and physiological outcome was good. With reduced exposure to mold spores, symptoms declined and lung function was restored.
We have investigated the association between the incidence of airflow limitation and occupational exposure. The employees (n?=?3,924) were investigated annually during five years (n?=?16,570) using spirometry. Exposure was classified using job category and a job exposure matrix. Airflow limitation was expressed using two indices: (i) as forced expiratory volume in one second/force vital capacity (FEV(1) /FVC)