This investigation describes benzo(a)pyrene (BP) serum protein adduct concentrations in 45 foundry workers and 45 matched non-occupationally exposed controls. High and low BP exposure groups were defined using breathing zone hygienic samples for both quartz and BP exposures. A newly developed enzyme linked immunosorbent assay detected benzo(a)pyrenediolepoxide-I binding to serum protein. Mean BP protein adduct concentrations (SD) for non-smoking (24.0 BP equivalents/100 micrograms protein (21.0] and smoking (28.0 (18.2] foundry workers were significantly higher than mean values for non-smoking (7.23 (8.72] and smoking (14.2 (24.4] controls. Foundry workers with high exposures to either quartz (28.4 (15.5] or BP (30.7 (19.3] had slightly raised mean adduct concentrations compared with foundry workers with low exposure for quartz (23.9 (23.1] or BP (24.5 (19.4). Highest mean adduct concentrations were found among a small group of workers with simultaneous high exposures to both quartz and BP (39.2 (6.5] suggesting an additive effect. These data support the ideas of a possible aetiological connection between an increased risk of lung cancer and BP exposure among foundry workers, and an additive effect between BP and quartz. Measurement of BP serum protein adduct concentrations appears to be a useful method by which groups exposed to BP may be biologically monitored.
The aim of this study was to determine cancer morbidity amongst Swedish iron foundry workers with special reference to quartz exposure. In addition to respirable dust and quartz, phenol, formaldehyde, furfuryl alcohols, polycyclic aromatic hydrocarbons (PAHs), carbon black, isocyanates and asbestos are used or generated by foundry production techniques and exposure to any of these substances could have potentially carcinogenic effects.
Cancer morbidity between 1958 and 2004 was evaluated in a cohort of 3,045 male foundry workers employed for >1 year between 1913 and 2005. Standardised incidence ratios (SIRs) with 95 % confidence intervals (95 % CI) were determined by comparing observed numbers of incident cancers with frequencies in the Swedish cancer register. Exposure measures were assessed using information from the personal files of employees and modelling quartz measurement based on a database of 1,667 quartz measurements. Dose responses for lung cancer were determined for duration of employment and cumulative quartz exposure for latency periods >20 years.
Overall cancer morbidity was not increased amongst the foundry workers (SIR 1.00; 95 % CI, 0.90-1.11), but the incidence of lung cancer was significantly elevated (SIR 1.61; 95 % CI, 1.20-2.12). A non-significant negative dose response was determined using external comparison with a latency period of >20 years (SIR 2.05, 1.72 1.26 for the low, medium and high exposure groups), supported by internal comparison data (hazard ratios 1, 1.01, 0.78) for the corresponding groups. For cancers at sites with at least five observed cases and a SIR > 1.25, non-significant risks with SIRs > 1.5 were determined for cancers of the liver, larynx, testis, connective muscle tissue, multiple myeloma plasmacytoma and lymphatic leukaemia.
A significant overall risk of lung cancer was determined, but using external and internal comparison groups could not confirm any dose response at our cumulative quartz dose levels.
Results of follow-up and treatment of different pneumoconiosis types in 749 patients are represented. Rational employment combined with individualized treatment stabilize pneumoconiosis in 80.5% of cases with interstitial silicosis, in those with silico - silicosis --85.5% the nodular form in 70.5% and 77.8% of cases respectively. In the patients with the first symptoms of silicotuberculosisis the interstitial and nodular forms of the process stabilized in more than 50% of cases and in more than 60% of silico - silicatosis cases. Active interstitial tuberculosis was revealed in 7.3% of cases, nodular one--in 16.2%. The course of the macronodular pneumoconiosis in 50.2% of cases was unfavourable. 23.2% of patients with pneumoconiosis caused by electric-welding aerosol showed regress of pneumoconiosis in afterdust period.
The aim of this study was to identify important determinants of dust exposure in the Norwegian silicon carbide (SiC) industry and to suggest possible control measures.
Exposure to total dust, respirable dust, quartz, cristobalite, SiC, and fiber was assessed in three Norwegian SiC plants together with information on potential determinants of exposure. Mixed-effect models were constructed with natural log-transformed exposure as the dependent variable.
The exposure assessment resulted in about 700 measurements of each of the sampled agents. Geometric mean (GM) exposure for total dust, respirable dust, fibers, and SiC for all workers was 1.6mg m(-3) [geometric standard deviation (GSD) = 3.2], 0.30mg m(-3) (GSD = 2.5), 0.033 fibers cm(-3) (GSD = 5.2), and 0.069mg m(-3) (GSD = 3.1), respectively. Due to a large portion of quartz and cristobalite measurements below the limit of detection in the processing and maintenance departments (>58%), GM for all workers was not calculated. Work in the furnace department was associated with the highest exposure to fibers, quartz, and cristobalite, while work in the processing department was associated with the highest total dust, respirable dust, and SiC exposure. Job group was a strong determinant of exposure for all agents, explaining 43-82% of the between-worker variance. Determinants associated with increased exposure in the furnace department were location of the sorting area inside the furnace hall, cleaning tasks, building and filling furnaces, and manual sorting. Filling and changing pallet boxes were important tasks related to increased exposure to total dust, respirable dust, and SiC in the processing department. For maintenance workers, increased exposure to fibers was associated with maintenance work in the furnace department and increased exposure to SiC was related to maintenance work in the processing department.
Job group was a strong determinant of exposure for all agents. Several tasks were associated with increased exposure, indicating possibilities for exposure control measures. Recommendations for exposure reduction based on this study are (i) to separate the sorting area from the furnace hall, (ii) minimize manual work on furnaces and in the sorting process, (iii) use remote controlled sanders/grinders with ventilated cabins, (iv) use closed systems for filling pallet boxes, and (v) improve cleaning procedures by using methods that minimize dust generation.
BACKGROUND--Dental technician's pneumoconiosis is a dust-induced fibrotic lung disease of fairly recent origin. This study was carried out to estimate its occurrence in Sweden. METHODS--Thirty seven dental technicians in central and south eastern Sweden with at least five years of exposure to dust from cobalt chromium molybdenum (CoCrMo) alloys, identified by postal survey, agreed to undergo chest radiography and assessment of lung function and exposure to inorganic dust. RESULTS--Six subjects (16%; 95% confidence interval 6% to 23%) showed radiological evidence of dental technician's pneumoconiosis. The lung function of the study group was reduced compared with historical reference material. With local exhaust ventilation dust levels were generally low, whereas in dental laboratories without such equipment high levels of dust, particularly cobalt, were found. CONCLUSIONS--Pneumoconiosis may result from exposure to inorganic dust in the manufacturing of CoCrMo-based dental constructions. It is possible to reduce this hazard substantially by local exhaust ventilation.
Several prevalence studies have suggested an association between occupational exposure and respiratory symptoms and asthma, but there has been a lack of incidence studies to verify this. This study examined the incidence of respiratory symptoms and asthma in an 11-year Norwegian community cohort study with 2,819 subjects. Predictors examined were sex, age, educational level, lifetime exposure to quartz, asbestos, and dust or fumes, as well as smoking habits and pack-years. The prevalence of exposure to quartz, asbestos, and dust or fumes was, respectively, 3.7%, 5.0%, and 28.3% at baseline. In those exposed to dust or fumes, the odds ratios (95% confidence intervals) varied between 1.4 (1.1, 1.7) and 2.1 (1.3, 3.2) for developing respiratory symptoms or asthma after adjusting for sex, age, educational level, and smoking. Between 5.7% and 19.3% of the incidence of respiratory symptoms and 14.4% of the incidence of asthma were attributable to dust or fumes exposure after adjustment for sex, age, educational level, and smoking. In conclusion, airborne occupational exposure increases the incidence of respiratory symptoms and asthma, independent of sex, age, educational level, smoking habits, and pack-years.
In this study we have measured exposure levels to quartz in different parts of the slate industry in Alta, Northern Norway. Full shift personal samples were collected from the breathing zones of outdoor and indoor workers in the slate quarries and a slate factory. The quartz content of respirable dust was between 7 and 41%. The slate factory had the lower quartz levels although 41% of total and 73% of respirable samples were above the Norwegian TLV for quartz. The average concentration of total quartz in the slate factory was 0.27 mg/m3 and the average concentration of respirable quartz was 0.12 mg/m3. Outdoor in the quarries the average levels of quartz were 0.58 and 0.13 mg/m3 for total and respirable quartz, respectively. From the beginning of the last decade most of the quarry-workers have built quarry halls to protect themselves against a cold winter climate. Inside in these quarry halls the average levels were 1.74 mg/m3 total quartz and 0.46 mg/m3 respirable quartz. Assessment of historical exposure showed that 32 of totally 45 quarry workers with available exposure history had a lifetime inhaled quartz dose of more than 10 g. There is reason to fear that silicosis will be an increasing problem among quarry workers if efforts to reduce quartz exposure are not put into effect.
The objective of this study was to examine how the consistency of self-reported exposure to dust or gas, asbestos, and quartz varied between subjects with and those without respiratory symptoms and asthma in a Norwegian community sample () in 1987-1988. Exposure characterization obtained in a structured work history interview was used as the "gold standard." The authors also wanted to assess how the exposure-disease relation differed when the exposure was based on self-reported versus interview-obtained data. The prevalence of self-reported exposure to dust or gas, asbestos, and quartz was 28%, 5%, and 4%, respectively. The sensitivity of the self-reported exposure data varied from 21% to 64% and was higher in those with than in those without the respiratory disorders. The specificity varied from 78% to 100% and was lower in those with than in those without the respiratory disorders. The sex-, age-, and smoking-adjusted odds ratios of the respiratory disorders in those with exposure to dust or gas and to asbestos were only slightly reduced when misclassification was taken into account. The corresponding numbers for exposure to quartz were halved and lost their statistical significance when the misclassification was allowed for. In this general population sample, the self-reported occupational, airborne exposure data were differentially misclassified by disease status.