Abstract  Associations between inorganic fiber burdens and job category in the lungs of industrial workers were examined. Lung tissue sections were collected from 21 workers employed in gold, zinc, and copper mining, 18 iron foundry workers, 22 noniron foundry workers, four welders, three sandblasting workers, four construction workers, three technical or professional workers, seven workers in 'miscellaneous trades', 13 former asbestos (1332214) workers with mild asbestosis, and 20 persons from the general population (controls). The tissue samples were digested in aqueous sodium-hypochlorite. After drying, the digests were prepared for analysis for quartz (14808607) and other elements by transmission electron microscopy and energy dispersive spectroscopy. The quartz analyses were also performed by X-ray diffraction analysis. The highest quartz concentrations varied from 0.69 to 3.90 million particles per milligram dry lung tissue (mp/mg) and were found in tissues from the miners, iron foundry, and sandblasting workers. Lung quartz burdens in the workers in the other occupations varied from 0.05 to 0.65mp/mg, the highest concentrations in these groups being found in the welders and technical and professional personnel. The quartz concentrations in the asbestos workers and controls averaged 0.40 and 0.23mp/mg, respectively. High levels of metallic particles were found in the lungs of welders and iron foundry workers, averaging 6.13 and 1.10mp/mg, respectively. The particles consisted primarily of aluminum (7429905), nickel (7440020), manganese (7439965), cadmium (7440439), and chromium (7440473). When stratified according to fiber characteristics, the highest concentrations of long fibers were found in noniron foundry workers and asbestos workers. High concentrations of ferruginous bodies were also found in these groups. The noniron foundry workers had been exposed to ceramic and asbestos fibers. The authors conclude that the composition of the particles found in the lungs of these workers can be explained on the basis of their work histories. The broad range of particle types identified demonstrate the complexity of trying to determine disease origins in these occupational settings.

Abstract  Exposures to potentially confounding chemical and physical agents were estimated as part of a study on the relationship between cancer and chronic exposure to electric and magnetic fields among electrical workers. Confirmed or suspected carcinogen (CSC) exposure estimates for 64 job categories from 1950 through 1990 were presented for the Hydrouebec electrical utility. A list associating 57 tasks and general exposures with exposure to one or more CSC was provided. Interviews of foremen and senior workers identified 24 CSC and 15 surrogate exposures present at the facility. Long term exposure was limited to skin exposure to dielectric oils. Acute inhalation exposure to asbestos (1332214), carbon dust, chromium (7440473), nickel (7440020), and methylene-chloride (75092) and skin exposure to mineral oils, polychlorinated biphenyls (PCB) and sunlight were considered for equipment electricians and mechanics in generation and substation repair and maintenance. Regular dermal exposure to wood preservatives was seen for distribution linemen. Exposures for other trades were considered low or rare. No chronic exposures were found to exceed threshold limit values (TLV). Exposure data on 11 CSCs identified in the OSHA National Health Sampling Results as well as surrogate exposure were summarized. Estimated exposures to CSCs classified by job category and time weighted average inhalation exposure were provided. Exposures to specific agents such as asbestos, dielectric oils and PCBs, diesel and gasoline exhaust, herbicides, soldering and welding fumes, solvent use, paint, and wooden poles and wood treatment, were discussed. Activities involving acute exposure to asbestos included cutting/removing gaskets, installing or removing asbestos wrapping, brake work on vehicles or turbine alternators, and working with asbestos blankets, panels or tiles. Dielectric oils and PCBs were the most common exposures, with 21 trades having regular skin contact. The authors conclude that long term exposure rarely exceeded 25% of the TLV for a CSC.

Abstract  The potential of microscopic characterization of fibrous and environmental particles was discussed with two examples from recent laboratory experience. Examples of the characterization of surface modified asbestos (1332214) particles using conventional secondary ion mass spectroscopy, electron spectroscopic imaging, and electron energy loss spectroscopy were given. The secondary ion images of titanium and titanium-oxide may be used to selectively indicate the contour of the asbestos fiber. The titanium ion images demonstrated that, within the lateral resolution of the ion microprobe, the titanium reacted fairly evenly over the selected area of the chrysotile (12001295) surface and no evidence of any significant build up of localized titanium containing compounds was found. The application of the scanning proton microprobe (SPM) method to characterize the North Sea aerosol was discussed. An attempt was made to quantitatively estimate from field measurements the atmospheric input of heavy metals into the North Sea and to evaluate the nature of the aerosol particles responsible for this flux. By using the scanning proton beam it was possible to reveal elemental distributions within a single aerosol particle structure. Detected total amounts for sulfur (7704349), chlorine (7782505), potassium (7440097), calcium (7440702), titanium (7440326), vanadium (7440622), chromium (7440473), iron (7439896), nickel (7440020), and zinc (7440666) were in the range of 0.01 picograms for zinc to 390 picograms for chlorine.

Abstract  BIOSIS COPYRIGHT: BIOL ABS. A hospital-based, case-control study of 531 male and 144 female matched pairs was conducted in Germany to analyze the role of nonoccupational and occupational risk factors in the etiology of tumors of the lower urinary tract (bladder cancer). Smoking of cigarettes was associated with an odds ratio (OR) of 3.6 for men and 3.2 for women, compared with not smoking and showed a significant dose- and time-response relationship for both sexes. Heavy pipe smoking significantly increased the risk (OR = 1.9 in men), and smoking of cigars did not alter the risk of bladder cancer. Controlling for smoking, a significantly twofold or more increase in risk was found for heavy consumption of coffee in both sexes and for heavy intake of beer in males. Increasing levels of total fluid intake were associated with increasing, smoking-adjusted risks in men. Significant associations were found for chronic infection of the lower urinary tract (OR = 1.8), familial history of bladder cancer (O

Abstract  The purpose of this survey was to evaluate the effects of smoking and occupational exposures on the decline in forced expiratory volume in one second (FEV1), and the presence of airflow limitation (FEV1 x100/forced vital capacity (FVC) being < 65) at follow-up. A random sample of 1,933 men aged 22-54 years in Bergen, Norway, were invited into the survey. Smoking habits and measurements of FEV1 were recorded at the initial survey in 1965-1970 (n = 1,591) and at follow-up in 1988-1990 (n = 951). Past or present self-reported occupational exposures to eleven airborne agents (dusts, gases, vapours and fumes) and measurements of FVC were recorded at follow-up only. The decline in FEV1 was associated (p < 0.001) with age, body height and smoking. Smoking cessation reduced the decline to the level of lifetime nonsmokers. Accelerated decline in FEV1 was observed in subjects exposed to sulphur dioxide gas and to metal fumes. The adjusted decline in FEV1 increased progressively in subjects exposed to increasing numbers of occupational agents (test for trend: p < 0.01). Airflow limitation was observed in 9.5% at follow-up, and increased with age and cigarette consumption. In this community follow-up survey in men, smoking and occupational exposures to sulphur dioxide gas, metal fumes and the numbers of specific agents were found to be important predictors for accelerated decline in FEV1.

Abstract  A study of the prevalence of obstructive lung disease in the general population was conducted. The cohort consisted of 3370 persons living in and around Bergen, Norway. They completed a questionnaire to obtain information on biodemographic characteristics, job history, and any occupational exposures to asbestos (1332214), quartz (14808607), wood dust, chromium (7440473), nickel (7440020), platinum (7440064) fumes, fumes in the aluminum industry, and smoking. A total of 1275 subjects were given a medical examination that included spirometric testing. Of these, 38 had asthma, 65 had chronic obstructive pulmonary disease (COPD), and 52 had forced vital capacity volume and 1 second forced expiratory volume (FEV1) values indicative of airflow limitation (airflow limitation group). In the subjects with asthma, COPD, and airflow limitation, the average decrements in FEV1 were 10, 37, and 40%, respectively. The FEV1 decrements increased with age in subjects with COPD and airflow limitation, but not in those with asthma. The prevalence rates for asthma, COPD, and airflow limitation were estimated to be 2.4, 5.4, and 4.5%, respectively. The prevalence of asthma was not affected by smoking status. The prevalence of COPD and airflow limitation was significantly higher in smokers and persons who lived in urbanized areas. Age and smoking were significant risk factors for COPD and airflow limitation after adjusting for sex. Having a job that involved exposure to one or more of the agents was a significant risk factor for asthma and COPD. COPD was significantly associated with exposure to quartz, dust, chromium, nickel, and platinum fume, and aluminum production, processing, and welding. None of the exposures was significantly associated with airflow limitation. When the analysis was restricted to persons older than 50 years, asbestos and quartz exposures were significantly associated with airflow limitation after adjusting for sex, age, and smoking. The authors conclude that COPD is a common disorder in northwestern European populations. Occupational exposure to certain airborne agents and smoking are significant risk factors.

Abstract  In response to a request from an employee at the Hitachi Magnetics Corporation (SIC-3499), Edmore, Michigan, an evaluation was made of possible hazardous exposures to cobalt (7440484), nickel (7440020), silica (14808607), and asbestos (1332214). The current workforce consisted of 416 hourly workers and 115 salaried employees. The facility produced permanent magnets using five production processes: sintered ALNICO; cast ALNICO; Hicorex Rare Earth Iron; Ceramic (Ferrite Magnets); and Lodex. Six reported episodes of respiratory conditions were noted which was more than ten times the number expected for such industries. The incidence of skin disorders was likewise ten times that expected for this industry. Respirable crystalline silica was identified in dust samples collected at eight of the 18 jobs studied. Exposures in three jobs (sand mixer, furnace operator and a machine molder) were above the OSHA permissible exposure limit and all eight jobs exceeded the ACGIH threshold limit value for crystalline silica exposures of 0.1mg/m3. On each shift the post shift creatinine corrected mean urine cobalt concentrations were higher than preshift values. The authors conclude that a hazard existed from exposure to airborne cobalt, nickel and silica. The authors' recommendations pertaining to respiratory protection and the reduction of exposures are included.

Abstract  A review of epidemiological aspects of malignant mesothelioma was presented. Topics included the historical aspects of malignant mesothelioma cases indicating the first diagnosis to have been made at least as early as 1870; a descriptive epidemiology emphasizing natural history of the disease; diagnostic problems; problems with obtaining information from death certificates and tumor registries; geographic distribution of cases of malignant mesothelioma including reports from different countries, regions, cities, shipyard areas, mining regions, and urban areas; the incidence in males and females; an analytical epidemiology with information drawn from case referent studies, cohort studies, prevalence surveys, evidence of lung burden, and exposure and response studies; the importance of etiologic agents other than asbestos (1332214) such as tobacco, natural mineral fibers, man made mineral fibers, organic fibers, cement, copper (7440508), fiberglass (14808607), nickel (7440020), rubber, and wood; and public health aspects including information on risk estimates and control measures. Studies have indicated that most major cities have similar incidence ratios for malignant mesothelioma with the exception of higher rates being found in ports with large naval shipyards or dockyards, or cities with large asbestos industries. Lower rates were found in agricultural regions. Surveys among persons residing within short distances from chrysotile (12001295) mines in Canada or the United States were negative except for individuals directly or indirectly occupationally exposed. Distinctions between fiber types in terms of health risk and regulations were discussed.

Abstract  IPA COPYRIGHT: ASHP Various methods of sterile filtering and removing pyrogens from infusion and injection solutions using asbestos and asbestos free filters were investigated. Seven filters were evaluated using 7 different test media (dextran, 10%; water; polyethylene glycol 400, 30%; dextrose, 10%; etc). Cellulose, alumina (aluminum oxide), kieselguhr and membrane filters in varying porosities and compositions were studied. The filtration effect of the individual filter layers is shown in comparative tables. At the present time, no universal asbestos free filter is available for filtering all injection solutions.

Abstract  HEEP COPYRIGHT: BIOL ABS. A laborer who worked in a steel mill and in a shipyard developed a nonspecific pulmonary interstitial fibrosis. Postmortem samples of his lung were digested and the inorganic material was extracted and examined using transmission electron microscopy, electron diffraction and electron microprobe analysis. Uncoated asbestos fibers were present (1.4 105/g wet lung) as well as a large number of fly ash particles (6ed during coal combustion, had not previously been reported to be present in human lung tissue. Although the contribution of asbestos to this man's lung disease was uncertain, based on previous studies implicating aluminum silicates in pneumoconiosis, fly ash, an aluminum silicate, may have been a contributing factor.

Abstract  Airway obstruction was measured by spirometry in 296 boilermakers with 15 or more years shipyard exposure to asbestos. Percent of predicted was used to adjust each worker's pulmonary function values for height (mean 174 cm), age (mean 52.5 years) and cigarette smoking (mean 23.3 years). Mean values were significantly (P less than 0.05) below predicted for FVC 4.23 l 94.2% FEV1 3.06 l 89.3%, FEF25-75 2.51 l sec-1 82.3% and FEF75-85 0.574 l sec-1 77.8%. Corresponding values for the 106 men with pulmonary asbestosis (ILO profusion of opacities 1/0 or greater), were below these levels. Those without radiographic signs of asbestosis had intermediate values significantly below predicted. Correlation coefficients for pulmonary functions with ILO categories of asbestosis (profusion of irregular opacities) were: FVC -0.2381, FEV1 -0.2494, FEF25-75 -0.2403 and FEF75-85 -0.1629. All were significant P less than 0.05. The subgroup with radiographic asbestosis (ILO 1/0 or greater), had more functional loss. Data on this large cohort of asbestos-exposed workers establish that airway obstruction occurs after 15 years of exposure and before the slightest profusion of asbestosis scarring in the lungs of shipyard workers, and worsens progressively with greater profusions of irregular opacities.

Abstract  Clinical and radiological lung changes from asbestos (1332214) exposure were investigated in humans. Three groups of subjects who worked in buildings with insufficient protection against asbestos were examined clinically, functionally, and radiologically. Group 1, consisting of 160 subjects, worked directly in contact with asbestos sources; group 2, consisting of 277 subjects, worked at least 10 years in the building, but had no specific exposure; and group 3, consisting of 157 subjects, were comparisons who were exposed only during the construction period of the buildings. No differences in the three groups were observed on clinical examination of lymph nodes, rales, abnormal heart sounds, and tenderness of masses on palpation. Functional examinations showed group 1 was significantly higher than the other groups in cough, sputum, and breathlessness; groups 1 and 2 had significantly more chest pain. Radiologically, group 1 had significantly more diaphragmatic straightness, 12 percent as compared to 6 percent for groups 2 and 3. The average mean number of radiological abnormalities was significantly higher in group 1 than group 2 or 3. Possible confounding factors showed that smoking was more frequent in groups 1 and 3; previous tuberculosis and bronchitis were less frequent in group 1 and obesity was significantly higher in group 1. Possible past exposure was highest in group 1.

Abstract  During a repair and reconstruction project of an unpaved highway in a remote region of Alaska, workers discovered, after construction had commenced, that the materials used from a local material site contained asbestos (variously described as tremolite or actinolite). The regional geology indicated the presence of ultramafic rock, which often contains asbestos. Evaluation of asbestos exposure to workers, their equipment, and living quarters was required, as was the possible future exposure of workers and the general public to asbestos already used in the roadway construction. In addition, a decision was needed on whether to use materials from the contaminated site in the future. Of the almost 700 breathing zone air monitoring samples taken of the workers, 3% of the samples indicated exposures at or near 0.1 f/cc by the National Institute for Occupational Safety and Health (NIOSH) 7400 phase contrast microscopy (PCM) procedure. Thirty-six of the PCM samples underwent transmission electron microscopy (TEM) analysis by the NIOSH 7402 procedure, which indicated that about 40% of the fibers were asbestos. After classifying samples by tasks performed by workers, analysis indicated that workers, such as road grader operators who ground or spread materials, had the highest exposures. Also, monitoring results indicated motorist exposure to be much less than 0.1 f/cc. The design phase of any proposed construction project in regions that contain ultramafic rock must consider the possibility of amphibole contamination of roadway materials, and budget for exploration and asbestos analysis of likely materials sites.

Abstract  The potential for fiber exposure during historical use of chrysotile-containing joint compounds (JCC) has been documented, but the published data are of limited use for reconstructing exposures and assessing worker risk. Consequently, fiber concentration distributions for workers sanding JCC were independently derived by applying a recently developed model based on published dust measurements from sanding modern-day (asbestos-free) joint compound and compared to fiber concentration distributions based on limited historical measurements. This new procedure relies on factors that account for (i) differences in emission rates between modern-day and JCC and (ii) the number of fibers (quantified by phase contrast microscopy [PCM]) per mass of dust generated by sanding JCC, as determined in a bench-scale chamber study using a recreated JCC, that convert respirable dust concentrations to fiber concentrations. Airborne respirable PCM-fiber concentration medians (and 95% confidence intervals) derived for output variables using the new procedure were 0.26 (0.039, 1.7) f/cm(3) and 0.078 (0.013, 0.47) f/cm(3) , and corresponding total fiber concentrations were 1.2 (0.17, 9.2) f/cm(3) and 0.37 (0.056, 2.5) f/cm(3) , in enclosed and nonenclosed environments, respectively. Corresponding estimates of respirable and total PCM fiber concentrations measured historically during sanding of asbestos-containing joint compound-adjusted for differences between peak and time-weighted average (TWA) concentrations and documented analytical preparation and sampling artifacts-were 0.15 (0.019, 0.95) f/cm(3) and 0.86 (0.11, 5.4) f/cm(3) , respectively. The PCM-fiber concentration distributions estimated using the new procedure bound the distribution estimated from adjusted TWA historical fiber measurements, suggesting reasonable consistency of these estimates taking into account uncertainties addressed in this study.

Abstract  OBJECTIVES: Few studies have focused on pleural mesothelioma and environmental exposure in individuals residing around an industrial source of asbestos. The aim of this study is to determine whether residential distance and wind conditions are related to the risk of developing pleural mesothelioma.

METHODS: In this retrospective cohort study carried out in an area of Barcelona province (Catalonia, Spain), 24 environmental pleural mesothelioma cases were diagnosed between 2000 and 2009. We calculated the age-standardised incidence rate ratios of developing this disease in the population studied, taking into account the residential distance from the plant. For cases living within a 500-m radius of the plant, the geographical location in relation to the factory was also assessed.

RESULTS: The incidence rate of environmental pleural mesothelioma was higher in the population living within 500 m of the plant than in those living in a radius of 500-2000 m and much higher than those living at 2000-10 000 m. The highest incidence rate ratio for pleural mesothelioma (161.9) was found in the southeast quadrant of the 500-m area, coinciding with the predominant wind direction.

CONCLUSIONS: Residential distance from an industrial source of asbestos and local wind conditions have a considerable impact on the risk of developing environmental pleural mesothelioma.

Abstract  Estimating the burden of exposure-related diffuse lung disease in terms of health effects and economic burden remains challenging. Labor statistics are inadequate to define the scope of the problem, and few studies have analyzed the prevalence of exposure-related illnesses and the subsequent health care cost. Well-defined exposures, such as those associated with coal mines, asbestos mines, and stonecutting, have led to more accurate assessment of prevalence and cost. As governmental regulation of workplace exposure has increased, the prevalence of diseases Such as sillcosis and coal workers' prieurnocomosis has diminished. However, the health and economic effects of diseases with long latency periods, such as asbestosis and rnesothelioma, continue to increase in the short term. Newer exposures, such as those related to air Pollution, nylon flock, and the World Trade Center collapse, have added to these costs. As a result, estimates of cost for occupational diseases, including respiratory illnesses, exceed $26 billion annually, and the true econornic burden is likely much higher.

Abstract  OBJECTIVE: To report the high incidence of lung cancer (LC) and malignant mesothelioma (MM) linked to environmental exposure to erionite fibres in a rural village of central Mexico.

METHODS: This is a retrospective survey of clinical and mortality records from the years 2000-2012, accompanied by an environmental survey for nine Group-1 lung and pleura carcinogenic agents listed by the International Agency for Research on Cancer (IARC).

RESULTS: Out of a total of 45 deaths between 2000 and 2012, 14 deaths correspond to different neoplasms of the lung, and at least four deaths to MM. The ages at diagnosis of MM were between 30 and 54 years. Annual age-standardised mortality rates per thousand due to LC and MM in the village (age >20 years) are 7.09 and 2.48 for males, and 4.75 and 1.05 for females, respectively. Erionite fibres were found in exposed rocks and soils, which can easily become airborne and be carried into streets and recreational areas near schools and homes. Other carcinogenic elements and minerals are found only in trace amounts, except for quartz dust and asbestos (chrysotile) cement sheeting, which are also present in the neighbouring villages.

CONCLUSIONS: These results indicate that environmental exposure to erionite is the main cause of the high rates of MM mortality in the Village of Tierra Blanca, supporting previous similar reports for people exposed to erionite fibres in villages in Turkey.

Abstract  Evidence is presented showing that mesotheliomas can have causes other than exposure to asbestos dust, in both experimental animals and humans. In experimental animals, for example, results from two major experimental laboratories suggest that at least 10% may be taken for background incidence, whereas a third laboratory suggests that the experimental group must have a rate exceeding 30% "Background" also includes mesotheliomas found in association with nonfibrous and fibrous nonasbestiform agents. Mesotheliomas in humans can be broadly classified in a manner similar to those of experimental animals: (1) spontaneously occurring, (2) those with a latent period less than 10 years, (3) childhood mesotheliomas, (4) familial cases, (5) cases before the 20th century, (6) mineralogically negative mesotheliomas, and (7) mesotheliomas caused by nonasbestiform agents. The importance of the acceptance of these "background" cases lies in the fact that a basis is provided for the study of the incidence of disease associated with various types of asbestos.

Abstract  NLRs are members of the PRR family that sense microbial pathogens and mediate host innate immune responses to infection. Certain NLRs can assemble into a multiprotein complex called the inflammasome, which activates casapse-1 required for the cleavage of immature forms of IL-1β and IL-18 into active, mature cytokines. The inflammasome is activated by conserved, exogenous molecules from microbes and nonmicrobial molecules, such as asbestos, alum, or silica, as well as by endogenous danger signals, such as ATP, amyloid-β, and sodium urate crystals. Activation of the inflammasome is a critical event triggering IL-1-driven inflammation and is central to the pathology of autoinflammatory diseases, such as gout and MWS. Recent studies have also shown IL-1 or IL-18, in synergy with IL-23, can promote IL-17-prduction from Th17 cells and γδ T cells, and this process can be regulated by autophagy. IL-1-driven IL-17 production plays a critical role in host protective immunity to infection with fungi, bacteria, and certain viruses. However, Th17 cells and IL-17-seceting γδ T cells, activated by inflammasome-derived IL-1 or IL-18, have major pathogenic roles in many autoimmune diseases. Consequently, inflammasomes are now major drug targets for many autoimmune and chronic inflammatory diseases, as well as autoinflammatory diseases.

Abstract  Introduction: Among the driver gene mutations in non-small-cell lung cancer, mutations in epidermal growth factor receptor (EGFR) are the most important because of their predictive role in selecting patients eligible for targeted therapy. Our aim was to study EGFR mutations in a Finnish non-small-cell lung cancer cohort of 528 patients.

Methods: Mutation testing was conducted on DNA extracted from paraffin-embedded, formalin-fixed tumor material using the following real-time polymerase chain reaction-based kits: Therascreen EGFR PCR Kit and cobas EGFR Mutation Test.

Results: EGFR mutation frequency was 11.4% and all positive cases were adenocarcinomas, of which a majority had an acinar predominant pattern. Mutations were seen significantly more often in females and never-smokers than in males and smokers. The most frequent mutations were L858R in exon 21 and deletions in exon 19. Overall survival of the patients, not treated with EGFR inhibitor, did not differ between EGFR mutation-positive and EGFR mutation-negative patients.

Conclusion: EGFR mutation profile in this Finnish non-small-cell lung cancer cohort resembles in many respect with that of other Western European cohorts, even though the overall frequency of mutations is slightly higher. We show the occurrence of EGFR mutations in patients with occupational asbestos exposure and also in those diagnosed with chronic obstructive pulmonary disease who have not been often investigated before.

Abstract  BIOSIS COPYRIGHT: BIOL ABS. RRM HUMAN ASTHMA ALLERGEN IRRITANT AUTOMOBILE EXHAUST

Abstract  Using a multi-level asymmetric lung bifurcation model, transport and deposition of ellipsoidal fibers in the human upper airways were analyzed. The first three generations (G0-G3) of the tracheobronchial tree were included in the study. The focus of this research is airflow simulation and fiber motion prediction in the multi-level human airway bifurcation model. The laryngeal jet at the trachea entrance was modeled as an equivalent turbulence generator, and downstream in the lower level of the bronchi a laminar flow model was used. Lagrangian simulation of ellipsoidal fiber transport and deposition was performed where the effects of coupled hydrodynamic drag and torque, shear induced lift, gravitational sedimentation, inertial impaction, turbulence diffusion were included in the analysis. The study showed that the multi-level asymmetric lung bifurcation model was flexible, easy to use, and computationally highly efficient. The particle simulation results showed that the elongated fibers were aligned with the main flow direction most of the time, but occasionally they experienced impulsive rotation along their pathway. The rotational motion was dependent on the fiber geometry and the local flow patterns. Fiber deposition pattern and deposition rate in the human upper airways were evaluated. The simulation results were compared with the experimental data. The equivalent sphere model for fiber transport and deposition was also discussed. (C) 2013 Elsevier Ltd. All rights reserved.

Abstract  In order to investigate the mortality of a cohort of chrysotile asbestos miners in China and evaluate its association with exposure to chrysotile, a fixed cohort of 1932 workers in chrysotile asbestos mine was established in 1981 and followed till June 1, 2010. Information on vital status, cause of death and smoking habits was collected. The workers were divided into two groups according to their exposure status. The exposed group was composed of frontline workers who worked directly on mining or processing asbestos products. The control group consisted of those who were not directly exposed to asbestos in their work. Standardized mortality ratio (SMR) was calculated according to Chinese national death rates. Cox proportional hazards model was applied to estimate the adjusted relative risks of deaths from major causes in exposed and control groups: The results of this study showed that main causes of mortality were malignant neoplasm, cardiovascular disease, cerebrovascular disease and respiratory disease for chrysotile miners. The mortality rate was 939.20 per 100 000 person-years for workers. The SMR for all causes of death was 1.46 in the cohort. Statistically significant mortality excesses were found for lung cancer (SMR=1.51), pulmonary heart disease (SMR=2.70), respiratory disease (SMR=1.93), asbestosis (SMR=9.62), and accident (SMR=1.59). The mortalities from malignant neoplasm, lung cancer, cerebrovascular disease and digestive disease in the exposed group were significantly higher than those in the control group. The findings indicate that chrysotile exposure is a risk factor for lung cancer, respiratory disease, cerebrovascular disease and digestive disease.