Exposure to tremolite asbestos and respiratory health in Swedish dolomite workers

Respirable dust and crystalline silica exposure among different mining sectors in India

Silicosis is one of the major occupational lung diseases among miners worldwide. The objective of this study was to characterize respirable dust and crystalline silica from limestone, iron, and bauxite mines in India. In total, 86 personal dust samples were collected from limestone (n = 30), iron (n = 30), and bauxite (n = 26) mines using dust sampler. The concentration of crystalline silica was analyzed using FTIR spectroscopy. Geometric mean respirable dust concentrations observed were 0.92, 1.08, and 1.07 mg/m³ for limestone, iron, and bauxite mines respectively, similarly for crystalline silica concentration observations were 0.015, 0.012 and 0.008 mg/m³ respectively. Among the three studied ores, mean crystalline silica concentration was statistically significant (p < 0.05) using an analysis of variance test. Although the detected levels of exposure are within the Indian exposure limits, attention should be paid to lower crystalline silica levels to minimize the risk of silicosis.

Blue-collar work and women's health: A systematic review of the evidence from 1990 to 2015

Despite the implications of gender and sex differences for health risks associated with blue-collar work, adverse health outcomes among blue-collar workers has been most frequently studied among men. The present study provides a "state-of-the-field" systematic review of the empiric evidence published on blue-collar women's health. We systematically reviewed literature related to the health of blue-collar women published between January 1, 1990 and December 31, 2015. We limited our review to peer-reviewed studies published in the English language on the health or health behaviors of women who were presently working or had previously worked in a blue-collar job. Studies were eligible for inclusion regardless of the number, age, or geographic region of blue-collar women in the study sample. We retained 177 studies that considered a wide range of health outcomes in study populations from 40 different countries. Overall, these studies suggested inferior health among female blue-collar workers as compared with either blue-collar males or other women. However, we noted several methodological limitations in addition to heterogeneity in study context and design, which inhibited comparison of results across publications. Methodological limitations of the extant literature, alongside the rapidly changing nature of women in the workplace, motivate further study on the health of blue-collar women. Efforts to identify specific mechanisms by which blue-collar work predisposes women to adverse health may be particularly valuable in informing future workplace-based and policy-level interventions.

Biopersistent granular dust and chronic obstructive pulmonary disease: a systematic review and meta-analysis

Objective

Applying a systematic review to identify studies eligible for meta-analysis of the association between occupational exposure to inorganic dust and the development of chronic obstructive pulmonary disease (COPD), and conducting a meta-analysis.

Data Sources

Searches of PubMed and Embase for the time period 1970–2010 yielded 257 cross-sectional and longitudinal studies on people exposed to inorganic dust at the workplace with data on lung function. These studies were independently abstracted and evaluated by two authors; any disagreement was resolved by a third reviewer. Of 55 publications accepted for meta-analysis, 27 investigated the effects of occupational exposure to biopersistent granular dust (bg-dust).

Methods

A random effects meta-analysis allowed us to provide an estimate of the average exposure effect on spirometric parameters presented in forest plots. Between-study heterogeneity was assessed by using I² statistics, with I²>25% indicating significant heterogeneity. Publication bias was investigated by visual inspection of funnel plots. The influence of individual studies was assessed by dropping the respective study before pooling study-specific estimates.

Results

The mean FEV1 of workers exposed to bg-dust was 160 ml lower or 5.7% less than predicted compared to workers with no/low exposure. The risk of an obstructive airway disease—defined as FEV1/FVC < 70%—increased by 7% per 1 mg· m^-3 respirable bg-dust.

Conclusion

Occupational inhalative exposure to bg-dust was associated with a statistically significant decreased FEV1 and FEV1/FVC revealing airway obstruction consistent with COPD.

Respiratory disorders associated with heavy inhalation exposure to dolomite dust

BACKGROUND

Although dolomite is classified as a relatively non-toxic, nuisance dust, little information exists as to its potential to produce respiratory disorders following occupational exposure. The purpose of this study was, therefore, to evaluate the possible effects, if any, of heavy inhalation exposure to this chemical on the prevalence of respiratory symptoms, functional impairments and radiographic abnormalities of the lungs.

METHODS

The study population consisted of a group of 39 exposed subjects engaged in digging and excavating activities that were in operation for building a local dam, as well as 40 healthy non-exposed employees that served as the referent group. Subjects were interviewed and respiratory symptoms questionnaires, as suggested by the American Thoracic Society (ATS), were completed for them. Thereafter, they underwent chest X-ray and lung function tests. Additionally, using routine gravimetric techniques, personal dust monitoring for airborne inhalable and respirable dust was carried out at different dusty work sites. Finally to determine the chemical composition of the dust, it was analyzed by X-ray fluorescence (XRF) technique.

RESULTS

XRF revealed that the major component (50.52%) of the dust was calcium magnesium carbonate, dolomite. Additionally, levels of exposure to inhalable and respirable dust were estimated to be 51.7±24.31 and 23.0±18.11mg/m3, respectively. Statistical analysis of the data showed that symptoms such as regular cough, phlegm, wheezing, productive cough and shortness of breath were significantly (p<0.05) more prevalent among exposed workers. Similarly, the ratio of FEV1/FVC in exposed subjects was significantly different from that of non-exposed individuals. In contrast, no significant abnormalities were observed in the chest radiographs of both groups.

CONCLUSIONS

In conclusion, while these data cast doubt on the notion that dolomite is a harmless chemical, they provide evidence in favour of the proposition that exposure to high atmospheric concentrations of this compound is likely to be associated with respiratory symptoms.

Airborne concentrations of chrysotile asbestos in serpentine quarries and stone processing facilities in Valmalenco, Italy

Asbestos may be naturally present in rocks and soils. In some cases, there is the possibility of releasing asbestos fibres into the atmosphere from the rock or soil, subsequently exposing workers and the general population, which can lead to an increased risk of developing asbestos-related diseases. In the present study, air contaminated with asbestos fibres released from serpentinites was investigated in occupational settings (quarries and processing factories) and in the environment close to working facilities and at urban sites. The only naturally occurrence of asbestos found in Valmalenco area was chrysotile; amphibole fibres were never detected. An experimental cut-off diameter of 0.25 μm was established for distinguishing between Valmalenco chrysotile and antigorite single fibres using selected area electron diffraction analyses. Air contamination from chrysotile fibres in the examined occupational settings was site-dependent as the degree of asbestos contamination of Valmalenco serpentinites is highly variable from place to place. Block cutting of massive serpentinites with multiple blades or discs and drilling at the quarry sites that had the highest levels of asbestos contamination generated the highest exposures to (i.e. over the occupational exposure limits) asbestos. Conversely, working activities on foliated serpentinites produced airborne chrysotile concentrations comparable with ambient levels. Environmental chrysotile concentrations were always below the Italian limit for life environments (0.002 f ml(-1)), except for one sample collected at a quarry property boundary. The present exposure assessment study should encourage the development of an effective and concordant policy for proper use of asbestos-bearing rocks and soils as well as for the protection of public health.

Cancer mortality and incidence in cement industry workers in Korea

OBJECTIVES

Cement contains hexavalent chromium, which is a human carcinogen. However, its effect on cancer seems inconclusive in epidemiologic studies. The aim of this retrospective cohort study was to elucidate the association between dust exposure in the cement industry and cancer occurrence.

METHODS

The cohorts consisted of male workers in 6 Portland cement factories in Korea. Study subjects were classified into five groups by job: quarry, production, maintenance, laboratory, and office work. Cancer mortality and incidence in workers were observed from 1992 to 2007 and 1997-2005, respectively. Standardized mortality ratios and standardized incidence ratios were calculated according to the five job classifications.

RESULTS

There was an increased standardized incidence ratio for stomach cancer of 1.56 (27/17.36, 95% confidence interval: 1.02-2.26) in production workers. The standardized mortality ratio for lung cancer increased in production workers. However, was not statistically significant.

CONCLUSION

Our result suggests a potential association between cement exposure and stomach cancer. Hexavalent chromium contained in cement might be a causative carcinogen.

Chronic respiratory symptoms among workers at a limestone factory in Zambia

Limestone processing is a global industry, but few studies have assessed respiratory health among limestone workers. At a limestone factory in Zambia, the authors studied 70 high-exposed workers from the production department, 40 medium-exposed from engineering, and 30 low-exposed from administration. A modified British Medical Research Council respiratory questionnaire was used for recording chronic respiratory symptoms. The prevalence of symptoms was highest among the production workers. After adjusting for age, smoking, previous jobs, and past respiratory diseases, the production workers still had a significantly increased relative risk for cough day and night, cough 4 to 6 times daily in a month, and cough with sputum. The results indicate that exposure to limestone dust is associated with increased prevalence of respiratory symptoms. Until newer technology is installed, proper use of personal protective equipments should be emphasized.

Nuclear anomalies in the buccal cells of calcite factory workers

The micronucleus (MN) assay on exfoliated buccal cells is a useful and minimally invasive method for monitoring genetic damage in humans. To determine the genotoxic effects of calcite dust that forms during processing, MN assay was carried out in exfoliated buccal cells of 50 (25 smokers and 25 non-smokers) calcite factory workers and 50 (25 smokers and 25 non-smokers) age- and sex-matched control subjects. Frequencies of nuclear abnormalities (NA) other than micronuclei, such as binucleates, karyorrhexis, karyolysis and 'broken eggs', were also evaluated. Micronuclei and the other aforementioned anomalies were analysed by two way analysis of covariance. The linear correlations between the types of micronucleus and nuclear abnormalities were determined by Spearman's Rho. There was a positive correlation between micronuclei and other types of nuclear abnormalities in accordance with the Spearman's Rho test. Results showed statistically significant difference between calcite fabric workers and control groups. MN and NA frequencies in calcite fabric workers were significantly higher than those in control groups (p < 0.05). The results of this study indicate that calcite fabric workers are under risk of significant cytogenetic damage.

Respiratory health in Turkish asbestos cement workers: the role of environmental exposure

AIM

Benign and malignant pleural and lung diseases due to environmental asbestos exposure constitute an important health problem in Turkey. The country has widespread natural deposits of asbestos in rural parts of central and eastern regions. Few data exists about the respiratory health effects of occupational asbestos exposure in Turkey. A cross-sectional study was conducted to investigate respiratory health effects of occupational asbestos exposure and the contribution of environmental asbestos exposure.

METHODS

Investigations included asbestos dust measurements in the workplace and application of an interviewer-administered questionnaire, a standard posteroanterior chest X-ray and spirometry. Information on birthplace of the workers was obtained in 406 workers and used to identify environmental exposure to asbestos, through a map of geographic locations with known asbestos exposure.

RESULTS

Asbestos dust concentration in the ambient air of the work sites (fiber/ml) ranged between 0.2 and 0.76 (mean: 0.25, median: 0.22). Environmental exposure to asbestos was determined in 24.4% of the workers. After the adjustment for age, smoking, occupational asbestos exposure, and potential risk factors environmental asbestos exposure was associated with small irregular opacities grade > or = 1/0 (44.2% vs. 26.6%, P < 0.01), FVC% (97.8 vs. 104.5, P < 0.0001), and FEV1% (92.4 vs. 99.9, P < .0001). Occupational exposure to asbestos was associated with small irregular opacities grade > or = 1/0 (OR: 2.0, 95% CI: 1.3-3.1, per 1 unit increase in the natural logarithm of fiber/ml) and FEV1/FVC% (beta: 1.1, SEM: 0.54; P < 0.05, per 1 unit increase in the natural logarithm of fiber/ml).

CONCLUSIONS

Environmental exposure to asbestos could increase the risk of asbestosis and lung function impairment in workers occupationally exposed to asbestos, independent from occupational exposure and smoking.

Chronic obstructive lung diseases and occupational exposure

The scope of this review is to highlight important and interesting articles in the field of the epidemiology of chronic obstructive pulmonary disease and occupational exposure. Relevant information from the literature published within the past year, either on general population samples or on workplaces, indicates that a substantial proportion of asthma and chronic obstructive pulmonary diseases are work related. Methods of investigation include self-reported or interview-obtained questionnaires, job title and job exposure matrix, as well as voluntary or mandatory notifications. Furthermore, data on lung function and immunological tests are available. Specific settings and agents are quoted that have been indicated or confirmed as being linked to chronic obstructive pulmonary disease. In conclusion, occupational exposure to dusts, chemicals and gases will be considered an established, or supported by good evidence, risk factor for chronic obstructive pulmonary disease. The implications of this substantial occupational contribution to asthma and chronic obstructive pulmonary disease must be considered in research planning, in public policy decision-making, and in clinical practice.