Occupational Pneumoconiosis Research Articles

Epidemiological analysis of pneumoconiosis in the Xinjiang Uygur Autonomous Region and cases reported by the Urumqi Railway Bureau.

This study investigated the incidence and development of pneumoconiosis in the Xinjiang Uygur Autonomous Region and cases reported by the Urumqi Railway Bureau to provide a scientific basis for developing prevention and control measures against pneumoconiosis. Data from pneumoconiosis cases were input into Excel and analyzed by SPSS version 17.0. There were 13,165 cases of pneumoconiosis through 2010. Coal workers accounted for the largest proportion of cases. From July 2006 through 2010, a total of 1233 new cases of pneumoconiosis were reported in the Xinjiang Uygur Autonomous Region; most cases were reported in Urumqi. From 1981 to 2012, 3332 new cases of pneumoconiosis had been confirmed by the Urumqi Railway Bureau, including 77.73, 16.96, and 5.31% stage I, II, and III cases, respectively. In the last 30 years, the number of new pneumoconiosis cases peaked in 1986; most of them were silicosis cases. In addition, there were more than 200 cases of pneumoconiosis combined with pulmonary tuberculosis reported by the Urumqi Railway Bureau. The coal industry in Urumqi is the main industry in which occupational pneumoconiosis occurs in Xinjiang. Thus, substantial effort is still required to eliminate pneumoconiosis by 2030.

English

BACKGROUND: Occupation exposes an individual to certain hazards which are known as occupational diseases or pneumoconiosis. Carpet weavers are constantly exposed to dust in their workplace environment, posing a threat to their health. Spirometry is a readily available tool to measure pulmonary functions in the high risk group at an early stage which helps to take necessary measures to prevent further damage. AIMS: To study and compare the effects of long term dust exposure on pulmonary functions of carpet weavers with those of healthy subjects unexposed to such dust. MATERIALS AND METHODS: 50 adult female workers from carpet making industry were chosen for our study. 50 age and sex matched healthy subjects who were not exposed to excessive dust, enrolled as the controls. Forced expiratory spirograms were recorded by RMS Medspiror. Parameters such as forced vital capacity (FVC), forced expiratory volume in 1st second (FEV1), the ratio of FEV1/FVC, forced expiratory flow in the middle half of FVC (FEF25-75%), peak expiratory flow rate (PEFR) were assessed in both cases and controls. STATISTICAL ANALYSIS: The results were analyzed by using the student's unpaired t-test. RESULTS: Carpet weavers showed deterioration in FVC, FEV1, FEF25-75%, PEFR and FEV1/FVC ratio which was statistically highly significant (P< 0.001), suggestive of obstructive respiratory disorder. CONCLUSION: Weavers are at risk of developing occupational lung disease which can be prevented by taking meticulous measures and

A study of GM (1, 1) model for predicting the incidence trends of pneumoconiosis cases of an area

To explore the application of the gray series model GM (1, 1) in predicting trends in the incidence of pneumoconiosis and evaluate its degree of predicted precision. Analyzing the incidence of pneumoconiosis in this region from 2009 to 2013, and predicting the incidence of pneumoconiosis of the area in 2014-2016 by establishing GM (1, 1) according to the gray system theory. Using occupational pneumoconiosis population data from 2009 to 2013, to establish GM (1, 1) model: yt = 1396.89e(0.12(t-1)), α = -0.12, µ = 147.2. The pneumoconiosis in 2014, 2015, 2016 were predicted respectively 51, 47, 43 cases based on the GM (1, 1) model, and C value of model is 0.15, P value is 1, all of them meet the requirements of model predictions. It shows the cases of pneumoconiosis are rising significantly. GM (1, 1) model can be used to predict the recent trend in the incidence of pneumoconiosis.

Consideration of Occupational Lung Disease and Pneumoconiosis in Forensic Pathology

Reports of workers stricken with lung disease sustained during the course of their employment date to antiquity. Despite stringent regulations to mitigate all manners of work place hazards, and the emergence of agencies and physicians engaged in the advancement of occupational health, occupational lung disease remains a significant problem within modern society. Inhalation of dusts and fumes sustained in the course of one's occupation may lead to significant morbidity and mortality, and lead to a huge cost to society in terms of lost productivity, medical care for the worker, and litigation. In certain circumstances, the identification of an underlying occupational lung disease may constitute a significant finding in medicolegal death investigation. This article will present an overview of common occupational diseases likely to be encountered in the practice of forensic pathology, based on the particular etiologic agent and occupational means of exposure.

Severe Occupational Pneumoconiosis Among West Virginian Coal Miners: One Hundred Thirty-eight Cases of Progressive Massive Fibrosis Compensated Between 2000 and 2009

Miners inhale dust at work and are at a risk for coal workers pneumoconiosis (CWP), a preventable and potentially fatal lung disease. After regulations were implemented in the 1970s, declines were reported in both dust levels and the prevalence of simple and advanced CWP until about 2001, when despite stable reported dust levels, disease levels sharply increased. A structured, retrospective chart review was performed to describe the demographics and disease progression for 138 coal miners with progressive massive fibrosis (PMF) whose claims were approved by the West Virginia State Occupational Pneumoconiosis Board between January 2000 and December 2009. PMF, a complication of CWP, developed in 138 West Virginian coal miners at a mean age of 52.6 years after an average of 30 years work tenure. The time of progression averaged 12.2 years from the last normal chest radiograph until PMF was detected. Lung function declined sharply in both smokers and nonsmokers, averaging 87 mL/y for FEV(1) and 74 mL/y for FVC. The board has confirmed 21 deaths in this group. The most common job activities were operating continuous-mining machines (41%) and roof bolting (19%). Virtually all of these miners' dust exposures occurred after the implementation of current federal dust regulations. Contemporary occupational dust exposures have resulted over the past decade in rapidly progressive pneumoconiosis and massive fibrosis in relatively young West Virginian coal miners, leading to important lung dysfunction and premature death.

Health impact of pneumoconiosis in Mongolia: Estimation of losses in life expectancy and quality adjusted life expectancy

To estimate the life expectancy (LE), quality-adjusted life expectancy (QALE), and their losses, in patients with pneumoconiosis in Mongolia. All patients (n = 432) diagnosed with occupational pneumoconiosis during 1986-2006 were recruited from the registry of the National Research Center of Occupational Diseases, which was linked to the National Mortality Registry of Mongolia to obtain the survival function. We simulated age and gender matched referents group based on the life table in 2000. The survival ratio between patients and referents was used to extrapolate and calculate the LE. The average expected years of life loss (EYLL) of pneumoconiosis were calculated as the mean survival difference between patients and referents. We adopted utility values for workers with pneumoconiosis and multiplied them with the survival function to estimate the QALE, which was then used to calculate the loss of QALE. The life expectancy and EYLL of a patient with pneumoconiosis were 18.1 and 9.5 years respectively. QALE and loss of QALE were 15.1 and 12.5 QALYs (quality-adjusted life years), respectively, indicating a health gap of 45%. The health inequality suffered by miners in Mongolia must be addressed through prevention, including exposure monitoring and control, early diagnosis and case management and rehabilitation of pneumoconiosis.

Use of exhaled breath condensate to investigate occupational lung diseases

The present study reviews recent data concerning the assessment of exhaled breath condensate (EBC) pulmonary biomarkers in the field of occupational medicine. EBC is a suitable matrix to assess respiratory health status in workers exposed to pneumotoxic substances, due to its ability to quantify lung tissue dose and consequent pulmonary effects. Published data show that toxic metals and trace elements are detectable in EBC, raising the possibility of using this medium to quantify the lung tissue dose of metals occurring in occupational settings. EBC analysis of biomarkers of exposure highlighted the potential use of EBC as completion of the biological monitoring of pneumotoxic compounds. Different biomarkers of effect, such as oxidative stress and inflammatory-derived biomarkers have been applied in the investigation of occupational asthma and pneumoconiosis, suggesting that the collection of EBC may contribute to studying the pathological state of the airways of workers with acute and chronic exposure to pollutants. EBC measurements also seem to be reliable to detect the presence of carcinogenic processes in the respiratory system, by the analysis of various markers of oxidative stress, angiogenesis and DNA alterations related to lung cancer. This approach may open new frontiers in the study of workers currently or previously exposed to pulmonary carcinogenic agents. The analysis of EBC is one of the most promising methods currently available for the study of pulmonary biomarkers of exposure, effect and susceptibility in occupational settings; being collected in a totally noninvasive way, it is particularly suitable to be applied in field studies and for longitudinal assessments of pulmonary biology.

Cysteine cathepsins and caspases in silicosis

Silicosis is an occupational pneumoconiosis caused by inhalation of crystalline silica. It leads to the formation of fibrohyalin nodes that result in progressive fibrosis. Alternatively, emphysema may occur, with abnormal destruction of collagen fibres in the advanced stages. Although the pathophysiological mechanisms remain unclear, it has been established that the lung responds to silica by massive enrollment of alveolar macrophages, triggering an inflammatory cascade of reactions. An imbalance in the expression of lung proteases and their inhibitors is implicated in extracellular matrix remodelling and basement membrane disruption. Moreover, exposure to silica can initiate apoptotic cell death of macrophages. This review summarises the current knowledge on cysteine cathepsins that have been ignored so far during silicosis and outlines the recent progress on cellular pathways leading to silica-induced caspase activation, which have been partly delineated.

Analysis of the situation of occupational health surveillance and the morbidity of occupational diseases in Guangzhou

To analyze the situation of occupational health surveillance and the characteristics of occupational diseases in Guangzhou. The situation of occupational health surveillance and the morbidity of occupational diseases were studied retrospectively by use of the physical examination data collected from the labour hygienic reports of the city from 1993 to 2002. The data were divided into two groups: the first group from 1993 to 1997, and the second from 1998 to 2002. Annual average of occupational health examination in the past 10 years was over 75%. The data in the second group (1998 - 2002) showed that the number of hearing loss observed subjects, noise surveilled personnels, dust and chemicals contraindicated personnels were significantly higher than those in the 1st group (P < 0.01). The morbidity of chronic occupational disease newly occurred was 91 cases in lst group, and 181 cases in 2nd group (P < 0.05), in which the incidence of chemical poisoning and noise induced hearing loss increased significantly but that of pneumoconiosis between two groups was not significantly different (P > 0.05). In the past 10 years, 581 cases of occupational diseases were diagnosed, of which, 309 cases (53.18%) were acute poisonings, while 272 cases (46.82%) were chronic occupational diseases. Pneumoconiosis, lead and benzene poisoning were common in chronic occupational diseases (16.70%, 16.87% respectively). With the passage of time, the incidence ages of pneumoconiosis, chemical poisoning and total occupational diseases tended towards younger. The difference was statistically significant (P < 0.01) A normal system for occupational health surveillance has been developed in Guangzhou. Detectable rates in focused surveillance and contraindication have been obviously increasing. The incidence of occupational disease (mainly including acute occupational poisoning, pneumoconiosis, lead and benzene poisonings) is also going up. The incidence age of chronic occupational diseases tends to be younger accompanied with a shorter work history.

Mechanism of welding fume suppression during AC-pulsed MIG welding of Al–Mg alloys

Summary Welding fume, inevitably generated during arc welding processes, may be a source of occupational pneumoconiosis when persistently inhaled in the long term and accordingly merits serious consideration in occupational hygiene respects. To improve the working environment at welding sites, it is imperative to ensure total air exchange at work sites, local extraction in the vicinity of welding facilities, and the wearing of respiration protection devices in other respects.1 Currently available preventive measures, however, suffer from a number of drawbacks, such as heavy investments needing to be made in equipment and facilities and operability being obstructed by the wearing of respiration protection devices. Alongside such passive measures, it is desirable to develop welding materials or methods able to suppress welding fume generation at source.

Cancer mortality in women with probable exposure to silica: A death certificate study in 24 states of the U.S.

Background: Silica exposure is known to cause an increased risk of pneumoconiosis and some types of cancers. Exposure to silica is becoming an increasingly common occupational hazard for women. Studies contradict each other on whether or not women suffer more occupational pneumoconiosis than men, but no studies have evaluated cancer risks among women exposed to silica. Methods: Death certificate data on occupation and industry from 24 states in the U.S. between 1984 and 1993 were used to calculate proportional mortality ratios (PMRs) for workers exposed to silica. Results: Over 20,000 deaths (4% of all deaths in persons with possible work-related silica-exposure) occurred among women. The PMR for pneumoconiosis among women working in occupations or industries with possible silica exposure was 13.6 (95% CI: 7.2–23.2), for men 3.8 (CI: 3.7–4.0). Both men and women had higher than expected PMRs for respiratory diseases, lung and esophageal cancers, and external causes of death. In the group with probable silica exposure (both occupation and industry associated with silica), women had elevated PMRs for thyroid cancer (PMR = 5.5), multiple myeloma (PMR = 1.3), digestive organ cancers (PMR = 1.2), whereas men had no increased PMRs for these cancers. Both genders had significantly decreased PMRs for breast cancer, cerebrovascular diseases, nervous system diseases, and brain and other central nervous system cancers. Conclusions: An in depth look at the types of silica exposures (specific work duties) and adjustment for confounders is warranted to determine the importance of these gender-specific excess mortalities associated with possible silica exposure. Am. J. Ind. Med. 36:122–128, 1999. Published 1999 Wiley–Liss, Inc.

Cancer mortality in women with probable exposure to silica: a death certificate study in 24 states of the U.S.

Silica exposure is known to cause an increased risk of pneumoconiosis and some types of cancers. Exposure to silica is becoming an increasingly common occupational hazard for women. Studies contradict each other on whether or not women suffer more occupational pneumoconiosis than men, but no studies have evaluated cancer risks among women exposed to silica. Death certificate data on occupation and industry from 24 states in the U.S. between 1984 and 1993 were used to calculate proportional mortality ratios (PMRs) for workers exposed to silica. Over 20,000 deaths (4% of all deaths in persons with possible work-related silica-exposure) occurred among women. The PMR for pneumoconiosis among women working in occupations or industries with possible silica exposure was 13.6 (95% CI: 7.2-23.2), for men 3.8 (CI: 3.7-4.0). Both men and women had higher than expected PMRs for respiratory diseases, lung and esophageal cancers, and external causes of death. In the group with probable silica exposure (both occupation and industry associated with silica), women had elevated PMRs for thyroid cancer (PMR = 5.5), multiple myeloma (PMR = 1.3), digestive organ cancers (PMR = 1.2), whereas men had no increased PMRs for these cancers. Both genders had significantly decreased PMRs for breast cancer, cerebrovascular diseases, nervous system diseases, and brain and other central nervous system cancers. An in depth look at the types of silica exposures (specific work duties) and adjustment for confounders is warranted to determine the importance of these gender-specific excess mortalities associated with possible silica exposure.

Approaches to assessing pulmonary dysfunction and susceptibility in workers.

Indices of the maximal forced expiration are the most widely adopted method of screening for occupational lung disease because of their ease of measurement, employee acceptability, and reproducibility. However, these indices may lack sensitivity, specificity, or validity in detecting cases of some occupational lung diseases at asymptomatic stages when intervention may affect outcome. In populations at increased risk for occupational asthma, pneumoconiosis, or hypersensitivity pneumonitis, three other types of screening are being evaluated in field settings: tests for bronchial hyperreactivity, barriers to diffusion, and abnormalities in gas distribution in the lung. The potential methods of screening--cold air challenge, methacholine challenge, peak flow logs, diffusing capacity, and single breath nitrogen tests--await clinical trials in industrial settings to evaluate whether early case finding of susceptible subjects can result in prevention of morbidity.

Particles causing lung disease.

The lung has a limited number of patterns of reaction to inhaled particles. The disease observed depends upon the location: conducting airways, terminal bronchioles and alveoli, and upon the nature of inflammation induced: acute, subacute or chronic. Many different agents cause narrowing of conducting airways (asthma) and some of these cause permanent distortion or obliteration of airways as well. Terminal bronchioles appear to be particularly susceptible to particles which cause goblet cell metaplasia, mucous plugging and ultimately peribronchiolar fibrosis. Cancer is the last outcome at the bronchial level and appears to depend upon continuous exposure to or retention of an agent in the airway and failure of the affected cells to be exfoliated which may be due to squamous metaplasia. Alveoli are populated by endothelial cells, Type I or pavement epithelial cells and metabolically active cuboidal Type II cells that produce the lungs specific surfactant, dipalmytol lecithin. Disturbances of surfactant lead to edema in distal lung while laryngeal edema due to anaphylaxis or fumes may produce asphyxia. Physical retention of indigestible particles or retention by immune memory responses may provoke hyaline membranes, stimulate alveolar lipoproteinosis and finally fibrosis. This later exuberant deposition of connective tissue has been best studied in the occupational pneumoconioses especially silicosis and asbestosis. In contrast emphysema a catabolic response, appears frequently to result from leakage or release of lysosomal proteases into the lung during processing of cigarette smoke particles. The insidious and probably most important human lung disease due to particles is bronchiolar obstruction and obliteration, producing progressive impairment of air flow. The responsible particle is the complex combination of poorly digestive lipids and complex carbohydrates with active chemicals which we call cigarette smoke. More research is needed to perfect, correct and quantify our preliminary picture of the pathogenesis of lung disease by particles, but a useful start has been made.

National chronic respiratory disease mortality study: I. Prevalence and severity at death of chronic respiratory diseases in the united states, 1963

The certifiers of 3193 U.S. deaths, aged 35–74, were queried by mail on the presence and severity of several chronic respiratory diseases (excluding tuberculosis, lung cancer and occupational pneumoconioses), in order to evaluate published vital statistics which indicate a marked increase since 1950 in the U.S. death rate from these diseases. The prevalence at death of the chronic respiratory diseases was found to be more than nine tunes greater than its underlying cause death rate. It was also found that U.S. death certifiers in 1963 listed on the death certificates only half of the severe chronic respiratory disease present at death, suggesting that vital statistics based on death certificates may seriously underestimate the contribution of chronic respiratory diseases to U.S. deaths. Such epidemiologic observations on the chronic respiratory diseases as their rapidly increasing U.S. mortality rate, their relatively small contribution to mortality in the U.S. when compared to the U.K., and their relatively high mortality rates in several states could be statistical artifacts arising from variation in habits of death certification.

On the radiological classification of occupational pneumoconiosis according to a Finnish group investigation.

An investigation was made of 309 previously diagnosed cases of occupational pneumoconiosis during the years of 1939–1962. The radiological findings were reclassified according to the ILO Geneva classification (1958). The radiological distribution into various groups was as follows: Z = 13.2 per cent, L = 15.2 per cent, p = 33 per cent, m = 12 per cent, n = 10 per cent and ABC = 7 per cent. No relationship was observed between the duration of exposure and radiological findings. The most important of additional complications, different forms of pulmonary tuberculosis, comprised 27 per cent of the study group.

A Simple Test of Abnormal Ventilation-Perfusion Relationships

A simple test of ventilation-perfusion relationships has been described. This consists in the determination of end expiratory-end tidal pCO 2 difference by means of an infrared CO 2 analyzer. This difference did not exceed 5 mm.Hg in the control group with a residual volume of less than 40 per cent of the total lung capacity. A difference greater than 5 mm.Hg was found in 92 per cent of patients with chronic bronchitis and/or emphysema, in three patients with bronchiectasis and four with category 3 occupational pneumoconiosis. The increased end expiratory-end tidal pCO 2 difference was found to correlate reasonably well with increasing residual volume and decreasing maximum breathing capacity in the bronchitis-emphysema group. Correlation with vital capacity was not as good. It is suggested that the deterimnation of end expiratory-end tidal pCO 2 difference could serve as a rapid screening test for abnormal ventilation-perfusion relationships.

Industrial Health and Disease

A WEEK-END course for medical practitioners on factory medical services and industrial diseases will be held at the London School of Hygiene and Tropical Medicine during October 2-3. The course will be opened by Dr. E. R. A. Merewether, senior medical inspector of factories, and lectures will be given on the clinical approach to industrial medicine, occupational pneumoconioses, anæmia in war-time, nutrition and vitamins in war-time, prevention of industrial dermatitis, and rehabilitation with special reference to minor injuries. The fee for the course is one guinea, which should reach the secretary of the London School of Hygiene and Tropical Medicine, Keppel Street, Gower Street, London, W.I, not later than September 27.