[Analysis of early diagnosis and prevention techniques for occupational pneumoconiosis based on patent perspectives in China's coal industry]

Occupational pneumoconiosis in the coal industry is an occupational disease that seriously endangers coal miners' health. Early diagnosis and prevention techniques are significant in controlling its incidence rate and reducing its harm. This article takes the patent data related to the early diagnosis and prevention of occupational pneumoconiosis in the coal industry, published from 1985 to 2021, as the research object. It uses tools such as the Derwent Data Analyzer (DDA) software, the Patyee Database, and the PatSnap Database to analyze the technological development trend and characteristics in this field from aspects of growth trend, primary patent holders, IPC classification layout, value, and research and development hotspots. The results show that the number of patent applications in this field indicates a rapid growth trend, mainly in the hands of Shandong Energy Group Co. Ltd., Shandong University of Science and Technology, China University of Mining and Technology, and other institutions or enterprises. Patent technology mainly involves spray dust reduction, dust removal fans, dust masks, and other aspects with high patent value and innovation ability. This article provides a new perspective and reference for preventing, diagnosing, and treating occupational pneumoconiosis in the coal industry.

Epidemiology of silicosis reported to the central register of occupational diseases over last 20 years in Poland

OBJECTIVES

The aim of the study was to investigate and assess the incidence of silicosis cases acknowledged as occupational diseases in Poland in 2000-2019.

MATERIAL AND METHODS

The cases of all medically recognized pneumoconioses, including silicoses, certified as occupational diseases were studied. The records were extracted from the Central Register of Occupational Diseases, the only official Polish central electronic data base of occupational diseases.

RESULTS

During the period 2000-2019, 2066 confirmed cases of silicoses and 10 665 cases of other pneumoconioses including asbestosis and coal workers' pneumoconiosis were reported to the Central Register of Occupational Diseases. Silicoses accounted for 12.8-21.2% of all pneumoconioses. The number of confirmed silicoses cases was growing along with the length of latency period and was the highest for the period of ≥40 years (513 cases). Over 70% of silicoses cases occurred after occupational exposure >20 years. The most workers who evolved silicosis were employed in manufacturing, predominantly casting of iron, mining and quarrying and construction.

CONCLUSIONS

The number of confirmed cases of silicosis in Poland decreased in 2000-2019 but the disease still remains an important health problem. Prevention is crucial to reduce further disease incidence. The medical monitoring standards of exposed workers should be improved. Developing new diagnosing guidelines with the use of other imaging examinations, like high-resolution computed tomography, has to be considered. The analysis should contribute into the implementation of silicosis preventative programmes, both at the enterprise and national level. Int J Occup Med Environ Health. 2022;35(5):561-70.

Coal miner participation in a job transfer program designed to prevent progression of pneumoconiosis, United States, 1986-2016

The Part 90 program was designed to prevent progression of pneumoconiosis in U.S. coal miners by establishing their right to transfer to a less dusty job in the mine. We calculated the proportion of Part 90-eligible miners who participated during 1986-2016, examined participation by region, and compared characteristics of miners by participation status. Of the 3,547 eligible miners, 14.4% exercised their Part 90 option. Miners working in states outside central Appalachia, and those with more severe pneumoconiosis, were more likely to participate. The primary goal of respiratory health surveillance of coal miners is early detection of disease so that preventive action can be taken. Future studies should seek to better understand factors influencing Part 90 program participation.

Pneumoconiosis in different sectors and their differences in Turkey

INTRODUCTION

Pneumoconiosis which is one of the ancient diseases, still affects many workers throughout the world despite "existing" control programs. We add data from a single center reviewing risk factors for pneumoconiosis; evaluate functional and radiological findings in different sectors.

MATERIALS AND METHODS

We reviewed medical records of patients diagnosed with pneumoconiosis who were admitted to our center between the years 2013 and 2015. Several personal and occupational features, together with functional and radiologic data, were collected.

RESULT

60 were young males. Twenty-four of the cases (39.3%) worked at dental technician, 24 cases (39.3%) were ceramic workers, 5 cases (8.2%) were sandblasters, 2 cases (3.3%) were welders, 3 cases (4.9%) were miners, and 3 cases (4.9%) were marble cutters. The sectors in which the exposure started at the earliest ages were dental technicians and sandblasters, while the shortest working time was in sandblasting. The dental technicians were younger than the ceramic workers at the age of diagnosis (Kruskall-Wallis p= 0.003). The exposure time of the sandblasters was significantly shorter, especially than the ceramic workers (Kruskall-Wallis p= 0.002). The cases have been referred to us with pneumoconiosis suspicion based on the radiographic findings in the PA chest roentgenogram performed during the periodic examinations at their work place; but unlike other studies, in our study, following the HRCT assessment, cases which did not present any visible pathology in the re-evaluation of their PA chest roentgenogram, but had HRCT findings have been diagnosed as pneumoconiosis. Among the 44 cases in which micro-nodules had been detected at their HRCT, 15 of them had been previously classified as profusion of small opacities 0/1 according to their PA chest roentgenogram findings. It has been seen that the HRCT findings differ among sectors. Ceramics workers and sandblasters had significantly more micro-nodules, while dental technicians had significantly more mediastinal lymphadenopathies (Chi square, p= 0.004 and p= 0.007 respectively). When the relationship between the existence of big opacities and complaints was studied, statistically significant weight loss was detected in cases which had C opacities (chi square p= 0.01). Statistically significant FEV1 decrease was observed in cases which had weight loss (independent samples t-test p= 0.046). It has been observed that when the profusion of small opacities increased, while there was no statistically significant functional status change in non-smokers, a significant functional impairment was observed in smokers.

CONCLUSIONS

Pneumoconiosis still exists in Turkey. Even a short exposure time as 2 years can cause pneumoconiosis. Workers in different sectors had different functional, radiological properties and smoking can affect the diseases' course. There are serious limitations related to the surveillance of both the workplace environment and the employees' health in Turkey. Without institutional preventive measures, personal protection and surveillance examinations, occupational hazards will continue to cause premature deaths. Pneumoconiosis in different sectors is a prototype of uncontrolled industry in the developing world.

[FEDERAL CLINICAL PRACTICE GUIDELINES FOR THE DIAGNOSIS, PREVENTION AND TREATMENT OF PNEUMOCONIOSIS]

The purpose of development of this clinical practice guidelines was to provide evidence-based protocols that help the practitioner and the patient make the right decision for the health assessment, treatment and prevention of pneumoconiosis. Pneumoconiosis is the interstitial lung disease of occupational origin caused by prolonged inhalation of inorganic dust, characterized by chronic diffuse aseptic inflammation in lung tissue with the development of pulmonary fibrosis. Currently, thereare no treatment that provide a cure pulmonary fibrosis and changes in the dynamics of decline in lung function. Regular, individually tailored treatment should be directed to the pathogenic mechanisms and some clinical symptoms of pneumoconiosis, as well as the prevention of complications. To enhance the effect of pharmacotherapy is recommended to use non-drug therapies that enhance the functionality of the respiratory system.

Cost-Effectiveness of Coal Workers' Pneumoconiosis Prevention Based on Its Predicted Incidence within the Datong Coal Mine Group in China

We aimed to estimate the economic losses currently caused by coal workers’ pneumoconiosis (CWP) and, on the basis of these measurements, confirm the economic benefit of preventive measures. Our cohort study included 1,847 patients with CWP and 43,742 coal workers without CWP who were registered in the employment records of the Datong Coal Mine Group. We calculated the cumulative incidence rate of pneumoconiosis using the life-table method. We used the dose-response relationship between cumulative incidence density and cumulative dust exposure to predict the future trend in the incidence of CWP. We calculate the economic loss caused by CWP and economic effectiveness of CWP prevention by a step-wise model. The cumulative incidence rates of CWP in the tunneling, mining, combining, and helping cohorts were 58.7%, 28.1%, 21.7%, and 4.0%, respectively. The cumulative incidence rates increased gradually with increasing cumulative dust exposure (CDE). We predicted 4,300 new CWP cases, assuming the dust concentrations remained at the levels of 2011. If advanced dustproof equipment was adopted, 537 fewer people would be diagnosed with CWP. In all, losses of 1.207 billion Renminbi (RMB, official currency of China) would be prevented and 4,698.8 healthy life years would be gained. Investments in advanced dustproof equipment would be total 843 million RMB, according to our study; the ratio of investment to restored economic losses was 1:1.43. Controlling workplace dust concentrations is critical to reduce the onset of pneumoconiosis and to achieve economic benefits.

[Epidemiological analysis of new cases of pneumoconiosis in Ningxia Hui Autonomous Region, China from 2006 to 2010]

OBJECTIVE

To investigate the epidemiological characteristics of pneumoconiosis in Ningxia Hui Autonomous Region, China from 2006 to 2009.

METHODS

Statistical analysis was performed on the types, populations, ages, and geographic distribution of the pneumoconiosis cases in Ningxia from 2006 to 2010, as reported in China Information System for Diseases Control and Prevention.

RESULTS

A total of 625 new cases of pneumoconiosis (4 death cases) occurred throughout Ningxia from 2006 to 2010. Of the new cases, 538 (86.1%) suffered stage I pneumoconiosis, 70 (11.2%) stage II pneumoconiosis, and 17 (2.72%) stage III pneumoconiosis. Silicosis and coal-workers' pneumoconiosis were the dominant types of pneumoconiosis, accounting for 97.44% (609/625) of all cases. Of the 625 cases, 557 (89.12%) were distributed in Shizuishan City, and 563 (90.08%) were engaged in coal and metallurgical industries. Most cases were in the 35-year-old group and 45-year-old group, and the lengths of dust-exposed service mostly ranged from 10 to 29 years.

CONCLUSION

In Ningxia, pneumoconiosis control should focus in the state-owned, middle-sized coal enterprises in Shizuishan City. Health surveillance should be enhanced in the workers with more than 10 years of dust-exposed service or aged more than 35 years, so as to reduce the incidence of occupational diseases.

How to improve the hygienic quality of forages for horse feeding

BACKGROUND

Improving the hygienic quality of forages for horse nutrition seems to be a reasonable target for decreasing the prevalence of pulmonary diseases. The aim of the experiment was to study the effects of different agricultural practices on the main aero-allergens contained in forages, including breathable dust, fungi, mycotoxins and pollens.

RESULTS

Results showed that the late harvest of hay, a second crop or a haylage production provides a good alternative to increase hygienic quality by reducing fungi contamination and breathable dust content. Barn drying of hay, while having no effect on breathable dust, similarly reduced fungi contamination. In contrast, when hay was harvested at a lower dry mass content (750 g DM kg⁻¹ versus 850 g DM kg⁻¹), both breathable dust and fungi contaminations were increased, which could at least be reversed by adding propionic acid just before baling. Zearalenone was detected in different hays, and even in one case, in breathable dust.

CONCLUSION

Overall, our data suggest that different approaches can be used to increase forage hygienic quality for horse feeding and thus reduce their exposure to factors involved in equine pulmonary disease.

Toxicity of monazite particulates and its attenuation with a complex of bio-protectors

BACKGROUND

Workers employed on mining, processing and storage of monazite are at risk of exposure to dust with expected adverse health effects.

OBJECTIVES

To study the adverse health effects of monazite particles in experiments on rats and to test the possibility of attenuating these effects.

METHODS

Outbred white rats were injected intratracheally with a suspension of ground monazite concentrate (MC) in order to investigate the cellular response of the lower airways 24 hours later and the organism's status 6 months after the injection. The bio-protective complex (BPC) tested in these experiments consisted of glutamate, an iodine preparation, methionine, a polyvitamin-polymineral composition, and/or "Eicosavitol" (fish oil preparation rich in PUFA, predominantly of the omega 3-group). Bio-protectors were administered together with the rat food and drink daily for one month before the MC injection in the short-term experiment, or over 6 months after such injection in the long-term experiment.

RESULTS

MC induced manifestations of its cytotoxicity, fibrogenicity and systemic toxicity as well as genotoxicity. The tested BPC attenuated virtually all these effects. Although a similar protective potential of "Eicosavitol" against almost all of them was lower compared with that of BPC, combining BPC with "Eicosavitol" provided, as a rule, the greatest protective effect.

CONCLUSION

It may be assumed that the many-sided adverse effects of MC on the organism is due, at least partially, to the presence in its composition of not only rare earth elements but also of natural radioisotopes of the thorium and uranium families. The combination of the bio-protectors tested was highly effective and may be recommended for administering in periodic preventive programmes to exposed workers.

[Efficacy of preventive measures for reducing professional disorders due to pumice powder]

The analysis of the incidence of pumice pneumoconiosis in the period 1970-2002 allows to evaluate the positive effects, particularly on the deadly forms of the disease, of the technical interventions aimed at reducing dusts. The main interventions in the field of the workmanship of pumice were made at the beginning of 70s, with the introduction of electrofilters in the working cycle and the change of the pumice desiccation system, from plate ovens to closed-cycle rotating ovens. This eliminated the need for manual shedding of pumice stones on oven plates. That duty had caused, between 70s and 80s, an high incidence of deadly forms of pneumoconiosis, which dramatically decreased with the reduction of workers exposed to the above risk. A comparison between the period 1970-75 (before preventive technical interventions) and the period 1976-2002 clearly shows an evident decrease both of deadly forms of pneumoconiosis and of acceptance of appeals for professional silicosis.

Occupational safety and health objectives of Healthy People 2010: a systematic approach for occupational health nurses--part I

The Healthy People 2010 prevention agenda, along with the nation's leading health indicators, provides employers with national targets regarding safety, health, and disease prevention. The first five safety and health objectives presented in this article target a reduction in work-related deaths, work-related injuries, overexertion or repetitive motion injuries and illnesses, pneumoconiosis deaths, and work-related homicides. Although progress is being made, opportunities exist to make a greater impact. Using the information and strategies discussed, occupational health nurses can play a key role in developing and implementing workplace safety and health promotion programs.

The Mine Safety and Health Administration's criterion threshold value policy increases miners' risk of pneumoconiosis

BACKGROUND

The Mine Safety and Health Administration (MSHA) proposes to issue citations for non-compliance with the exposure limit for respirable coal mine dust when measured exposure exceeds the exposure limit with a "high degree of confidence." This criterion threshold value (CTV) is derived from the sampling and analytical error of the measurement method.

CONCEPTUAL FRAMEWORK

This policy is based on a combination of statistical and legal reasoning: the one-tailed 95% confidence limit of the sampling method, the apparent principle of due process and a standard of proof analogous to "beyond a reasonable doubt."

CRITIQUE

This policy raises the effective exposure limit, it is contrary to the precautionary principle, it is not a fair sharing of the burden of uncertainty, and it employs an inappropriate standard of proof. Its own advisory committee and NIOSH have advised against this policy. For longwall mining sections, it results in a failure to issue citations for approximately 36% of the measured values that exceed the statutory exposure limit.

DISCUSSION

Citations for non-compliance with the respirable dust standard should be issued for any measure exposure that exceeds the exposure limit.

Addition of calcite reduces iron's bioavailability in the Pennsylvania coals--potential use of calcite for the prevention of coal workers' lung diseases

In the present study, a hypothesis was tested that the addition of calcite into the Pennsylvania coals may reduce levels of bioavailable iron (BAI), an important component in the mixed coal dust that may contribute to coal workers' lung diseases. Predetermined proportions of calcite (0, 1, 2, 5, 10% w/w) were added into three PA coals. After suspending the mixtures in an aqueous phosphate solution (10 mM, pH 4.5), which mimics the phagolysosomal conditions of the cells, levels of pH as well as calcium ions (Ca2+) in the coals were increased in a calcite concentration-dependent manner. In contrast, levels of BAI (both Fe2+ and Fe3+) were decreased. The inhibitory effects of calcite on the bioavailability of iron in human lung epithelial A549 cells and primary rat alveolar macrophages (AMs) were also examined. It was found that levels of low-molecular-weight (LMW) iron were significantly decreased in both A549 cells and AMs treated with the 10% calcite-PA coal mixture compared to those treated with the PA coal alone, while calcite itself had no effect on intracellular LMW iron. Calcite also showed a significant inhibitory effect on PA coal-induced ferritin synthesis in A549 cells. Reverse-transcription polymerase chain reaction (RT-PCR) studies revealed that the iron-containing PA coal downregulated levels of transferrin receptor (TfR) mRNA in A549 cells, which was partially restored by the addition of calcite. Our results indicate that calcite can inhibit the bioavailability of iron in the iron-containing PA coals.

Assessment of respirable dust and its free silica contents in different Indian coalmines

Assessment of respirable dust, personal exposures of miners and free silica contents in dust were undertaken to find out the associated risk of coal workers' pneumoconiosis in 9 coal mines of Eastern India during 1988-91. Mine Research Establishment (MRE), 113A Gravimetric Dust Sampler (GDS) and personal samplers (AFC 123), Cassella, London, approved by Director General of Mines Safety (DGMS) were used respectively for monitoring of mine air dust and personal exposures of miners. Fourier Transform Infra-red (FTIR) Spectroscopy determined free silica in respirable dusts. Thermal Conditions like Wet Bulb Globe Temperature (WBGT) index, humidity and wind velocity were also recorded during monitoring. The dust levels in the face return air of both, Board & Pillar (B&P) and Long Wall (LW) mining were found above the permissible level recommended by DGMS, Govt. of India. The drilling, blasting and loading are the major dusty operations in B&P method. Exposures of driller and loader were varied between, 0.81-9.48 mg/m3 and 0.05-9.84 mg/m3 respectively in B&P mining, whereas exposures of DOSCO loader, Shearer operator and Power Support Face Worker were varied between 2.65-9.11 mg/m3, 0.22-10.00 mg/m3 and 0.12-9.32 mg/m3 respectively in LW mining. In open cast mining, compressor and driller operators are the major exposed groups. The percentage silica in respirable dusts found below 5% in all most all the workers except among query loaders and drillers of open cast mines.

[Specific occupational hazards and their health effects among dental technicians]

The authors describe specific hazards occurring at workplaces of dental technicians. Exposure to chemical and biological factors in particular and their health effects are presented in detail. Among chemical factors, a specific danger is associated with allergens (methyl metacrylate, metals, latex, tiurams), which may lead to the development of pneumoconiosis. In the authors' opinion, exposures to biological hazards need an extensive analysis. A thorough, hygiene and epidemiological study of occupational exposure and its health effects among dental technicians in Poland would be also very useful.

Mineral fiber problems and their management: UK 1890-1935

BACKGROUND

The first intimation that mineral fibers other than asbestos were biologically active, is generally identified with reports of experimental studies by Stanton and Wrench, and Pott and Friedrichs, in the early 1970s. In 1890 however, man-made mineral fiber was recognized to present human health hazards; in 1912 experimental study confirmed asbestos to be fibrogenic, and by 1935 other mineral fibers came to notice as potential lung hazards.

METHODS

Published and archival sources have been reviewed to trace the emergence between 1890 and 1935 of the awareness of the health hazards of various fibrous minerals, and the development of strategies for their control.

RESULTS

By the early 1900s there was evidence that the asbestos substituted for the man-made mineral fiber insulation material employed to improve the thermal efficiency of steam powered engines, presented a serious health problem. In the early 1930s, other mineral fibers came to be suspected of causing pneumoconiosis.

CONCLUSIONS

Containment, local exhaust ventilation and personal respiratory protection were instituted for the amelioration of asbestosis, but because of the limitations of what was perceived to be reasonably practicable on economic grounds, and what was feasible technologically, their benefits were severely limited. Initial and periodic medical examination were introduced as precautionary measures, based on hope rather than on experience. When in the early 1930s, the investigation of coal mine dust and siliceous dust, threw up the hypothesis that fibrous natural mineral dusts other than asbestos might be fibrogenic, this was ignored and no further investigations were pursued and no precautionary measures were set in train.

Dust concentrations and respiratory risks in coalminers: key risk estimates from the British Pneumoconiosis Field Research

To help inform the setting of dust control standards in coalmines, this brief review summarises the most recent and reliable exposure-response relations, for damaging respiratory effects, derived from the Pneumoconiosis Field Research (PFR). Collecting data over 38 years in the British coal industry, this was a programme of prospective research on the respiratory health of coal miners, characterised by regular health surveys and detailed measurements of dust and silica concentrations in the workplace. Exposure-response relations are presented for coal workers' simple pneumoconiosis category II, progressive massive fibrosis, defined deficits of lung function (FEV1), and category II silicosis. This simplified overview provides a guide to the most recent and most reliable estimates from the PFR of dust-related risks of substantial pulmonary disease, and to the magnitude of the effects. Control of dust sufficient to prevent category II simple pneumoconiosis should prevent most cases of progressive massive fibrosis and most dust related large lung function deficits. Where the dust contains high proportions of silica, control to low levels is essential, and even quite brief excursions of silica to high levels must be avoided.

Occupational Lung Disease in China

Occupational lung disease has been a major public health problem in China. The recently transformed industrial structure and expansion of the industrial labor force, accompanying the rapid industrialization and economic growth, pose both tremendous challenges and opportunities for occupational health policy and research. New occupational health problems are emerging, while the traditional occupational lung disease continued to occur. Simultaneously, relevant scientific research and professional activities have accelerated notably. The progress and achievement in occupational health research are creating more powerful forces in eliminating industrial hazards and protecting workers' health in China.

The fox guarding the chicken coop: monitoring exposure to respirable coal mine dust, 1969-2000

Following passage of the Coal Mine Health and Safety Act of 1969, underground coal mine operators were required to take air samples in order to monitor compliance with the exposure limit for respirable dust, a task essential for the prevention of pneumoconiosis among coal workers. Miners objected, claiming that having the mine operators perform this task was like "having the fox guard the chicken coop." This article is a historical narrative of mining industry corruption and of efforts to reform the program of monitoring exposure to coal mine dust. Several important themes common to the practice of occupational health are illustrated; most prominently, that employers should not be expected to regulate themselves.

[Analyses of 1003 death cases of pneumoconiosis from Xuzhou coal mines]

In order to investigate the general rules concerning attack, development and death of pneumoconiosis for providing scientific evidences for preventing, 1003 death cases of pneumoconiosis from Xuzhou coal mine factory were analyzed. Results showed that: (1) The death causes was in the sequence of pneumoconiosis, lung tuberculosis, chronic cor pulmonale, pulmonary carcinoma, etc., and changed into pneumoconiosis, chronic cor pulmonale, pulmonary carcinoma, cerebrovascular accident, etc. since 1990s. Lung tuberculosis would no longer be the main death cause of pneumoconiosis; (2) The accumulative death percentage of the death cases about pneumoconiosis was correlated to the length of dust exposure. The accumulative death percentage increased rapidly in a beeline within 5 to 20 years; (3) The length of service of episode and mean life of digging or mining workers were significantly shorter than that of others (P < 0.01); (4) The mean life and the course of diseases became more and more longer than ever since 1970s. Therefore, it can be concluded that the key for preventing and controlling pneumoconiosis was to decrease the concentration of dust in workplace and to limit the length of service of dust exposure.

[Dust exposure in a pottery plant assessed by using GRIMM dust monitor]

In one of the pottery plants in which pneumoconiosis was the only certified occupational disease (16 cases during the years 1984-1997), the concentrations of dust in inhalable, thoracic and respirable fractions were measured at most characteristic workplaces. The highest concentrations in all the three fractions was found in the slip house; the mean concentrations were as follows: inhalable dust-7231.8 mg/m3; thoracic fraction--4834.9 mg/m3; and respirable fraction 1402.2 mg/m3. High concentrations of all the dust fractions were also observed at the workplace of the intershop transport worker who removed the waste body from cast and throw shops. The largest number of pneumoconiosis (7) cases was found among the workers of the slip house (20 persons employed); this was followed by the intershop transport workers-4 cases (4 persons employed). At the other workplaces (cast shop, throw shop and firing), concentrations of inhalable dust ranged from 1175 to 3232 mg/m3; thoracic from 726 to 2001 mg/m3; and respirable from 146 to 549 mg/m3. The contents of free crystalline silica (SiO2) in the air dust ranged from 3% in firing to 50% in slip house, in the latter mostly in the form of quartz or cristobalite. The main fraction of inhalable dust was the tracheobronchial fraction, ranging from 43.1 to 48.2%, the extrathoracic fraction ranged from 32.8 to 42.3% and respirable fraction from 11.8 to 21.6%. On the basis of the graphic record, such activities as pouring of raw materials into grinding mill and reloading of the waste body were identified at the workplaces of slip making and internship transport as those associated with the highest dust emission.

[Activities of the regional occupational health center under present-day conditions]

The authors represented experience of contemporary activities of Occupational center in Rostov region, demonstrated efficiency of thorough medical examinations carried by mobile clinical and diagnostic laboratories, suggested 4-levels structure of occupational service organization.

[Study on the prevention, control and elimination of pneumoconiosis in fluorite mine]

OBJECTIVE

To prevent pneumoconiosis by strengthening comprehensive dust-proof and controlling its pathogenesis, and to discuss feasibility of pneumoconiosis elimination in our country.

METHODS

Comprehensive dust-proof was used for reducing the concentration of dust. Epidemiological investigation of pneumoconiosis was employed for evaluating the efficiency of pneumoconiosis prevention. Prospective tracking investigation was used for identifying the feasibility of the pneumoconiosis elimination.

RESULTS

The outcomes of dynamic observation of 35 years from 1962 to 1996 and results of prospective thirty years tracking investigation showed that after comprehensive dustp-roof, the average dust concentration and time weighted mean dust concentration in workers' operating conditions decreased from 366.0 mg/m3 and 163.4 mg/m3 to 1.2 mg/m3 and 1.3 mg/m3 respectively, and the declined rates reached 99.7% and 92.1%, respectively. After controlling pneumoconiosis pathogensis, the incidence rate of pneumoconiosis, its prevalence rate and mortality rate decreased from 24.8%, 85.5% and 5.9% to zero respectively.

CONCLUSION

The thirty years prospective tracking investigation validated that the incidence of pneumoconiosis was zero. So the goal to eliminate pneumoconiosis was achieved.

From quartz hazard to quartz risk: the coal mines revisited

Following the classification of quartz as a human carcinogen by the IARC, many standard-setting committees are currently trying to convert this hazard into their national or EU standards. Since human data to set a safe exposure limit for quartz are limited, we hypothesized that lung burden data on quartz in coal miners' lungs after lifetime exposure could be used to set a non-carcinogenic lung burden of quartz, and that this might be valid for other groups occupationally exposed to quartz. A review of data shows that lungs of coal miners with simple coal workers' pneumoconiosis (sCWP) typically contain up to 30 g of dust, and in one specific study lung burdens between 0.7 and 1.7 g of quartz were associated with macules only, and no sCWP. Assuming independent actions of coal and quartz and no clearance of quartz, and sCWP as a prerequisite for lung cancer due to quartz exposure in coal mine dust, a simple kinetic approach was applied. A no observed adverse effect level (NOAEL) for quartz of between 0.03 and 0.13 mg/m3 (40 yr exposure) is derived, but it is concluded that more refined physiologically based pharmacokinetic modelling is needed for a better estimate, also including interindividual differences in lung clearance. Considering the independent effects of, and the well-known interaction between coal and quartz, these data could be important to other workplaces with usual mixed-dust exposure.

Disturbance of respiratory system in workers in smelter plants

Workers from smelter plants are at high risk from lung injuries due to exposure to quartz sand, clay, resin, loams, airborne metals etc. The aim of this study was to investigate the relevance of the problem and the risk of occupational pathology in metallurgy at "ELMA" plant--Troyan. The study revealed decreased number of occupational lung diseases but the percentage rate (about 10%) of registered new cases with occupational lung diseases was maintained. No new cases with mixed silicosis were recorded. The results were compared to respective national data. Slowly evolving forms of diffusely outlined lung chart with late functional breathing disturbances were prevailing. Chronic bronchitis are presented as a polyetiologic paraoccupational disease.

The Medical Research Council Pneumoconiosis Research Unit, 1945-1985: a short history and tribute

The Pneumoconiosis Research Unit (PRU) was set up to obtain the information needed to eliminate pneumoconiosis of coal workers. To this end, instruments and procedures were developed for dust sampling, delivering dust to animals, testing lung function, reading chest radiographs, conducting respiratory surveys and extracting the relevant information. A provisional estimate of safe working conditions was made using data from four pits. The National Coal Board extended the research to an additional 20 pits, refined the estimate and applied it nationally. Meanwhile at PRU aspects of treatment were explored, immunological techniques were added to the repertoire of skills, other occupational disorders were highlighted and new information obtained on biological variation in lung function and blood pressure. The work laid the foundations for medical epidemiology and evidence-based medicine. Starting in 1959, the Unit took the lead in a world campaign to control lung diseases due to asbestos. This account indicates how these successes were achieved, what were the failures, some tensions which developed and what might have been if some events had been handled differently. If there is a message, it is that for success in research the problem under consideration should be the prime focus of attention and resources.

[Occupational medicine in aluminum and copper alloy production]

Workers engaged into aluminum alloys production demonstrated high prevalence of occupational respiratory diseases caused by dust--pneumoconiosis and dust bronchitis, workers of copper alloys production were diagnosed as having early stage of chronic lead intoxication.

The past and present of pneumoconioses

Pneumoconioses are still a common cause of chronic lung disease. In industrialized countries, improvements in working conditions and dust control measures have led to a decrease in the incidence of severe forms of silicosis, coal worker pneumoconiosis, and parenchymal asbestosis. However, the diversity of settings in which silica and asbestos are used fuels a continued input of cases, and the burden of cases related to remote exposures is still considerable. Overall, the clinical picture of the classic pneumoconioses and their complications has not changed substantially. However, their limits and links have expanded toward systemic and connective tissue disease, idiopathic pulmonary fibrosis, and antineutrophil cytoplasmic autoantibody-positive vasculitides. Immunologically mediated occupational lung diseases have emerged, such as berylliosis and hard-metal disease. Advances in imaging, mineralogic analysis of bronchoalveolar lavage fluid, and immunologic techniques have been instrumental in describing new patterns of disease and are helpful in litigious or difficult cases.

Mixed dust fibrosis and tuberculosis in comparison with silicosis and macular pneumoconiosis

BACKGROUND

To assess the relationship between mixed dust fibrosis (MDF) and tuberculosis.

METHODS

We performed a comparative analysis with MDF, silicosis, and macular pneumoconiosis (Mac), using autopsy records from 1975 to 1994.

RESULTS

Prevalences of having tuberculosis among MDF, silicosis, and Mac were not significantly different, albeit a tendency of higher prevalence in silicosis. Cure rates of tuberculosis were, in order, silicosis < MDF < Mac (P=0. 085). Death rates associated with tuberculosis were, in order, silicosis > MDF=Mac (P=0.911). With respect to the two types of association with tuberculosis, i.e., combined type (tuberculopneumoconiosis) and complicated one (pneumoconiosis with tuberculosis); the former was significantly dominant in silicosis, the latter was significantly dominant in Mac, and intermediate in MDF. As a whole, the complicated type had a tendency of a higher cure rate than the combined type (P=0.071). Although the differences of profiles between the combined and complicated types were not statistically significant, the combined type had a tendency to have longer duration of exposure to dusts, earlier registration for treatment, higher profusion score, and earlier death compared with the complicated type.

CONCLUSIONS

From our findings, MDF takes an intermediate position between silicosis and Mac regarding the relationship with tuberculosis. The type of association with tuberculosis rather than the kind of background pneumoconiosis seemed to be more important in light of responsiveness to the treatment.

Occurrence and prevention of coal miners' pneumoconiosis in Poland

BACKGROUND

Coal production is one of the largest industries in Poland and incidence of coal miners' pneumoconiosis is high.

METHODS

Data concerning the epidemiology of coal miners' pneumoconiosis stem from the national register and previous investigations performed in Poland. Improvements in medical and technical methodologies for the prevention of pneumoconiosis is discussed.

RESULTS

Analysis of the dust concentration measurements shows that TLV values are exceeded in 90% of underground workplaces. The number of new pneumoconiosis cases diagnosed annually ranges from 400-800 and has been showing a diminishing tendency in the last five years. Recently, a new system of medical and technical prevention has been introduced in seven collieries.

CONCLUSIONS

The current epidemiological situation of coal miners pneumoconiosis in Poland is unfavorable and needs vast improvement.

[Metabolism of serum phospholipids in coal miners]

The studies covered metabolism of serum phospholipids during lipids peroxidation and hydrolysis by phospholipase A2. Metabolism of serum phospholipids appeared to depend on duration of exposure to mine dust and on coal pneumoconiosis stage. Lipids peroxidation becomes activated after 20 and more years of service, intensifies with anthracosilicosis development on background of higher catalase activity that is low on early stages of the disease. Activity of phospholi pase A2 increases with pulmonary fibrosis progression.

Between a rock and a healthy place

The Federal Mine Safety and Health Act of 1977 consolidated all federal health and safety regulations of the mining industry-coal as well as noncoal mining-under a single mandate administered by the Mine Safety and Health Administration (MSHA). Today, the agency is striving to reduce the environmental health risks associated with mining.

Occupational lung diseases and global occupational health on the Net

Occupational lung disease is a major area of concern in occupational health, exhibiting a diverse panorama across countries. While pneumoconiosis is deemed to be the most common occupational disease in many developing countries, emphasis is shifting towards asbestos-related lung diseases and occupational asthma in industrialized countries. Following the Occupational Health for All strategies set forth by the World Health Organization, we propose that a model system based upon the Global Health Network can serve as an effective vehicle towards the prevention of occupational lung diseases on a global scale. It has the potential to: (1) enhance transmission of data and collaboration with the primary health care system in disease surveillance; (2) strengthen research and information transfer and (3) promote education and training at all levels of prevention, with a possible application to the interpretation of chest radiograms.

[Experimental study on prevention of pneumoconiosis complicating with tuberculosis by Mycobacterium vaccae]

OBJECTIVE

To explore the role of Mycobacterium vaccae in prevention of pneumoconiosis complicating with tuberculosis.

METHOD

Mycobacterium vaccae was injected into rats which had been exposed to quartz for 2 weeks, and H37Rv was injected into their tail veins 1 month later. All the rats were killed 3 months later. Indexes for evaluation in the study included tuberculous lesion pathological change index, Mycobacterium tuberculosis culture in a fixed amount in lung tissues, count of Mycobacterium tuberculosis and histopathological changes in alveolar macrophages.

RESULT

Tuberculous lesion pathological change index, Mycobacterium tuberculosis culture in a fixed amount in lung tissues and count of Mycobacterium tuberculosis in alveolar macrophages were 2.6 +/- 0.5, (4.40 +/- 4.00) x 10(4) CFU and 7.2 +/- 3.2 respectively in pneumoconiosis complicated with tuberculosis and injecting Mycobacterium vaccae group, while 3.1 +/- 0.3, (18.9 +/- 18.2) x 10(4) CFU and 12.5 +/- 6.3 respectively in the control group. And statistically significant differences were found between the two groups (P < 0.05, 0.01, 0.05 respectively). The histopathological analysis revealed that proliferative and lymphoid nodules were predominant in the pneumoconiosis complicated with tuberculosis and injecting Mycobacterium vaccae group, while necrotic nodules in the control group.

CONCLUSION

Mycobacterium vaccae might play a role in prevention of pneumoconiosis complicating with tuberculosis.