Heavy metal worker's pneumonoconiosis with lung parenchymal damage and Peripheral neuropathy: case report.

Heavy metals even at low concentrations can damage all systems in the human body from the cellular level by causing disruptions in DNA repair mechanisms, cell division and apoptosis. A 49-year-old man who had been working in the sanding and deburring department of a factory producing underground water pipes for 15 years, presented with complaints of effort dyspnea, cough and loss of strength in his left hand. Computed tomography of the lung revealed diffuse micronodular appearance in all zones in both lungs, subpleural nodule and bronchial dilatation. All serological tests for autoimmune disease were negative. Neurological examination of the patient revealed signs of 2nd motor neuron involvement only in one upper extremity. All of the tests that were studied for the differential diagnosis of multifocal motor neuropathy were found negative. Open lung biopsy with videothoracoscopy was practiced and interstitial changes were observed in the lung parenchyma with intense iron accumulation with Prussian blue stain. The patient was diagnosed with hard metal lung disease (HMLD) and toxic neuropathy (TN) with peripheral nerve involvement due to exposure to metal dust in the working environment. Although the patient had no loss of lung function, he was removed from the working environment, because of function loss in the left hand and is still being followed up.

Interstitial lung disease related to occupational hard metal exposure: two case reports.

BACKGROUND: Hard metal lung disease (HMLD) is a relatively less known occupational interstitial lung disease, and instances of HMLD resulting from para-occupational exposure are rarely reported. CASE PRESENTATION: This paper presents two cases of interstitial lung disease caused by exposure to hard metal. The first case involves a 37-year-old Taiwanese man who had worked at a grinder station for hard metal materials for 12 years without respiratory protective equipment. He experienced a dry cough and exertional dyspnea, and his chest imaging and pathology findings were consistent with the features of usual interstitial pneumonia. Analysis of his lung tissue revealed the presence of tungsten and cobalt. The second case involves a 68-year-old Taiwanese woman, the mother of the first patient, who had hand-washed her son's workwear. She experienced a dry cough and had similar imaging findings to her son. After her son left his job, they both exhibited improved symptoms and lung functions with nintedanib treatment. These findings suggest a diagnosis of HMLD and interstitial lung disease resulting from para-occupational exposure to hard metal dust. CONCLUSIONS: The diagnosis of HMLD relies on obtaining a detailed occupational exposure history. If HMLD is diagnosed, discontinuing exposing to hard metal dusts can lead to improved lung function.

Analysis of lung function and respiratory symptoms in brass/metal industrial workers of Moradabad, Uttar Pradesh, India.

Background: The job demands of some of the industries have been reported to be hazardous to the health and safety of workers. Workplace environmental hazards or occupational hazards are a globally major cause of disability and mortality among the working population. The present study was done to analyze the effect of exposure to metal dust on pulmonary function and respiratory symptoms. Materials and Methods: The study population selected as cases were 200 male mill workers working for at least 1-year duration (direct exposure) in the age group of 20-50 years, and controls were 200 age- and gender-matched male participants without any history of occupational or environmental exposure. A complete history was taken. Spirometry was done. Spirometric parameters studied were forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), ratio of FEV1 and FVC, and peak expiratory flow rate (PEFR). The spirometry data and baseline characteristics of the participants were compared using unpaired t-test. Results: The mean age of the participants of the study group and the control group was 42.3 years and 44.1 years, respectively. The majority of the study population belonged to the age group of 41-50 years. The mean FEV1 value among participants of the study group and control group was 2.69 and 2.13, respectively. The mean FVC value among participants of the study group and control group was 3.18 and 3.63, respectively. The mean FEV1/FVC value among participants of the study group and control group was 84.59% and 86.22%, respectively. The mean PEFR value among the study group and control group was 7.78 and 8.67, respectively. While analyzing statistically, mean lung functional tests were significantly lowered among the study group. About 69.5% of the participants of the study group thought it to be essential for making safety measures a necessity. Conclusion: The present study concluded that mean lung functional tests were significantly lowered among the study group. Despite the use of face mask, lung function abnormality was present in mill workers.

Résumé Contexte: Les exigences professionnelles de certaines industries ont été signalées comme étant dangereuses pour la santé et la sécurité des travailleurs. Les risques environnementaux sur le lieu de travail ou les risques professionnels sont une cause majeure d'invalidité et de mortalité au sein de la population active. La présente étude a été réalisée pour analyser l'effet de l'exposition à la poussière métallique sur la fonction pulmonaire et les symptômes respiratoires. Matériels et méthodes: La population étudiée sélectionnée comme cas était composée de 200 hommes travaillant dans des usines pendant au moins un an (exposition directe) dans le groupe d'âge 20-50 ans. Les témoins étaient 200 participants masculins appariés par l'âge et le sexe, sans aucun antécédent d'exposition professionnelle ou environnementale. Une anamnèse complète a été réalisée. Une spirométrie a été effectuée. Les paramètres spirométriques étudiés étaient la capacité vitale forcée (CVF), le volume expiratoire forcé en 1 s (VEMS), le rapport entre le VEMS et la CVF, et le débit expiratoire de pointe (DEP). Les données spirométriques et les caractéristiques de base des participants ont été comparées à l'aide d'un test t non apparié. Résultats: L'âge moyen des participants du groupe d'étude et du groupe et du groupe témoin était de 42,3 ans et 44,1 ans, respectivement. La majorité de la population étudiée appartenait à la tranche d'âge des 41-50 ans. La valeur moyenne du VEMS parmi les participants du groupe d'étude et du groupe témoin était de 2,69 et 2,13, respectivement. La valeur moyenne de la CVF parmi les participants du groupe d'étude et du groupe témoin était de 3,18 et 3,63, respectivement. La valeur moyenne VEMS/CVF chez les participants du groupe d'étude et du groupe témoin était de 84,59 % et 86,22 %, respectivement. La valeur moyenne de la PEFR parmi les participants du groupe groupe étudié et le groupe témoin était de 7,78 et 8,67, respectivement. Lors de l'analyse statistique, les tests fonctionnels pulmonaires moyens ont été significativement réduits dans le groupe étudié. dans le groupe d'étude. Environ 69,5 % des participants du groupe d'étude ont estimé qu'il était essentiel de prendre des mesures de sécurité. Conclusion: La présente étude a conclu que les tests fonctionnels pulmonaires moyens étaient significativement abaissés dans le groupe étudié. Malgré l'utilisation masque facial, les travailleurs de l'usine présentaient des anomalies de la fonction pulmonaire. Mots-clés: Poussière de métal dur, test de fonction pulmonaire, symptômes respiratoires.

Giant Cell Interstitial Pneumonia In Native, Transplanted And Re-Transplanted Lungs 8 Years Apart Without Known Hard Metal Exposure.

Pneumoconioses are a group of non-neoplastic pulmonary disorders caused by inhaled inorganic particles. Well-described pneumoconioses include asbestosis, silicosis, coal worker's pneumoconiosis, chronic beryllium disease, and hard metal lung disease. Giant cell interstitial pneumonia (GIP) is a distinctive and rare pneumoconiosis most frequently found in workers exposed to hard metals, primarily cobalt and tungsten carbide. The pathologic picture is considered virtually pathognomonic for hard metal lung disease, although this dogma has been questioned by a few reports of giant cell interstitial pneumonia in patients without apparent hard metal exposure. Giant cell interstitial pneumonia is even rarer in lung transplant recipients. Here, we present a patient without known hard metal exposure who was found to have persistent giant cell interstitial pneumonia in native, transplanted and re-transplanted lungs 8 years apart.

Spark Plasma Sintering of WC-Based 10wt%Co Hard Alloy: A Study of Sintering Kinetics and Solid-Phase Processes.

The paper describes the method for producing WC-10wt%Co hard alloy with 99.6% of the theoretical density and a Vickers hardness of ~1400 HV 0.5. Experimental data on densification dynamics, phase composition, morphology, mechanical properties, and grain size distribution of WC-10%wtCo using spark plasma sintering (SPS) within the range of 1000-1200 °C are presented. The high quality of the product is provided by the advanced method of high-speed powder mixture SPS-consolidation at achieving a high degree of densification with minimal calculated grain growth at 1200 °C.

The effect of different drugs on hard metal lung disease in a rat model.

Hard metal lung disease (HMLD) drugs include dexamethasone sodium phosphate (Dex), methylprednisolone (MP) injection, N-acetylcysteine injection (NAC), and a mix of Dex, MP, and NAC (MIX). In this study, we compared the effects of these drugs on different cytokines of hard metal lung disease in a rat model. Thirty-six adult female Sprague Dawley rats were distributed equally into the control group, hard metal (HM) group, Dex group, MP group, NAC group, and MIX group. HM powder (0.5 mL, 20 mg/mL; one time) was administered by intraperitoneal injection to the HM group through the pulmonary endotracheal tube, while the control group received normal saline (0.5 mL, 20 mg/mL; one time). After 4 weeks, the drugs were administered to the experimental groups (0.5 mL, 20 mg/mL; one time). After 8 weeks, bronchoalveolar lavage fluid (BALF) and serum were examined for cytokine levels. Biochemical analysis indicated that the Dex, MP, NAC, and MIX did not improve TGF-ß1, TGF-ß2, KL-6, and MMP-1 in the BALF, while MIX increased TIMP-1 in BALF. In addition, the NAC treatment significantly increased the expression levels of TGF-ß1, TGF-ß2, KL-6, and MMP-1. The MIX treatment significantly increased the expression levels of TGF-ß1, TGF-ß2, and KL-6. The MP treatment significantly increased the expression levels of KL-6, and MMP-1. The Dex treatment significantly increased the expression levels of TGF-ß1, KL-6, and MMP-1. This study demonstrated that administered with NAC and MIX could improve TGF-ß1, TGF-ß2, and KL-6 in serum of hard metal lung disease in a rat model. Therefore, NAC injection may be considered a useful candidate in the development of a preventive agent against HMLD.

PTX3 alleviates hard metal-induced acute lung injury through potentiating efferocytosis.

Prolonged exposure to hard metal dust results in hard metal lung disease (HMLD) characterized by respiratory symptoms. Understanding the pathogenesis and pathological process of HMLD would be helpful for its early diagnosis and treatment. In this study, we established a mouse model of hard metal-induced acute lung injury through one-time intratracheal instillation of WC-Co dust suspension. We found that WC-Co treatment damaged the lungs of mice, leading to increased production of IL-1ß, TNF-α, IL-6 and IL-18, inflammatory cells infiltration and apoptosis. In vitro, WC-Co induced cytotoxicity, inflammatory response and apoptosis in macrophages (PMA-treated THP-1) and epithelial cells (A549) in a dose-dependent manner. Moreover, RNA-sequence and validation experiments verified that Pentraxin 3 (PTX3), an important mediator in the regulation of inflammation, was elevated both in vivo and in vitro induced by WC-Co. Functional experiments confirmed the PTX3, which was located on the membrane of apoptotic cells, promoted macrophage efferocytosis efficiently. This progress could help block the lung inflammation and contribute to the rapid recovery of WC-Co-induced acute lung injury. These observations provide a further understanding of the molecular mechanism of WC-Co-induced pulmonary injury and disclose PTX3 as a new potential therapeutic approach to relieve WC-Co-induced acute lung injury via efferocytosis.

The relationship between respiratory health and hard metal dust exposure: A cross-sectional study.

The frequency and severity of respiratory disorders among workers exposed to hard metal dust is not well known.The objective of this cross-sectional study is to report the prevalence of respiratory symptoms, functional status, and radiological findings in hard metal-exposed workers in Türkiye.Among 139 workers, 96 were machining workers, and 43 were industrial tool sharpening workers. Radiographic abnormalities compatible with pneumoconiosis were found 39% of the workers and were more in machining workers statistically significant.Also, in machining workers group, percentage of expected values of FVC was lower than industrial tool sharpening workers group. The prevalence of respiratory symptoms was 14.3%, and there was not a statistically significant difference in working groups. The study reveals that pulmonary symptoms, functional abnormalities, and radiological findings are mild. Assuming that reversibility may develop with avoidance from exposure when detected at this stage, early diagnosis of lung damage is essential.

Cobalt-related interstitial lung disease or hard metal lung disease: A case series of Chinese workers.

Hard metal lung disease (HMLD) is rarely diagnosed and is caused by the occupational inhalation of hard metal dust, mainly cobalt. The diagnosis of HMLD is based on a thorough occupational dust exposure combined with clinical-radiological-histological findings. We present a series of four Chinese workers who had occupational exposure to cobalt acid lithium or cobalt and tungsten dust. Four patients all complained of intermittent cough, chest tightness, or shortness of breath on exertion. High-resolution computed tomography scans presented bilateral ground-glass attenuation, consolidations, and/or reticular opacities with diffuse small nodules. Histologic findings showed that interstitial inflammation and fibrotic lesions distributed peribronchioles. The infiltrations by macrophages as well as visible multinucleated giant cells indicated giant cell interstitial pneumonia (GIP). Cobalt was detectable in the lung tissues of two patients measured by inductively-coupled plasma mass spectrometry. The first patient was diagnosed with cobalt-related interstitial lung disease (ILD), while the others were HMLD. GIP is the classic pathology of cobalt-related ILD or HMLD. One of the patients showed spontaneous remission after the cessation of exposure, while the other three recovered within 6-32 weeks after avoiding occupational exposure and using corticosteroids. At follow-up, all four patients showed no recurrence. A multidisciplinary diagnostic panel including occupational cobalt exposure evaluation is beneficial to recognize cobalt-related ILD or HMLD and to indicate the necessity of prevention.

Inflammatory and coagulatory markers and exposure to different size fractions of particle mass, number and surface area air concentrations in the Swedish hard metal industry, in particular to cobalt.

PURPOSE: To study the relationship between inhalation of airborne particles and cobalt in the Swedish hard metal industry and markers of inflammation and coagulation in blood. METHODS: Personal sampling of inhalable cobalt and dust were performed for subjects in two Swedish hard metal plants. Stationary measurements were used to study concentrations of inhalable, respirable, and total dust and cobalt, PM10 and PM2.5, the particle surface area and the particle number concentrations. The inflammatory markers CC16, TNF, IL-6, IL-8, IL-10, SAA and CRP, and the coagulatory markers FVIII, vWF, fibrinogen, PAI-1 and D-dimer were measured. A complete sampling was performed on the second or third day of a working week following a work-free weekend, and additional sampling was taken on the fourth or fifth day. The mixed model analysis was used, including covariates. RESULTS: The average air concentrations of inhalable dust and cobalt were 0.11 mg/m3 and 0.003 mg/m3, respectively. For some mass-based exposure measures of cobalt and total dust, statistically significant increased levels of FVIII, vWF and CC16 were found. CONCLUSIONS: The observed relationships between particle exposure and coagulatory biomarkers may indicate an increased risk of cardiovascular disease.

Cobalt nanoparticles trigger ferroptosis-like cell death (oxytosis) in neuronal cells: Potential implications for neurodegenerative disease.

The neurotoxicity of hard metal-based nanoparticles (NPs) remains poorly understood. Here, we deployed the human neuroblastoma cell line SH-SY5Y differentiated or not into dopaminergic- and cholinergic-like neurons to study the impact of tungsten carbide (WC) NPs, WC NPs sintered with cobalt (Co), or Co NPs versus soluble CoCl2 . Co NPs and Co salt triggered a dose-dependent cytotoxicity with an increase in cytosolic calcium, lipid peroxidation, and depletion of glutathione (GSH). Co NPs and Co salt also suppressed glutathione peroxidase 4 (GPX4) mRNA and protein expression. Co-exposed cells were rescued by N-acetylcysteine (NAC), a precursor of GSH, and partially by liproxstatin-1, an inhibitor of lipid peroxidation. Furthermore, in silico analyses predicted a significant correlation, based on similarities in gene expression profiles, between Co-containing NPs and Parkinson's disease, and changes in the expression of selected genes were validated by RT-PCR. Finally, experiments using primary human dopaminergic neurons demonstrated cytotoxicity and GSH depletion in response to Co NPs and CoCl2 with loss of axonal integrity. Overall, these data point to a marked neurotoxic potential of Co-based but not WC NPs and show that neuronal cell death may occur through a ferroptosis-like mechanism.

Occupational low-level exposure to hard metals: cobalt and tungsten biomonitoring as an effective tool to evaluate the effectiveness of industrial hygiene interventions for risk management.

Purpose: The aim of the study was to assess the exposure to Cobalt (Co) and Tungsten (W) in a group of hard metal tool sharpeners through a combined approach of air and biological monitoring, and to evaluate the effectiveness of a control and improvement intervention carried out in collaboration with the medical officers of the local Health Protection Agency, by biomonitoring.Methods: We enrolled 132 workers from 17 companies of the province of Brescia, northern Italy. The study was performed in two phases: (1) an environmental and biomonitoring survey to assess the workers' exposure to Co and W at their usual working conditions; (2) a further biomonitoring survey 3 months after the enforcement of a control and improvement intervention, to assess its effectiveness.Results: Workers were found to be exposed to low concentration of airborne dust containing Co and W but after the intervention we recorded a significant decrease of the urinary concentrations of both Co and W. The extent of the decrease was correlated to the number of preventive industrial hygiene interventions that were carried out.Conclusions: Biological monitoring of Co and W in the hard metal tools manufacturing industry is a sensitive and effective method to evaluate the effectiveness of prevention practices.

Comparison of Retention and Seating of Implant-Supported Hard and Soft Metal Copings.

Objectives: Implant-supported restorations are generally used for the replacement of the lost teeth. Stability against masticatory forces and proper retention are critical for optimal durability of restorations. The aim of this experimental study was to compare the retention of cobalt-chromium (Co-Cr) copings made by different techniques. Materials and Methods: Twenty-four solid abutment analogs were mounted and scanned with a desktop scanner. They were divided into two groups (n=12) and received metal copings fabricated by either soft or hard Co-Cr alloy. Soft Ceramill Sintron Co-Cr patterns were milled and sintered. Hard Co-Cr blocks were milled in a milling machine. The copings were sandblasted, polished, adjusted, and placed on the respective abutments. The frequency of adjustments was recorded for each abutment. The copings were cemented with zinc phosphate cement and underwent tensile test by a universal testing machine. The Mann-Whitney test and t-test were used to compare the two groups (α=0.05). Results: There was no significant difference in retention of copings between the experimental groups. The mean retentive force was 559.58±115.66 N and 557.13 ±130.48 N for the soft and hard metal groups, respectively (P=0.96). Considering the non-normal distribution of adjustment frequency data, the Mann-Whitney test showed that the frequency of adjustments was significantly higher in the hard metal group than the soft metal group (9.5 versus 0.1667; P<0.001). Conclusion: Although hard metal copings required more adjustments, retention of soft and hard Co-Cr copings was not significantly different.

[Investigation of contact dermatitis caused by hard metal dust].

Objective: To investigate the incidence of contact dermatitis among workers in cemented carbide production enterprises. Methods: From October 1997 to October 2017, an occupational epidemiological survey was conducted on a large-scale cemented carbide production enterprise, and occupational health examinations were conducted for employees. 152 people were exposed to hard metal dust (hard metal raw material dust and alloy dust) . The employees in the work group were contact groups, and 142 employees in the non-dusting operation of the company were in the control group. A detailed retrospective survey of hard metal production workers with contact dermatitis history in the two groups was conducted to analyze the risk factors of contact dermatitis exposure to hard metal dust. Results: The incidence of allergic diseases in the exposed group was significantly higher than that in the control group. The difference was statistically significant (χ(2)=23.793, P<0.05) . The incidence of contact dermatitis in the exposed group was significantly higher than that in the control group. The difference was statistically significant (χ(2)=24.659, P<0.05) ; the changes of contact dermatitis in the contact group were mainly allergic contact dermatitis, and some showed irritative contact dermatitis; the operator had respiratory symptoms (including work-related nasal congestion, cough, wheezing) , difficulty breathing may be the influencing factors of contact dermatitis (RR=2.60, 95%CI: 1.10-6.20, P<0.05) . Conclusion: Hard metal alloy enterprises are exposed to hard metal dust. The incidence of contact dermatitis is high in workers, and the occurrence of contact dermatitis may be associated with those with respiratory symptoms.

Hard Metal Lung Disease with Favorable Response to Corticosteroid Treatment: A Case Report and Literature Review.

Hard metal lung disease (HMLD) is a pneumoconiosis caused by occupational exposure to hard metals such as tungsten carbide and cobalt, but the treatment strategies for HMLD have not been well established. A 68-year-old Japanese man with occupational history as a grinder of hard metals for 18 years referred to our hospital because of dry cough and dyspnea. A chest computed tomography (CT) on admission revealed centrilobular micronodules, ground-glass opacities, and reticular opacities in the peripheral zone of both lungs. Mineralogic analyses of lung tissues detected components of hard metals, such as tungsten, titanium and iron, and the same metals were also detected in the sample of the dust of his workplace. Thus, the patient was diagnosed as having HMLD based on occupational exposure history and radiologic and mineralogic analyses of the lung. Corticosteroid therapy was initiated, which resulted in partial improvements in his symptoms, radiological and pulmonary functional findings. In a review of the 18 case reports of HMLD treated with corticosteroids, including our case, the majority of patients (77.8%) showed favorable responses to corticosteroid treatment. Furthermore, the presence of fibrotic changes, such as reticular opacity, in radiological examinations was associated with the resistance to corticosteroids. In conclusion, the majority of patients with HMLD are expected to favorable response to corticosteroid treatment, whereas chest CT findings such as fibrotic changes may be predictive of the resistance of corticosteroid treatment. Lastly, proper prevention of hard metal exposure is most important as the first step.

Investigation of contact dermatitis caused by hard metal dust / 中华劳动卫生职业病杂志

Objective@#To investigate the incidence of contact dermatitis among workers in cemented carbide production enterprises.@*Methods@#From October 1997 to October 2017, an occupational epidemiological survey was conducted on a large-scale cemented carbide production enterprise, and occupational health examinations were conducted for employees. 152 people were exposed to hard metal dust (hard metal raw material dust and alloy dust) . The employees in the work group were contact groups, and 142 employees in the non-dusting operation of the company were in the control group. A detailed retrospective survey of hard metal production workers with contact dermatitis history in the two groups was conducted to analyze the risk factors of contact dermatitis exposure to hard metal dust.@*Results@#The incidence of allergic diseases in the exposed group was significantly higher than that in the control group. The difference was statistically significant (χ2=23.793, P<0.05) . The incidence of contact dermatitis in the exposed group was significantly higher than that in the control group. The difference was statistically significant (χ2=24.659, P<0.05) ; the changes of contact dermatitis in the contact group were mainly allergic contact dermatitis, and some showed irritative contact dermatitis; the operator had respiratory symptoms (including work-related nasal congestion, cough, wheezing) , difficulty breathing may be the influencing factors of contact dermatitis (RR=2.60, 95%CI: 1.10-6.20, P<0.05) .@*Conclusion@#Hard metal alloy enterprises are exposed to hard metal dust. The incidence of contact dermatitis is high in workers, and the occurrence of contact dermatitis may be associated with those with respiratory symptoms.

A case series describing common radiographic and pathologic patterns of hard metal pneumoconiosis.

INTRODUCTION: Hard metal pneumoconiosis is a rare but serious disease of the lungs associated with inhalational exposure to tungsten or cobalt dust. Little is known about the radiologic and pathologic characteristics of this disease and the efficacy of treating with immunosuppression. OBJECTIVE: We describe the largest cohort of patients with hard metal pneumoconiosis in the literature, including radiographic and pathologic patterns as well as treatment options. METHODS: We retrospectively identified patients from the University of Pittsburgh pathology registry between the years of 1985 and 2016. Experts in chest radiology and pulmonary pathology reviewed the cases for radiologic and pathologic patterns. RESULTS: We identified 23 patients with a pathologic pattern of hard metal pneumoconiosis. The most common radiographic findings were ground glass opacities (93%) and small nodules (64%). Of 20 surgical biopsies, 17 (85%) showed features of giant cell interstitial pneumonia. Most patients received systemic corticosteroids and/or steroid-sparing immunosuppression. CONCLUSIONS: Hard metal pneumoconiosis is characterized predominately by radiographic ground glass opacities and giant cell interstitial pneumonia on histopathology. Systemic corticosteroids and steroid-sparing immunosuppression are common treatment options.

Contamination of skin and surfaces by cobalt in the hard metal industry.

BACKGROUND: It is well known that hard metal workers have historically been affected by contact allergy to cobalt. Knowledge is sparse about occupational skin exposure to cobalt, in terms of skin doses and sources of exposure, which could be used to improve protection of workers. OBJECTIVES: To improve knowledge about skin doses and sources of skin exposure to cobalt within hard metal production, thereby facilitating better protection of workers. METHODS: Forty workers were sampled on the index finger by acid wipe sampling after 2 hours of work. The samples were analysed with inductively coupled plasma mass spectrometry. Cobalt spot testing was performed in the work environment. RESULTS: The highest skin doses were found among raw material workers. Skin doses among other production workers were also significant. Most office workers had low, but measurable, levels of cobalt on the skin. Glove use varied between workers. Cobalt was found on production equipment, on items in the canteen area, and on handles and buttons throughout the company. CONCLUSIONS: Cobalt skin doses were prominent, and originated from contact with raw materials, sintered materials, and contaminated surfaces. Cobalt was present on surfaces outside production areas. Companies need to identify and reduce skin exposure for protection of workers.

Study of lung toxicity in rats exposed to silica powder with different hard metal constituents.

The objective of this study was to assess the lung toxicity induced by the inhalation of different hard metal constituents and silica powder and screen for potential toxicity biomarkers. Rats were randomly divided into saline, cobalt, tungsten carbide, silica, and hard metal (HM) groups and were administered a single 10-mg dose of the respective treatments. After 8 weeks, the lung tissue structure in the HM group was deformed, numerous nucleated giant and epithelial-like cells appeared in the stroma, and the computed tomography scanning images appeared abnormal. Krebs von den Lungen-6 (KL-6), transforming growth factor (TGF)-ß1, and TGF-ß2 expression in bronchoalveolar lavage fluid (BALF) significantly differed between the groups ( p < 0.05). Serum KL-6 and TGF-ß1, but not TGF-ß2, levels significantly differed between some groups ( p < 0.05). We observed multinucleated giant cells in the rat lung tissue. While the serum and BALF levels of KL-6 and TGF-ß2 are not highly specific, TGF-ß1 may be a valuable reference diagnostic marker in HM lung disease.