Background China is the world's largest producer and consumer of cobalt. Skin exposure to excess cobalt can cause symptoms such as contact dermatitis. At present, there are few studies on skin contact of cobalt and its compounds. Objective To investigate the skin contact characteristics of cobalt and its compounds. Methods A cross-sectional study was conducted in February 2024 involving 70 workers from a hard metal tool manufacturing company and the workers were divided into four groups according to their job positions: powder mixing, sintering, automatic pressing, and grinding processing. General demographic information was collected through questionnaires. Workplace air samples were collected using personal samplers, and cobalt concentrations in workplace air were measured by inductively coupled plasma optical emission spectrometry (ICP-OES). Skin samples were collected from the workers' foreheads using cotton swabs, and urine samples were collected within 30 min after the end of their shift. Urine specific gravity was measured immediately after collection, and disqualified samples were discarded. Cobalt concentrations in the swab extracts and urine were determined by inductively coupled plasma mass spectrometry (ICP-MS). Statistical analysis was performed using Kruskal-Wallis test for multiple group comparisons, Mann-WhitneyU test for pairwise comparisons, Chi-square test for categorical variables, and Spearman's rank correlation analysis to examine the correlations among air, dermal, and urinary cobalt levels. Results The 8 h time-weighted average (TWA) cobalt concentration was (2.30±2.15) μg·m⁻³ (\begin{document}$ \bar{x}\pm s $\end{document}). The median skin exposure level was 53.8 ng·cm⁻², with a range of 4.25 ng·cm⁻² to 1090.2 ng·cm⁻². The median urinary cobalt level was 3.74 µg·L⁻¹, with a range of 0.83 to 382.9 µg·L⁻¹. Statistically significant differences in TWA cobalt concentration, skin exposure levels, and urinary cobalt levels were found between different work positions (H=9.012, P=0.029; H=16.348, P＜0.001; H=11.078, P=0.011). A positive correlation was observed between skin exposure levels and urinary cobalt levels (r=0.537, P＜0.01). Conclusion Skin contact may be one of the main sources of cobalt levels in urine. Therefore, it is essential for workers to improve skin protection and hygiene practices.

Background Coal workers' pneumoconiosis is a serious occupational disease in China. Exhaled volatile organic compounds (VOCs) can serve as the "breath fingerprint" of internal pathological processes, which provides a theoretical basis for exhaled VOCs to be used as potential non-invasive biomarkers for early diagnosis of coal workers' pneumoconiosis. Objective To screen out the characteristic VOCs and important characteristic VOCs of exhaled air in patients with coal workers' pneumoconiosis, and to explore the potential of these VOCs as biomarkers for early non-invasive diagnosis of the disease. Methods In this study, 27 VOCs in the exhaled breath of 22 patients with stage I coal workers' pneumoconiosis, 77 workers exposed to dust, and 92 healthy controls were quantitatively detected by thermal desorption gas chromatography-mass spectrometry (TD-GC-MS). Substances with P<0.05 in univariate analysis and variable importance projection (VIP) >1 in supervised orthogonal partial least squares discriminant analysis (OPLS-DA) model were selected as the characteristic VOCs for early diagnosis of coal workers' pneumoconiosis. Age was included in the LASSO regression model as a covariate to screen out important characteristic VOCs, and the diagnostic performance was evaluated by receiver operating characteristic (ROC) curve. Spearman correlation was further used to explore the correlation between important characteristic VOCs and clinical lung function indicators. Results Through univariate analysis and OPLS-DA modeling, 8 VOCs were selected, including 2-methylpentane, 3-methylpentane, n-hexane, methylcyclopentane, n-heptane, methylcyclohexane, 4-methyl-2-pentanone, and 2-hexanone, in exhaled breath of patients with coal workers' pneumoconiosis. The concentrations of 4 VOCs, including 3-methylpentane, n-hexane, 4-methyl-2-pentanone, and 2-hexanone, showed a decreasing trend with the increase of dust exposure years. By LASSO regression, the important characteristic VOCs of the coal workers' pneumoconiosis group and the dust exposure group were n-hexane, methylcyclohexane and 4-methyl-2-pentanone, and the important characteristic VOCs of the coal workers' pneumoconiosis group and the healthy group were 2-methyl-pentane and 4-methyl-2-pentanone. The ROC analysis showed that the area under the curve (AUC) of n-hexane, methylcyclohexane, and 4-methyl-2-pentanone were 0.969, 0.909, and 0.956, respectively, and the AUC of combined diagnosis was 0.988 and its Youden index was 0.961, suggesting that these results can serve as a valuable reference for further research on early diagnosis. The Correlation analysis found that there was a positive correlation between n-hexane and lung function indicators in the important characteristic VOCs, indicating that it could indirectly reflect the obstruction of lung function ventilation, further proving that important characteristic VOCs have the potential to monitor lung function decline. Conclusion Three important characteristic VOCs selected in this study have the potential to be used as non-invasive biomarkers for early diagnosis and disease monitoring of coal workers' pneumoconiosis, and are worthy of further study and verification.

The composition and concentration of volatile organic compounds (VOCs) in exhaled breath are closely related to human health and the analysis of VOCs by collecting human exhaled breath has been widely used in disease surveillance research. This article reviewed the collection, enrichment, and detection methods of exhaled VOCs, which can provide a reference for selecting appropriate technology for follow-up research. The exhaled breath collection devices mainly include sampling bags for mixed exhaled breath and biological volatile organic compound (Bio-VOC) samplers for alveolar air. The pre-enrichment equipment included thermal desorption (TD), solid-phase microextraction device (SPME), and needle trap device (NTD). The detection methods of exhaled VOCs include gas chromatography-mass spectrometry (GC-MS), proton transfer reaction mass spectrometry (PTR-MS), selective ion flow tube mass spectrometry (SIFT-MS), and electronic nose. At present, the collection and enrichment technology of exhaled breath is not mature yet, and its influence on the results of detection is lack of evaluation. In the future, the research on collection and enrichment technology of exhaled breath should be strengthened to further promote the application of exhaled breath in disease surveillance research.

Occupational pneumoconiosis (referred to as “pneumoconiosis”) caused by exposure to occupational dust is the most serious occupational disease in China. Biological monitoring on occupational populations exposed to dust is important for the prevention, diagnosis, and treatment of pneumoconiosis. Biological monitoring is a systematic engineering process that includes a series of processes such as biological samples selection, selection of biological monitoring indicators, and selection of detection methods. The biological samples for biological monitoring mainly include urine, blood, exhaled breath gas, bronchoalveolar lavage fluid, saliva, sputum, and more. The indicators of biological monitoring involve multiple pathways such as oxidative stress, inflammatory response, collagen synthesis/degradation, phagocytic cell apoptosis, and pathways related to the formation of pneumoconiosis. Suitable detection methods need to be determined upon different biological monitoring indicators, including enzyme-linked immunosorbent assay, high-performance liquid chromatography, high-performance liquid chromatography-tandem mass spectrometry, inductively coupled plasma mass spectrometry, etc. Currently, there is a lack of true clinically valuable biological monitoring indicators that can indicate the correlation between dust exposure and the hazards of occupational populations, and there are no systematic and complete biological monitoring methods reported. It is necessary to further standardize the biological monitoring process and search for specific biological monitoring indicators.

Objective:To establish a method for determination of Perchloroethylene (PCE) in blood by headspace gas chromatography-mass spectrometry (HS/GC-MS) .Methods:From Dctober to December 2021, A total of 3 mL blood samples were taken into a 10 mL headspace bottle, after heated at 60 ℃ for 30 mins, PCE in the top air was separated by VF-WAXms capillary column and detected by GC-MS. The retention time and external standard method were used for qualitative and quantitative analysis of PCE in samples, respectively.Results:There was good linear relationship in the range of 5.09-200.17 μg/L. The linear correlation coefficient was 0.9993.The detection limit was 0.21 μg/L and the lower limit of quantitation was 0.70 μg/L. The recovery rates of samples with different concentrations were 95.3%-103.8%. The intra-batch relative standard deviations ( RSD) were 3.2%-4.6%, and inter-batch RSD was 4.0%-6.1%. The samples can be stored at 4 ℃ for three days and at -20 ℃ for seven days. Conclusion:This method is proved to be simple, practical and highly sensitive, which is suitable for the determination of PCE in blood.

Silicosis is a common occupational disease, and its main characteristic pathological features are the formation of silicon nodules and diffuse pulmonary fibrosis. In the process of silicosis fibrosis, macrophages can be polarized into M1 macrophages and M2 macrophages. M1 macrophages play a pro-inflammatory role in the early stage of silicosis and release a variety of inflammatory factors, which is the core of inflammatory response. M2 macrophages promote inflammation resolution and tissue repair in silicosis fibrosis stage by secreting anti-inflammatory cytokines and pro-fibrotic mediators. M1/M2 polarization balance plays an important role in the occurrence and development of silicosis, and the regulation of macrophage polarization direction may play a positive role in the prevention and treatment of silicosis fibrosis. In this review, the role of macrophage polarization in silicosis fibrosis, the related signaling pathways regulating macrophage polarization in silicosis fibrosis, and the potential therapeutic targets based on macrophage polarization in silicosis fibrosis are reviewed, with a view to further strengthening the understanding of the mechanism of macrophage polarization in the pathogenesis and treatment of silicosis fibrosis.

Objective:To establish a method for determination of Perchloroethylene (PCE) in blood by headspace gas chromatography-mass spectrometry (HS/GC-MS) .Methods:From Dctober to December 2021, A total of 3 mL blood samples were taken into a 10 mL headspace bottle, after heated at 60 ℃ for 30 mins, PCE in the top air was separated by VF-WAXms capillary column and detected by GC-MS. The retention time and external standard method were used for qualitative and quantitative analysis of PCE in samples, respectively.Results:There was good linear relationship in the range of 5.09-200.17 μg/L. The linear correlation coefficient was 0.9993.The detection limit was 0.21 μg/L and the lower limit of quantitation was 0.70 μg/L. The recovery rates of samples with different concentrations were 95.3%-103.8%. The intra-batch relative standard deviations ( RSD) were 3.2%-4.6%, and inter-batch RSD was 4.0%-6.1%. The samples can be stored at 4 ℃ for three days and at -20 ℃ for seven days. Conclusion:This method is proved to be simple, practical and highly sensitive, which is suitable for the determination of PCE in blood.

Silicosis is a common occupational disease, and its main characteristic pathological features are the formation of silicon nodules and diffuse pulmonary fibrosis. In the process of silicosis fibrosis, macrophages can be polarized into M1 macrophages and M2 macrophages. M1 macrophages play a pro-inflammatory role in the early stage of silicosis and release a variety of inflammatory factors, which is the core of inflammatory response. M2 macrophages promote inflammation resolution and tissue repair in silicosis fibrosis stage by secreting anti-inflammatory cytokines and pro-fibrotic mediators. M1/M2 polarization balance plays an important role in the occurrence and development of silicosis, and the regulation of macrophage polarization direction may play a positive role in the prevention and treatment of silicosis fibrosis. In this review, the role of macrophage polarization in silicosis fibrosis, the related signaling pathways regulating macrophage polarization in silicosis fibrosis, and the potential therapeutic targets based on macrophage polarization in silicosis fibrosis are reviewed, with a view to further strengthening the understanding of the mechanism of macrophage polarization in the pathogenesis and treatment of silicosis fibrosis.

Background Volatile organic compounds (VOCs) in exhaled breath are closely associated with respiratory diseases and are linked to various metabolic reactions in the human body. A quantitative analytical method can provide technical support for studying VOCs related to various diseases. Objective To establish a thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) method for the determination of 27 VOCs in exhaled breath. Methods VOCs in exhaled breath were collected using a Bio-VOC sampler and enriched with Tenax TA thermal desorption tubes before TD-GC-MS analysis. Standards were collected using thermal desorption tubes and optimized for thermal desorption conditions as well as chromatographic and mass spectrometric conditions: The separation of the 27 VOCs was achieved by an optimized temperature program, the improvement of sensitivity by optimizing quantitative ions, and the increase of VOCs desorption efficiency by optimizing thermal desorption time and temperature. Limit of detection, limit of quantification, accuracy, precision, and stability of the proposed method were investigated by spiking with a blank gas bag, and exhaled breath samples from 20 healthy individuals were collected for an application study of the proposed method. Results The thermal desorption temperature was 280 ℃, and desorption time was 6 min. A VF-624ms chromatographic column was selected for the separation of target substances. The initial temperature of heating program was 35 ℃, maintained for 1 min, and then increased to 100 ℃ at a heating rate of 3 ℃·min⁻¹ for 1 min, followed by increasing to 210 ℃ at a heating rate of 28 ℃·min⁻¹ for 5 min. A quantitative analysis was conducted with a single ion monitoring (SIM) mode. Under these conditions, the 27 VOCs showed good linear relationships in their respective concentration ranges and the correlation coefficients were higher than 0.9990. The limits of detection of the method were in the range of 0.01-0.13 nmol·mol⁻¹, the limits of quantification were in the range of 0.02-0.44 nmol·mol⁻¹, and the spiked recoveries were in the range of 80.1%-120.5%, with intra-batch and inter-batch precision ≤ 18.8% and 17.9% respectively. All substances can be stored at room temperature (23-28 °C) for 7 d and at 4 °C for 14 d. The proposed method was applied to exhaled breath samples from 20 subjects with detection rates≥ 80% (except for trans-2-pentene and decane) and a concentration range of 0.00-465.50 nmol·mol⁻¹. Conclusion The established TD-GC-MS method for quantification of VOCs in exhaled breath is characterized by high sensitivity and good accuracy, and is suitable for quantitative determination of VOCs in exhaled breath, which can provide technical support for the study of exhaled breath VOCs.

Objective:To evaluate the accuracy and applicability of detection tube method for quantitative detection of hydrogen sulfide in workplace air.Methods:In September 2021, the lower limit of quantification, accuracy, precision, environmental factors, interfering gases and other performance indicators of the method for determining hydrogen sulfide in the air of workplace were verified by the detection tube, and the results were compared with those of GB 11742-89 "Standard method for hygienic examination of hydrogen sulfide in air of residential areas-methylene blue spectrophotometric method" to evaluate the application effect of the detection tube method for quantitative detection of hydrogen sulfide in workplace air.Results:There was no significant difference in the results of 2.83 mg/m 3, 4.25 mg/m 3 and 17.00 mg/m 3 hydrogen sulfide concentration between the two methods ( P>0.05) , but there was significant difference in the results of 8.50 mg/m 3 concentration ( P<0.05) . The lower limit of quantification of hydrogen sulfide in workplace air was 2.83 mg/m 3, the accuracy was 96.0%-111.0%, and the precision was 0.70%-6.64%. Under the condition of 4 ℃, the measured results decreased by 3.39%-13.10%. When the humidity was 50%-80%, the relative error of the average measured value was -1.67%-4.44%. Interference gases that may exist in the workplace (including carbon dioxide, carbon monoxide, mercaptans, nitrogen oxides, sulfur dioxide, etc.) did not interfere with the results of the test tube. Conclusion:The accuracy and precision of the detection tube method meet the detection requirements. The method is simple, rapid and easy to be popularized, and can be used for the rapid detection of hydrogen sulfide gas concentration in the workplace.