BACKGROUND: It is inaccurate to reflect the level of dust exposure through working years. Furthermore, identifying a predictive indicator for lung function decline is significant for coal miners. The study aimed to explored whether club cell secretory protein (CC16) levels can reflect early lung function changes. METHODS: The cumulative respiratory dust exposure (CDE) levels of 1,461 coal miners were retrospectively assessed by constructed a job-exposure matrix to replace working years. Important factors affecting lung function and CC16 were selected by establishing random forest models. Subsequently, the potential of CC16 to reflect lung injury was explored from multiple perspectives. First, restricted cubic spline (RCS) models were used to compare the trends of changes in lung function indicators and plasma CC16 levels after dust exposure. Then mediating analysis was performed to investigate the role of CC16 in the association between dust exposure and lung function decline. Finally, the association between baseline CC16 levels and follow-up lung function was explored. RESULTS: The median CDE were 35.13 mg/m³-years. RCS models revealed a rapid decline in forced vital capacity (FVC), forced expiratory volume in the first second (FEV₁), and their percentages of predicted values when CDE exceeded 25 mg/m³-years. The dust exposure level (<5 mg/m³-years) causing significant changes in CC16 was much lower than the level (25 mg/m³-years) that caused changes in lung function indicators. CC16 mediated 11.1% to 26.0% of dust-related lung function decline. Additionally, workers with low baseline CC16 levels experienced greater reductions in lung function in the future. CONCLUSIONS CC16 levels are more sensitive than lung indicators in reflecting early lung function injury and plays mediating role in lung function decline induced by dust exposure. Low baseline CC16 levels predict poor future lung function.
Uteroglobin/blood* ; Humans ; Dust/analysis* ; Occupational Exposure/analysis* ; Male ; Middle Aged ; Adult ; Retrospective Studies ; Lung Injury/chemically induced* ; Coal Mining ; Biomarkers/blood* ; China/epidemiology* ; Air Pollutants, Occupational ; Female

Per- and polyfluoroalkyl substances (PFAS) have recently been shown to affect human health at low levels in the blood, according to epidemiological evidence. Consequently, human exposure to these chemicals should be strictly controlled to prevent health risks. This review reports on the potential sources of PFAS using Japan as an example. Tap water has attracted attention as a source of exposure to PFAS. PFAS have also been detected in the air, in household dust, and in consumer products. Furthermore, in the general population, diet is the most common source of exposure, and there is particular concern about human exposure to PFAS accumulated in seafood. Continuous monitoring is important for appropriate management of exposure for both humans and the environment.
Seafood/toxicity* ; Fluorocarbons/toxicity* ; Japan ; Drinking Water/standards* ; Air Pollutants/toxicity* ; Humans ; Dust/analysis* ; Environmental Exposure/standards* ; Food Contamination/analysis* ; Environmental Pollutants/toxicity* ; Water Pollutants, Chemical/toxicity*

OBJECTIVES: As early as the Apollo 11 mission, astronauts experienced ocular, skin, and upper airway irritation after lunar dust (LD) was brought into the return cabin, drawing attention to its potential biological toxicity. However, the biological effects of LD exposure through the digestive system remain poorly understood. This study aimed to evaluate the impact of digestive exposure to lunar dust simulant (LDS) on gut microbiota and on the intestine, liver, kidney, lung, and bone in mice. METHODS: Eight-week-old female C57BL/6J mice were used. LDS was used as a substitute for lunar dust, and Shaanxi loess was used as Earth dust (ED). Mice were randomly divided into a phosphate buffered saline (PBS) group, an ED group (500 mg/kg), and a LDS group (500 mg/kg), with assessments at days 7, 14, and 28. Mice were gavaged once every 3 days, with body weight recorded before each gavage. At sacrifice, fecal samples were analyzed by 16S ribosomal RNA (rRNA) sequencing; inflammatory cytokine expression [interleukin (IL)-1β, IL-6, and tumor necrosis factor alpha (TNF-α)] in intestinal, liver, and lung tissues was measured by real-time reverse transcription PCR (real-time RT-PCR); hematoxylin and eosin (HE) staining was performed on lung, liver, and intestinal tissues; Periodic acid-Schiff (PAS) staining was used to assess the integrity of the intestinal mucus barrier, and immunohistochemical staining was performed to evaluate the expression of mucin-2 (MUC2). Serum biochemical tests assessed hepatic and renal function. Femoral bone mass was analyzed by micro-computed tomography (micro-CT); osteoblasts and osteoclasts were assessed by osteocalcin (OCN) and tartrate-resistant acid phosphatase (TRAP) staining. Bone marrow immune cell subsets were analyzed by flow cytometry. RESULTS: At day 10, weight gain was slowed in ED and LDS groups. At days 22 and 28, body weight in both ED and LDS groups was significantly lower than controls (both P<0.05). LDS exposure increased microbial species richness and diversity at day 7. Compared with the PBS and ED groups, mice in the LDS group showed increased relative abundance of Deferribacterota, Desulfobacterota, and Campylobacterota, and decreased Firmicutes, with increased Helicobacter typhlonius and reduced Lactobacillus johnsonii and Lactobacillusmurinus. HE and PAS staining of the colon showed that mucosal structural disruption and goblet cell loss were more severe in the LDS group. In addition, immunohistochemistry revealed a significant downregulation of MUC2 expression in this group (P<0.05). No obvious pathological alterations were observed in liver HE staining among the 3 groups, and none of the groups exhibited notable hepatic or renal dysfunction. HE staining of the lungs in the ED and LDS groups showed increased perivascular inflammatory cell infiltration (both P<0.05). CONCLUSIONS LDS exposure via the digestive route induces gut dysbiosis, intestinal barrier disruption, pulmonary inflammation, bone loss, and bone marrow immune imbalance. These findings indicate that LD exposure poses potential health risks during future lunar missions. Targeted restoration of beneficial gut microbiota may represent a promising strategy to mitigate LD-related health hazards.
Animals ; Dust ; Mice ; Mice, Inbred C57BL ; Dysbiosis/etiology* ; Female ; Gastrointestinal Microbiome/drug effects* ; Moon ; Liver/metabolism* ; Digestive System/microbiology* ; Lung/metabolism* ; Kidney

OBJECTIVES: Due to prolonged exposure to cosmic radiation and meteorite impacts, lunar surface dust forms nanoscale angular particles with strong electrostatic adsorption properties. These dust particles pose potential inhalation risks, yet their pulmonary toxicological mechanisms remain unclear. Given the need for dust exposure protection in future lunar base construction and resource development, this study established an acute exposure model using lunar soil simulant (LSS) and used Earth soil (ES; Loess from Shaanxi, China) as a comparison to investigate lung injury mechanisms. METHODS: C57BL/6 mice were randomly assigned to 3 groups: Phosphate buffered saline (PBS), LSS, and ES, with 5 to 7 mice per group. Mice in the LSS and ES groups received a single intratracheal instillation to induce acute inhalation exposure. Body weight was monitored for 28 days. Mice were euthanized at days 3, 7, 14, and 28 post-exposure, and peripheral blood, bronchoalveolar lavage fluid (BALF), and lung tissues were collected. Immune cell subsets in BALF were analyzed using flow cytometry. Hematoxylin-eosin (HE) staining assessed lung structure and inflammation; periodic acid-Schiff (PAS) staining evaluated airway mucus secretion; Masson staining examined collagen deposition. Real-time reverse transcription PCR (real-time RT-PCR) was used to measure the mRNA expression of inflammatory cytokines (IL-1β, IL-6, and TNF-α) and epithelial barrier genes (Occludin, Cadherin-1, and Zo-1). Lung tissues at day 7 were subjected to transcriptomic sequencing, followed by immune infiltration and pathway enrichment analyses to determine immunoregulatory mechanisms. RESULTS: Body weight in the ES group progressively declined after day 18 (all P<0.05), while the LSS group showed no significant changes compared with the control group. HE staining showed both LSS and ES induced inflammatory cell infiltration around airways and vasculature, which persisted for 28 days but gradually lessened over time. PAS staining revealed marked mucus hypersecretion in the LSS group at day 3, followed by gradual recovery; no significant mucus changes were observed in the ES group. Masson staining indicated no obvious pulmonary fibrosis in either group within 28 days. Real-time RT-PCR demonstrated significant upregulation of IL-1β and TNF-α in both LSS and ES groups, peaking on day 7, accompanied by downregulation of epithelial barrier genes (Occludin, Cadherin-1, and Zo-1)(all P<0.05). Transcriptomic analysis showed that both LSS and ES activated chemokine-related pathways and enriched leukocyte migration and neutrophil recruitment pathways. Further validation revealed upregulation of CXCL2 and MMP12 in the LSS group, whereas CXCL3 and MMP12 were predominantly elevated in the ES group. CONCLUSIONS Both LSS and ES can induce sustained lung injury and neutrophil infiltration in mice, though the underlying molecular mechanisms differ. Compared with ES, exposure to LSS additionally triggers a transient eosinophilic response, suggesting that lunar dust particles possess stronger immunostimulatory potential and higher biological toxicity.
Animals ; Mice ; Mice, Inbred C57BL ; Soil ; Lung Injury/etiology* ; Dust ; Bronchoalveolar Lavage Fluid ; Moon ; Lung/pathology* ; Inhalation Exposure/adverse effects* ; Male

To investigate the common specific immunoglobulin E(sIgE) in children with eczema and urticaria, compare the allergies in children with different diseases, genders and ages, and provide the scientific basis for the prevention, diagnosis and treatment. A retrospective study was conducted to analyze the children who were suspected of eczema and urticaria and tested for serum sIgE in the Tianjin Children's Hospital from December 2019 to August 2021. A total of 8 092 serum samples were tested for ten food allergens and ten inhaled allergens. The method was the enzyme-linked immune capture assay. The allergen epidemiological characteristics were statistically analyzed by Chi square test based on the children's characteristics and factors such as different sexes and ages and by the mass data. The results showed that the positive rate of eczema was 64.42%(5 213/8 092), and the urticaria was 35.58%(2 879/8 092). The positive rate of specific IgE was 66.65%(5 393/8 092), the food allergens was 61.74%(4 996/8 092), and the inhaled allergens was 34.85%(2 820/8 092). The top three positive rates of food allergens were egg 46.65%(3 775/8 092), milk 32.64%(2 641/8 092) and wheat flour 15.08%(1 220/8 092). The top three positive rates of inhaled allergens were house dust 21.40%(1 732/8 092), Alternaria 11.78%(953/8 092) and Dermatophagoides farinae 7.33%(593/8 092). The positivity of food allergens and inhaled allergens was significantly different in different age groups. The positive rates of food allergens in different age groups were 48.92%(947/1 936) in<1 year old, 72.28%(2 680/3 708) in 1-3 years old, 64.58%(919/1 423) in 4-6 years old and 43.90%(450/1 025) in>6 years old. The positive rates of inhaled allergens in different age groups were 17.67%(342/1 936) in<1 year old, 36.35%(1 348/3 708) in 1-3 years old, 46.38%(660/1 423) in 4-6 years old and 45.85%(470/1 025) in>6 years old. The top six positive rates of allergens of eczema were the same with urticaria, which were egg, milk, house dust, wheat flour, Alternaria and Dermatophagoides farinae. The allergens (greater than or equal to grade 4) differed in children with eczema and urticaria. Moreover, there were significant differences in the positive rates of Alternaria, egg, wheat flour, crab and shrimp. In conclusion, this study can reflect the epidemic characteristics of allergens in children with eczema and urticaria to a certain extent. There were significant differences in the positive rates of allergens between different age groups. It is necessary to reasonably avoid the high-risk allergens according to the epidemiological characteristics and clinical symptoms, which provide valuable information for the prevention, diagnosis and treatment of allergic diseases.
Infant ; Child ; Humans ; Female ; Male ; Child, Preschool ; Flour ; Retrospective Studies ; Triticum ; Urticaria/epidemiology* ; Eczema/epidemiology* ; Hospitals ; Immunoglobulin E ; Allergens ; Dust

Objective: To investigate the chronic respiratory symptoms and pulmonary function of adult residents in 3 towns of Hongtong County, Shanxi Province, and to explore their risk factors. Methods: The investigation of chronic respiratory symptoms and lung function status of adult residents in Hongdong County is based on the regional population of the entire county in Hongdong County. The project was initiated by the Science and Technology Department of Linfen City and coordinated by the Hongdong County Government. The investigation will be conducted in 3 townships in Hongdong County, Linfen City, Shanxi Province from April to November 2021: Demographic characteristics, respiratory symptoms, smoking dust exposure and other personal history were collected through questionnaires. Physical examination, routine blood tests and lung function tests were also performed on each individual. SPSS 22.0 software was used to conduct t test, χ² test, ANOVA or Kruskal-Wallis test for statistical analysis of the collected information. Results: 10 945 subjects aged 18-102 years were included in the analysis, of whom 3 754 (34.3%) were male, 1 222 (11.2%) had a history of dust exposure, 7 164 (65.5%) had used straw and firewood as cooking fuel, and 3 296 (30.1%) had a history of smoking. Among the participants, 394 (3.6%), 339 (3.1%), and 1 543 (14.1%) had respiratory symptoms such as chronic cough, sputum, and dyspnea. Statistics showed that the population with chronic respiratory symptoms was more elderly and had a smoking history, and the incidence of chronic respiratory symptoms was higher in those who smoked more than 40 packs a year (all P<0.05). Men with a history of dust exposure were more likely to suffer from chronic cough and expectoration, while emaciation and biofuel use for more than 40 years were more likely to suffer from chronic expectoration and dyspnea (all P<0.05). The median values of forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC) and FEV1/FVC in 1 second were 2.19 L/s, 3.24 L and 69.16%, respectively. Among them, the lung function of 5 801 (53.0%) respondents was lower than the expected value. The median FEV1/FVC decreased with the increase of age. The FEV1/FVC of people over 40 years old with smoking history was lower, the dust exposure history of people with decreased lung function was more than that of people with normal lung function, and the incidence of chronic expectoration and dyspnea was higher in people with decreased lung function (all P<0.05). The absolute value and ratio of eosinophils in patients with decreased ventilation function over 60 years old were significantly higher than those with normal ventilation function, but the level of body mass index (BMI) was lower (all P<0.05). Conclusion: In Hongdong County, Shanxi Province, grassroots residents have poor medical awareness, low lung function examination rate, chronic respiratory symptoms and lung function decline are associated with more risk factors. Primary medical institutions need to formulate prevention strategies and carry out lung function detection according to the actual situation, focusing on monitoring and follow-up of high-risk groups to achieve early and timely prevention, diagnosis and treatment of chronic obstructive pulmonary disease.
Aged ; Adult ; Humans ; Male ; Middle Aged ; Female ; Cough/epidemiology* ; Lung ; Pulmonary Disease, Chronic Obstructive/epidemiology* ; Chronic Disease ; Lung Diseases ; Vital Capacity ; Dyspnea ; Dust/analysis* ; Forced Expiratory Volume

Objective: To investigate the clinicopathological characteristics of occupational lung diseases, to reduce the missed diagnoses and misdiagnoses of the diseases and to help standardize the diagnosis and treatment of these patients. Methods: A total of 4 813 lung biopsy specimens (including 1 935 consultation cases) collected at the Department of Pathology, Nanjing Drum Tower Hospital, Nanjing, China from January 1st, 2017 to December 31th, 2019 were retrospectively analyzed. Among them, 126 cases of occupational lung diseases were confirmed with clinical-radiological-pathological diagnosis. Special staining, PCR and scanning electron microscopy were also used to rule out the major differential diagnoses. Results: The 126 patients with occupational lung diseases included 102 males and 24 females. All of them had a history of exposure to occupational risk factor(s). Morphologically, 68.3% (86/126) of the cases mainly showed pulmonary fibrotic nodules, dust plaque formation or carbon end deposition in pulmonary parenchyma. 16.7% (21/126) of the cases mainly showed welding smoke particle deposition in the alveolar cavity and lung interstitium while 15.1% (19/126) of the cases showed granulomas with fibrous tissue hyperplasia, alveolar protein deposition or giant cell interstitial pneumonia. The qualitative and semi-quantitative analyses of residual dust components in the lung under scanning electron microscope were helpful for the diagnosis of welder's pneumoconiosis and hard metal lung disease. Conclusions: The morphological characteristics of lung biopsy tissue are important reference basis for the clinicopathological diagnosis and differential diagnosis of occupational lung diseases. Recognizing the characteristic morphology and proper use of auxiliary examination are the key to an accurate diagnosis of occupational lung diseases on biopsy specimens.
Male ; Female ; Humans ; Retrospective Studies ; Pneumoconiosis/pathology* ; Lung/pathology* ; Dust ; Pneumonia, Viral/pathology* ; Biopsy

To investigate the common specific immunoglobulin E(sIgE) in children with eczema and urticaria, compare the allergies in children with different diseases, genders and ages, and provide the scientific basis for the prevention, diagnosis and treatment. A retrospective study was conducted to analyze the children who were suspected of eczema and urticaria and tested for serum sIgE in the Tianjin Children's Hospital from December 2019 to August 2021. A total of 8 092 serum samples were tested for ten food allergens and ten inhaled allergens. The method was the enzyme-linked immune capture assay. The allergen epidemiological characteristics were statistically analyzed by Chi square test based on the children's characteristics and factors such as different sexes and ages and by the mass data. The results showed that the positive rate of eczema was 64.42%(5 213/8 092), and the urticaria was 35.58%(2 879/8 092). The positive rate of specific IgE was 66.65%(5 393/8 092), the food allergens was 61.74%(4 996/8 092), and the inhaled allergens was 34.85%(2 820/8 092). The top three positive rates of food allergens were egg 46.65%(3 775/8 092), milk 32.64%(2 641/8 092) and wheat flour 15.08%(1 220/8 092). The top three positive rates of inhaled allergens were house dust 21.40%(1 732/8 092), Alternaria 11.78%(953/8 092) and Dermatophagoides farinae 7.33%(593/8 092). The positivity of food allergens and inhaled allergens was significantly different in different age groups. The positive rates of food allergens in different age groups were 48.92%(947/1 936) in<1 year old, 72.28%(2 680/3 708) in 1-3 years old, 64.58%(919/1 423) in 4-6 years old and 43.90%(450/1 025) in>6 years old. The positive rates of inhaled allergens in different age groups were 17.67%(342/1 936) in<1 year old, 36.35%(1 348/3 708) in 1-3 years old, 46.38%(660/1 423) in 4-6 years old and 45.85%(470/1 025) in>6 years old. The top six positive rates of allergens of eczema were the same with urticaria, which were egg, milk, house dust, wheat flour, Alternaria and Dermatophagoides farinae. The allergens (greater than or equal to grade 4) differed in children with eczema and urticaria. Moreover, there were significant differences in the positive rates of Alternaria, egg, wheat flour, crab and shrimp. In conclusion, this study can reflect the epidemic characteristics of allergens in children with eczema and urticaria to a certain extent. There were significant differences in the positive rates of allergens between different age groups. It is necessary to reasonably avoid the high-risk allergens according to the epidemiological characteristics and clinical symptoms, which provide valuable information for the prevention, diagnosis and treatment of allergic diseases.
Infant ; Child ; Humans ; Female ; Male ; Child, Preschool ; Flour ; Retrospective Studies ; Triticum ; Urticaria/epidemiology* ; Eczema/epidemiology* ; Hospitals ; Immunoglobulin E ; Allergens ; Dust

Objective: To investigate the chronic respiratory symptoms and pulmonary function of adult residents in 3 towns of Hongtong County, Shanxi Province, and to explore their risk factors. Methods: The investigation of chronic respiratory symptoms and lung function status of adult residents in Hongdong County is based on the regional population of the entire county in Hongdong County. The project was initiated by the Science and Technology Department of Linfen City and coordinated by the Hongdong County Government. The investigation will be conducted in 3 townships in Hongdong County, Linfen City, Shanxi Province from April to November 2021: Demographic characteristics, respiratory symptoms, smoking dust exposure and other personal history were collected through questionnaires. Physical examination, routine blood tests and lung function tests were also performed on each individual. SPSS 22.0 software was used to conduct t test, χ² test, ANOVA or Kruskal-Wallis test for statistical analysis of the collected information. Results: 10 945 subjects aged 18-102 years were included in the analysis, of whom 3 754 (34.3%) were male, 1 222 (11.2%) had a history of dust exposure, 7 164 (65.5%) had used straw and firewood as cooking fuel, and 3 296 (30.1%) had a history of smoking. Among the participants, 394 (3.6%), 339 (3.1%), and 1 543 (14.1%) had respiratory symptoms such as chronic cough, sputum, and dyspnea. Statistics showed that the population with chronic respiratory symptoms was more elderly and had a smoking history, and the incidence of chronic respiratory symptoms was higher in those who smoked more than 40 packs a year (all P<0.05). Men with a history of dust exposure were more likely to suffer from chronic cough and expectoration, while emaciation and biofuel use for more than 40 years were more likely to suffer from chronic expectoration and dyspnea (all P<0.05). The median values of forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC) and FEV1/FVC in 1 second were 2.19 L/s, 3.24 L and 69.16%, respectively. Among them, the lung function of 5 801 (53.0%) respondents was lower than the expected value. The median FEV1/FVC decreased with the increase of age. The FEV1/FVC of people over 40 years old with smoking history was lower, the dust exposure history of people with decreased lung function was more than that of people with normal lung function, and the incidence of chronic expectoration and dyspnea was higher in people with decreased lung function (all P<0.05). The absolute value and ratio of eosinophils in patients with decreased ventilation function over 60 years old were significantly higher than those with normal ventilation function, but the level of body mass index (BMI) was lower (all P<0.05). Conclusion: In Hongdong County, Shanxi Province, grassroots residents have poor medical awareness, low lung function examination rate, chronic respiratory symptoms and lung function decline are associated with more risk factors. Primary medical institutions need to formulate prevention strategies and carry out lung function detection according to the actual situation, focusing on monitoring and follow-up of high-risk groups to achieve early and timely prevention, diagnosis and treatment of chronic obstructive pulmonary disease.
Aged ; Adult ; Humans ; Male ; Middle Aged ; Female ; Cough/epidemiology* ; Lung ; Pulmonary Disease, Chronic Obstructive/epidemiology* ; Chronic Disease ; Lung Diseases ; Vital Capacity ; Dyspnea ; Dust/analysis* ; Forced Expiratory Volume

Objective: Differential flora and differential metabolites shared by the intestinal and respiratory tracts of rats were screened to analyze the possible role of changes in intestinal flora and metabolites in the progression of pneumoconiosis in rats. Methods: In April 2020, 18 SD rats were randomly divided into three groups (control group, coal mine dust group and silica group, 6 in each group) , rats in the coal mine dust group and silica group were perfused with 1 ml of 50 mg/ml coal mine well dust suspension and silica suspension by nontracheal exposure, respectively. While rats in the control group were perfused with an equal dose of sterilized normal saline. Twenty four weeks after dust staining, rat feces, throat swabs, and lung lavages were collected. 16SrDNA gene sequencing and UHPLC-QTOF-MS untargeted metabolomics were used to analyze the flora and metabolites in feces, throat swabs and lung lavage fluid of rats in each group, to screen for shared differential flora and shared differential metabolites in intestinal and respiratory tract, and the correlation analysis between the differential flora and metabolites was performed using Spearman's statistics. Results: Compared with the control group, a total of 9 species shared differential flora between intestinal and respiratory tract were screened at phylum level, and a total of 9 species shared differential genus between intestinal and respiratory tract were screened at genus level in the coal mine dust group, mainly Firmicutes, Actinobacteria, Streptococcus, Lactobacillus, etc. Compared with the control group, a total of 9 shared differential flora were screened at the phylum level, and a total of 5 shared differential genus were screened at the genus level in the silica group, mainly Proteobacteria, Actinobacteria, Allobactera, Mucilaginibacter, etc. Compared with the control group, a total of 7 shared differential metabolites were screened for up-regulation of Stigmatellin, Linalool oxide and Isoleucine-leucine in both intestinal and respiratory tract in the coal mine dust group. Compared with the control group , a total of 19 shared differential metabolites werescreened in the silica group, of which Diethanolamine, 1-Aminocyclopropanecarboxylic acid, Isoleucine-leucine, Sphingosine, Palmitic acid, D-sphinganine, 1, 2-dioleoyl-sn-glycero-3-phosphatidylcholine, and 1-Stearoyl-2-oleoyl-sn-glycerol 3-phosphocholine were up-regulated in both the intestinal and respiratory tract. Conclusion: There is a translocation of intestinal and respiratory flora in pneumoconiosis rats, and rats have an imbalance of lipid metabolism during the progression of pneumoconiosis.
Rats ; Animals ; Isoleucine ; Leucine ; Coal Mining ; Rats, Sprague-Dawley ; Pneumoconiosis ; Dust/analysis* ; Silicon Dioxide ; Coal