Genetic susceptibility in pneumoconiosis

Anomalous Enrichment of As and Hg in Underground Coal Dust: A Case from Xishan Coalfield, Shanxi Province, North China

Coal dust is an important source of coal workers' pneumoconiosis, which is harmful to the health of underground workers. The coal dust samples were directly collected using a coal dust sampler from four major production positions in the underground coal mine. The particle size distribution, mineralogy, and occurrence of As and Hg in the coal dust samples were investigated. The results indicated that the contents of As and Hg were depleted or normal in the parent coal samples compared with the average values of C-P coal in North China and Chinese coal, but they were anomalously enriched in coal dusts. The concentrations of As and Hg in the coal dust samples studied are greater than the values of the elements in the parent coal. The As content in the coal dust samples studied is about one to three orders of magnitude above the parent coal value and the Hg content in the studied coal is 1.28 to 20.28 times higher than the parent coal value. The modes of occurrences of As and Hg were studied by sequential chemical extraction in combination with field emission scanning electron microscopy-energy dispersive spectroscopy (FESEM-EDS) and high-resolution transmission electron microscopy-EDS (HRTEM-EDS). The occurrence of As is dominated mainly by pyrite and secondarily by carbonate and silicate in the coal dust samples. Pyritic Hg and organic Hg may be the dominant forms in mining face and heading face samples, and carbonate and pyritic Hg are the main forms in rocks roadway and return airway samples. It is considered that the mechanochemical effect resulted in the formation of surface active sites and modification of the morphology. Harmful trace elements, such as As, Cd, Hg, Se, Pb, Co, Sb, and Tl, and minor grains associated with nanominerals that bear much hazardous elements, could easily be originally fractionated or adsorbed by airborne particulates. This research aims to provide a theoretical basis for the prevention of occupational disease and underground environmental evaluation.

Transcriptome-wide association study identifies PSMB9 as a susceptibility gene for coal workers' pneumoconiosis

Coal workers' pneumoconiosis (CWP) is a type of typical occupational lung disease caused by prolonged inhalation of coal mine dust. The individuals' different genetic background may underlie their different susceptibility to develop pneumoconiosis, even under the same exposure level. This study aimed to identify susceptibility genes associated with CWP. Based on our previous genome-wide association study (GWAS, 202 CWP cases vs. 198 controls) and gene expression data obtained by analyzing human lungs and whole blood from the Genotype-Tissue Expression (GTEx) Portal, a transcriptome-wide association study (TWAS) was applied to identify CWP risk-related genes. Luciferase report gene assay, qRT-PCR, Western blot, immunofluorescence assay, and TUNEL assay were conducted to explore the potential role of the candidate gene in CWP. Proteasome 20S subunit beta 9 (PSMB9) was identified as a strong risk-related gene of CWP in both lungs and whole blood (Lungs: P_TWAS  = 4.22 × 10^-4 ; Whole blood: P_TWAS  = 2.11 × 10^-4 ). Single nucleotide polymorphisms (SNPs) rs2071480 and rs1351383, which locate in the promoter region and the first intron of the PSMB9 gene, were in high linkage disequilibrium (LD, r²  = 0.98) with the best GWAS SNP rs4713600 (G>T, OR = 0.55, 95% CI: 0.42-0.74, P = 6.86 × 10^-5 ). Both rs2071480 and rs1351383 significantly enhanced the transcriptional activity of PSMB9. Functional experiments revealed that silica exposure remarkably reduced the PSMB9 expression and caused cell apoptosis, while overexpression of PSMB9 markedly abolished silica-induced cell apoptosis. We here identified PSMB9 as a novel susceptibility gene for CWP and provided important insights into the further exploration of the CWP pathogenesis.

Associations of VDR gene polymorphisms with risk of coal workers' pneumoconiosis in Chinese Han population

Some studies showed that the polymorphisms of vitamin D receptor (VDR) gene were associated with pulmonary diseases. However, the relationship between the VDR variations and susceptibility to coal worker's pneumoconiosis (CWP) remains unclear. The study aimed to determine the associations between VDR polymorphisms and susceptibility to CWP in Chinese Han population. The study involved 340 CWP patients and 312 healthy controls. The VDR polymorphisms were determined by DNA sequencing, and serum 25(OH)2D levels were detected by Ultra High-Performance Liquid Chromatography-Tandem Mass Spectrometry. The results showed that the VDR gene ApaI T allele increased the risk of CWP (OR = 1.486, 95% CI = 1.125-1.963, P = 0.006) and ApaI GT genotype as well as TT genotype increased the risk of CWP (GT vs. GG, OR = 1.461, 95% CI = 1.048-2.038, P = 0.025; TT vs. GG, OR = 2.673, 95% CI = 1.017-7.025, P = 0.039). Five haplotypes were identified and we found that the TGGT haplotype was associated with a lower risk of CWP (OR = 0.755, 95% CI = 0.603-0.946, P = 0.014). Meanwhile, multifactor dimensionality reduction analysis showed that the interaction between ApaI and exposure was the strongest, followed by TaqI and then BsmI. The study also found that the serum 25(OH)2D mean levels of the case group were significantly lower than that of the control group, and the serum 25(OH)2D mean levels of ApaI homozygous mutant and heterozygous mutant subjects were lower than that of the wild homozygosity, respectively (P < 0.001). The results suggested that ApaI T allele and GT or TT genotype and lower 25(OH)2D levels were increased the risk of CWP in Chinese Han population.

Associations of HMGB1 gene polymorphisms with risk of coal workers' pneumoconiosis susceptibility in Chinese Han population

Background: High-mobility group box 1 (HMGB1) protein plays an important pathogenic role in various diseases such as pulmonary fibrosis. However, the relationship between variation of HMGB1 gene and susceptibility to coal worker's pneumoconiosis (CWP) remains unclear. The objective of the study was to determine the association between HMGB1 polymorphisms and CWP in Chinese Han population.Methods: The genotypes of HMGB1 gene rs1045411, rs2249825, rs1412125 and rs1360485 in 340 CWP patients and 312 healthy controls were determined and serum HMGB1 levels were detected.Results: Our finding showed that the HMGB1 rs1360485 G allele increased the risk of CWP in comparison with A allele (P = 0.005). HMGB1 rs1360485 GG genotype as well as AG+GG genotype increased the risk of CWP in comparison with AA genotype (P = 0.010, P = 0.025, respectively). Four haplotypes were identified and we found that the GCTA haplotype was associated with resistance to CWP (P = 0.005), while GCTG haplotype was associated with risk to CWP (P<0.001). Meanwhile, multifactor dimensionality reduction (MDR) analysis showed that the interaction between rs1360485 and exposure had the strongest, followed by rs2249825 and rs1412125. This study also found that the serum HMGB1 levels of the case group were significantly higher than that of the control group, and the serum HMGB1 levels of homozygous subjects with rs1360485 mutant were higher than that of the heterozygous wild type, respectively (P<0.001). Meanwhile, the levels of HMGB1 with GCTA haplotype was lower than with GCTG haplotype (P<0.001)Conclusion: Our findings indicated that HMGB1 gene rs1360485 polymorphism was associated with the susceptibility to CWP in Chinese Han population.

miRNA sequencing reveals miRNA-4508 from peripheral blood lymphocytes as potential diagnostic biomarker for silica-related pulmonary fibrosis: A multistage study

BACKGROUND AND OBJECTIVE

This study aimed to identify miRNA as potential diagnostic biomarkers for silica-related pulmonary fibrosis (SPF).

METHODS

We first performed a comprehensive miRNA-seq screening in PBL of eight subjects exposed to silica dust (four individuals with SPF and four healthy controls). The promising miRNA were then evaluated in the first-stage validation using an independent GEO data set (GSE80555) of 6 subjects (3 individuals with SPF and 3 healthy controls), followed by a second-stage validation using 120 subjects exposed to silica dust (60 individuals with SPF and 60 healthy controls).

RESULTS

Thirty-five miRNA showed strong expression differences in miRNA-seq screening, while miRNA-4508 (P = 9.52 × 10^-3 ) was retained as a candidate after the first-stage validation (GSE80555), which was further confirmed in the second-stage validation with similar and strong effect (P = 9.93 × 10^-17 ). ROC analysis showed that miRNA-4508 could distinguish SPF cases from healthy controls with high AUC (0.886), with sensitivity of 81.7% and specificity of 86.7%. In addition, the miRNA-4508 upstream rs6576457 mutant A allele exhibited a strong association with susceptibility to SPF (OR = 1.64, 95% CI = 1.20-2.23, P = 0.002), while eQTL analysis revealed a potential association between different genotypes of rs6576457 and miRNA-4508 expression (P = 0.068) in 60 healthy subjects with silica dust exposure.

CONCLUSION

miRNA-4508 may be a potential diagnostic marker for SPF, and rs6576457, a functional variant of miRNA-4508, may affect SPF susceptibility. The detailed mechanism of action of this miRNA remains to be elucidated.

Dust induces lung fibrosis through dysregulated DNA methylation

Pneumoconiosis is a serious occupational disease that often occurs to coal workers with no early diagnosis and effective treatment at present. Diffuse pulmonary fibrosis is the major pathological change of pneumoconiosis, and its mechanism is still unclear. Epigenetics is involved in the development of many diseases, and it is closely associated with fibrosis. In this study, we investigated whether DNA methylation contributes to the pathogenesis of pulmonary fibrosis in pneumoconiosis. By exposure to coal dust or silica dust, we established the models of coal worker's pneumoconiosis (CWP), which showed an increased expression of COL-I, COL-III. We further found that DNMT1, DNMT3a, DNMT3b, MBD2, MeCP2 protein expression changed. Pretreatment with DNMT inhibitor 5-aza-dC reduced expression of COL-I, COL-III, and reduced pulmonary fibrosis. In summary, our results showed that DNA methylation contributes to dust-induced pulmonary fibrosis and that it may serve as a theoretical basis for testing DNA methyltransferase inhibitors in the treatment of CWP.

Functional variant of the carboxypeptidase M (CPM) gene may affect silica-related pneumoconiosis susceptibility by its expression: a multistage case-control study

Objectives

In a genome-wide association study, we discovered chromosome 12q15 (defined as rs73329476) as a silica-related pneumoconiosis susceptibility region. However, the causal variants in this region have not yet been reported.

Methods

We systematically screened eight potentially functional single-neucleotide polymorphism (SNPs) in the genes near rs73329476 (carboxypeptidase M (CPM) and cleavage and polyadenylation specific factor 6 (CPSF6)) in a case–control study including 177 cases with silicosis and 204 healthy controls, matched to cases with years of silica dust exposure. We evaluated the associations between these eight SNPs and the development of silicosis. Luciferase reporter gene assays were performed to test the effects of selected SNP on the activity of CPM in the promoter. In addition, a two-stage case–control study was performed to investigate the expression differences of the two genes in peripheral blood leucocytes from a total of 64 cases with silicosis and 64 healthy controls with similar years of silica dust exposure as the cases.

Results

We found a strong association between the mutant rs12812500 G allele and the susceptibility of silicosis (OR=1.45, 95% CI 1.03 to 2.04, p=0.034), while luciferase reporter gene assays indicated that the mutant G allele of rs12812500 is strongly associated with increased luciferase levels compared with the wild-type C allele (p<0.01). Moreover, the mRNA (peripheral blood leucocytes) expression of the CPM gene was significantly higher in subjects with silicosis compared with healthy controls.

Conclusions

The rs12812500 variant of the CPM gene may increase silicosis susceptibility by affecting the expression of CPM, which may contribute to silicosis susceptibility with biological plausibility.

Evaluation of the exposure to coal dust and prevalence of pneumoconiosis in underground mining in three Colombian departments

Introduction: Coal workers’ pneumoconiosis is a chronic and irreversible disease representing a public health problem. Objective: To estimate the prevalence of pneumoconiosis and its associated factors among underground coal miners in the Colombian departments of Boyacá, Cundinamarca and Norte de Santander. Materials and methods: We conducted a cross-sectional study of 476 miners to measure the prevalence of pneumoconiosis and its associated factors such as coal dust and silica levels, as well as the occupational conditions. The medical assessment and a chest x-ray were performed according to the International Labor Organization criteria, along with spirometry and the identification of glutathione S-transferase and repair enzyme polymorphisms.The associations were explored using Cox regression models. Results: We performed a total of 479 environmental monitoring sessions in 31 companies and we evaluated 476 workers with 10 to 57 years of mining work experience. The prevalence of pneumoconiosis was 33.8% (95% CI: 27.0 - 41.3%). In the Cox multivariate regression model with a constant risk time, pneumoconiosis was significantly associated with working in medium-sized companies (PR=2.00, 95% CI: 0.995 - 2.690; p=0.052), the level of severe exposure to coal dust (PR=2.055, 95% CI: 1.043 - 4.048; p=0.038), and working in underground mining for 25 years or more (for those with 25.0-29.9 years: PR=2.199, 95% CI: 1.449 - 3.338; p=0.001). Conclusions: The prevalence of pneumoconiosis was very high and was found to be associated with severe exposure to coal dust, work exposure for 25 years or more and working in medium-sized enterprises

Genetic susceptibility to toxicologic lung responses among inbred mouse strains following exposure to carbon nanotubes and profiling of underlying gene networks

The risk of human exposure to fiber nanoparticles has risen in recent years due to increases in the manufacture and utilization of carbon nanotubes (CNTs). CNTs are present as airborne particulates in occupational settings and their hazard potential has been demonstrated in experimental lung exposure studies using inbred mouse strains. However, it is not known whether different inbred strains differ in lung responses to CNTs by virtue of their genetics. In this work, common inbred strains (BALB/c, C57Bl/6, DBA/2, and C3H/He) were exposed to CNTs via oropharyngeal aspiration and lung histology and bronchoalveolar lavage (BAL) samples were evaluated over 28days with the objective of evaluating sensitivity/resistance among strains. C57Bl/6 mice developed significantly more extensive type II pneumocyte (T2P) hyperplasia and alveolar infiltrate compared to DBA/2 mice, which were resistant. Surprisingly, DBA/2 but not C57Bl/6 mice were extremely sensitive to increases in leukocytes recovered in BAL fluid. Underlying global gene expression patterns in the two strains were compared using mRNA sequencing to investigate regulatory networks associated with the different effects. The impact of exposure on gene networks regulating various aspects of immune response and cell survival was limited in DBA/2 mice compared to C57Bl/6. Investigation of B6D2F1 (C57Bl/6×DBA/2 hybrid) mice demonstrated inheritance of sensitivity to CNT exposures in regard to toxicologic lung pathology and BAL leukocyte accumulations. These findings demonstrate a genetic basis of susceptibility to CNT particle exposures and both inform the use of inbred mouse models and suggest the likelihood of differences in genetic susceptibility among humans.

Association between SNPs at IL-17A and IL-17F and susceptibility to accelerated silicosis

The association between single nucleotide polymorphisms (SNPs) in the interleukin (IL)-17 gene and silicosis has been evaluated in different populations. The aim of the present study was to analyze the association between SNPs at IL-17A (−832A/G) and IL-17F (+7488A/G) and susceptibility to accelerated silicosis in the Iranian Kurdish population. We studied 48 patients with accelerated silicosis and 62 controls. Genomic DNA was isolated using the “salting out” method. PCR-RFLP was performed for all SNPs typing. The frequencies of A/A, A/G, and G/G genotypes at IL-17A (−832A/G) were 4 (8.33%), 23 (47.92%), and 21 (43.75%) in patients and 5 (8.06%), 35 (56.45%), and 22 (35.48%) in controls, respectively. The frequencies of A and G alleles at IL-17 (−832A/G) were 31 (32.29%) and 65 (67.71%) in patients, and 45 (36.29%) and 79 (63.71%) in the controls, respectively. The frequencies of A/A, A/G, and G/G genotypes at IL-17F (+7488A/G) were 1 (2.08%), 47 (97.92%), and 0 (0%) in patients, and 11 (17.74%), 51 (82.26%), and 0 (0%) in the controls, respectively. The frequencies of A and G alleles at IL-17F (+7488A/G) were 49 (51.04%) and 47 (48.96%) in patients, and 73 (58.87%) and 51 (41.13%) in the controls, respectively. IL-17F (+7488A/G) genotype was more frequent among the cases compared with controls (97.92% vs. 82.26%). The frequency of the IL-17F (+7488A/G) genotype was significantly greater in patients with accelerated silicosis (odds ratio = 10.13 95%; confidence interval = 1.2–81.5; p = 0.008). The IL-17F (+7488A/G) genotype revealed a significantly increased risk of accelerated silicosis ( p < 0.05). The IL-17F (+7488 G) allele was associated with an increased risk of accelerated silicosis, but in the case of the IL-17A (−832A/G) polymorphism, a significant association was not observed.

Association between Genetic Variants of Transforming Growth Factor-β1 and Susceptibility of Pneumoconiosis: A Meta-analysis

Background:

Transforming growth factor-beta 1 (TGF-β1) and gene variants have been extensively studied in various human diseases. For example, TGF-β1 polymorphisms were associated with fibrosis and pneumoconiosis, but the data remained controversial. The aim of this meta-analysis was to assess the association between TGF-β1 −509 C>T [rs1800469], +869 T>C [rs1800470], and +915 G>C [rs1800471] polymorphisms and pneumoconiosis.

Methods:

A comprehensive literature search was conducted through searching in PubMed, Embase, the Chinese Biomedical Database, and the Wei Pu (Chinese) Database by the end of April 2016. Eleven publications with 21 studies were included in this meta-analysis, covering a total of 4333 patients with pneumoconiosis and 3478 controls. Study quality was assessed, and heterogeneity and publication bias were measured. All statistical analyses were performed using STATA version 12.0 (StataCorp, College Station, TX, USA) software.

Results:

The data showed significant associations between TGF-β1 −509 C>T polymorphism and the risk of pneumoconiosis development (T vs. C, odds ratio [OR] = 1.35, 95% confidence interval [CI]: 1.00–1.81, P = 0.046); between TGF-β1 +915 G>C polymorphism and the pneumoconiosis risk (C vs. G, OR = 1.69, 95% CI: 1.19–2.40, P = 0.004; CG vs. GG, OR = 1.79, 95% CI: 1.23–2.60, P = 0.002; CC+CG vs. GG, OR = 1.80, 95% CI: 1.24–2.61, P = 0.002). In addition, the subgroup analysis of ethnicity versus pneumoconiosis types indicated a significant association of silicosis among Asian populations but not that of coal workers’ pneumoconiosis in Caucasian populations. In contrast, no significant association was exhibited between TGF-β1 +869 T>C polymorphism and risk of pneumoconiosis.

Conclusion:

The polymorphisms of both TGF-β1 −509 C>T and +915 G>C are associated with increased risk of pneumoconiosis.

A systematic review of occupational exposure to coal dust and the risk of interstitial lung diseases

Objective: Exposure to coal dust can cause interstitial lung disease (ILD), but whether this is due to pure coal or to the contents of quartz in coal is less clear. Here, we systematically reviewed the relation between 'pure coal' and ILD. Methods: In a systematic review based on PRISMA criteria 2945 articles were identified. Strict eligibility criteria, which evaluated the 'pure coal effect', led to the inclusion of only nine studies. Results: Among these nine studies six studies indicated an independent effect of the non-quartz part of coal on the development and progression of ILD, two did not demonstrate an effect and one was inconclusive. Conclusions: Although an independent effect of non-quartz coal dust on the development of ILD is supported, due to methodological limitations the evidence is limited and further evidence is needed.

Pneumoconiosis increases the risk of congestive heart failure: A nationwide population-based cohort study

The purpose of the study was to determine the relationship between pneumoconiosis and congestive heart failure (CHF).We collected data from the National Health Insurance Research Database in Taiwan. The study sample comprised 8923 patients with pneumoconiosis and 35,692 nonpneumoconiosis controls enrolled from 2000 to 2011. Patients were followed up until the end of 2011 to evaluate the incidence of CHF. The risk of CHF was analyzed using Cox proportional hazard regression models, and the analysis accounted for factors such as sex, age, comorbidities, and air pollutants (μg/m).The overall incidence of CHF was higher in the pneumoconiosis cohort (15.7 per 1000 person-y) than in the nonpneumoconiosis cohort (11.2 per 1000 person-y), with a crude hazard ratio (HR) of 1.40 (P < 0.001). The HR for CHF was 1.38-fold greater in the pneumoconiosis cohort than in the nonpneumoconiosis cohort (P < 0.001) after the model was adjusted for age, sex, various comorbidities, and air pollutants (μg/m). The relative risk for CHF in the sex-specific pneumoconiosis cohort compared with the nonpneumoconiosis cohort was significant for men (adjusted HR = 1.40, 95% confidence interval = 1.21-1.62, P < 0.001). The incidence density rates of CHF increased with age; pneumoconiosis patients had a higher relative risk of CHF for all age group.Patients with pneumoconiosis were at higher risk for developing CHF than patients in the nonpneumoconiosis cohort, particularly in cases with coexisting coronary artery disease, hypertension, and chronic obstructive pulmonary disease.

Gene-environment interaction from international cohorts: impact on development and evolution of occupational and environmental lung and airway disease

Environmental and occupational pulmonary diseases impose a substantial burden of morbidity and mortality on the global population. However, it has been long observed that only some of those who are exposed to pulmonary toxicants go on to develop disease; increasingly, it is being recognized that genetic differences may underlie some of this person-to-person variability. Studies performed throughout the globe are demonstrating important gene-environment interactions for diseases as diverse as chronic beryllium disease, coal workers' pneumoconiosis, silicosis, asbestosis, byssinosis, occupational asthma, and pollution-associated asthma. These findings have, in many instances, elucidated the pathogenesis of these highly complex diseases. At the same time, however, translation of this research into clinical practice has, for good reasons, proceeded slowly. No genetic test has yet emerged with sufficiently robust operating characteristics to be clearly useful or practicable in an occupational or environmental setting. In addition, occupational genetic testing raises serious ethical and policy concerns. Therefore, the primary objective must remain ensuring that the workplace and the environment are safe for all.

GITR promoter polymorphism contributes to risk of coal workers' pneumoconiosis: a case-control study from China

BACKGROUND

Glucocorticoid-induced tumor necrosis factor (TNF) receptor-related protein (GITR) mainly affects the functions of effector T cells and regulatory T cells thus it may influence various diseases. Coal workers' pneumoconiosis (CWP) is a serious occupational disease worldwide. In the present study, we examined the association between the functional polymorphisms in GITR and risk of CWP in a Chinese population.

METHODS

An association study analyzing three polymorphisms (rs3753348, rs2298213, and rs11466668) in GITR were performed in a case-control study including 693 patients with CWP and 690 controls. Genotyping was carried out by Taqman method.

RESULTS

The GITR rs3753348 GG/GC genotypes significantly enhanced the risk of CWP (adjusted OR=1.32, 95%CI=1.02-1.71), compared with the CC genotype, particularly among subgroups of long exposure years (adjusted OR=1.47, 95%CI=1.06-2.04) and non-smokers (adjusted OR=1.45, 95%CI=1.01-2.09). Moreover, the polymorphism was significantly associated with risk for CWP cases with stage II.

CONCLUSIONS

This is the first report revealing an association between the GITR rs3753348 polymorphism and CWP, and our results suggest that the GITR rs3753348 polymorphism may be involved in the development and susceptibility of CWP.

Pneumoconiosis and respiratory problems in dental laboratory technicians: analysis of 893 dental technicians

OBJECTIVES

To explore the rate of pneumoconiosis in dental technicians (DTP) and to evaluate the risk factors.

MATERIAL AND METHODS

Data of 893 dental technicians, who were admitted to our hospital in the period January 2007-May 2012, from 170 dental laboratories were retrospectively examined. Demographic data, respiratory symptoms, smoking status, work duration, working fields, exposure to sandblasting, physical examination findings, chest radiographs, pulmonary function tests and high-resolution computed tomography results were evaluated.

RESULTS

Dental technicians' pneumoconiosis rate was 10.1% among 893 cases. The disease was more common among males and in those exposed to sandblasting who had 77-fold higher risk of DTP. The highest profusion subcategory was 3/+ (according to the International Labour Organization (ILO) 2011 standards) and the large opacity rate was 13.3%.

CONCLUSIONS

To the best of our knowledge, it was the largest DTP case series (N = 893/90) in the literature in English. Health screenings should be performed regularly for the early diagnosis of pneumoconiosis, which is an important occupational disease for dental technicians.

Interleukin-18, interleukin-8, and CXCR2 and the risk of silicosis

Molecular mechanisms in the pathogenesis of silicosis are not fully understood. Exposure to crystalline silica leads to the activation of signaling pathways controlling the production and secretion of inflammatory mediators. Inflammatory cytokines are noted as important candidate genes for fibrotic lung diseases. Cytokines, chemokines, and variations of their genes have been associated with upregulation or downregulation of chronic inflammatory mediators. Variations in the interleukin (IL)-18, IL-8 and chemokine receptor CXCR2 genes are believed to influence the risk of silicosis in stone-grinding factory workers in Iran. Allele-specific oligonucleotide polymerase chain reaction (PCR) procedure was carried out for IL-18 −137 and IL-18 −607, meanwhile touchdown PCR was performed for IL-8 −251 and CXCR2 +1208 genotyping. Variation in genotypic and allelic frequencies was not statistically different among cases versus controls ( p > 0.05). These findings indicated for the first time that IL-18 −137, IL-18 −607, IL-8 −251, and CXCR2 +1208 are suggested not to influence the risk of silicosis in tested occupational group.

Loosening the bonds of restrictive lung disease

Find out about this common but lesser-known respiratory condition and how to help your patient.

Understanding the chemical properties of macerals and minerals in coal and its potential application for occupational lung disease prevention

Recent increases in oil price further strengthen the argument that coal and coal products will play an increasingly important role in fulfilling the energy needs of our society. Coal is an aggregate of heterogeneous substances composed of organic (macerals) and inorganic (minerals) materials. The objective of this review was to assess whether some chemical parameters in coal play a role in producing environmental health problems. Basic properties of coal--such as chemical forms of the organic materials, structure, compositions of minerals--vary from one coal mine region to another as well as from coals of different ranks. Most importantly, changes in chemical properties of coals due to exposure to air and humidity after mining--a dynamic process--significantly affect toxicity attributed to coal and environmental fate. Although coal is an extremely complex and heterogeneous material, the fundamental properties of coal responsible for environmental and adverse health problems are probably related to the same inducing components of coal. For instance, oxidation of pyrite (FeS2) in the coal forms iron sulfate and sulfuric acid, which produces occupational lung diseases (e.g., pneumoconiosis) and other environmental problems (e.g., acid mine drainage and acid rain). Calcite (CaCO3) contained in certain coals alters the end products of pyrite oxidation, which may make these coals less toxic to human inhalation and less hazardous to environmental pollution. Finally, knowledge gained on understanding of the chemical properties of coals is illustrated to apply for prediction of toxicity due to coal possibly before large-scale mining and prevention of occupational lung disease during mining.