Cross-sectional analysis of dyslipidemia risk in coal mine workers: from epidemiology to animal models

OBJECTIVE

To investigate the association between coal dust exposure and the occurrence of dyslipidemia in coal mine workers, and identify relevant risk factors. Methods: We selected a population who underwent occupational health examinations at Huainan Yangguang Xinkang Hospital from March 2020 to July 2022. Participants were divided into two groups based on the presence or absence of dyslipidemia, and their baseline information was collected, including records of coal dust exposure. We employed single-factor analysis to identify risk factors for dyslipidemia and adjusted for confounding factors in the adjusted models. Additionally, we explored the effects in different populations using stratified analysis, smooth curve fitting, and propensity score matching. Finally, we confirmed the causal relationship between coal dust exposure and dyslipidemia by examining tissue sections and lipid-related indicators in a mouse model of coal dust exposure. Results A total of 5,657 workers were included in the study, among whom 924 individuals had dyslipidemia and 4,743 individuals did not have dyslipidemia. The results of the single-factor analysis revealed that dust exposure, age, BMI, blood pressure, and smoking were statistically significant risk factors for dyslipidemia (p < 0.05). Additionally, the three multivariate models, adjusted for different confounders, consistently showed a significant increase in the risk of dyslipidemia associated with coal dust exposure (Model 1: OR, 1.869; Model 2: OR, 1.863; Model 3: OR, 2.033). After conducting stratified analysis, this positive correlation remained significant. Furthermore, propensity score matching analysis revealed that with increasing years of work, the risk of dyslipidemia gradually increased, reaching 50% at 11 years. In the mouse model of coal dust exposure, significant coal dust deposition was observed in the lungs and livers of the mice, accompanied by elevated levels of total cholesterol (TC), alanine transaminase (ALT), aspartate transaminase (AST), and low-density lipoprotein cholesterol (LDL-C). Conclusion Exposure to coal dust significantly increases the risk of developing dyslipidemia, and this positive correlation exists in different populations, particularly with increasing years of work, resulting in a higher risk.

Erythrocyte glutathione transferase. A sensitive Up-Down biomarker of environmental and industrial pollution

Erythrocyte glutathione transferase is a well-known biomarker of environmental pollution. Examination of the extensive scientific literature discovers an atypical and very interesting property of this enzyme which may reveal a chronic exposition to many contaminants but in some cases even an acute and short-term dangerous contamination. This review also underlines the peculiar molecular and kinetic properties of this enzyme which makes it unique in the panorama of enzymes used as biomarker for environmental contamination.

Coal Dust-Induced Systematic Hypoxia and Redox Imbalance among Coal Mine Workers

Continuous inhalation of coal dust among coal workers leads to a variety of disorders. The present study aims to evaluate the potential oxidative stress associated with coal dust generated from coal mining activities among exposed workers through the antioxidant enzyme system, including superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH). In this study cohort, intensive coal mine workers were assessed for antioxidant variations. Blood samples were collected from dust-exposed workers (engaged in different activities at coal mines; n = 311) and residents of the same city (nonexposed, control group; n = 50). The workers' exposure to coal dust was categorized based on working area (administrative group, surface workers, underground workers), working hours (up to 8 h and more than 8 h), and time of service. The results showed significantly altered activities of SOD, CAT, and GSH among the whole exposed group and its categories compared to the control group. A significant difference was also observed between high- and low-exposure groups. Statistical analysis revealed a negative correlation between antioxidant activity (catalase and SOD) and coal dust levels. Besides, coal exposure was associated with the time of service, smoking status, and dietary habits. The findings of this study reveal higher oxidative stress among highly exposed coal mine workers (underground workers > surface workers > administrative group > nonexposed group), and longer working hours have more pronounced adverse effects on workers' health.

Association between weather seasonality and blood parameters in riverine populations of the Brazilian Amazon

OBJECTIVE

To analyze the seasonality of blood parameters related to iron homeostasis, inflammation, and allergy in two riverine populations from the Brazilian Amazon.

METHODS

This was a cross-sectional study of 120 children and adolescents of school age, living in riverine communities of Porto Velho, Rondonia, Brazil, describing the hematocrit, hemoglobin, ferritin, serum iron, total white blood cell count, lymphocytes, eosinophils, C-reactive protein, and immunoglobulin E levels in the dry and rainy seasons. The chi-squared test and the prevalence ratio were used for the comparison of proportions and mean analysis using paired Student's t-test.

RESULTS

Hemoglobin (13.3g/dL) and hematocrit (40.9%) showed higher average values in the dry season. Anemia prevalence was approximately 4% and 12% in the dry and rainy seasons, respectively. Serum iron was lower in the dry season, with a mean of 68.7 mcg/dL. The prevalence of iron deficiency was 25.8% in the dry season and 9.2% in the rainy season. Serum ferritin did not show abnormal values in both seasons; however, the mean values were higher in the dry season (48.5ng/mL). The parameters of eosinophils, lymphocytes, global leukocyte count, C-reactive protein and immunoglobulin E showed no seasonal differences. C-reactive protein and immunoglobulin E showed abnormal values in approximately 7% and 60% of the examinations, respectively.

CONCLUSION

Hematological parameters of the red cell series and blood iron homeostasis had seasonal variation, which coincided with the dry season in the region, in which an increase in atmospheric pollutants derived from fires is observed.

Anthocyanin-rich extract from Hibiscus sabdariffa calyx counteracts UVC-caused impairments in rats

CONTEXT

Ultraviolet radiation (UV) was reported to cause oxidative stress. Hibiscus sabdariffa L. (Malvaceae) calyx is commonly used in traditional Asian and African medicines and possesses strong antioxidant capacity due to its anthocyanin (ANTH) content.

OBJECTIVE

This study researched the possible protective role of Hibiscus sabdariffa calyx extract (HSCE) in UVC exposure of rats.

MATERIAL AND METHODS

Levels of serum enzymes, renal function tests, and some oxidant/antioxidant biomarkers of skin, lens, and retina tissues were monitored. Rats were exposed to UVC 4 h daily for 40 d and simultaneously received HSCE containing 2.5, 5, and 10 mg doses of ANTH in drinking water.

RESULTS

Significant (p < 0.05) increases in the levels of serum aminotransferases, lactate dehydrogenase, urea, creatinine, and uric acid were noted after UVC exposure. In skin, lens, and retina tissues, total oxidant status, oxidative stress index, lipid peroxidation, and protein oxidation escalated markedly (p < 0.05) whereas total antioxidant status, reduced glutathione, and superoxide dismutase decreased dramatically (p < 0.05) related to UVC. Co-administration of HSCE with each ANTH dose significantly (p < 0.05) reversed aforementioned parameters (except total oxidant status) almost in all tissues. The LD50 of HSCE in rats was determined to be above 5000 mg/kg.

DISCUSSION AND CONCLUSION

Our data revealed that HSCE has a remarkable potential to counteract UVC-caused impairments, probably through its antioxidant and free radical-defusing effects. Therefore, HSCE could be useful against some cutaneous and ocular diseases in which UV and oxidative stress have a role in the etiopathogenesis.

Altered gene expression in HepG2 cells exposed to a methanolic coal dust extract

Exposure to coal dust has been associated with different chronic diseases and mortality risk. This airborne pollutant is produced during coal mining and transport activities, generating environmental and human toxicity. The aim of this study was to determine the effects of a coal dust methanolic extract on HepG2, a human liver hepatocellular carcinoma cell line. Cells were exposed to 5-100ppm methanolic coal extract for 12h, using DMSO as control. MTT and comet assays were used for the evaluation of cytotoxicity and genotoxicity, respectively. Real time PCR was utilized to quantify relative expression of genes related to oxidative stress, xenobiotic metabolism and DNA damage. Coal extract concentrations did not induce significant changes in HepG2 cell viability after 12h exposure; however, 50 and 100ppm of the coal extract produced a significant increase in genetic damage index with respect to negative control. Compared to vehicle control, mRNA CYP1A1 (up to 163-fold), NQO1 (up to 4.7-fold), and GADD45B (up to 4.7-fold) were up regulated, whereas PRDX1, SOD, CAT, GPX1, XPA, ERCC1 and APEX1 remained unaltered. This expression profile suggests that cells exposed to coal dust extract shows aryl hydrocarbon receptor-mediated alterations, changes in cellular oxidative status, and genotoxic effects. These findings share some similarities with those observed in liver of mice captured near coal mining areas, and add evidence that living around these industrial operations may be negatively impacting the biota and human health.