Polycyclic aromatic hydrocarbons exposure was associated with microRNA differential expression and neurotransmitter changes: a cross-sectional study in coal miners

Exposure to polycyclic aromatic hydrocarbons (PAHs) may cause neurobehavioral changes. This study aimed to explore the underlying mechanism of PAH neurotoxicity in coal miners. Urinary PAH metabolites, neurotransmitters, and oxidative stress biomarkers of 652 coal miners were examined. Subjects were divided into high and low-exposure groups based on the median of total urinary PAH metabolites. Differentially expressed miRNAs were screened from 5 samples in the low-exposure group (≤ 4.88 μmol/mol Cr) and 5 samples in the high-exposure group (> 4.88 μmol/mol Cr) using microarray technology, followed by bioinformatics analysis of the potential molecular functions of miRNA target genes. Reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) was used to validate differentially expressed miRNAs. Restricted cubic splines (RCS) were applied to assess the possible dose-response relationships. Compared to the low PAH exposure group, the high-exposure group had higher levels of 5-hydroxytryptamine (5-HT), epinephrine (E), and acetylcholine (ACh), and lower levels of acetylcholinesterase (AChE). 1-OHP had a dose-response relationship with malondialdehyde (MDA), dopamine (DA), 5-HT, and AChE (P for overall associations < 0.05). There were 19 differentially expressed microRNAs in microarray analysis, significantly enriched in the cell membrane, molecular binding to regulate transcription, and several signaling pathways such as PI3K-Akt. And in the validation stage, miR-885-5p, miR-20a-5p, and let-7i-3p showed differences in the low and high-exposure groups (P < 0.05). Changes in neurotransmitters and microRNA expression levels among the coal miners were associated with PAH exposure. Their biological functions are mainly related to the transcriptional regulation of nervous system diseases or signaling pathways of disorders. These findings provide new insights for future research of PAH neurotoxicity.

Current Review of Pneumoconiosis Among US Coal Miners

PURPOSE OF REVIEW

This review summarizes recent research on pneumoconiosis in coal workers following the identification of the resurgence of this disease among US coal miners in the early 2000s. We describe the impact of this research and how this has led to increased public attention, benefitting affected miners.

RECENT FINDINGS

The latest research shows that the prevalence of pneumoconiosis, including progressive massive fibrosis, continues to increase, especially in central Appalachia. Contributing factors may include mining of thin coal seams or cutting rock to access coal, which may expose miners to coal mine dust with a higher content of silica and silicates than in the past. The impact of recently implemented changes, such as the reduced occupational exposure limit for respirable coal mine dust and the introduction of continuous personal dust monitors, will likely take years to appropriately evaluate.

[Association between dust exposure and the risk of hypertension of male coal miners in Henan Province]

Objective: To explore the association between dust exposure and the incidence of hypertension in male coal miners. Methods: Using the method of retrospective cohort study,a hypertension cohort of colliery in Henan Province was established in January 2006. From 2006 to 2017,all the male coal miners in a colliery who were exposed to dust were selected into the exposure group including tunneling, mining,auxiliary and combining workers, and workers from administrative logistics departments who were not exposed to dust were selected into the control group. The eligible participants should satisfy following conditions: working more than one year, with clear and complete record of occupation change, and with complete archives and reliable diagnosis of occupational health surveillance. The exclusion criteria of participants were with hypertension at the baseline of study or with heart,liver,kidney diseases and malignant tumors. A total of 12 647 participants were enrolled in this study (11 663 in the exposure group and 984 in the control group). The follow-up period was from January 2006 to December 2017,with a total follow-up of 89 259.75 person-years. Questionnaires and physical measurements were used to collect general demographic characteristics, occupational exposure history and occupational health surveillance data of all participants. The Cox proportional hazards regression model was used to estimate the association between the dust exposure and the incidence of hypertension. Results: During the follow-up period, 2 549 new-onset hypertension patients were identified with an incidence density of hypertension about 2 855.71 per 100 000 person-years. The incidence density of hypertension was 2 967.58 per 100 000 person-years in the exposure group, and 1 643.85 per 100 000 person-years in the control group. The results of multivariate Cox proportional hazards regression model showed that after the adjustment of marriage, age, smoking, alcohol drinking and body mass index,the risk of hypertension was higher in the exposure group compared with the control group (HR=1.692, 95%CI: 1.410-2.032). Further analysis showed that compared with workers from administrative logistics departments,the risk of hypertension in tunneling,mining and auxiliary working was 1.629(1.345-1.973),1.677(1.374-2.046) and 1.782(1.475-2.151),respectively. Conclusion: Dust exposure may increase the risk of hypertension in male coal miners.

Quality of life and influencing factors of coal miners in Xuzhou, China

Background

Coal industry is one of the national pillar industries in China. A large number of coal miners are exposed to various occupational hazards, which might cause occupational disease. The aim of the study was to assess the quality of life (QOL) of coal miners in Xuzhou, China and explore influencing factors to QOL of coal miners.

Methods

Six hundred and twelve underground miners and 354 ground workers in one of coal mines of Xuzhou were enrolled in our study. The 36-item Short-Form Health Survey (SF-36) questionnaires were applied to evaluate the QOL of coal miners. Multivariate stepwise regression analysis was used to assess the potential impact factors on QOL.

Results

The score of role limitations due to physical health problems (RP) dimension in underground miners was significantly lower than that of ground workers (P=0.005). Multivariate stepwise regression analysis showed that longer job tenure for dust exposure significantly lower coal miners' RP score. Comparing with normal populations, our subjects scored lower in both the physical health components (PHC) and the mental health components (MHC), and many factors accounted for it including job tenure for dust exposure, chronic disease, medical insurance, etc.

Conclusions

QOL of coal miners has been affected. Some measures might be taken by enterprise and coal miners themselves to protect the health of coal miners and improve their quality of life.

Prevalence of dyslipidaemia and risk factors in Chinese coal miners: a cross-sectional survey study

Background

Although coal miners are susceptible to dyslipidaemia owing to their highly risky and stressful working environment as well as unhealthy lifestyle, very few studies have focused on this issue thus far. Therefore, this study investigated the current epidemiological characteristics of dyslipidaemia among Chinese coal miners.

Methods

Demographic, anthropometric, and biochemical data were gathered from 4341 coal miners in China. Dyslipidaemia was diagnosed based on the serum lipid levels. Univariate and multivariate logistic regression analyses were used to assess the related risk factors for dyslipidaemia.

Results

The average concentrations of total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were 5.01 ± 0.93 mmol/L, 1.90 ± 1.72 mmol/L, 1.21 ± 0.35 mmol/L, and 3.15 ± 0.80 mmol/L, respectively. Additionally, 38.08% of participants had a high TC level, 25.84% had a low HDL-C level, 35.08% had a high LDL-C level, and 40.46% had a high TG level. The overall prevalence of dyslipidaemia was 68.28% (95% CI: 66.90–69.66%). Factors associated with dyslipidaemia were age, sex, marital status, monthly family income, type of work, length of service, smoking status, smoking index, drinking status, alcohol consumption per day, elevated fasting glucose, hypertension, obesity and abdominal obesity.

Conclusions

Our study’s results indicated a very high prevalence of dyslipidaemia among Chinese coal miners and identified various risk factors for dyslipidaemia.

[Correlative factors on prevalence rate of dislipidemia among 1 337 coal miners in Shanxi province]

Objective: To understand the prevalence rate and correlative factors of dislipidemia among Shanxi coal miners and to provide evidence for the development of programs on dislipidemia prevention. Methods: We investigated 1 337 mine workers from a Coal Group in April 2016 and collected data related to their blood biochemistry. We then classified the types in accordance with the diagnostic criteria of " Guidelines for prevention and treatment of dyslipidemia in Chinese adults (2007)" , using χ(2) test and unconditional logistic regression model for analysis. Results: The overall prevalence rate of Dislipidemia was 59.1% (790/1 337), with males as 60.4% (708/1 173) and females as 50.0%(82/164) while males appeared higher (χ(2)=6.386, P<0.05). Among the 20-34, 35-49, 50 and above year-old groups, the rates were 68.8%, 58.7%, 49.5%, respectively. Results from the χ(2) test showed that gender, age and body mass index were the influencing factors on dislipidemia (χ(2)=7.117, P<0.01; χ(2)=37.135, P<0.01; χ(2)=7.009, P<0.05), while logistic regression analysis showed that sex, age, body mass index level, systolic blood pressure were significantly associated with dislipidemia (P<0.05). Male miners appeared 1.501 times (OR=1.501, 95%CI: 1.895-2.516) higher than female miners in suffering from the risk of dyslipidemia. In different age groups, risks of dyslipidemia in the 35-49, 20-34 year-old groups were 1.672 (OR=1.672, 95%CI: 1.501-2.392) and 2.369 times (OR= 2.369, 95% CI: 1.275-3.469) higher than the 50 year-old. Group that with high BMI, the risk of dyslipidemia was 1.443 times (OR=1.443, 95%CI: 1.139-1.828) higher than the normal BMI group. Group with abnormal systolic pressure was 1.829 times (OR=1.829, 95%CI: 1.152-2.906) higher than normal systolic pressure group. However, diastolic blood pressure, blood sugar, uric acid, and electrocardiogram findings did not seem to show statistically significant meanings on dislipidemia. Conclusion: Among the coal mine workers, those who were males, aged from 20 to 34, having high blood pressure (systolic blood pressure abnormalities) or with high BMI (≥24.0 kg/m(2)) need to be taken special attention on care and prevention of dislipidemia.

An approach to adjust standardized mortality ratios for competing cause of death in cohort studies

Purpose

The calculation of standardized mortality ratios (SMRs) is a standard tool for the estimation of health risks in occupational epidemiology. An increasing number of studies deal with the analysis of the mortality in employees suffering from an occupational disease like silicosis or coal-worker pneumoconiosis (CWP). Their focus lies not on the mortality risk due to the occupational disease itself, but on other diseases such as lung cancer or heart diseases. Using population-based reference rates in these studies can cause misleading results because mortality rates of the general population do not reflect the elevated mortality due to the occupational disease investigated. Hence, the purpose of the present paper is to develop an approach to adjust the risk estimates for other causes of death with respect to the effect of an occupational disease as a competing cause of death in occupational mortality cohort studies.

Methods

To overcome the problems associated with SMRs, the paper makes use of proportional mortality ratios (PMR), which are a further approach for the estimation of health risks in occupational epidemiology. The cause-specific SMR can be rewritten as a product of PMR times the overall SMR. The PMR can be adjusted by ignoring the competing cause of death. Hence, an adjusted cause-specific SMR can be derived by multiplying this adjusted PMR with the overall SMR. This approach is applied to studies concerning lung cancer risk in coal miners suffering from CWP.

Results and conclusions

The usual approach for calculating SMRs leads to an underestimation of the real lung cancer risk in subgroups of miners suffering from CWP. The same effect can be observed in workers exposed to respirable silica already suffering from silicosis. The presented approach results in more realistic risk estimation in mortality cohort studies of employees suffering from an occupational disease. It is easily calculable on the basis of usually published values of observed cases and the corresponding cause-specific SMR.

Genetic damage in coal miners evaluated by buccal micronucleus cytome assay

During coal mining activities, large quantities of coal dust, ashes, polycyclic aromatic hydrocarbons and metals are released into the environment. This complex mixture presents one of the most important occupational hazards for health of workers. The aim of the present study was to evaluate the genetic damage together with the presence of inorganic elements, in an exposed workers population to coal mining residues of Guajira-Colombia. Thus, 100 exposed workers and 100 non-exposed control individuals were included in this study. To determine genetic damage we assessed the micronucleus (MN) frequencies and nuclear buds in buccal mucosa samples (BMCyt) assay, which were significantly higher in the exposed group than non-exposed control group. In addition, karyorrhectic and karyolytic cells were also significantly higher in the exposed group (cell death). No significant difference was observed between the exposed groups engaged in different mining activities. No correlation between age, alcohol consumption, time of service and MN assay data were found in this study. However, the content of inorganic elements in blood samples analyzed by a Particle-induced X-ray emission technique (PIXE) showed higher values of silicon (Si) and aluminum (Al) in the exposed group. In this study we discuss the possibility of DNA damage observed in the mine workers cells be a consequence of oxidative damage.

pylori infection, some risk factors and gastroduodenal diseases in coal miners

AIM: To search for the risk factors that influences the prevalence rate of gastroduodenal diseases in coal miners, and to seek protection for the health of coal miners.

METHODS: A total of 340 coal miners from three coalmines were chosen by the method of stratified random cluster sampling. Face to face interview was conducted to fill the unified questionaire. Gastroendoscopy were performed in 306 subjects to detect the situation of gastroduodenal diseases according to Sydney system of diagnosis. At the same time, mucosal biopsies were taken according to the regulated location for H. pylori culture and pathological examination. Blood samples were obtained to detect the anti-H. pylori U-IgG by enzyme-linked immunosorbent assay (ELISA).

RESULTS: The prevalence rate of gastroduodenal diseases in coal miners was 77.8% (68.5% in ground coal miners, 80.7% in underground miners). The prevalence rate of gastroduodenal diseases was 85.0% in coal miners with H. pylori infection, and 58.6% in those without H. pylori infection; it was 79.5% in coal miners who drank alcohol and 66.7% in those who didn't drink.

CONCLUSION: Alcohol-drinking, career, and H. pylori infection were risk factors of gastroduodenal diseases, and dust exposure was also a risk factor in underground coal miners.