Radon activity concentration RnCA and workers lung cancer risks in SENA coal mines, Colombia

The risk of lung cancer or pneumoconiosis mortality, increases with radioactive radon gas exposures. This article report health risk for underground workers exposed to radioactive gas and radon daughters carried by airborne dust at the coal mining in the Central Mountainous Region of Colombia. A set of 33 measurement points located in that mine galleries were selected to monitor radon gas concentration activity, by passive LR-115 detectors, during two months. Resulting values provided radon concentrations, absorbed dose, environmental equivalent dose and the effective dose; miners increased risk of contracting lung cancer is included. It is concluded that the mine ventilation system satisfies the conditions required by the current radiological protection of the miners. Our study point out that Colombia can effectively address the potential risks associated with radon exposure and ensure a safer living environment for its citizens.

A nested case-control study of the effects of dust exposure, smoking on COPD in coal workers

BACKGROUND

Chronic obstructive pulmonary disease (COPD) represents a prevalent ailment, progressively surging within the ranks of coal mine laborers. The current study endeavors to elucidate the effects of dust exposure and smoking on COPD incidence amongst coal mine workers, while concurrently devising preventive strategies for this affliction.

METHOD

A nested case-control study was conducted encompassing 1,416 participants aged ≥ 18 years, spanning the duration from (2017-2018) until 2020. A meticulous matching process yielded a cohort of 708 COPD patients, each paired with a control subject, forming a harmonious 1:1 ratio. Multiple logistic regression analysis was employed to scrutinize the associations between smoking, dust exposure with COPD among coal workers.

RESULTS

The COPD prevalence within the cohort of coal workers under investigation amounted to 22.66%, with an accompanying incidence density of 0.09/person-year. Following meticulous adjustment for confounding variables, it was discerned that cumulative dust exposure within the range of 47.19 ~ (OR: 1.90, 95% CI: 1.05, 3.44), 101.27 ~ (OR: 1.99, 95% CI: 1.17, 3.39), as well as smoking indices of 72 ~ (OR: 1.85, 95% CI: 1.19, 2.88), 145 ~ (OR: 1.74, 95% CI: 1.17, 2.61), 310 ~ (OR: 1.85, 95% CI: 1.23, 2.77) engender an escalated vulnerability to COPD among coal workers. Furthermore, interaction analysis discerned an absence of both multiplicative and additive interactions between dust exposure, smoking, and COPD occurrence amidst coal workers.

CONCLUSION

Dust exposure and smoking were unequivocally identified as precipitating risk factors for COPD incidence within the population of coal workers, albeit devoid of any discernible interaction between these two causal agents.

Exposure to smoky coal combustion emissions and leukocyte Alu retroelement copy number

Household air pollution (HAP) from indoor combustion of solid fuel is a global health burden that has been linked to multiple diseases including lung cancer. In Xuanwei, China, lung cancer rate for non-smoking women is among the highest in the world and largely attributed to high levels of polycyclic aromatic hydrocarbons (PAHs) that are produced from combustion of smoky (bituminous) coal. Alu retroelements, repetitive mobile DNA sequences that can somatically multiply and promote genomic instability have been associated with risk of lung cancer and diesel engine exhaust exposure. We conducted analyses for 160 non-smoking women in an exposure assessment study in Xuanwei, China with a repeat sample from 49 subjects. Quantitative PCR was used to measure Alu repeat copy number relative to albumin gene copy number (Alu/ALB ratio). Associations between clusters derived from predicted levels of 43 HAP constituents, 5-methylchrysene (5-MC), a PAH previously associated with lung cancer in Xuanwei and was selected a priori for analysis, and Alu repeats were analyzed using generalized estimating equations. A cluster of 31 PAHs reflecting current exposure was associated with increased Alu copy number (β:0.03 per standard deviation change; 95% confidence interval (CI):0.01,0.04; P-value = 2E-04). One compound within this cluster, 5-MC, was also associated with increased Alu copy number (P-value = 0.02). Our findings suggest that exposure to PAHs due to indoor smoky coal combustion may contribute to genomic instability. Additionally, our study provides further support for 5-MC as a prominent carcinogenic component of smoky coal emissions. Further studies are needed to replicate our findings.

Historical shift in pathological type of progressive massive fibrosis among coal miners in the USA

BACKGROUND

Pneumoconiosis among coal miners in the USA has been resurgent over the past two decades, despite modern dust controls and regulatory standards. Previously published studies have suggested that respirable crystalline silica (RCS) is a contributor to this disease resurgence. However, evidence has been primarily indirect, in the form of radiographic features.

METHODS

We obtained lung tissue specimens and data from the National Coal Workers' Autopsy Study. We evaluated specimens for the presence of progressive massive fibrosis (PMF) and used histopathological classifications to type these specimens into coal-type, mixed-type and silica-type PMF. Rates of each were compared by birth cohort. Logistic regression was used to assess demographic and mining characteristics associated with silica-type PMF.

RESULTS

Of 322 cases found to have PMF, study pathologists characterised 138 (43%) as coal-type, 129 (40%) as mixed-type and 55 (17%) as silica-type PMF. Among earlier birth cohorts, coal-type and mixed-type PMF were more common than silica-type PMF, but their rates declined in later birth cohorts. In contrast, the rate of silica-type PMF did not decline in cases from more recent birth cohorts. More recent year of birth was significantly associated with silica-type PMF.

CONCLUSIONS

Our findings demonstrate a shift in PMF types among US coal miners, from a predominance of coal- and mixed-type PMF to a more commonly encountered silica-type PMF. These results are further evidence of the prominent role of RCS in the pathogenesis of pneumoconiosis among contemporary US coal miners.

Household air pollution and epigenetic aging in Xuanwei, China

BACKGROUND

Household air pollution (HAP) from indoor combustion of solid fuel is a global health burden linked to lung cancer. In Xuanwei, China, lung cancer rate for nonsmoking women is among the highest in the world and largely attributed to high levels of polycyclic aromatic hydrocarbons (PAHs) that are produced from combustion of smoky (bituminous) coal used for cooking and heating. Epigenetic age acceleration (EAA), a DNA methylation-based biomarker of aging, has been shown to be highly correlated with biological processes underlying the susceptibility of age-related diseases. We aim to assess the association between HAP exposure and EAA.

METHODS

We analyzed data from 106 never-smoking women from Xuanwei, China. Information on fuel type was collected using a questionnaire, and validated exposure models were used to predict levels of 43 HAP constituents. Exposure clusters were identified using hierarchical clustering. EAA was derived for five epigenetic clocks defined as the residuals resulting from regressing each clock on chronological age. We used generalized estimating equations to test associations between exposure clusters derived from predicted levels of HAP exposure, ambient 5-methylchrysene (5-MC), a PAH previously found to be associated with risk of lung cancer, and EAA, while accounting for repeated-measurements and confounders.

RESULTS

We observed an increase in GrimAge EAA for clusters with 31 and 33 PAHs reflecting current (β = 0.77 y per standard deviation (SD) increase, 95 % CI:0.36,1.19) and childhood (β = 0.92 y per SD, 95 % CI:0.40,1.45) exposure, respectively. 5-MC (ng/m3-year) was found to be associated with GrimAge EAA for current (β = 0.15 y, 95 % CI:0.05,0.25) and childhood (β = 0.30 y, 95 % CI:0.13,0.47) exposure.

CONCLUSIONS

Our findings suggest that exposure to PAHs from indoor smoky coal combustion, particularly 5-MC, is associated with GrimAge EAA, a biomarker of mortality.

First Case Report Of Anca-Associated Vasculitis And Anthracosis Coexistence

Anthracosis is a type of mild pneumoconiosis secondary to harmless carbon dust deposits. Although anthracosis was previously associated with inhaled coal particles, such as coal workers' pneumoconiosis, this hypothesis was later abandoned; pathology has been associated with inhaled dust particles. Our paper is the first case report of ANCA-associated vasculitis and anthracosis coexistence. In addition, it aims to highlight that histopathologically proven anthracotic granulomatous nodules can show high FDG uptake in PET/CT contrary to expectation. We present a case of a 73-year-old male with p-ANCA-associated vasculitis and anthracotic lung nodules accompanied by radiological and clinical findings. The patient got diagnosis with p-ANCA-associated vasculitis with serological and rheumatological tests. Atypically, the clinical findings of the patient were weak (No dyspnoea, cough or additional pulmonary complaints). Nodules were present on X-ray graphics and nodules' contours were irregular on CT. On PET/CT, SUV values of the nodules were high [12 kBq/mL]. Histopathological specimens showed multiple lung granulomas including anthracosis particles. Until performing the biopsy, we could not exclude the possibility of malignancy. Conclusion: When lung involvement of vasculitis is superimposed by anthracosis, it can create granulomas with high SUV values. The relationship between anthracosis and parenchymal lung diseases is a current topic and many recently published papers are present on this subject. To the best of our knowledge, our paper is the first paper showing the relationship between parenchymal involvement of vasculitis and anthracosis in the literature. Environmental pollution and dust particles are the known reasons for anthracosis particles in the nodules. It is open to future research on whether air pollution triggers new atypical cases or not.

A global review of the state of the evidence of household air pollution's contribution to ambient fine particulate matter and their related health impacts

Direct exposure to household fine particulate air pollution (HAP) associated with inefficient combustion of fuels (wood, charcoal, coal, crop residues, kerosene, etc.) for cooking, space-heating, and lighting is estimated to result in 2.3 (1.6-3.1) million premature yearly deaths globally. HAP emitted indoors escapes outdoors and is a leading source of outdoor ambient fine particulate air pollution (AAP) in low- and middle-income countries, often being a larger contributor than well-recognized sources including road transport, industry, coal-fired power plants, brick kilns, and construction dust. We review published scientific studies that model the contribution of HAP to AAP at global and major sub-regional scales. We describe strengths and limitations of the current state of knowledge on HAP's contribution to AAP and the related impact on public health and provide recommendations to improve these estimates. We find that HAP is a dominant source of ambient fine particulate matter (PM2.5) globally - regardless of variations in model types, configurations, and emission inventories used - that contributes approximately 20 % of total global PM2.5 exposure. There are large regional variations: in South Asia, HAP contributes ∼ 30 % of ambient PM2.5, while in high-income North America the fraction is ∼ 7 %. The median estimate indicates that the household contribution to ambient air pollution results in a substantial premature mortality burden globally of about 0.77(0.54-1) million excess deaths, in addition to the 2.3 (1.6-3.1) million deaths from direct HAP exposure. Coordinated global action is required to avert this burden.

Methylated polycyclic aromatic hydrocarbons from household coal use across the life course and risk of lung cancer in a large cohort of 42,420 subjects in Xuanwei, China

BACKGROUND

We previously showed that exposure to 5-methylchrysene (5MC) and other methylated polycyclic aromatic hydrocarbons (PAHs) best explains lung cancer risks in a case-control study among non-smoking women using smoky coal in China. Time-related factors (e.g., age at exposure) and non-linear relations were not explored.

OBJECTIVE

We investigated the relation between coal-derived air pollutants and lung cancer mortality using data from a large retrospective cohort.

METHODS

Participants were smoky (bituminous) or smokeless (anthracite) coal users from a cohort of 42,420 subjects from four communes in XuanWei. Follow-up was from 1976 to 2011, during which 4,827 deaths from lung-cancer occurred. Exposures were predicted for 43 different pollutants. Exposure clusters were identified using hierarchical clustering. Cox regression was used to estimate exposure-response relations for 5MC, while effect modification by age at exposure was investigated for cluster prototypes. A Bayesian penalized multi-pollutant model was fitted on a nested case-control sample, with more restricted models fitted to investigate non-linear exposure-response relations.

RESULTS

We confirmed the strong exposure-response relation for 5MC (Hazard Ratio [95% Confidence Interval] = 2.5 [2.4, 2.6] per standard-deviation (SD)). We identified four pollutant clusters, with all but two PAHs in a single cluster. Exposure to PAHs in the large cluster was associated with a higher lung cancer mortality rate (HR [95%CI] = 2.4 [2.2, 2.6] per SD), while exposure accrued before 18 years of age appeared more important than adulthood exposures. Results from the multi-pollutant model identified anthanthrene (ANT) and benzo(a)chrysene (BaC) as risk factors. 5MC remained strongly associated with lung cancer in models that included ANT and BaC and also benzo(a)pyrene (BaP).

CONCLUSION

We confirmed the link between PAH exposures and lung cancer in smoky coal users and found exposures before age 18 to be especially important. We found some evidence for the carcinogen 5MC and non-carcinogens ANT and BaC.

Increased odds of mortality from non-malignant respiratory disease and lung cancer are highest among US coal miners born after 1939

OBJECTIVES

Coal miners suffer increased mortality from non-malignant respiratory diseases (NMRD), including pneumoconioses and chronic obstructive pulmonary disease, compared with the US population. We characterised mortality trends from NMRD, lung cancer and ischaemic heart disease (IHD) using data from the Federal Black Lung Program, National Coal Workers' Health Surveillance Program and the National Death Index.

METHODS

We compared mortality ORs (MORs) for NMRD, lung cancer and IHD in former US coal miners to US white males. MORs were computed for the study period 1979-2017 by birth cohort (<1920, 1920-1929, 1930-1939, ≥1940), with a subanalysis restricted to Central Appalachia.

RESULTS

The study population totalled 235 550 deceased miners, aged >45 years. Odds of death from NMRD and lung cancer across all miner birth cohorts averaged twice those of US males. In Central Appalachia, MORs significantly increased across birth cohorts. There was an eightfold increase in odds of death from NMRD among miners born after 1940 (MORBC≥1940 8.25; 95% CI 7.67 to 8.87). Miners with progressive massive fibrosis (PMF) were younger at death than those without PMF (74 vs 78 years; p<0.0001). We observed a pattern of reduced MORs from IHD in coal miners compared with national and regional counterparts.

CONCLUSION

US coal miners have excess mortality from NMRD and lung cancer compared with total US and Appalachian populations. Mortality is highest in the most recent birth cohorts, perhaps reflecting increased rates of severe pneumoconiosis.

Indoor air pollution from coal combustion and tobacco smoke during the periconceptional period and risk for neural tube defects in offspring in five rural counties of Shanxi Province, China, 2010-2016

Indoor air pollution may increase the risk for neural tube defects (NTDs) in Chinese rural populations. However, this association remains a subject of debate. We conducted a population-based case-control study of 222 NTD and 517 control mothers recruited between 2010 and 2016 in five rural areas in northern China. An indoor air pollution exposure evaluation index (IAPEEI) was used to evaluate mothers' exposure to tobacco-sourced and coal-sourced indoor air pollution. Essential characteristics were collected using structured questionnaires within 10 days of delivery. We found that exposure to indoor air pollution (IAPEEI ≥ 1) can lead to 3.41 times the risk of conceiving NTD fetuses compared with the no-exposure group (IAPEEI = 0) (adjusted odds ratio and 95 % confidence interval: 3.41 [2.34-5.02]). The risk increased with increasing IAPEEI score, indicating a clear dose-response trend (P < 0.001). Using a coal stove for heating (especially in the bedroom) and passive smoking are significantly associated with an increased likelihood of NTD occurrence. Exposure to indoor air pollution is a daily reality for rural women in China, and its impact on reproductive health deserves extensive attention.

Overall and cause-specific mortality rates among men and women with high exposure to indoor air pollution from the use of smoky and smokeless coal: a cohort study in Xuanwei, China

OBJECTIVES

Never-smoking women in Xuanwei (XW), China, have some of the highest lung cancer rates in the country. This has been attributed to the combustion of smoky coal used for indoor cooking and heating. The aim of this study was to evaluate the spectrum of cause-specific mortality in this unique population, including among those who use smokeless coal, considered 'cleaner' coal in XW, as this has not been well-characterised.

DESIGN

Cohort study.

SETTING

XW, a rural region of China where residents routinely burn coal for indoor cooking and heating.

PARTICIPANTS

Age-adjusted, cause-specific mortality rates between 1976 and 2011 were calculated and compared among lifetime smoky and smokeless coal users in a cohort of 42 420 men and women from XW. Mortality rates for XW women were compared with those for a cohort of predominately never-smoking women in Shanghai.

RESULTS

Mortality in smoky coal users was driven by cancer (41%), with lung cancer accounting for 88% of cancer deaths. In contrast, cardiovascular disease (CVD) accounted for 32% of deaths among smokeless coal users, with 7% of deaths from cancer. Total cancer mortality was four times higher among smoky coal users relative to smokeless coal users, particularly for lung cancer (standardised rate ratio (SRR)=17.6). Smokeless coal users had higher mortality rates of CVD (SRR=2.9) and pneumonia (SRR=2.5) compared with smoky coal users. These patterns were similar in men and women, even though XW women rarely smoked cigarettes. Women in XW, regardless of coal type used, had over a threefold higher rate of overall mortality, and most cause-specific outcomes were elevated compared with women in Shanghai.

CONCLUSIONS

Cause-specific mortality burden differs in XW based on the lifetime use of different coal types. These observations provide evidence that eliminating all coal use for indoor cooking and heating is an important next step in improving public health particularly in developing countries.

Glycogen metabolism reprogramming promotes inflammation in coal dust-exposed lung

Long-term coal dust exposure triggers complex inflammatory processes in the coal workers' pneumoconiosis (CWP) lungs. The progress of the inflammation is reported to be affected by disordered cell metabolism. However, the changes in the metabolic reprogramming associated with the pulmonary inflammation induced by the coal dust particles are unknown. Herein, we show that coal dust exposure causes glycogen accumulation and the reprogramming of glucose metabolism in the CWP lung. The glycogen accumulation caused by coal dust is mainly due to macrophages, which reprogram glycogen metabolism and trigger an inflammatory response. In addition, 2-deoxy-D-glucose (2-DG) reduced glycogen content in macrophages, which was accompanied by mitigated inflammation and restrained NF-κB activation. Accordingly, we have pinpointed a novel and crucial metabolic pathway that is an essential regulator of the inflammatory phenotype of coal dust-exposed macrophages. These results shed light on new ways to regulate CWP inflammation.

Coal Miners and Lung Cancer: Can Mortality Studies Offer a Perspective on Rat Inhalation Studies of Poorly Soluble Low Toxicity Particles?

Inhalation studies involving laboratory rats exposed to poorly soluble particles (PSLTs), such as carbon black and titanium dioxide, among others, have led to the development of lung cancer in conditions characterized as lung overload. Lung overload has been described as a physiological state in which pulmonary clearance is impaired, particles are not effectively removed from the lungs and chronic inflammation develops, ultimately leading to tumor growth. Since lung tumors have not occurred under similar states of lung overload in other laboratory animal species, such as mice, hamsters and guinea pigs, the relevance of the rat as a model for human risk assessment has presented regulatory challenges. It has been suggested that coal workers' pneumoconiosis may reflect a human example of apparent "lung overload" of poorly soluble particles. In turn, studies of risk of lung cancer in coal miners may offer a valuable perspective for understanding the significance of rat inhalation studies of PSLTs on humans. This report addresses whether coal can be considered a PSLT based on its composition in contrast to carbon black and titanium dioxide. We also review cohort mortality studies and case-control studies of coal workers. We conclude that coal differs substantially from carbon black and titanium dioxide in its structure and composition. Carbon black, a manufactured product, is virtually pure carbon (upwards of 98%); TiO2 is also a manufactured product. Coal contains carcinogens such as crystalline silica, beryllium, cadmium and iron, among others; in addition, coal mining activities tend to occur in the presence of operating machinery in which diesel exhaust particles, a Type I Human carcinogen, may be present in the occupational environment. As a result of its composition and the environment in which coal mining occurs, it is scientifically inappropriate to consider coal a PSLT. Despite coal not being similar to carbon black or TiO2, through the use of a weight of evidence approach-considered the preferred method when evaluating disparate studies to assess risk- studies of coal-mine workers do not indicate a consistent increase in lung cancer risk. Slight elevations in SMR cannot lead to a reliable conclusion about an increased risk due to limitations in exposure assessment and control of inherent biases in case-control studies, most notably confounding and recall bias. In conclusion, the weight of the scientific literature suggests that coal mine dust is not a PSLT, and it does not increase lung cancer risk.

[Progress in the epidemiological studies on coal mine dust exposure with workers' health damage]

Coal is one of the major fuels, which brings huge energy and economic benefits to global industry and daily life. large amounts of coal dust produced in the process of coal mining and transportation, which seriously threatens the health of related workers. Productive coal dust exposure not only directly leads to respiratory diseases, but also may cause health damage to various systems throughout the body. Numerous studies have shown that coal dust exposure is closely associated with decreased lung function, coal worker's pneumoconiosis, chronic obstructive pulmonary disease, lung cancer, and cardiovascular diseases, and the severity of diseases is affected by coal rank, coal dust concentration, cumulative dust exposure, coal dust composition, and individual lifestyle, etc. The article comprehensively summarized the progress of the epidemiological studies on the health hazards of coal miners from coal dust exposure, in order to provide clues for further researches on health damage and protect the health of the occupational population.

Solid fuel use, socioeconomic indicators and risk of cardiovascular diseases and all-cause mortality: a prospective cohort study in a rural area of Sichuan, China

BACKGROUND

Estimates indicate that household air pollution caused by solid fuel burning accounted for about 1.03 million premature mortalities in China in 2016. In the country's rural areas, more than half the population still relies on biomass fuels and coals for cooking and heating. Understanding the health impact of indoor air pollution and socioeconomic indicators is essential for the country to improve its developmental targets. We aimed to describe demographic and socioeconomic characteristics associated with solid fuel users in a rural area in China. We also estimated the risk of cardiovascular disease and all-cause mortality in association with solid fuel use and described the relationship between solid fuel use, socioeconomic status and mortality. We also measured the risk of long-term use, and the effect of ameliorative action, on mortality caused by cardiovascular disease and other causes.

METHODS

We used the China Kadoorie Biobank (CKB) site in Pengzhou, Sichuan, China. We followed a cohort of 55 687 people over 2004-13. We calculated the mean and standard deviation among subgroups classified by fuel use types: gas, coal, wood and electricity (central heating additionally for heating). We tested the mediation effect using the stepwise method and Sobel test. We used Cox proportional models to estimate the risk of incidences of cardiovascular disease and mortality with survival days as the time scale, adjusted for age, gender, socioeconomic status, physical measurements, lifestyle, stove ventilation and fuel type used for other purposes. The survival days were defined as the follow-up days from the baseline survey till the date of death or 31 December 2013 if right-censored. We also calculated the absolute mortality rate difference (ARD) between the exposure group and the reference group.

RESULTS

The study population had an average age of 51.0, and 61.9% of the individuals were female; 64.8% participants (n = 35 543) cooked regularly and 25.4% participants (n = 13 921) needed winter heating. With clean fuel users as the reference group, participant households that used solid fuel for cooking or heating both had a higher risk of all-cause mortality: hazard ratio (HR) for: cooking, 1.11 [95% confidence interval (CI) 1.02, 1.26]; heating, 1.34 (95% CI 1.16, 1.54). Solid fuel used for winter heating was associated with a higher risk of mortality caused by cerebrovascular disease: HR 1.64 (95% CI 1.12, 2.40); stroke: HR 1.70 (95% CI 1.13, 2.56); and cardiovascular disease: HR 1.49 (95% CI 1.10, 2.02). Low income and poor education level had a significant correlation with solid fuel used for cooking: odds ratio (OR) for income: 2.27 (95% CI 2.14, 2.41); education: 2.34 (95% CI 2.18, 2.53); and for heating: income: 2.69 (95% CI 2.46, 2.97); education: 2.05 (95% CI 1.88, 2.26), which may be potential mediators bridging the effects of socioeconomic status factors on cardiovascular disease and all-cause mortality. Solid fuel used for cooking and heating accounted for 42.4% and 81.1% of the effect of poor education and 55.2% and 76.0% of the effect of low income on all-cause mortality, respectively. The risk of all-cause mortality could be ameliorated by stopping regularly cooking and heating using solid fuel or switching from solid fuel to clean fuels: HR for cooking: 0.90 (95% CI 0.84, 0.96); heating: 0.76 (95% CI 0.64, 0.92).

CONCLUSIONS

Our study reinforces the evidence of an association between solid fuel use and risk of cardiovascular disease and all-cause mortality. We also assessed the effect of socioeconomic status as the potential mediator on mortality. As solid fuel use was a major contributor in the effect of socioeconomic status on cardiovascular disease and all-cause mortality, policies to improve access to clean fuels could reduce morbidity and mortality related to poor education and low income.

The Influence of the Material Structure on the Mechanical Properties of Geopolymer Composites Reinforced with Short Fibers Obtained with Additive Technologies

Additive manufacturing technologies have a lot of potential advantages for construction application, including increasing geometrical construction flexibility, reducing labor costs, and improving efficiency and safety, and they are in line with the sustainable development policy. However, the full exploitation of additive manufacturing technology for ceramic materials is currently limited. A promising solution in these ranges seems to be geopolymers reinforced by short fibers, but their application requires a better understanding of the behavior of this group of materials. The main objective of the article is to investigate the influence of the microstructure of the material on the mechanical properties of the two types of geopolymer composites (flax and carbon-reinforced) and to compare two methods of production of geopolymer composites (casting and 3D printing). As raw material for the matrix, fly ash from the Skawina coal power plant (located at: Skawina, Lesser Poland, Poland) was used. The provided research includes mechanical properties, microstructure investigations with the use of scanning electron microscope (SEM), confocal microscopy, and atomic force microscope (AFM), chemical and mineralogical (XRD-X-ray diffraction, and XRF-X-ray fluorescence), analysis of bonding in the materials (FT-IR), and nuclear magnetic resonance spectroscopy analysis (NMR). The best mechanical properties were reached for the sample made by simulating 3D printing process for the composite reinforced by flax fibers (48.7 MPa for the compressive strength and 9.4 MPa for flexural strength). The FT-IR, XRF and XRD results show similar composition of all investigated materials. NMR confirms the presence of SiO₄ and AlO₄ tetrahedrons in a three-dimensional structure that is crucial for geopolymer structure. The microscopy observations show a better coherence of the geopolymer made in additive technology to the reinforcement and equal fiber distribution for all investigated materials. The results show the samples made by the additive technology had comparable, or better, properties with those made by a traditional casting method.

The impact of the Hazelwood coal mine fire smoke exposure on asthma

OBJECTIVE

In 2014, a fire at an open cut coal mine in South-eastern Australia burned for about 6 weeks. Residents of the adjacent town were exposed to high levels of fine particulate matter (PM2.5) during this period. Three and a half years after the event, this study aimed to investigate potential long-term impacts of short-term exposure to coal mine fire smoke on asthma.

METHODS

A cross-sectional analysis was undertaken in a group of exposed participants with asthma from Morwell (n = 165) and a group of unexposed participants with asthma from the control town of Sale (n = 64). Exposure was determined by modeled PM2.5 data for the mine fire period. Respiratory symptoms were assessed with a validated respiratory health questionnaire and symptom severity score. Asthma control was assessed with a validated questionnaire. Lung function testing included spirometry, bronchodilator response, and fraction of exhaled nitric oxide.

RESULTS

There was no evidence that exposed participants had more severe asthma symptoms, worse lung function, or more eosinophilic airway inflammation than unexposed participants. However, there was some evidence that Morwell participants had more uncontrolled than well-controlled asthma, compared to the participants from Sale (adjusted relative risk ratio 2.71 95% CI: 1.02, 7.21, p = .046).

CONCLUSION

Three and a half years after exposure, coal mine fire smoke did not appear to be associated with more severe asthma symptoms or worse lung function but might be associated with poorer asthma control.

A comparative analysis of the principal component analysis and entropy weight methods to establish the indexing measurement

BACKGROUND

As the world's largest coal producer, China was accounted for about 46% of global coal production. Among present coal mining risks, methane gas (called gas in this paper) explosion or ignition in an underground mine remains ever-present. Although many techniques have been used, gas accidents associated with the complex elements of underground gassy mines need more robust monitoring or warning systems to identify risks. This paper aimed to determine which single method between the PCA and Entropy methods better establishes a responsive weighted indexing measurement to improve coal mining safety.

METHODS

Qualitative and quantitative mixed research methodologies were adopted for this research, including analysis of two case studies, correlation analysis, and comparative analysis. The literature reviewed the most-used multi-criteria decision making (MCDM) methods, including subjective methods and objective methods. The advantages and disadvantages of each MCDM method were briefly discussed. One more round literature review was conducted to search publications between 2017 and 2019 in CNKI. Followed two case studies, correlation analysis and comparative analysis were then conducted. Research ethics was approved by the Shanxi Coking Coal Group Research Committee.

RESULTS

The literature searched a total of 25,831publications and found that the PCA method was the predominant method adopted, and the Entropy method was the second most widely adopted method. Two weighting methods were compared using two case studies. For the comparative analysis of Case Study 1, the PCA method appeared to be more responsive than the Entropy. For Case Study 2, the Entropy method is more responsive than the PCA. As a result, both methods were adopted for different cases in the case study mine and finally deployed for user acceptance testing on 5 November 2020.

CONCLUSIONS

The findings and suggestions were provided as further scopes for further research. This research indicated that no single method could be adopted as the better option for establishing indexing measurement in all cases. The practical implication suggests that comparative analysis should always be conducted on each case and determine the appropriate weighting method to the relevant case. This research recommended that the PCA method was a dimension reduction technique that could be handy for identifying the critical variables or factors and effectively used in hazard, risk, and emergency assessment. The PCA method might also be well-applied for developing predicting and forecasting systems as it was sensitive to outliers. The Entropy method might be suitable for all the cases requiring the MCDM. There is also a need to conduct further research to probe the causal reasons why the PCA and Entropy methods were applied to each case and not the other way round. This research found that the Entropy method provides higher accuracy than the PCA method. This research also found that the Entropy method demonstrated to assess the weights of the higher dimension dataset was higher sensitivity than the lower dimensions. Finally, the comprehensive analysis indicates a need to explore a more responsive method for establishing a weighted indexing measurement for warning applications in hazard, risk, and emergency assessments.

Elevated urinary mutagenicity among those exposed to bituminous coal combustion emissions or diesel engine exhaust

Urinary mutagenicity reflects systemic exposure to complex mixtures of genotoxic/carcinogenic agents and is linked to tumor development. Coal combustion emissions (CCE) and diesel engine exhaust (DEE) are associated with cancers of the lung and other sites, but their influence on urinary mutagenicity is unclear. We investigated associations between exposure to CCE or DEE and urinary mutagenicity. In two separate cross-sectional studies of nonsmokers, organic extracts of urine were evaluated for mutagenicity levels using strain YG1041 in the Salmonella (Ames) mutagenicity assay. First, we compared levels among 10 female bituminous (smoky) coal users from Laibin, Xuanwei, China, and 10 female anthracite (smokeless) coal users. We estimated exposure-response relationships using indoor air concentrations of two carcinogens in CCE relevant to lung cancer, 5-methylchrysene (5MC), and benzo[a]pyrene (B[a]P). Second, we compared levels among 20 highly exposed male diesel factory workers and 15 unexposed male controls; we evaluated exposure-response relationships using elemental carbon (EC) as a DEE-surrogate. Age-adjusted linear regression was used to estimate associations. Laibin smoky coal users had significantly higher average urinary mutagenicity levels compared to smokeless coal users (28.4 ± 14.0 SD vs. 0.9 ± 2.8 SD rev/ml-eq, p = 2 × 10-5 ) and a significant exposure-response relationship with 5MC (p = 7 × 10-4 ). DEE-exposed workers had significantly higher urinary mutagenicity levels compared to unexposed controls (13.0 ± 10.1 SD vs. 5.6 ± 4.4 SD rev/ml-eq, p = .02) and a significant exposure-response relationship with EC (p-trend = 2 × 10-3 ). Exposure to CCE and DEE is associated with urinary mutagenicity, suggesting systemic exposure to mutagens, potentially contributing to cancer risk and development at various sites.

Household Air Pollution From Solid Cooking Fuel Combustion and Female Breast Cancer

Background: Women bear a large share of disease burden caused by household air pollution due to their great involvement in domestic activities. Pollutant emissions are believed to vary by exposure patterns such as cooking and space heating. Little is known about the independent effect of solid cooking fuel combustion on breast cancer risk. We aimed to examine the association of indoor coal and wood combustion for cooking with breast cancer risk. Methods: During June 2004-July 2008, participants aged 30-79 from 10 diverse regions across China were enrolled in the China Kadoorie Biobank. Primary cooking fuel use information in up to three residences was self-reported at baseline. Multivariable logistic regression models yielded adjusted odds ratios (ORs) and 95% confidence intervals (CIs). Results: A total of 290,396 female participants aged 30-79 were included in the main analysis. Compared with long-term clean fuel users, the fully adjusted ORs were 2.07 (95%CI: 1.37-3.13) for long-term coal users, 1.12 (95% CI: 0.72-1.76) for long-term wood users, and 0.98 (95% CI: 0.55-1.74) for those who used mixed solid fuels to cook. Those who had switched from solid to clean fuels did not have an excess risk of breast cancer (OR: 0.88, 95%CI 0.71-1.10). Conclusion: Long-term solid fuel combustion for cooking may increase the risk of breast cancer. The strength of association is stronger among coal users than wood users. Targeted interventions are needed to accelerate the access to clean and affordable energy.

Solid fuels use for cooking and sleep health in adults aged 45 years and older in China

Outdoor air pollution has been linked to poor sleep health, but limited studies have investigated the relationship between solid cooking fuels and sleep health in adults. Therefore, we analyzed data from the China Health and Retirement Survey (CHARLS), a national survey of about 17,000 residents aged over 45. Participants were restricted to those who participated in CHARLS 2011, 2013 and 2015 (n = 8,668). Sleep health was indicated by self-reported average sleep hours at night and the numbers of unrested days/week in CHARLS 2015. We analyzed cooking fuel types reported and assessed the duration of solid fuels usage as consistent (indicated use in all three surveys or 6 + years) or inconsistent use (indicated use in one or two surveys or 1-4 years). We found consistent use of solid fuels was associated with a shorter sleep duration (OR = 1.17 95% CI 1.01, 1.35 for ≤ 6 h vs. 7-9 h/day) and higher frequencies of feeling unrested (OR = 1.32 95% CI 1.12, 1.55 for ≥ 5 days/week vs. none) compared with cleaner fuels use. The associations for inconsistent solid fuels use and sleep health were in the similar direction but smaller in magnitude. Further research is needed to confirm our findings and evaluate the exposure impact of specific fuel types to inform intervention strategies.

Associations between and risks of trace elements related to skin and liver damage induced by arsenic from coal burning

Long-term exposure to high levels of arsenic has been documented to induce skin and liver damage, affecting hundreds of millions of people. While arsenic-induced skin and liver damage and trace element alterations have been studied, their correlations and risks have not been explained. Based on the above premise, this study included a total of 172 subjects from a coal-burning arsenic poisoning area. The levels of 18 trace elements in hair and six liver function indices in serum were detected, and the associations between and risks of trace elements related to skin and liver damage were analyzed. Finally, the receiver operating characteristic (ROC) curve and areas under the curve (AUC) were used to analyze the diagnostic values of certain trace elements for arsenic-induced skin and liver damage. The results found that a decrease in Se was a risk factor for arsenic-induced skin and liver damage (OR = 8.33 and 1.92, respectively). Furthermore, increases in Al and V were risk factors for arsenic-induced skin damage (OR = 1.05) and liver damage (OR = 13.16), respectively. In addition, the results found that Se and Al possessed certain diagnostic values for arsenic-induced skin damage (AUC = 0.93, 0.80), that Se possessed a diagnostic value for liver damage (AUC = 0.93), and that the combination of Se and Al increased the diagnostic value for skin damage (AUC = 0.96). This study provides an important research basis for further understanding the reasons for arsenic-induced skin and liver damage, for screening and identifying candidate diagnostic biomarkers, and for improving prevention and control strategies for arsenism.

Dynamic evolution analysis of the factors driving the growth of energy-related CO2 emissions in China: An input-output analysis

In recent years, the global greenhouse effect caused by excessive energy-related carbon emissions has attracted more and more attention. In this paper, we studied the dynamic evolution of factors driving China's energy-related CO2 emissions growth from 2007 to 2015 by using energy consumption method and input-output analysis and used the IO-SDA model to decompose the energy carbon emissions. Within the research interval, the results showed that (1) on the energy supply-side, the high carbon energy represented by raw coal was still the main factor to promote the growth of energy-related CO2 emissions. However, the optimization of energy consumption structure is conducive to reducing emissions. Specifically, the high carbon energy represented by raw coal exhibited a downward trend in promoting the increment of energy-related CO2 emissions, while the clean energy represented by natural gas showed an upward trend in promoting the increment of CO2 emissions. It is worth noting that there is still a lot of room for optimization of China's energy consumption structure to reduce emissions. (2) On the energy demand-side, the final demand effect is the main driving force of the growth of carbon emissions from fossil energy. Among them, the secondary industry plays a major role in the final demand effect. The "high carbonization" of the final product reflects the characteristics of China's high energy input in the process of industrialization. At the same time, since the carbon emission efficiency of the tertiary industry and the primary industry is better than that of the secondary industry, actively optimizing the industrial structure is conducive to slowing down the growth of carbon emission brought by the demand effect. (3) The input structure effect is the main restraining factor for the growth of energy carbon emissions, while the energy intensity effect has a slight driving effect on the growth of energy carbon emissions. The results show that China's "extensive" economic growth model has been effectively reversed, but the optimization of fossil energy utilization efficiency is still not obvious, and there is still a large space to curb carbon emissions by improving fossil energy utilization efficiency in the future.

Abundance and sources of benzo[a]pyrene and other PAHs in ambient air in Hong Kong: A review of 20-year measurements (1997-2016)

The polycyclic aromatic hydrocarbon (PAH) family is of environmental concern due to its toxicity, prompting the need of monitoring their long-term trends. Three monitoring programs in Hong Kong report concentrations of ambient PAHs, namely (1) respirable suspending particle (RSP) speciation program that monitored benzo[a]pyrene (BaP) (1997 to March 2000), (2) total suspended particle speciation program that monitored BaP (1997-1999), and (3) toxic air pollutant monitoring program that monitors BaP and 16 other PAHs in the combined gas and particulate phases at two general urban stations once or twice a month since January 1998. In this work, we review all the available PAH measurements in Hong Kong during 1997-2016, with emphasis on the temporal trends of BaP and the other 16 PAHs. PAHs of 5-6 rings exhibit an ambiguous decline trend since 1998, with a negative Sen's slope that is statistically significant. Specifically, BaP was reduced by 78% from 1998 to 2016, with a Sen's slope of -0.013 ng m^-3 year^-1. Correlations of BaP with RSP major species of high source specificity and PAH diagnostic ratios are employed to explore the source origins of PAHs. Our analysis reveals that PAHs mainly come from a combination of vehicular emissions and biomass/coal combustion. The decline trend of PAHs is further found in consistence with the declined particulate matter emissions from vehicular exhaust and biomass/coal combustion. This study fills the data vacancy in the long-term trends of ambient PAHs for the Pearl River Delta region, one of the economically more advanced regions in China.

Respiratory surveillance for coal mine dust and artificial stone exposed workers in Australia and New Zealand: A position statement from the Thoracic Society of Australia and New Zealand

Coal mine lung dust disease (CMDLD) and artificial stone (AS) silicosis are preventable diseases which have occurred in serious outbreaks in Australia recently. This has prompted a TSANZ review of Australia's approach to respiratory periodic health surveillance. While regulating respirable dust exposure remains the foundation of primary and secondary prevention, identification of workers with early disease assists with control of further exposure, and with the aims of preserving lung function and decreasing respiratory morbidity in those affected. Prompt detection of an abnormality also allows for ongoing respiratory specialist clinical management. This review outlines a medical framework for improvements in respiratory surveillance to detect CMDLD and AS silicosis in Australia. This includes appropriate referral, improved data collection and interpretation, enhanced surveillance, the establishment of a nationwide Occupational Lung Disease Registry and an independent advisory group. These measures are designed to improve health outcomes for workers in the coal mining, AS and other dust-exposed and mining industries.

Micro-RNAs: Crossroads between the Exposure to Environmental Particulate Pollution and the Obstructive Pulmonary Disease

Environmental pollution has reached a global echo and represents a serious problem for human health. Air pollution encompasses a set of hazardous substances, such as particulate matter and heavy metals (e.g., cadmium, lead, and arsenic), and has a strong impact on the environment by affecting groundwater, soil, and air. An adaptive response to environmental cues is essential for human survival, which is associated with the induction of adaptive phenotypes. The epigenetic mechanisms regulating the expression patterns of several genes are promising candidates to provide mechanistic and prognostic insights into this. Micro-RNAs (miRNAs) fulfil these features given their ability to respond to environmental factors and their critical role in determining phenotypes. These molecules are present in extracellular fluids, and their expression patterns are organ-, tissue-, or cell-specific. Moreover, the experimental settings for their quantitative and qualitative analysis are robust, standardized, and inexpensive. In this review, we provide an update on the role of miRNAs as suitable tools for understanding the mechanisms behind the physiopathological response to toxicants and the prognostic value of their expression pattern associable with specific exposures. We look at the mechanistic evidence associable to the role of miRNAs in the processes leading to environmental-induced pulmonary disease (i.e., chronic obstructive pulmonary disease).

Association between coal and firewood combustion and hospital admissions and mortality in Chile 2015 - An ecological approach

INTRODUCTION AND OBJECTIVE

Burning coal and firewood generates toxic emissions that are associated with respiratory illness, cardiovascular disease, and even death. The aim of the study is to evaluate the association between county-level prevalence of household coal and firewood use and health outcomes, including total, respiratory, and cardiovascular mortality, as well as total and respiratory hospitalization rates.

MATERIAL AND METHODS

The ecological study included data on the use of household coal and firewood in 139 counties obtained from the 2015 Chilean National Socio-economic Characterization Survey. Total, respiratory, and cardiovascular mortality, as well as total and respiratory hospitalization rates, were obtained from the Department of Health Statistics. Poisson models with robust error variance, Pearson linear correlation coefficients, and scatterplots were used to explore associations between household coal and firewood use and morbidity-mortality, stratifying by geographic zone.

RESULTS

Total, respiratory, and cardiovascular mortality and total and respiratory hospitalization rates were 5.7 per 1,000, 552 per 100,000, 157 per 100,000, 92.5 per 1000, and 8.8 per 1000 inhabitants, respectively. The median prevalence of coal use for residential cooking, heating, or water heating was 3.64%, while the median prevalence of firewood combustion was 12%. In southern counties, age- and gender-adjusted respiratory mortality increased 2.02 (95% CI: 1.17-3.50), 1.5 (95% CI: 1.11-1.89), and 1.76-fold (95% CI: 1.19-2.60) for each percentage increase in household coal and firewood use for heating, cooking and heating water, respectively.

CONCLUSIONS

The prevalence of household coal and firewood used for heating and cooking was positively correlated with respiratory mortality and hospitalization in southern zone counties.

Contamination identification, source apportionment and health risk assessment of trace elements at different fractions of atmospheric particles at iron and steelmaking areas in China

China has the largest share of global iron and steel production, which is considered to play a significant contribution to air pollution. This study aims to investigate trace element contamination at different fractions of particulate matter (PM) at industrial areas in China. Three PM fractions, PM2.1-9.0, PM1.1-2.1 and PM1.1, were collected from areas surrounding iron and steelmaking plants at Kunming, Wuhan, Nanjing and Ningbo in China. Multiple trace elements and their bioavailability, as well as Pb isotopic compositions, were analysed for identification of contaminants, health risk assessment and source apportionment. Results showed that PM particles in the sites near industrial areas were associated with a range of toxic trace elements, specifically As, Cr(VI), Cd and Mn, and posed significant health risks to humans. The isotopic Pb compositions identified that coal and high temperature metallurgical processes in the steelmaking process were the dominant contributors to local air pollution in these sites. In addition to iron and steelmaking activities, traffic emissions and remote pollution also played a contributing role in PM contamination, confirmed by the differences of Pb isotopic compositions at each PM fraction and statistical results from Preference Ranking Organization Method for Enrichment Evaluations (PROMETHEE) and Geometrical Analysis for Interactive Aid (GAIA). The results presented in this study provide a comprehensive understanding of PM emissions at iron and steelmaking areas, which helps to guide subsequent updates of air pollution control guidelines to efficiently minimise environmental footprint and ensure long term sustainability of the industries.

Solid fuels for cooking and tobacco use and risk of major chronic liver disease mortality: a prospective cohort study of 0.5 million Chinese adults

BACKGROUND

Harmful substances in solid fuel and tobacco smoke are believed to enter the bloodstream via inhalation and to be metabolized in the liver, leading to chronic liver damage. However, little is known about the independent and joint effects of solid fuel use and smoking on risks of chronic liver disease (CLD) mortality.

METHODS

During 2004-08, ∼0.5 million adults aged 30-79 years were recruited from 10 areas across China. During a 10-year median follow-up, 2461 CLD deaths were recorded. Multivariable Cox regression yielded adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the individual associations of self-reported long-term cooking fuel and tobacco use with major CLD death.

RESULTS

Overall, 49% reported solid fuel use and 26% smoked regularly. Long-term solid fuel use for cooking and current smoking were associated with higher risks of CLD deaths, with adjusted HRs of 1.26 (95% CI, 1.02-1.56) and 1.28 (1.13-1.44), respectively. Compared with never-smoking clean fuel users, the HRs were 1.41 (1.10-1.82) in never-smoking solid fuel users, 1.55 (1.17-2.06) in regular-smoking clean fuel users and 1.71 (1.32-2.20) in regular-smoking solid fuels users. Individuals who had switched from solid to clean fuels (1.07, 0.90-1.29; for median 14 years) and ex-regular smokers who stopped for non-medical reasons (1.16, 0.95-1.43; for median 10 years) had no evidence of excess risk of CLD deaths compared with clean fuel users and never-regular smokers, respectively.

CONCLUSIONS

Among Chinese adults, long-term solid fuel use for cooking and smoking were each independently associated with higher risks of CLD deaths. Individuals who had stopped using solid fuels or smoking had lower risks.

Ischaemic heart disease and stroke mortality by specific coal type among non-smoking women with substantial indoor air pollution exposure in China

BACKGROUND

Lifetime use of bituminous ('smoky') coal is associated with nearly a 100-fold higher risk of lung cancer mortality compared with anthracite ('smokeless') coal use in rural Xuanwei, China, among women. Risk of mortality from ischaemic heart disease (IHD) and stroke for these coal types has not been evaluated.

METHODS

A cohort of 16 323 non-smoking women in Xuanwei, who were lifetime users of either smoky or smokeless coal, were followed up from 1976 to 2011. We estimated hazard ratios (HRs) and 95% confidence intervals (CI) to evaluate lifetime use of coal types and stoves in the home in relation to risk of IHD and stroke mortality.

RESULTS

Among lifetime users of smokeless coal, higher average exposure intensity (≥4 tons/year vs <2.5 tons/year, HR = 7.9, 95% CI = 3.5-17.8; Ptrend =<0.0001) and cumulative exposure (>64 ton-years vs ≤28 ton-years, HR = 6.5, 95% CI = 1.5-28.3; Ptrend =0.003) during follow-up and over their lifetime was associated with increased IHD mortality, and ventilated stove use dramatically reduced this risk (HR = 0.2, 95% CI 0.1-0.5). Higher cumulative exposure to smoky coal during follow-up showed positive associations with IHD mortality, but the evidence for other metrics was less consistent compared with associations with smokeless coal use.

CONCLUSIONS

Higher use of smokeless coal, which is burned throughout China and is generally regarded to be a cleaner fuel type, is associated with IHD mortality. Use of cleaner fuels or stove interventions may be effective in reducing the increasing burden of IHD in developing regions that currently rely on smokeless coal for cooking and heating.

Analysis of pulverized tectonic coal gas expansion energy in underground mines and its influence on the environment

Production of a large amount of gas during outbursts will cause greenhouse effects, which will impact the atmospheric environment. In this study, some inherent properties of pulverized tectonic coal were investigated. The results indicate that tectonic coal was more broken and exhibited a higher gas adsorption volume. No obvious changes were found in the micropore and mesopore volumes, whereas the macropore volume and pulverized tectonic coal porosity were significantly increased compared with those of intact coal. Additionally, the initial gas desorption capacities of pulverized tectonic coal were enhanced by tectonism, which might be related to the development of macropore structures and porosity. Analysis of gas expansion energy at the same particle size showed that the values increased with the increasing pressure. Pulverized tectonic coal had a higher gas expansion energy, which could result in a larger outburst of potential energy. Almost all outbursts occurred in tectonic development zones and released a large amount of gas, which greatly damaged the ecological environment. From the perspective of environmental protection, attention should be paid to gas control in the tectonic development zone.

Source apportionment of airborne PCDD/F at industrial and urban sites in Busan, South Korea

Long-term atmospheric measurement of 17 total (gaseous and particulate) polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) has been made from 2007 to 2016 at five industrial and urban sites in Busan, South Korea, based on their persistence, bioaccumulation, and toxicity. In the present study, two pooled datasets covering a combination of 2 industry sites and 3 urban sites have been subjected to positive matrix factorization (PMF) to identify and quantify the major sources of PCDD/Fs. Additionally, PMF has been applied to the industrial urban dataset consisting of both polycyclic aromatic hydrocarbons (PAHs) and PCDD/Fs. The results show that the sum of PCDD/F mass (Σ17PCDD/Fs) at the industrial sites is determined by five major sources: non-ferrous metal production (33.7%), diesel vehicle emissions (30.2%), ferrous metal production (22.4%), other industrial emissions (11.1%), and traffic emissions (2.6%), while the PAH mass (Σ16PAHs) is predominantly associated with emissions from coal combustion, followed by traffic emissions. At the urban sites, the largest contribution to the Σ17PCDD/Fs was observed from transported emissions being emitted from metallurgical industry (75.5%), followed by diesel vehicle emissions (24.5%). The application of congener-specific toxicity to PCDD/F mass (Σ₁₇fg I-TEQ Sm^-3) indicates enhanced contributions from the ferrous metallurgical emission factor associated with penta- and hexa-chlorinated furans across the study sites.

Distract, delay, disrupt: examples of manufactured doubt from five industries

Manufactured doubt describes the efforts used by organizations or individuals to obscure the harmful effects of their products or actions by manipulating science. Although approaches to do so are widely used, relevant stakeholders are often unaware of these tactics. Here, we examine the strategies used in five cases of manufactured doubt: tobacco and adverse health; coal and black lung; Syngenta and the herbicide atrazine; the sugar industry and cardiovascular disease; and the Marshall Institute and climate change. By describing the tactics used in these cases, effective methods for identifying and countering instances of manufactured doubt can be generated.

The respiratory tract microbiome and its relationship to lung cancer and environmental exposures found in rural china

We previously reported that bacterial diversity in sputum samples from never-smoking women in rural China varied by lung cancer status and household air pollution (HAP) exposure type. Here, we expand on our associations between environmental exposures and respiratory tract microbiota with an additional 90 never-smoking women from Xuanwei, China. DNA from sputum samples of cases (n = 45) and controls (n = 45) was extracted using a multistep enzymatic and physical lysis, followed by a standardized clean up. V1-V2 regions of 16S rRNA genes were Polymerase chain reaction (PCR) amplified. Purified amplicons were sequenced by 454 FLX Titanium pyrosequencing and high-quality sequences were evaluated for diversity and taxonomic membership. In our population of never-smokers, increased risk of lung cancer was associated with lower alpha diversity compared to higher alpha diversity (Shannon: ORhigh = 1.00 [reference], ORmedium = 3.84 [1.02-14.48], ORlow = 3.78 [1.03-13.82]; observed species: ORhigh = 1.00 [reference], ORmedium = 2.37 [0.67-8.48], ORlow = 2.01 [0.58-6.97]; Phylogenetic Diversity (PD) whole tree: ORhigh = 1.00 [reference], ORmedium = 3.04 [0.85-10.92], ORlow = 2.53 [0.72-8.96]), as well as a decreased relative abundance of Fusobacteria (ORhigh = 1.00 [reference], ORmedium = 1.24 [0.42-3.66], ORlow = 2.01 [0.63-6.44], ptrend = 0.03). Increasing alpha diversity was associated with smoky coal use compared to clean fuel use among all subjects (observed species, P = 0.001; PD whole tree, P = 0.006; Shannon, P = 0.0002), as well as cases (observed species, P = 0.02; PD whole tree, P = 0.03; Shannon, P = 0.03) and controls (observed species, P = 0.01; PD whole tree, P = 0.05; Shannon, P = 0.002). Increased diversity was also associated with presence of livestock (observed species, P = 0.02; PD whole tree, P = 0.02; Shannon, P = 0.03) in the home for cases. Our study is the first to report that decreased microbial diversity is associated with risk of lung cancer. Larger studies are necessary to elucidate the direct and indirect effects attributed to the disease-specific, HAP-specific, and animal-specific associations. Environ. Mol. Mutagen. 2019. © 2019 Wiley Periodicals, Inc.

Prediction of the length of service at the onset of coal workers' pneumoconiosis based on neural network

Three environmental parameters, i.e. dust concentrations, dust dispersion, and free silica content, were introduced into the traditional indices of the neural network model in order to construct a new prediction index and explore a new method for preventing the incidence of pneumoconiosis with intelligent accuracy and universality. Data of the pneumoconiosis patients from Huabei Mining Group (HBMG) of China from 1980 to 2017 were collected. SPSS22.0 was used to develop the combined models based on Back Propagation (BP) neural network model, Radial Basis Function (RBF) neural network model, and Multiple Linear Regression (MLR) model. The paired sample t-test was performed between the real and predicted values. According to this model, it was predicted that 382 coal workers in HBMG were likely to suffer from pneumoconiosis in 2022 and the incidence rate was 4.48%. It is necessary to take prevention measures and transfer these workers from their current positions. In four combined models, the BP-MLR combined model achieved the optimal error parameters and the most accurate prediction. This study provided a scientific basis for effective control and prevention of the incidence of the pneumoconiosis.

Biomass fuel as a risk factor for esophageal squamous cell carcinoma: a systematic review and meta-analysis

BACKGROUND

The link between use of solid biomass fuel (wood, charcoal, coal, dung, and crop residues) for cooking and/or heating and esophageal squamous cell carcinoma (ESCC) is inconclusive.

OBJECTIVE

We systematically reviewed the literature and performed a meta-analysis to determine whether cooking fuel type influences esophageal squamous cell carcinoma.

METHODS

We searched MEDLINE, EMBASE, Web of Knowledge and Cochrane Database of Systematic Reviews for studies investigating cooking fuel and ESCC from 2000 until March 2019. We performed random effects meta-analysis stratified by the continent, World Bank's country income classifications and fuel type and calculated pooled odds ratios and 95% CIs for the risk of esophageal squamous cell carcinoma in biomass fuel users compared with non-users.

RESULTS

Our analysis included 16 studies (all case-control) with 16,189 participants (5233 cases and 10,956 controls) that compared risk of ESCC among those using nonsolid fuels and biomass fuels. We found use of biomass fuel was associated with Esophageal squamous cell carcinoma with a pooled odds ratio (OR) 3.02 (95% CI 2.22, 4.11, heterogeneity (I2) = 79%). In sub-group analyses by continent, Africa (OR 3.35, 95%CI 2.34, 4.80, I2 = 73.4%) and Asia (OR 3.08, 95%CI 1.27, 7.43, I2 = 81.7%) had the highest odds of ESCC. Use of wood as fuel had the highest odds of 3.90, 95% CI 2.25, 6.77, I2 = 63.5%). No significant publication bias was detected.

CONCLUSIONS

Biomass fuel is associated with increased risk of Esophageal squamous cell carcinoma. Biomass fuel status should be considered in the risk assessment for Esophageal squamous cell carcinoma.

Impact of Coal-fired Power Plant Emissions on Children's Health: A Systematic Review of the Epidemiological Literature

Coal-based energy production is the most utilized method of electricity production worldwide and releases the highest concentration of gaseous, particulate, and metallic pollutants. This article aims to systematically review the public health impact of coal-fired power plant emissions on children’s health. PubMed, Web of Science, and Toxline databases were queried for the past 20 years. Inclusion criteria included original scientific articles with (a) coal-fired power plant exposure assessment, (b) at least one primary pediatric health outcome, and (c) assessment of potential sources of confounding and bias. Only morbidity and mortality studies were included; economic analysis and risk assessment studies without a primary health outcome were not included. Of 513 articles initially retrieved, 17 epidemiological articles were included in the final systematic review after screening and eligibility. The articles reviewed showed a statistically significant adverse effect on pediatric neurodevelopment; birth weight and pediatric respiratory morbidity was associated with exposure to coal-fired power plant emissions, primarily particulate matter and polyaromatic hydrocarbon exposure. There is a lack of consistency of exposure assessment and inadequate control of significant potential confounders such as social economic status. Future research should focus on improving exposure assessment models with an emphasis on source-apportionment and geographic information system methods to model power plant-specific emissions.

Solid Fuel Use and Incident COPD in Chinese Adults: Findings from the China Kadoorie Biobank

BACKGROUND

Solid fuels are widely used in China. Household air pollution from the burning of solid fuels may increase the risk of chronic obstructive pulmonary disease (COPD), but prospective evidence is limited.

OBJECTIVES

We examined the association of solid fuel use for cooking and heating with the risk of COPD in a prospective cohort study.

METHODS

Participants were from the China Kadoorie Biobank. Current and previous fuels used for household cooking and heating were self-reported at baseline in 2004–2008. In the present study, "solid fuels" refers to coal and wood, whereas "cleaner fuels" refers to energy sources that presumably produce lower levels of indoor pollution, including electricity, gas, and central heating. A total of 475,827 adults 30–79 y of age without prevalent COPD were followed through the end of 2015. We used adjusted Cox regression models to estimate hazard ratios for COPD.

RESULTS

Over 9.1 y of follow-up, 9,835 incident COPD cases were reported. Compared with the use of cleaner fuels for cooking, using coal and wood for cooking was positively associated with COPD, with fully adjusted HRs of 1.06 (95% CI: 0.98, 1.15) and 1.14 (95% CI: 1.06, 1.23), respectively. Adjusted HRs for heating with coal and wood were 1.16 (95% CI: 1.04, 1.29) and 1.21 (95% CI: 1.09, 1.35), respectively. The positive association between cooking with solid fuel and COPD appeared to be limited to women and never- (vs. ever-) smokers. COPD risk increased with a higher number of years of solid fuel use for heating and wood use for cooking.

CONCLUSIONS

The use of solid fuel for cooking and heating was associated with the increased risk of COPD in this prospective cohort study. Studies with more accurate exposure assessment are needed to confirm the association. https://doi.org/10.1289/EHP2856.

Air quality and health benefits from potential coal power plant closures in Texas

As power production from renewable energy and natural gas grows, closures of some coal-fired power plants in Texas become increasingly likely. In this study, the potential effects of such closures on air quality and human health were analyzed by linking a regional photochemical model with a health impacts assessment tool. The impacts varied significantly across 13 of the state's largest coal-fired power plants, sometimes by more than an order of magnitude, even after normalizing by generation. While some power plants had negligible impacts on concentrations at important monitors, average impacts up to 0.5 parts per billion (ppb) and 0.2 µg/m³ and maximum impacts up to 3.3 ppb and 0.9 µg/m³ were seen for ozone and fine particulate matter (PM_2.5), respectively. Individual power plants impacted average visibility by up to 0.25 deciviews in Class I Areas. Health impacts arose mostly from PM_2.5 and were an order of magnitude higher for plants that lack scrubbers for SO₂. Rankings of health impacts were largely consistent across the base model results and two reduced form models. Carbon dioxide emissions were relatively uniform, ranging from 1.00 to 1.26 short tons/MWh, and can be monetized based on a social cost of carbon. Despite all of these unpaid externalities, estimated direct costs of each power plant exceeded wholesale power prices in 2016. Implications: While their CO₂ emission rates are fairly similar, sharply different NO_x and SO₂ emission rates and spatial factors cause coal-fired power plants to vary by an order of magnitude in their impacts on ozone, particulate matter, and associated health and visibility outcomes. On a monetized basis, the air pollution health impacts often exceed the value of the electricity generated and are of similar magnitude to climate impacts. This suggests that both air pollution and climate should be considered if externalities are used to inform decision making about power-plant dispatch and retirement.

Fine particle-bound polycyclic aromatic hydrocarbons (PAHs) at an urban site of Wuhan, central China: Characteristics, potential sources and cancer risks apportionment

Levels, compositions, sources, and cancer risks of fine particle (PM_2.5)-bound PAHs were investigated at an urban site of Wuhan, Central China. Totally 115 PM_2.5 samples collected during four seasons from 2014 to 2015 were analyzed for 16 USEPA priority PAHs. The annual average of PM_2.5 and total PAHs were 106 ± 41.7 μg m^-3 and 25.1 ± 19.4 ng m^-3, respectively. The seasonal levels of PM_2.5 and PAHs varied in a similar trend, with the highest concentrations in winter and the lowest in summer. PM_2.5-bound PAHs under different pollution level was discussed and the highest average PAH levels were found at a moderate (115-150 μg m^-3) air quality level. Three sources including coal combustion and biomass burning, petrogenic source, and vehicle emissions were extracted and quantified by the positive matrix factorization (PMF) model, accounting for 22.7 ± 21.3%, 34.4 ± 29.0% and 42.9 ± 31.3% of the total PAHs, respectively. The potential source contribution function (PSCF) and the concentration-weighted trajectory (CWT) were combined to explore the geographic origins of PAHs. The spatial distributions of coal combustion and biomass burning, petrogenic source, and vehicle emissions were well correlated with medium molecular weight (MMW), low molecular weight (LMW) and high molecular weight (HMW) PAHs, respectively. Results of PSCF and CWT indicated that the long-distance transport form north of Wuhan as far as northern and eastern of China was higher than that from the southern China while the contribution of local areas was higher than those from the long-range transport. The overall lifetime lung cancer risk (LLCR) via inhalation exposure to PM_2.5-bound PAHs was estimated as 3.03 × 10^-4, with vehicle emissions contributed 57.1% (1.6 × 10^-4) to the total risk on average, followed by coal combustion and biomass burning (31.0%, 9.6 × 10^-5), and petrogenic source (11.9%, 3.6 × 10^-5).

Solid Fuel Use and Risks of Respiratory Diseases. A Cohort Study of 280,000 Chinese Never-Smokers

RATIONALE

Little evidence from large-scale cohort studies exists about the relationship of solid fuel use with hospitalization and mortality from major respiratory diseases.

OBJECTIVES

To examine the associations of solid fuel use and risks of acute and chronic respiratory diseases.

METHODS

A cohort study of 277,838 Chinese never-smokers with no prior major chronic diseases at baseline. During 9 years of follow-up, 19,823 first hospitalization episodes or deaths from major respiratory diseases, including 10,553 chronic lower respiratory disease (CLRD), 4,398 chronic obstructive pulmonary disease (COPD), and 7,324 acute lower respiratory infection (ALRI), were recorded. Cox regression yielded adjusted hazard ratios (HRs) for disease risks associated with self-reported primary cooking fuel use.

MEASUREMENTS AND MAIN RESULTS

Overall, 91% of participants reported regular cooking, with 52% using solid fuels. Compared with clean fuel users, solid fuel users had an adjusted HR of 1.36 (95% confidence interval, 1.32-1.40) for major respiratory diseases, whereas those who switched from solid to clean fuels had a weaker HR (1.14, 1.10-1.17). The HRs were higher in wood (1.37, 1.33-1.41) than coal users (1.22, 1.15-1.29) and in those with prolonged use (≥40 yr, 1.54, 1.48-1.60; <20 yr, 1.32, 1.26-1.39), but lower among those who used ventilated than nonventilated cookstoves (1.22, 1.19-1.25 vs. 1.29, 1.24-1.35). For CLRD, COPD, and ALRI, the HRs associated with solid fuel use were 1.47 (1.41-1.52), 1.10 (1.03-1.18), and 1.16 (1.09-1.23), respectively.

CONCLUSIONS

Among Chinese adults, solid fuel use for cooking was associated with higher risks of major respiratory disease admissions and death, and switching to clean fuels or use of ventilated cookstoves had lower risk than not switching.

Household coal combustion, indoor air pollutants, and circulating immunologic/inflammatory markers in rural China

The study aim was to investigate whether household bituminous ("smoky") coal use and personal exposure to combustion emissions were associated with immunologic/inflammatory marker levels. A cross-sectional study of healthy never-smoking women from rural Xuanwei and Fuyuan, China was conducted, which included 80 smoky coal and 14 anthracite ("smokeless") coal users. Personal exposure to fine particulate matter (PM_2.5) and benzo[a]pyrene (BaP) was assessed using portable devices, while 67 circulating plasma immunologic/inflammatory markers were measured using multiplex bead-based assays. Multivariable linear regression models were employed to estimate associations between smoky coal versus smokeless coal use, indoor air pollutants, and immunologic/inflammatory markers. Six markers were altered among smoky coal users compared to smokeless coal, including significantly decreased interferon-inducible T-cell alpha chemoattractant (CXCL11/I-TAC), and increased serum amyloid P component (SAP). CXCL11/I-TAC was previously found to be reduced in workers exposed to high levels of diesel engine exhaust, which exhibits similar constituents as coal combustion emissions. Further, there was evidence that elevated PM_2.5 and BaP exposure was associated with significantly diminished levels of the serum amyloid A (SAA); however, the false discovery rates (FDRs) were >0.2 after accounting for multiple comparisons. Inflammatory processes may thus mediate the carcinogenic effects attributed to smoky coal emissions.

PKC θ-mediated Ca2+/NF-AT signalling pathway may be involved in T-cell immunosuppression in coal-burning arsenic-poisoned population

Arsenic poisoning is a worldwide endemic disease that affects thousands of people. Growing evidence from animal, cell, and human studies indicates that arsenic has deleterious effects on the immune system. The present investigation is a population-based study that observed changes in the proliferation of human T-cells and IL-2 and INF-γ mRNA expression. Our results show that coal-burning arsenic can cause T-cell immunosuppression in the population, and participates in the occurrence and development of arsenic poisoning. In addition, we analyzed the intracellular calcium index, expression of protein kinase C theta (PKC θ) and phosphorylated PKC θ, and the DNA-binding activity of NF-AT in peripheral blood mononuclear cells (PBMCs). Our analysis demonstrates that the PKC θ-mediated Ca²⁺/NF-AT signalling pathway may be involved in the T-cell immunosuppression of coal-burning arsenic-poisoned population. This study provides important data for a mechanistic understanding of endemic arsenic poisoning.

[Risk Factors of Lung Cancer in Xuanwei, Yunnan Province, China]

BACKGROUND

Since 1970s, Xuanwei in Yunnan province has been one of the towns with highest lung cancer mortality in China. Moreover, the characters of high female lung cancer mortality and sub-regional clustering high lung cancer mortality have not changed. In this study, we further described the exposure situation of risk factors of lung cancer in Xuanwei nowadays, in order to explore the trend of the distribution of lung cancer there.

METHODS

Firstly we divided the 26 towns of Xuanwei city to high-, median- and low- lung cancer areas by the lung cancer mortality in 2010-2012. We chose 2 towns within each area according to topography and orientation, and randomly picked 4 villages in each town to be our study area. We did a questionnaire about lung cancer related risk factors upon the sample population in the study area. We calculated the exposure percentages of each risk factor, in whole sample population and subgroups, for nowadays and for 10 years ago (only living environmental risk factors), and compared them between areas or time points using standardized rates and the statistical test of standardized rate comparison, or chi-square test.

RESULTS

65%-80% male in the study area has a history of smoking; 60%-90% non-smoker has been exposed to second hand smoke. These situations are worse in high and median lung cancer areas. 50% male in median lung cancer area have coal mining work experience, which is 2 times of the percentages in the other two areas; while 15%-25% people in high lung cancer area have other occupational exposure history to particulate air pollution, which is 3-5 times of the percentages in the other two areas. From ten years ago until nowadays, 80% families in median lung cancer area use 2 tons or more smoky coal per year; more than 90% families burn coal for household heating; more than 60% families suffer from smog in the kitchen during cook; 60% families most frequently use stove in the ground with chimney. Only 20% families in high lung cancer area now use 2 tons or more smoky coal per year. Now 50%-75% families in the study area use 700 kilowatt-hours of electricity per year, much more than ten years ago. 80% residents in low lung cancer area eat fatty or pickled or smoked food at least 3 days per week; while in high and median lung cancer areas the percentages are 50%-60%.

CONCLUSIONS

According to data obtained in this survey, current distribution of smoky coal use has differed from the distribution of high-, median- and low- lung cancer areas. Tobacco use and second hand smoke, the use of smoky coal and occupational exposure to particulate matters could be the main risk factors for lung cancer in Xuanwei now. The relations between lung cancer and stove type, dietary habit and so on deserve further study.

Domestic solid fuel combustion in an adult population in Nigeria: A cross sectional analysis of association with respiratory symptoms, quality of life and lung function

BACKGROUND AND OBJECTIVES

We examined the association of respiratory symptoms, health status, and lung function with the use of solid fuel (wood, charcoal, coal or crop residue) for cooking or heating in a predominantly non-smoking population.

METHODS

Using the protocol of the Burden of Obstructive Lung Diseases (BOLD) initiative, we collected representative population data using questionnaires and spirometry tests. We categorized solid fuel use into 'never user', 'ex user' and 'current user' based on responses to the survey. We developed regression models to evaluate the relation between use of solid fuel and the prevalence of respiratory symptoms, quality of life and lung function adjusting for confounding variables.

RESULTS

Out of 1147 respondents with complete information on domestic fuel type, 33% were 'never-users', 19% were 'ex-users' while 48% reported current use of solid fuel for domestic cooking and/or indoor heating. Compared with never-users, current solid fuel users were more likely to report cough (OR: 1.7, 95% CI: 1.0, 2.9), cough or phlegm (OR: 1.6, 95% CI: 1.0, 2.5) and the association was stronger among women (OR: 3.0, 95% CI: 1.3, 7.1 and OR: 2.3, 95% CI: 1.1, 5.2, respectively). Current solid fuel users also had lower mental health status (coefficient: ?1.5, 95% CI: ?2.8, - 0.2) compared with the group of never-users. Current or previous domestic use of solid fuels for cooking or heating was not associated with higher prevalence of chronic airflow obstruction (FEV₁/FVC < LLN).

CONCLUSIONS

Using solid fuel for domestic cooking or heating was associated with a higher risk of cough or phlegm and a lower mental quality of life. However we found no significant effect in the prevalence of chronic airflow obstruction in Ife, Nigeria.