Assessment of DNA damage in coal open-cast mining workers using the cytokinesis-blocked micronucleus test and the comet assay

Genetic damage among children living in agricultural areas in the North of Colombia

In recent years, the use of pesticides has increased considerably for pest control and to improve agricultural production. The rural areas of several municipalities of department of Cordoba, north of Colombia, are highly dependent on agriculture. In this study, a questionnaire and field observations about pesticide use and genotoxic damage through the comet assay in peripheral blood lymphocytes of children who live near crop fields was evaluated. Damage Index for Comet Assay (DICA) of five children populations exposed to pesticides (mean of 94.73±53.95 for the municipality of Monteria, the higher damage in this study) were significantly Higher than control children population (mean of 7.56±7.39). Results showed the damage index in children exposed group was higher than in the control group. An inadequate management of pesticides, as well as incorrect disposal of toxic wastes was observed in the study zone.

The Comet Assay as a Tool in Human Biomonitoring Studies of Environmental and Occupational Exposure to Chemicals-A Systematic Scoping Review

Biomonitoring of human populations exposed to chemical substances that can act as potential mutagens or carcinogens, may enable the detection of damage and early disease prevention. In recent years, the comet assay has become an important tool for assessing DNA damage, both in environmental and occupational exposure contexts. To evidence the role of the comet assay in human biomonitoring, we have analysed original research studies of environmental or occupational exposure that used the comet assay in their assessments, following the PRISMA-ScR method (preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews). Groups of chemicals were designated according to a broad classification, and the results obtained from over 300 original studies (n = 123 on air pollutants, n = 14 on anaesthetics, n = 18 on antineoplastic drugs, n = 57 on heavy metals, n = 59 on pesticides, and n = 49 on solvents) showed overall higher values of DNA strand breaks in the exposed subjects in comparison with the unexposed. In summary, our systematic scoping review strengthens the relevance of the use of the comet assay in assessing DNA damage in human biomonitoring studies.

Micronuclei frequency and exposure to chemical mixtures in three Colombian mining populations

The Colombian mining industry has witnessed significant growth. Depending on the scale and mineral extracted, complex chemical mixtures are generated, impacting the health of occupationally exposed populations and communities near mining projects. Increasing evidence suggests that chromosomal instability (CIN) is an important link between the development of certain diseases and exposure to complex mixtures. To better understand the effects of exposure to complex mixtures we performed a biomonitoring study on 407 healthy individuals from four areas: three located in municipalities exploiting different-scale mining systems and a reference area with no mining activity. Large, medium, and small-scale mining systems were analyzed in Montelibano (Córdoba), artisanal and small-scale mining (ASGM) in Nechí (Antioquia), and a closed mining system in Aranzazu (Caldas). The reference area with no mining activity was established in Montería (Córdoba). ICP-MS measured multi-elemental exposure in hair, and CIN was evaluated using the cytokinesis-block micronucleus technique (MNBN). Exposure to mixtures of chemical elements was comparable in workers and residents of the mining areas but significantly higher compared to reference individuals. In Montelibano, increased MNBN frequencies were associated with combined exposure to Se, Hg, Mn, Pb, and Mg. This distinct pattern significantly differed from other areas. Specifically, in Nechí, Cr, Ni, Hg, Se, and Mg emerged as the primary contributors to elevated frequencies of MNBN. In contrast, a combination of Hg and Ni played a role in increasing MNBN in Aranzazu. Interestingly, Se consistently correlated with increased MNBN frequencies across all active mining areas. Chemical elements in Montelibano exhibit a broader range compared to other mining zones, reflecting the characteristics of the high-impact and large-scale mining in the area. This research provides valuable insights into the effects of exposure to chemical mixtures, underscoring the importance of employing this approach in the risk assessment of communities, especially those from residential areas.

The dangerous link between coal dust exposure and DNA damage: unraveling the role of some of the chemical agents and oxidative stress

Exposure to coal mining dust poses a substantial health hazard to individuals due to the complex mixture of components released during the extraction process. This study aimed to assess the oxidative potential of residual coal mining dust on human lymphocyte DNA and telomeres and to perform a chemical characterization of coal dust and urine samples. The study included 150 individuals exposed to coal dust for over ten years, along with 120 control individuals. The results revealed significantly higher levels of DNA damage in the exposed group, as indicated by the standard comet assay, and oxidative damage, as determined by the FPG-modified comet assay. Moreover, the exposed individuals exhibited significantly shorter telomeres compared to the control group, and a significant correlation was found between telomere length and oxidative DNA damage. Using the PIXE method on urine samples, significantly higher concentrations of sodium (Na), phosphorus (P), sulfur (S), chlorine (Cl), potassium (K), iron (Fe), zinc (Zn), and bromine (Br) were observed in the exposed group compared to the control group. Furthermore, men showed shorter telomeres, greater DNA damage, and higher concentrations of nickel (Ni), calcium (Ca), and chromium (Cr) compared to exposed women. Additionally, the study characterized the particles released into the environment through GC-MS analysis, identifying several compounds, including polycyclic aromatic hydrocarbons (PAHs) such as fluoranthene, naphthalene, anthracene, 7H-benzo[c]fluorene, phenanthrene, pyrene, benz[a]anthracene, chrysene, and some alkyl derivatives. These findings underscore the significant health risks associated with exposure to coal mining dust, emphasizing the importance of further research and the implementation of regulatory measures to safeguard the health of individuals in affected populations.

Genotoxicity and mutagenicity in blood and drinking water induced by arsenic in an impacted gold mining region in Colombia

Arsenic (As) is one of the most dangerous substances that can affect human health and long-term exposure to As in drinking water can even cause cancer. The objective of this study was to investigate the concentrations of total As in the blood of inhabitants of a Colombian region impacted by gold mining and to evaluate its genotoxic effect through DNA damage by means of the comet assay. Additionally, the concentration of As in the water consumed by the population as well as the mutagenic activity of drinking water (n = 34) in individuals were determined by hydride generator atomic absorption spectrometry and the Ames test, respectively. In the monitoring, the study population was made up of a group of 112 people, including inhabitants of four municipalities: Guaranda, Sucre, Majagual, and San Marcos from the Mojana region as the exposed group, and Montería as a control group. The results showed DNA damage related to the presence of As in blood (p < 0.05) in the exposed population, and blood As concentrations were above the maximum allowable limit of 1 μg/L established by the ATSDR. A mutagenic activity of the drinking water was observed, and regarding the concentrations of As in water, only one sample exceeded the maximum permissible value of 10 μg/L established by the WHO. The intake of water and/or food containing As is potentially generating DNA damage in the inhabitants of the Mojana region, which requires surveillance and control by health entities to mitigate these effects.

Analyses of oxidative DNA damage among coal vendors via single cell gel electrophoresis and quantification of 8-hydroxy-2'-deoxyguanosine

Looking at the development status of Nigeria and other developing nations, most low-income and rural households often use coal as a source of energy which necessitates its trade very close to the communities. Moreover, the effects of exposure to coal mining activities are rarely explored or yet to be studied, not to mention the numerous street coal vendors in Nigeria. This study investigated the oxidative stress levels in serum and urine through the biomarker 8-OHdG and DNA damage via single cell gel electrophoresis (alkaline comet assay). Blood and urine levels of 8-OHdG from 130 coal vendors and 130 population-based controls were determined by ELISA. Alkaline comet assay was also performed on white blood cells for DNA damage. The average values of 8-OHdG in serum and urine of coal vendors were 22.82 and 16.03 ng/ml respectively, which were significantly greater than those detected in controls (p < 0.001; 15.46 and 10.40 ng/ml of 8-OHdG in serum and urine respectively). The average tail length, % DNA in tail and olive tail moment were 25.06 μm, 18.71% and 4.42 respectively for coal vendors. However, for controls, the average values were 4.72 μm, 3.63% and 1.50 for tail length, % DNA in tail and olive tail moment respectively which were much lower than coal vendors (p < 0.001). Therefore, prolonged exposure to coal dusts could lead to higher serum and urinary 8-OHdG and significant DNA damage in coal vendors observed in tail length, % DNA in tail, and olive tail moment by single cell gel electrophoresis. It is therefore established that coal vendors exhibit a huge risk from oxidative stress and assessment of 8-OHdG with single cell gel electrophoresis has proven to be a feasible tool as biomarkers of DNA damage.

Exposure to coal mining can lead to imbalanced levels of inorganic elements and DNA damage in individuals living near open-pit mining sites

Coal mining activities are considered harmful to living organisms. These activities release compounds to the environment, such as polycyclic aromatic hydrocarbons (PAHs), metals, and oxides, which can cause oxidative damage to DNA. In this study, we compared the DNA damage and the chemical composition of peripherical blood of 150 individuals exposed to coal mining residues and 120 non-exposed individuals. Analysis of coal particles revealed the presence of elements such as copper (Cu), aluminum (Al), chrome (Cr), silicon (Si) and iron (Fe). The exposed individuals in our study had significant concentrations of Al, sulfur (S), Cr, Fe, and Cu in their blood, as well as hypokalemia. Results from the enzyme-modified comet assay (FPG enzyme) suggest that exposure to coal mining residues caused oxidative DNA damage, particularly purine damage. Furthermore, particles with a diameter of <2.5 μm indicate that direct inhalation could promote these physiological alterations. Finally, a systems biology analysis was performed to investigate the effects of these elements on DNA damage and oxidative stress pathways. Interestingly, Cu, Cr, Fe, and K are key nodes that intensely modulate these pathways. Our results suggest that understanding the imbalance of inorganic elements caused by exposure to coal mining residues is crucial to understanding their effect on human health.

Analysis of the cytotoxic and genotoxic effects in a population chronically exposed to coal mining residues

During coal mining activities, many compounds are released into the environment that can negatively impact human health. Particulate matter, polycyclic aromatic hydrocarbons (PAHs), metals, and oxides are part of the complex mixture that can affect nearby populations. Therefore, we designed this study to evaluate the potential cytotoxic and genotoxic effects in individuals chronically exposed to coal residues from peripheral blood lymphocytes and buccal cells. We recruited 150 individuals who lived more than 20 years in La Loma-Colombia and 120 control individuals from the city of Barranquilla without a history of exposure to coal mining. In the cytokinesis-block micronucleus cytome (CBMN-Cyt) assay, significant differences in the frequency of micronucleus (MN), nucleoplasmic bridge (NPB), nuclear bud (NBUD), and apoptotic cells (APOP) were observed between the two groups. In the buccal micronucleus cytome (BM-Cyt) assay, a significant formation of NBUD, karyorrhexis (KRX), karyolysis (KRL), condensed chromatin (CC), and binucleated (BN) cells was observed in the exposed group. Considering the characteristics of the study group, a significant correlation for CBMN-Cyt was found between NBUD and vitamin consumption, between MN or APOP and meat consumption, and between MN and age. Moreover, a significant correlation for BM-Cyt was found between KRL and vitamin consumption or age, and BN versus alcohol consumption. Using Raman spectroscopy, a significant increase in the concentration of DNA/RNA bases, creatinine, polysaccharides, and fatty acids was detected in the urine of individuals exposed to coal mining compared to the control group. These results contribute to the discussion on the effects of coal mining on nearby populations and the development of diseases due to chronic exposure to these residues.

Chemical Composition and Toxicity of PM10 and PM0.1 Samples near Open-Pit Mines and Coal Power Stations

Particulate matter (PM) <10 μm in size represents an extremely heterogeneous and variable group of objects that can penetrate the human respiratory tract. The present study aimed to isolate samples of coarse and ultrafine PM at some distance from polluting industries (1−1.5 km from the border of open-cast mines). PM was collected from snow samples which allowed the accumulation of a relatively large amount of ultrafine particles (UFPs) (50−60 mg) from five objects: three open-cast mines, coal power plants, and control territories. The chemical composition of PM was examined using absorption spectroscopy, luminescence spectroscopy, high-performance liquid chromatography, X-ray diffraction (XRD), and X-ray fluorescence (XRF) analyses of solid particle material samples. Toxicity was assessed in human MRC-5 lung fibroblasts after 6 h of in vitro exposure to PM samples. The absorption spectra of all the samples contained a wide non-elementary absorption band with a maximum of 270 nm. This band is usually associated with the absorption of dissolved organic matter (DOM). The X-ray fluorescence spectra of all the studied samples showed intense lines of calcium and potassium and less intense lines of silicon, sulfur, chlorine, and titanium. The proliferation of MRC-5 cells that were exposed to PM0.1 samples was significantly (p < 0.01) lower than that of MRC-5 cells exposed to PM10 at the same concentration, except for PM samples obtained from the control point. PM0.1 samples—even those that were collected from control territories—showed increased genotoxicity (micronucleus, ‱) compared to PM10. The study findings suggest that UFPs deserve special attention as a biological agent, distinct from larger PMs.

Environmental exposure to mineral coal and by-products: Influence on human health and genomic instability

Environmental exposure to pollution generated by mining and burning coal is inevitable for people living nearby. Therefore, the aim of this study was to evaluate the influence of coal dust on health conditions and genomic instability of individuals who live near coal mines and thermoelectric power plants, and to relate the results to inorganic elements and inflammatory responses. Thus, we evaluated 284 individuals from four cities in the south of Brazil around a region with coal mines and a thermoelectric power plant (one city was considered a negative control). The results of the Comet assay and Micronucleus (MN) test did not show a genotoxic or mutagenic effect related to environmental exposure to coal, but the inflammatory cytokine tumor necrosis factor-α (TNF-α) was increased in all cities around the power plant when compared to the control conditions. Higher levels of MN were associated with body mass index and cardiovascular risk, and higher levels of Damage Index (DI), TNF-α and interleukin1β (IL-1β) with number of cigarettes/day. Principal component analysis (PCA) was used to integrate DNA damage and inflammatory results with inorganic elements. This study also demonstrated the relationship between zinc and MN, copper, and interleukin10 (IL-10), and among silicon and sulfur with DI and nucleoplasmic bridge. A relationship was also observed between the reduction of inorganic elements and both aging and quality of health. The use of different methodologies and the relationship between the results obtained in these studies, including different lifestyles, can increase the understanding of the interaction between this mineral and the health status of residents of regions affected by coal pollution.

Genetic damage in coal and uranium miners

Mining has a direct impact on the environment and on the health of miners and is considered one of the most hazardous occupations worldwide. Miners are exposed to several occupational health risks, including genotoxic substances, which may cause adverse health effects, such as cancer. This review summarizes the relation between DNA damage and mining activities, focusing on coal and uranium miners. The search was performed using electronic databases, including original surveys reporting genetic damage in miners. Additionally, a temporal bibliometric analysis was performed using an electronic database to create a map of cooccurrence terms. The majority of studies were performed with regard to occupational exposure to coal, whereas genetic damage was assessed mainly through chromosomal aberrations (CAs), micronuclei (MNs) and comet assays. The bibliometric analysis demonstrated associations of coal exposure with silicosis and pneumoconiosis, uranium miners with lung cancer and tumors and some associated factors, such as age, smoking, working time and exposure to radiation. Significantly higher DNA damage in miners compared to nonexposed groups was observed in most of the studies. The timeline reveals that classic biomarkers (comet assay, micronucleus test and chromosomal aberrations) are still important tools to assess genotoxic/mutagenic damage in occupationally exposed miners; however, newer studies concerning genetic polymorphisms and epigenetic changes in miners are being conducted. A major challenge is to investigate further associations between miners and DNA damage and to encourage further studies with miners of other types of ores.

DNA damage assessment with buccal micronucleus cytome assay in Turkish coal miners

The aim of this study was to assess DNA damage in Turkish coal miners with the buccal micronucleus cytome (BMCyt assay as the least invasive and therefore most practical method that may find wider application in coal miner biomonitoring. Buccal epithelial cell samples were taken from 54 coal miners and 42 controls from Zonguldak, Turkey to establish their micronucleus (MN), binucleus (BN), condensed chromatin (CC), karyorrhectic (KHC), karyolytic (KYL), nuclear bud (NBUD), and pyknotic (PYC) frequencies. We also analysed the effects of confounding factors such as age, years of work at the mine, smoking, alcohol drinking, and use of protective equipment on differences in MN frequencies. Two miners had confirmed and three suspect pneumoconiosis, whereas 49 displayed normal chest radiographs. MN, BN, KHC, and NBUD frequencies were significantly higher in coal miners than controls. Years of work at the mine also showed a significant effect on buccal MN frequencies in coal miners, but we found no correlation between MN frequencies and age, smoking, and alcohol consumption. In conclusion, BMCyt assay proved itself an accurate and practical screening method, as it can detect DNA damage much earlier than pneumoconiosis develops.

BACKGROUND RADIATION LEVELS NEAR A MINERAL SAND MINING FACTORY IN SRI LANKA: CORRELATION OF RADIATION MEASUREMENTS WITH MICRONUCLEI FREQUENCY

Lanka Mineral Sands Ltd (LMS) is a company operating in Pulmoddai, Sri Lanka, mining for rare earth minerals along with monazite which contains thorium that emits ionizing gamma and alpha radiation on decay. The objective of the study was to determine the background radiation levels and selected radionuclides and then to correlate these levels with the frequency of micronuclei (MN) among persons residing in the vicinity of LMS. A cross-sectional study was conducted among persons of both sexes between 35 and 45 years of age residing in the vicinity of LMS. Background radiation measurements were obtained by a survey metre, and gamma spectrometry was done on soil samples. Five millilitres of venous blood was drawn for cytokinesis-blocked MN assay. Background radiation levels measured by the survey metre; 232Th, 226Ra and 210Pb mass activities in soil were highest in the samples collected from the LMS. The background radiation measurements positively correlated with MN frequency although the magnitude of the correlation was small (r = 0.176, p = 0.04). This implies that chronic long-term exposure to low-dose radiation may result in genotoxicity. Prospective large-scale studies are recommended to evaluate the long-term effect of exposure to low-dose radiation at Pulmoddai.

Systems chemo-biology analysis of DNA damage response and cell cycle effects induced by coal exposure

Cell cycle alterations are among the principle hallmarks of cancer. Consequently, the study of cell cycle regulators has emerged as an important topic in cancer research, particularly in relation to environmental exposure. Particulate matter and coal dust around coal mines have the potential to induce cell cycle alterations. Therefore, in the present study, we performed chemical analyses to identify the main compounds present in two mineral coal samples from Colombian mines and performed systems chemo-biology analysis to elucidate the interactions between these chemical compounds and proteins associated with the cell cycle. Our results highlight the role of oxidative stress generated by the exposure to the residues of coal extraction, such as major inorganic oxides (MIOs), inorganic elements (IEs) and polycyclic aromatic hydrocarbons (PAH) on DNA damage and alterations in the progression of the cell cycle (blockage and/or delay), as well as structural dysfunction in several proteins. In particular, IEs such as Cr, Ni, and S and PAHs such as benzo[a]pyrene may have influential roles in the regulation of the cell cycle through DNA damage and oxidative stress. In this process, cyclins, cyclin-dependent kinases, zinc finger proteins such as TP53, and protein kinases may play a central role.

DNA repair and metabolic gene polymorphisms affect genetic damage due to diesel engine exhaust exposure

Diesel engine exhaust (DEE) is a complex mixture of toxic gases, halogenated aromatic hydrocarbons, alkyl polycyclic aromatic hydrocarbons, polycyclic aromatic hydrocarbons, benzene derivatives, metals and diesel exhaust particles (DEPs) generated from the incomplete combustion of diesel fuel. Many of the compounds in this mixture can cause oxidative damage to DNA and are considered carcinogenic for humans. Further, chronic DEE exposure increases risks of cardiovascular and pulmonary diseases. Despite these pervasive health risks, there is limited and inconsistent information regarding genetic factors conferring susceptibility or resistance to DEE genotoxicity. The present study evaluated the effects of polymorphisms in two base excision repair (BER) genes (OGG1 Ser326Cys and XRCC1 Arg280His), one homologous recombination (HRR) gene (XRCC3 Thr241Met) and two xenobiotic metabolism genes (GSTM1 and GSTT1) on the genotoxicity profiles among 123 mechanics exposed to workplace DEE. Polymorphisms were determined by PCR-RFLP. In comet assay, individuals with the GSTT1 null genotype demonstrated significantly greater % tail DNA in lymphocytes than those with non-null genotype. In contrast, these null individuals exhibited significantly lower frequencies of binucleated (BN) cells and nuclear buds (NBUDs) in buccal cells than non-null individuals. Heterozygous hOGG1 326 individuals (hOGG1 326 Ser/Cys) exhibited higher buccal cell NBUD frequency than hOGG1 326 Ser/Ser individuals. Individuals carrying the XRCC3 241 Met/Met polymorphism also showed significantly higher buccal cell NBUD frequencies than those carrying the XRCC3 241 Thr/Thr polymorphism. We found a high flow of particulate matter with a diameter of < 2.5 μm (PM_2.5) in the workplace. The most abundant metals in DEPs were iron, copper, silicon and manganese as detected by transmission electron microscopy-energy-dispersive X-ray spectroscopy (TEM-EDX). Scanning electron microscopy (SEM-EDS) revealed particles with diameters smaller than PM_2.5, including nanoparticles forming aggregates and agglomerates. Our results demonstrate the genotoxic effects of DEE and the critical influence of genetic susceptibility conferred by DNA repair and metabolic gene polymorphisms that shed light into the understanding of underlying mechanisms.

Source apportionment of potentially toxic elements in street dust of a coal mining area in Chhattisgarh, India, using multivariate and lead isotopic ratio analysis

Street dust of Korba, Chhattisgarh, an urban industrial hub in one of India's major coal mining areas, has been analysed for profiling and sourcing of Pb and other potentially toxic elements (PTEs). Lead isotopic ratio of dust, coal, diesel, fly ash and human blood of Korba is being reported for the first time in this study. The mean concentrations (in mg/kg) of Al, V, Cr, Fe, Mn, Ni, Cu, Zn, Cd and Pb were higher than World Background soil and Reference soil USA values and decreased in the order of Al (17000) > Fe (7550) > Mn (2740) > Cr (833) > Ni (571) > Zn (231) > Cu (152) > V (145) > Pb (98.6) > U (7.9) > Cd (1.34). About 25% of the sampled dust had Pb I_geo belonging to class IV category of heavy contamination. Dust from industrial areas was highly enriched with Cr, Cu, Pb and Mn, while those from coal mining areas had high mean V concentration. Principal component analysis extracted Al, Fe, Mn, Zn, Pb and U with the highest loading factors in Component 1 indicative of their lithogenic and anthropogenic sources. The lead isotopic ratios of the dust, coal, diesel, fly ash and eight human blood samples clustered linearly in the ²⁰⁷Pb/²⁰⁴Pb vs ²⁰⁸Pb/²⁰⁴Pb and ²⁰⁶Pb/²⁰⁴Pb vs ²⁰⁸Pb/²⁰⁴Pb plots. Airborne lead deposition from diesel-based traffic exhausts and fly ash contributed to the human blood lead level besides coal mining activities. Geospatially, while Pb was mainly concentrated in the residential, industrial and coal-mining areas, Zn and Mn were mainly distributed in the roadside areas of industrial centres.

Biomarkers of susceptibility and effect in car painters exposed to organic solvents

Introduction

Car painters are routinely exposed to organic solvents classified as carcinogenic and mutagenic substances.

Objective

To characterize the population susceptibility and evaluate the genotoxic effects of exposure to organic solvents.

Methods

A cross-sectional study comparing a group of car painters exposed to organic solvents with a non-exposed group. CYP2E1 polymorphisms and the presence of micronuclei in lymphocytes were determined.

Results

One hundred twenty-two workers participated in the study: 62 who worked in car paint shops and were exposed to solvents, and 60 who were not exposed. There were statistically significant differences between the two groups regarding micronucleated cells and nucleoplasmic bridges frequencies (p= 0.042 and p= 0.046, respectively; exact likelihood ratio). Significant differences were found at the interaction between the CYP2E1 genotype c1c1 and occupational exposure to solvents, with higher frequencies of micronuclei (p= 0.013) and micronucleated cells (p= 0.015). However, when the frequencies of micronuclei, micronucleated cells and nucleoplasmic bridges in the exposure group were compared between the c1c1 and c2c2/c1c2 allele groups of the CYP2E1 polymorphism, statistically significant differences were found.

Conclusions

This study confirms that when workers with CYP2E1 polymorphisms, specifically the c1c1 genotype, are exposed to organic solvents, they are more likely to have somatic cell mutations, a condition associated with increased susceptibility to diseases such as cancer.

Pulmonary oxidative stress in wild bats exposed to coal dust: A model to evaluate the impact of coal mining on health

This study aimed to verify possible alterations involving histological and oxidative stress parameters in the lungs of wild bats in the Carboniferous Basin of Santa Catarina (CBSC) state, Southern Brazil, as a means to evaluate the impact of coal dust on the health of wildlife. Specimens of frugivorous bat species Artibeus lituratus and Sturnira lilium were collected from an area free of coal dust contamination and from coal mining areas. Chemical composition, histological parameters, synthesis of oxidants and antioxidant enzymes, and oxidative damage in the lungs of bats were analyzed. Levels of Na, Cl, Cu, and Br were higher in both species collected in the CBSC than in the controls. Levels of K and Rb were higher in A. lituratus, and levels of Si, Ca, and Fe were higher in S. lilium collected in the carboniferous basin. Both bat species inhabiting the CBSC areas exhibited an increase in the degree of pulmonary emphysema compared to their counterparts collected from control areas. Sturnira lilium showed increased reactive oxygen species (ROS) and 2',7'-dichlorofluorescein (DCF) levels, while A. lituratus showed a significant decrease in nitrite levels in the CBSC samples. Superoxide dismutase (SOD) activity did not change significantly; however, the activity of catalase (CAT) and levels of glutathione (GSH) decreased in the A. lituratus group from CBSC compared to those in the controls. There were no differences in NAD(P)H quinone dehydrogenase 1 protein (NQO1) abundance or nitrotyrosine expression among the different groups of bats. Total thiol levels showed a significant reduction in A. lituratus from CBSC, while the amount of malondialdehyde (MDA) was higher in both A. lituratus and S. lilium groups from coal mining areas. Our results suggested that bats, especially A. lituratus, living in the CBSC could be used as sentinel species for harmful effects of coal dust on the lungs.

Intergenerational effects of coal dust on Tribolium castaneum, Herbst

Coal dust is a primary air contaminant from coal mining operations that produces harmful health effects. However, it is unclear to what extent its detrimental properties would impact future generations, and whether alterations in the progenies might be concentration-dependent. The aim of this study was to determine the intergenerational effects of chronic exposure to coal dust on the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), at three life stages. Groups of fifty adult insects were exposed during 30 days at different concentrations of coal dust mixed with ground oats as food substrate (0, 0.25, 0.5, 1.0 and 2.0% weight/weight), both with a particle size <38 μm. The LC₅₀ for F0 insects was 1.07%, whereas for larvae and adults from F1, values were 0.53 and 0.89%, respectively. Pathological findings assessed at F1 revealed a coal dust concentration-dependent frequency of several morphological abnormalities, including larvae without antenna or extremities, lack of T1, T2, T3 legs, loss of urogomphi, and the presence of abnormal protuberances. It was found that a considerable number of F1 larvae derived from parental beetles did not achieve a complete conversion into the next growth stage. Pupae with undeveloped eyes and adults with malformed elytra, as well as necrosis, were recurrently observed at high concentrations. Finally, adults exposed to 1% coal dust overexpressed genes related to oxidative stress (nuclear factor erythroid 2-related factor 2, Nrf2) and synaptic transmission (GABA-gated ion channel, Grd). In short, coal dust particles induced intergenerational effects on T. castaneum, highlighting the need to further study the impact of this airborne pollutant on wildlife and human populations.

Air Pollution Emissions 2008-2018 from Australian Coal Mining: Implications for Public and Occupational Health

Occupational exposure limits for respirable coal dust are based on exposure during working hours, but coal miners may experience additional community-based exposures during nonworking hours. We analyzed Australia National Pollutant Inventory (NPI) data for the years 2008–2018 to estimate air pollutants (metals, nitrogen oxides, particulate matter ≤ 10 micrometers (PM10) and ≤2.5 micrometers (PM2.5)) originating from coal mines. PM10 levels from community-based air monitors in Queensland and New South Wales were also compared between mining and nonmining communities. Results indicated that tons of coal mined increased over the study period, and that levels of particulate matter, metals, and nitrogen oxides increased significantly over time as well. Coal mines accounted for 42.1% of national PM10 air emissions from NPI sites. PM2.5 from coal mines accounted for 19.5% of the national total, metals for 12.1%, and nitrogen oxides for 10.1%. Coal mining occurred in 57 different post codes; the 20 coal-mining post codes with the highest PM10 emissions were home to 160,037 people. Emissions of all studied pollutants were significantly higher from coal mining sites than from other types of NPI sites. Results from community-based air monitoring stations indicated significantly higher population PM10 exposure in coal mining communities than in nonmining communities. The health of the public at large is impacted by coal mining, but to the extent that miners also live near coal mining operations, their total exposure is underestimated by consideration of exposure only during working hours.

The influence of polymorphisms of xenobiotic-metabolizing and DNA repair genes in DNA damage, telomere length and global DNA methylation evaluated in open-cast coal mining workers

Coal plants represent one of the main sources of environmental pollution due to the combustion process of this mineral and the consequent release of gases and particles which, in significant quantities, can lead to a potential risk to health and the environment. The susceptibility of individuals to the genotoxic effects of coal mining can be modulated by genetic variations in the xenobiotic detoxification and DNA repair processes. The aim of this study was to evaluate if xenobiotic metabolism polymorphism, base excision repair polymorphisms and non-homologous end joining repair polymorphism, could modify individual susceptibility to genomic instability and epigenetic alterations induced in workers by occupational exposure to coal. In this study, polymerase chain reaction was used to examine the polymorphic sites. The sample population comprising 70 coal mine workers and 71 workers non-exposed to coal. Our results demonstrated the effect of individual genotypes on different biomarkers evaluated. Significant decrease in % of global DNA methylation were observed in CYP1A1 Val/- exposed individuals compared to CYP1A1 Ile/Ile individuals. Coal workers who carried the XRCC4 Ile/Ile genotype showed decrease NBUD frequencies, while the XRCC4 Thr/- genotype was associated with decrease in Buccal micronucleus cells for the group not exposed. No influence of GSTM1 null, GSTT1 null, GSTP1 Ile105Val, hOGG1 Ser326Cys, XRCC1 Arg194Trp polymorphisms was observed. Thus, the current study reinforces the importance of considering the effect of metabolizing and repair variant genotypes on the individual susceptibility to incorporate DNA damage, as these processes act in a coordinated manner to determine the final response to coal exposure.

Application of the comet assay in human biomonitoring: An hCOMET perspective

The comet assay is a well-accepted biomonitoring tool to examine the effect of dietary, lifestyle, environmental and occupational exposure on levels of DNA damage in human cells. With such a wide range of determinants for DNA damage levels, it becomes challenging to deal with confounding and certain factors are inter-related (e.g. poor nutritional intake may correlate with smoking status). This review describes the effect of intrinsic (i.e. sex, age, tobacco smoking, occupational exposure and obesity) and extrinsic (season, environmental exposures, diet, physical activity and alcohol consumption) factors on the level of DNA damage measured by the standard or enzyme-modified comet assay. Although each factor influences at least one comet assay endpoint, the collective evidence does not indicate single factors have a large impact. Thus, controlling for confounding may be necessary in a biomonitoring study, but none of the factors is strong enough to be regarded a priori as a confounder. Controlling for confounding in the comet assay requires a case-by-case approach. Inter-laboratory variation in levels of DNA damage and to some extent also reproducibility in biomonitoring studies are issues that have haunted the users of the comet assay for years. Procedures to collect specimens, and their storage, are not standardized. Likewise, statistical issues related to both sample-size calculation (before sampling of specimens) and statistical analysis of the results vary between studies. This review gives guidance to statistical analysis of the typically complex exposure, co-variate, and effect relationships in human biomonitoring studies.

Association between DNA damage, dietary patterns, nutritional status, and non-communicable diseases in coal miners

Several negative health effects have been associated with environmental pollution. Coal mining activities are related to DNA damage. However, the impact of lifestyle as well as environmental exposure must be considered when evaluating the extent of DNA damage. The aim of this cross-sectional study was to analyze nutritional status, dietary patterns, and the prevalence of non-communicable diseases (CNCDs) among coal miners as well as to investigate the correlation of these variables with DNA damage. We used a questionnaire to assess demographics, health, and dietary habits. The nutritional status was measured in terms of BMI (body mass index) and DNA damage was assessed by the comet assay. The sample population was composed of 158 coal miners from the largest coal mining company in South of Brazil, and majority of them were classified as overweight (51.3%) or obese (28.5%). Hypertension was the most common CNCD (50.6%) and a majority of these workers consumed all groups of foods three or more times a week. There was a significant positive correlation between BMI and DNA damage (r = 0.1646, p = 0.04) and this association was stronger (r = 0.2556, p = 0.04) in coal miners with some CNCD. There was no significant correlation between dietary patterns and DNA damage in coal miners. These results suggest that the nutritional status and CNCD increase the extent of DNA damage in coal miners. Since this population is at high occupational risk, specific strategies should be designed to improve the health of these workers, aiming to achieve health equity.

Cytotoxic and genotoxic effects in mechanics occupationally exposed to diesel engine exhaust

Diesel engine exhaust (DEE), which is the product of diesel combustion, is considered carcinogenic in humans. It comprises toxic gases, polycyclic aromatic hydrocarbons (PAHs) and particulate matter which can reach the pulmonary parenchyma and trigger various diseases, including cancer. The aim of the present study was to evaluate the potential cytotoxic and genotoxic effects of DEE exposure on peripheral blood and buccal epithelial cells in mechanics occupationally exposed to DEE. We recruited 120 exposed mechanics and 100 non-exposed control individuals. Significant differences were observed between the two groups in terms of percentage of tail DNA and damage index (DI) in the alkaline comet assay; levels of biomarkers by cytokinesis-block micronucleus cytome (CBMN-Cyt) assay; frequency of micronucleus (MN), nucleoplasmic bridge (NPB), nuclear bud (NBUD) and apoptotic cells (APOP) and levels of biomarkers for micronucleus, karyorrhexis (KRX), karyolysis (KRL) and condensed chromatin (CC) by the buccal micronucleus cytome (BM-Cyt) assay. A significant and positive correlation was found between the frequency of MN in lymphocytes and buccal cells in the exposed group. Also, there was a significant correlation between age and percentage of tail DNA and DI in the comet assay, APOP and MN in the CBMN-Cyt assay and NBUD and MN in the BM-Cyt assay. Additionally, we found a positive and significant correlation of MN frequency in lymphocytes and buccal cells and age and MN frequency in lymphocytes with the time of service (years). Regarding lifestyle-related factors, a significant correlation was observed between meat and vitamin consumption and NBUD formation on CBMN-Cyt and between meat consumption and MN formation on CBMN-Cyt. Of the BM-Cyt biomarkers, there was a correlation between alcohol consumption and NBUD formation and between binucleated cell (BN), pyknosis (PYC), CC and KRL occurrence and family cancer history. These results are the first data in Colombia on the cytotoxic and genotoxic effects induced by continuous exposure to DEE and thus showed the usefulness of biomarkers of the comet, CBMN-Cyt and BM-Cyt assays for human biomonitoring and evaluation of cancer risk in the exposed populations.

Genetic damage in human populations at mining sites in the upper basin of the San Jorge River, Colombia

Contamination with mining wastes affects the environmental health and public, especially the human populations that live in these environments. The aim of this study was to evaluate the genotoxicity and levels of mercury (Hg) and arsenic (As) in blood samples from human populations exposed to mining activities in the upper basin of the San Jorge River. A total of 100 individuals participated in the study, 50 as an exposed group (Bocas de Ure = 15 individuals, Mina el Alacrán = 19 individuals, Torno Rojo = 16 individuals) and 50 individuals participated as the control group. Hg and As contents in blood samples were analyzed with atomic absorption spectrophotometry. A comet assay in peripheral blood lymphocytes and a micronucleus (MN) cytome assay (BMCyt) in exfoliated buccal cells were used to assess the effects of exposure to heavy metals on human communities located in mining areas. Higher concentrations of Hg and As were observed in human populations located in mining areas. The comet assay and BMCyt data revealed DNA damage and cell death in human communities located in mining areas. A positive association between blood arsenic and genetic damage was found. These data confirm the public health risk of the population near mining sites. Our findings suggest that populations that live at sites close to mining activities have high contents of heavy metals and genotoxic effects, representing a risk to human health.

Geospatial analysis of residential proximity to open-pit coal mining areas in relation to micronuclei frequency, particulate matter concentration, and elemental enrichment factors

During coal surface mining, several activities such as drilling, blasting, loading, and transport produce large quantities of particulate matter (PM) that is directly emitted into the atmosphere. Occupational exposure to this PM has been associated with an increase of DNA damage, but there is a scarcity of data examining the impact of these industrial operations in cytogenetic endpoints frequency and cancer risk of potentially exposed surrounding populations. In this study, we used a Geographic Information Systems (GIS) approach and Inverse Distance Weighting (IDW) methods to perform a spatial and statistical analysis to explore whether exposure to PM_2.5 and PM₁₀ pollution, and additional factors, including the enrichment of the PM with inorganic elements, contribute to cytogenetic damage in residents living in proximity to an open-pit coal mining area. Results showed a spatial relationship between exposure to elevated concentrations of PM_2.5, PM₁₀ and micronuclei frequency in binucleated (MNBN) and mononucleated (MNMONO) cells. Active pits, disposal, and storage areas could be identified as the possible emission sources of combustion elements. Mining activities were also correlated with increased concentrations of highly enriched elements like S, Cu and Cr in the atmosphere, corroborating its role in the inorganic elements pollution around coal mines. Elements enriched in the PM_2.5 fraction contributed to increasing of MNBN but seems to be more related to increased MNMONO frequencies and DNA damage accumulated in vivo. The combined use of GIS and IDW methods could represent an important tool for monitoring potential cancer risk associated to dynamically distributed variables like the PM.

Association of DNA repair gene polymorphisms with genotoxic stress in underground coal miners

In underground coal mining, numerous harmful substances and ionising radiation pose a major threat to the occupational safety and health of workers. Because cell DNA repair machinery eliminates genotoxic stress conferred by these agents, we examined whether single nucleotide polymorphisms in hOGG1 (rs1052133), XRCC1 (rs25487), ADPRT (rs1136410), XRCC4 (rs6869366) and LIG4 (rs1805388) genes modulate the genotoxic damage assessed by the cytokinesis-block micronucleus assay in lymphocytes from 143 underground coal miners and 127 healthy non-exposed males. We also analyzed models of gene-gene interactions associated with increased cytogenetic damage in coal miners and determined 'protective' and 'risk' combinations of alleles. We showed that miners with the G/G genotype of the hOGG1 (rs1052133) gene had a significantly increased frequency of binucleated lymphocytes with micronuclei (13.17‰, 95% CI = 10.78-15.56) compared to the C/C genotype carriers (10.35‰, 95% CI = 9.59-11.18). In addition, in the exposed group this indicator was significantly increased in carriers of the T/T genotype of the LIG4 (rs1805388) gene compared to miners harbouring the C/T genotype (13.00‰, 95% CI = 10.96-15.04 and 9.69‰, 95% CI = 8.32-11.06, respectively). Using the multifactor dimensionality reduction method, we found the three-locus model of gene-gene interactions hOGG1 (rs1052133) × ADPRT (rs1136410) × XRCC4 (rs6869366) associated with high genotoxic risk in coal miners. These results indicate that the studied polymorphisms and their combinations are associated with cytogenetic status in miners and may be used as molecular predictors of occupational risks in underground coal mines.

Intratracheal instillation of coal and coal fly ash particles in mice induces DNA damage and translocation of metals to extrapulmonary tissues

Continuous exposure to coal mining particles can cause a variety of lung diseases. We aimed to evaluate the outcomes of exposure to detailed characterized coal and coal fly ash (CFA) particles on DNA, lung and extrapulmonary tissues. Coal samples (COAL11 and COAL16) and CFA samples (CFA11 and CFA16) were included in this study. Intending to enhance the combustion process COAL16 was co-fired with a mixture of fuel oil and diesel oil, producing CFA16. Male BALB/c mice were intratracheally instilled with coal and CFA particles. Measurements were done 24h later. Results showed significant rigidity and obstruction of the central airways only for animals acutely exposed to coal particles. The COAL16 group also showed obstruction of the peripheral airways. Mononuclear cells were recruited in all treatment groups and expression of cytokines, particularly TNF-α and IL-1β, was observed. Only animals exposed to COAL16 showed a significant expression of IL-6 and recruitment of polymorphonuclear cells. DNA damage was demonstrated by Comet assay for all groups. Cr, Fe and Ni were detected in liver, spleen and brain, showing the efficient translocation of metals from the bloodstream to extrapulmonary organs. These effects were associated with particle composition (oxides, hydroxides, phosphates, sulfides, sulphates, silciates, organic-metalic compounds, and polycyclic aromatic hidrocarbons) rather than their size. This work provides state of knowledge on the effects of acute exposure to coal and CFA particles on respiratory mechanics, DNA damage, translocation of metals to other organs and related inflammatory processes.

Embryonic exposure to an aqueous coal dust extract results in gene expression alterations associated with the development and function of connective tissue and the hematological system, immunological and inflammatory disease, and cancer in zebrafish

Coal mining is one of the economic activities with the greatest impact on environmental quality. At all stages contaminants are released as particulates such as coal dust. The first aim of this study was to obtain an aqueous coal dust extract and characterize its composition in terms of trace elements by ICP-MS. In addition, the developmental toxicity of the aqueous coal extract was evaluated using zebrafish (Danio rerio) after exposure to different concentrations (0-1000 ppm; μg mL^-1) to establish acute toxicity, morphology and transcriptome changes. Trace elements within the aqueous coal dust extract present at the highest concentrations (>10 ppb) included Sr, Zn, Ba, As, Cu and Se. In addition, Cd and Pb were found in lower concentrations. No significant difference in mortality was observed (p > 0.05), but a delay in hatching was found at 0.1 and 1000 ppm (p < 0.05). No significant differences in morphological characteristics were observed in any of the treatment groups (p > 0.05). Transcriptomic results of zebrafish larvae revealed alterations in 77, 61 and 1376 genes in the 1, 10, and 100 ppm groups, respectively. Gene ontology analysis identified gene alterations associated with the development and function of connective tissue and the hematological system, as well as pathways associated with apoptosis, the cell cycle, transcription, and oxidative stress including the MAPK signaling pathway. In addition, altered genes were associated with cancer; connective tissue, muscular, and skeletal disorders; and immunological and inflammatory diseases. Overall, this is the first study to characterize gene expression alterations in response to developmental exposure to aqueous coal dust residue from coal mining with transcriptome results signifying functions and systems to target in future studies.

Cytogenetic instability in populations with residential proximity to open-pit coal mine in Northern Colombia in relation to PM10 and PM2.5 levels

Epidemiological studies indicate that living in proximity to coal mines is correlated with numerous diseases including cancer, and that exposure to PM₁₀ and PM_2.5 components could be associated with this phenomenon. However, the understanding of the mechanisms by which PM exerts its adverse effects is still incomplete and comes mainly from studies in occupationally exposed populations. The aims of this study were to: (1) evaluate DNA damage in lymphocytes assessing the cytokinesis-block micronucleus cytome assay (CBMN-cyt) parameters; (2) identify aneugenic or clastogenic effects in lymphocytes of exposed populations using CREST immunostaining for micronuclei; (3) evaluate multi-elemental composition of atmospheric particulate matter; and (4) verify relation between the DNA damage and PM_2.5 and PM₁₀ levels around the mining area. Analysis revealed a significant increase in micronuclei frequency in binucleated (MNBN) and mononucleated (MNMONO) cells of individuals with residential proximity to open-pit coal mines compared to residents from non-mining areas. Correlation analysis demonstrated a highly significant association between PM_2.5 levels, MNBN frequencies and CREST+ micronuclei induction in exposed residents. These results suggest that PM_2.5 fraction generated in coal mining activities may induce whole chromosome loss (aneuploidy) preferentially, although there are also chromosome breaks. Analysis of the chemical composition of PM_2.5 by PIXE demonstrated that Si, S, K and Cr concentrations varied significantly between coal mining and reference areas. Enrichment factor values (EF) showed that S, Cr and Cu were highly enriched in the coal mining areas. Compared to reference area, mining regions had also higher concentrations of extractable organic matter (EOM) related to nonpolar and polar compounds. Our results demonstrate that PM_2.5 fraction represents the most important health risk for residents living near open-pit mines, underscoring the need for incorporation of ambient air standards based on PM_2.5 measures in coal mining areas.

Genotoxicity in Brazilian coal miners and its associated factors

The present study aims to evaluate the potential genotoxic and associated factors among coal miners, divided by degree of exposure. Blood and buccal smears were collected from 158 workers, who actively participate in different activities in coal mining, and 48 individuals living in the same city but do not have participation in coal mining activities (control group). The workers were divided into three different groups, according to the level of contact with coal extraction. A questionnaire intended to identify factors associated with DNA damage was performed in participants. The results regarding oral mucosa micronucleus test showed a significant difference ( p < 0.001) of the worker groups 1 and 2 in relation to the control group, where the group 1 has a higher degree of exposure to coal than group 2. For the lymphocyte micronucleus test and comet assay, there was no significant difference between the exposed groups and control group. There is an association between the outcome and the fact of living in the municipality of the mining company and the exposure to radiation in the last 12 months. Besides, the multivariate analysis showed an association of the tail moment with radiation exposure in the last 12 months. Thus, the findings of this study reveal genotoxicity in oral mucosa cells of workers exposed to coal and that workers with higher degree of contact with coal have a more pronounced response.

[Spirometry in a population of coal miners in Paipa, Colombia]

INTRODUCTION

Respiratory diseases resulting from exposure to particulate matter such as in coal mining remains a research challenge in this country and a public health issue. Spirometry is a basic test of fundamental respiratory function for the diagnosis and monitoring of these types of chronic lung diseases.

OBJECTIVE

To determine spirometric values in the coal mining municipality of Paipa and their association with age and occupational exposure times.

MATERIALS AND METHODS

We conducted a descriptive cross-sectional study. The occupational respiratory disease questionnaire of the American Thoracic Society (ATS) was completed while spirometric measurements were performed and interpreted in accordance with international recommendations for conducting the test.

RESULTS

The sample consisted of 226 coal mining workers of the municipality of Paipa. Twenty-eight subjects (12.3%) of the sample showed patterns of obstructive and restrictive respiratory disease with mild degrees of severity. Eighty subjects (35%) showed a decrease in the forced vital capacity ratio/expiratory volume in one second (FVC/FEV1). A statistically significant association between age range (p=0.002) and years of mining work (p=0.34) with the development of restrictive and obstructive disorders was found. Also, there was a statistically significant association between age range (p<0.01) and years of mining work (p<0.01) with various degrees of severity of the spirometric pattern.

CONCLUSIONS

Spirometry is a useful test for detecting the presence of respiratory disorders in the population of coal miners. The time of exposure was significantly associated with the respiratory disease exhibited by these miners.

Combinations of genotoxic tests for the evaluation of group 1 IARC carcinogens

Many of the known human carcinogens are potent genotoxins that are efficiently detected as carcinogens in human populations but certain types of compounds such as immunosuppressants, sex hormones, etc. act via non-genotoxic mechanism. The absence of genotoxicity and the diversity of modes of action of non-genotoxic carcinogens make predicting their carcinogenic potential extremely challenging. There is evidence that combinations of different short-term tests provide a better and efficient prediction of human genotoxic and non-genotoxic carcinogens. The purpose of this study is to summarize the in vivo and in vitro comet assay (CMT) results of group 1 carcinogens selected from the International Agency for Research on Cancer and to discuss the utility of the comet assay along with other genotoxic assays such as Ames, in vivo micronucleus (MN), and in vivo chromosomal aberration (CA) test. Of the 62 agents for which valid genotoxic data were available, 38 of 61 (62.3%) were Ames test positive, 42 of 60 (70%) were in vivo MN test positive and 36 of 45 (80%) were positive for the in vivo CA test. Higher sensitivity was seen in in vivo CMT (90%) and in vitro CMT (86.9%) assay. Combination of two tests has greater sensitivity than individual tests: in vivo MN + in vivo CA (88.6%); in vivo MN + in vivo CMT (92.5%); and in vivo MN + in vitro CMT (95.6%). Combinations of in vivo or in vitro CMT with other tests provided better sensitivity. In vivo CMT in combination with in vivo CA provided the highest sensitivity (96.7%).

Genotoxicity in adult residents in mineral coal region-a cross-sectional study

The present study assessed the DNA damage in environmentally exposed volunteers living in seven municipalities in an industrial coal region, through the use of the comet assay with blood cells and the micronucleus test with buccal cells. Blood and buccal smears were collected from 320 male volunteers living in seven cities inserted in a coal region. They were ages of 18 and 50 years and also completed a questionnaire intended to identify factors associated with DNA damage through a Poisson regression analysis. The comet assay detected significant differences in DNA damage in volunteers from different municipalities, and neighboring cities (Pedras Altas, Aceguá, and Hulha Negra) had a higher level of DNA damage in relation to control city. Some of the risk factors associated with identified DNA lesions included residence time and life habits. On the other hand, the micronucleus test did not identify differences between the cities studied, but the regression analysis identified risk factors such as age and life habits (consumption of mate tea and low carbohydrates diet). We conclude that there are differences in the DNA damage of volunteers from different cities of the carboniferous region, but the presence of micronuclei in the oral mucosa does not differ between the same cities. Furthermore, we alert that some related factors may increase the risk of genotoxicity, such as residence location and time, and living and food habits. Finally, we suggest the need for continuous biomonitoring of the population, as well as for investing in health promotion in these vulnerable populations.

Cytotoxic, genotoxic and mutagenic evaluation of surface waters from a coal exploration region

Coal mining generates a considerable amount of waste, which is disposed of in piles or dams near mining sites. As a result, leachates may reach rivers and streams, promoting the wide dispersion of contaminants in solution and as particulate matter. The present study evaluated the cytotoxic, genotoxic, and mutagenic action of surface waters collected around a thermoelectric power plant and the largest mining area in Brazil (Candiota). Four sites in Candiota stream were selected, and samples were collected in winter and summer. Water samples were analyzed using the comet and CBMN assays in V79 and HepG2 cells. Furthermore, genotoxicity of water samples was evaluated in vivo using the SMART in Drosophila melanogaster. In addition, polycyclic aromatic hydrocarbons and inorganic elements were quantified. The results indicate that water samples exhibited no genotoxic and mutagenic activities, whether in vitro or in vivo. On the other hand, surface water samples collected in sites near the power plant in both summer and winter inhibited cell proliferation and induced increased frequencies of V79 cell death, apoptosis, and necrosis. The cytotoxicity observed may be associated with the presence of higher concentration of inorganic elements, especially aluminum, silicon, sulfur, titanium and zinc at sites 1 and 2 in the stream, as well as with the complex mixture present in the coal, in both seasons. Therefore, the results obtained point to the toxicity potential of water samples with the influence of coal mining and combustion processes and the possible adverse effects on the health of exposed organisms.

Absence of genotoxic effects of the chalcone (E)-1-(2-hydroxyphenyl)-3-(4-methylphenyl)-prop-2-en-1-one) and its potential chemoprevention against DNA damage using in vitro and in vivo assays

The chalcone (E)-1-(2-hydroxyphenyl)-3-(4-methylphenyl)-prop-2-en-1-one), or 2HMC, displays antileishmanial, antimalarial, and antioxidant activities. The aim of this study was to investigate the cytotoxic, genotoxic, mutagenic, and protective effects of 2HMC using the Ames mutagenicity test, the mouse bone marrow micronucleus test, and the comet assay in mice. In the assessment using the Ames test, 2HMC did not increase the number of His⁺ revertants in Salmonella typhimurium strains, demonstrating lack of mutagenicity. 2HMC showed no significant increase in micronucleated polychromatic erythrocyte frequency (MNPCE) in the micronucleus test, or in DNA strand breaks using the comet assay, evidencing absence of genotoxicity. Regarding cytotoxicity, 2HMC exhibited moderate cytotoxicity in mouse bone marrow cells by micronucleus test. 2HMC showed antimutagenic action in co-administration with the positive controls, sodium azide (SA) and 4-nitroquinoline-1-oxide (4NQO), in the Ames test. Co-administered and mainly pre-administered with cyclophosphamide (CPA), 2HMC caused a decrease in the frequency of MNPCE using the micronucleus test and in DNA strand breaks using the comet assay. Thus, 2HMC exhibited antimutagenic and antigenotoxic effects, displaying a DNA-protective effect against CPA, SA, and 4NQO carcinogens. In conclusion, 2HMC presented antimutagenic, antigenotoxic and moderate cytotoxic effects; therefore it is a promising molecule for cancer prevention.

DNA damage induced by coal dust, fly and bottom ash from coal combustion evaluated using the micronucleus test and comet assay in vitro

Coal mining and combustion generating huge amounts of bottom and fly ash are major causes of environmental pollution and health hazards due to the release of polycyclic aromatic hydrocarbons (PAH) and heavy metals. The Candiota coalfield in Rio Grande do Sul, is one of the largest open-cast coal mines in Brazil. The aim of this study was to evaluate genotoxic and mutagenic effects of coal, bottom ash and fly ash samples from Candiota with the comet assay (alkaline and modified version) and micronucleus test using the lung fibroblast cell line (V79). Qualitative and quantitative analysis of PAH and inorganic elements was carried out by High Performance Liquid Chromatography (HPLC) and by Particle-Induced X-ray Emission (PIXE) techniques respectively. The samples demonstrated genotoxic and mutagenic effects. The comet assay modified using DNA-glicosilase formamidopirimidina (FPG) endonuclease showed damage related to oxidative stress mechanisms. The amount of PAHs was higher in fly ash followed by pulverized coal. The amount of inorganic elements was highest in fly ash, followed by bottom ash. It is concluded that the samples induce DNA damage by mechanisms that include oxidative stress, due to their complex composition, and that protective measures have to be taken regarding occupational and environmental hazards.

Cytotoxicity and genotoxicity induced by coal and coal fly ash particles samples in V79 cells

Exposure to coal and coal ashes can cause harmful effects in in vitro and in vivo systems, mainly by the induction of oxidative damage. The aim of this work was to assess cytotoxic and genotoxic effects using the V79 cell line treated with coal and coal fly ash particles derived from a coal power plant located in Santa Catarina, Brazil. Two coal samples (COAL11 and COAL16) and two coal fly ash samples (CFA11 and CFA16) were included in this study. COAL16 was co-firing with a mixture of fuel oil and diesel oil. The comet assay data showed that exposure of V79 cells to coal and coal fly ash particles induced primary DNA lesions. Application of lesion-specific endonucleases (FPG and ENDO III) demonstrated increased DNA effects indicating the presence of high amounts of oxidative DNA lesions. The cytokinesis-block micronucleus cytome assay analysis showed that exposure of V79 cells to high concentrations of coal and coal fly ash particles induced cytotoxic effects (apoptosis and necrosis) and chromosomal instability (nucleoplasmic bridges, nuclear buds, and micronucleus (MN) formation). These results may be associated with compounds contained in the surface of the particles as hazardous elements, ultrafine/nanoparticles, and polycyclic aromatic hydrocarbons (PAHs) which were detected in the samples. Graphical abstract ᅟ.

Chemical and toxicological effects of medicinal Baccharis trimera extract from coal burning area

The entire process of power generation, extraction, processing and use of coal strongly impact water resources, soil, air quality and biota leads to changes in the fauna and flora. Pollutants generated by coal burning have been contaminating plants that grow in area impacted by airborne pollution with high metal contents. Baccharis trimera is popularly consumed as tea, and is widely developed in Candiota (Brazil), one of the most important coal burning regions of the Brazil. This study aims to investigate the phytochemical profile, in vivo genotoxic and mutagenic potential of extracts of B. trimera collected from an exposed region to pollutants generated by coal burning (Candiota City) and other unexposed region (Bagé City), using the Comet assay and micronucleus test in mice and the Salmonella/microsome short-term assay. The HPLC analyses indicated higher levels of flavonoids and phenolic acids for B. trimera aqueous extract from Bagé and absence of polycyclic aromatic hydrocarbons for both extracts. The presence of toxic elements such as cobalt, nickel and manganese was statistically superior in the extract from Candiota. For the Comet assay and micronucleus test, the mice were treated with Candiota and Bagé B. trimera aqueous extracts (500-2000 mg/kg). Significant genotoxicity was observed at higher doses treated with B. trimera aqueous extract from Candiota in liver and peripheral blood cells. Micronuclei were not observed but the results of the Salmonella/microsome short-term assay showed a significant increase in TA98 revertants for B. trimera aqueous extract from Candiota. The extract of B. trimera from Candiota bioacumulated higher levels of trace elements which were associated with the genotoxic effects detected in liver and peripheral blood cells.

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

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