Cytogenetic damage in workers from a coal-fired power plant

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.

A comprehensive review of toxicity of coal fly ash and its leachate in the ecosystem

Coal fly ash (CFA), a byproduct of coal combustion, is a hazardous industrial solid waste. Its excessive global production, coupled with improper disposal practices, insufficient utilization and limited awareness of its inherent hazards, poses a significant threat to both ecological environment and human health. Based on the physicochemical properties of CFA and its leachates, we elucidate the forms of CFA and potential pathways for its entry into the human body, as well as the leaching behavior, maximum tolerance and biological half-life of toxic elements present in CFA. Furthermore, we provide an overview of current strategies and methods for mitigating the leaching of these harmful elements from CFA. Moreover, we systemically summarize toxic effect of CFA on organisms across various tiers of complexity, analyze epidemiological findings concerning the human health implications resulting from CFA exposure, and delve into the biotoxicological mechanisms of CFA and its leachates at cellular and molecular levels. This review aims to enhance understanding of the potential toxicity of CFA, thereby promoting increased public awareness regarding the disposal and management of this industrial waste.

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.

Cytotoxic effects of wildfire ashes: In-vitro responses of skin cells

Wildfires are a complex environmental problem worldwide. The ashes produced during the fire bear metals and PAHs with high toxicity and environmental persistence. These are mobilized into downhill waterbodies, where they can impair water quality and human health. In this context, the present study aimed at assessing the toxicity of mimicked wildfire runoff to human skin cells, providing a first view on the human health hazardous potential of such matrices. Human keratinocytes (HaCaT) were exposed to aqueous extracts of ashes (AEA) prepared from ash deposited in the soil after wildfires burned a pine or a eucalypt forest stand. Cytotoxicity (MTT assay) and changes in cell cycle dynamics (flow cytometry) were assessed. Cell viability decreased with increasing concentrations of AEA, regardless of the ash source, the extracts preparation method (filtered or unfiltered to address the dissolved or the total fractions of contaminants, respectively) or the exposure period (24 and 48 h). The cells growth was also negatively affected by the tested AEA matrices, as evidenced by a deceleration of the progress through the cell cycle, namely from phase G0/G1 to G2. The cytotoxicity of AEA could be related to particulate and dissolved metal content, but the particles themselves may directly affect the cell membrane. Eucalypt ash was apparently more cytotoxic than pine ash due to differential ash metal burden and mobility to the water phase. The deceleration of the cell cycle can be explained by the attempt of cells to repair metal-induced DNA damage, while if this checkpoint and repair pathways are not well coordinated by metal interference, genomic instability may occur. Globally, our results trigger public health concerns since the burnt areas frequently stand in slopes of watershed that serve as recreation sites and sources of drinking water, thus promoting human exposure to wildfire-driven contamination.

Coal beneficiation technology to reduce hazardous heavy metals in fly ash

Fly ash emitted from the coal-fired power plant is the major contributor of the outdoor airborne particulate matters (PMs). Coal beneficiation, an industrial process to improve the quality of raw coal by removing ash-bearing components, can be a cost-effective sustainable and clean technology to reduce the emission of hazardous trace metals. As the removal efficiency of mineral matters and heavy metals within the coal is depend highly on the raw coal and the employed beneficiation process, a wide range of case studies at laboratory- and industrial-scale, published in the last 20 years, are reviewed in this study. Our review indicates that the coal beneficiation processes can effectively reduce content of heavy metals of fly ash, encouraging the use of clean coal to reduce pollutants emission.

Nail Samples of Children Living near Coal Ash Storage Facilities Suggest Fly Ash Exposure and Elevated Concentrations of Metal(loid)s

Children who live near coal-fired power plants are exposed to coal fly ash, which is stored in landfills and surface impoundments near residential communities. Fly ash has the potential to be released as fugitive dust. Using data collected from 263 children living within 10 miles of coal ash storage facilities in Jefferson and Bullitt Counties, Kentucky, USA, we quantified the elements found in nail samples. Furthermore, using principal component analysis (PCA), we investigated whether metal(loid)s that are predominately found in fly ash loaded together to indicate potential exposure to fly ash. Concentrations of several neurotoxic metal(loid)s, such as chromium, manganese, and zinc, were higher than concentrations reported in other studies of both healthy and environmentally exposed children. From PCA, it was determined that iron, aluminum, and silicon in fly ash were found to load together in the nails of children living near coal ash storage facilities. These metal(loid)s were also highly correlated with each other. Last, results of geospatial analyses partially validated our hypothesis that children's proximity to power plants was associated with elevated levels of concentrations of fly ash metal(loid)s in nails. Taken together, nail samples may be a powerful tool in detecting exposure to fly ash.

A review on fly ash from coal-fired power plants: chemical composition, regulations, and health evidence

Throughout the world, coal is responsible for generating approximately 38% of power. Coal ash, a waste product, generated from the combustion of coal, consists of fly ash, bottom ash, boiler slag, and flue gas desulfurization material. Fly ash, which is the main component of coal ash, is composed of spherical particulate matter with diameters that range from 0.1 μm to >100 μm. Fly ash is predominately composed of silica, aluminum, iron, calcium, and oxygen, but the particles may also contain heavy metals such as arsenic and lead at trace levels. Most nations throughout the world do not consider fly ash a hazardous waste and therefore regulations on its disposal and storage are lacking. Fly ash that is not beneficially reused in products such as concrete is stored in landfills and surface impoundments. Fugitive dust emissions and leaching of metals into groundwater from landfills and surface impoundments may put people at risk for exposure. There are limited epidemiological studies regarding the health effects of fly ash exposure. In this article, the authors provide an overview of fly ash, its chemical composition, the regulations from nations generating the greatest amount of fly ash, and epidemiological evidence regarding the health impacts associated with exposure to fly ash.

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.

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.

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.

Recruitment strategies and challenges: Lessons learned from a coal ash and children's health study

The purpose of this paper is to describe the approaches and recruitment strategies of a study focused on the impact of coal fly ash on neurobehavioral performance among children living in proximity to coal-burning power plants. Challenges encountered with each recruitment approach are highlighted as well as solutions used to overcome those challenges and ultimately enroll children and one of their parents or guardians. To ensure participants were distributed throughout the study area, geographical information systems were used to guide recruitment and achieve the target sample size (N = 300). Several approaches were employed to recruit the number of needed participants, including "shoe leather" or door-to-door recruitment, placement of flyers and brochures in public spaces, mailings to targeted addresses, media announcements, and local government outreach. Since September 2015, 265 participants have been enrolled in the study using a combination of the described recruitment approaches. Even with a well-designed plan, it is important to re-examine strategies at every step to maximize recruitment efforts. Researcher flexibility in adapting to new strategies is vital in facilitating recruitment efforts, and the recruitment of participants in the study remains a dynamic and evolving process.

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.

Genetic effects in Helix aspersa near a coal plant revealed by the micronucleus test

Coal plants can be a major source of mutagenic pollutants. In this study we used the common land snail Helix aspersa, to detect the mutagenic effect of pollution from a coal plant in central Italy applying the micronucleus test (MN) on snail's haemocytes and evaluating trace elements concentration (As Cd, Pb, Hg, and Zn) in soil and snails. Snails from a biological farm were exposed for 13 days in five locations at different distances from the plant. Wild snails collected in the same locations were also analysed. MN frequency in exposed snails was significantly higher in four locations within 10 km from to the plant, with respect to the control and the farthest location. Comparing the MN frequency between farmed and wild snails, a significantly higher frequency emerged for the exposed snails in all locations except the farthest, likely indicating adaptation or selection of the wild organisms due to chronic exposure to pollutants. In natural snails significantly higher MN frequencies with near the plant emerged as well. Trace elements analysis showed significant correlations between MN frequencies and both Zn and As concentrations in soil, for both exposed and wild snails, and Zn and Pb concentrations in exposed snails. Our results were consistent with those previously obtained when evaluating primary DNA damage in natural snails from the same area and show that the snails near the plant were affected by a permanent cytogenetic damage. Moreover, they confirm the suitability of snails for biomonitoring the presence of pollutants with mutagenic effect.

Peak exposures to main components of ash and gaseous diesel exhausts in closed and open ash loading stations at biomass-fuelled power plants

Fly and bottom ashes are collected at power plants to reduce the environmental effects of energy production. However, handling the ashes causes health problems for operators, maintenance workers and truck drivers at the power plants. Hence, we evaluated ash loaders' peak inhalation exposures to the chemical components of ash and diesel exhausts in open and closed ash loading stations at biomass-fuelled combined heat and power plants. We also carried out chemical and morphological analyses of the ashes to evaluate their health hazard potential in order to find practical technical measures to reduce workers' exposure. On the basis of X-ray diffraction analyses, the main respirable crystalline ash compounds were SiO₂, CaSO₄, CaO, Ca₂Al₂SiO₇, NaCl and Ca₃Al₂O₆ in the fly ashes and SiO₂, KAlSi₃O₈, NaAlSi₃O₈ and Ca₂Al₂SiO₇ in the bottom ashes. The short-term exposure levels of respirable crystalline silica, inhalable inorganic dust, Cr, Mn, Ni and nitric oxide exceeded their Finnish eight hours occupational exposure limit values in the closed ash loading station. According to our observations, more attention should be paid to the ash-moistening process, the use of tank trucks instead of open cassette flatbed trucks, and the sealing of the loading line from the silo to the truck which would prevent spreading the ash into the air. The idling time of diesel trucks should also be limited, and ash loading stations should be equipped with exhaust gas ventilators. If working conditions make it impossible to keep to the OEL values, workers must use respirators and protect their eyes and skin.

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.

Application of the micronucleus test and comet assay in Trachemys callirostris erythrocytes as a model for in situ genotoxic monitoring

Trachemys callirostris is a turtle species endemic to northern South America. In northern Colombia it occurs in the middle and lower Magdalena River drainage and its principal tributaries (lower Cauca and San Jorge rivers) and in other minor drainages such as the lower Sinú River. In recent years, industrial, agricultural, and mining activities have altered natural habitats in Colombia where this species occurs, and many of the pollutants released there are known to induce genetic alterations in wildlife species. The micronucleus test and comet assay are two of the most widely used methods to characterize DNA damage induced by physical and chemical agents in wildlife species, but have not been employed previously for genotoxic evaluations in T. callirostris. The goal of this study was to optimize these genotoxic biomarkers for T. callirostris erythrocytes in order to establish levels of DNA damage in this species and thereby evaluate its potential as a sentinel species for monitoring genotoxic effects in freshwater environments in northern Colombia. Both genotoxic techniques were applied on peripheral blood erythrocytes from 20 captive-reared T. callirostris individuals as a negative control, as well as from samples obtained from 49 individuals collected in Magangué (Magdalena River drainage) and 24 individuals collected in Lorica (Sinú River drainage) in northern Colombia. Negative control individuals exhibited a baseline frequency of micronuclei of 0.78±0.58 and baseline values for comet tail length and tail moment of 3.34±0.24µm and 10.70±5.5, respectively. In contrast, samples from both field sites exhibited significantly greater evidence of genotoxic effects for both tests. The mean MN frequencies in the samples from Magangué and Lorica were 8.04±7.08 and 12.19±12.94, respectively. The mean tail length for samples from Magangué and Lorica were 5.78±3.18 and 15.46±7.39, respectively. Finally, the mean tail moment for samples from Magangué and Lorica were 23.59±18.22 and 297.94±242.18, respectively. The frequency of micronuclei in the samples was positively related to comet tail length and tail moment. Thus, this study showed that both genotoxicity biomarkers may be applied to T. callirostris erythrocytes as a sentinel organism for assessing the effects of environmental pollutants in freshwater ecosystems in northern South America.

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.

Community views about the health and exposure of children living near a coal ash storage site

Coal ash, a waste product generated from burning coal, is composed of small particles comprised of highly toxic elements. Coal ash particles contain heavy metals such as arsenic, lead, and mercury, as well as polyaromatic hydrocarbons and radioactive elements. Most coal ash is stored in landfills and ponds, often located in close proximity to low income communities. Currently, there are no federal regulations governing the storage and transport of coal ash; however the Environmental Protection Agency proposed a coal ash rule in 2010, which could designate coal ash as a hazardous waste. This is the first article to assess community impact from coal ash storage, by exploring parents' perceptions of their children's health and its relationship to chronic exposure to coal ash. This was a community-based study involving four neighborhoods adjacent to a large coal ash storage facility. Focus groups were conducted with community members and the transcripts were analyzed to identify themes regarding children's health, children's exposure to coal ash, and behaviors done to protect children from exposure. The majority of parents (85 %) reported that their children suffered from health conditions; specifically respiratory and emotional and behavioral disorders. Parents highlighted ways in which their children were exposed to coal ash, although many felt they were constantly exposed just by living in the area. Parents felt strongly that exposure to coal ash from the landfill is affecting the health and well-being of their children. Some parents attempted protective behaviors, but most parents felt helpless in reducing children's exposure.

Evaluation of the genotoxic potential of soil contaminated with mineral coal tailings on snail Helix aspersa

Coal remains an important source of energy, although the fuel is a greater environmental pollutant. Coal is a mixture of several chemicals, especially inorganic elements and polycyclic aromatic hydrocarbons (PAH). Many of these compounds have mutagenic and carcinogenic effects on organisms exposed to this mineral. In the town of Charqueadas (Brazil), the tailings from mining were used for landfill in the lower areas of the town, and the consequence is the formation of large deposits of this material. The purpose of this study was to evaluate the genotoxic potential of soil samples contaminated by coal waste in different sites at Charqueadas, using the land snail Helix aspersa as a biomonitor organism. Thirty terrestrial snails were exposed to different treatments: 20 were exposed to the soil from two different sites in Charqueadas (site 1 and 2; 10 in each group) and 10 non-exposed (control group). Hemolymph cells were collected after 24h, 5days and 7days of exposure and comet assay, micronucleus test, oxidative stress tests were performed. Furthermore, this study quantified the inorganic elements present in soil samples by the PIXE technique and polycyclic aromatic hydrocarbons (PAH) by HPLC. This evaluation shows that, in general, soils from sites in Charqueadas, demonstrated a genotoxic effect associated with increased oxidative stress, inorganic and PAH content. These results demonstrate that the coal pyrite tailings from Charqueadas are potentially genotoxic and that H. aspersa is confirmed to be a sensitive instrument for risk assessment of environmental pollution.

Exposure-Reducing Behaviors Among Residents Living Near a Coal Ash Storage Site

Coal ash, a waste product generated from burning coal for energy, is composed of highly respirable particles containing heavy metals, radioactive elements, and polycylic aromatic hydrocarbons. Coal ash is stored in landfills and surface impoundments frequently located near neighborhoods. Fugitive dust from the storage sites exposes neighborhoods, affecting the health and welfare of residents. The research questions of interest were (1) are community members concerned about coal ash exposure from the storage site; (2) what, if any, behaviors do community members engage in to reduce exposure; and (3) do exposure reducing behaviors differ by level of concern about coal ash. A community-based mixed-methods approach was used. Focus groups (n = 26) were conducted in 2012, and a cross-sectional survey was administered in 2013 (n = 231). The majority of survey respondents (62%) worried "a lot" about being exposed to coal ash; however, most did not engage in exposure-reducing behaviors, such as wearing protective equipment when doing chores. Compared with respondents who worry "some, very little, or none," or responded "I don't know," respondents who worried "a lot" about being exposed to coal ash did more exposure-reducing behaviors outdoors (p < .001) and indoors (p = .01). For people living near environmental hazards, reducing exposure is a priority. Although challenging because of the chronic nature of exposure, some behaviors can be useful in reducing exposure, such as wearing a particle-specific respirator when mowing the lawn. Communities at risk for chronic exposure to environmental toxins could benefit from education about exposure-reducing behaviors.

Genetic damage in coal miners evaluated by buccal micronucleus cytome assay

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

Tools used to estimate soil quality in coal combustion waste areas

Soil is a highly complex environmental compartment that has suffered with the contamination of substances of various origins. Among the main activities that affect soil quality are power generation activities that use fossil fuels, such as mineral coal. Environmental protection agencies encourage scientific investigations using tools described in legal devices or standard protocols to evaluate the potential of coal as a pollutant, especially in places that have large reserves of this mineral like the state of Rio Grande do Sul. The aim of this study was to characterize the leached extracts of different soils from an area influenced by coal waste, to classify them according to the guideline values for groundwater described in CONAMA's n. 420/2009, and to estimate the effects of the leachates ingestion in DNA mutation rates. The volume of soil needed to induce a 100% increase in the spontaneous mutation rate varied between 129.3 and 1544.1 mg of soil among the soils studied. Metals such as Mn, Pb, Cd and Ni surpassed the investigation limits for groundwater at least in one soil sample. The results showed that there can be transfer of soil contaminants to groundwater and soil intake in the area could contribute to the increased mutagenic risk.

Occupational exposure to solid chemical agents in biomass-fired power plants and associated health effects

Occupational exposure to aluminium, arsenic, lead, cadmium, and manganese can increase the risk of numerous neurophysiological changes in workers, and may lead to conditions resembling Parkinson's and Alzheimer's disease. However, although the health hazard aspect of these agents has been examined, biomass-fired power plant workers' exposure to them remains a neglected issue. The purpose of this study was to measure maintenance and ash removal workers' multiple exposures to inhalable dust, metals, and crystalline silica during their work tasks in biomass-fired power plants. Maintenance and ash removal workers were exposed to high inhalable dust concentrations inside biomass-fired boilers. The median air inhalable dust concentration in workers' breathing zones were 33 mg m(-3) and 120 mg m(-3) in ash removal and maintenance tasks, respectively. The median concentration of manganese (0.31 mg m(-3)) exceeded the occupational exposure limit in worker's breathing zone samples in maintenance tasks. The most evident exposure-associated health risk from multiple exposures to metals was that of cancer, followed by central nervous system disorders, lower respiratory tract irritation, and finally upper respiratory tract irritation. To avoid the above mentioned health effects, powered air respirators with ABEK+P3 cartridges and carbon monoxide gas detectors are recommended as the minimum requirement for these work tasks. A compressed air breathing apparatus is the best form of protection for the most demanding work phases inside boilers in biomass-fired power plants.

Baccharis trimera (Less.) DC as genotoxicity indicator of exposure to coal and emissions from a thermal power plant

During coal combustion, hazardous elements are discharged that impair environmental quality. Plant cover is the first available surface for the atmospheric pollutants in terrestrial ecosystems. The aim of this study was to evaluate genotoxicity in the aqueous extract of the native plant, Baccharis trimera, exposed to coal and emissions from a thermal power plant (coal-fired power plant in Candiota, Brazil), correlating seasonality, wind tunnel predominance, and presence of inorganic elements. The presence of inorganic elements in the aerial parts of B. trimera was analyzed by particle-induced X-ray emission (PIXE) spectrometry, and genotoxicity was evaluated by ex vivo comet assay. The genotoxic effects of aqueous extracts of B. trimera from four sites located in the area around power plant were analyzed by comet assay in peripheral human lymphocytes. Winter samples showed greater levels of metals than summer samples. Genotoxicity was detected in B. trimera extracts collected from the region exposed to extraction and burning coal. Extracts from the site impacted by the dominant wind induced more damage to DNA than those from other sites. Based on our data, we can suggest that in winter the inorganic elements from extraction and burning of coal and carried through the wind tunnel were responsible for the genotoxicity observed in aqueous extract of B. trimera.

Occupational exposure to gases, polycyclic aromatic hydrocarbons and volatile organic compounds in biomass-fired power plants

The combustion of fuels produces air pollutants in the form of gases, organic compounds, and particulate matter. However, although the environmental aspect of these agents has been examined, workers' exposure to them is still a neglected issue. The purpose of this study was to measure maintenance and ash removal workers' multiple exposures to gases, volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) during their work tasks in biomass-fired power plants. Our hygienic measurements revealed that carbon monoxide, nitric oxide, ammonia and sulfur dioxide were the most common gases that the workers were exposed to during their tasks. Their average concentrations were 0.45 ppm, 0.06 ppm, 0.11 ppm and 0.42 ppm, respectively. Phenanthrene and naphthalene were the most prominent PAHs. At the same sampling points, the most commonly found VOCs were aromatic and aliphatic hydrocarbons and turpentines. The calculated total PAH concentrations were less than 7% of benzo[a]pyrene's eight-hour occupational exposure limit, and the total VOC concentrations were below the Finnish reference value for the normal industrial level in all measured work tasks. The most evident health effect caused by multiple exposures to gases was upper respiratory track irritation, followed by the disruption of oxygen transport, and finally central nervous system disorders. We recommend powered air respirators with ABEK+P3 cartridges and carbon monoxide gas detectors as the minimum requirement for those working inside biomass-fired power plant boilers, and compressed air breathing apparatus as the best form of protection.

Evaluation of genetic damage in open-cast coal mine workers using the buccal micronucleus cytome assay

Coal is the largest fossil fuel source used for the generation of energy. However, coal extraction and its use constitute important pollution factors; thus, risk characterization and estimation are extremely important for the safety of coal workers and the environment. Candiota is located to the southeast of the state of Rio Grande do Sul and has the largest coal reserves in Brazil, and the largest thermal power complex in the state. In the open-cast mines, the coal miners are constantly exposed to coal dust. The human buccal micronucleus cytome (BMCyt) assay has been used widely to investigate biomarkers for DNA damage, cell death, and basal cell frequency in buccal cells. The aim of this study was to assess whether prolonged exposure to coal dust could lead to an increase in genomic instability, cell death, and frequency of basal cells using the BMCyt assay. In the analysis of epithelial cells, the exposed group (n = 41) presented with a significantly higher frequency of basal cells, micronuclei in basal and differentiated cells, and binucleated cells compared to the non-exposed group (n = 29). The exposed group showed a significantly lower frequency of condensed chromatin cells than the non-exposed group. However, we found no correlation between DNA damage and metal concentration in the blood of mine workers. DNA damage observed in the mine workers may be a consequence of oxidative damage resulting from exposure to coal residue mixtures. In addition, our findings confirm that the BMCyt assay can be used to identify occupational risk.

Characterization of coal fly ash nanoparticles and induced oxidative DNA damage in human peripheral blood mononuclear cells

The nano-sized particles present in coal fly ash (CFA) were characterized through the X-ray diffraction (XRD), transmission and scanning electron microscopy (TEM, SEM), atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR) analyses. The XRD data revealed the average crystallite size of the CFA nanoparticles (CFA-NPs) as 14 nm. TEM and SEM imaging demonstrated predominantly spherical and some polymorphic structures in the size range of 11 to 25 nm. The amount of heavy metal associated with CFA particles (μg/g) were determined as Fe (34160.0±1.38), Ni (150.8±0.78), Cu (99.3±0.56) and Cr (64.0±0.86). However, the bioavailability of heavy metals in terms of percent release was in the order as Cr>Ni>Cu>Fe in CFA-dimethyl sulfoxide (DMSO) extract. The comet and cytokinesis blocked micronucleus (CBMN) assays revealed substantial genomic DNA damage in peripheral blood mononuclear (PBMN) cells treated with CFA-NPs in Aq and DMSO extracts. About 1.8 and 3.6 strand breaks per unit of DNA were estimated through alkaline unwinding assay at 1:100 DNA nucleotide/CFA ppm ratios with the Aq and DMSO extracts, respectively. The DNA and mitochondrial damage was invariably greater with CFA-DMSO extract vis-à-vis -Aq extract. Generation of superoxide anions (O(2)•(-)) and intracellular reactive oxygen species (ROS) through metal redox-cycling, alteration in mitochondrial potential and 8-oxodG production elucidated CFA-NPs induced oxidative stress as a plausible mechanism for CFA-induced genotoxicity.

Genotoxic effects in blood cells of Mus musculus and Iguana iguana living near coal mining areas in Colombia

Coal is a mixture of chemicals with the capacity of promoting biochemical changes that may lead to DNA damage. In this study, the comet assay in peripheral blood cells, and the micronucleus test in blood smears were used to evaluate potential genotoxic effects derived from exposure to coal mining activities on wild populations of Mus musculus and Iguana iguana. Four locations from Colombia were evaluated: La Loma and La Jagua de Ibirico, two municipalities located near coal mining fields at the Department of Cesar; and Valledupar and Arjona, cities used as reference sites, both localized at least 100 and 200km far from the mines, respectively. Compared to Valledupar and Arjona, animals collected in close proximity to coal mining areas showed highest percentages of DNA damage for both species, evidencing that living around coal mining fields may result in an increase of DNA lesions in blood cells of rodents and reptiles. The results for micronucleus test were conflicting. Mice from Arjona had greater number of cells with micronucleus than those from the other studied locations, probably as a result of infection found by blood parasites. In summary, it was demonstrated that animals living around coal mining areas have a greater chance of having DNA damage, as measured by the comet assay, than those from sites far from the coal dust source.

Combined analysis of chromosomal aberrations and glutathione S-transferase M1 and T1 polymorphisms in pathologists occupationally exposed to formaldehyde

The formaldehyde (FA) genotoxic potential in occupationally exposed individuals is conflicting. A relevant indoor-air FA pollution was found in hospitals and scientific institutions where FA is used as a bactericide and tissue preservative. In the present study, we evaluated the frequency of chromosomal aberrations (CAs) in peripheral blood lymphocytes from workers in pathology wards who have been exposed to FA, compared with a group of unexposed subjects. The subjects were also analyzed for the GSTM1 and GSTT1 metabolic gene polymorphisms. The exposed subjects showed a significant increase in the frequency of CA per cell and in the percentage of cells with aberrations compared to control subjects. The different GST genotypes did not affect the level of cytogenetic damage since CA frequencies were not statistically different between the GST "null" genotypes and the GST "positives". The generalized linear models showed that the number of CAs and cells with CAs increased with age, but, independent of age, it was significantly higher in the experimental rather than in the control group. Cubic-spline regression confirmed the linear relationship between CAs and age, but it provided evidence for a non-linear relationship between CAs and the number of years of FA exposure. Similar results were observed when the model included the number of cells with CAs as dependent variables. Our results demonstrate that air FA induces CAs even consequently to low levels of daily exposure, indicating an increased risk of genetic damage for workers exposed to this air pollutant.

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

Coal mining is one of the most important causes of environmental pollution, as large quantities of coal dust particles are emitted. Colombia-South America has large natural coal reserves and "El Cerrejón" is the world's largest open-cast mine located in the northern department of Guajira. The aim of the present study was to evaluate genotoxic effects in a population exposed to coal residues from the open-cast mine "El Cerrejón". 100 exposed workers and 100 non-exposed control individuals were included in this study. The exposed group was divided according to different mining area activities: (i). Transport of extracted coal, (ii). Equipment field maintenance, (iii). Coal stripping and, (iv). Coal embarking. Blood samples were taken to investigate biomarkers of genotoxicity, specifically, primary DNA damage as damage index (DI), tail length and% of tail DNA using the Comet assay (alkaline version) and chromosome damage as micronucleus (MN) frequency in lymphocytes. Both biomarkers showed statistically significantly higher values in the exposed group compared to the non-exposed control group. No difference was observed between the exposed groups executing different mining activities. These results indicate that exposure to coal mining residues may result in an increased genotoxic exposure in coal mining workers. We did not find a correlation between age, alcohol consumption and service time with the biomarkers of genotoxicity. Our results are the first data of genotoxic effects induced by coal mining exposure in Colombia, and thus, contribute to the exploration of test batteries use for monitoring of exposed populations and may stimulate designing control, hygiene and prevention strategies for occupational health risk assessment in developing countries.

Antioxidant intervention compensates oxidative stress in blood of subjects exposed to emissions from a coal electric-power plant in South Brazil

In the process of energy generation, particulate matter (PM) emissions derived from coal combustion expose humans to serious occupational diseases, which are associated with overgeneration of reactive oxygen species (ROS). The purpose of the present study is to better understand the relations between PM exposure derived from a coal electric-power plant and the oxidative damage in subjects (n=20 each group) directly (working at the burning area) or indirectly (working at the office or living in the vicinity of the electric-power plant=group of residents) exposed to airborne contamination, before and after daily supplementation with vitamins C (500mg) and E (800mg) during six months, which were compared to non-exposed subjects (control group). Several biomarkers of oxidative stress were examined such as levels of thiobarbituric acid reactive substances (TBARS), protein carbonyls (PC), protein thiols (PT) and vitamin E in plasma, levels of reduced glutathione (GSH) in whole blood, and of activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione S-transferase (GST) in red cells. Before supplementation, TBARS and PC levels were significantly increased, levels of GSH and vitamin E were decreased, while the activities of SOD and CAT were increased in workers groups and GST were increased in all groups in compared to controls. After the antioxidant supplementation essentially all these biomarkers were normalized to control levels. The antioxidant intervention was able to confer a protective effect of vitamins C and E against the oxidative insult associated with airborne contamination derived from coal burning of an electric-power plant.

Comparative study on elemental composition and DNA damage in leaves of a weedy plant species, Cassia occidentalis, growing wild on weathered fly ash and soil

Open dumping of fly ash in fly ash basins has significant adverse environmental impacts due to its elevated trace element content. In situ biomonitoring of genotoxicity is of practical value in realistic hazard identification of fly ash. Genotoxicity of openly disposed fly ash to natural plant populations inhabiting fly ash basins has not been investigated. DNA damage, and concentrations of As, Co, Cr, Cu and Ni in the leaves of natural populations of Cassia occidentalis growing at two contrasting sites-one having weathered fly ash (fly ash basin) and the other having soil (reference site) as plant growth substrates-were assessed. The foliar concentrations of As, Ni and Cr were two to eight fold higher in plants growing on fly ash as compared to the plants growing on soil, whereas foliar concentrations of Cu and Co were similar. We report, for the first time, based upon comet assay results, higher levels of DNA damage in leaf tissues of Cassia occidentalis growing wild on fly ash basin compared to C. occidentalis growing on soil. Correlation analysis between foliar DNA damage and foliar concentrations of trace elements suggests that DNA damage may perhaps be associated with foliar concentrations of As and Ni. Our observations suggest that (1) fly ash triggers genotoxic responses in plants growing naturally on fly ash basins; and (2) plant comet assay is useful for in situ biomonitoring of genotoxicity of fly ash.