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.

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.