Micronuclei, Pesticides, and Element Mixtures in Mining Contexts: The Hormetic Effect of Selenium.

The contexts where there are mining and agriculture activities are potential sources of risk to human health due to contamination by chemical mixtures. These contexts are frequent in several Colombian regions. This study explored the potential association between the frequency of micronuclei and pesticides and elements in regions with ferronickel (Montelibano, Córdoba) and gold (Nechí, Antioquia) mining, and a closed native mercury mine (Aranzazu, Caldas), with an emphasis in the potential effect of selenium as a potential chelator. A cross-sectional study was carried out with 247 individuals. Sociodemographic, occupational, and toxicological variables were ascertained. Blood and urine samples were taken for pesticide analysis (5 organophosphates, 4 organochlorines, and 3 carbamates), 68 elements were quantified in hair, and micronuclei were quantified in lymphocytes. The mixtures of elements were grouped through principal component analysis. Prevalence ratios were estimated with robust variance Poisson regressions to explore associations. Interactions of selenium with toxic elements were explored. The highest concentrations of elements were in the active mines. The potentially most toxic chemical mixture was observed in the ferronickel mine. Pesticides were detected in a low proportion of participants (<2.5%), except paraoxon-methyl in blood (27.55%) in Montelibano and paraoxon-ethyl in blood (18.81%) in Aranzazu. The frequency of micronuclei was similar in the three mining contexts, with means between 4 to 7 (p = 0.1298). There was great heterogeneity in the exposure to pesticides and elements. The "hormetic effect" of selenium was described, in which, at low doses, it acts as a chelator in Montelibano and Aranzazu, and at high doses, it can enhance the toxic effects of other elements, maybe as in Nechí. Selenium can serve as a protective agent, but it requires adaptation to the available concentrations in each region to avoid its toxic effects.

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.

Genetic Instability among Hitnü People Living in Colombian Crude-Oil Exploitation Areas.

Oil exploitation, drilling, transportation, and processing in refineries produces a complex mixture of chemical compounds, including polycyclic aromatic hydrocarbons (PAHs), which may affect the health of populations living in the zone of influence of mining activities (PZOI). Thus, to better understand the effects of oil exploitation activities on cytogenetic endpoint frequency, we conducted a biomonitoring study in the Hitnü indigenous populations from eastern Colombia by using the cytokinesis micronucleus cytome assay (CBMN-cyt). PAH exposure was also measured by determine urine 1-hydroxypyrene (1-OHP) using HPLC. We also evaluated the relationship between DNA damage and 1-OHP levels in the oil exploitation area, as well as the modulating effects of community health factors, such as Chagas infection; nutritional status; and consumption of traditional hallucinogens, tobacco, and wine from traditional palms. The frequencies of the CBMN-cyt assay parameters were comparable between PZOI and Hitnü populations outside the zone of influence of mining activities (POZOI); however, a non-significant incremental trend among individuals from the PZOI for most of the DNA damage parameters was also observed. In agreement with these observations, levels of 1-OHP were also identified as a risk factor for increased MN frequency (PR = 1.20) compared to POZOI (PR = 0.7). Proximity to oil exploitation areas also constituted a risk factor for elevated frequencies of nucleoplasmic bridges (NPBs) and APOP-type cell death. Our results suggest that genetic instability and its potential effects among Hitnü individuals from PZOI and POZOI could be modulated by the combination of multiple factors, including the levels of 1-OHP in urine, malnutrition, and some traditional consumption practices.

Factores ambientales en la transmisión del SARS-CoV-2/COVID 19: panorama mundial y colombiano / Environmental factors in the transmission of SARS-COV-2/COVID 19: World and Colombian outlook

Resumen Introducción: Diversas investigaciones han intentado establecer el impacto de algunos parámetros meteorológicos y de calidad del medio ambiente en la transmisión del SARS-CoV-2, tomando en consideración las características geográficas de cada país y con el fin de mitigar el avance de la enfermedad mediante el control de esos factores. Objetivo: Analizar la evidencia existente sobre la posible relación entre factores ambientales y la morbilidad y mortalidad por SARS-CoV-2/COVID-19 en el panorama mundial y colombiano. Metodología: Se realizó una revisión exhaustiva de la literatura científica en las bases de datos electrónicas. Además, se analizó el impacto de algunas variables ambientales y la gravedad de los casos de COVID-19 durante el período del 8 de abril al 29 de julio de 2020 en la ciudad Bogotá. Resultados: El análisis correlacional entre la ocupación de camas UCIs en Bogotá con los factores ambientales como temperatura, las concentraciones de PM2 5, O3, NO, NO2 y CO mostraron una relación inversamente significativa. Entre tanto, se presentó una correlación positiva entre los niveles de óxidos de nitrógeno (NO/NO2) y el monóxido de carbono (CO). Algunos de estos resultados posiblemente están relacionados con los efectos de la cuarentena impuesta por el gobierno local. Conclusión: Nivel mundial existe suficiente evidencia para relacionar algunas condiciones y parámetros ambientales con un aumento en la morbilidad y mortalidad por COVID-19. Las evidencias a nivel nacional aún son escasas.

Abstract Introduction: Several investigations have attempted to establish the impact of some meteorological and environmental parameters on the transmission of SARS-CoV-2, considering each country's geographical characteristics and seeking to mitigate the disease's advancement by controlling these factors. Objective: Analyze the evidence on the possible relationship between environmental factors, morbidity, and mortality due to SARS-CoV-2/COVID-19, both globally and within Colombia. Methodology: A comprehensive review of the scientific literature was carried out in the electronic databases. Additionally, the impact of some environmental variables and the severity of COVID-19 cases were analyzed during the period from April 8 to July 29, 2020, for the city of Bogotá. Results: The correlational analysis between the ICU admission rates in Bogotá and the environmental factors like temperature, PM2 5, O3, NO, NO2 y CO levels, and ozone concentration showed an inversely significant relationship. Meanwhile, there was a positive correlation between the levels of nitrogen oxides (NO/NO2) and carbon monoxide (CO). Some of these results could be related to the effects of the quarantine imposed by local governments. Conclusion: Globally, there is enough evidence to link environmental conditions and parameters with increased morbidity and mortality for COVID-19. Evidence at the national level is still scarce.

Dietary exposure to mercury and its relation to cytogenetic instability in populations from "La Mojana" region, northern Colombia.

Fish consumption and chronic exposure to low doses of mercury (Hg) seems to activate several molecular mechanisms leading to carcinogenic and/or teratogenic processes. However, Hg genotoxic effects on humans are not completely described. In the present study, we assessed cytogenetic damage in isolated human peripheral lymphocytes using the cytokinesis-block micronucleus cytome assay (CBMN-Cyt), micronucleus formation with anti-kinetochore antibody (CREST staining), levels of total Hg in hair (T-Hg), fish consumption, and estimated Hg dose. The study comprised 39 non-exposed, and 73 residents from La Mojana region, an area with a well-documented Hg contamination. Data showed a significant increase in micronuclei (MNBN), nucleoplasmic bridges (NPB), and necrotic and apoptotic cell frequencies in residents of "La Mojana." The overall mean T-Hg level in hair for exposed residents was 1.12 ± 0.94 mg kg-1 and 0.15 ± 0.05 in individuals from the reference area. Approximately 40% of analyzed individuals showed T-Hg levels that exceeded US Environmental Protection Agency (USEPA) reference dose. Increased T-Hg levels in hair were related to increased MNBN frequencies and high fish consumption. Other cellular markers, such as necrotic and apoptotic cell frequencies, were also correlated with high fish intake and T-Hg contents. Results of the CREST staining demonstrated that in vivo exposure to Hg induces genetic instability by chromosome fragment loss (clastogenic). Additionally, a high average intake of some fish species, particularly with carnivorous habits like Caquetaia kraussii, Hoplias malabaricus, and Sorubin cuspicaudus, seems to increase MNBN frequencies significantly.

Nuclear factor erythroid 2 - related factor 2 and its relationship with cellular response in nickel exposure: a systems biology analysis.

BACKGROUND: Nickel and nickel-containing compounds (NCC) are known human carcinogens. However, the precise molecular mechanisms of nickel-induced malignant transformation remain unknown. Proposed mechanisms suggest that nickel and NCC may participate in the dual activation/inactivation of enzymatic pathways involved in cell defenses against oxidative damage, where Nuclear factor-erythroid 2 related factor 2 (Nrf2) plays a central role. METHODS: For assessing the potential role of proteins involved in the Nrf2-mediated response to nickel and NCC exposure, we designed an interactome network using the STITCH search engine version 5.0 and the STRING software 10.0. The major NCC-protein interactome (NCPI) generated was analyzed using the MCODE plugin, version 1.5.1 for the detection of interaction modules or subnetworks. Main centralities of the NCPI were determined with the CentiScape 2.2 plugin of Cytoscape 3.4.0 and main biological processes associated with each cluster were assessed using the BiNGO plugin of Cytoscape 3.4.0. RESULTS: Water-soluble NiSO4 and insoluble Ni3S2 were the most connected to proteins involved in the NCPI network. Nfr2 was detected as one of the most relevant proteins in the network, participating in several multifunctional protein complexes in clusters 1, 2, 3 and 5. Ontological analysis of cluster 3 revealed several processes related to unfolded protein response (UPR) and response to endoplasmic reticulum (ER) stress. CONCLUSIONS: Cellular response to NCC exposure was very comparable, particularly concerning oxidative stress response, inflammation, cell cycle/proliferation, and apoptosis. In this cellular response, Nfr2 was highly centralized and participated in several multifunctional protein complexes, including several related to ER-stress. These results add evidence on the possible Ni2+ induced - ER stress mainly associated with insoluble NCC. In this scenario, we also show how protein degradation mediated by ubiquitination seems to play key roles in cellular responses to Ni.

Genetic damage in environmentally exposed populations to open-pit coal mining residues: Analysis of buccal micronucleus cytome (BMN-cyt) assay and alkaline, Endo III and FPG high-throughput comet assay.

DNA and chromosomal damage in individuals occupationally exposed to coal mining residues have repeatedly been reported in lymphocytes and epithelial cells, suggesting a systemic exposure-response in which generation of oxidative damage may play a major role. Nevertheless, the understanding of this mechanism is still incomplete, particularly in regard to environmental exposures. This study aimed to evaluate DNA damage using the cytome assay (BMN-cyt) in buccal cells and its relation to primary and oxidative DNA damage in lymphocytes, assessed by the high-throughput alkaline and modified (FPG-ENDO III) Comet assay in individuals with environmental exposure to coal mining residues in northern Colombia. Considering metals from coal mining activities as the main source of reactive oxygen species (ROS) generation, the concentrations of inorganic elements in blood samples was also assessed. The analysis revealed that frequencies of BMN-cyt parameters related to DNA damage (micronuclei), cytokinesis (binucleated cells) and cell death (condensed chromatin, karyorrhexis, pyknosis and karyolysis) were significantly higher in individuals that were environmentally exposed to coal compared to the unexposed group. The level of % Tail DNA in the alkaline and the modified Comet assay was 4.0 and 4.3 times higher among exposed individuals than in unexposed controls respectively. Increased MN frequencies in buccal cells were correlated with increased %Tail DNA in alkaline and FPG Comet assay. Additionally, exposed individuals had higher concentrations of Cr, Ni, Mn, and Br in the blood compared to unexposed controls. %Tail DNA in alkaline Comet assay was highly correlated with Al, Mn, and Br concentrations, while %Tail DNA in the FPG Comet assay correlated with Mn levels. These results suggest that oxidative damage, particularly purine oxidation, may play an essential role in DNA damage in individuals exposed to coal residues and that some inorganic elements are related to this effect.

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 PM2.5 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 PM2.5, 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 PM2.5 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.

Crustáceos decápodos de la cuenca del río sinú, córdoba, colombia / Decapod Crustaceans of the Sinu River Basin, Cordoba, Colombia

Para evaluar la composición, abundancia y distribución de los crustáceos decápodos en la cuenca del río Sinú, departamento de Córdoba (Colombia), se estudiaron ocho localidades: cuatro en el río Sinú y cuatro en el complejo cenagoso del bajo Sinú. Para ello, se realizaron seis muestreos entre abril de 2005 y mayo de 2006. En total se registraron 458 crustáceos decápodos distribuidos en tres familias, seis géneros y ocho especies. La familia mejor representada fue Trichodactylidae con cuatro géneros y cuatro especies, seguida de Palaemonidae con un género y tres especies, mientras que de la familia Atyidae solo registró una especie. Especies como Macrobrachium carcinus y M. acanthurus, presentaron el rango más amplio de distribución, siendo características tanto para el río Sinú como para el CCBS. Entre las especies identificadas, Atya crassa en el río Sinú y Trichodactylus quinquedentatus en el CCBS son nuevos registros para el departamento de Córdoba.

To review the composition, abundance and distribution of decapod crustaceans in the Sinu river basin, Department of Cordoba (Colombia) eight locations were studied: four on the Sinu River and four in the Low Complex Swampy Sinu. For that, six samplings between April 2005 and May 2006 were made. In total 458 decapod crustaceans were recorded distributed into three families, six genus and eight species. The family best represented was Trichodactylidae with four genus and four species, followed by Palaemonidae with one genus and three species, while family Atyidae recorded only one species. Species such as Macrobrachium carcinus and M. acanthurus presented the wider range of distribution for both the Sinu River as the Low Complex Swampy Sinu. Among the identified species Atya crassa in the Sinu River and Trichodactylus quinquedentatus in the Low Complex Swampy Sinu are new records for the Department of Cordoba.