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Mining is a major economic activity in many developing countries. However, it disturbs the environment, producing enormous quantities of waste, known as mine tailings, which can have deleterious environmental impact, due to their high heavy metals (HM) content. Often, foundation species that establish on mine tailings are good candidates to study the effects of HM bioaccumulation at different levels of biological organization. Prosopis laevigata is considered a HM hyperaccumulator which presents attributes of a foundation species (FS) and establishes naturally on mine tailings. We evaluated the bioaccumulation of Cu, Pb, and Zn in P. laevigata foliar tissue, the leaf micro- and macro-morphological characters, DNA damage, and population genetic effects. In total, 80 P. laevigata individuals (20/site) belonging to four populations: The individuals from both sites (exposed and reference) bioaccumulated HMs (Pb > Cu > Zn). However, in the exposed individuals, Pb and Cu bioaccumulation was significantly higher. Also, a significant effect of macro- and micro-morphological characters was registered, showing significantly lower values in individuals from the exposed sites. In addition, we found significant differences in genotoxic damage in P. laevigata individuals, between the exposed and reference sites. In contrast, for the micro-morphological characters, none of the analyzed metals had any influence. P. laevigata did not show significant differences in the genetic structure and diversity between exposed and reference populations. However, four haplotypes and four private alleles were found in the exposed populations. Since P. laevigata is a species that establishes naturally in polluted sites and bioaccumulates HM in its foliar tissues, the resulting genetic, individual and population effects have not been severe enough to show detrimental effects; hence, P. laevigata can be a useful tool in phytoremediation strategies for soils polluted with Pb and Cu, maintaining its important ecological functions.

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INTRODUCTION: Heavy metals (HM) and polycyclic aromatic hydrocarbons (PAHs) exposition has been associated with health problems. Therefore, this research evaluated genotoxicity induced in male mice strain CD-1 exposed to benzo[a]anthracene (B[a]A) and benzo[a]pyrene (B[a]P) and their interaction with Fe, Pb, and Al. METHODS: Groups of animals were exposed intraperitoneally to HM, PAHs, and mixtures of both. Peripheral blood samples were taken from 0 to 96 h at 24 h intervals; genotoxicity was determined by micronucleus tests and comet assay. Additionally, toxicity and viability were evaluated. RESULTS: HM and PAHs individually were genotoxic. About toxicity, only Al altered polychromatic erythrocytes number and did not change leukocytes viability. Concerning mixtures, Fe + B[a]P, Fe + B[a]A, Pb + B[a]P increased genotoxicity. There were no changes with Pb + B[a]A. Finally, Al mixtures with both PAHs damage was decreased. CONCLUSIONS: Exposure to HM and PAH caused genetic damage. Fe, Al, and B[a]A, established a genotoxic potential. Every metal can interact with PAHs in different ways. Also, the micronucleus test and the comet assay demonstrated their high capacity and reliability to determine the genotoxic potential of the compounds evaluated in this work.

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Mexico is a country where agricultural activity is of great importance, but biomonitoring data are still scarce. With more intensive pesticides use per unit area/surface in horticultural productivity, there is a higher impact on environmental contamination and workers' health. Considering that exposure to various pesticide and pesticide mixtures represents an additional genotoxic risk, the appropriate characterization of exposure, confounding factors and the risk itself are very much needed. We compared genetic damage in 42 horticulturists and 46 unexposed controls (Nativitas, Tlaxcala) using alkaline comet (whole blood) and micronucleus (MN) test with nuclear abnormalities (NA) (buccal epithelial cells). Workers demonstrated significantly higher levels of damage (TI%=14.02 ± 2.49 vs. 5.37 ± 0.46; MN=10.14 ± 5.15 vs. 2.40 ± 0.20), with more than 90% of them not using protective clothing nor gloves during application. Combined DNA damage techniques and periodic monitoring together with educational programs for safe pesticide application is the best strategy to assess and prevent workers' health risks.

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Agriculture has been and still is one of the most influential primary operations in economic history worldwide. Its social, cultural, and political impact allows the progression and survival of humanity. Sustaining the supply of primary resources is crucial for the future. Therefore, the development of new technologies applied to agrochemicals is growing to obtain better food quality faster. Recently, nanotechnology has gained strength in this field in the last decade, mainly because of the presumed benefits that will carry with it compared with the current commercial presentations, like the decrease of risk in non-target organisms. The harm of pesticides is commonly associated with unwanted effects on human health, some with long-term genotoxic effects. Therefore, it would be relevant to set the existence of a risk or a benefit of the nanopesticides from a genotoxic point of view, comparing against those without this technology. Although some studies are concerned with its genotoxicity in live aquatic organisms, few focus on human in vitro models. Several studies conclude that some of them can induce oxidative stress, leading to DNA damage or cell death. However, there is still much to investigate to establish an accurate and complete assessment. In this review, we aim to give an overview of the genotoxic effect caused by nanopesticides in animal cells and a guide to the evolution of this topic, offering a base and critical review to facilitate future research.

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Introducción. Las PM2.5 son componentes de la atmósfera de la Ciudad de México. Contienen, entre otros compuestos, los hidrocarburos aromáticos policíclicos, que tienen efectos tóxicos conocidos. Debido a las diferencias en la composición de las PM2.5 en las diferentes zonas de la Ciudad de México, y la falta de información sobre sus efectos, el objetivo del estudio fue evaluar la cito y genotoxicidad de la fracción orgánica soluble que contienen los hidrocarburos aromáticos policíclicos, de las PM2.5 provenientes de las estaciones de monitoreo Noreste (NE), Centro (C) y Suroeste (SO) de la Ciudad de México, en cultivo de células NL-20 humanas durante 24 horas. Métodos. Se extrajo la fracción orgánica soluble de los filtros con las PM2.5 de las diferentes estaciones de monitoreo. Se cultivaron las células bronquiales humanas y, posteriormente, se realizaron los ensayos de exposición a la fracción orgánica soluble para evaluar el efecto en la viabilidad y en la inducción de genotoxicidad. Resultados. Los resultados mostraron que 0.1 μg/μl de fracción orgánica soluble de la estación Centro fue la más citotóxica, reduciendo a 52.4% y 54.2% la viabilidad celular, en las temporadas tanto de sequía como de lluvia, respectivamente. Esta fracción orgánica soluble indujo anormalidades celulares, como multinucleación y atipia nuclear. Los porcentajes contrastaron con los obtenidos de la estación NE que fueron 91.2% y 85% a la misma concentración, respectivamente (p <0.05). La concentración de 0.1 μg/μl, tanto de la estación NE como de la del C, fue genotóxica. Conclusiones. La fracción orgánica soluble de la zona Centro fue la más citotóxica, ya que es la zona con mayor concentración de automóviles que son la fuente principal de hidrocarburos aromáticos policíclicos.

Background. PM2.5 are components of the atmosphere of Mexico City and contain polycyclic aromatic hydrocarbons (PAH), which induce toxic effects. Due to different compositions of the PM2.5 in all zones of Mexico City and the lack of information about their effects, the main purpose of this study was to evaluate the cytotoxicity and genotoxicity due to soluble organic fractions (SOFs), which contains PAH isolated from the PM2.5 collected from several monitoring stations in Mexico City (northeast, downtown, and southwest) in a cell culture of human line NL-20 during a 24-h period. Methods. We extracted the soluble organic fraction of PM2.5 filters from the different monitoring stations. Human bronchial cells were cultured and subsequently assays were performed on the exposure of SOFs to evaluate the effect on the viability and induction of genotoxicity. Results. Results show that 0.1 μg/μl of SOF from the downtown station was more cytotoxic, reducing cell viability to 52.4% and 54.2% in both dry and rainy periods, respectively. Also, cellular anomalies were induced such as multinucleation and nuclear atypia. These percentages of cytotoxicity contrasted against those obtained from SOFs from the northeast area that were 91.2% and 85% at the same concentration during both dry and rainy periods, respectively (p <0.05). Only at 0.1 μg/μl SOF were the results genotoxic from the northeast and downtown (p <0.05). Conclusions. SOFs from the downtown zone were the most cytotoxic due to the high concentration of automobiles as the main sources of PAH.

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The plant cell/microbe coincubation assay was used to analyze organophosphorus insecticide activation. Salmonella typhimurium strains TA98 and TA100 were exposed to several concentrations of the pesticides phoxim and azinphos methyl with and without TX1 cell line of Nicotiana tabacum activation. When the bacterial strains were treated directly with phoxim, mutagenic activity increased significantly. In contrast, no mutagenic activity was detected with plant activation. Azinphos methyl inhibited the growth of Salmonella strains without plant activation. The coincubation with N. tabacum increased mutagenic activity significantly. These findings and those obtained in animals demonstrated that azinphos-methyl was an indirect mutagen or pro-mutagen activated by the plant metabolism.

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