Spatial pattern of the environmental exposure to tin in the vicinity of an alloy industry in Volta Redonda, Rio de Janeiro State, Brazil.

Despite being widely used in industry, the literature on tin and its effects in humans is scarce, especially regarding reference values in biological indicators such as blood and urine. Similarly, environmental limits are also rare. This study sought to assess the spatial distribution of hotspots in the environmental exposure to tin in the vicinity of an alloy industry in the south region of the state of Rio de Janeiro, Brazil. The study population consisted of 74 adults. Graphite furnace atomic absorption spectrometry determined tin in all samples. Households and points around the industry were georeferenced with the use of GPS to identify the most intense tin sites. Results of the first and second campaigns ranged from 0.022 to 0.153 and 0.003 to 0.445µg m-3 for the atmospheric air, whereas such ranges were 0.64 to 1.61 and 1.97 to 8.54µg m-2 for household dust, respectively. The mean tin concentration found in the blood of the population was 3.85 ± 1.57µg L-1. In urine the value was 3.56 ± 1.88µg L-1. The kernel map showed the highest spatial concentrations of tin in household dust in the eastern region of the industry. In the first sampling, atmospheric air samples presented the most elevated concentrations in the southwest and southeast. Although the direction of the wind was northwest, potentially high risks were concentrated in the central area in the second collection. The largest hotspots were in the north, south and southeast regions; however, urine samples showed medium to high levels in the west and east regions. Regarding blood samples, the greatest difference was the absence of hotspot areas in the west. Environmental monitoring becomes necessary to better assess the exposure to tin.

Monoalkyl Tin Nano-Cluster Films Reveal a Low Environmental Impact under Simulated Natural Conditions.

Recently, monoalkyl oxo-hydroxo tin clusters have emerged as a new class of metal-oxide resist to support the semiconductor industry's transition to extreme ultraviolet (EUV) lithography. Under EUV exposure, these tin-based clusters exhibit higher performance and wider process windows than conventional polymer materials. A promising new monoalkyl precursor, [(BuSn)12 O14 (OH)6 ][OH]2 (BuSn), is still in its infancy in terms of film formation. However, understanding potential environmental effects could significantly affect future development as a commercial product. We synthesized and explored the toxicity of nano-BuSn in the alga Chlamydomonas reinhardtii and the crustacean Daphnia magna at exposure concentrations ranging from 0 to 250 mg/L. Nano-BuSn had no effect on C. reinhardtii growth rate irrespective of concentration, whereas high nanoparticle concentrations (≥100 mg/L) increased D. magna immobilization and mortality significantly. To simulate an end-of-life disposal and leachate contamination, BuSn-coated film wafers were incubated in water at various pH values and temperatures for 14 and 90 d to investigate leaching rates and subsequent toxicity of the leachates. Although small quantities of tin (1.1-3.4% of deposited mass) leached from the wafers, it was insufficient to elicit a toxic response regardless of pH, incubation time, or temperature. The low toxicity of the tin-based thin films suggests that they can be an environmentally friendly addition to the material sets useful for semiconductor manufacturing. Environ Toxicol Chem 2019;38:2651-2658. © 2019 SETAC.

Empirical investigation of preparations produced according to the European Pharmacopoeia monograph 1038.

According to the European Pharmacopoeia monograph 1038 (Praeparationes homoeopathicae), homeopathic preparations are produced by successive dilution and succussion steps. Dilution levels beyond Avogadro's limit, however, render specific effects implausible according to standard scientific knowledge. Accordingly, we were interested in a critical empirical investigation of preparations produced according to this monograph. Within a precursor study we developed a bioassay based on a fingerprint metabolomic analysis of Lepidium sativum seeds germinated in vitro in either homeopathic preparations or controls in a blinded and randomized assignment. Results of the precursor study were not consistent with the hypothesis that the effects of a Stannum metallicum 30x preparation are identical to placebo. In the present study we investigated the reproducibility of these effects after scrutinizing and optimizing experimental procedures. Ten independent experiments were performed in a blinded and randomized assignment in two independent laboratories. Additionally, 10 systematic negative water control experiments were performed in both laboratories to critically assess the stability of the experimental set-up. The effects of the Stannum metallicum 30x treatment were reproduced. The systematic negative control experiments did not yield false-positive results, indicating a stable experimental set-up. We thus repeatedly observed biological effects conflicting with the assumption that Stannum metallicum 30x is identical to placebo. We therefore wish to discuss whether these findings are to be considered a scientific anomaly or whether they might stimulate further investigations to clarify whether application of the European Pharmacopoeia monograph 1038 may result in pharmaceutical preparations with specific effects.

Spatial pattern of the environmental exposure to tin in the vicinity of an alloy industry in Volta Redonda, Rio de Janeiro State, Brazil / Padrão espacial da exposição ambiental ao estanho nos arredores de uma indústria de ligas metálicas em Volta Redonda, Estado do Rio de Janeiro, Brasil / Patrón espacial de exposición ambiental al estaño en las proximidades de una industria de aleación en Volta Redonda, estado de Río de Janeiro, Brasil

Abstract: Despite being widely used in industry, the literature on tin and its effects in humans is scarce, especially regarding reference values in biological indicators such as blood and urine. Similarly, environmental limits are also rare. This study sought to assess the spatial distribution of hotspots in the environmental exposure to tin in the vicinity of an alloy industry in the south region of the state of Rio de Janeiro, Brazil. The study population consisted of 74 adults. Graphite furnace atomic absorption spectrometry determined tin in all samples. Households and points around the industry were georeferenced with the use of GPS to identify the most intense tin sites. Results of the first and second campaigns ranged from 0.022 to 0.153 and 0.003 to 0.445µg m-3 for the atmospheric air, whereas such ranges were 0.64 to 1.61 and 1.97 to 8.54µg m-2 for household dust, respectively. The mean tin concentration found in the blood of the population was 3.85 ± 1.57µg L-1. In urine the value was 3.56 ± 1.88µg L-1. The kernel map showed the highest spatial concentrations of tin in household dust in the eastern region of the industry. In the first sampling, atmospheric air samples presented the most elevated concentrations in the southwest and southeast. Although the direction of the wind was northwest, potentially high risks were concentrated in the central area in the second collection. The largest hotspots were in the north, south and southeast regions; however, urine samples showed medium to high levels in the west and east regions. Regarding blood samples, the greatest difference was the absence of hotspot areas in the west. Environmental monitoring becomes necessary to better assess the exposure to tin.

Resumo: O estanho é amplamente utilizado na indústria. A literatura sobre seus efeitos em humanos é escassa, principalmente quanto aos valores de referência em indicadores biológicos como sangue e urina. Também são raros os estudos sobre os limites do estanho no meio ambiente. O estudo teve como objetivo avaliar os pontos críticos da distribuição espacial da exposição ambiental ao estanho nos arredores de uma indústria de ligas metálicas na região sul do Estado do Rio de Janeiro, Brasil. A população do estudo consistiu em 74 adultos. O estanho foi medido em todas as amostras com a espectrometria de absorção atômica em forno de grafite. As residências e outros pontos em torno da indústria foram georreferenciados com GPS para identificar os locais com maior concentração de estanho. Os resultados da primeira e segunda campanhas variaram entre 0,022 e 0,153 e entre 0,003 e 0,445µg m-3 para o ar atmosférico, enquanto para a poeira doméstica as faixas foram 0,64-1,61 e 1,97-8,54µg m-2, respectivamente. A concentração sanguínea média de estanho na população foi 385 ± 1,57µg L-1 e na urina foi 3,56 ± 1,88µg L-1. O mapa kernel mostrou as concentrações mais elevadas de estanho na poeira doméstica nos arredores ao leste da indústria. Na primeira amostragem, o ar atmosférico apresentou as concentrações ao sudoeste e sudeste da fábrica. Entretanto, riscos potencialmente altos estiveram concentrados na área central, embora a direção do vento tenha sido noroeste na segunda coleta de amostras. Os maiores pontos críticos foram ao norte, sul e sudeste da indústria, mas as amostras de urina mostraram níveis moderados a altos ao oeste a ao leste. Nas amostras de sangue, a maior diferença foi a ausência de pontos críticos ao oeste da indústria. O monitoramento ambiental é necessário para melhor avaliar a exposição ao estanho.

Resumen: El uso del estaño está muy generalizado en la industria. La literatura sobre sus efectos en humanos es escasa, especialmente en lo que concierne a los valores de referencia en indicadores biológicos como sangre y orina. Igualmente, los límites ambientales también son raros. El objetivo de este estudio fue evaluar los puntos calientes de la distribución espacial de exposición ambiental al estaño, en las proximidades de una industria de aleación, en el sur del estado de Río de Janeiro, Brasil. El estudio poblacional contó con 74 adultos. La espectrometría de absorción atómica por horno de grafito halló estaño en todas las muestras. Asimismo, las residencias se georreferenciaron con puntos alrededor de la industria mediante GPS para identificar los lugares con mayor intensidad de estaño. Los resultados de la primera y segunda campaña oscilaron de 0,022 a 0,153 y 0,003 a 0,445µg m-3 en aire atmosférico, aunque tales rangos fueron de 0,64 a 1,61 y de 1,97 a 8,54µg m-2 en el caso de polvo doméstico, respectivamente. El promedio de concentración de estaño encontrado en la sangre de la población fue 3.85 ± 1.57µg L-1. Respecto a la orina, este valor fue 3.56 ± 1.88µg L-1. El mapa de kernel expuso que las concentraciones espaciales más altas de estaño en el polvo doméstico de las casas se encontraron en la región oriental de la industria. En la primera muestra, las muestras de aire atmosférico presentaron las concentraciones más elevadas en el suroeste y sureste. No obstante, los riesgos potencialmente altos se concentraron en el área central, a pesar de que la dirección del viento era noroeste en la segunda recogida de muestras. Los puntos calientes más grandes estuvieron en el norte, sur, y sureste. Sin embargo, las muestras de orina mostraron niveles de medios a altos en el oeste y este. Respecto a las muestras de sangre, la diferencia más grande fue la ausencia de áreas calientes en el oeste. El monitoreo ambiental se hace necesario para evaluar mejor la exposición al estaño.

[Zinc- and tin-induced apoptotic mechanisms in immune system and cranial nerve system].

This review explains the mechanisms of apoptosis related to the impacts of zinc deficiency and organotin exposure on the immune and central nervous systems. In the immune systems, both zinc deficiency and trialkyltin exposure lead to severe thymic atrophy and affect T-lymphocyte development through apoptosis of double positive stage pre-T-cells(CD4+/CD8+) in the cortex region. Their apoptosis are caused mainly through decrease in Bcl-2 expression, activation of ROS production/release, oxidative stress, mitochondrial cytochrome c release and activation of caspase cascade, with increases in glucocorticoids in zinc deficiency, without the involvement of glucocorticoid in organotin exposure In the central nervous system, both zinc deficiency and trialkyltin exposure reduce learning, memory and sensory functions through neuronal apoptosis caused by activation of ROS production/release, release of pro-apoptotic factors such as cytochrome c or apoptosis-inducing factor(AIF), with Fe excessive accumulation leading to ROS production and with depletion of hippocampus Zn (mossy fiber Zn) causing various Ca2+ channel disorder of synapse in the hippocampus, and with excessive accumulation of Ca through cAMP-dependent Ca(2+)-channel disorder by excessive PTH and cAMP excessive production in the olfactory systems such as olfactory epithelium and olfactory bulb.

Assessing the toxicity of Pb- and Sn-based perovskite solar cells in model organism Danio rerio.

Intensive development of organometal halide perovskite solar cells has lead to a dramatic surge in power conversion efficiency up to 20%. Unfortunately, the most efficient perovskite solar cells all contain lead (Pb), which is an unsettling flaw that leads to severe environmental concerns and is therefore a stumbling block envisioning their large-scale application. Aiming for the retention of favorable electro-optical properties, tin (Sn) has been considered the most likely substitute. Preliminary studies have however shown that Sn-based perovskites are highly unstable and, moreover, Sn is also enlisted as a harmful chemical, with similar concerns regarding environment and health. To bring more clarity into the appropriateness of both metals in perovskite solar cells, we provide a case study with systematic comparison regarding the environmental impact of Pb- and Sn-based perovskites, using zebrafish (Danio Rerio) as model organism. Uncovering an unexpected route of intoxication in the form of acidification, it is shown that Sn based perovskite may not be the ideal Pb surrogate.

In vitro evaluation of biocompatibility of Ti-Mo-Sn-Zr superelastic alloy.

Shape memory alloys (SMAs) including superelastic alloys have unique properties such as shape memory and superelasticity, thus they are recognized as very useful biomaterials. These properties are very advantageous for medical use, and actually the SMA wires have been widely used in medical field. However, biocompatibility of nickel-titanium (Ni-Ti) alloy, which is the only practical SMA at present, has been questioned because of its high nickel content. The aim of this study was to evaluate the biocompatibility of a newly developed Ni-free Ti-based SMA for medical use. The newly developed SMA made of Ti-Mo-Sn-Zr system was processed into a disk of 15.1 mm in diameter. Pure titanium of the same shape was prepared as control. All the disk surfaces were polished using emery papers, #120, #400, and #600. Scanning electron microscopy and a 3D optics profiler were used to evaluate the surface of the materials. In vitro evaluations included colony examination for evaluation of the cell cytotoxicity, DNA quantification for the cell proliferation, Alamar blue assay for metabolic activity, FDA staining for the live cell imaging, and cell cycle analysis, using Chinese hamster fibroblastic V-79 cells and mouse osteoblastic MC3T3-E1 cells. In colony examination and DNA quantification, there was no significant difference between the Ti-Mo-Sn-Zr and the pure titanium. In FDA staining, cultured cells on the Ti-Mo-Sn-Zr alloy showed the same biocompatibility as those on the pure titanium. The present results suggest that the newly developed Ti-Mo-Sn-Zr alloy showed the high biocompatibility comparable to pure titanium and can be used as efficient biomaterial for medical use.

Feed premix: a difficult matrix for the accurate determination of trace elements - the outcome of IMEP-114 and IMEP-36.

This paper presents the outcome of two proficiency tests (IMEP-114/36) running in parallel, which focused on the determination of total As, Cd, Pb, Hg and Sn in feed premixes. Both exercises aimed to test the performance of laboratories measuring trace elements in feed, in compliance with Directive 2002/32/EC of the European Parliament and of the Council on undesirable substances in animal feed. IMEP-114 was run for the European Union National Reference Laboratories, while IMEP-36 was open to all food control laboratories that wished to participate. In total 80 laboratories from 37 countries registered to both proficiency tests, from which 75 laboratories reported results. The test material used in this exercise was commercially available feed premix, which was processed, bottled, labelled and dispatched to participants. The performance of the participating laboratories was similar in both proficiency tests and was very good in the case of total Cd and less satisfactory for total As and total Pb. For total Sn only one-third of the participants reported results, from which 33% performed satisfactorily. Thirty-four participants reported results for total Hg, although the expert laboratories stated that the mass fraction for that measurand was below the limit of detection of the method used. An evaluation of the reasons that could be at the basis of unsatisfactory results has been carried out and is presented here.

[Potential exposure to carcinogens in low-melting alloys processing]. / Potenziale esposizione a cancerogeni nella lavorazione di leghe bassofondenti.

The objective in our study was to evaluate the worker's exposition to lead and cadmium in 32 radiology technicians in an eastern Sicily hospital in workers of low melting point alloy of lead, tin, cadmium and bismuth (league that can be melted at 73 degrees C as CERROBEND). Such alloy is used for the fabrication of objects used for the personal protection of cancer patients subject to high energy treatment. The parameters taken into consideration for this study were sex, age and smoking habits. In the test subject's working cycle reported in our case, there were traces of smoke formation containing lead, tin, bismuth and cadmium. Cadmium is a substance considered by IARC to be cancerous and can be found in both work and living environments, therefore it is often difficult to establish rather its presence in the organism is due to working activities and/or the living environment. In these cases it is necessary to evaluate whether the work represents an added risk to develop neoplasia, compared to the consequences due to normal environmental exposure. The added risk linked to work is evaluated comparing the concentration of toxic substances found in the living environments (Environmental Reference Value) with the toxic and/or metabolite found in the working environment, and comparing the biological reports of the population not directly exposed by work (Biological Reference Value) and those exposed. We performed a biological monitoring for lead and cadmium on the workers examined. The Italian Legislature, aside from lead, has not yet issued guidelines pertaining to professional exposure to cadmium, and therefore it is mandatory to take reference to the American Hygienist's charts both for environmental exposure (TLVs) andfor biological monitoring (BEI). Biological monitoring, which allows to evaluate the absorption by both inhalation and gastrointestinally, was performed through measuring the levels of lend and cadmium in the bloodstream (PbB and CdB) and the Cd in urine (CdU). The results show that in no case the levels of lead in the bloodstream (PbB) were above the reference value and BEI. The levels of cadmium urine (CdU) weren't above the reference level and the BEI, while the haematic levels of cadmium (CdB) were higher than the reference value in 8 subjects, each long time smokers, each of about 20 cigarettes a day. This data shows how, in the evaluation of exposition to cadmium, aside from the exam of data pertaining to work, the study of ways of absorption and the interpretation of the results of environmental and biological monitoring, it is important to consider the possibility of intoxication outside of the workplace. Cigarette smoke, as already indicated by other authors, is also confirmed in our studies as one of the major fonts of non professionally linked inhalation of cadmium.

Determination of toxic elements (mercury, cadmium, lead, tin and arsenic) in fish and shellfish samples. Risk assessment for the consumers.

Although fish intake has potential health benefits, the presence of metal contamination in seafood has raised public health concerns. In this study, levels of mercury, cadmium, lead, tin and arsenic have been determined in fresh, canned and frozen fish and shellfish products and compared with the maximum levels currently in force. In a further step, potential human health risks for the consumers were assessed. A total of 485 samples of the 43 most frequently consumed fish and shellfish species in Andalusia (Southern Spain) were analyzed for their toxic elements content. High mercury concentrations were found in some predatory species (blue shark, cat shark, swordfish and tuna), although they were below the regulatory maximum levels. In the case of cadmium, bivalve mollusks such as canned clams and mussels presented higher concentrations than fish, but almost none of the samples analyzed exceeded the maximum levels. Lead concentrations were almost negligible with the exception of frozen common sole, which showed median levels above the legal limit. Tin levels in canned products were far below the maximum regulatory limit, indicating that no significant tin was transferred from the can. Arsenic concentrations were higher in crustaceans such as fresh and frozen shrimps. The risk assessment performed indicated that fish and shellfish products were safe for the average consumer, although a potential risk cannot be dismissed for regular or excessive consumers of particular fish species, such as tuna, swordfish, blue shark and cat shark (for mercury) and common sole (for lead).

Synergistic cytotoxic effects of ions released by zinc-aluminum bronze and the metallic salts on osteoblastic cells.

The use of copper-based alloys for fixed dental crowns and bridges is increasingly widespread in several countries. The aim of this work is to study the dissolution of a zinc-aluminum-bronze and the cytotoxic effects of the ions released on UMR-106 osteoblastic cell line. Two sources of ions were used: (1) ions released by the metal alloy immersed in the cell culture and (2) salts of the metal ions. Conventional electrochemical techniques, atomic absorption spectroscopy [to obtain the average concentration of ions (AC) in solution], and energy dispersive X-ray (EDX) spectroscopy analysis were used to study the corrosion process. Corrosion tests revealed a strong influence of the composition of the electrolyte medium and the immersion time on the electrochemical response. The cytotoxicity was evaluated with (a) individual ions, (b) combinations of two ions, and (c) the mixture of all the ions released by a metal disc of the alloy. Importantly, synergistic cytotoxic effects were found when Al-Zn ion combinations were used at concentration levels lower than the cytotoxic threshold values of the individual ions. Cytotoxic effects in cells in the vicinity of the metal disc were also found. These results were interpreted considering synergistic effects and a diffusion controlled mechanism that yields to concentration levels, in the metal surroundings, several times higher than the measured AC value.

Enhanced resistance of yeast mutants deficient in low-affinity iron and zinc transporters to stannous-induced toxicity.

Tin or stannous (Sn(2+)) compounds are used as catalysts, stabilizers in plastic industries, wood preservatives, agricultural biocides and nuclear medicine. In order to verify the Sn(2+) up-take and toxicity in yeast cells we utilized a multi-elemental analysis known as particle-induced X-ray emission (PIXE) along with cell survival assays and quantitative real-time PCR. The detection of Sn(2+) by PIXE was possible only in yeast cells in stationary phase of growth (STAT cells) that survive at 25mM Sn(2+) concentration. Yeast cells in exponential phase of growth (LOG cells) tolerate only micro-molar Sn(2+) concentrations that result in intracellular concentration below of the method detection limit. Our PIXE analysis showed that STAT XV185-14c yeast cells demonstrate a significant loss of intracellular elements such as Mg, Zn, S, Fe and an increase in P levels after 1h exposure to SnCl(2). The survival assay showed enhanced tolerance of LOG yeast cells lacking the low-affinity iron and zinc transporters to stannous treatment, suggesting the possible involvement in Sn(2+) uptake. Moreover, our qRT-PCR data showed that Sn(2+) treatment could generate reactive oxygen species as it induces activation of many stress-response genes, including SOD1, YAP1, and APN1.

In vitro biocompatibility of novel Au-Pt-based metal-ceramic alloys.

The aim of this research was to evaluate the effect of individual metallic elements within experimental Au-Pt-based metal-ceramic alloys on in vitro biocompatibility. A binary Au-10 at.% Pt alloy (AP10) was designed as a parent alloy. Six ternary AP10-X (X = In/Fe/Sn/Zn) alloys and four quaternary (AP10-In2)-Y (Y = Fe/Sn/Zn) with different compositions were cast into square plates with size 10X10X0.5 mm(3) and subjected to porcelain-firing thermal cycling. A commercial alloy was used as a control. In vitro biocompatibility was investigated using L929 murine aneuploid fibrosarcoma cell line. The test samples and cells were incubated at 37°C in a 5% CO(2) atmosphere for 72 h. Alamar™ Blue Assay was carried out to determine the respiratory viability of cultures maintained in the presence of the different materials. The cell only control showed significantly higher levels of cell viability than all six of the ternary alloys and two of the four quaternary alloys, (AP10-In2)-Zn2.1 and (AP10-In2)-Sn1.0 (P < 0.05). The quaternary alloys showed slightly higher levels of cell viability than the ternary alloys, with the exception of AP10-Sn0.9. No statistical differences were seen between the ternary and quaternary alloy groups. Acceptable cell viability was observed on the surfaces of all the alloys.

In vitro effect of lead, silver, tin, mercury, indium and bismuth on human sperm creatine kinase activity: a presumable mechanism for men infertility.

BACKGROUND: The aim of the present study was to investigate the in vitro effects of mercury (Hg+2), lead (Pb+2), silver (Ag+2), tin (Sn+2), bismuth (Bi+3) and indium (In+3) ions on sperm creatine kinase. METHODS: creatine kinase was isolated from human sperm homogenates after chromatography on a DEAE cellulose column. RESULTS: At 60 mug ml-1 metal concentration, 70% of the creatine kinase activity was inhibited by Hg+2, while at the same concentration, Pb+2, Ag+2, Sn+2, Bi+3 and In+3 caused 68%, 66.5%, 65.7%, 64.7% and 62.7% inhibition, respectively. All six metal ions displayed a competitive type of inhibition mechanism for the isolated creatine kinase as analyzed by Lineweaver-Burk plot. Ki values of Hg+2, Pb+2, Ag+2, Sn+2, Bi+3 and In+3 were calculated and 8.34 mM, 5 mM, 4.54 mM, 3.45 mM, 3.12 mM and 2.63 mM values were obtained, respectively. CONCLUSION: All the studied metal ions, at levels of 60 mug ml-1, may reduce normal sperm metabolism by inhibition of sperm creatine kinase, which probably is an important cause of infertility in men. However, further investigations, as in vitro and in vivo, are needed to elucidate the exact mechanism of heavy metals on male reproductive functioning at the molecular level.

Induction of lung epithelial cell transformation and fibroblast activation by Yunnan tin mine dust and their interaction.

Tumor-stroma interactions play a significant role in tumor development and progression. Our study employed an in vitro co-culture model of epithelial cells and fibroblasts to investigate the mechanism of and interaction between lung epithelial cell transformation and fibroblast activation induced by Yunnan tin mine dust. Epithelial cell transformation was evaluated using concanavalin A agglutination and anchorage-independent growth assays, and fibroblast activation was assessed via immunohistochemistry. The TGF-ß1/Smad pathway was monitored by Western blot analysis and ELISA. We found concanavalin A agglutination and anchorage-independent growth assays of dust-exposed epithelial cells were positive, dust-exposed fibroblasts expressed α-SMA, and during the mine dust-induced tumorigenesis, TGF-ß1/Smad signaling pathway changed. In conclusion, Yunnan tin mine dust is able to induce the malignant transformation of bronchial epithelial cells and fibroblast activation. Epithelial cells are the main target of mine dust. Bronchial epithelial cell transformation and fibroblast activation are correlated and synergistic. Their interdependence is related to the TGF-ß1/Smad signaling pathway.

Early life stage and genetic toxicity of stannous chloride on zebrafish embryos and adults: toxic effects of tin on zebrafish.

Humans are exposed to stannous chloride (SnCl(2)), known as tin chloride, present in packaged food, soft drinks, biocides, dentifrices, etc. Health effects in children exposed to tin and tin compounds have not been investigated yet. Therefore, we evaluated the possible teratogenic effects and genotoxic of SnCl(2) in zebrafish (Danio rerio) adults and their embryos. In the embryo-larval study, SnCl(2) showed embryo toxicity and developmental delay after exposure to the various concentrations of 10-250 µM for 120 h. Teratogenic effects including morphological malformations of the embryos and larvae were observed. The embryos exposed to 100 µM displayed tail deformation at 28 hpf and the larvae exposed to 50 µM showed reduced body growth, smaller head and eyes, bent trunk, mild pericardial edema, and smaller caudal fin at 96 hpf. The results of the teratological study show that SnCl(2) induced a significant decrease in the number of living embryos and larvae. Regarding the chromosome analysis, SnCl(2) induced a dose-dependent increase in the micronucleus (MN) frequency in peripheral erythrocytes of adult zebrafish. In blood cells, the 25 µM dose of SnCl(2) caused a nonsignificant increase in the total chromosomal aberrations, but the high doses significantly increased the total number of chromosomal aberrations compared with the control groups. Overall, the results clearly indicate that SnCl(2) is teratogenic and genotoxic to zebrafish.

Abordagem inicial no atendimento ambulatorial em distúrbios neurotoxicológicos. Parte I - metais / Initial approach to outpatient treatment of neurotoxicological disorders. Part I – metals

Introdução: A toxicologia é uma ciência que envolve inúmeros sistemas necessitando de uma equipe multiprofissional e interdisciplinar. A indistinção clínica entre as doenças ocupacionais e não ocupacionais dificulta o seu diagnóstico. Nesse contexto, a neurotoxicologia ocupacional e ambiental estuda os distúrbios do sistema nervoso central (SNC) e periférico (SNP) decorrente da intoxicação dos mais variados agentes. Método: Trata-se de revisão atualizada da literatura a partir de pesquisa na base de dados MEDLINE e LILACS. Também utilizou-se livros e documentos publicados em formato eletrônico. Resultados e Discussão: Distúrbios neuromusculares, distúrbios do movimento, doença do neurônio motor, alterações cognitivocomportamentais e neurofisiológicas têm sido relacionados a inúmeros agentes tóxicos nos últimos anos. A proposta deste artigo é revisar os principais distúrbios neurológicos associados à exposição crônica por metais. A fim de facilitar a abordagem inicial no atendimento ambulatorial aos distúrbios neurotoxicológicos foram confeccionadas tabelas descrevendo os principais agentes tóxicos, as fontes de exposição envolvidas e suasprincipais manifestações neurológicas. Conclusão: Arsênio, chumbo, mercúrio, manganês, cádmio e estanho são alguns metais envolvidos nos distúrbios neurotoxicológicos. Contudo, fica evidente nesta revisão que são necessários novos estudos a fim de determinar a real associação destes e outros metais nos distúrbios crônicos do sistema nervoso central e periférico.

Introduction: Toxicology is a science that involves innumerable systems and requires a multiprofessional and interdisciplinary team. The clinical indistinctiveness of occupational and non-occupational disorders makes their diagnosis difficult. In this context, occupational and environmental toxicology studies the disorders of the central nervous system (CNS) and the peripheral nervous system (PNS) resulting from intoxication by a wide variety of agents. Method: The method consists of an updated review of the literature based on research in the MEDLINE and LILACS databases, as well as books and documents published online. Results and Discussion: Neuromuscular disorders, movement disorders, motor neuron disease, cognitive-behavioral and neurophysiological alterations have been attributed to innumerable toxic agents in recent years. This article proposes to review the main neurological disorders associated with chronic exposure to metals. To facilitate the initial approach to outpatient treatment of neurotoxicological disorders, tables were devised to describe the main toxic agents, the sources of exposure involved and their main neurological manifestations. Conclusions: Arsenic, lead, mercury, manganese, cadmium and tin are some of the metals involved in neurotoxicological disorders. However, this review reveals the need for new studies to determine the real association of these and other metals in chronic disorders of the central and peripheral nervous systems.