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RESUMEN En octubre de 2015 el depósito de transformadores fuera de uso de la Administración Nacional de Electricidad (ANDE) ubicado en San Lorenzo (Paraguay), sufrió un incendio de gran magnitud, con destrucción de transformadores, condensadores, y otros materiales que pudieron contener bifenilopoliclorados (PCBs), considerados compuestos orgánicos persistentes, de baja toxicidad aguda, clasificados como cancerígenos (Grupo1) por la Agencia Internacional para la Investigación sobre el cáncer (IARC). Niveles de PCBs en plasma son considerados biomarcadores de exposición al agente químico. El objetivo del trabajo fue describir los casos toxicológicos por exposición al incendio de transformadores fuera de uso, según síntomas manifestados, actividades relacionadas al incendio y resultados del biomarcador de exposición. En este estudio observacional descriptivo de corte transversal, se estudiaron 190 historias clínicas del Centro Nacional de Toxicología (CNTox), hasta 29 días posteriores al incendio, que contaban con resultados del biomarcador determinado por GC/MS. Se detectó el biomarcador hasta 13 días después del incendio. Se observaron niveles plasmáticos de PCBs

Biomarkers of exposure to chemicals, such as styrene, allows to estimate the exposure to a particular compound by measuring the compound or it(s) metabolite(s) in body fluids. As an example, the determination of mandelic acid and phenylglyoxylic acid in urine. Indicators of genotoxicity are categorized as: (a) DNA and protein adducts; (b) DNA strand breaks. Styrene metabolism is initiated by Cytochrome P450 enzymes mediated by the oxidation of styrene to a reactive metabolite, the styrene-7,8-oxide. This study aims to review the environmental monitoring, complemented with biomarkers of exposure in order to understand its correlation and styrene genotoxicity. Systematic searches were performed to identify studies of occupational exposure to styrene and health effects in workers of chemical industries. To determine styrene air concentration, several studies used a personal air sampling method. A significant correlation has been found between styrene air concentration and mandelic and phenylglyoxylic acid concentration in urine. A significant relationship was found between individual levels of mandelic acid and phenylglyoxylic acid and styrene-7,8-oxide adducts to N-terminal valine in hemoglobin among exposed individuals. A strong correlation was also found between the frequency of DNA single-strand breaks, in mononuclear leukocytes, and styrene airborne level. The relationship between DNA damage, persistence and repair is complex, which complicates the relevance evaluation of potential genotoxic exposures difficult. There is conflicting evidence on the relationship between genotoxic response and exposure level. In future individual susceptibility studies, the individual genotypes associated with the metabolic route and DNA damage of styrene (metabolizing enzymes and DNA repair enzymes) should be analyzed. From the analysis of several studies it was found that indeed there is a strong correlation between the exposure levels and exposure biomarkers; however, no evidence was found regarding the styrene genotoxicity. RESUMO - Os biomarcadores de exposição a químicos, como o estireno, indicam que a exposição a um composto específico ocorre através da medição do composto inalterado ou do(s) seu(s) metabolito(s) nos fluídos corporais, como o ácido mandélico e o ácido fenilglioxílico presentes na urina. Os indicadores de genotoxicidade enquadram-se nas seguintes categorias: (a) adutos de proteínas e ADN; (b) quebras de ADN. O metabolismo do estireno é iniciado pelas enzimas do sistema citocromo P450, mediante a oxidação do estireno para um metabolito reativo, o 7,8-oxido de estireno. O presente estudo tem como objetivo a revisão de literatura relacionada com a monitorização ambiental do estireno e a existência de biomarcadores de exposição de forma a compreender a sua correlação com a genotoxicidade do estireno. Realizaram-se pesquisas sistemáticas para identificar estudos distintos de exposição ocupacional ao estireno e os seus efeitos na saúde de trabalhadores de indústrias químicas. Em resultado dessa pesquisa verificou-se que vários estudos referem a utilização de amostragem de ar pessoal para a determinação da concentração de estireno. Uma forte e significativa correlação foi encontrada entre a concentração de estireno no ar e a concentração de ácido mandélico e o fenilglioxílico na urina. Uma correlação significativa entre os níveis individuais de ácido mandélico e fenilglioxílico e a presença de adutos de 7,8-oxido de estireno no N-terminal da valina da hemoglobina foi igualmente encontrada nos indivíduos expostos a concentrações mais elevadas de estireno. Estes adutos de 7,8-oxido de estireno e hemoglobina persistem durante a vida útil dos eritrócitos. Estudos revelam também uma forte relação entre a frequência de quebras da cadeia simples do ADN nos leucócitos mononucleares e o nível de estireno presente no ar. A relação entre as lesões, a sua persistência e a reparação do ADN é complexa, o que dificulta a avaliação da relevância de potenciais exposições a substâncias genotóxicas. Existem evidências conflituantes da relação entre a resposta genotóxica e o nível de exposição. Como tal, os estudos sobre a suscetibilidade individual devem analisar e associar os genótipos individuais com a via metabólica do estireno e a lesão no ADN (metabolizando enzimas e enzimas de reparação do ADN). Concluiu-se que existe uma forte correlação entre os níveis de exposição e os biomarcadores de exposição. No entanto, não foram encontradas provas quanto à genotoxicidade do estireno. info:eu-repo/semantics/publishedVersion

Biomarkers of exposure to chemicals, such as styrene, allow estimating the exposure to a particular compound by measuring the compound or it(s) metabolite(s) in body fluids. An example is the determination of mandelic acid and phenylglyoxylic acid in urine. Indicators of genotoxicity are categorized as: (a) DNA and protein adducts; (b) DNA strand breaks. Styrene metabolism is initiated by Cytochrome P450 enzymes mediated by the oxidation of styrene to a reactive metabolite, the styrene-7,8-oxide. This study aims to review the environmental monitoring, complemented with biomarkers of exposure in order to understand its correlation and styrene genotoxicity. Systematic searches were performed to identify studies of occupational exposure to styrene and its health effects on workers in chemical industries. To determine styrene air concentration, several studies used a personal air sampling method. A significant correlation has been found between styrene air concentration and mandelic and phenylglyoxylic acid concentration in urine. A significant relationship was found between individual levels of mandelic acid and phenylglyoxylic acid and styrene-7,8-oxide adducts to N-terminal valine in hemoglobin among exposed individuals. A strong correlation was also found between the frequency of DNA single-strand breaks, in mononuclear leukocytes, and styrene airborne levels. The relationship between DNA damage, persistence, and repair is complex, which complicates the relevance evaluation of potential genotoxic exposures difficult. There is conflicting evidence on the relationship between genotoxic response and exposure level. In future individual susceptibility studies, the individual genotypes associated with the metabolic route and DNA damage of styrene (metabolizing enzymes and DNA repair enzymes) should be analyzed. From the analysis of several studies, it was found that indeed there is a strong correlation between the exposure levels and exposure biomarkers; however, no evidence was found regarding styrene genotoxicity., Saúde e Tecnologia, N.º 18 (2017): Novembro 2017

The toxicities of phenanthrene (PH) and pyrene (PY) are less than benzo (a) pyrene (BaP) , but both compounds are found in higher concentrations in the air, feed, and food. Most PAHs are metabolized to hydroxylated compounds by the hepatic cytochrome P450 monooxigenases system. Metabolites are excreted into urine and feces. We determined concentrations of PH, PY and BaP in muscle and hydroxylated metabolites, 3-OH-PH, 1-OH-PY, and 3-OH-BaP, respectively, in urine from dairy cattle (n = 24) . We also evaluated the relationship between parent compounds in muscle and their metabolites in urine. Concentrations of PH and PY in muscle ranged from 0.7~4.8 ng/g (1.8 ± 1.7) and 0.4~4.1 ng/g (1.2 ± 1.2) , respectively. Concentrations of 3-OH-PH and 1-OH-PY in urine ranged from 0.1~5.9 ng/ml (2.9 ± 3.7) and 0.5~3.6 ng/ml (1.9 ± 2.3) , respectively. Correlation coefficient for PY concentration in muscle versus 1-OH-PY in urine was 0.657 and for PH concentration in muscle versus 3-OH-PH in urine was 0.579.Coefficient determination for PY and PH concentrations in muscle was 0.886 and for 1-OH-PY and 3-OHPH in urine was 0.834. This study suggests that 1-OH-PY and 3-OH-PH could be used as biomarkers for PAHs exposure in dairy cattle.

The acclimation possibilities to copper in Bufo arenarum embryos was evaluated by means of three different low level copper exposure conditions during 14 days. By the end of the acclimation period the copper content in control embryos was 1.04 ± 0.09 µg.g -1 (wet weight) while in all the acclimated embryos a reduction of about 25% of copper was found. Thus copper content could be considered as a biomarker of low level exposure conditions. Batches of 10 embryos (by triplicate) from each acclimation condition were challenged with three different toxic concentrations of copper. As a general pattern, the acclimation protocol to copper exerted a transient beneficial effect on the survival of the Bufo arenarum embryos. The acclimation phenomenon could be related to the selection of pollution tolerant organisms within an adaptive process and therefore the persistence of information within an ecological system following a toxicological stressor. Keywords: Copper; acclimation; amphibian embryos; tissue residues; exposure biomarker

BACKGROUND: Exposomics is the cutting-edge concept of screening the environmental risk factors for disease. In the novel "top-down" approach, we estimate the molecular exposome by measuring all body fluid analytes in a case-controlled study. However, to detect diverse pollutants, a sufficient sample size and multiple analytical methods are required. This may lead to dramatically increased costs and research workload. METHODS: To help reduce complexity, we suggest a sample pooling strategy along with a scheme for combining both general unknown or multi-targeted screening with targeted analysis. The sample pooling method was tested using computer simulations. RESULTS: By comprehensively analysis of pooled samples, it is possible to identify environmental risk factors. Factors are initially screened in the pooled case and control population samples, then in the randomized grouped and pooled case and control subpopulation samples. In the sample grouping, five or more pools were suggested for groups having 30 individuals per pool. CONCLUSIONS: This study suggests that sample pooling is a useful strategy for exposomics research, which provides a hypothesis-free method for pollutant risk screening.

Fluoxetine is a widely used antidepressant frequently found in wastewater treatment plant effluent and in aquatic ecosystems at concentrations below μg/L. Numerous studies have explored the sensitivity of invertebrates to waterborne fluoxetine showing marked differences of sensitivity. In a previous study, the New-Zealand mudsnail, Potamopyrgus antipodarum, and the European valve snail, Valvata piscinalis, were exposed to waterborne fluoxetine (3.7-100 μg/L) during 42 days. While effects were observed on the mudsnail reproduction and F1, the valve snail was not affected. Several assumptions were proposed to explain these results including dissimilar metabolic capacities or bioavailability of fluoxetine for the snails. The aim of this study was to asses if differential sensitivity of gastropods snails to fluoxetine could be explained by its bioaccumulation and metabolism into norfluoxetine.