Remoção de hidrocarbonetos aromáticos policíclicos em águas utilizando subprodutos da indústria da cortiça

Os Hidrocarbonetos Aromáticos Policíclicos (HAPs) são contaminantes persistentes em meio aquoso. Estes compostos são conhecidos pelas suas propriedades carcinogénicas, mutagénicas e genotóxicas. O principal objetivo deste trabalho consistiu na avaliação das potencialidades de subprodutos da indústria corticeira, como adsorventes alternativos para a remoção de cinco HAPs em meio aquoso: benzo(a)pireno, benzo(ghi)perileno, benzo(b)fluoranteno, benzo(k)fluoranteno e indeno(1,2,3-cd)pireno. A metodologia analítica para quantificar os HAPs envolveu a preparação das amostras, através da técnica de extração em fase sólida (SPE), e a quantificação dos compostos analisados por cromatografia líquida com detetor de fluorescência (LC-FLD). O método foi otimizado e validado, obtendo-se limites de quantificação de 0,004 μg/L para todos os HAPs. Os estudos incidiram na utilização de uma amostra de cortiça, pó de aglomerado de cortiça expandida (PACE), obtida por aglutinação de cortiça em condições hidrotérmicas, a qual nos estudos preliminares revelou desempenho semelhante aos carvões ativados. Com exceção do benzo(ghi)perileno, os resultados mostram que o processo de adsorção dos HAPs na amostra PACE segue uma cinética de pseudo-segunda ordem e as isotérmicas ajustam-se ao modelo de Langmuir.

Contribute of the MYCOMIX project and future perspectives for Human Biomonitoring and health risk assessment in Portugal

There is a growing concern within public health about mycotoxin involvement in human diseases, namely those related to children. The MycoMix project (2012-2015), funded by the Portuguese Foundation for Science and Technology, gathered a multidisciplinary team aiming at answering several questions: 1) Are Portuguese children exposed daily to one or several mycotoxins through food? 2) Can this co-exposure affect children´s health? and 3) Are there interaction effect between mycotoxins? Mycomix results revealed that Portuguese children (< 3 years old, n=103) are exposed to multiple mycotoxins through food consumption. Cumulative risk assessment results revealed a potential health concern for the high percentiles of intake, specially for aflatoxins which are carcinogenic compounds. This fact assumes particular importance considering the interactive effects found in in vitro bioassays. These results highlight the need for a more accurate approach to assess the human exposure to mycotoxins6. Within the Mycomix project the assessment of mycotoxin exposure was based on calculations combining mycotoxin data in food with population data on food consumption. This approach does not consider some aspects as the inter-individual metabolism variation, the exposure through sources other than food and the heterogeneous distribution of mycotoxins in food. Exposure assessment of mycotoxins in Portuguese population through biomarkers is still missing and further studies are urgent to be developed. The European Human Biomonitoring Initiative (EHBMI), a proposal within the European Joint Programme, aims to advance the understanding of the extent of exposure to environmental chemicals across Europe and the impact on human health, by gathering national expertise in human biomonitoring domain. At national level Mycomix project uncovered the potential health risk of exposure of Portuguese children to multiple mycotoxins. The risk assessment expertise acquired within Mycomix, namely in analysis and toxicology of chemical mixtures, will be brought together as a contribute to EHBMI objectives.

Is there a health risk concerning the children´s consumption of cereal-based products? A cumulative mycotoxin risk assessment approach

Historically, the health risk of mycotoxins had been evaluated on the basis of single-chemical and single-exposure pathway scenarios. However, the co-contamination of foodstuffs with these compounds is being reported at an increasing rate and a multiple-exposure scenario for humans and vulnerable population groups as children is urgently needed. Cereals are among the first solid foods eaten by child and thus constitute an important food group of their diet. Few data are available relatively to early stages child´s exposure to mycotoxins through consumption of cereal-based foods. The present study aims to perform the cumulative risk assessment of mycotoxins present in a set of cereal-based foods including breakfast cereals (BC), processed cereal-based foods (PCBF) and biscuits (BT), consumed by children (1 to 3 years old, n=75) from Lisbon region, Portugal. Children food consumption and occurrence of 12 mycotoxins (aflatoxins, ochratoxin A, fumonisins and trichothecenes) in cereal-based foods were combined to estimate the mycotoxin daily intake, using deterministic and probabilistic approaches. Different strategies were used to treat the left censored data. For aflatoxins, as carcinogenic compounds, the margin of exposure (MoE) was calculated as a ratio of BMDL (benchmark dose lower confidence limit) and aflatoxin daily exposure. For the remaining mycotoxins, the output of exposure was compared to the dose reference values (TDI) in order to calculate the hazard quotients (HQ, ratio between exposure and a reference dose). The concentration addition (CA) concept was used for the cumulative risk assessment of multiple mycotoxins. The combined margin of exposure (MoET) and the hazard index (HI) were calculated for aflatoxins and the remaining mycotoxins, respectively. Main results revealed a significant health concern related to aflatoxins and especially aflatoxin M1 exposure according to the MoET and MoE values (below 10000), respectively. HQ and HI values for the remaining mycotoxins were below 1, revealing a low concern from a public health point of view. These are the first results on cumulative risk assessment of multiple mycotoxins present in cereal-based foods consumed by children. Considering the present results, more research studies are needed to provide the governmental regulatory bodies with data to develop an approach that contemplate the human exposure and, particularly, children, to multiple mycotoxins in food. The last issue is particularly important considering the potential synergistic effects that could occur between mycotoxins and its potential impact on human and, mainly, children health.

Characterization of in vitro effects of patulin on intestinal epithelial and immune cells

The intestinal mucosa is the first biological barrier encountered by natural toxins, and could possibly be exposed to high amounts of dietary mycotoxins. Patulin (PAT), a mycotoxin produced by Penicillium spp. during fruit spoilage, is one of the best known enteropathogenic mycotoxins able to alter functions of the intestine (Maresca et al., 2008). This study evaluated the effects of PAT on barrier function of the gut mucosa utilizing the intestinal epithelial cell model Caco-2, and scrutinized immunomodulatory effects using human peripheral blood mononuclear cells (PBMC) and human blood monocyte-derived dendritic cells (moDCs) as test systems. PAT exposure reduced Caco-2 cell viability at concentrations above 12 mM. As expected, the integrity of a polarized Caco-2 monolayer was affected by PAT exposure, as demonstrated by a decrease in TER values, becoming more pronounced at 50 mM. No effects were detected on the expression levels of the tight junction proteins occludin, claudin-1 and claudin-3 at 50 mM. However, the expression of zonula occludens-1 (ZO-1) and myosin light chain 2 (MLC2) declined. Also, levels of phospho-MLC2 (p-MLC2) increased after 24 h of exposure to 50 mM of PAT. T cell proliferation was highly sensitive to PAT with major effects for concentrations above 10 nM of PAT. The same conditions did not affect the maturation of moDC. PAT causes a reduction in Caco-2 barrier function mainly by perturbation of ZO-1 levels and the phosphorylation of MLC. Low doses of PAT strongly inhibited T cell proliferation induced by a polyclonal activator, but had no effect on the maturation of moDC. These results provide new information that strengthens the concept that the epithelium and immune cells of the intestinal mucosa are important targets for the toxic effects of food contaminants like mycotoxins

Micotoxinas – contributos do projeto Mycomix e perspetivas futuras

As micotoxinas são metabolitos secundários produzidos por várias espécies de fungos, e que podem contaminar os alimentos nas diferentes fases de produção, colheita, armazenagem ou processamento. Além de constituir um problema económico e de segurança alimentar, a contaminação de alimentos com micotoxinas é essencialmente um problema de saúde pública, dado que estes compostos podem provocar efeitos graves na saúde humana e animal, estando classificadas pela Agência Internacional de Investigação em Cancro (IARC) como carcinogénicos dos grupos 1, 2B e 3. O projecto Mycomix PTDC/DTP/FTO/0417-2012 (2013-2015), que consistiu num estudo exploratório dos efeitos tóxicos de misturas de micotoxinas em alimentos para crianças revelou a presença de múltiplas micotoxinas em simultâneo em alimentos à base de cereais, indicando que as crianças poderão estar expostas a micotoxinas através da alimentação. No âmbito do projecto Mycomix foi avaliada a exposição de crianças a micotoxinas através da aplicação de diários alimentares para determinação do consumo alimentar. Como alternativa às metodologias de avaliação de risco baseadas no consumo alimentar, a Agência Europeia de Segurança Alimentar (EFSA) recomendou a implementação de metodologias harmonizadas de biomonitorização humana, que é uma metodologia que permite avaliar a exposição do Homem a substâncias naturais e sintéticas do meio ambiente, baseando-se na análise direta de biomarcadores em tecidos e fluidos. É por isso o único método para avaliar diretamente a exposição a determinada substância, a sua magnitude, e a sua variação ao longo do tempo.

Combined exposure to multiple mycotoxins in food: are we ready for risk assessment and risk management?

It is nowadays recognized that the risk of human co-exposure to multiple mycotoxins is real. In the last years, a number of studies have approached the issue of co-exposure and the best way to develop a more precise and realistic assessment. Likewise, the growing concern about the combined effects of mycotoxins and their potential impact on human health has been reflected by the increasing number of toxicological studies on the combined toxicity of these compounds. Nevertheless, risk assessment of these toxins, still follows the conventional paradigm of single exposure and single effects, incorporating only the possibility of additivity but not taking into account the complex dynamics associated to interactions between different mycotoxins or between mycotoxins and other food contaminants. Considering that risk assessment is intimately related to the establishment of regulatory guidelines, once the risk assessment is completed, an effort to reduce or manage the risk should be followed to protect public health. Risk assessment of combined human exposure to multiple mycotoxins thus poses several challenges to scientists, risk assessors and risk managers and opens new avenues for research. This presentation aims to give an overview of the different challenges posed by the likelihood of human co-exposure to mycotoxins and the possibility of interactive effects occurring after absorption, towards knowledge generation to support a more accurate human risk assessment and risk management. For this purpose, a physiologically-based framework that includes knowledge on the bioaccessibility, toxicokinetics and toxicodynamics of multiple toxins is proposed. Regarding exposure assessment, the need of harmonized food consumption data, availability of multianalyte methods for mycotoxin quantification, management of left-censored data and use of probabilistic models will be highlight, in order to develop a more precise and realistic exposure assessment. On the other hand, the application of predictive mathematical models to estimate mycotoxins’ combined effects from in vitro toxicity studies will be also discussed. Results from a recent Portuguese project aimed at exploring the toxic effects of mixtures of mycotoxins in infant foods and their potential health impact will be presented as a case study, illustrating the different aspects of risk assessment highlighted in this presentation. Further studies on hazard and exposure assessment of multiple mycotoxins, using harmonized approaches and methodologies, will be crucial towards an improvement in data quality and contributing to holistic risk assessment and risk management strategies for multiple mycotoxins in foodstuffs.

Application of mathematical models to mycotoxins children risk assessment: a case study of Portuguese children exposure to co-occurring mycotoxins in processed cereal-based foods

People, animals and the environment can be exposed to multiple chemicals at once from a variety of sources, but current risk assessment is usually carried out based on one chemical substance at a time. In human health risk assessment, ingestion of food is considered a major route of exposure to many contaminants, namely mycotoxins, a wide group of fungal secondary metabolites that are known to potentially cause toxicity and carcinogenic outcomes. Mycotoxins are commonly found in a variety of foods including those intended for consumption by infants and young children and have been found in processed cereal-based foods available in the Portuguese market. The use of mathematical models, including probabilistic approaches using Monte Carlo simulations, constitutes a prominent issue in human health risk assessment in general and in mycotoxins exposure assessment in particular. The present study aims to characterize, for the first time, the risk associated with the exposure of Portuguese children to single and multiple mycotoxins present in processed cereal-based foods (CBF). Portuguese children (0-3 years old) food consumption data (n=103) were collected using a 3 days food diary. Contamination data concerned the quantification of 12 mycotoxins (aflatoxins, ochratoxin A, fumonisins and trichothecenes) were evaluated in 20 CBF samples marketed in 2014 and 2015 in Lisbon; samples were analyzed by HPLC-FLD, LC-MS/MS and GC-MS. Daily exposure of children to mycotoxins was performed using deterministic and probabilistic approaches. Different strategies were used to treat the left censored data. For aflatoxins, as carcinogenic compounds, the margin of exposure (MoE) was calculated as a ratio of BMDL (benchmark dose lower confidence limit) to the aflatoxin exposure. The magnitude of the MoE gives an indication of the risk level. For the remaining mycotoxins, the output of exposure was compared to the dose reference values (TDI) in order to calculate the hazard quotients (ratio between exposure and a reference dose, HQ). For the cumulative risk assessment of multiple mycotoxins, the concentration addition (CA) concept was used. The combined margin of exposure (MoET) and the hazard index (HI) were calculated for aflatoxins and the remaining mycotoxins, respectively. 71% of CBF analyzed samples were contaminated with mycotoxins (with values below the legal limits) and approximately 56% of the studied children consumed CBF at least once in these 3 days. Preliminary results showed that children exposure to single mycotoxins present in CBF were below the TDI. Aflatoxins MoE and MoET revealed a reduced potential risk by exposure through consumption of CBF (with values around 10000 or more). HQ and HI values for the remaining mycotoxins were below 1. Children are a particularly vulnerable population group to food contaminants and the present results point out an urgent need to establish legal limits and control strategies regarding the presence of multiple mycotoxins in children foods in order to protect their health. The development of packaging materials with antifungal properties is a possible solution to control the growth of moulds and consequently to reduce mycotoxin production, contributing to guarantee the quality and safety of foods intended for children consumption.

Portuguese children exposure to multiple mycotoxins through food consumption: toward a holistic approach for multiple mycotoxins risk assessment

Humans can be exposed to multiple chemicals at once from a variety of sources, and human risk assessment of multiple chemicals poses several challenges to scientists, risk assessors and risk managers. Ingestion of food is considered a major route of exposure to many contaminants, namely mycotoxins, especially for vulnerable population groups, as children. A lack of sufficient data regarding mycotoxins children risk assessment, could contribute to an inaccuracy of the estimated risk. Efforts must be undertaken to develop initiatives that promote a broad overview of multiple mycotoxins risk assessment. The present work, developed within the MYCOMIX project, aims to assess the risk associated to the exposure of Portuguese children (< 3 years old) to multiple mycotoxins through consumption of foods primarily marketed for this age group. A holistic approach was developed applying deterministic and probabilistic tools to the calculation of mycotoxin daily intake values, integrating children food consumption (3-days food diary), mycotoxins occurrence (HPLC-UV, HPLC-FD, LC-MS/MS and GC-MS), bioaccessibility (standardized in vitro digestion model) and toxicological data (in vitro evaluation of cytotoxicity, genotoxicity and intestinal impact). A case study concerning Portuguese children exposure to patulin (PAT) and ochratoxin A (OTA), two mycotoxins co-occurring in processed cereal-based foods (PCBF) marketed in Portugal, was developed. Main results showed that there is low concern from a public health point of view relatively to PAT and OTA Portuguese children exposure through consumption of PCBF, considering the estimated daily intakes of these two mycotoxins (worst case scenarios, 22.930 ng/kg bw/day and 0.402 ng/kg bw/day, for PAT and OTA, respectively), their bioaccessibility and toxicology results. However, the present case study only concerns the risk associated with the consumption of PCBF and child diet include several other foods. The present work underlines the need to adopt a holistic approach for multiple mycotoxins risk assessment integrating data from exposure, bioacessibility and toxicity domains in order to contribute to a more accurate risk assessment.

Avaliação da toxicidade de florações naturais e de cultura de cianobactérias: efeitos sobre Ceriodaphnia silvestri (Crustacea, Cladocera)

The incidence of toxic cyanobacterial blooms is one of the important consequences of eutrophication in aquatic ecosystems. It is a very common phenomenon in reservoirs and shrimp ponds in the State of Rio Grande do Norte (RN), Brazil. Cyanobacterias produce toxins which can affect aquatic organisms and men trough the food chain. Aiming to contribute to the studies of cyanobacterias in RN, we propose: a) to evaluate the toxicity of isolated cyanobacterias in important fresh-water environments; and b) to verify the effects of both natural and cultured blooms occurred in reservoirs for human supply and in the cladoceran Ceriodaphnia silvestrii. This study was carried out using samples of natural blooms occurred between March and October of 2004 in Gargalheiras Dam (08º L e 39º W), in July of 2004 in Armando Ribeiro Gonçalves Dam (06o S e 37o W) and in commercial shrimp ponds (Litopenaeus vannamei) located in fresh-water environments. The samples were collected with plankton net (20µm.) for identification, isolation and obtaining of phytoplanktonic biomass for liophilization and later toxicity bioassays. The toxicity of cultured samples and natural blooms was investigated through bioassays in Swiss mice. Quantification of cyanobacteria in samples was conducted following the Ütermol method, with 300mL samples fixed with lugol. The toxicity test with Ceriodaphnia silvestrii followed ABNT, 2001 recommendations, and were accomplished with natural hepatotoxic bloom s samples and cultured samples of both non-toxic and neurotoxic C. raciborskii. In this test, five newborns, aged between 6 and 24 hours, were exposed to different concentrations (0 a 800 mg.L-1) of crude cyanobacterial extracts during 24 and 48 hours. Three replicates were used per treatment. The pH, temperature and dissolved oxygen at the beginning and after 24 and 48hours from the test were measured. We estimated the CL50 through the Trimmed Spearman-Karber method. The blooms were constituted by Microcystis panniformis, M. aeruginosa, Anabaena circinalis, Cylindrospermopsis raciborskii and Planktothrix agardhii, producers of mycrocistin-LR confirmed with HPLC analysis. Samples of hepatotoxic blooms registered toxinogenic potential for C. silvestrii, with CL50-24h value of 47.48 mg.L-1 and CL5048h of 38.15 mg.L-1 for GARG samples in march/2005; CL50-24h of 113,13 mg.L-1 and CL5048h of 88,24 mg.L-1 for ARG July/2004; CL50-24h of 300.39 mg.L-1 and CL50-48h of 149.89 mg.L-1 for GARG October/2005. For cultured samples, values of CL50-24h and CL50-48h for C. raciborskii toxic strains were 228.05 and 120.28 mg.L-1, respectively. There was no mortality of C. silvestrii during the tests with non-toxic C. raciborskii strain. The toxicity test with C. silvestrii presented good sensitivity degree to cyanotoxins. The toxicity of natural hepatotoxic blooms samples (microcystins) and cultured neurotoxic saxitoxins producer samples analyzed in this study give us strong indications of that toxin s influence on the zooplanktonic community structure in tropical aquatic environments. Eleven cyanobacteria strains were isolated, representing 6 species: Anabaenopsis sp., Cylindrospermopsis raciborskii, Chroococcus sp., Microcystis panniformis, Geitlerinema unigranulatum e Planktothrix agardhii. None presented toxicity in Swiss mice. The strains were catalogued and deposited in the Laboratório de Ecologia e Toxicologia de Organismos Aquáticos (LETMA), in UFRN, and will be utilized in ecotoxicológical and ecophysiological studies, aiming to clarify the causes and control of cyanobacterial blooms in aquatic environments in RN. This state s reservoirs must receive broader attention from the authorities, considering the constant blooms occurring in waters used for human consumption

Otimização e validação de metodologia analítica empregando SPE e LC-ESI-MS/MS para determinação de multiclasses de agrotóxicos e metabólitos em água de superfície e de abastecimento público

A aplicação de agrotóxicos nas práticas agrícolas aumentou muito nos últimos anos. Isto vem ocorrendo devido ao crescimento populacional, demandando maior produção de alimentos. O uso de agrotóxicos e seus resíduos tornaram-se um problema devido a possível contaminação das águas de superfície e subterrânea, podendo impactar o meio ambiente e causar danos à saúde pública. Na cidade de Rio Grande, RS, Brasil, o suprimento de água potável é realizado pela CORSAN (Companhia Riograndense de Saneamento), que capta a água do Canal São Gonçalo, o qual estabelece uma ligação entre as duas lagoas: Lagoa dos Patos e Lagoa Mirim. Em suas margens há também a captação de água para irrigação das culturas agrícolas. Esta interação entre o uso da água das lagoas e a agricultura, pode resultar na contaminação das águas que são captadas para abastecimento dos municípios situados na região. Uma metodologia analítica empregando Extração em Fase Sólida (SPE) e Cromatografia Líquida acoplada a uma fonte de ionização por Electrospray tandem Espectrometria de Massas (LCESI-MS/MS) foi desenvolvida e validada para a determinação de dezoito agrotóxicos multiclasses (herbicidas, inseticidas e fungicidas) e dois metabólitos em amostras de água superficial e de abastecimento público. Esta metodologia foi aplicada para monitoramento durante dez meses na água superficial do Canal São Gonçalo e na água de consumo da cidade de Rio Grande, após o tratamento pela CORSAN. Os agrotóxicos selecionados foram: clomazona, bispiribaque-sódio, diurom, atrazina, simazina, imazetapir, imazapique, metsulfuron-metílico, quincloraque, penoxsulam, 2,4-D, pirazosulfuron-etílico, bentazona, propanil, irgarol, tebuconazol, fipronil e carbofurano. Os metabólitos foram: 3,4-DCA e 3-hidroxicarbofurano. Os limites de detecção do método variaram entre 0,4 – 40,0 ng L -1 , enquanto para os limites de quantificação a variação foi de 4,0 – 100,0 ng L -1 . Todos os compostos apresentaram excelente linearidade, com coeficiente de determinação maior do que 0,99. As recuperações empregando SPE com cartuchos contendo 500 mg de C18ec, variaram entre 70 a 120%, para 95% dos compostos, apresentando %RSD 20%. Através do monitoramento de múltiplas reações (MRM), duas transições diferentes (íon precursor – íon produto) foram selecionadas para cada composto, uma para quantificação e outra para confirmação, o que aumentou a seletividade do método. Para as amostras analisadas, foram detectados agrotóxicos nível de ng L -1 . O método desenvolvido é sensível, rápido e apresenta elevada seletividade, permitindo a identificação e a quantificação dos agrotóxicos em águas superficiais e de abastecimento público, atendendo os níveis requeridos pelos órgãos reguladores como da União Européia (98/83/EC) e do Brasil segundo a Portaria Nº. 518 (25/03/2004).

The European Registered Toxicologist (ERT): Current status and prospects for advancement

Following its inception in 1994, the certification of European Registered Toxicologists (ERT) by EUROTOX has been recognized as ensuring professional competence as well as scientific integrity and credibility. Criteria and procedures for registration are contained in the ERT "Guidelines for Registration 2012". The register of ERT currently has over 1900 members. In order to continue the harmonisation of requirements and processes between national registering bodies as a prerequisite for official recognition of the ERT title as a standard, and to take account of recent developments in toxicology, an update of the ERT Guidelines has been prepared in a series of workshops by the EUROTOX subcommittees for education and registration, in consultation with representatives of national toxicology societies and registers. The update includes details of topics and learning outcomes for theoretical training, and how these can be assessed. The importance of continuing professional development as the cornerstone of re-registration is emphasised. To help with the process of harmonisation, it is necessary to collate and share best practices of registration conditions and procedures across Europe. Importantly, this information can also be used to audit compliance with the EUROTOX standards. As recognition of professionals in toxicology, including specialist qualifications, is becoming more important than ever, we believe that this can best be achieved based on the steps for harmonisation outlined here together with the proposed new Guidelines.

Are iron oxide nanoparticles safe? Current knowledge and future perspectives

Due to their unique physicochemical properties, including superparamagnetism, iron oxide nanoparticles (ION) have a number of interesting applications, especially in the biomedical field, that make them one of the most fascinating nanomaterials. They are used as contrast agents for magnetic resonance imaging, in targeted drug delivery, and for induced hyperthermia cancer treatments. Together with these valuable uses, concerns regarding the onset of unexpected adverse health effects following exposure have been also raised. Nevertheless, despite the numerous ION purposes being explored, currently available information on their potential toxicity is still scarce and controversial data have been reported. Although ION have traditionally been considered as biocompatible - mainly on the basis of viability tests results - influence of nanoparticle surface coating, size, or dose, and of other experimental factors such as treatment time or cell type, has been demonstrated to be important for ION in vitro toxicity manifestation. In vivo studies have shown distribution of ION to different tissues and organs, including brain after passing the blood-brain barrier; nevertheless results from acute toxicity, genotoxicity, immunotoxicity, neurotoxicity and reproductive toxicity investigations in different animal models do not provide a clear overview on ION safety yet, and epidemiological studies are almost inexistent. Much work has still to be done to fully understand how these nanomaterials interact with cellular systems and what, if any, potential adverse health consequences can derive from ION exposure.

Polycyclic aromatic hydrocarbons at fire stations: firefighters’ exposure monitoring and biomonitoring, and assessment of the contribution to total internal dose

This work characterizes levels of eighteen polycyclic aromatic hydrocarbons (PAHs) in the breathing air zone of firefighters during their regular work shift at eight Portuguese fire stations, and the firefighters' total internal dose by six urinary monohydroxyl metabolites (OH-PAHs). Total PAHs (ΣPAHs) concentrations varied widely (46.4-428ng/m(3)), mainly due to site specificity (urban/rural) and characteristics (age and layout) of buildings. Airborne PAHs with 2-3 rings were the most abundant (63.9-95.7% ΣPAHs). Similarly, urinary 1-hydroxynaphthalene and 1-hydroxyacenaphthene were the predominant metabolites (66-96% ΣOH-PAHs). Naphthalene contributed the most to carcinogenic ΣPAHs (39.4-78.1%) in majority of firehouses; benzo[a]pyrene, the marker of carcinogenic PAHs, accounted with 1.5-10%. Statistically positive significant correlations (r≥0.733, p≤0.025) were observed between ΣPAHs and urinary ΣOH-PAHs for firefighters of four fire stations suggesting that, at these sites, indoor air was their major exposure source of PAHs. Firefighter's personal exposure to PAHs at Portuguese fire stations were well below the existent occupational exposure limits. Also, the quantified concentrations of post-shift urinary 1-hydroxypyrene in all firefighters were clearly lower than the benchmark level (0.5μmol/mol) recommended by the American Conference of Governmental Industrial Hygienists.

Effects of physical exercise training in DNA damage and repair activity in humans with different genetic polymorphisms ofhOGG1(Ser326Cys)

The main purpose of this pilot study was to investigate the possible influence of genetic polymorphisms of the hOGG1 (Ser326Cys) gene in DNA damage and repair activity by 8-oxoguanine DNA glycosylase 1 (OGG1 enzyme) in response to 16 weeks of combined physical exercise training. Thirty-two healthy Caucasian men (40-74 years old) were enrolled in this study. All the subjects were submitted to a training of 16 weeks of combined physical exercise. The subjects with Ser/Ser genotype were considered as wild-type group (WTG), and Ser/Cys and Cys/Cys genotype were analysed together as mutant group (MG). We used comet assay in conjunction with formamidopyrimidine DNA glycoslyase (FPG) to analyse both strand breaks and FPG-sensitive sites. DNA repair activity were also analysed with the comet assay technique. Our results showed no differences between DNA damage (both strand breaks and FPG-sensitive sites) and repair activity (OGG1) between genotype groups (in the pre-training condition). Regarding the possible influence of genotype in the response to 16 weeks of physical exercise training, the results revealed a decrease in DNA strand breaks in both groups, a decrease in FPG-sensitive sites and an increase in total antioxidant capacity in the WTG, but no changes were found in MG. No significant changes in DNA repair activity was observed in both genotype groups with physical exercise training. This preliminary study suggests the possibility of different responses in DNA damage to the physical exercise training, considering the hOGG1 Ser326Cys polymorphism.

Atividade bioinseticida e mecanismo de ação de vicilinas de sementes Erythrina velutina sobre moscas-das frutas Ceratitis capitata

The fruit fly Ceratitis capitata is considered the most destructive pest of the world fruitculture. Many pest management practices, mainly based on agrochemicals, have been developed to allow the world-wide commerce of fruit. Solutions to decrease the use of synthetic insecticides in agriculture are based on the development of new target-specific compounds which cause less damage to the environment, especially vegetal proteins with insecticidal effects. The aim of this work was to evaluate the deleterious effect of a purified vicilin of E. velutina (EvV) seeds to C. capitata larvae and adult insects and to investigate the mechanisms involved in these effects. EvV was purified, characterized and its deleterious effect was tested in bioassay systems. EvV mechanism of action was determined by immunodetection techniques and fluorescence localization in chitin structures that are present in C. capitata digestory system. EvV is a glycoprotein with affinity to chitin. Its molecular weight, of 216,57 kDa, was determined by gel filtration chromatography in FPLC system. Using SDS-PAGE, it was possible to observe EvV dissociation in two main subunits of 54,8 and 50,8 kDa. When it was submitted to eletrophoresis in native conditions, EvV presented only one band of acid characteristic. The WD50 and LD50 values found in the bioassays were 0,13% and 0,14% (w/w), respectively for the larvae. EvV deleterious effects were related to the binding to chitin structures presented in peritrophic membrane and gut epithelial cells, associated with its low digestibility in C. capitata digestive tract. The results described herein are the first demonstration of the larvicidal effects of plant protein on C. capitata larvae. EvV may be part of the pest management programs, in the toxic bait composition, or an alternative in plant improvement program