Browsing by Issue Date, starting with "2020-11-18"
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- earlyMYCO: assessing the risk associated to early-life exposure to mycotoxinsPublication . Assunção, Ricardo; Alvito, Paula; Ferreira, M.; Bastos, P.; Nunes, C.; De Boevre, Marthe; Duarte, E.; Nunes, B.; Namorado, S.; Silva, S.; Pires, S.; Martins, CarlaA number of health disorders has been associated to exposure to hazardous chemicals during the first 1000 days of life. Therefore, a proper risk assessment built on accurate data assumes particular im-portance to evaluate the potential impact that early-life exposure could represent in adulthood. Mycotox-ins are secondary fungal metabolites that might cause harmful effects in humans and animals. Recent studies showed that Portuguese young children are exposed to multiple mycotoxins through food con-sumption which could constitute a health concern. However, earlier exposure to these compounds re-mains unexplored. earlyMYCO – Early-life exposure to MYCOtoxins and its impact on health, a national funded project, intends to contribute to clarify this issue evaluating the health effects of early-life exposure of Portuguese mother-and-child pairs to mycotoxins and assessing the associated risk. The Estimated Daily Intake, using human biomonitoring data, will be compared with reference dose values. For those mycotoxins representing a health concern, an estimate of the associated probable health-impact will be performed by calculating the associated burden in terms of disability-adjusted life years (DALY). Preliminary results of exposure to mycotoxins through food consumption (cereal-based foods) in young children (≤ 3 years old) revealed a potential adverse health effect for percentiles of intake of aflatoxins above or equal to P50 (corresponding to 0.041 ng/kg body weight/day or higher). Our results will contribute to reach an accurate risk assessment framework and to establish and prioritize preventive measures to reduce exposure to chemicals, especially for vulnerable population groups as pregnant women and infants.
- Biomonitoring of occupational exposure to a known carcinogen: formaldehydePublication . Costa, Solange; Costa, Carla; Madureira, Joana; Valdiglesias, Vanessa; Teixeira- Gomes, Armanda; Laffon, Blanca; Teixeira, João PauloThe aim of the present study was to evaluate the occupational exposure to FA (n = 85) relating the exposure with different biomarkers and individual susceptibility, a control group (n = 87) was also evaluated. Genotoxicity was assessed by means of cytogenetic alterations and DNA damage, by comet assay (%TDNA)
- In vitro combined toxicity of chromium, nickel and PAHS in human lung cells as support for mixtures risk assessmentPublication . Alves, Inês; Ladeira, Carina; Tavares, Ana M.; Viegas, Susana; Louro, Henriqueta; Silva, Maria JoãoRisk assessment of chemicals mainly relies on exposure to single chemicals and their hazardous effects, although the real scenario in occupational settings is more commonly characterized by exposure to chemi-cal mixtures. Chromium (Cr), Nickel (Ni), and Polycyclic Aromatic Hydrocarbons (PAHs) are often pre-sent in occupational settings, such as aeronautic industries, where workers are exposed primarily through inhalation. Considering that those substances are recognized lung carcinogens acting mainly by genotoxic mechanisms, it is likely that interactive effects occur, indicating that the risk from occupational exposure to these chemicals should be assessed as a mixture. Such issue is being addressed in the HBM4EU Initiati-ve, where a real scenario of occupational exposure has been studied. In order to provide support to the hazard assessment of the referred mixture, the present work aimed to evaluate the combined toxicity of Cr(VI), Ni, and benzo(a)pyrene (BaP), using a human lung cell line (A549 cells). MTT assay was performed for each individual chemical and a dose-response curve was esta-blished, enabling the determination of the IC50. The combined toxicity of the Cr and Ni mixture as well as that of Cr, Ni and BaP were determined comparatively to the single chemicals’ toxicity to ascertain whet-her additive effects or deviations from additivity towards synergism or antagonism was obtained. The results will be presented and discussed and are expected to contribute to the overall mixture’s risk asses-sment.
- Biomarker-validated maternal smoking and environmental tobacco smoke exposure status and its associations with perinatal outcomesPublication . Silva, Ana Inês; Camelo, Alexandra; Madureira, Joana; Reis, Ana Teresa; Barbosa, Fernando; Teixeira, João Paulo; Costa, CarlaTobacco consumption and environmental tobacco smoke (ETS) are associated with an increased risk of multiple adverse perinatal outcomes. Within the framework of the NEOGENE project, the aim of this study was to validate smoking and ETS exposure status among pregnant women, to more precisely ascertain its associations with perinatal outcomes, using urinary cotinine (UC), a biomarker of tobacco smoke exposure. (...)
- Air pollution in urban environments: implications for citizens´healthPublication . Slezakova, Klara; Madureira, Joana; Teixeira, João Paulo; Pereira, Maria do CarmoCurrently, 54% of worldwide population lives in urban areas. While growing urbanization causes environmental pollution and energy demand, it has also adverse implications on health, living conditions and lifestyle habits of the respective citizens. To protect human health, numerous organizations have implemented guidelines to limit environmental pollution, or even proposed recommendation on human activity, but how do these translate to the exposure and risks of the respective population? This work aimed to explore how urban development, using time series data from 2015 to 2018, might influence air quality and potential health risks of citizens living in these zones.
- Anchoring HBM4EU data to chemicals risk assessmentPublication . Silva, Maria JoãoA major goal of the European Human Biomonitoring Initiative, HBM4EU, is to coordinate and advance human biomonitoring across Europe and reinforce its application in different regulatory frameworks for chemicals. To illustrate the development of state-of-the-art approaches and the potential of human biomonitoring (HBM) data to refine exposure assessment and, thereby, risk assessment, this presentation will be focused on the work carried out on hexavalent chromium, [Cr(VI)], an important occupational lung carcinogen, which is currently authorized in Europe for several industrial activities. Cr(VI) was considered a priority substance under the HBM4EU Project, indicating the need for generating and analyzing data on human exposure, despite the recently agreed binding limit value for occupational exposure established in the Eu-ropean Union. The anchoring of HBM to risk assessment and management practices will be evidenced through the infor-mation generated from three different studies, namely: i) a critical review on effect biomarkers to link Cr(VI) exposure to health outcomes, ii) a multinational, collaborative study to support management of oc-cupational exposure to Cr(VI), and iii) the development of a case study on co-exposure to Cr (VI), nickel and polycyclic aromatic hydrocarbons, to advance the identification of mixture health effects and to pro-gress towards a more refined risk assessment. These research efforts to integrate HBM into new risk assessment approaches need to be supported by mechanistic knowledge obtained from in vitro/in vivo studies, toxicokinetic data and the development of adverse outcome pathways, as well.
- Risk assessment of combined occupational exposure to hexavalent chromium, nickel, and PAHs: a literature-based approachPublication . Tavares, Ana Maria; Viegas, Susana; Louro, Henriqueta; Silva, Maria JoãoOccupational exposure is usually characterized by a complex mixture of chemicals, originating from different raw materials and transformation processes. Co-exposure to hexavalent chromium (Cr(VI)), nickel (Ni) and polycyclic aromatic hydrocarbons (PAHs) can occur in some workplaces. These substances display well-known genotoxic and carcinogenic effects, especially in the respiratory tract, sharing similar modes of action. However, reference values for occupational exposure only account for individual components exposure and not for a potential mixture effect. In the scope of HBM4EU Initiative, we performed a mixtures risk assessment (MRA) based on literature from occupational studies conducted in the European Union that contain human biomonitoring (HBM) data on Cr(VI), Ni and/or PAHs. After HBM data extraction, Hazard Quotient (HQ) and Hazard Index (HI) were calculated for binary and tertiary mixtures. Exposure was considered of concern if HI>1. Twenty-four articles were selected, most (n=18, 75%) presenting Cr(VI) and Ni exposure biomarkers. Among these, HI>1 was obtained for all studies on welding activities, in which chromium was the main driver of toxicity with HQ>1 in most measurements. Only two studies in waste incineration setting reported exposure to the three substances, and again all HI>1. Noteworthy, for some of the analysed studies, although exposure levels were below the reference values, still the mixture was considered of concern (HI>1). Our findings show the limitations of applying occupational exposure reference values defined on a single substance basis to workplaces, highlighting the relevance of MRA as a more realistic approach to provide more suitable risk management measures in occupational settings.