Percorrer por autor "Pereira, M.J."
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- Interlaboratory Validation of the Cell Transformation Assay (CTA) for Carcinogenic Assessment of BPA AlternativesPublication . El Yamani, N.; Aimonen, K.; Dusinska, M.; Guichard, Y.; Honza, T.; Louro, H.; Pereira, M.J.; Rundén-Pran, E.; SenGupta, T.; Tavares, A.M.; Silva, M.J.Bisphenol A (BPA) has long been used in various plastic products, resins and coatings, making human exposure to this chemical inevitable. Due to its harmful health effects, including endocrine disruption, and immunotoxicity, BPA has been increasingly replaced by several alternative compounds. However, there are still significant gaps in research regarding the safety of these BPA alternatives, particularly concerning their potential carcinogenicity. One of the in vitro assays to assess carcinogenic potential of chemicals is the Bhas-42 cell transformation assay (CTA). The assay can detect both genotoxic and non-genotoxic carcinogens It is valuable in identifying potential cancer risks before widespread exposure occurs, contributing to the development of safer chemicals and products, as well as better regulatory standards while adhering to the 3R concept. The EU-Partnership for the Assessment of Risks from Chemicals (PARC) project is addressing these research gaps to enhance the risk assessment of BPA alternatives. BPA and some alternatives, including BPZ, BPE, BPAP, BPA-MAE, BPP, and TCBPA, were selected for evaluation of their carcinogenic potential using the in vitro 2-stage Bhas-42 CTA. A key objective of the project is to validate the CTA as a reliable in vitro method for assessing carcinogenicity. To ensure consistency and accuracy across participating labs, an interlaboratory comparison was initiated and a standardized SOP was developed, including concentration ranges for controls and BPA analogues, in alignment with OECD guidance document. The first results from the protocol harmonization, using the selected controls, were consistent across all participating labs. BPA and its analogues are being tested, and the results are under evaluation. The data generated will contribute to the overall weight of evidence on the hazards posed by these chemicals and, when combined with findings from other endpoints, will provide a solid basis for refining their regulation.
- A study protocol to evaluate the relationship between outdoor air pollution and pregnancy outcomesPublication . Ribeiro, M.C.; Pereira, M.J.; Soares, A.; Branquinho, C.; Augusto, S.; Llop, E.; Fonseca, S.; Nave, J.G.; Tavares, A.B.; Dias, Carlos Matias; Silva, A.; Selemane, I.; De Toro, J.; Santos, M.J.; Santos, F.Background - The present study protocol is designed to assess the relationship between outdoor air pollution and low birth weight and preterm births outcomes performing a semi-ecological analysis. Semi-ecological design studies are widely used to assess effects of air pollution in humans. In this type of analysis, health outcomes and covariates are measured in individuals and exposure assignments are usually based on air quality monitor stations. Therefore, estimating individual exposures are one of the major challenges when investigating these relationships with a semi-ecologic design. Methods/Design Semi-ecologic study consisting of a retrospective cohort study with ecologic assignment of exposure is applied. Health outcomes and covariates are collected at Primary Health Care Center. Data from pregnant registry, clinical record and specific questionnaire administered orally to the mothers of children born in period 2007-2010 in Portuguese Alentejo Litoral region, are collected by the research team. Outdoor air pollution data are collected with a lichen diversity biomonitoring program, and individual pregnancy exposures are assessed with spatial geostatistical simulation, which provides the basis for uncertainty analysis of individual exposures. Awareness of outdoor air pollution uncertainty will improve validity of individual exposures assignments for further statistical analysis with multivariate regression models. Discussion Exposure misclassification is an issue of concern in semi-ecological design. In this study, personal exposures are assigned to each pregnant using geocoded addresses data. A stochastic simulation method is applied to lichen diversity values index measured at biomonitoring survey locations, in order to assess spatial uncertainty of lichen diversity value index at each geocoded address. These methods assume a model for spatial autocorrelation of exposure and provide a distribution of exposures in each study location. We believe that variability of simulated exposure values at geocoded addresses will improve knowledge on variability of exposures, improving therefore validity of individual exposures to input in posterior statistical analysis.