Percorrer por autor "Morais, S."
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- Biomonitoring of wildfire emissions exposure among firefighters during active fire missionsPublication . Barros, B.; Paiva, A.M.; Azevedo, R.; Alves, Sara Elisa Brás;; Esteves, F.; Fernandes, Adília; Vaz, Josiana A.; Slezakova, K.; Pereira, M.C.; Costa, S.; Almeida, A.; Teixeira, J. P.; Oliveira, M.; Morais, S.The aim of this study was to conduct a multidisciplinary biomonitoring assessment of the exposure and health impacts of wildfire emissions on firefighters from the Northern Portugal, one of the regions most affected by wildfires. Firefighters from fourteen fire stations participated in pre- and post-exposure sampling campaigns during two consecutive years. Self-reporting biometric characteristics, lifestyle, clinical information, career years, environmental/occupational exposure along with urinary biomarkers of polycyclic aromatic hydrocarbons metabolites (OHPAHs), metal(loid)s [from the priority pollutant lists compiled by the Agency for Toxic Substances and Disease Registry 14, United States Environmental Protection Agency 11, and the Human Biomonitoring for Europe Initiative priority 4], lung injury, lipid peroxidation, DNA damage, blood pressure, cardiac frequency, and hemogram were evaluated (Barros et al., 2025; Esteves et al., 2025; Paiva et al., 2024a; Paiva et al., 2024b). Stronger correlations were found between OHPAHs and metal(loid) levels and effect biomarkers after wildfire combat in comparison to pre-exposure. Wildfire exposure increased urinary -smokers. For the latter, copper, cadmium and barium ions correlated with lung injury; antimony and cadmium correlated with lipid peroxidation; DNA oxidation correlated with antimony, cadmium, copper, lead, zinc, selenium, and rubidium levels. Moreover, arsenic, antimony, lead, and copper induced lipid peroxidation, and lead was linked with DNA oxidation among wildfire-exposed smokers. Significant positive correlations were found for age and/or career length with cadmium, lead, barium, strontium, and mercury, and for body mass index with arsenic. These results point to an increased risk of health effects both in non-smoking and smoking firefighters because of their occupation, highlighting the necessity to strengthen prevention strategies.
- In vitro biomineralization by osteoblast-like cells : Part II - characterisation of cellular culture supernatantsPublication . Morais, S.; Carvalho, Graça S. de; Faria, Joaquim; Gomes, Helder; Sousa, JoãoThe quantification of total calcium, phosphorus, iron, chromium and nickel in cell culture medium by electrochemical or spectroscopic means may require digestion of samples. Nevertheless, when pH adjustment is performed for values higher than about 6.5, the formation of two phases occurs: a white precipitate and a clear solution. Analysing both phases using microelectrodes, atomic absorption spectrometry (AAS), diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, X-ray dispersive (XRD) analysis, scanning electron microscopy (SEM) and energy dispersive spectroscopic (EDS) analysis, it was observed that iron, chromium and nickel are not co-precipitating with the white solid phase. If quantification of calcium, phosphorus and magnesium is intended, a ten-fold dilution at least, must be performed to avoid most of these elements going into the precipitate. This knowledge is crucial if a mineralization study is going to be made.
- Monitoring of ochratoxin a exposure of the Portuguese population through a nationwide urine survey – Winter 2007Publication . Duarte, S.C.; Bento, J.M.V.; Pena, A.; Lino, C.M.; Delerue-Matos, Cristina; Oliva-Teles, T.; Morais, S.; Correia, Manuela; Oliveira, Beatriz; Alves, M. Rui; Pereira, J.A.Ochratoxin A (OTA) is a mycotoxin produced by a variety of fungi, such as Penicillium verrucosum and Aspergillium spp., which has been found to have a wide number of potentially deadly toxic effects, and can enter the human organism through a variety of means. It then finds its way into the bloodstream and, after a lengthy process, is eventually excreted through the urine. It can thus be detected in its original form not only in blood samples but also in this biological medium. As such, and in an attempt to evaluate the exposure of the Portuguese population to this mycotoxin, morning urine samples were collected during the Winter of 2007, from each of five geographically distinct Portuguese locations — Bragança, Porto, Coimbra, Alentejo, and Algarve — and subjected to extraction by immunoaffinity columns and to OTA quantification through liquid chromatography coupled with fluorescence detection. Prevalent incidence was higher than 95% with Coimbra being the exception (incidence of 73.3%). In nearly all locations, the OTA content of most samples was found to be above the limit of quantification (LOQ) of 0.008 ng/ml. Indeed, excluding Coimbra, with an OTA content level of 0.014 ng/ml, all regions featured content values over 0.021 ng/ml.
- Ochratoxin A contamination of bread – Portugal nationwide survey during winter 2007/2008.Publication . Duarte, S.C.; Bento, J.M.V.; Pena, A.; Lino, C.M.; Pereira, J.A.; Delerue-Matos, Cristina; Oliva-Teles, T.; Morais, S.; Correia, Manuela; Oliveira, BeatrizOchratoxin A (OTA) remains one of the most important mycotoxins known, due to its ubiquitous occurrence, wide range of susceptible food commodities and observed toxic effects, in both animals and humans. The reported toxic effects include carcinogenic, nephrotoxic, teratogenic, neurotoxic and immunotoxic.
- Ochratoxin A content in urine from Bragança and Alentejo: a compartive analysis (Winter 2007).Publication . Duarte, S.C.; Bento, J.M.V.; Pena, A.; Lino, C.M.; Pereira, J.A.; Delerue-Matos, Cristina; Oliva-Teles, T.; Morais, S.; Correia, Manuela; Oliveira, BeatrizOchratoxin A (OTA) is a mycotoxin which possesses a variety of toxic effects, including enzyme inhibition, immunosuppression, teratogenicity, nephrotoxicity, and carcinogenicity. It is produced by fungi for which foodstuffs such as beans, cereals, fruits, and seeds constitute an ideal growing media. It has proven itself at least partly resistant to food processing methods, meaning it is also present in derived products and thus finds its way into the human organism. Recent studies have suggested that, though OTA can be found in both plasma and urine – through which it is eliminated, though with great difficulty – the latter provides a better indication of OTA ingestion. Its collection procedure is also less invasive, and developments in analytical methodology allow an equally precise analysis.