Browsing by Author "Pinto, M."
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- Airborne bacteria and fungi in different indoor environments: levels and dose ratesPublication . Paciência, I.; Madureira, J.; Cavaleiro Rufo, J.; Aguiar, L.; Teixeira, João Paulo; Pinto, M.; Moreira, A.; de Oliveira Fernandes, E.The study aimed to: (i) quantify bacteria and fungi concentrations in 4 indoor environments; (ii) identify the recovered fungi; (iii) assess the impact of outdoor bacteria and fungi indoors; and (iv) estimate bacterial and fungal inhalation dose rates in children and elderly. Air samples were collected from 20 primary schools, 68 homes, 9 child day-care centres and 22 elderly care centres, with a microbiological air sampler using TSA and MEA culture media.
- Assessment of ecologic and human health risks from a contaminated estuarine environmentPublication . Silva, M.J.; Pinto, M.; Caeiro, S.Due to their particular geographic characteristics, estuaries are often used for diverse human and industrial activities that may generate and release potentially harmful chemical contaminants. Thus, estuaries may be reservoirs of a wide variety of chemicals, including mutagenic and carcinogenic ones (e.g., metals, polycyclic aromatic hydrocarbons and pesticides), particularly when considering the potential for aquatic sediments to accumulate and continuously re-suspend contaminants into the water column. Importantly, besides being available to the local biota, the proximity/use of these contaminated sites might also be unsafe to the local population, provided that they are directly exposed (e.g. fishing, agricultural or recreational activities) or indirectly, through their diet. This work was focused on the river Sado Estuary, where the northern banks include urban areas and a heavy-industry park while the southern banks are mainly impacted by extensive agriculture activities. Sizable amounts of hazardous contaminants (e.g., metals, pesticides and polycyclic aromatic hydrocarbons) were identified in the estuarine sediments raising concern to the local populations because estuarine organisms and locally produced vegetables constitute the basis of their diet. The study intended to assess the adverse effects of estuary contaminants on human and ecosystem health through an integrative methodology based on several lines of evidence. An epidemiological survey was conducted to assess the exposure of a local population to the estuary environment as well as their health status. Furthermore, analyses of sediments, soil and wells water contamination were performed. Biological effects were assessed in major estuarine species with commercial value (clams, sole and cuttlefish); the cytotoxic and genotoxic potential of sediments were characterized in a human cell line. The results showed that the sediments’ contaminants were capable of inducing concentration-dependent cytotoxic and genotoxic damage in vitro and also allowed the distinction between two ecogeographical areas (urban/industrial and rural) with respect to type and intensity of the genetic damage, likely reflecting different patterns of toxicants mixtures. The integration of data from all study components indicated that the estuary is moderately impacted by complex mixtures of toxicants, affecting the aquatic biota and potentially able of inducing adverse effects on human cells. Although no clear evidence of contaminant-related adverse health effects in the studied population was found, the dose-related genotoxicity observed in the in vitro approach together with the evidences of direct and indirect human exposure indicates that those toxicants might constitute a risk factor to the development of chronic-degenerative diseases.
- Drinking water contaminants: toxicity of halogenated polycyclic aromatic hydrocarbonsPublication . José, S.S.; Pinto, M.; Antunes, A.M.M.; Louro, H.; Jordão, Luísa; Silva, M.J.; Cardoso, A.S.Food may be contaminated with polycyclic aromatic hydrocarbons (PAHs) in the process of smoking or heating. These contaminants or their derivatives can also be present in drinking water when raw water contacts with discharges of untreated industrial/waste water effluents, forest fires or by solubilisation of organic material from contaminated soils. A few studies have shown that water disinfection can lead to halogenated derivatives of PAHs (HPAHs) as chlorinated and brominated derivatives, and there are evidences that these compounds may have greater mutagenicity than the parent PAHs. In this study the cytotoxic and genotoxic effects of chlorinated/brominated derivatives of pyrene (Pyr) and benzo[a]anthracene (BaA), 1-ClPyr, 1-BrPyr and 7-ClBaA, which can be formed as water disinfection by-products, were studied in HepG2 cells to assess their potential hazard to human health. The formation of 1-ClPyr, 1-BrPyr and 7-ClBaA under aqueous disinfection conditions in waters contaminated with Pyr and BaA, was confirmed with an optimized gas chromatography method. Cells exposed (24h) to several concentrations of BaA and 7-ClBaA (1 to 200μM) displayed a dose-related and significant increase of cytotoxicity (neutral red assay) with IC50 values of 3.37 and 12.63µM respectively. For Pyr, 1-ClPyr and 1-BrPyr (10 to 200μM), a lower but significant dose-related cytotoxicity was observed. At non-cytotoxic concentrations (10 and 15µM), 7-ClBaA was able to induce a significantly higher level of oxidative DNA damage in HepG2 cells than its parent compound, as assessed by the FPG-modified comet assay. Under these conditions neither Pyr nor its derivatives were genotoxic. In conclusion, the disinfection process may give rise to genotoxic HPAHs with potential impact on human health and it should be performed in raw waters with minimal content of total organic carbon. In real conditions, humans may be exposed to a mixture of these organic compounds and thus their combined toxic effects should be further evaluated.
- Exposure to emissions from cleaning products in primary schools: a test chamber studyPublication . Cavaleiro Rufo, João; Madureira, J.; Paciência, I.; Sousa, J.; Oliveira Fernandes, E.; Slezakova, K.; Pereira, M.C.; Aguiar, L.; Teixeira, J.P.; Pinto, M.; Delgado, L.; Moreira, A.The aim of this study was to investigate volatile organic compound (VOC) emissions from floor cleaning products (FCPs) used in primary schools and compare them with emissions from a previously recognised low-emitting product (control sample). Samples of FCPs used in 3 primary schools and a control sample were collected and subsequently examined in a test chamber. Measurements were performed at t = 0, 60, 120, 240 and 480 min after application. The analysis was performed by GC-MS. The results showed that VOC emissions were higher during t = 0 than in the subsequent measurements, with the exception of benzaldehyde and benzene, being significant for toluene and m/p-xylene. VOC emissions from the control FCP were not significantly lower than the schools FCPs. To prevent the exposure of children to VOCs, the school cleaning should be performed at the end of the classes.
- Formation of Emerging Disinfection Byproducts in Water and Evaluation of Potential Genotoxic Effects: the Case of Chlorinated Polycyclic Aromatic HydrocarbonsPublication . Rebola, M.; Pinto, M.; Louro, H.; Antunes, A.M.M.; José, S.S.; Rocha, M.R.; Silva, M.J.; Cardoso, A. S.Disinfection byproducts (DBPs) are formed when disinfectants used in water treatment plants (WTPs) react with natural (or anthropogenic) organic matter present in the source water. Many studies have addressed health risks posed by a life-time exposure to DBPs through chlorinated drinking water or through dermal or inhalation exposure routes. Experimental studies have revealed genotoxic and carcinogenic effects of some DBPs and epidemiological studies evidenced potential associations between chlorinated drinking water and bladder or colorectal cancer. In addition, a possible link between chlorinated drinking water and reproductive/developmental effects has been hypothesized. Many DBPs have been identified in treated water, which justifies the growing concern about the potential health effects of emerging unregulated DBPs, some of which appear to be more genotoxic, in some assays, than the regulated DBPs. Polycyclic aromatic hydrocarbons (PAHs) are among the most persistent contaminants detected in environmental samples such as river sediments and tap water. Water chlorination can lead to the formation of chlorinated derivatives of PAHs (Cl-PAHs) and the few available toxicological studies have shown that Cl-PAHs possess greater mutagenicity than the corresponding parent PAHs. The present study had two main objectives: 1) identification of the major chlorinated derivatives of benzo[a]pyrene (BaP) and fluoranthene (Fluo) formed as chlorination by-products and 2) evaluation of their potential hazard to humans, through the characterization of their potential genotoxic effects in a human cell line. To synthesize chlorinated standards of PAHs, a newly two phase (water/n-hexane) method was developed for BaP and Fluo. 6-Cl-BaP was obtained as the major chlorination product of BaP, and 3-Cl-Fluo and 1,3-Cl2-Fluo of Fluo. The formation of these BaP and Fluo chlorinated derivatives was also observed under WTPs chlorination conditions after at 0.5 until 24 h of exposure. The effects of equimolar concentrations of 6-Cl-BaP vs. BaP and of 3-Cl-Fluo/1,3-Cl2-Fluo vs. Fluo on cell viability and DNA integrity were assessed by the neutral red uptake (NR) and the comet assay, respectively. Exposure of HepG2 cells to a dose-range of 6-Cl-BaP and BaP showed that both compounds are cytotoxic above 50 μM and that, at the equimolar doses of 100 and 125 μM, 6-Cl-BaP is able to induce a significantly higher level of DNA damage than BaP. On the other hand, no changes of cell viability were observed after exposure to several concentrations of Fluo and its derivatives. Likewise, none of the compounds was able to significantly induce DNA damage. In conclusion, the present data confirmed that chlorinated derivatives of BaP and Fluo are formed during WTPs chlorination procedures and allowed the identification of their major chlorinated derivatives that should be further analysed in drinking water. On the other hand, the results from the comet assay evidenced a higher DNA damaging effect of Cl-BaP comparatively to its parent compound, suggestive of a more potent genotoxic effect. In spite of the negative results found for Fluo and its chorinated products, further genotoxicity studies are still needed to allow a definite conclusion. Although health risks of DBPs are small compared to health risks of waterborne diseases, the identification of hazardous Cl-PAHs in water emphasizes the need of development of new and safer water disinfection methods.
- Formation of emerging disinfection byproducts in water and evaluation of potential genotoxic effects: the case of halogenated polycyclic aromatic hydrocarbonsPublication . Pinto, M.; Antunes, A.M.M.; José, S.S.; Alves, A.C.; Louro, H.; Silva, M.J.; Cardoso, A.S.Disinfection byproducts (DBPs) are formed when disinfectants used in water treatment plants (WTPs) react with natural (or anthropogenic) organic matter present in the source water. Many studies have addressed health risks posed by a life-time exposure to DBPs through chlorinated drinking water or through dermal or inhalation exposure routes. Experimental studies have revealed genotoxic and carcinogenic effects of some DBPs and epidemiological studies evidenced potential associations between chlorinated drinking water and bladder or colorectal cancer. In addition, a possible link between chlorinated drinking water and reproductive/developmental effects has been hypothesized. Many DBPs have been identified in chlorinated water, which justifies the growing concern about the potential health effects of emerging unregulated DBPs, some of which appear to be more genotoxic, in some assays, than the regulated DBPs. Polycyclic aromatic hydrocarbons (PAHs) are among the most persistent contaminants detected in environmental samples such as river sediments and tap water. A few studies have already proven that water disinfection can lead to the formation of halogenated derivatives of PAHs, such as chlorinated (Cl-PAHs) and brominated PAHs (Br-PAHs). The available toxicological studies have shown that these compounds possess, in general, greater mutagenicity than the corresponding parent PAHs. Our investigation group have also showed that exposure of HepG2 cells to a dose-range of 6-Cl-benzo[a]pyrene (6-Cl-BaP) and BaP resulted in cytotoxicity above 50 µM and that, at the equimolar doses of 100 and 125 µM, 6-Cl-BaP was able to induce a significantly higher level of DNA damage than BaP. The present study had two main objectives: 1) identification of the major chlorinated and brominated derivatives of benzo[a]anthracene (BaA) and pyrene (Pyr) formed as disinfection by-products and 2) evaluation of their potential hazard to humans, through the characterization of their potential cytotoxic and genotoxic effects in a human cell line. To synthesize Cl-PAHs and Br-PAHs the method of Mitchell was developed for BaA and Pyr. 1-Cl-Pyr and 1-Br-Pyr were obtained as the major chlorinated and brominated derivatives of Pyr, and 7-Cl-BaA and 7-Br-BaA as the reaction products of BaA. Cell viability and DNA integrity of those derivatives were assessed by the neutral red uptake (NR) and the comet assay, respectively, allowing the comparison of their genotoxic potential. Although health risks of DBPs are small compared to the health risks of waterborne diseases, the formation of hazardous halogenated-PAHs in chlorinated water water emphasizes the need of development of new and safer water disinfection methods.
- Halogenated polycyclic aromatic hydrocarbons associated with drinking water disinfectionPublication . José, S. S.; Pinto, M.; Antunes, A.M.M.; Louro, H.; Silva, M.J.; Cardoso, A.S.Introduction: Disinfection by-products (DBPs) have been identified in chlorinated water. This fact justifies the growing concern about the potential health effects of emerging unregulated DBPs, some of which appear to be more genotoxic than the regulated DBPs[1]. Polycyclic aromatic hydrocarbons (PAHs) are among the most persistent contaminants detected in environmental samples such as river sediments and tap water. A few studies have already proven that water disinfection can lead to the formation of halogenated derivatives of PAHs, such as chlorinated and brominated PAHs[2] . The available toxicological studies have shown that these compounds possess, in general, greater mutagenicity than the corresponding parent PAHs. Our research group has also shown that exposure of HepG2 cells to a dose-range of 6-Cl-benzo[a]pyrene (6-ClBaP) and BaP resulted in cytotoxicity above 50 µM and that, at the equimolar doses of 100 and 125 µM, 6-ClBaP was able to induce a significantly higher level of DNA damage than BaP[3] . The present study had two main objectives: 1) identification of the major chlorinated and brominated derivatives of benzo[a]anthracene (BaA) and pyrene (Pyr) formed as disinfection by-products and 2) evaluation of their potential hazard to humans, through the characterization of their potential cytotoxic and genotoxic effects in a human cell line.
- How indoor air quality changed in primary schools: a 4 years follow-up studyPublication . Cavaleiro Rufo, J.; Madureira, J.; Paciência, I.; Aguiar, L.; Teixeira, J.P.; Slezakova, K.; do Carmo Pereira, M.; Pinto, M.; Moreira, A.; de Oliveira Fernandes, E.The aim of this study was to assess if IAQ in primary schools improved in 4 years as a result of adopting the SINPHONIE guideline-based recommendations.
- Insights into the population structure and pan-genome of Haemophilus influenzaePublication . Pinto, M.; González-Díaz, A.; Machado, M.P.; Duarte, S.; Vieira, L.; Carriço, J.A.; Marti, S.; Bajanca-Lavado, M.P.; Gomes, J.P.The human-restricted bacterium Haemophilus influenzae is responsible for respiratory infections in both children and adults. While colonization begins in the upper airways, it can spread throughout the respiratory tract potentially leading to invasive infections. Although the spread of H. influenzae serotype b (Hib) has been prevented by vaccination, the emergence of infections by other serotypes as well as by non-typeable isolates (NTHi) have been observed, prompting the need for novel prevention strategies. Here, we aimed to study the population structure of H. influenzae and to get some insights into its pan-genome. We studied 305H. influenzae strains, enrolling 217 publicly available genomes, as well as 88 newly sequenced H. influenzae invasive strains isolated in Portugal, spanning a 24-year period. NTHi isolates presented a core-SNP-based genetic diversity about 10-fold higher than the one observed for Hib. The analysis of key factors involved in pathogenesis, such as lipooligosaccharides, hemagglutinating pili and High Molecular Weight-adhesins, suggests that NTHi shape its virulence repertoire, either by acquisition and loss of genes or by SNP-based diversification, likely towards host immune evasion and persistence. Discreet NTHi subpopulations structures are proposed based on core-genome supported with 17 candidate genetic markers identified in the accessory genome. Additionally, this study provides two bioinformatics tools for in silico rapid identification of H. influenzae serotypes and NTHi clades previously proposed, obviating laboratory-based demanding procedures. The present study constitutes an important genomic framework that could lay way for future studies on the genetic determinants underlying invasiveness and disease and population structure of H. influenzae.
- Molecular detection of Aspergillus in respiratory samples collected from patients at higher risk of chronic pulmonary aspergillosisPublication . Oliveira, M.; Pinto, M.; Simões, H.; Gomes, J.P.; Veríssimo, C.; Sabino, R.Objective: Aspergillosis diagnosis depends on the detection of Aspergillus in biological samples ─ usually using cultural and immunoenzyme techniques ─ but their sensitivity and specificity varies. We aimed to study the prevalence of Aspergillus in patients at higher risk of chronic pulmonary aspergillosis (i.e., HIV-infected patients and individuals with active or previous tuberculosis), and to determine the potential role of molecular approaches to increase detection of Aspergillus in respiratory samples. Methods: The DNA extracted from 43 respiratory samples that had been previously analyzed by immunoenzyme and/or cultural techniques was amplified by real-time multiplex PCR, and the results of these methods were compared. We also sequenced the ITS1 region and the calmodulin gene in 10 respiratory samples to perform a pilot metagenomic study to understand the ability of this methodology to detect potential pathogenic fungi in the lung mycobiome. Results: Real-time Aspergillus PCR test exhibited a higher positivity rate than the conventional techniques used for aspergillosis diagnosis, particularly in individuals at risk for chronic pulmonary aspergillosis. The metagenomic analysis allowed for the detection of various potentially pathogenic fungi. Conclusions: Molecular techniques, including metagenomics, have great ability to detect potentially pathogenic fungi rapidly and efficiently in human biological samples.