Browsing by Author "Mansilha, C."
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- Application of chemometric methods to assess the impact of intensive horticulture practices on groundwater content of nitrates, sodium, potassium and pesticidesPublication . Pinto, E.; Melo, A.; Aguiar, A.; Mansilha, C.; Pinho, O.; Ferreira, I.
- Bisphenol a releasing by plastic container with gas chromatography tandem mass spectometryPublication . Rocha, S.; Domingues, V.F.; Mansilha, C.; Pinho, C.; Gameiro, P.; Delerue-Matos, C.
- Contaminação de água subterrânea por substâncias de limpeza da neve em estradas: o caso do sector de Nave de Santo António – Covão do Curral (Serra da Estrela, Centro de Portugal)Publication . Carvalho, A.; Espinha Marques, J.; Marques, J.M.; Carreira, P.M.; Moura, R.; Guerner Dias, A.; Chaminé, H.I.; Rocha, F.; Saraiva, R.; Tavares, M.; Mansilha, C.Num momento em que a gestão sustentável dos recursos hídricos se assume como uma das maiores preocupações à escala mundial, as regiões de montanha têm vindo a ser reconhecidas como Reservatórios de Água (PROGRAMA UNESCO IHP-VI). O facto de muitas destas áreas se localizarem a altitudes elevadas e serem recortadas por rodovias obriga a frequentes operações de limpeza de neve, especialmente no inverno. A aplicação de substâncias químicas como cloreto de sódio e cloreto de cálcio na promoção da fusão do gelo e na limpeza da neve das estradas constitui um problema ambiental de elevado interesse científico, social e económico. Devido às suas características geológicas, geomorfológicas e climáticas, a Serra da Estrela é considerada estratégica para a gestão da água em Portugal. No presente trabalho apresentam-se alguns resultados hidrogeoquímicos que indicam que a utilização dos referidos sais na limpeza do gelo e da neve das rodovias contribui para a contaminação dos recursos hídricos.
- Determination of endocrine disruptor pesticides in river waters by SPME-GC-MSPublication . Vera, José L.; Delerue-Matos, C.; Domingues, V.F.; Fernandes, Virgínia; Mansilha, C.; Laurens, Jans
- Emerging water contaminantsPublication . Mansilha, C.; Melo, A.; Ferreira, I.; Domingues, V.; Pinho, C.; Rocha, S.; Gameiro, P.
- Evaluation of the actual standard procedures for analysis of total extractable hydrocarbons in environmental water matricesPublication . Pinho, C.; Mansilha, C.; Gameiro, P.Hundreds of different hydrocarbon compounds derived from agricultural, industrial and domestic practices are released daily into aquatic systems with adverse effects in the desirable potable characteristics, in aquatic fauna and flora, and on tourism, recreation and aesthetics of the impacted areas. Total petroleum hydrocarbon concentration data cannot be used to quantitatively estimate human health risk, but can be used as an important tool for three purposes: verifying if there is a problem, assessing the severity of the contamination and following the progress of a remediation effort. The objective of this work was the optimization of the experimental conditions for the determination of total hydrocarbons in water by liquid–liquid extraction coupled to infrared spectrophotometry, with the goal of improving the qualitative information provided by the spectra. The method was validated with satisfactory detection and quantification limits and demonstrated acceptable levels of precision, accuracy and analyte recoveries. Solid phase extraction and microwave assisted extraction procedures were tested and compared to the liquid extraction. Additionally, a spectra library was prepared with different natural and synthetic oils. The developed method was applied to the analysis of Portuguese inland and coastal bathing waters and wastewaters and their compliance with national and European legislation was assessed.
- Groundwater from infiltration galleries used for small public water supply systems: contamination with pesticides and endocrine disruptorsPublication . Mansilha, C.; Melo, A.; Ferreira, I.; Pinho, O.; Domingues, V.; Pinho, C.; Gameiro, P.Infiltration galleries are among the oldest known means used for small public water fountains. Owing to its ancestral origin they are usually associated with high quality water. Thirty-one compounds, including pesticides and estrogens from different chemical families, were analysed in waters from infiltration galleries collected in Alto Douro Demarcated Wine region (North of Portugal). A total of twelve compounds were detected in the water samples. Nine of these compounds are described as presenting evidence or potential evidence of interfering with the hormone system of humans and wildlife. Although concentrations of the target analytes were relatively low, many of them below their limit of quantification, four compounds were above quantification limit and two of them even above the legal limit of 0.1 μg/L: dimethoate (30.38 ng/L), folpet (64.35 ng/L), terbuthylazine-desethyl (22.28 to 292.36 ng/L) and terbuthylazine (22.49 to 369.33 ng/L).
- Impact of intensive horticulture practices on groundwater content of nitrates, sodium, potassium, and pesticidesPublication . Melo, A.; Pinto, E.; Aguiar, A.; Mansilha, C.; Pinho, O.; Ferreira, I.A monitoring program of nitrate, nitrite, potassium, sodium, and pesticides was carried out in water samples from an intensive horticulture area in a vulnerable zone from north of Portugal. Eight collecting points were selected and water-analyzed in five sampling campaigns, during 1 year. Chemometric techniques, such as cluster analysis, principal component analysis (PCA), and discriminant analysis, were used in order to understand the impact of intensive horticulture practices on dug and drilled wells groundwater and to study variations in the hydrochemistry of groundwater. PCA performed on pesticide data matrix yielded seven significant PCs explaining 77.67% of the data variance. Although PCA rendered considerable data reduction, it could not clearly group and distinguish the sample types. However, a visible differentiation between the water samples was obtained. Cluster and discriminant analysis grouped the eight collecting points into three clusters of similar characteristics pertaining to water contamination, indicating that it is necessary to improve the use of water, fertilizers, and pesticides. Inorganic fertilizers such as potassium nitrate were suspected to be the most important factors for nitrate contamination since highly significant Pearson correlation (r = 0.691, P < 0.01) was obtained between groundwater nitrate and potassium contents. Water from dug wells is especially prone to contamination from the grower and their closer neighbor's practices. Water from drilled wells is also contaminated from distant practices.
- In vitro bioacessibility and transport across Caco-2 monolayers of haloacetic acids in drinking waterPublication . Melo, A.; Faria, M.A.; Pinto, E.; Mansilha, C.; Ferreira, I.M.P.L.V.O.Water disinfection plays a crucial role in water safety but it is also a matter of concern as the use of disinfectants promotes the formation of disinfection by-products (DBPs). Haloacetic acids (HAAs) are one of the major classes of DBPs since they are frequently found in treated water, are ubiquitous, pervasive and have high water solubility, so a great concern emerged about their formation, occurrence and toxicity. Exposure to HAAs is influenced by consumption patterns and diet of individuals thus their bioavailability is an important parameter to the overall toxicity. In the current study the bioacessibility of the most representative HAAs (chloroacetic acid - MCAA, bromoacetic acid - MBAA, dichloroacetic acid - DCAA, dibromoacetic acid - DBAA, and trichloroacetic acid - TCAA) after simulated in vitro digestion (SIVD) in tap water and transport across Caco-2 monolayers was evaluated. Compounds were monitored in 8 points throughout the digestion phases by an optimized LC-MS/MS methodology. MCAA and MBAA were not bioaccessible after SIVD whereas DCAA, DBAA and TCAA are highly bioaccessible (85 ± 4%, 97 ± 4% and 106 ± 7% respectively). Concerning transport assays, DCAA and DBAA were highly permeable throughout the Caco-2 monolayer (apparent permeability and calculated fraction absorbed of 13.62 × 10(-6) cm/s and 90% for DCAA; and 8.82 × 10(-6) cm/s and 84% for DBAA), whereas TCAA showed no relevant permeability. The present results may contribute to efficient risk analysis studies concerning HAAs oral exposure from tap water taking into account the different biological behaviour of these chemically similar substances.
- Multi-residue analysis of 39 pesticides in surface waters of Ria de AveiroPublication . Vera, J.L.; Almeida, A.; Costa, J.M.; Domingues, V.F.; Delerue-Matos, C.; Mansilha, C.A multi-residue gas chromatography-mass spectrometry method was developed in order to evaluate the presence of 39 pesticides of different chemical families (organophosphorus, triazines, imidazole, organochlorine), as well as some of their transformation products, in surface water samples from Ria de Aveiro. Ria de Aveiro is an estuarine coastal lagoon, located in the northern west region of Portugal, which receives inputs from agriculture, urban and industrial activities. The analytical method was developed and validated according international guidelines and showed good linearity, with correlation coefficients higher than 0.9949 for all compounds, adequate precision and accuracy, and high sensitivity. Pesticides were chosen from the priority pollutants list of the Directive 2008/105/EC of the European Parliament and of the Council (on environmental quality standards in the field of water policy), or were selected due their common use in agricultural practices. Some of these 39 pesticides are, or are suspected to be, endocrine disruptor compounds (EDCs), being capable of altering the endocrine system of wildlife and humans, causing form malfunction and ultimately health problems. Even those pesticides which are not EDCs, are known to be awfully toxic and have a recognised impact in human health. The aquatic environment is particularly susceptible to pollution due to intentional and accidental release of chemicals to water [3]. Pesticide contamination of surface water is a national issue as it is often used as drinking water. This concern is especially important in rural agricultural areas where population uses small private water supplies, regularly without any laboratory surveillance. The study was performed in seven sampling points and the results showed a considerable concern pesticide contamination of all samples.