Metal contamination in urban park soils of SA o pound Paulo

There has been little research on metal concentration levels in urban soils of SA o pound Paulo, a city with 19 million inhabitants with severe pollution problems. In the present study, the concentration of As, Ba, Cr, Cu, Pb, Sb and Zn, were determined by INAA and XRF in surface soil samples from 7 public parks located within SA o pound Paulo city. The results obtained showed that soils of SA o pound Paulo public parks present concentration levels of the studied elements higher than the reference values for soils in SA o pound Paulo State. Traffic related elements such as Cu, Pb and Zn presented high concentrations in parks located near avenues of highly dense traffic and may be associated to vehicular sources.

Occupational airborne contamination in South Brazil: 2. Oxidative stress detected in the blood of workers of incineration of hospital residues

One of the most useful methods for elimination of solid residues of health services (SRHS) is incineration. However, it also provokes the emission of several hazardous air pollutants such as heavy metals, furans and dioxins, which produce reactive oxygen species and oxidative stress. The present study, which is parallel to an accompanied paper (Avila Jr. et al., this issue), investigated several enzymatic and non-enzymatic biomarkers of oxidative stress in the blood (contents of vitamin E, lipoperoxidation = TBARS, reduced glutathione = GSH, oxidized glutathione = GSSG, and activities of glutathione S-transferase = GST, glutathione reductase = GR, glutathione peroxidase = GPx, catalase = CAT and superoxide dismutase = SOD), in three different groups (n = 20 each) exposed to airborne contamination associated with incineration of SRHS: workers directly (ca. 100 m from the incinerator) and indirectly exposed (residents living ca. 5 km the incineration site), and controls (non-exposed subjects). TBARS and GSSG levels were increased whilst GSH, TG and alpha-tocopherol contents were decreased in workers and residents compared to controls. Increased GST and CAT activities and decreased GPx activities were detected in exposed subjects compared to controls, while GR did not show any difference among the groups. In conclusion, subjects directly or indirectly exposed to SRHS are facing an oxidative insult and health risk regarding fly ashes contamination from SRHS incineration.

Antioxidant therapy attenuates oxidative stress in the blood of subjects exposed to occupational airborne contamination from coal mining extraction and incineration of hospital residues

Coal mining and incineration of solid residues of health services (SRHS) generate several contaminants that are delivered into the environment, such as heavy metals and dioxins. These xenobiotics can lead to oxidative stress overgeneration in organisms and cause different kinds of pathologies, including cancer. In the present study the concentrations of heavy metals such as lead, copper, iron, manganese and zinc in the urine, as well as several enzymatic and non-enzymatic biomarkers of oxidative stress in the blood (contents of lipoperoxidation = TBARS, protein carbonyls = PC, protein thiols = PT, alpha-tocopherol = AT, reduced glutathione = GSH, and the activities of glutathione S-transferase = GST, glutathione reductase = GR, glutathione peroxidase = GPx, catalase = CAT and superoxide dismutase = SOD), in the blood of six different groups (n = 20 each) of subjects exposed to airborne contamination related to coal mining as well as incineration of solid residues of health services (SRHS) after vitamin E (800 mg/day) and vitamin C (500 mg/day) supplementation during 6 months, which were compared to the situation before the antioxidant intervention (Avila et al., Ecotoxicology 18:1150-1157, 2009; Possamai et al., Ecotoxicology 18:1158-1164, 2009). Except for the decreased manganese contents, heavy metal concentrations were elevated in all groups exposed to both sources of airborne contamination when compared to controls. TBARS and PC concentrations, which were elevated before the antioxidant intervention decreased after the antioxidant supplementation. Similarly, the contents of PC, AT and GSH, which were decreased before the antioxidant intervention, reached values near those found in controls, GPx activity was reestablished in underground miners, and SOD, CAT and GST activities were reestablished in all groups. The results showed that the oxidative stress condition detected previously to the antioxidant supplementation in both directly and indirectly subjects exposed to the airborne contamination from coal dusts and SRHS incineration, was attenuated after the antioxidant intervention.

Occupational airborne contamination in south Brazil: 1. Oxidative stress detected in the blood of coal miners

Reactive oxygen species and nitrogen species have been implicated in the pathogenesis of coal dust-induced toxicity. The present study investigated several oxidative stress biomarkers (Contents of lipoperoxidation = TBARS, reduced = GSH, oxidized = GSSG and total glutathione = TG, alpha-tocopherol, and the activities of glutathione S-transferase = GST, glutathione reductase = GR, glutathione peroxidase = GPx, catalase = CAT and superoxide dismutase = SOD), in the blood of three different groups (n = 20 each) exposed to airborne contamination associated with coal mining activities: underground workers directly exposed, surface workers indirectly exposed, residents indirectly exposed (subjects living near the mines), and controls (non-exposed subjects). Plasma TBARS were increased and whole blood TG and GSH levels were decreased in all groups compared to controls. Plasma alpha-tocopherol contents showed approximately half the values in underground workers compared to controls. GST activity was induced in workers and also in residents at the vicinity of the mining plant, whilst CAT activity was induced only in mine workers. SOD activity was decreased in all groups examined, while GPx activity showed decreased values only in underground miners, and GR did not show any differences among the groups. The results showed that subjects directly and indirectly exposed to coal dusts face an oxidative stress condition. They also indicate that people living in the vicinity of the mine plant are in health risk regarding coal mining-related diseases.

Effects of milk supplementation with skim milk powder, whey protein concentrate and sodium caseinate on acidification kinetics, rheological properties and structure of nonfat stirred yogurt

Milk supplementation with milk proteins in four different levels was used to investigate the effect on acidification and textural properties of yogurt. Commercial skim milk powder was diluted in distilled water, and the supplements were added to give different enriched-milk bases; these were heat treated at 90 degrees C for 5 min. These mixtures were incubated with the bacterial cultures for fermentation in a water bath, at 42 degrees C, until pH 4.50 was reached. Chemical changes during fermentation were followed by measuring the pH. Protein concentration measurements, microbial counts of Lactobacillus bulgaricus and Streptococcus thermophilus, and textural properties (G`, G ``, yield stress and firmness) were determined after 24 h of storage at 4 degrees C. Yogurt made with milk supplemented with sodium caseinate resulted in significant properties changes, which were decrease in fermentation time, and increase in yield stress, storage modulus, and firmness, with increases in supplement level. Microstructure also differed from that of yogurt produced with milk supplemented with skim milk powder or sodium caseinate. (C) 2009 Elsevier Ltd. All rights reserved.

Fabrication of disposable voltammetric electronic tongues by using Prussian Blue films electrodeposited onto CD-R gold surfaces and recognition of milk adulteration

A new approach to fabricate a disposable electronic tongue is reported. The fabrication of the disposable sensor aimed the integration of all electrodes necessary for measurement in the same device. The disposable device was constructed with gold CD-R and copper sheets substrates and the sensing elements were gold, copper and a gold surface modified with a layer of Prussian Blue. The relative standard deviation for signals obtained from 20 different disposable gold and 10 different disposable copper electrodes was below 3.5%. The performance, electrode materials and the capability of the device to differentiate samples were evaluated for taste substances model, milk with different pasteurization processes (homogenized/pasteurized, ultra high temperature (UHT) pasteurized and UHT pasteurized with low fat content) and adulterated with hydrogen peroxide. In all analysed cases, a good separation between different samples was noticed in the score plots obtained from the principal component analysis (PCA). Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.

Spin contamination in XOO radicals X = F, Cl, Br, HO: How is the investigation of the HOOO radical affected

We have analysed the effect of spin contamination in the wavefunction of HOOO. At least, two solutions can be found for the HF wavefunction. One, lower in energy, presents a high spin contamination and gives qualitatively incorrect structural parameters. On the other hand, the less contaminated HF reference gives structural parameters that are in better agreement with experiment, and positive spin densities on all atoms. Some of the problems described during previous investigations of HOOO can now be traced to problems in the HF reference. For the first time we report a CCSD(T) estimation of the structure of HOOO cis employing a HF reference with small spin contamination. (C) 2008 Elsevier B.V. All rights reserved.

Effect of cold storage on culture viability and some rheological properties of fermented milk prepared with yogurt and probiotic bacteria

We examined the effect of storage time on culture viability and some rheological properties (yield stress, storage modulus, loss modulus, linear viscoelastic region, structural recuperation and firmness) of fermented milk made with Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus acidophilus (LA) and Bifidobacterium animalis ssp. lactis in coculture with Streptococcus thermophilus (ST). Acidification profiles and factors that affect viability (postfermentation acidification, acidity and dissolved oxygen) were also studied during 35 days at 4C. Fermented milk prepared with a coculture of ST and Bifidobacterium lactis gave the most constant rheological behavior and the best cell viability during cold storage; it was superior to ST plus LA for probiotic fermented milk production.

Optimization of the rheological properties of probiotic yoghurts supplemented with milk proteins

This study aimed to optimize the rheological properties of probiotic yoghurts supplemented with skimmed milk powder (SMP) whey protein concentrate (WPC) and sodium caseinate (Na-Cn) by using an experimental design type simplex-centroid for mixture modeling It Included seven batches/trials three were supplemented with each type of the dairy protein used three corresponding to the binary mixtures and one to the ternary one in order to increase protein concentration in 1 g 100 g(-1) of final product A control experiment was prepared without supplementing the milk base Processed milk bases were fermented at 42 C until pH 4 5 by using a starter culture blend that consisted of Streptococcus thermophilus Lactobacillus delbrueckii subsp bulgaricus and Bifidobacterium (Humans subsp lactis The kinetics of acidification was followed during the fermentation period as well the physico-chemical analyses enumeration of viable bacteria and theological characteristics of the yoghurts Models were adjusted to the results (kinetic responses counts of viable bacteria and theological parameters) through three regression models (linear quadratic and cubic special) applied to mixtures The results showed that the addition of milk proteins affected slightly acidification profile and counts of S thermophilus and B animal`s subsp lactis but it was significant for L delbrueckii subsp bulgaricus Partially-replacing SMP (45 g/100 g) with WPC or Na-Cn simultaneously enhanced the theological properties of probiotic yoghurts taking into account the kinetics of acidification and enumeration of viable bacteria (C) 2010 Elsevier Ltd All rights reserved

A New Indirect Electroanalytical Method to Monitor the Contamination of Natural Waters with 4-Nitrophenol Using Multiwall Carbon Nanotubes

The electrochemical detection of the hazardous pollutant 4-nitrophenol (4-NP) at low potentials, in order to avoid matrix interferences, is an important research challenge. This study describes the development, electrochemical characterization and utilization of a multiwall carbon nanotube (MWCNT) film electrode for the quantitative determination of 4-NP in natural water. Electrochemical impedence spectroscopy measurements showed that the modified surface exhibits a decrease of ca. 13 times in the charge transfer resistance when compared with a bare glassy carbon (GC) surface. Voltammetric experiments showed the possibility to oxidize a hydroxylamine layer (produced by the electrochemical reduction of 4-NP on the GC/MWNCT surface) in a potential region which is approximately 700 mV less positive than that needed to oxidize 4-NP, thus minimizing the interference of matrix components. The limit of detection for 4-NP obtained using square-wave voltammetry (0.12 mu mol L(-1)) was lower than the value advised by EPA. A natural water sample from a dam located in Sao Carlos (Brazil) was spiked with 4-NP and analyzed by the standard addition method using thee GC/MWCNT electrode, without any further purification step. the recovery procedure yielded a value of 96.5% for such sample, thus confirming the suitability of the developed method to determine 4-NP in natural water samples. The electrochemical determination was compared with that obtained by HPLC with UV-vis detection.

The role of HBF(4) in electro-catalysis: Arsenic contamination and anion adsorption

We present in this work a comprehensive investigation of the role played by dissolved tetrafluoroboric acid on the electrochemical response of a polycrystalline platinum electrode in acidic media. HBF(4) from two different suppliers was employed and characterized in terms of the amount of arsenic contamination by Inductively Coupled Plasma-Optical Emission Spectroscopy. The effect of different amounts of HBF(4) on the voltammetric profile of the Pt vertical bar HClO(4)(aq) interface was investigated by means of electrochemical quartz crystal nanobalance (EQCN). Despite the comparable cyclic voltammograms, the presence of arsenic in one of the two HBF(4) used resulted in dramatic variations in the mass change profile, which evidences the deposition/dissolution of arsenic prior to the surface oxidation. For the arsenic-free HBF(4), its effect on the mass change profile was mainly associated to anion adsorption. The impact of dissolved HBF(4) on the electro-oxidation of formic acid was rationalized in terms of two contributions: current enhancement at low potentials due to the arsenic-assisted formic acid electro-oxidation and inhibition at high potentials due to anion adsorption. (C) 2011 Elsevier B.V. All rights reserved.

On the contamination of confidence

Contaminação da confiança é um caso especial de incerteza Knightiana ou ambiguidade na qual o tomador de decisões está diante de não apenas uma única distribuição de probabilidades, mas sim de um conjunto de distribuições de probabilidades. A primeira parte desta tese tem o propósito de fornecer uma caracterização da contaminação da confiança e então apresentar um conjunto de axiomas comportamentais simples sob os quais as preferências de um tomador de decisões é representada pela utilidade esperada de Choquet com contaminação da confiança. A segunda parte desta tese apresenta duas aplicações econômicas de contaminação da confiança: a primeira delas generaliza o teorema de existência de equilíbrio de Nash de Dow e Werlang (o que permite apresentar uma solução explícita para o paradoxo segundo o qual os jogadores de um jogo do dilema dos prisioneiros com um número infinito de repetições não agem de acordo com o esperado pelo procedimento da indução retroativa) e a outra estuda o impacto da contaminação da confiança na escolha de portfolio.

Influence of a Brazilian sewage outfall on the toxicity and contamination of adjacent sediments

The submarine sewage outfall of Santos (SSOS) is situated in the Santos Bay (São Paulo, Brazil) and is potentially a significant source of contaminants to the adjacent marine ecosystem. The present study aimed to assess the influence of SSOS on the sediment toxicity and contamination at Santos Bay. At the disposal site, sediments tended to be finer, organically richer and exhibited higher levels of surfactants and metals, sometimes exceeding the Threshold Effect Level values. The SSOS influence was more evident toward the East, where the sediments exhibited higher levels of TOC, total S and metals during the summer 2000 sampling campaign. Sediment toxicity to amphipods was consistently detected in four of the five stations studied. Amphipod survival tended to correlate negatively to Hg, total N and % mud. This work provides evidence that the SSOS discharge affects the quality of sediments from Santos Bay, and that control procedures are warranted. (c) 2005 Elsevier Ltd. All rights reserved.

Chronic contamination assessment integrating biomarkers' responses in transplanted mussels-A seasonal monitoring

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Contamination of port zone sediments by metals from Large Marine Ecosystems of Brazil

Sediment contamination by metals poses risks to coastal ecosystems and is considered to be problematic to dredging operations. In Brazil, there are differences in sedimentology along the Large Marine Ecosystems in relation to the metal distributions. We aimed to assess the extent of Al, Fe, Hg, Cd, Cr, Cu, Ni, Pb and Zn contamination in sediments from port zones in northeast (Mucuripe and Pecem) and southeast (Santos) Brazil through geochemical analyses and sediment quality ratings. The metal concentrations found in these port zones were higher than those observed in the continental shelf or the background values in both regions. In the northeast, metals were associated with carbonate, while in Santos, they were associated with mud. Geochemical analyses showed enrichments in Hg, Cd, Cu, Ni and Zn, and a simple application of international sediment quality guidelines failed to predict their impacts, whereas the use of site-specific values that were derived by geochemical and ecotoxicological approaches seemed to be more appropriate in the management of the dredged sediments. (C) 2012 Elsevier Ltd. All rights reserved.