20 resultados para CONTAMINATION
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo
Resumo:
Polycyclic aromatic hydrocarbons (PAHs) and non-aromatic hydrocarbons (NAHs), including n-alkanes, isoprenoids and petroleum biomarkers (terpanes, hopanes, steranes and diasteranes), were quantified by gas chromatography with flame ionization and mass spectrometer detectors in sediment samples collected from the Sao Sebastiao Channel (SSC), Brazil, where the largest Brazilian maritime petroleum terminal is located The concentrations of total PAHs. total n-alkanes and petroleum biomarkers ranged from below the detection limits to 370 ng g(-1,) 28 mu g g(-1), 2200 ng g(-1) (dry weight), respectively. The analysis of PAN distribution suggested combustion sources of PAHs as the main input for these compounds with smaller amount from petroleum contamination The distribution of petroleum biomarkers undoubtedly demonstrated petroleum as a source of anthropogenic contamination throughout the region. The assessment of petrogenic sources of contamination in marine sediment is more challenging if only PAH analysis were carried out, which demonstrates that more stable hydrocarbons such as petroleum biomarkers are useful for investigating potential presence of petroleum (C) 2009 Elsevier Ltd. All rights reserved.
Resumo:
Biomarkers as lipid peroxidation, metallothionein and delta-aminolevulinic acid dehydratase were determined in Cathorops spixii to compare the biological responses of this fish from estuaries with distinct anthropogenic influence. Three areas were selected in two estuaries in accordance with the levels of contamination for the polluted (Santos/So Vicente) and with the hydrodynamic characteristics for the non-polluted (Canan,ia) estuary. Water characteristics and mercury levels in C. spixii confirmed a high human influence in the polluted system. In general, the biomarkers showed differences between the estuaries, suggesting disturbances in the specific cell mechanisms due to the presence of multiple xenobiotics in the contaminated system. Therefore, these biomarkers are recommended to promote more accurate information about the exposure to pollutants. Additionally, the study of the effect of the multiple xenobiotics on resident species such as the benthic fish C. spixii can favor a better assessment of the environmental quality of these systems.
Resumo:
Petroleum contamination impact on macrobenthic communities in the northeast portion of Todos os Santos Bay was assessed combining in multivariate analyses, chemical parameters such as aliphatic and polycyclic aromatic hydrocarbon indices and concentration ratios with benthic ecological parameters. Sediment samples were taken in August 2000 with a 0.05 m(2) van Veen grab at 28 sampling locations. The predominance of n-alkanes with more than 24 carbons, together with CPI values close to one, and the fact that most of the stations showed UCM/resolved aliphatic hydrocarbons ratios (UCM:R) higher than two, indicated a high degree of anthropogenic contribution, the presence of terrestrial plant detritus, petroleum products and evidence of chronic oil pollution. The indices used to determine the origin of PAH indicated the occurrence of a petrogenic contribution. A pyrolytic contribution constituted mainly by fossil fuel combustion derived PAH was also observed. The results of the stepwise multiple regression analysis performed with chemical data and benthic ecological descriptors demonstrated that not only total PAH concentrations but also specific concentration ratios or indices such as >= C24:< C24, An/178 and Fl/Fl + Py, are determining the structure of benthic communities within the study area. According to the BIO-ENV results petroleum related variables seemed to have a main influence on macrofauna community structure. The PCA ordination performed with the chemical data resulted in the formation of three groups of stations. The decrease in macrofauna density, number of species and diversity from groups III to I seemed to be related to the occurrence of high aliphatic hydrocarbon and PAH concentrations associated with fine sediments. Our results showed that macrobenthic communities in the northeast portion of Todos os Santos Bay are subjected to the impact of chronic oil pollution as was reflected by the reduction in the number of species and diversity. These results emphasise the importance to combine in multivariate approaches not only total hydrocarbon concentrations but also indices, isomer pair ratios and specific compound concentrations with biological data to improve the assessment of anthropogenic impact on marine ecosystems. (c) 2008 Elsevier Ltd. All rights reserved.
Resumo:
Chlorinated pesticides, PCBs and PBDEs were analysed in nine blubber samples of Atlantic spotted dolphins, Stenella frontalis, incidentally captured during fishing operations in southern and southeastern Brazil between 2005 and 2007. The majority of compounds analysed were detected, suggesting widespread contamination over the region. Although the samples came from a location far from main coastal industrial areas, the results revealed an influence from such sources. Therefore, levels of PCBs (774-23659 ng g(-1) lipid wt.) and PBDEs (23-1326 ng g(-1) lipid wt.) detected seem to be related to the movement of individuals throughout near-shore and offshore waters. The sample from a lactating female exhibited a lower level of contamination and a distinct pattern, indicating selective transfer favouring less lipophilic compounds.
Resumo:
This paper presents the results of electrical resistivity methods in the area delineation that was potentially contaminated by liquefaction products, which are also called putrefactive liquids in Vila Rezende municipal cemetery, Piracicaba, So Paulo, Brazil. The results indicate a depth of water table between 3.1 and 5.1 m, with two groundwater direction flows, one to the SW and another to the SE. Due to the contamination plumes, which have the same groundwater direction flow, as well the conductive anomalies observed in the geoelectric sections, the contamination suspicions in the area were confirmed. The probable plume to the SE extends beyond the limits of the cemetery. The location of the conductive anomalies and the probable contamination plumes showed that the contamination is linked with the depth of the water table and the burial time. Mapping using the geostatistical method of ordinary kriging applied to the work drew structural characteristics of the regional phenomenon and spatial behavior of the electrical resistivity data, resulting in continued surfaces. Thus, this method has proved to be an important tool for mapping contamination plumes in cemeteries.
Resumo:
Introduction: Knowing the microbiota that colonizes orthodontic appliances is important for planning strategies and implementing specific preventive measures during treatment. The purpose of this clinical trial was to evaluate in vivo the contamination of metallic orthodontic brackets with 40 DNA probes for different bacterial species by using the checkerboard DNA-DNA hybridization (CDDH) technique. Methods: Eighteen patients, 11 to 29 years of age having fixed orthodontic treatment, were enrolled in the study. Each subject had 2 new metallic brackets bonded to different premolars in a randomized manner. After 30 days, the brackets were removed and processed for analysis by CDDH. Data on bacterial contamination were analyzed descriptively and with the Kruskal-Wallis and Dunn post tests (alpha = 0.05). Forty microbial species (cariogenic microorganisms, bacteria of the purple, yellow, green, orange complexes, "red complex + Treponema socranskii," and the cluster of Actinomyces) were assessed. Results: Most bacterial species were present in all subjects, except for Streptococcus constellatus, Campylobacter rectus, Tannerella forsythia, T socranskii, and Lactobacillus acidophillus (94.4%), Propionibacterium acnes I and Eubacterium nodatum (88.9%), and Treponema denticola (77.8%). Among the cariogenic microorganisms, Streptococcus mutans and Streptococcus sobrinus were found in larger numbers than L acidophillus and Lactobacillus casei (P < 0.001). The periodontal pathogens of the orange complex were detected in larger numbers than those of the "red complex + T socranskii" (P < 0.0001). Among the bacteria not associated with specific pathologies, Veillonella parvula (purple complex) was the most frequently detected strain (P < 0.0001). The numbers of yellow and green complex bacteria and the cluster of Actinomyces were similar (P > 0.05). Conclusions: Metallic brackets in use for 1 month were multi-colonized by several bacterial species, including cariogenic microorganisms and periodontal pathogens, reinforcing the need for meticulous oral hygiene and additional preventive measures to maintain oral health in orthodontic patients. (Am J Orthod Dentofacial Orthop 2012;141:24-9)
Resumo:
Analyses of living foraminiferal and environmental parameters near an outfall at Mar Grosso Beach (Laguna, SC, Brazil) demonstrate its usefulness as indicators of domestic sewage pollution. The low species diversity may be due to sand accumulation in the central part. Higher diversity was noted closer to the mouth of Laguna estuarine system where reduced salinity and higher temperatures indicate freshwater influence, suggesting a relationship between increased diversity and greater availability of terrestrial food. On the basis of foraminiferal diversity and average coliform count the higher values are closer to the mouth of the estuarine system and under the influence of the outfall. Due to the effect of local hydrodynamics, the particulate organic waste derived from the outfall does not settle down locally, and thus, do not accumulate nearby. Our hypothesis is that the fine material derived from the outfall is accumulating on the southwestern and northwestern parts of the beach.
Resumo:
Objective: The presence and survival of microorganisms on toothbrush bristles might play a role on the etiology of oral infections. The aim of this in vitro study was to evaluate the presence of bacterial contamination on new toothbrushes before oral contact. Materials and methods: Forty toothbrushes from five different manufacturers were used in this experimental study. Each manufacturer was divided according to conventional local of obtaining: industry, drugstore, market, and perfumery. The toothbrush heads were completely immersed into tubes containing 5.0 mL of sterile peptonated water (dilution 1:10). A group of eight tubes containing the sterile solution was used as control. After 21 days of anaerobic incubation, occurrence of contamination was visually evaluated and confirmed by light microscopy. Results: Bacterial growth in the medium, indicative of bristles contamination, was found in a total of 19 out of 40 samples (47.5%) evaluated: 6 out of 14 samples (42.85%) from industry group, 4 out of 8 samples (50.0%) from drugstore, 5 out of 10 samples (50.0%) from market, and 4 out of 8 samples (50.0%) from perfumery. Only the toothbrushes with bristles coated with chlorhexidine did not show contamination. The Gram-negative sporulating bacilli were the most prevalent form recovered. Conclusions: Except for chlorhexidine group, bacterial growth was observed in all groups evaluated irrespective local of obtaining. Microsc. Res. Tech., 2012. (c) 2011 Wiley Periodicals, Inc.
Resumo:
This study aimed to provide the first biomonitoring integrating biomarkers and bioaccumulation data in Sao Paulo coast, Brazil and, for this purpose, a battery of biomarkers of defense mechanisms was analyzed and linked to contaminants' body burden in a weigh-of-evidence approach. The brown mussel Perna perna was selected to be transplanted from a farming area (Caraguatatuba) to four possibly polluted sites: Engenho D'Agua, DTCS (Dutos e Terminais do Centro-Oeste de Sao Paulo) oil terminal (Sao Sebastiao zone), Palmas Island, and Itaipu (It; Santos Bay zone). After 3 months of exposure in each season, mussels were recollected and the cytochrome P4501A (CYP1A)- and CYP3A-like activities, glutathione-S-transferase and antioxidants enzymes (catalase, glutathione peroxidase, and glutathione reductase) were analyzed in gills. The concentrations of polycyclic aromatic hydrocarbons, linear alkylbenzenes, and nonessential metals (Cr, Cd, Pb, and Hg) in whole tissue were also analyzed and data were linked to biomarkers' responses by multivariate analysis (principal component analysisfactor analysis). A representation of estimated factor scores was performed to confirm the factor descriptions and to characterize the studied stations. Biomarkers exhibited most significant alterations all year long in mussels transplanted to It, located at Santos Bay zone, where bioaccumulation of organic and inorganic compounds was detected. This integrated approach using transplanted mussels showed satisfactory results, pointing out differences between sites, seasons, and critical areas, which could be related to land-based contaminants' sources. The influence of natural factors and other contaminants (e.g., pharmaceuticals) on biomarkers' responses are also discussed.
Resumo:
Different components of the mixed function oxidase (MFO) system and the levels of fluorescent aromatic compounds in bile (FACs) were measured in Cathorops spixii in order to assess the impact of polycyclic aromatic hydrocarbons (PAHs). Fish were sampled in an estuary (Santos/Sao Vicente) with a history of contamination by PAHs, mainly due to the presence of the industrial complex of Cubatao city and of another of low anthropogenic influence (Cananeia) on the Brazilian coast. FACs were higher in fish from the polluted site, and the PAH 5 and 6-ring metabolites were the most frequent - with 14% and 15%, respectively. Levels of the different components of the MFO system showed the same variation profile as the FACs for both estuaries. Therefore, the values found for somatic indexes and biomarkers with data of bile PAH metabolites indicate the presence of organic contaminants, especially in the area subject to the influence of the industrial complex on the Santos/Sao Vicente estuary.
Resumo:
Soil microcosms contaminated with crude oil with or without chromium and copper were monitored over a period of 90 days for microbial respiration, biomass, and for dehydrogenase, lipase, acid phosphatase, and arylsulfatase activities. In addition, the community structure was followed by enumerating the total heterotrophic and oil-degrading viable bacteria and by performing a denaturing gradient gel electrophoresis (DGGE) of the PCR amplified 16S rDNA. A significant difference was observed for biochemical activities and microbial community structures between the microcosms comprised of uncontaminated soil, soil contaminated with crude oil and soil contaminated with crude oil and heavy metals. The easily measured soil enzyme activities correlated well with microbial population levels, community structures and rates of respiration (CO2 production). The estimation of microbial responses to soil contamination provides a more thorough understanding of the microbial community function in contaminated soil, in situations where technical and financial resources are limited and may be useful in addressing bioremediation treatability and effectiveness. (C) 2012 Published by Elsevier Ltd.
Resumo:
Purpose: To determine the incidence of Piry virus contamination among surgical instruments used with disposable accessories for phacoemulsification during sequential surgeries. Methods: An experimental model was created with 4 pigs' eyes that were contaminated with Piry virus and 4 pigs' eyes that were not contaminated. Phacoemulsification was performed on the eyes, alternating between the contaminated and non-contaminated eyes. From one surgery to another, the operating fields, gloves, scalpel, tweezers, needles, syringes, tips and bag collector from the phacoemulsification machine were exchanged; only the hand piece and the irrigation and aspiration systems were maintained. Results: In the collector bag, three samples from the contaminated eyes (3/4) were positive, and two samples from the non-contaminated (2/4) eyes were also positive; at the tip, one sample from the contaminated eyes (1/4) and two samples of the noncontaminated eyes (2/4) yielded positive results. In the irrigation system, one sample from a non-contaminated eye (1/4) was positive, and in the aspiration system, two samples from contaminated eyes (2/4) and two samples from non-contaminated eyes (2/4) were positive. In the gloves, the samples were positive in two samples from the non-contaminated eyes (2/4) and in two samples from the contaminated eyes (2/4). In the scalpel samples, three contaminated eyes (3/4) and none of the non-contaminated eyes (0/4) were positive; finally, two samples from the anterior chambers of the non-contaminated eyes gathered after surgery were positive. Conclusions: In two non-contaminated eyes, the presence of genetic material was detected after phacoemulsification surgery, demonstrating that the transmission of the genetic material of the Piry virus occurred at some point during the surgery on these non-contaminated eyes when the hand piece and irrigation and aspiration systems were reused between surgeries.
Resumo:
An investigation was conducted to test the hypothesis that the storage time of packaging sterility has no effect on contamination susceptibility even under deliberate bacterial exposure (Serratia marcescens). No growth of the test microorganisms was identified in the experimental group in any of the storage intervals (7, 14, 28, 90, and 180 days). Current recommendations/guidelines suggest that contamination of packaging occurs only because of events. This study, done in vitro, supports these recommendations. Copyright (c) 2012 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.
Resumo:
Increased agricultural activity in watershed areas has been causing concern over contamination by herbicides in agricultural areas. The problem becomes more important when contamination can affect water for human consumption, as happens with water from the Poxim river, which supplies the city of Aracaju, capital of the State of Sergipe. The aim of this study was to evaluate the risk of contamination by herbicides to both surface and groundwater in the upper sub-basin of the Poxim River, and to detect the presence of the active ingredients Diuron and Ametrine up-river from the sugar-cane plantations. Risk analysis was carried out using criteria from the Environmental Protection Agency (EPA), the GUS index, and the GOSS method. It was observed that several active ingredients are at risk of leaching, demonstrating the importance of monitoring the river to control both the quality of water and the frequency and volume of herbicides used in the region. Based on the results, monitoring was carried out bi-monthly from July 2009 to July 2010 at two sampling points. Water samples were analyzed in the laboratory, where the presence of Diuron and Ametrine was noted. Water quality in the Sub-basin of the Rio Poxim is being influenced by the use of herbicides in the region. There was an increase in herbicide concentration in the surface water during the rainy season, possibly caused by soil runoff.