Malignant mammary tumor in female dogs: environmental contaminants

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

New materials based on modified synthetic Nb2O5 as photocatalyst for oxidation of organic contaminants

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Electrochemical Determination of Inorganic Contaminants in Automotive Fuels

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of Ionic Liquid on the Determination of Aromatic Amines as Contaminants in Hair Dyes by Liquid Chromatography Coupled to Electrochemical Detection

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cathodic stripping voltammetric detection and determination at a hanging mercury-drop electrode of dye contaminants in purified biomaterials: study of the human serum albumin and reactive dye 120 system

Procion red HE-3B (RR120) is an example of dye currently used in affinity purification. A method is described for determining trace amounts of RR120 dye contaminant in human serum albumin by cathodic stripping voltammetry. The method is based on a measure of a well-defined peak at -0.58 V, obtained when samples of HSA protein (0.01-2% w/v) containing dye concentrations are submitted to a heating time of 330 min at 80degreesC in NaOH, pH 12.0 and the samples are removed to a solution containing Britton-Robinson buffer, pH 4.0. Using an optimum accumulation potential and tune of 0 V and 240 s, respectively, linear calibration curves were obtained from 1.0 X 10(-9) to 1.0 X 10(-8) mol 1(-1) for RR120 dye. Leakage/hydrolysis of reactive red 120 from an agarose support (e.g. at pH 2 or 12) can also be conveniently determined at very low levels (sub-mug ml(-1)) by means of cathodic stripping voltammetry, which involves adsorptive accumulation of the dye onto the hanging mercury-drop electrode. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Effect of 3,4,4 '-trichlorocarbanilide on growth of lactic acid bacteria contaminants in alcoholic fermentation

3,4,4'-trichlorocarbanilide (TCC) was rested as a new method of bacterial growth control for S. cerevisiae alcoholic fermentations of diluted high test molasses (HTM). Minimal inhibitory concentration (MIC) was tested to determine the necessary concentration of TCC to control bacterial growth. The fed-batch alcoholic fermentation process was used with cell recycle similar to industrial conditions and Lactobacillus fermentum CCT 1407 was mixed in the first inoculum to grow with the yeast. Yeast extract was added into the must to stimulate bacterial growth. The best results of TCC's MIC to bacterial growth of Lactobacillus fermentum and Leuconostoc mesenteroides (< 0.125-1.0 mu g/ml) and Saccharomyces cerevisiae (16 mu g/ml) occurred when it was combined with sodium dodecylsulphate (SDS) in a 1: 4 TCC/SDS ratio (wt/wt) in distilled water solution. 1.8 g/l TCC entrapped in calcium alginate added to the must with yeast extract inhibited the growth of Lactobacillus fermentum CCT 1407 maintaining a controlled acidity, higher yeast viability and up to 20.8% of improvement in the average of alcoholic efficiency. Addition of 0.075 g/l TCC entrapped in calcium alginate and 1.67 mg/l SDS in the wort with yeast extract (0-5.0 g/l), inhibited and controlled the extensive bacterial contamination for 19 cycles of fermentation. (C) 1998 Published by Elsevier B.V. Ltd.

Impact of an environmentally realistic intake of water contaminants and superoxide formation on tissues of rats

Water contaminants have a high potential risk for the health of populations and for this reason their toxic effects urgently should be established. The present study was carried out to determine whether an environmentally realistic intake of water contaminants can induce tissue lesions, and to clarify the contribution of superoxide radical (O-2(.-)) formation to this effect. Male Wistar rats were given drinking water from the Tiett River (group A) and from the Capivara River (group B). The increased creatinine, glucose, alanine transaminase and amylase levels in serum reflected the toxic effects of river-water contaminants to renal, pancreatic and hepatic tissues of rats. As changes in lipoperoxide were observed in rats after river-water intake while superoxide dismutase activities decreased in these animals, it is assumed that the superoxide anion elicits lipoperoxide formation and induces tissue damage. There is evidence that oxygen tension reflects water pollution, since river-water with a-low oxygen tension induced more elevated toxicity in rat tissues. (C) 1999 Elsevier B.V. Ltd. All rights reserved.

PATHOGENIC OR POTENTIALLY PATHOGENIC BACTERIA AS CONTAMINANTS OF FRESH-WATER FROM DIFFERENT SOURCES IN ARARAQUARA, BRAZIL

The microbiological quality of various fresh waters in the Araraquara region, state of São Paulo, Brazil was investigated. Ninety-nine water samples were taken from rivers, reservoirs, artesian and non-artesian wells, springs and tap waters, and these waters were analysed using: plate counts of heterotrophic microorganisms (per 1 ml); Most Probable Number (MPN) of fecal coliforms and E. coli (per 100 ml); tests for presence of Salmonella, Shigella, Yersinia, the E. coli pathogens of classes EPEC, ETEC and EIEC and Mycobacterium, Shigella, Yersinia and enteroinvasive E. coli (EIEC) were not isolated. The other types of microorganisms were isolated in varying proportions. We conclude that the waters investigated represent a potential microbiological health risk.

Toxicogenetic monitoring in urban cities exposed to different airborne contaminants

Microparticles found in the air may be associated with organic matter that contains several compounds, such as Polycyclic Aromatic Hydrocarbons (PAHs) and nitro-PAHs, and may pose a significant risk to human health, possibly leading to DNA mutations and cancers. This study associated genotoxicity assays for evaluating human exposure with the atmospheric air of two urban areas in southern Brazil, that received different atmospheric contributions. Site 1 was under urban-industrial influence and the other was a non-industrial reference, Site 2. Organic extracts from the airborne particulate matter were tested for mutagenicity via the Salmonella/microsome assay and analyzed for PAH composition. Cells samples of people residing in these two cities were evaluated using the comet and micronucleus assay (MN).Concentrations of the individual PAHs ranged from 0.01ng/m3 (benzo[a]anthracene) to 5.08ng/m3 (benzo[ghi]perylene). As to mutagenicity analysis of airborne, Site 1 presented all the mutagenic responses, which varied from 3.2±1.22rev/m3 (TA98 no S9) to 32.6±2.05rev/m3 (TA98, S9), while Site 2 ranged from negative to minimal responses. Site 1 presented a high quantity of nitro and amino derivatives of PAHs, and peaked at 56.0±3.68rev/μg (YG1024 strain). The two groups presented very low DNA damage levels without intergroup difference. Although Site 1 presented high mutagenic responses in the air samples, high PAH levels, healthy people exposed to this environment did not show significative damage in their genetic material. However, the evaluation of different environmental and genetic damage in such population is necessary to monitor possible damages. © 2013 Elsevier Inc.

Chemical contaminants in juvenile gray whales (Eschrichtius robustus) from a subsistence harvest in Arctic feeding grounds

Gray whales are coastal migratory baleen whales that are benthic feeders. Most of their feeding takes place in the northern Pacific Ocean with opportunistic feeding taking place during their migrations and residence on the breeding grounds. The concentrations of organochlorines and trace elements were determined in tissues and stomach contents of juvenile gray whales that were taken on their Arctic feeding grounds in the western Bering Sea during a Russian subsistence harvest. These concentrations were compared to previously published data for contaminants in gray whales that stranded along the west coast of the US during their northbound migration. Feeding in coastal waters during their migrations may present a risk of exposure to toxic chemicals in some regions. The mean concentration (standard error of the mean, SEM) of Σ PCBs [1400 (130) ng/g, lipid weight] in the blubber of juvenile subsistence whales was significantly lower than the mean level [27 000 (11 000) ng/g, lipid weight] reported previously in juvenile gray whales that stranded in waters off the west coast of the US. Aluminum in stomach contents of the subsistence whales was high compared to other marine mammal species, which is consistent with the ingestion of sediment during feeding. Furthermore, the concentrations of potentially toxic chemicals in tissues were relatively low when compared to the concentrations in tissues of other marine mammals feeding at higher trophic levels. These chemical contaminant data for the subsistence gray whales substantially increase the information available for presumably healthy animals.

Simulations of Ground-Water Flow, Transport, Age, and Particle Tracking near York, Nebraska, for a Study of Transport of Anthropogenic and Natural Contaminants (TANC) to Public-Supply Wells

The U.S. Geological Survey (USGS) is committed to providing the Nation with credible scientific information that helps to enhance and protect the overall quality of life and that facilitates effective management of water, biological, energy, and mineral resources (http://www.usgs.gov/). Information on the Nation’s water resources is critical to ensuring long-term availability of water that is safe for drinking and recreation and is suitable for industry, irrigation, and fish and wildlife. Population growth and increasing demands for water make the availability of that water, now measured in terms of quantity and quality, even more essential to the long-term sustainability of our communities and ecosystems. The USGS implemented the National Water-Quality Assessment (NAWQA) Program in 1991 to support national, regional, State, and local information needs and decisions related to water-quality management and policy (http://water.usgs.gov/nawqa). The NAWQA Program is designed to answer: What is the condition of our Nation’s streams and ground water? How are conditions changing over time? How do natural features and human activities affect the quality of streams and ground water, and where are those effects most pronounced? By combining information on water chemistry, physical characteristics, stream habitat, and aquatic life, the NAWQA Program aims to provide science-based insights for current and emerging water issues and priorities. From 1991-2001, the NAWQA Program completed interdisciplinary assessments and established a baseline understanding of water-quality conditions in 51 of the Nation’s river basins and aquifers, referred to as Study Units (http://water.usgs.gov/nawqa/studyu.html).

Temporal and Spatial Variations of Ions, Isotopes and Agricultural Contaminants in Surface Waters and Groundwater of Nebraska's Rainwater Basin Wetland Region

The wetlands of south-central Nebraska’s Rainwater Basin region are considered of international importance as a habitat for millions of migratory birds, but are being endangered by agricultural practices. The Rainwater Basin extends across 17 counties and covers 4,000 square miles. The purpose of this study was to assemble baseline chemical data for several representative wetlands across the Rainwater Basin region, and determine the use of these chemical data for investigating groundwater recharge. Eight representative wetlands were chosen across the Rainwater Basin to monitor surface and groundwater chemistry. At each site, a shallow well and deep well were installed and sampled once in the summer of 2009 and again in the spring of 2010. Wetland surface water was sampled monthly from April, 2009 to May, 2010. Waters were analyzed for major ions, nutrients, pesticides and oxygen-18 and deuterium isotopes at the University of Nebraska Water Sciences Laboratory. Geochemical analysis of surface waters presents a range of temporal and spatial variations. Wetlands had variable water volumes, isotopic compositions, ion chemistries and agricultural contaminant levels throughout the year and, except for a few trends, theses variations cannot be predicted with certainty year-to-year or wetland-to-wetland. Isotopic compositions showed evaporation was a contributor to water loss, and thus, did impact water chemistry. Surface water nitrate concentrations ranged from <0.10 to 4.04 mg/L. The nitrate levels are much higher in the groundwater, ranging from <0.10 to 18.4 mg/L, and are of concern because they are found above the maximum contaminant level (MCL) of 10 mg/L. Atrazine concentrations in surface waters ranged from <0.05 to 10.3 ppb. Groundwater atrazine concentrations ranged from <0.05 to 0.28 ppb. The high atrazine concentrations in surface waters are of concern as they are above the MCL of 3 ppb, and the highest levels occur during the spring bird migration. Most sampled groundwaters had detectable tritium indicating a mix of modern (<5 to 10 years old) and submodern (older than 1950s) recharge. The groundwater also had differences in chemical and isotope composition, and in some cases, increased nitrate concentrations, between the two sampling periods. Modern groundwater tritium ages and changes in groundwater chemical and isotopic compositions may indicate connections with surface waters in the Rainwater Basin.

Organochlorine contaminants in albatrosses and petrels during migration in South Atlantic Ocean

Albatrosses and petrels (Procellariiformes) are migratory oceanic birds of considerable conservational interest. Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were assessed in the subcutaneous fat, liver and muscle of 100 birds belonging to eight species of Procellariiformes collected during their migration period in southern Brazil, one of the most important feeding areas for these species. Although the profiles of PCBs and OCPs were similar among the individuals, with predominance of penta, hexa and heptachlorobiphenyls and p'p-DDE, organochlorine concentrations exhibited a high degree of intra-species variability. The influence of body condition during the migration period in the distribution of organochlorine contaminants was also evaluated, showing that it is a significant factor in the variation and redistribution of these compounds in the tissues of these birds. The intense use of lipid reserves associated to the contamination from organochlorine compounds could be a troubling factor for seabirds with extended breeding periods and that spend most of their lives at sea migrating long distances, such as most of Procellariiformes. Studies on contamination are necessary to improve the knowledge of the threats to these birds and their populations as well as to contribute with information about persistent organic pollutants in the South Atlantic marine environment.

An integrated approach to evaluate emerging contaminants in drinking water

The chemical stock of emerging contaminants in Brazilian drinking water is of great interest due to the poor water quality at surface water intakes. In addition, little is known about the effect of some contaminants, such as endocrine disrupting chemicals (EDCs), which may be present in both raw and treated water. The aim of this work was to evaluate selected emerging contaminants in Brazilian waters using both chemical and biological analyses. Sampling sites were established in different municipalities based upon raw water quality data. Estrone, 17 beta-estradiol, estriol, 17 alpha-ethinylestradiol, bisphenol A, 4-n-octylphenol and 4-n-nonylphenol were determined in the samples by liquid chromatography-tandem mass spectrometry. A yeast assay using a Saccharomyces cerevisiae bioluminescent bioreporter was used to evaluate the estrogenic activity of the water samples. The first integrated results revealed similarities between the two individual approaches, since higher values for the bioassay were accompanied by significant concentrations of some selected compounds in surface water samples. No estrogenicity was observed for drinking water samples. Our results also indicate that the usual paradigm of evaluating water quality by measuring selected EDCs in a given water sample via chemical analysis, needs to be reviewed since the observed estrogenicity of a water sample is now a better guiding parameter to the selection of samples and substances to be chemically investigated in further analysis. So far, the data bank produced in this work, i.e., the comparison between chemical burden and observed estrogenicity, is not yet sufficiently robust to fully guide this decision. (C) 2011 Elsevier B.V. All rights reserved.