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321.
This work presents a liquid disposal monitoring originated from uranium enrichment process at Aramar Experimental Center from 1990 to 1998. Assessment of uranium, fluorides, ammoniacal nitrogen, chemical oxygen demand, and pH measurements were made in water samples and compared with results achieved in other countries, as North America and India. The liquid disposal evaluation, generated by uranium enrichment process, showed low levels, considering most parameters established by Federal and State Legislation, aiming environmental pollution control. However, uranium levels were above the limits established by Conselho Nacional do Meio Ambiente, Environment Protection Agency and mainly by the World Health Organization.  相似文献   
322.
The particulate emissions from biomass burning are a growing concern due to the recent evidence of their ubiquitous and important contribution to the ambient aerosol load. A possible strategy to apportion the biomass burning share of particulate matter is the use of organic molecular tracers. Anhydrosugars (levoglucosan, mannosan and galactosan), together with two organic acids (dehydroabietic and pimaric acids), were previously reported as organic markers for particulate wood burning emissions. These five compounds were studied in four European cities (Helsinki, Copenhagen, Birmingham and Oporto), at both a Roadside and an Urban Background station, during a summer and a winter campaign in the fine (PM(2.5)) and the coarse (PM(10-2.5)) size-fractions of the ambient aerosol. Levoglucosan concentrations were highest in the city of Oporto. In winter, levoglucosan was more present in the fine fraction but in summer, concentrations were similar in both size fractions. Levoglucosan concentrations in the fine size fraction were higher in winter, but no seasonal differences were observed for the coarse size fraction. The lack of difference between the Roadside and Urban Background levoglucosan concentrations points towards a regional nature of this type of pollution. Wood burning was estimated to contribute to about 3.1% of the winter PM(10) mass in Oporto, and to 3.7% in Copenhagen. Mannosan followed the trends exhibited by levoglucosan. The ratio between the levoglucosan and mannosan concentrations allowed determination of a preference for softwood over hardwood in all four cities. Galactosan, pimaric acid and dehydroabietic acid were found to be minor compounds.  相似文献   
323.
The search for reliable biomarkers of human exposure to benzene and its derivatives is still subject of research. Many of the proposed biomarkers have limitations ranging from the low sensitivity to the wide variability of results. Thus, the aim of our study was to assess the frequencies of chromosomal abnormalities (CA) and sister chromatid exchanges (SCE) in workers of gas stations, with (cases, n?=?19) and without (local controls, n?=?6) risk of exposure to benzene and its derivatives, comparing them with the results from the general population (external controls, n?=?38). The blood dosages of benzene, toluene, and xylenes were measured in all participants. Blood solvent levels were compared with the findings obtained in cytogenetic evaluation and a research protocol which included data of the workplace, lifestyle, and health of the individuals. We did not detect the presence of benzene and its derivatives and did not find chromosomal damage that may be associated with the gas station activity in cases. Moreover, although we found an association of increased SCE and the working time in the local controls, the values found for SCE are within normal limits. Thus, our evaluation of SCE and CA reflected the levels of benzene and its derivatives observed in the blood. We believe, therefore, that SCE and CA may actually constitute possible tests for the evaluation of these exposures. However, we believe that further studies, including individuals at risk, are important to confirm this assertion.  相似文献   
324.
The Poxim River is one of Sergipe State’s major waterways. It supplies water to the State capital, Aracaju, but is threatened by urban and agricultural developments that compromise both the quantity and the quality of the water. This has direct impacts on the daily lives of the region’s population. In this work, a multivariate analytical approach was used to investigate the physical and chemical characteristics of the water in the river basin. Four sampling campaigns were undertaken, in November 2005, and in February, May, and September 2006, at 15 sites distributed along the Poxim. The parameters analyzed were conductivity, turbidity, color, total dissolved solids, dissolved oxygen, alkalinity, hardness, chlorophyll-a, and nutrients (total phosphorus, dissolved orthophosphate, nitrite, nitrate, ammoniacal nitrogen, and total nitrogen). Dissolved oxygen contents were very low in the Poxim-Açu River (1.0–2.8), the Poxim River (1.6–4.6), and the estuarine region (1.7–5.1), due to the dumping of wastes and discharges of domestic and industrial effluents containing organic matter into fluvial and estuarine regions of the Poxim. Factor analysis identified five components that were indicative of the quality of the water, and that explained 81.73 % of the total variance.  相似文献   
325.
Biological monitoring through animals exposed to pollutants using biomarkers provides a promising tool for the identification of pollutants that may cause damage to human health and/or to sustainability of ecosystems. The effects of pollutants in fish tissues are important tools to understand the impact of human activities in natural ecosystems. The aim of this work was to study the water quality of two estuarine lakes in Santa Catarina, Brazil (Camacho Lake and Santa Marta Lake). Geophagus brasiliensis is a species widely distributed in Brazil and was used in this work. Comet assays in peripheral red blood and kidney cells, micronucleus tests in peripheral red blood cells, measurements of acetylcholinesterase activity in axial muscle and histopathological analysis of liver were used as biomarkers. Three sampling campaigns were undertaken in November 2004, June 2005 and November 2005. Thirty adult animals were sampled from each of three different sites (P1—Santa Marta Lake, P2 and P3—Camacho Lake). A negative control was sampled in a non-polluted site at Costa Ecological Park, Paraná. The positive control for genotoxicity was obtained by treating animals with copper sulphate. The results showed that both studied lakes are impacted by potential genotoxic substances. Severe lesions in liver of G. brasiliensis were also observed. The inhibition of acetylcholinesterase activity suggests the presence of pesticides or metals in the studied sites. This work shows that the water quality of Santa Marta and Camacho Lakes have been compromised and further control source of pollutants into these ecosystems is required.  相似文献   
326.
Mercury emissions from some upstream gold mining areas and recent findings of high natural Hg levels in sediments motivated studies on the Hg cycle in the Minas Gerais state. The study presents the total mercury amount found in Geophagus brasiliensis' muscular tissue (wet weight) and sediments from Piracicaba River. Mercury was analyzed using acid digestion followed by determination of total mercury by cold vapour atomic absorption spectrophotometry. This study was also complemented with the analysis of the limnological parameters (water temperature, conductivity, total dissolved solids, suspended particles, pH, dissolved oxygen, maximum depth, photic index and total carbon). The mercury concentration in sediments samples was higher than the mercury concentration in muscular tissue of fish. The lowest Hg level measured in fish was 0.0147 microg g( - 1), while the highest was 0.101 microg g( - 1). In the sediment samples, the lowest and highest levels were 0.02 microg g( - 1) and 0.16 microg g( - 1), respectively. The Hg concentrations in fish and sediment were both under the maximum limit permitted by the World Health Organization.  相似文献   
327.
Lead (Pb) has been highlighted as a major pollutant of both terrestrial and aquatic ecosystems, causing negative impacts to these environments. The concentration of Pb in plants has increased in recent decades, mainly due to anthropogenic activities. This study has as a hypothesis that the species Oxycaryum cubense (Poep. & Kunth) Palla, abundant in aquatic environments, has the potential to be used a phytoremediator. The plants were grown in a hydroponic system with Pb in increasing concentrations (0, 4, 8, 16 and 32 mg l?1) for 15 days. Inductively coupled mass spectrometer (ICP OES) was used to determine the concentration of mineral nutrients and lead. Optical and transmission electron microscopy were used for the analysis of cellular damage induced by lead in roots and leaves. Ultrastructural alterations were observed as disorganization of thylakoids in the chloroplast and disruption of mitochondrial membranes in cells of leaf tissues of plants subjected to increasing Pb concentrations. There was accumulation of Pb, especially in the root system, affecting the absorption and translocation of some mineral nutrients analysed. In roots, there was reduction in the thickness of the epidermis in plants treated with Pb. This species was shown to be tolerant to the Pb concentrations evaluated, compartmentalizing and accumulating Pb mainly in roots. Due to these results, it may be considered a species with phytoremediation capacity for Pb, with potential rizofiltration of this metallic element in contaminated watersheds.  相似文献   
328.
This study presents information on the use of medicinal animals in a semiarid area of northeast Brazil, a region where animals have recognized importance in local popular medicine. The information on the use of animals for medicinal purposes was obtained through semi-structured questionnaires, complemented by free interviews and informal conversations. The results obtained showed that the residents of the area studied utilize a considerable richness of animal species (n = 42) for medicinal purposes, as occurs in other areas of Brazil’s semiarid region, demonstrating that zootherapy represents an alternative form of health care that is important to the inhabitants of the region. There is a need for new investigations on medicinal fauna, aimed at promoting the sustainable use of eventual medicinal species and preserving popular knowledge associated with the use of animal species.  相似文献   
329.
In the present study, selected advanced oxidation processes (AOPs)—namely, photo-Fenton (with Fe2+, Fe3+, and potassium ferrioxalate—FeOx—as iron sources), solar photo-Fenton, Fenton, and UV/H2O2—were investigated for degradation of the antineoplastic drug mitoxantrone (MTX), frequently used to treat metastatic breast cancer, skin cancer, and acute leukemia. The results showed that photo-Fenton processes employing Fe(III) and FeOx and the UV/H2O2 process were most efficient for mineralizing MTX, with 77, 82, and 90 % of total organic carbon removal, respectively. MTX probably forms a complex with Fe(III), as demonstrated by voltammetric and spectrophotometric measurements. Spectrophotometric titrations suggested that the complex has a 2:1 Fe3+:MTX stoichiometric ratio and a complexation constant (K) of 1.47 × 104 M–1, indicating high MTX affinity for Fe3+. Complexation partially inhibits the involvement of iron ions and hence the degradation of MTX during photo-Fenton. The UV/H2O2 process is usually slower than the photo-Fenton process, but, in this study, the UV/H2O2 process proved to be more efficient due to complexing of MTX with Fe(III). The drug exhibited no cytotoxicity against NIH/3T3 mouse embryonic fibroblast cells when oxidized by UV/H2O2 or by UV/H2O2/FeOx at the concentrations tested.  相似文献   
330.
We evaluated 41 rural workers occupationally exposed to pesticides and 32 subjects as a control group, using the micronucleus (MN) and the comet assay. For the comet assay, we evaluated the peripheral blood, and for the MN, we sampled cells from the oral epithelium. Damage to DNA was measured by tail length, % DNA in tail (% tail), olive tail moment (OTM), and tail moment (TM). The exposed group presented an 8× increase in MN frequency, when compared to the control group (p <0.05). When we contrasted the MN frequencies between the individuals that use and do not use personal protective equipment, we found a mean of 7.5 MN (57 % variance) and 12.1 MN (130 % variance), respectively. The binucleated cells were 0.04 and 0.005, in the exposed and control groups, respectively, indicating 8× increase in the number of binucleated cells, when comparing the groups (p <0.05). In the comet assay, we demonstrated statistically significant differences in three parameters (% DNA, OTM, and TM) indicating that the rural workers presented high levels of genomic damages. Our results indicate that occupational exposure to pesticides could cause genome damage in somatic cells, representing a potential health risk to Brazilian rural workers that deal constantly with agrochemicals without adequate personal protection equipment.  相似文献   
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