Experimento didático sobre cromatografia gasosa: uma abordagem analítica e ambiental

This paper describes an experiment to teach the principles of gas chromatography exploring the boiling points and polarities to explain the elution order of a series of alcohols, benzene and n-propanone, as well as to teach the response factor concept and the internal standard addition method. Retention times and response factors are used for qualitative identification and quantitative analysis of a hypothetical contamination source in a simulated water sample. The internal standard n-propanol is further used for quantification of benzene and n-butanol in the water sample. This experiment has been taught in the instrumental analysis course offered to chemistry and oceanography students.

A novel disposable electrochemical microcell: construction and characterization

An alternative technique for the fabrication of disposable electrochemical microcells containing working, reference and auxiliary electrodes on a single device is reported. The procedure is based on thermal-transfer of toner masks onto CD-R (recordable compact discs) gold surfaces to define the layout of the electrodes (contour). In a subsequent step, the layout is manually painted with a permanent marker pen. The unprotected gold surface is conveniently etched (chemical corrosion) and the ink is then easily removed with ethanol, generating gold surfaces without contamination. The final and reproducible area of the electrodes is defined by heat transference of a second toner mask. Silver epoxy is deposited on one of the gold bands which is the satisfactorily used as reference electrode. These microcells were electrochemically characterized by cyclic, linear, and square wave voltammetry, and several electroactive species were used as model systems. The area reproducibility of the electrodes for different microcells was studied and a relative standard deviation better than 1,0% (n = 10) was obtained. Disposable electrochemical microcells were successfully used in analysis of liquid samples with volumes lower than 200 µL and good stability and reproducibility (RSD less than 2.0%) were achieved. These microcells were also evaluated for quantification of paracetamol and dipyrone in pharmaceutical formulations.

Avaliação da contaminação por elementos metálicos dos sedimentos do Estuário Santos - São Vicente

Three approaches were applied to evaluate metal contamination in 41 sediment samples from the Santos - São Vicente Estuarine System: normalization to Al, statistical analysis and sediment quality guidelines (SQGs). The results showed increases in the concentrations of Zn, Ni, Pb, Cd, Cr and Hg, which seemed to be associated with human activities. The levels of Al, Fe and Co probably were associated with crustal material or natural weathering processes. About 45% of the samples presented concentrations exceeding TEL-ERL, levels occasionally associated with adverse biological effects. Four of these samples presented concentrations above PEL-ERM, levels frequently associated with adverse biological effects.

Hematological analysis of Micropogonias Furnieri, Desmarest, 1823, Scianidae, from two estuaries of Baixada Santista, São paulo Brazil

Hematological alterations in fish are considered a useful tool to evaluate pathological processes resulting from the exposure to environmental pollutants. The whitemouth croaker Micropogonias furnieri is a common species in estuarine areas and potentially exposed to many contaminants. In the present study, the hematological characteristics of fish collected at two sites in Baixada Santista (Santos Estuarine System - SES, a polluted site; and the Estuary of Itanhaém River - EIR, unpolluted site) del was analysed. The following blood descriptors were analyzed: number of Erythrocytes (Er), Hematocrit (Ht), Hemoglobin (Hb), Mean Corpuscular Volume (MCV) and Mean Corpuscular Hemoglobin concentration (MCHC). Fish from SES exhibited significant lower levels of Ht and increase on MCHC and Hb. Such differences are likely related to the different contamination levels found in these estuaries.

Marcadores orgânicos de contaminação por esgotos sanitários em sedimentos superficiais da baía de Santos, São Paulo

Organic markers, such as sterols and ketones, were used to assess sewage contamination in sediments from the Santos Bay, SP, and its continental shelf. These compounds were analyzed by GC/FID after soxhlet extraction, clean up and derivatization. The concentration of coprostanol and ratios between selected sterols were used to evaluate fecal contamination. The stations located in the mid-western part of the Santos Bay presented organic matter from sewage due to the input of fecal material from the city of Santos by submarine sewage outfall. Stations located at the continental shelf did not present fecal contamination. Coprostanol levels in sewage outfall stations were higher in comparison to other Brazilian coastal areas, except Guanabara Bay/RJ, and could be related to the fraction of the population without sewage treatment.

Microbiological quality of hamburgers sold in the streets of Cuiabá - MT, Brazil and vendor hygiene-awareness

This study evaluated the microbiological quality of hamburgers and the microbe community on the hands of vendors in Cuiabá, Mato Grosso, Brazil, in relation to vendors´ awareness as to what constitute acceptable food-handling practices as part of a broad-spectrum research programme on street foods in Brazil . Sale of the hamburger known as the 'baguncinha' is common and widespread in urban Cuiabá, Mato Grosso, Brazil. Food inspectors encounter various difficulties in carrying out inspections. One hundred and five hamburgers samples were evaluated using conventional methods including tests for facultative aerobic and/or anaerobic mesophytic bacteria, coliform counts at 45 °C, the coagulase test for Staphylococcus, Gram-staining for the presence of Bacillus cereus, Clostridium sulphite reductase and Salmonella spp. The hamburgers were categorized as unsuitable for human consumption in 31.4% of samples, with those testing positive for coliforms and Staphylococcus at unacceptably high levels by Brazilian standards. High levels of microbiological contamination were detected on the hands of the food handlers and mesophytic bacterial counts reached 1.8 × 10(4) CFU/hand. Interviews were carried out by means of questionnaires to evaluate levels of awareness as to acceptable food handling practices and it was found that 80,1% of vendors had never participated in any kind of training.

Protocol for DNA extraction of Cryptosporidium spp. oocysts in fecal samples

Molecular characterization of Cryptosporidium spp.oocysts in clinical samples is useful for public health since it allows the study of sources of contamination as well as the transmission in different geographical regions. Although widely used in developed countries, in Brazil it is restricted to academic studies, mostly using commercial kits for the extraction of genomic DNA, or in collaboration with external reference centers, rendering the method expensive and limited. The study proposes the application of the modifications recently introduced in the method improving feasibility with lower cost. This method was efficient for clinical samples preserved at -20 °C for up to six years and the low number of oocysts may be overcomed by repetitions of extraction.

Impactos na saúde das deficiências de acesso a água

O acesso regular à água potável e segura tem causado preocupação, principalmente em países em desenvolvimento e, mais enfaticamente em áreas periurbanas, que abrigam a população socialmente excluída. O objetivo deste trabalho é abordar questões de acesso à água em regiões periurbanas e para tanto foi realizado levantamento bibliográfico nas bases de dados Pubmed, Medline e SciELO assim como relatórios da OMS, OPAS, IBGE e Ministério das Cidades. A falta ou a precariedade do acesso à água representa situação de risco que propicia aumento da incidência de doenças infecciosas agudas e da prevalência de doenças crônicas. O estabelecimento do grau de acesso à água de qualidade considera fatores como distância e tempo percorrido até a fonte de água, volume coletado, demanda atendida e nível de prioridade de ações de intervenção. Na qualidade da água, consideram-se como fatores de impacto o manuseio - maneira como ocorre a coleta, o transporte, o armazenamento e o uso -, a presença de patógenos nas fontes e as práticas rotineiras da população. A determinação da presença de patógenos nas fontes evidencia o risco à saúde e a identificação do agente etiológico indica a origem da contaminação. O caminho para reverter esse cenário é a implementação integrada de políticas públicas de gestão, que envolvam ações conjuntas e ajustadas nos setores de desenvolvimento urbano, habitação, saneamento e saúde e que visem à promoção e à proteção da saúde da população local e ao enfrentamento da complexidade de fatores que evidenciam sua vulnerabilidade.

Etiologic diagnosis of bovine infectious abortion by PCR

Infectious abortion is a significant cause of reproductive failure and economic losses in cattle. The goal of this study was to detect nucleic acids of several infectious agents known to cause abortion including Arcanobacterium pyogenes, Bovine Herpesvirus 1, Brucella abortus, Campylobacter fetus subsp. venerealis, Chlamydophila abortus, Leptospira sp., Listeria monocytogenes, Salmonella sp., Mycoplasma bovis, Mycoplasma bovigenitalium, Neospora caninum, and Tritrichomonas foetus. Tissue homogenates from 42 fetuses and paraffin-embedded tissues from 28 fetuses and 14 placentas/endometrium were included in this study. Brucella abortus was detected in 14.2% (12/84) of the samples. Salmonella sp. DNA was amplified from 2 fetuses, and there was one positive for Neospora caninum, and another for Listeria monocytogenes. This PCR-based approach resulted in identification of the etiology in 19% of samples, or 20% if considered fetal tissues only.

EMJH medium with 5-fluorouracil and nalidixic acid associated with serial dilution technique used to recover Leptospira spp from experimentally contaminated bovine semen

Bovine semen experimentally contaminated with Leptospira santarosai serovar Guaricura was submitted to the modified EMJH medium with 5-fluorouracil (300mg/L) and nalidixic acid (20mg/L), named as "selective medium" and using the serial dilution technique, in order to evaluate the percentage of recovery of the added microorganism. The selective EMJH medium was found with higher percentage of recovery of leptospiras and minor losses of samples due to contamination with opportunistic microorganisms than the non-selective EMJH medium: 151/376 (40.0%) of positive growth; and 38/376 (10.0%) contamination and 58/376 (15%) and 129/376 (34.0%), respectively. These results were statistically significant (p<0. 0001; Fisher). Differences were found when the frequencies of positive leptospires recovery have been compared in the serial dilution technique (10-1 to 10-4) between the selective and non-selective media at different dilution factors. At 1/10th dilution the percentages found were (0%, 0/80) and (38%, 30/80), at 1/100th dilution, (3%, 2/80) and (49%, 39/80) and at 1/1,000th dilution, (25%, 20/80) and (50%, 40/80), respectively. The percentage of recovery of leptospires was found to be directly proportional to the dilution used. The methodology of the serial dilution technique (setting at least three dilutions) and the use of selective EMJH medium have been found to be efficient for the isolation of leptospires from the bovine semen samples.

Comparison of three decontamination methods for Mycobacterium bovis isolation

Sixty samples of tissue fragments with lesions suggestive of tuberculosis from bovine abattoirs, kept in saturated solution of sodium borate, were subjected to four treatments: 4% NaOH (Petroff Method), 12 % H2SO4 and 1.5% HPC (1-Hexadecylpyridinium Chloride) decontamination, and physiological saline solution (control). The HPC method showed the lowest contamination rate (3%) when compared to control (88%, p<0.001), NaOH (33%, p<0.001) and H2SO4 (21.7%, p<0.002). Regarding the isolation success, the HPC method was better (40%) than the control (3%, p<0.001), NaOH (13%, p=0.001) and H2SO4 (1.7%, p<0.001) methods. These results indicate that HPC is an alternative to the Petroff method.

Evaluation of the efficacy of hydrated sodium aluminosilicate in the prevention of aflatoxin-induced hepatic cancer in rainbow trout

The use of aluminum silicates for decontaminating animal feed containing aflatoxins has yielded encouraging results in chicken and turkey poults. In contrast, very few studies have tested these substances in aquaculture. In this work, we investigated the efficacy of a trout diet containing 0.5% hydrated sodium aluminosilicate (HSAS) in protecting against contamination with aflatoxin B1. Trout were reared on these diets for one year and the experimental groups were examined monthly for hepatic presumptive preneoplastic and neoplastic lesions. Regardless of the presence of HSAS, all of the fish that received aflatoxin in their diet have shown hepatic lesions indicative of a carcinogenic process, presenting also the development of cancer in some fish. The concentration of HSAS used in this study was ineffective in preventing the onset of hepatic lesions induced by aflatoxin B1 in rainbow trout.

Riscos à saúde em áreas contaminadas: contribuições da teoria social

Este artigo versa sobre contribuições da teoria social a um estudo sobre o risco à saúde humana e ao ambiente, desenvolvido entre 2003 e 2005 em área urbana contaminada, localizada no bairro Vila Carioca, no sudeste do município de São Paulo, Brasil. Resíduos perigosos provenientes de processo produtivo do setor químico, dispostos inadequadamente na localidade ao longo do tempo, resultaram em contaminação ambiental, cujos efeitos representam riscos à saúde da população local. A investigação foi realizada com o objetivo de identificar interpretações sociais sobre o conceito de situação de risco, condizentes com concepções incorporadoras da dimensão social do risco e voltadas à melhoria das condições de saúde ambiental. Utilizou-se metodologia qualitativa de pesquisa, alicerçada na teoria social, e instrumentos variados de coleta de dados. Os resultados apontaram interpretações sociais diferenciadas sobre o conceito de situação de risco, sugerindo diversidade de concepções entre a população pesquisada a respeito dos problemas ambientais e de saúde que os atingiam. Neste artigo, apresentam-se fundamentos do enfoque do risco, na teoria social e na obra de Ulrick Beck sobre sociedade de risco, a fim de conferir suporte teórico à interpretação dos dados coletados em campo. Tais contribuições da teoria social, em contraponto com abordagens multidisciplinares e ecossistêmicas em saúde e ambiente, são discutidas como forma de incorporar a diversidade de interpretações sociais expressadas pela população, no sentido de favorecer a inter-relação entre portadores de risco e decisões políticas locais sobre a questão do risco, ampliar o escopo dos fenômenos observados e propiciar a busca de melhores condições de saúde dos indivíduos e da qualidade do seu ambiente

Contaminated sites and brownfield management State of art in Brazil and in Germany

Purpose - The aim of this paper is to briefly present aspects of public brownfield management policies from Brazilian and German points of view. Design methodology approach - The data collection method combined literature and documental research. The bibliography included Brazilian and German literature about brownfield management. The documental research includes Brazilian and German legislation and official documents published by CETESB, the Environmental Company of the State of São Paulo, Brazil. Furthermore, publications of German governmental research institutions have been integrated in the paper. Findings - In Brazil, despite the lack of a federal public policy, the State of São Paulo has approved specific rules to deal with contaminated sites. Topics that could be targets of scientific studies have been identified. Experiences in Germany show that it is essential to have political will and cooperation between the different political levels and technical disciplines. Partnerships between German and Brazilian universities would be welcome as there is a wide range of opportunities for academic post-graduation studies and research focusing on human resources capacitation in environmental management. Originality value - The paper makes an original contribution of exploring an area (brownfield management) that is at the forefront of discussion in academe and industry

Proteção da comunidade aquática em efluente tratado por tanques de estabilização de resíduos no rio São Lourenço em São Lourenço da Serra, Vale do Ribeira, estado de São Paulo

O tratamento de esgotos de pequenas cidades por lagoas de estabilização é uma maneira simples, eficiente e de baixo custo. Os esgotos são uma fonte de contaminação das águas e solos e, conseqüentemente, contribuem para a transmissão de doenças, além de serem uma ameaça à preservação do meio ambiente. Surge a necessidade de investigar as condições dos efluentes lançados nos cursos d´água. O presente trabalho tem como objetivo realizar uma investigação da qualidade das águas residuárias tratadas por lagoas de estabilização de uma estação de tratamento de esgoto localizadas no município de São Lourenço da Serra no Vale da Ribeira no Estado de São Paulo e verificar os riscos sanitários e a comunidade aquática no Rio São Lourenço da Serra. Foram realizadas amostragens para avaliar o conjunto de lagoas anaeróbia e facultativa da estação de tratamento de esgoto do Município de São Lourenço da Serra. Os parâmetros utilizados foram pH, temperatura do ar e da água, condições climáticas, demanda bioquímica de oxigênio e nitrogênio amoniacal, bactérias termotolerantes, pigmentos fotossintéticos e comunidade zooplanctônica. Verificou-se que s sistemas de lagoa anaeróbia e facultativa foram eficientes na produção de efluente e apresentou alguns valores de acordo com a Resolução Conama nº 357, que estabelecem os valores limites para lançamento em corpos d´água. O rio São Lourenço está localizado em uma área de proteção ambiental. Os dados são comparados aos limites estabelecidos na Classe 1 e 2 e demonstram processo de eutrofização, colocando em risco à biodiversidade aquática e a saúde da população