Two traditional cosmetic clays bear similar names in different local South African languages: vumba (Tshivenda) and ubumba (isiZulu). The wet clays are applied topically for cosmetic purposes by the respective indigenous peoples. Six samples from two South African provinces were characterised using X-ray diffraction, X-ray fluorescence spectroscopy, Fourier transform infrared spectroscopy, thermal gravimetric analysis and scanning electron microscopy. It was found that the samples differed widely with respect to mineralogy and chemical composition. This finding raises the possibility that texture characteristics during application on the skin override composition effects. Of concern is the high levels of quartz found in all the samples as it might pose a health hazard; the lowest value for quartz was 11 wt% for vumba, while values for ubumba ranged from 26 wt% to 85 wt%. All samples contained varying amounts of silicates in the form of smectite, kaolin, chlorite and plagioclase. Minor amounts of anatase and rutile were present in some samples. Three samples also contained goethite. All samples were essentially free from the toxic elements As, Pb, Hg, Cd, Se and Sb. However, they did contain low levels of chromium and heavy metals such as Cu, Zn and Ni. The pH values of ubumba slurries were slightly basic, while those of a vumba slurry were slightly acidic. SIGNIFICANCE: • Wide ranges of composition appear to be acceptable. • The clays do not contain highly toxic or radioactive elements. • The high levels of quartz present may pose a human health risk.

O objetivo do trabalho foi avaliar o efeito de diferentes pontas de pulverização para aplicações terrestres em alta velocidade sobre a cobertura e depósito da pulverização em plantas de soja. Foram avaliadas as pontas de jatos planos AXI 110 04 à velocidade de 4,17 m.s-1 (testemunha), de jatos planos APE cinza e AXI 110 08, e de jatos planos duplos TD HiSpeed 110 06 e AXI TWIN 120 06, à velocidade de deslocamento de 9,72 m.s-1. O volume de aplicação foi fixado em 120 L.ha-1. A eficiência de aplicação foi avaliada por dois métodos: análise visual do percentual de cobertura, utilizando marcador fluorescente e com luz ultravioleta, e análise de depósito através da recuperação e da quantificação do marcador Azul Brilhante FD&C N°1 por espectrofotometria. Ambas as análises foram realizadas em amostras retiradas das partes superior, média e inferior das plantas. As pontas de pulverização mostraram padrões de cobertura e depósito diferenciados, de modo que, na parte superior, a cobertura foi favorecida por gotas mais finas e o depósito melhorado pelo uso de gotas médias. Nas demais partes da planta, não houve diferença estatística entre os tratamentos para cobertura e depósito. A velocidade de deslocamento não interferiu na eficiência da aplicação para pontas com o mesmo padrão de gota, sendo os níveis dos depósitos e da cobertura nos terços inferior e médio inferiores a 50% dos obtidos na parte superior das plantas.

The aim of this study was to evaluate different spray nozzles for land applications in high speed on the coverage and deposit in soybean plants pulverization. It was evaluated the AXI 110 04 plane jet nozzles operated at speed of 4.17m.s-1 (control), the grey APE and the AXI 110 08 plane jets, and the TD HiSpeed 110 06 and AXI TWIN 120 06 twin jets, at speed of 9.72m.s-1. The application volume was fixed in 120L ha-1. The application efficiency was evaluated by two different methods: analysis of the coverage area using fluorescent pigment and UV light and analysis of deposits through the recovery and quantification of FD&C N°1 brilliant blue marker by spectrophotometry. Both analyses were done in samples collected from top, middle and bottom parts of the plants. The spray nozzles showed differences in coverage and deposit pattern, so in the top part, the coverage was increased with smaller drops and the deposits were increased with medium drops. In the other parts of the plants, there were no statistical differences between the treatments for both coverage and deposits. The displacement speed did not influence the application efficiency for nozzles with the same drop pattern, and the obtained spray coverage and deposits at the medium and bottom parts of the plants were less than 50% of that found at the top of the soybean plants.

Avaliou-se a exposição humana ao metilmercúrio e ao mercúrio total em comunidades ribeirinhas do rio Tapajós e da região metropolitana de Belém, no Estado do Pará, Brasil, através da determinação de mercúrio total e metilmercúrio em amostras de cabelo nos anos de 1994 e 1995. Observou-se que as concentrações médias de mercúrio total variaram de 2 ± 1µg/g-1 a 20,5 ± 12,1µg/g-1, enquanto que as concentrações médias de metilmercúrio variaram de 1,4 ± 0,7µg/g-1 a 18,5 ± 11µg/g-1. Estes resultados confirmam a contaminação mercurial na região do rio Tapajós, admitem a possibilidade do aparecimento de sinais e sintomas de intoxicação mercurial e recomendam a manutenção da monitorização do mercúrio total e do metilmercúrio nas amostras de cabelo, bem como a necessidade de estudos clínico-epidemiológicos para implantação de medidas de prevenção e controle da intoxicação mercurial.

Evaluation of total human exposure to mercury and methylmercury was effected in riverine villages along the Tapajos river and in the metropolitan area of Belem city, state of Para, Brazil, by using total mercury and methylmercury concentrations in hair samples in 1994 and 1995. It was observed that average concentrations of total mercury are in a range from 2 ± 1µg/g-1 to 20.5 ± 12.1µg/g-1. While methylmercury average concentration varies from 1.4 ± 0.7µg/g-1 to 18.5 ± 11µg/g-1. These results confirm mercury contamination in the Tapajos river and possible appearance of mercury intoxication symptoms, and recommends the monitoring of compounds in hair samples as well as the need for epidemiological and clinical studies for human health prevention and control of mercury intoxication.

De uma casuística maior - 215 angiomas artériovenosos intracranianos, dos quais 118 submetidos à extirpação total - foram selecionados 54 pacientes com angiomas situados na região rolândica, nas regiões temporais e nos territórios limítrofes entre estas zonas e áreas cerebrais vizinhas. Dêsse grupo fôram estudados 22 casos nos quais o angioma artériovenoso estava localizado na região motora. A análise da motricidade e da capacidade de trabalho pós-operatória, após exerese total da lesão, mostrou que a localização da malformação nesta área de elevada importância funcional não aumenta o risco cirúrgico nem agrava o prognóstico. A cifra pré-operatória de perturbações da motricidade aumenta de modo passageiro no período pós-operatório imediato, mas volta a decair aos índices iniciais no período tardio. Qualitativamente, as deficiências motoras após a cirurgia são, em geral, menos intensas do que antes do tratamento. A capacidade integral de trabalho é conservada na maioria dos casos. Apenas uma porcentagem relativamente restrita de pacientes não apresenta integridade funcional completa depois da operação. Na nossa casuística, êste grupo era constituido precisamente por enfêrmos com angiomas de volume superior a 25 cm³. O único registro de invalidez se referiu a paciente que já estava hemiparética ao ser internada. Concluímos que a extirpação total é o método de escolha também no tratamento dos angiomas artériovenosos cerebrais situados em áreas ditas de elevada importância funcional e que eram consideradas inabordáveis sem grandes danos para a capacidade funcional do paciente.

Among 215 intracranial arteriovenous angiomas (118 submitted to total extirpation) 54 were located in the central region, in the temporal regions an in the transition territories between these and neighbouring cerebral areas. From this group 22 cases have been selected, in which the angioma was seated in the motor area. The study of the motor functions and of the postoperative working capacity in these patients has shown that the localisation of the malformation in this functionally important area does not increase the surgical risk, nor aggravates the prognosis for the patient. The postoperative incidence of motor disfunctions increases reversibly during the immediate postoperative period but later decreases again to the initial values. From the qualitative point of view the motor deficits observed after operation are usually less severe than before treatment. Full working capacity is retained in most cases. Only a relatively low percentage of patients does not display full working capacity after operation. In our casuistic this group was composed precisely of patients with angiomas larger than 25 cc. The only case of invalidity observed was that of a preoperatively already hemiparetic patient. Our conclusion is that total extirpation is the method of choice also for the treatment of those arteriovenous angiomas seated in cerebral areas considered of high functional importance.

In einer Kasuistik von 215 arteriovenösen Angiomen (118 Totalexstir-pationen) befanden sich die Angiome bei 54 Patienten in der Zentralregion, in den Temporalregionen und in den Übergangsgebieten zwischen diesen und den benachbarten Hirngebieten. Aus dieser Gruppe wurden 22 Fälle aus-gesucht, bei denen das arteriovenõse Angiom in der motorischen Gegend lag. Die Analyse der Motorik und der postoperativen Arbeitsfähigkeit bei diesen Fällen zeigte, dass die Lokalisation der Missbildung in diesem funk-tionell hochwertigen Gebiet das operative Risko nicht erhöht und die Prog nose für den Kranken nicht verschlechtert. Die präoperative Inzidenz von motorischen Ausfällen steigt sofort nach dem Eingriff voriibergehend an, aber sinkt in der katamnestischen Periode wieder auf die Anfangswerte ab. Qualitativ, jedoch, sind die motorischen Ausfälle nach der Operation im Allgemeinen weniger ausgeprägt als vor der Behandlung. Die Arbeitsfähigkeit bleibt in der Mehrzahl der Falle völlig erhalten. Nur ein relativ geringer Prozentsatz der Patienten ist postoperativ nicht võllig arbeitsfähig. In unserem Krankengut stellte sich diese Gruppe gera-de aus Patienten zusammen, deren Angiome ein grösseres Volumen als 25,0 cm³ hatten. Der einzige Fall von Invalidität war eine schon präopera-tiv hemiparetische Patientin. Es wird gefolgert, dass die Totalextirpation die Behandlungsmethode der Wahl darstellt, auch bei arteriovenösen Angiomen, die sich in funktionell hochwertigen Hirnbezirken befinden.