F. S. Tagliaferro

Pathway of rare-earth elements in a Brazilian forestry fragment

The Mata de Santa Genebra is a fragment of semi-deciduous tropical forest located in an urban area of Sao Paulo State, Brazil. Potential sources of rare-earth elements (REE), such as oil refinery, agricultural activities and high-traffic roads, are situated close to this region. In this study, the central portion of the fragment dominated by Pachystroma longifolium and Esenbeckia leiocarpa was evaluated for the distribution of La, Ce, Nd, Sm, Eu, Tb and Yb in the soil, leaf and litter sub-compartments applying instrumental neutron activation analysis (INAA). Leaf/soil concentration ratios (CR) of P. longifolium were higher than those obtained for E. leiocarpa by a factor of 20. Considering leaf/litter concentration ratios, no retranslocation of these elements was noticed for both species before litterfall. Accumulation of REE and typical distribution patterns were observed for the plant sub-compartments. The high La content may be attributed to preferential uptake by these plants or to external atmospheric sources.

Informational Asymmetry in the Brazilian Orange Juice Market

Certification, labeling, standardization, traceability, and origin seals take part of a context where the information plays a key role for the guarantee of food safety. However, the available information about food quality attributes is frequently imperfect to consumers, producers, and industry. In the agri-food chain, the consumer is the actor with the lowest degree of information. The main qualitative-quantitative variables of the juice characteristics from different production systems were confronted with an analysis of the consumer perception, in order to clarify the main questions related to the quality of different types of orange juice. The research (185 questionnaires) carried out with consumers of orange juice in the campus “Luiz de Queiroz,” University of São Paulo, Piracicaba, São Paulo state, Brazil, showed that the majority of consumers consider that the information on the labels is not clear. Moreover, about 70% of the interviewed participants did not know the difference between orange juice and nectar. The main reason for consumption of orange juice was the flavor and the main reason for buying a specific brand was the price. The results suggest that the orange juice industries practice an opportunistic attitude, taking advantage of the fact that the consumer is unaware of the legal definition of nectar, different types of orange juices, and information on the labels of different orange juices and nectars.

Survey of lanthanoids in plants from a tropical region

Several anthropogenic sources may provide lanthanoids (La, Ce, Nd, Sm, Eu, Tb and Yb) to the agricultural and forestry landscapes. Because little information is available on the distribution of these chemical elements in Brazilian tropical ecosystems, this work focuses on the survey in leaves of diverse plant species (native trees, epiphytes and crops) from different ecosystems. Soil under crown projection was also analysed, thereby estimating the influence of its chemical composition on accumulation in leaves. The degree of lanthanoids accumulation varied substantially even for species growing in the same habitat. The most accumulator species, Alsophila sternbergii, presented the typical distribution pattern for lanthanoids, different from Pachystroma longifolium, a native species from the urban fragment, and the cultivated Citrus sp., in which the altered patterns revealed lanthanum enrichment in spite of cerium depletion in the leaves.

Tobacco Element Composition Determined by INAA

Inorganic components were surveyed of some Brazilian cigarette tobacco by INAA. Sixteen different brands were taken from the consumer market and analyzed for As, Ba, Br, Ca, Ce, Co, Cr, Cs, Eu, Fe, K, La, Na, Rb, Sc, Sm, Sr and Zn elements. Comparisons between the results from this work and those originated from several cigarette tobacco producing countries, indicate significant variation in the levels of some elements.

Characterisation of Components of Waste Rock Piles of Future Uranium Mining Activities in Brazil Using INAA and Statistical Data Treatment

In a preliminary study performed with the waste rocks from the future uranium mine to be explored in Brazil, 106 samples were taken from the eight main lithologies found in the massif and analysed by instrumental neutron activation analysis (INAA) for 20 elements. For samples from the same lithology, a high variability in the concentration of most of the elements was found (coefficient of variation larger than 20%), which might be attributed to either insufficient homogenisation of minerals or to local variation within lithology. The hypothesis that the variability within the lithology does not have an influence to the total variability was tested by analysing 5 replicates of the 5 most contrasting samples from the predominant lithology (plagioclase-microcline-gneiss), chosen after applying statistical evaluation (principal components and cluster analyses). Results indicated that homogenisation of samples was adequate due to low variation among replicates. The hypothesis tested was rejected with a confidence level higher than 99% for all the elements, corroborating the large intra-lithology variability.

Environmental control in the uranium mine Lagoa Real, Brazil.

Uranium production in Brazil will be restarted in the year 2000, through exploration of the Jazida da Cachoeira, located in the uraniferous region of Lagoa Real, Bahia State, northeast Brazil. Because of the mining operations, an open cast mine of approximately 27 × 104 m2 will be produced and the material removed will constitute approximately 14 x 106 tons, occupying an estimated area of 50 x 104 m2. Currently, there is a new concept about project developing, where the impact assessment is addressed during the initial phases. Beside this, legislation requires an environmental impact assessment before starting mining activities. In this context purpose, it is the purpose of this work to evaluate the chemical composition of the future waste; thus, samples were collected from the rocks that surround the mineral deposits. Instrumental neutron activation analysis was used for the elemental quantification, the mean elemental concentrations were calculated, and the ratios were normalized using North American Shale Composite (NASC). In the raw material eight main mineral structures exist whose elementary composition were compared using the statistical techniques of analysis of variance, ranking ANOVA, and multivariate ANOVA.