Detection of rare-earth elements using fiddler crabs Leptuca leptodactyla (Crustacea: Ocypodidae) as bioindicators in mangroves on the coast of São Paulo, Brazil.

Rare-earth elements have gained significant attention as they are currently widely used in high tech, chemical, and pharmaceutical industries. Here we used the fiddler crabs Leptuca leptodactyla as bioindicators to verify the presence of rare-earth elements in two mangrove areas of the Ubatuba, northern littoral of São Paulo state, Brazil. The specimens were collected in the mangrove areas of the Tavares River and Quiririm-Puruba river system, separated by season (dry and rainy). A total of 243 individuals were collected and analyzed. For determination and quantification of the elements we used the instrumental neutron activation analysis (INAA) technique. In both the dry and rainy season, the elements La, Ce, Sm, Eu, Tb, Yb and Sc were detected in samples of both mangroves, with La and Ce presenting higher concentrations. Samples from Tavares River mangrove had higher concentration levels of rare-earth elements than those of the Quiririm-Puruba river system. That is probably due to the central geographic position of the Tavares River in Ubatuba, which crosses a large portion of the city and receives a great amount of sewage. On the other hand, the Quiririm-Puruba river system has less anthropogenic inputs, thus, it receives much fewer rare-earth elements when compared to the Tavares River.

Tillandsia usneoides: A successful alternative for biomonitoring changes in air quality due to a new highway in São Paulo, Brazil.

Tillandsia usneoides is an aerial epiphytic bromeliad that absorbs water and nutrients directly from the atmosphere by scales covering its surface. We expanded the use of this species as a broader biomonitor based on chemical and structural markers to detect changes in air quality. The usefulness of such comprehensive approach was tested during the construction and opening of a highway (SP-21) in São Paulo State, Brazil. The biomonitoring study was performed from 2009 to 2012, thus comprising the period during construction and after the highway inauguration. Metal accumulation and structural alterations were assessed, in addition to microscopy analyses to understand the metal chelation in plant tissues and to assess the causes of alterations in the number and shape of scale cells. Altogether, our analyses support the use of this species as a wide biomonitor of air quality in urbanized areas.

ESR dating of Smilodon populator from Toca de Cima dos Pilão, Piauí, Brazil.

Smilodon is a genus of big cats that lived from the early to the late Pleistocene in regions extending from North to South America. The fossil records of the "saber-toothed cats" are uneven, with some taxa being quite abundant in certain regions. In Brazil, Smilodon populator is a well-known species whose remains, although scarce in comparison to other large mammals, are found all across the country. In particular, there are multiple records of this species in the region of the Serra da Capivara National Park. This area was home to a rich Pleistocene-Holocene fauna, including many mammals. Here, we report on the Electron Spin Resonance dating of a Smilodon populator tooth found in "Toca de Cima dos Pilão", located in the surroundings of the Serra da Capivara National Park. The equivalent dose found after exponential fitting of dose-response curve was (2.7±0.3)x102Gy. Neutron Activation Analysis was used to determine the concentration of radioisotopes present in the sample and in the sediment to calculate the internal and external dose rates. The result of age found is 93±9ka, which confirmed the presence of this species in Serra da Capivara National Park in the late Pleistocene.

Electron Spin Resonance Dating of Toxodon Tooth from Upper Ribeira Valley, São Paulo, Brazil.

Electron spin resonance (ESR) dating was applied to date a sample of fossil tooth found in Ribeira Valley, São Paulo, Brazil. This region is characterized by abundant fossil records of Pleistocene-Holocene South American megafauna belonging to different faunistic moments related to climate changes during the quaternary. As the number of fossils dated is not too large, the dating of materials from this region will provide important information to better understand the events associated with the presence and extinction of these species. The equivalent dose (De) was determined using single exponential fitting resulting in (24 ± 1)Gy. The De was converted to age using ROSY ESR Dating program and the concentration of radioisotopes present in the sample and soil determined through neutron activation analysis. The ages cover the range of 25-34 ka. This information is important to contextualize other findings in the region from different sites and to help obtain better information about the climate changes in this region.

Dating of fossil human teeth and shells from Toca do Enoque site at Serra das Confusões National Park, Brazil.

This work reports the dating of a fossil human tooth and shell found at the archaeological site Toca do Enoque located in Serra das Confusões National Park (Piauí, Brazil). Many prehistoric paintings have been found at this site. An archaeological excavation unearthed three sepulchers with human skeletons and some shells. Two Brazilian laboratories, in Ribeirão Preto (USP) and Recife (UFPE), independently performed Electron Spin Resonance (ESR) measurements to date the tooth and the shell and obtain the equivalent dose received by each sample. The laboratories determined similar ages for the tooth and the shell (~4.8 kyBP). The results agreed with C-14 dating of the shell and other samples (charcoal) collected in the same sepulcher. Therefore, this work provides a valid inter-comparison of results by two independent ESR-dating laboratories and between two dating methods; i.e., C-14 and ESR, showing the validity of ESR dating for this range of ages.

Tillandsia usneoides: a successful alternative for biomonitoring changes in air quality due to a new highway in São Paulo, Brazil.

Tillandsia usneoides is an aerial epiphytic bromeliad that absorbs water and nutrients directly from the atmosphere by scales covering its surface. We expanded the use of this species as a broader biomonitor based on chemical and structural markers to detect changes in air quality. The usefulness of such comprehensive approach was tested during the construction and opening of a highway (SP-21) in São Paulo State, Brazil. The biomonitoring study was performed from 2009 to 2012, thus comprising the period during construction and after the highway inauguration. Metal accumulation and structural alterations were assessed, in addition to microscopy analyses to understand the metal chelation in plant tissues and to assess the causes of alterations in the number and shape of scale cells. Altogether, our analyses support the use of this species as a wide biomonitor of air quality in urbanized areas.

Searching for native tree species and respective potential biomarkers for future assessment of pollution effects on the highly diverse Atlantic Forest in SE-Brazil.

This study summarizes the first effort to search for bioindicator tree species and respective potential biomarkers for future assessment of potential mixed pollution effects on the highly diverse Atlantic Forest in SE-Brazil. Leaves of the three most abundant species inventoried in a phytosociological survey (Croton floribundus, Piptadenia gonoacantha and Astronium graveolens) were collected in four forest remnants during winter and summer (2012). Their potential bioindicator attributes were highlighted using a screening of morphological, chemical and biochemical markers. The leaf surface structure and/or epicuticular wax composition pointed the accumulator properties of C. floribundus and P. gonoacantha. C. floribundus is a candidate for assessing potential accumulation of Cu, Cd, Mn, Ni, S and Zn. P. gonoacantha is a candidate to monitor polycyclic aromatic hydrocarbons. Increased levels of secondary metabolites and decreased antioxidant capacity in leaves of A. graveolens may support its value as a bioindicator for oxidative pollutants by visible dark stipplings.

Dating human occupation at Toca do Serrote das Moendas, São Raimundo Nonato, Piauí-Brasil by electron spin resonance and optically stimulated luminescence.

Excavation of Toca do Serrote das Moendas, in Piauí state, Brazil revealed a great quantity of fossil wild fauna associated with human remains. In particular, fossils of a cervid (Blastocerus dichotomus) were found, an animal frequently pictured in ancient rock wall paintings. In a well-defined stratum, two loose teeth of this species were found in close proximity to human bones. The teeth were independently dated by electron spin resonance (ESR) in two laboratories. The ages obtained for the teeth were 29 ± 3 ka (thousands of years) and 24 ± 1 ka. The concretion layer capping this stratum was dated by optically stimulated luminescence (OSL) of the quartz grains to 21 ± 3 ka. As these values were derived independently in three different laboratories, using different methods and equipment, these results are compelling evidence of early habitation in this area.

Electron spin resonance dating of megafauna from Lagoa dos Porcos, Piauí, Brazil.

Excavations performed at Lagoa dos Porcos site revealed a vast amount of extinct mammal fossil remains, becoming one of the richest palaeontological occurrences in the Serra da Capivara National Park region, a UNESCO World Heritage. Although anatomic and taxonomic aspects of extinct Quaternary mammals are relatively well known, chronologic information for deposits is rare. In this context, electron spin resonance (ESR) dating of megafauna samples provides important information for establishing a chronological background. This work presents the ESR dating of two teeth, one of Gomphotheriidae and other of Toxodontinae. Dose-response curves of each sample were constructed using spectra acquired with a JEOL FA-200 X-Band spectrometer resulting in equivalent dose (De) of 220 ± 40 Gy and 39 ± 2 Gy for Toxodontinae and Gomphotheriidae tooth, respectively. The conversion of De in age was made using ROSY ESR dating software resulting in 26 ± 4 and 22 ± 3 ka. These results place Lagoa dos Porcos fossil assemblage within the Late Pleistocene. These dates overlap with a period of abrupt increase in rainfall in northeast Brazil, and it is possible that this environmental change is related to the formation of this deposit.

Combined SEM/AVS and attenuation of concentration models for the assessment of bioavailability and mobility of metals in sediments of Sepetiba Bay (SE Brazil).

This study proposes a new methodology to study contamination, bioavailability and mobility of metals (Cd, Cu, Ni, Pb, and Zn) using chemical and geostatistics approaches in marine sediments of Sepetiba Bay (SE Brazil). The chemical model of SEM (simultaneously extracted metals)/AVS (acid volatile sulfides) ratio uses a technique of cold acid extraction of metals to evaluate their bioavailability, and the geostatistical model of attenuation of concentrations estimates the mobility of metals. By coupling the two it was observed that Sepetiba Port, the urban area of Sepetiba and the riverine discharges may constitute potential sources of metals to Sepetiba Bay. The metals are concentrated in the NE area of the bay, where they tend to have their lowest mobility, as shown by the attenuation model, and are not bioavailable, as they tend to associate with sulfide and organic matter originated in the mangrove forests of nearby Guaratiba area.

Bioindication of atmospheric trace metals--with special references to megacities.

After considering the particular problems of atmospheric pollution in megacities, i.e. agglomerations larger than 5 mio. inhabitants, with urbanization of World's population going on steadily, possibilities of active biomonitoring by means of green plants are discussed. Based on specific definitions of active and passive bioindication the chances of monitoring heavy metals in Sao Paulo megacity were demonstrated (first results published before). This is to show that there is need for increased use of bioindication to tackle the particular problems of megacities concerning environmental "health", the data to be processed according to the Multi-Markered-Bioindication-Concept (MMBC). Comparison to other work shows this approach to be reasonable.

Vigilância sanitária no Brasil / Health surveillance in Brazil

Mostra o percurso que foi necessário à sociedade brasileira para que a vigilância sanitária ocupasse, ao lado de outros campos da saúde coletiva, um espaço importante na garantia do direito à saúde e de cidadania.(AU)

ESR dating at K and X band of northeastern Brazilian megafauna.

The archaeological dose (AD) was measured in three tooth samples of giant mammals that belonged to Brazilian megafauna using electron spin resonance (ESR) spectroscopy at X-band (nu approximately 9.5 GHz) and K-band (nu approximately 24 GHz). Samples were collected in Lagoa de Dentro, Puxinanã city in Paraiba, a northeast state in Brazil and were identified as Haplomastodon waringi (Holland) (two teeth) and one tooth sample of Xenorhinotherium bahiense (Cartele and Lessa). The average AD led to an age for the Haplomastodon samples of 11.6 ky bp. For one sample (Haplomastodon) K-band was also employed to evaluate the AD. The K-band spectrum had three components, determined using spectral simulation as follows: a wide isotropic line with g factor 2.0048, an orthorhombic line with g(x)=2.0034, g(y)=2.0022 and g(z)=1.9974, and another isotropic line with g factor 2.0008. The amplitude of these three signals increase with the added dose and the average dose found was 26+/-5 Gy. This result is compatible with the AD determined with X-band 21+/-3 Gy.