Metabolites in bile of fish from São Sebastião Channel, São Paulo, Brazil as biomarkers of exposure to petrogenic polycyclic aromatic compounds

This study reports the analysis of polycyclic aromatic compound (PAC) metabolites, as biomarkers of exposure to PACs in marine environment. PAC metabolites were measured in bile samples from 14 species of demersal fish caught in the São Sebastião Channel (SSC), SE Brazilian coastline. Naphthalene (NPH) equivalents, phenanthrene (PHN) equivalents, and benzo[a]pyrene (BaP) equivalents were quantified using a reverse-phase high-performance liquid chromatography coupled with fluorescence detection method. For all samples, the means (±standard deviation, n = 37) of concentrations obtained for NPH, PHN, and BaP equivalents were, respectively, 290,000 ± 200,000 ng/g, 18,000 ± 14,000 ng/g, and 970 ± 1900 ng/g. These results indicate recent exposure of these fish to PACs in their environment. In addition, two species (Cyclichthys spinosus and Prionotus nudigula) of fish were analyzed in order to investigate local sources of PAC contamination in the SSC and the influence of the petroleum terminal in fish caught in remote areas. The results showed that these fish species potentially migrate along the channel, especially P. nudigula. Correlations among groups of PAC metabolites indicate the same petrogenic source for NPH and PHN equivalents and a combustion source (e.g., automobile, ships) for BaP equivalents. The ratio BaP/PHN equivalents (0.05 ± 0.07, n = 37) confirms the predominance of petrogenic PACs for contamination by these chemicals in this region.     

Towards a spatial data infrastructure for technological disasters: an approach for the road transportation of hazardous materials

Spatial data have been used for the environmental monitoring of the consequences of accidents that involve the transportation of hazardous chemical products. This spatial data infrastructure (SDI), which was created for the sharing and use of spatial data, is limited by the absence of policies to support its establishment. The main objective of this study was to explore the use of social network analysis (SNA) as a tool to identify spatial data sharing between organizations involved in the management of accidents related to road transport of hazardous materials (RTHM). In addition, to discuss the existing policies and institutional agreements, and to initiate a conceptual SDI framework for RTHM sector. In this context, the institutions that are involved with RTHM were identified and information concerning their interest in the use and sharing of spatial data via a SDI was collected through interviews and consolidated. The interviews were at 39 institutions with representative employees. The interview data were tabulated and entered into the UCINET software (2000 version) to calculate metrics of centrality. From the SNA, the flow of data among the participating institutions was identified through the visual representation of the spatial data sharing and use networks. Subsequently, the existing institutional agreements for spatial data sharing were analyzed and discussed. The compiled results enabled the proposal of a conceptual SDI framework to support the management of disasters involving RTHM, based on the application of SNA theory, and the development of a methodology that supports the analysis of interactions among the various actors of an SDI. The purpose is to facilitate the formulation of policies for the sharing of spatial data for decision-making and preventive disaster management. The results indicate that the 39 institutions share spatial data, but this sharing is not always predetermined by formal agreements. Furthermore, there is a strong demand, by the institutions involved in the management of RTHM accidents, regarding legal mechanisms governing the sharing of data for the purpose of producing maps that help to describe actions of preparedness, prevention, management and immediate relief involving RTHM incidents. Finally, it was possible to propose a conceptual framework with data that is considered essential for creating an SDI for RTHM.     

Interactions of an urban heat island and sea-breeze circulations during winter over the metropolitan area of São Paulo,Brazil

The Town Energy Budget (TEB) model, a detailed urban parameterisation using a generalised canyon geometry, coupled with the Regional Atmospheric Modelling System (RAMS) is used to simulate the wintertime local circulation in the megacity environment of the metropolitan area of Sao Paulo (MASP) in Brazil. Model simulations are performed using actual topography and land-use fields. Comparison with a simple urban parameterisation based on the LEAF-2 scheme is also shown. Validation is based on comparison between model simulations and observations. Sensitivity tests with TEB reveal an important interaction between the sea breeze and the MASP heat island circulation. Even though topography is known to play an important role in the MASP region’s weather, in these tests the simulations were performed without topography in order to unambiguously identify the interaction between the two local circulations. The urban heat island (UHI) forms a strong convergence zone in the centre of the city and thereby accelerates the sea-breeze front toward the centre of the city. The presence of the urban region increases the sea-breeze front propagation mean speed by about 0.32 m s⁻¹ when compared with the situation of no city. After its arrival in the urban region, the sea-breeze front stalls over the centre of the city for about 2 h. Subsequently, the sea breeze progresses beyond the city when the heat island dissipates. Thereafter, the sea breeze propagates beyond the urban area at a decelerated rate compared to a simulation without an UHI.     

Hydrofluoric Acid‐Free Digestion of Geological Samples for the Quantification of Rare Earth Elements by Inductively Coupled Plasma‐Optical Emission Spectrometry

Rare earth elements (REEs) are very important to technological development as well as to geochemical and environmental studies. In this work, hydrofluoric acid (HF) was replaced by condensed phosphoric acid (CPA) in the digestion of geological samples, and the quantification of REEs was performed by inductively coupled plasma‐optical emission spectrometry (ICP‐OES). Six international reference materials (RMs), named DC86318, CGL 111, CGL 124, CGL 126, OKA‐2 and COQ‐1 and three Brazilian ore samples, named Araxá, Catalão and Pitinga were analysed. Only zircon and xenotime, which are potential REE‐bearing minerals, were not completely dissolved. Nevertheless, no REE associated with zircon was detected. The investigated digestion method presented many advantages: It was relatively fast (3 h), avoided fluoride precipitation, it was less hazardous because handling diluted H₃PO₄ is safer than HF, NH₄F or NH₄HF₂ aqueous solutions, it preserved the quartz fittings of the measurement equipment and the final solution contained lower levels of total dissolved solids than those produced by the fusion method.     

Assessing the control exerted by soil mineralogy in the fixation of potentially harmful elements in the urban soils of Lisbon,Portugal

The main purposes of this study are the textural, chemical and mineralogical characterization of the urban soils of Lisbon and the identification of probable relations between the several soil properties. The results are used to infer which soil properties control the superficial dispersion of potential harmful elements to human health. Soil sampling was carried out in 51 selected sites all through the city, under the criterion that such sites should be spaces usually frequented by children. The concentrations of 42 elements in the >2 mm soil size fraction were determined at a commercial laboratory in Canada (ActLabs, LTD), by ICP-MS/ICP-OES after an acid digestion with aqua regia. The soil mineralogy was determined by X-ray diffraction in the <2 and <62 μm size fractions. The results indicate that the urban soils have mainly a sandy texture and a main mineralogical assemblage of quartz, K-feldspar, plagioclase and calcite. In terms of clay minerals, smectite, illite and kaolinite are the main clays in the soil. Smectite and illite show a dichotomy in their distribution, with the smectites prevailing in the soils of the volcanic complex of Lisbon, which are classified as being residual, and illite prevailing in the remaining soils, which are considered mainly as man-made soils. Smectite seems to exert an important role in the fixation of Ni and Cr. The results of the geochemical study show that Ni and Cr have concentrations above the soil guideline value established to the UK and pose a probable risk to human health.     

Analyzing the spatial interactions between rainfall levels and flooding prediction in São Paulo

Rainfall is one of the primary triggers for many geological and hydrological natural disasters. While the geological events are related to mass movements in land collapse due to waterlogging, the hydrological ones are usually assigned to runoff or flooding. Studies in the literature propose predicting mass movement events as a function of accumulated rainfall levels recorded at distinct periods. According to these approaches, a two-dimensional rainfall levels feature space is segmented into the occurrence and non-occurrence decision regions by an empirical critical curve (CC). Although this scheme may easily be extended to other purposes and applications, studies in the literature need to discuss its use for flooding prediction. In light of this motivation, the present study is unfolded in (1) verifying that defining CCs in the rainfall levels feature space is a practical approach for flooding prediction and (2) analyzing how geospatial components interact with rainfall levels and flooding prediction. A database containing the rainfall levels recorded for flooding and non-flooding events in São Paulo city, Brazil, regarding the period 2015–2016, was considered in this study. The results indicate good accuracy for flooding prediction using only partial rain, which can be improved by adding physical characteristics of the flooding locations, demonstrating a direct correlation with spatial interactions, and rainfall levels.     

Vertical deformation partitioning across a collapsing large and hot orogen

Featuring 3 000-km-long large and hot orogen, the Mantiqueira Province provides a rare opportunity to study the process of gravitational collapse at mid to deep crustal levels. Distinct but contemporary (~500 Ma) post-collisional intrusions show structures and anisotropy of magnetic susceptibility (AMS) fabrics related to their emplacements, recording different flow patterns. In southern deep-seated intrusions, ellipsoidal-shaped roots with gabbroic-to-hybrid cores surrounded by granitic rocks show concentric patterns of AMS fabrics that cut across the NE-trending regional foliation. In contrast, northern intrusions, exposed as the upper sections of batholith-size bodies of coarse-grained granite emplaced at the shallow to mid-crust, show general NS-trending magnetic fabrics roughly parallel to strike of the orogen and the regional foliation of host rocks. These contrasting magnetic patterns from shallow to deeper crust suggest vertical magma migration from the overthickened orogenic core to be emplaced across its thinner stretched flanks during the gravitational collapse of the orogenic edifice.     

Paleoenvironmental dynamics in central-eastern Brazil during the last 23 000 years: tropical peatland record in the Cerrado biome

The Cerrado biome is the second largest in Brazil, but the evolution of the Cerrado during the late Quaternary is not yet fully known. This study identifies paleoenvironmental changes during the last 23 000 years, based on a tropical mountain peatland record, in the Serra do Espinhaço Meridional in central-eastern Brazil. A multi-proxy approach was used that involved palynological analysis, stable isotopes (δ¹³C, δ¹⁵N), geochemistry, radiocarbon dating and multivariate statistics derived from a peatland core from Rio Preto (Minas Gerais state). The study reveals a very humid and cold climate during the late Pleistocene, with an increase in temperature and decrease in humidity at the Pleistocene–Holocene transition. During this period there was strong instability in the landscape (episodes of erosion). At the beginning of the Holocene there was a reduction in humidity with greater landscape stability. The current sub-humid climatic conditions seem to have been established in the mid-/late Holocene, with periods of landscape instability. Our findings agree with other Cerrado records that contradict previously established hypotheses, such as the Amazonian Refuge and the Pleistocene Arc.