Andreza Portella Ribeiro

Multi-molecular markers and metals as tracers of organic matter inputs and contamination status from an Environmental Protection Area in the SW Atlantic (Laranjeiras Bay, Brazil).

The sources and concentrations of aliphatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs), faecal and biogenic sterols, and trace metals at 10 sampling sites located in Laranjeiras Bay, a large Environmental Protection Area in the southern Atlantic region of Brazil, were determined to assess the sources of organic matter and the contamination status of estuarine sediments. Organic compounds were determined by GC-FID and GC-MS, and ICP-OES was used to evaluate trace metals. The total AHs concentration ranged from 0.28 to 8.19 μg g(-1), and n-C(29) and n-C(31) alkanes were predominant, indicating significant inputs from higher terrestrial plants. Unresolved complex mixtures (UCM) were not detected at any site, suggesting that the study area was not significantly contaminated by fossil fuels. The total PAH concentration varied from 3.85 to 89.2 ng g(-1). The ratio between selected PAH isomers showed that combustion of biomass, coal, and petroleum is the main source of PAHs in the study area. The concentrations of the faecal sterols coprostanol and epicoprostanol were below the detection limits, suggesting that sewage was not a significant contributor to sedimentary organic matter. The concentrations of the trace metals (As, Cr, Cu, Ni, Pb and Zn) were low, except near sites located at the mouths of rivers that discharge into the study area and near urbanised regions (Paranaguá city and the adjoining harbour). In general, the concentrations of PAHs were below the threshold effect concentrations (TEL) levels. Although the As, Cr and Ni concentrations were above the TEL levels, the study area can be considered as preserved from human activities.

Arsenic and trace metal contents in sediment profiles from the Admiralty Bay, King George Island, Antarctica

Admiralty Bay (Antarctica) hosts three scientific stations (Ferraz, Arctowski and Macchu Picchu), which require the use of fossil fuel as an energy source. Fossil fuels are also considered the main source of pollution in the area, representing important inputs of major pollutants (organic compounds) and trace metals and metalloids of environmental interest. Accordingly, this work presents the results of As, Cd, Cr, Cu, Ni, Pb and Zn in sediment profiles from Admiralty Bay. The sediment results from Ferraz station were slightly higher than the other sampling sites. The highest contents were observed for Cu and Zn (from 44 to 89 mg kg(-1)). Otherwise, by using enrichment factors and geochronology analysis, the most relevant enrichment was observed for As in the samples collected close to the Ferraz station, indicating that increasing As content may be associated with the activities associated with this site.

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.

Bioaccumulation of potentially toxic trace elements in benthic organisms of Admiralty Bay (King George Island, Antarctica)

Data about the concentration, accumulation and transfer of potentially toxic elements in Antarctic marine food webs are essential for understanding the impacts of these elements, and for monitoring the pollution contribution of scientific stations, mainly in Admiralty Bay due to the 2012 fire in the Brazilian scientific station. Accordingly, the concentration of As, Cd, Cu, Ni, Pb and Zn was measured in eight benthic species collected in the 2005/2006 austral summer and the relationship between concentration and trophic position (indicated by δ(15)N values) was tested. A wide variation in metal content was observed depending on the species and the element. In the studied trophic positions, it was observed bioaccumulation for As, Cd and Pb, which are toxic elements with no biological function. In addition, Cd showed a positive relationship between concentration and trophic level suggesting the possible biomagnification of this element.

137Cs in marine sediments of Admiralty Bay, King George Island, Antarctica

The radionuclide cesium-137 ((137)Cs) is produced exclusively by anthropogenic processes and primarily by nuclear explosions. This study determined the reference inventory that is (137)Cs associated with the elements original input, and utilized the levels of activity of this radionuclide previously measured in five sediment profiles collected from Admiralty Bay, Antarctica, to investigate the mobility of this element in the environment. (137)Cs has a half-life of 30 years. Because of this, it is environmentally persistent and has been shown to accumulate in marine organisms. The mean reference inventory of this radionuclide in Admiralty Bay sediments, determined using high resolution gamma ray spectrometry, was 20.23±8.94 Bq m(-2), and within the ambient (137)Cs activity range. A model of (137)Cs diffusion-convection was applied to data collected from 1cm intervals in sediment cores with the aim of providing insights with respect to this elements behavior in sediments. Model results showed a significant correlation between measured and modeled values using the concentrations of (137)Cs, and estimated input into the system from the global fallout of past nuclear tests and expected values based on local sedimentation rates. Results highlight the importance of accounting for the vertical diffusion of (137)Cs in marine sediments when used as a tracer for environmental processes and for assessing potential bioavailability.

Reconstruction of historical trends in potentially toxic elements from sediment cores collected in Bertioga channel, southeastern Brazil

Este estudo apresenta uma avaliacao da deposicao de elementos potencialmente toxicos no Canal de Bertioga (costa sudeste brasileira) ao longo de 150 anos, periodo principal de atividade antropogenica na area. O trabalho analisou cinco testemunhos sedimentares por meio de ICP-OES para determinar os niveis de metais (Cd, Cr, Cu, Ni, Pb e Zn) e As. O indice de carga de poluicao (PLI) e o fator de enriquecimento (EF) foram calculados para identificar a toxicidade relativa dos elementos dos sedimentos e a contribuicao antropogenica dos elementos investigados. Os indices indicaram a ausencia de contaminacao por metais pesados, mas houve uma entrada mais elevada de As nos testemunhos B2 e B5, amostrados em area com maiores taxas de sedimentacao. Atraves de analise estatistica de decomposicao de series temporais, verificou-se que o fluxo de metais para a area segue os ciclos de estacoes chuvosa (verao austral) e seca (inverno austral). Como conclusao pode ser verificado que o enriquecimento observado corresponde ao final do seculo XIX, quando o Porto de Santos foi inaugurado, e a decada de 1970, quando as atividades do porto foram expandidas. Ainda, a analise dos indices e da decomposicao temporal indica que a entrada de As no Canal de Bertioga da-se por processos naturais de intemperismo e sedimentacao.

Metals and semi-metals in street soils of São Paulo city, Brazil

São Paulo is the largest city in Brazil and South America with about 20 million inhabitants in the metropolitan area, more than nine million motor vehicles and intense industrial activity, which are responsible for increasing pollution in the region. Nevertheless, little is known concerning metal and semi-metal content in the soils of this metropolitan region. This type of information could be extremely useful as a fingerprint of environmental pollution. The present study determined the elements As, Ba, Co, Cr, Sb, and Zn concentrations in soils adjacent to avenues of highly dense traffic in São Paulo city to assess their levels and possible sources. The analytical technique employed was Instrumental neutron activation analysis. The results showed, except for Co, concentration levels higher than the reference values for soils of São Paulo, according to the Environmental Protection Agency of the State of São Paulo guidelines. When compared to similar studies in other cities around the world, São Paulo soils presented higher levels, probably due to its high density traffic and industrial activity. The concentrations obtained for As and Cr indicate anthropogenic origin. The high levels of the traffic-related elements Ba, Sb, and Zn in soils nearby high density traffic avenues indicate they may originate from vehicular exhausts.

Elemental composition evaluation in lichens collected in the industrial city of São Mateus Sul, Paraná, Brazil

In this study, Canoparmelia texana lichenized fungi species was used as a passive biomonitor of the atmospheric pollution from the industrial city of São Mateus do Sul, PR, Brazil. Lichen samples collected from tree barks were cleaned, freeze-dried and analyzed by neutron activation analysis. Comparisons were made between the element concentrations obtained in lichens from this city and that from a clean area of Atlantic Forest in Intervales Park, SP. The high concentrations of elements As, Ca, Co, Cr, Fe, Hf, Sb, and Th found in lichens could be attributed to the emissions from a ceramic and an oil shale plants.

Tillandsia usneoides: a successful alternative for biomonitoring changes in air quality due to a new highway in Sao 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.

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.