Spatial-temporal variations of metals and arsenic in sediments from the Doce River after the Fundão Dam rupture and their bioaccumulation in Corbicula fluminea

The rupture of the Fundão dam in Brazil released tons of mining tailings into the Doce River Basin (DRB). This investigation aimed to determine the bioaccumulation of metals in soft tissues of the bivalve Corbicula fluminea exposed to sediments collected in the DRB in four periods (just after, 1, 3, and 3.5 years after the dam rupture). In the exposure bioassays, the concentrations of Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn in sediments and bivalve soft tissues were quantified. The concentration of some elements (As, Cd, Mn, and Al) in sediments exceeded the federal limits or regional backgrounds at some sampling sites, but their concentrations tended to decrease over time. However, higher concentrations of many elements were detected in the winter of 2019. Several elements were detected in C. fluminea soft tissues, but the bioaccumulation factors were generally low or not related to those elements associated with the ore tailings, evidencing that the bioavailability of metals to bivalves, in laboratory conditions, was limited. Integr Environ Assess Manag 2024;20:87-98. © 2023 SETAC.

The influence of Amazon River connectivity to littoral meanders on long-term carbon accumulation: A case study of Lake Yahuarcaca

The objective of this investigation is to evaluate the recent changes in the accumulation of organic matter and carbon on the Yahuarcaca lake system, by means of a multiproxy paleolimnological study. The methodology based on lithological descriptions of 210Pb/137Cs-dated cores allowed us to infer the centennial sedimentation processes and carbon accumulation rates. Sedimentary facies, grain size, magnetic susceptibility, loss on ignition, carbonate, chlorophyll derivatives, stable isotopes of δ13C/δ15N, and carbon accumulation rate were analyzed. LANDSAT and photographic record of satellite images were used to reconstruct the historical geomorphological evolution of the Lake. Sediment cores yielded basal ages of 1827 and 1828 Common Era, representing the formation of lakes as a consequence of the Amazon meandering process. Two main paleolimnological stages were identified, with a boundary transition set at 1980-1984 Common Era, attributed to the geomorphological closure and complete lake separation from the Amazon and the onset of full lentic conditions. This inference was mainly based on both sharp increases in the sedimentation rate from 0.2 to >1 cm yr-1 and carbon accumulation that increased seven-fold (from 2 to 14 g m-2 yr-1) from 1980 to 1984 Common Era. The flood-pulse and connection to the Amazon defined the magnitude of organic inputs, where areas more distant/isolated from the river showed higher accumulation of carbon from autochthonous production, with an average of 8.9 % and 1.10 g m-2 yr-1 (carbon accumulation rate). Those areas closer and connected to the river were strongly related to the interannual hydrological variability, with a lower mean carbon content (5.9 %) and 0.73 g m-2 yr-1 (carbon accumulation rate). We concluded that carbon burial was highest within the most distant spot from the Amazon River because of the weaker connection to the river itself and the more stable lentic conditions for net sedimentation.

Biogeochemical and oceanographic conditions provide insights about current status of an Antarctic fjord affected by relatively slow glacial retreat

Understand the origin, transport, and character of organic matter entering Antarctic fjords is essential as they are major components of the global carbon cycle and budget. Macromolecular pools of particulate organic matter, bulk organic geochemistry, major and trace elements in surface sediments from Collins Bay were analysed as source indicators. Oceanographic conditions, bathymetry (multibeam) and grain size were considered as environmental controlling factors. Sediment samples were taken with a van Veen grab, during the ANTAR XXV Peruvian expedition (February 2018), onboard the R/V "BAP Carrasco" from the Peruvian Navy. Biopolymeric composition revealed the predominance of fresh marine protein-rich organic matter in the seafloor of Collins Bay, denoting high quality food resource for marine benthic heterotrophs. Based on Igeo values (between 0 and 1) Collins Bay can be considered unpolluted with natural levels of As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn. Distribution of most of these elements with a gradient of decrease from the shallow inner fjord towards the outer deepest fjord, suggest their association with the deposition of detrital material and lithogenic particles supplied by Collins Glacier frontal ablation and runoff. This first comprehensive baseline information would assist in interpreting downcore sedimentary reconstructions and future climate-induce changes.

Benthic foraminifera as proxies for assessing the effects of a pier marina construction: A case study in the naturally stressed environment of the Saco da Ribeira (Flamengo Bay, SE Brazil)

Brazilian coastal areas have been exposed to various anthropic influences including physical alteration such as marina construction. To assess the impact of the pier marina construction in the Saco da Ribeira cove (Flamengo Bay, SE Brazil), sedimentological (grain size), geochemical (organic and trace elements) parameters and benthic foraminifera were analyzed on a 50-cm-long dated sediment core covering the last century. The multiproxy approach applied to a numerical hydrodynamic model shows that the circulation in the study area underwent an overall reduction (ca. 30 %) after the pier marina construction in the 1970s, promoting an increase of mud accumulation and higher concentrations of total organic carbon and trace elements (i.e., Enrichment Factor Cu from 0.80 to 1.4) as well as a shift in the benthic foraminiferal assemblages (i.e., foraminiferal density from 63 to 23.20 specimens per 10 cm3 and dominance from 0.13 to 0.73). On the basis of these integrated data, better environmental conditions occurred before the 1970s, then an overall increase in environmental stress took place after the pier's marina construction. Our results provide a baseline for future biomonitoring projects in a stressed region and exemplify the strong capability and reliability of benthic foraminifera as bioindicators of paleoenvironmental changes in coastal environments and for understanding how human pressure might induce such changes.

Polycyclic aromatic hydrocarbons in a Natural Heritage Estuary influenced by anthropogenic activities in the South Atlantic: Integrating multiple source apportionment approaches

Polycyclic aromatic hydrocarbons (PAHs) were analysed in the sediments of one of the most well-preserved estuaries in South Brazil, the Paranaguá Estuarine System (PES), using several source apportionment tools. The ∑PAH ranged from < DL to 125.6 ng g^-1 dw (dry weight) (average 29.9 ± 26.1 ng g^-1 dw), and the lowest levels detected were similar to those found in other protected areas of the world. In general, the PAH concentrations indicated excellent environmental quality for the entire estuary. Principal component analysis indicated that fine sediments and total organic carbon were the main factors controlling PAH concentrations in the PES. Multiple PAH sources were identified in the study area; biomass burning and fossil fuel combustion predominated but considerable amounts of petrogenic residues were also observed. We identified evidence of a contribution from an adjacent watershed resulting from the construction of interconnections between large rivers and from years of intense deforestation in the local Atlantic Forest.

Unusual natural polycyclic aromatic hydrocarbons in sediment cores of an Amazon estuary

Polycyclic aromatic hydrocarbons (PAHs) most likely derived from natural sources were observed in two sediment cores covering the last 100 years in an Amazon estuarine region. A considerable change in the PAHs main source was observed in the 1960s. Before the 1960s, the sources of PAHs seem to be related to biogenic and/or early-diagenetic processes. Concentrations of perylene were higher before the 1960s and suggest that its primary source to the sediments in the Amazon region is linked to a short-term diagenetic transformation of their biogenic precursors. The natural formation of alkylated PAHs in sediments was linked to the methylation of the parental aromatic hydrocarbons due to sediment maturation processes and the dehydrogenation of sterols in the sediments. The relatively rapid reaction occurring in recent sediments of the Amazon region suggests the importance of the microbial community in the transformation of biogenic precursors to alkylated-PAHs in the sediments.

The effect of agricultural intensification and water-locking on the world's largest coastal lagoonal system

The palaeolimnological conditions of Mirim Lagoon, a large coastal shallow lagoon under the influence of historical human impacts related to the development of the primary sector of the economy were reconstructed. The first significant human impact consisted of locking the estuarine system to induce the transition from brackish to freshwater conditions. During this transition, the sedimentation rate consistently increased from pre-disturbance values of 0.25 cm yr^-1 to >1 cm yr^-1. A concomitant increase in nitrogen and carbon values was recorded indicating a related eutrophication process. The highest nutrient levels were achieved during the 1990s after the incorporation of cutting-edge technologies for agricultural production such as high-yielding varieties of rice resistant to climate variability and pests, and the use of inorganic fertilisers, pesticides and water supply controlled by irrigation. After 2011, the soybean production boosted and the area cultivated with this oilseed equalled the area of rice paddies, i.e., 2 × 10⁵ ha. A sharp decrease in δ¹³C from -19 to -24‰ and in δ¹⁵N from 6 to 2‰ were observed in the sedimentary record, indicating a major shift in the composition of the organic matter after the agricultural intensification. Trace elements Cr, Cu, Ni and Zn showed a high positive correlation with Al and Fe, and enrichment factors near 1, indicating a natural and terrigenous source of these elements and also unpolluted conditions. However, the increase of As after 1990 and the positive correlation with Pb was associated with agricultural practices. All elemental ratios (K/Al, Ti/Al and V/Cr) showed constant pre-disturbance trends and a turning point ca. the 1990s. Microplastics were detected from the beginning of the 1990s and increased towards recent sediments, thus corroborating an anthropogenically impacted scenario. Therefore, the development of the primary sector of the economy exerted clear impacts on the environmental quality of the system.

Reconstruction of the palaeo-ecological quality status in an impacted estuary using benthic foraminifera: The Santos Estuary (São Paulo state, SE Brazil)

The Santos Estuary (SE Brazil) is a coastal ecosystem with a high ecological importance and has been strongly impacted by human activities over the last century. A multiproxy analysis of sediment core dated by ¹³⁷Cs, ²¹⁰Pb and ²²⁶Ra activities and based on sediment geochemistry and benthic foraminifera is here used to reconstruct the environmental changes and the variations of the Palaeo-Ecological Quality Status (Palaeo-EcoQS) during the last ~120 years. The Palaeo-EcoQS was reconstructed by applying the diversity index Exp(H'_bc) based on the benthic foraminiferal fauna. Specifically, the Ecological Quality Ratio (EQR) allowed to assess the Palaeo-EcoQS during the last ~120 years using local reference conditions. Based on our data, the pre-industrial period (~1883-1902) represents the reference conditions with "Good" Palaeo-EcoQS. The ~1902-1972 period coincides with the beginning of industrial operations and intensification of coastal urbanization leading to a deterioration of the environmental quality and Palaeo-EcoQS shifting to "Moderate" conditions. Dredging operations in 1972 led to increase the influences of adjacent sea that ultimately resulted in a "Good" Palaeo-EcoQS persisting up to the 1990s. Despite the preservation actions and recovery programs, the 1993-2012 period was characterized by an overall deterioration of the environmental conditions. Indeed, the reconstructed "Poor" to "Bad" Palaeo-EcoQS suggest the ineffectiveness of the remediation actions. This work confirmed that benthic foraminifera are reliable to evaluate EcoQS and Palaeo-EcoQS in estuarine ecosystems. Based on the present findings and previous studies showing the potential of fossil foraminifera to define in situ reference conditions, we recommend the inclusion of foraminifera in the list of biological quality elements within legislations concerning transitional and marine habitats.

Organic contaminants and trace metals in the western South Atlantic upper continental margin: Anthropogenic influence on mud depocenters

Trace metals, dichloro-diphenyl-trichloroethane (DDTs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) were quantified in surface sediments from mud depocenters located in the western South Atlantic upper continental margin. There was no anthropogenic trace metal pollution observed, and the higher As values were attributed to high CaCO3 content in the area. The results indicate PCB sources associated with long-range atmospheric transport in addition to past DDT use for agriculture and pest control. PAHs were mainly originated from biomass and fossil fuel combustion, and their distribution is in alignment with the riverine runoff influence in southern region, which is transported towards the northern regions by coastal currents. Higher concentrations of 2-3 ring PAHs and DDTs in shallow and northern stations indicate a coastal influence. This work presents baseline information on the extent of anthropogenic influence in mud depocenters located in the western South Atlantic upper continental margin, showing these locations as potential source to sink of anthropogenic contaminants.

Depositional input of hydrocarbons recorded in sedimentary cores from Deception and Penguin Islands (South Shetland Archipelago, Antarctica)

Polycyclic aromatic hydrocarbons (PAHs) and aliphatic hydrocarbons (AHs), including petroleum biomarkers, were studied in four sediment cores collected around Deception and Penguin Islands, Antarctica. Total PAHs in Deception Island (DCP) samples ranged from 2.0 to 26.8 ng g^-1, and in Penguin Island (PGI) varied between 13.2 and 60.3 ng g^-1. Multiple sources of PAHs were verified in DCP, with petrogenic-derived compounds being predominant over the last 10 years. In PGI, PAHs related to natural contributions from the erosion of coal deposits were reported. Total AHs in DCP ranged from 4.5 to 19 μg g^-1 and in PGI varied between 5.3 and 21.9 μg g^-1. In DCP, the n-alkanes distribution pattern showed the presence of petroleum residues in the top sections and both terpanes and hopanes were detected, related to the use of fossil fuels for power generation and in different types of vessels. In PGI, the main source of n-alkanes was marine inputs and only terpanes were detected. The slight increase in hydrocarbon levels observed from 1980 onward in DCP was assumed to be due to the development of tourism in the region and to the scientific station activities. In PGI, anthropogenic-related hydrocarbons were detected in the recent sections and were linked to the development of tourism near the island, scientific activities and the increase in vessel traffic. In general, the concentrations of hydrocarbons found around both islands were comparable to those found in uncontaminated Antarctic regions.

Tracking the historical sewage input in South American subtropical estuarine systems based on faecal sterols and bulk organic matter stable isotopes (δ13C and δ15N)

Faecal sterols and stable isotopes (δ¹³C and δ¹⁵N) from bulk organic matter (OM) were analysed in three sedimentary cores collected in two subtropical bays located in the South Atlantic to evaluate historical trends in the sewage input and to track possible changes in the bulk isotopic composition of OM in recent decades. The values of δ¹³C and δ¹⁵N ranged from -27.4 to -25.0‰ and from 0.5 to 3.9‰, respectively, without a clear trend in the variation over the whole period covered by sediment cores and with no conclusive interpretation of a specific range value typically related to the sewage input for these areas. The maximum coprostanol concentration was 0.19 μg g^-1 in the upper 4 cm of one core, which was not considered contaminated by evaluation of the sterols diagnostic ratios. Even at low levels, the coprostanol concentrations followed variations in urban and economical regional development. Baseline values for faecal sterols (in average between 0.03 and 0.05 μg g^-1), which may represent a previous non-impacted environment scenarios, were calculated for use in comparative perspectives for future evaluations of the sewage input and contamination.

Spatial variability in the concentrations of metals in beached microplastics

Heavy metals and microplastics have been considered as threats to the marine environment and the interactions between these two pollutants are poorly understood. This study investigates the interactions between metals adsorbed in pellets collected randomly from 19 beaches along the coast of São Paulo State in southeastern Brazil, comparing these levels with those in virgin pellets. The samples were analyzed for Al, Cr, Cu, Fe, Mn, Sn, Ti and Zn by inductively coupled plasma optical emission spectroscopy (ICP-OES). The polymers were solubilized via acid digestion. The highest levels occurred with Fe (227.78mgkg^-1 - Itaguaré) and Al (45.27mgkg^-1 - Guaraú) in the same areas, which are closer to the Port of Santos. The metal adsorption on pellets collected is greater than that on virgin pellets. In this context, pellets can be considered to be a carrier for the transport of metals in the environment, even in small quantities.

Depositional history of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) in an Amazon estuary during the last century

The sources and depositional history of OCPs (organochlorine pesticides), PCBs (polychlorinated biphenyls) and PAHs (polycyclic aromatic hydrocarbons) over the last 100years were determined in two sediment cores collected in the Amazon region. It was possible to distinguish two depositional periods along the cores. The first period occurred before extensive anthropogenic effects were registered in the sediments. During this time interval, the concentrations of all OCPs and PCBs were below the detection limits (DL), and the PAH concentrations were low and essentially constant (58.19-124.28ngg^-1). The second period starts in the mid-1960s and reflects the increased human influence in the area. The concentrations of OCPs, PCBs, and PAHs increased towards the top of the cores, varying between <DL to 72.67ngg^-1, <DL to 0.87ngg^-1 and 331 to 2341ngg^-1, respectively. In general, OCP results showed trends corresponding to the production, usage and prohibition periods of POPs in Brazil. Compounds related to wood treatment, such HCHs and chlordanes, were predominant among the OCPs, which may be associated with many sawmills located in this region. The increase in PAH concentration after the 1960s is mainly due to forest fires, caused by the implementation of large-scale cattle ranches, which burned forests to create pastures. The background PAH concentrations before the 1960s are probably related to natural diagenetic processes.

Unraveling the performance of the benthic index AMBI in a subtropical bay: The effects of data transformations and exclusion of low-reliability sites

We investigated the relationship between the AMBI index and different contamination proxies in an urbanized bay in South America (SE Brazil), and the effect of (a) abundance data transformation and (b) exclusion of low-reliability sites (high SD; low N) on the index' performance. Poor ecological quality and opportunistic species were related to an increase in contaminants concentrations and mud content. Good ecological status and sensitive species (EG I) were mainly related to increased hydrodynamics. Data transformation caused minimal changes to the overall relationships, but exclusion of low-reliability sites improved the relationship between ecological groups and contamination proxies. Our results show that AMBI is robust in detecting effects of different contaminants in the area and reinforce the importance of the index as a tool for coastal management, but local joint efforts are needed to improve and adjust local species classification in ecological groups to improve the index' performance.

Historical economic and environmental policies influencing trace metal inputs in Montevideo Bay, Río de la Plata

Montevideo Bay is located in the middle zone of the Rio de la Plata, and since the foundation of the city, several key economic and environmental policies affected the industry, and thus, metal inputs into this ecosystem. The aim of this study is to evaluate the sedimentary geochemical record of Montevideo Bay, in order to determine the historical inputs of anthropogenic metals to the system. In addition, environmental and economic policies of the country were taken into account to infer the relationship between them and the historic metal input. Concentrations of aluminum, chromium, copper, lead, scandium and zinc were analyzed and the EF and SPI indices were calculated. The analysis showed that since Montevideo foundation, metal concentrations increased in accordance with industry development, and the indices as well as the metal concentration represent a reliable footprint of the history of different economic and environmental policies influencing historical industrial activities.

Levels of metals, arsenic and phosphorus in sediments from two sectors of a Brazilian Marine Protected Area (Tupinambás Ecological Station)

The Tupinambás Ecological Station (TES) is a Marine Protected Area consisting of two sectors: the Archipelago of Alcatrazes and the Cabras and Palmas islets. This investigation aimed to provide a first diagnosis of the concentrations of metals (Al,Cr,Cu,Fe,Hg,Ni,Pb,Zn), As and P in sediments from the TES. 24 sediment samples were collected in both sectors using a Van Veen grab sampler. Sediment textures and levels of Organic Matter (OM) and CaCO3 were determined, as well as the concentrations of the above-mentioned elements after partial acid digestion. Sediments were predominantly sandy. Higher levels of CaCO3 occurred in the Alcatrazes sector, whereas the OM contents were higher in the islets sector. Metals concentrations were low and associated with fines, while P and As presented a different behavior. The observed concentrations to all studies elements in sediments from the TES were considered as background values.

Assessment of historical fecal contamination in Curitiba, Brazil, in the last 400 years using fecal sterols

A 400-year sedimentary record of the Barigui River was investigated using fecal biomarkers and nutrient distribution. The temporal variability in cholesterol, cholestanol, coprostanol, epicoprostanol, stigmastanol, stigmasterol, stigmastenol, sitosterol, and campesterol between 1600 and 2011 was assessed. Anthropogenic influences, such as deforestation and fecal contamination from humans and livestock, were observed from 1840. The sterol ratios exhibit evidence of hens, horses, cows, and an unknown herbivore, which may be a capybara (Hydrochoerus hydrochaeris), from 1820 and has been observed more markedly from 1970 onward. Human fecal contamination was detected from 1840 and was observed more markedly from 1930 due to population growth. Thus, the sanitation conditions and demographic growth of Curitiba seemed to be the main factors of human sewage pollution, as the coprostanol concentration over time was strongly correlated with the population growth (r=0.71, p<0.001) although diagenetic processes have also been observed.(1.)

Sedimentary record of PAHs in the Barigui River and its relation to the socioeconomic development of Curitiba, Brazil

Concentrations of polycyclic aromatic hydrocarbons (PAHs) were determined in a sediment core collected from the Barigui River, in Curitiba, South Brazil. The USEPA's 16 priority PAH concentrations ranged from 39ng g(-1) to 2350ng g(-1) of dry sediment over a period that corresponds temporally to between ca. 1855 and 2011. The concentrations and patterns of PAH distribution changed over this time period and may be associated with several episodes in the Curitiba's history. Two major PAHs concentration peaks occurred in approximately 1910 and 1970, which might reflect population increases due to immigration programs in the 1890s and the sudden economic development that occurred in Brazil from 1960 to 1980, "The Economic Miracle Period", respectively. Isomeric ratios revealed that the PAHs had predominantly pyrolytic sources. The population, number of highways and electric energy consumption of Curitiba, as indices of socioeconomic development, were positively correlated with PAH deposition in the sediment core from 1855 to 1970, indicating the influence of socioeconomic development on the environmental load of sedimentary PAHs.

Baseline concentrations of faecal sterols and assessment of sewage input into different inlets of Admiralty Bay, King George Island, Antarctica

The Antarctic region is one of the best preserved environments in the world. However, human activities such as the input of sewage result in the alteration of this pristine site. We report baseline values of faecal sterols in Admiralty Bay, Antarctica. Four sediment cores were collected during the 2006/2007 austral summer at the Ezcurra (THP and BAR), Mackelar (REF) and Martel (BTP) inlets. Concentrations of faecal sterols (coprostanol+epicoprostanol) were <0.16 μg g(-1), suggesting no sewage contamination and probable "biogenic" contributions for these compounds. Baseline values, calculated using the mean concentration of faecal sterols in core layers for THP, BAR, REF and BTP, were 0.04 ± 0.02, 0.03 ± 0.01, 0.07 ± 0.01 and 0.04 ± 0.02 μg g(-1), respectively. These results established as natural contributions of faecal sterols, suggesting that these markers can be useful indicators of human-derived faecal input and contributing to monitoring programs to prevent anthropogenic impacts.

Arsenic and other trace elements in two catfish species from Paranaguá Estuarine Complex, Paraná, Brazil

Concentrations of arsenic and four additional trace elements (Cu, Cr, Ni, and Zn) were determined by inductively coupled plasma-optical emission spectrometry in the muscular tissue of the yellow catfish (Cathorops spixii) and the urutu catfish (Genidens genidens) from Paranaguá Estuarine Complex, Brazil (PEC). The PEC can be characterized by an environment of high ecological and economic importance in which preserved areas of rainforest and mangroves coexist with urban activities as ports and industries. The average concentrations (in milligram per kilogram dry weight) of elements in the muscle tissue of C. spixii are as follows: Zn (31), As (17), Cu (1.17), Cr (0.62), and Ni (0.28). Similar concentrations could be found in G. genidens with exception of As: Zn (36), As (4.78), Cu (1.14), Cr (0.51), and Ni (0.14). Fish from the geographic northern rural region (Guaraqueçaba-Benito) display higher As concentrations in the muscle tissues than fish found in the south-western (urban) part of the PEC. An international comparison of muscle tissue concentrations of trace elements in fish was made. Except for Ni in C. spixii, a tendency of decrease in element concentration with increasing size (age) of the fish could be observed. According to the National Health Surveillance Agency of Brazil, levels of Cr and As exceeded the permissible limits for seafood. An estimation of the provisional tolerable weekly intake of As was calculated with 109 % for C. spixii and with 29 % for G. genidens.

Assessment of the health quality of Ria de Aveiro (Portugal): heavy metals and benthic foraminifera

This work analyses the distribution of heavy metals in the sediments of Ria de Aveiro (Portugal) assessed by total digestion and sequential chemical extraction of the sediments. The influence of environmental parameters on the living benthic foraminiferal assemblages was studied. The most polluted parts in the Ria de Aveiro are areas where the residence time is high and cohesive sediments are deposited. Organic matter, which is an excellent scavenger for a number of metals, is in general more abundant in the finer deposits of this lagoon, which act as sinks of anthropogenic pollutants. This condition is observed in Aveiro canals and Murtosa channel where sediments with the highest concentrations of Zn, Pb, Cu, and Cr are found. The sediments of Murtosa channel are also enriched in As, Co and Hg. In Aveiro canals the enrichment of heavy metals is mostly related to the past industrial production at their margins (ceramic and metallurgy), whereas in Murtosa channel with effluent discharges of the Chemical Complex of Estarreja. Foraminiferal density and diversity reach higher values near the lagoon mouth under higher marine influence and decline in general under very low-oxygen conditions. Some species seems to be indifferent to the increasing of TOC (e.g. Haynesina germanica and Ammonia tepida) and some have an opportunistic behaviour in areas with very depressed levels of oxygen (e.g. A. tepida and Quinqueloculina seminulum) whereas other species can better tolerate sulphide/reducing conditions (e.g. H. germanica, Bolivina ordinaria, Buliminella elegantissima, Bulimina elongata/gibba and Nonionella stella) a widespread condition in this lagoon. Foraminiferal density and some species are negatively correlated with concentrations of heavy metals. A most sensitive group of species to higher concentrations of heavy metals is identified (such as B. ordinaria, B. pseudoplicata and B. elongata/gibba) and another one of more tolerant species (such as H. germanica A. tepida and Q. seminulum). Foraminifera are more tolerate higher available concentrations (AC) of Zn in any phase than higher AC of Cu adsorbed do clay minerals (F1) and associated with Fe and Mn oxides (F2) and of Pb in F2; the phase F2, probably the most mobile phase, and even phase F1 seems to be more toxic than the increasing of metals in organic matter (F3).

Artificial and natural radioactivity in edible mushrooms from Sao Paulo, Brazil

Environmental biomonitoring has demonstrated that organisms such as crustaceans, fish and mushrooms are useful to evaluate and monitor both ecosystem contamination and quality. Particularly, some mushroom species have a high capacity to retain radionuclides and some toxic elements from the soil and the air. The potential of mushrooms to accumulate radionuclides in their fruit-bodies has been well documented. However, there are no studies that determine natural and artificial radionuclide composition in edible mushrooms, in Brazil. Artificial ((137)Cs) and natural radioactivity ((40)K, (22)(6)Ra, (2)(28)Ra) were determined in 17 mushroom samples from 3 commercialized edible mushroom species. The edible mushrooms collected were Agaricus sp., Pleurotus sp. and Lentinula sp. species. The activity measurements were carried out by gamma spectrometry. The levels of (137)Cs varied from 1.45 ± 0.04 to 10.6 ± 0.3 Bq kg(-1), (40)K levels varied from 461 ± 2 to 1535 ± 10 Bq kg(-1), (2)(26)Ra levels varied from 14 ± 3 to 66 ± 12 Bq kg(-1) and (228)Ra levels varied from 6.2 ± 0.2 to 54.2 ± 1.7 Bq kg(-1). (137)Cs levels in Brazilian mushrooms are in accordance with the radioactive fallout in the Southern Hemisphere. The artificial and natural activities determined in this study were found to be below the maximum permissible levels as established by national legislation. Thus, these mushroom species can be normally consumed by the population without any apparent risks to human health.

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.

Radiocarbon geochronology of the sediments of the São Paulo Bight (southern Brazilian upper margin)

The aim of this work was to generate an inventory of the data on radiocarbon datings obtained from sediments of the São Paulo Bight (southern Brazilian upper margin) and to analyze the data in terms of Late Quaternary sedimentary processes and sedimentation rates. A total of 238 radiocarbon datings from materials collected using differents ampling procedures was considered for this work. The sedimentation rates varied from less than 2 to 68 cm.kyr(-1). The highest sedimentation rate values were found in a low-energy (ría type) coastal system as well as in the upwelling zones of Santa Catarina and Cabo Frio. The lowest rates were found on the outer shelf and upper slopes. Our results confirm the strong dependency of the shelf currents, with an emphasis to the terrigenous input from the Río de La Plata outflow which is transported via the Brazilian Coastal Current, as well as of the coupled Brazil Current - Intermediate Western Boundary Current (BC-IWBC) dynamics on the sedimentary processes. At least three indicators of the paleo sea level were found at 12200 yr BP (conventional radiocarbon age) (103 meters below sea level - mbsl), 8300-8800 cal yr BP (13 mbsl) and 7700-8100 cal yr BP (6 mbsl).

Polycyclic aromatic hydrocarbons (PAHs) in a large South American industrial coastal area (Santos Estuary, Southeastern Brazil): sources and depositional history

Located in southeastern Brazil, the Santos Estuary has the most important industrial and urban population area of South America. Since the 1950's, increased urbanization and industrialization near the estuary margins has caused the degradation of mangroves and has increased the discharge of sewage and industrial effluents. The main objectives of this work were to determine the concentrations and sources of polycyclic aromatic hydrocarbons (PAHs) in sediment cores in order to investigate the input of these substances in the last 50 years. The PAHs analyses indicated multiple sources of these compounds (oil and pyrolitic origin), basically anthropogenic contributions from biomass, coal and fossil fuels combustion. The distribution of PAHs in the cores was associated with the formation and development of Cubatão industrial complex and the Santos harbour, waste disposal, world oil crisis and the pollution control program, which results in the decrease of organic pollutants input in this area.

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.

Depositional history of sedimentary linear alkylbenzenes (LABs) in a large South American industrial coastal area (Santos Estuary, Southeastern Brazil)

This paper reports the reconstruction of the contamination history of a large South American industrial coastal area (Santos Estuary, Brazil) using linear alkylbenzenes (LABs). Three sediment cores were dated by (137)Cs. Concentrations in surficial layers were comparable to the midrange concentrations reported for coastal sediments worldwide. LAB concentrations increased towards the surface, indicating increased waste discharges into the estuary in recent decades. The highest concentration values occurred in the early 1970s, a time of intense industrial activity and marked population growth. The decreased LAB concentration, in the late 1970s was assumed to be the result of the world oil crisis. Treatment of industrial effluents, which began in 1984, was represented by decreased LAB levels. Microbial degradation of LABs may be more intense in the industrial area sediments. The results show that industrial and domestic waste discharges are a historical problem in the area.

Historical record of polycyclic aromatic hydrocarbons (PAHs) and spheroidal carbonaceous particles (SCPs) in marine sediment cores from Admiralty Bay, King George Island, Antarctica

This paper describes the first results of polycyclic aromatic hydrocarbons (PAHs) and spheroidal carbonaceous particles (SCPs) in sediment cores of Admiralty Bay, Antarctica. These markers were used to assess the local input of anthropogenic materials (particulate and organic compounds) as a result of the influence of human occupation in a sub-Antarctic region and a possible long-range atmospheric transport of combustion products from sources in South America. The highest SCPs and PAHs concentrations were observed during the last 30 years, when three research stations were built in the area and industrial activities in South America increased. The concentrations of SCPs and PAHs were much lower than those of other regions in the northern hemisphere and other reported data for the southern hemisphere. The PAH isomer ratios showed that the major sources of PAHs are fossil fuels/petroleum, biomass combustion and sewage contribution generally close to the Brazilian scientific station.

Sedimentary changes on the Southeastern Brazilian upper slope during the last 35,000 years

A first evaluation of the sedimentary changes, including accumulation of inorganic and organic carbon on the upper slope off Southeastern Brazil under different climatic conditions, based on the analysis of a sedimentary core, is here presented. Results indicate that sedimentation rate as well sedimentary characteristics, including the nature of the organic carbon deposited during the LGM (Last Glacial Maximum), were different from the present deposition, indicating higher primary productivity during the LGM, to be accounted for by the higher values of marine organic carbon. Nevertheless, the higher values of Accumulation Rate of calcium carbonate and organic carbon can be credited to the higher values of the sedimentation rates. Conditions prevailing during Isotope Stage 3 may be considered intermediate as between the LGM and the present day. The conditions for a higher primary productivity associated with the deposition of finer terrigenous sediments may be explained as a response to the off shoreward displacement of the main flow of the Brazil Current.

Distribution of 137Cs, 238Pu and 239+240 Pu in sediments of the southeastern Brazilian shelf-SW Atlantic margin

In this work levels of 137Cs, 238Pu and 239+240 Pu as well as activity ratios of anthrophogenic radionuclides in sediment samples from the southeastern Brazilian shelf are presented. Instrumental gamma spectrometry was used to determine 137Cs and alpha spectrometry to determine 238Pu and 239+240 Pu after a radiochemical procedure. The levels ranged from 0.30 to 1.79 Bq kg(-1) for 137Cs, from 15 to 150 mBq kg(-1) for 238Pu and, from 18 to 117 mBq kg(-1) for 239+240 Pu. There was a bathymetric differentiation in the radionuclides distribution. 137Cs values were generally higher in the samples collected at water depths of less than 100 m. On the other hand, plutonium isotopes exhibit higher values at greater depths. The mean ratio of 239+240 Pu/137Cs obtained was 0.112+/-0.072 which is in agreement with the value reported for the Atlantic from atmospheric fallout of nuclear explosions in the past. The 238Pu/230+240 Pu ratios varied widely (from 0.339 to 2.088) and showed the influence of the SNAP-9A accident in the 238Pu levels for this area. The main goal of this work was to present unpublished anthropogenic radionuclide levels and activity ratios related to the contamination of the southeastern Brazilian shelf.