Perfiles verticales de metales en sedimentos del Río Uruguay, Argentina

Fil: Tatone, Leandro Martín. Laboratorio de Química Ambiental y Biogeoquímica. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Bilos, Claudio. Laboratorio de Química Ambiental y Biogeoquímica (LAQAB). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Skorupka, Carlos Norberto. Laboratorio de Química Ambiental y Biogeoquímica (LAQAB). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Colombo, Juan Carlos. Laboratorio de Química Ambiental y Biogeoquímica (LAQAB). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin

Dinámica de metales pesados en la laguna Inés (Bahía de Ñandubaysal, Río Uruguay)

Fil: Bilos, Claudio. Laboratorio de Química Ambiental y Biogeoquímica (LAQAB). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Tatone, Leandro Martín. Laboratorio de Química Ambiental y Biogeoquímica (LAQAB). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Skorupka, Carlos Norberto. Laboratorio de Química Ambiental y Biogeoquímica (LAQAB). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Colombo, Juan Carlos. Laboratorio de Química Ambiental y Biogeoquímica (LAQAB). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin

Airborne PCB patterns and urban scale in the Southern Río de la Plata Basin, Argentina

Atmospheric Polychlorinated Biphenyls (PCBs:Σ42 congeners) collected by polyurethane passive samplers (PAS-PUFs) in 29 stations from July 2010 to February 2014 (n = 141) in the most productive and populated Southern Rio de la Plata area in Argentina were evaluated to assess concentration gradients, potential sources and compositional profiles related to different land use and urbanization. On a global scale, total airborne PCBs concentrations are low/very low (below detection limit to 937 pg m−3) and show a significant potential correlation with urban scale increasing 2.5 times each 10 times increase of population reflecting the primary role of urbanization controlling PCB emissions. Compositional patterns evaluated by principal component analysis (PCA) of individual congeners indicated that highly populated atmospheres are enriched in lighter, more volatile tri, tetra and penta chlorine congeners of lighter Aroclor mixtures (from 1242 to 1254) suggesting actual emission of fresh PCBs signatures from sealants, combustion and/or electrical equipment. Sub urban and rural sites show a gradual transition to heavier Aroclor mixtures (from 1254 to 1260) with predominance of more persistent hexa and hepta PCBs indicating an aged background signal resulting from long range transport and/or reemission from historic reservoirs such as soils.Facultad de Ciencias Naturales y Muse

Airborne PAHs and PCBs along a coastal, urban-industrial gradient in Rio de la Plata Estuary, Argentina

Atmospheric transport is the principal route of transference of Semivolatile Organic Compounds (SVOCs) from local to global distances. Airborne SVOCs such as Polycyclic aromatic hydrocarbons (PAHs) and Polychlorinated Biphenyls (PCBs) are included in the POP protocol under the Convention on Long-Range Transboundary Air Pollution (LRTAP) and the Stockholm Convention due to their toxicity and environmental persistence. Owing to their practicality (autonomous, easy handled and affordable), in the last decades, polyurethane foam passive air samplers (PUF-PAS) have been widely used to evaluate spatial and temporal patterns of SVOCs allowing a higher temporal resolution than active air samplers. La Plata city, capital of Buenos Aires state, is located 15 km away from the Rio de la Plata Estuary coast, in a highly industrialized (major oil refinery of the country and associated industries [4], an important shipyard and container port) and densely populated region of the country (about 1,000,000 inhabitants). In this study, we report the patterns of airborne PAHs and PCBs along a transitional gradient from the coast to urban-suburban area of La Plata City in order to evaluate their sources, composition and spatial variability.Facultad de Ciencias Naturales y Muse

Bioaccumulation of Polychlorinated Biphenyls and Chlorinated Pesticides by the Asiatic Clam <i>Corbicula fluminea</i>; Its Use as Sentinel Organism in the Rio de la Plata Estuary, Argentina

Individual PCBs and chlorinated pesticides (CHLPs) were determined in water, suspended particles (SPM), sediments, and Asiatic clams to study their bioaccumulation kinetics and evaluate the usefulness of the clams as sentinel organisms. Bioaccumulation depended on the routes of uptake and bioavailability determined by compound hydrophobicity. CHLPs were mainly present in the dissolved phase, showed a positive correlation between the bivalve-water BAFs and Kow's and reached steady-state levels before 70 days in a caging experience. These facts reflect an efficient water-gill partitioning process. In contrast, PCBs were only detected in the SPM, showed essentiaIIy Kow, independent bivaIve-sediment and bivalve-SPM BAFs with the lowest values for superhydrophobic heptachlorobiphenyls 174,180, and 170, and did not reach steady-state levels during a 140-day exposure period. This suggests that the uptake was hindered by their stronger affinity for SPM and the interference of steric factors during intestine absorption. Corbicula fluminea are reliable sentinel organisms and showed clear geographical trends along 150 km of the Rlo de La Plata coast: a progressive decrease of PCB levels and more degraded patterns dominated by recalcitrant congeners, i.e., 153, were observed with increasing distance from the major La PIata-Buenos Aires urban center. A size-related trend overlapped with this spatial gradient: older clams usually showed higher levels and a more degraded PCB signature. CHLPs showed less clear geographical trends due to the presence of multiple sources. CHLP patterns showed a strong dominance of chlordan e - re la ted com po u n ds, pa rti c u I a rly transchlordane which was 2-5 times more abundant than the cis isomer. On a temporal scale, from 1986 to 1993, Asiatic clams presented sustained PCB levels but showed a significant decrease of chlordane and DDT, which suggests reduced inputs in recent years.Facultad de Ciencias Naturales y Muse

Mateship and Money-Making: Shearing in Twentieth Century Australia

After the turmoil of the 1890s shearing contractors eliminated some of the frustration from shearers recruitment. At the same time closer settlement concentrated more sheep in small flocks in farming regions, replacing the huge leasehold pastoral empires which were at the cutting edge of wool expansion in the nineteenth century. Meanwhile the AWU succeeded in getting an award for the pastoral industry under the new arbitration legislation in 1907. Cultural and administrative influences, therefore, eased some of the bitter enmity which had made the annual shearing so unstable. Not all was plain sailing. A pattern of militancy re-emerged during World War I. Shearing shed unrest persisted throughout the interwar period and during World War II. In the 1930s a rival union with communist connections, the PWIU, was a major disruptive influence. Militancy was a factor in a major shearing strike in 1956, when the boom conditions of the early-1950s were beginning to fade. The economic system did not have satisfactory mechanisms to cope. Unionised shearers continued to be locked in a psyche of confrontation as wool profits eroded further in the 1970s. This ultimately led to the wide comb dispute, which occurred as wider pressures changed an economic order which had not been seriously challenged since Federation, and which the AWU had been instrumental in shaping. Shearing was always identified with bushworker ‘mateship’, but its larrikinism and irreverence to authority also fostered individualism, and an aggressive ‘moneymaking’ competitive culture. Early in the century, when old blade shearers resented the aggressive pursuit of tallies by fast men engaged by shearing contractors, tensions boiled over. While militants in the 1930s steered money-makers into collectivist versions of mateship, in the farming regions the culture of self-improvement drew others towards the shearing competitions taking root around agricultural show days. Others formed their own contracting firms and had no interest in confrontation with graziers. Late in the century New Zealanders arrived with combs an inch wider than those that had been standard for 70 years. It was the catalyst for the assertion of meritocracy over democracy, which had ruled since Federation

Concentración de pesticidas organoclorados en aire del sur de la cuenca del Plata: un año de muestreo

Polyurethane foam passive air samplers (n=20) were deployed across the Southern del Plata basin to assess concentrations and distributions of Organochlorine Pesticides (OCPs) for ≈ 3-4 months periods all over a year. Annual average concentration of OCPs ranged from 326 to 9000 pg/m3 with predominance of endosulfans (Endo). Annual averages of Endo (230-8936 pg/m3) are higher than reported values for other countries from this region (Brazil, Bolivia, Chile y Colombia: 114-898 pg/m3). Maximum values correspond to the warm period in areas of intense soybean culture: North of BsAs and South of E. Ríos and Santa Fe (3072-21521 pg/m3).\nConcentrations of DDTs (12-235 pg/m3) are an order of magnitude lower than the sites where it is used against malaria at present (India: 5356pg/m3; South of Mexico: 2360 pg/m3) but DDT/DDE ratio (1.1-6.8) >1 suggests a relatively fresh contribution, possibly due to the use of dicofol that presents this compound impurity.\nThe HCHs showed high concentrations in Zárate (801-8348 pg/m3) where they predominanted (66% of the total) with an α/γHCHs ratio ≈7, similar to the technical mixture suggesting a fresh contribution.\nIn the metropolitan area chlordanes prevailed (83-691 pg/m3) representing 5-45% of the total, especially in Buenos Aires City, where the cis/trans-chlordane relationship >> 1.6 indicates a fresh contribution It was concluded that the OCPs have different spatial distribution: higher concentrations in agriculrure areas; diversity in composition of pesticides and higher values of clordanes in urban areas. Concentrations and relationship values suggest non-legal inputs or long range transport.Con el objeto de estudiar la concentración y distribución de plaguicidas organoclorados (POCLs) en aire del sur de la cuenca del Plata se instalaron muestreadores pasivos de espuma de poliuretano (n=20) recolectados cada 3-4 meses durante un año.\nLa concentración media anual de POCLs osciló entre 326 y 9000 pg/m3 con predominancia de endosulfanos (Endo) (40-98% del total). Los promedios anuales de Endo (230-8936 pg/m3) son superiors a los reportados para otros paises de la región (Brasil, Bolivia, Chile y Colombia: 114-898 pg/m3. Los valores máximos alcanzados corresponden al período cálido, en zonas de mayor actividad sojera: Norte de Bs As y Sur de E.Ríos y Santa Fe (3072-21521 pg/m3). Las concentraciones de DDTs (12-235 pg/m3) resultan un orden de magnitud inferiores a las de sitios en los que se utiliza para combatir la malaria (India: 5356 pg/m3; sur de México: 2360 pg/m3) pero la relación DDT/DDE (1.1-6.8) > 1 encontrada sugiere un aporte relativamente fresco, posiblemente debido al uso de Dicofol que presenta residuos de este compuesto.\nLos HCHs presentaron una alta concentración en Zárate (801-8348 pg/m3) donde resultaron predominantes (66% del total) con una relación α/γHCHs ≈7, similar a la de la mezcla técnica sugiriendo un aporte fresco.\nEn la zona metropolitana se destacaron los clordanos (83-691 pg/m3) que representan 5- 45% del total, especialmente en la Capital Federal, donde la relación trans/cisclordano>> 1,6 indica un aporte fresco.\nSe concluye que los POCLs presentan diferencias en su distribución espacial; alta concentración de endosulfanos en zona agrícola; heterogeneidad de pesticidas y mayor concentración de clordanos en zonas urbanas. Los valores de las concentraciones y de relaciones entre compuestos sugieren aportes frescos clandestinos, o transporte a gran escala

Long-Term (1970-2017) Temporal Trends of Polychlorinated Biphenyls in Fish, Settling Material, and Sediments from Populated and Remote Sites in Río de la Plata Estuary, Argentina

Temporal trends of polychlorinated biphenyls (PCBs) were studied for detritivorous fish (1996-2017) and settling material (2002-2017) from polluted Buenos Aires coast and for a dated sediment core (1970-2013) from the outer Río de la Plata estuary. In spite of contrasting concentrations [5.3 ± 6.3 μg·g -1 dry weight (dw) for fish, 48 ± 26 ng·g -1 dw for settling material, and 1.5 ± 0.7 ng·g -1 dw for core], all three revealed exponentially decreasing trends over time (97%, 83%, and 83%, respectively). Time trends showed peak maxima coincident with Argentina's period of maximum PCB usage in 1973-1980 (80 cm depth in the core) and pulse discharges related to PCB banning in 2001-2002 (fish) with a lighter signature enriched in less persistent tri- and tetrachlorobiphenyls. The log-linear PCB time trends compare well with the predicted decrease for a high emission scenario from global emission data; the best fit was observed for the less impacted sediment core (-2%·year -1 versus -3%·year -1 for emission scenario). Steeper slopes are observed for the more polluted settling material (-5%·year -1 ) and especially for fish, in which the background decline trend tripled after the 2001 PCB pulse (from -7%·year -1 to -21%·year -1 ). These PCB time trends in related environmental compartments from contrasted sites provide rare evidence for evaluating the effectiveness of control measures in southern South America.Fil: Colombo, Juan Carlos. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Química Ambiental y Biogeoquímica; ArgentinaFil: Speranza, Eric Demian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Química Ambiental y Biogeoquímica; ArgentinaFil: Astoviza, Malena. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Química Ambiental y Biogeoquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Migoya, Maria Carolina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Química Ambiental y Biogeoquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Skorupka, Carlos Norberto. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Química Ambiental y Biogeoquímica; ArgentinaFil: Morrone, Manuel. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Química Ambiental y Biogeoquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Heguilor, Santiago. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Química Ambiental y Biogeoquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Tatone, Leandro Martín. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Química Ambiental y Biogeoquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Bilos, Claudio. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Química Ambiental y Biogeoquímica; Argentin

Variabilité saisonnière et interannuelle de la qualité de l’eau du fleuve Uruguay, en Argentine

Water quality of the Uruguay River was evaluated with multi-parametric (temperature, turbidity, conductivity, pH, dissolved oxygen) and sediment trap data (particle flux, total organic carbon and nitrogen contents) and correlated to precipitation, river discharge and El Niño Southern Oscillation (ENSO) indices for the period 2006–2011. Hydro-meteorological parameters averaged 24–85% variability with coincident precipitation (200–400 mm month-1), discharge (7000–28 000 m3 s-1) and turbidity peaks (50–80 NTU) in the austral spring, and absolute maxima during the El Niño 2009 episode. Spectral analysis of discharge and sea-surface temperature anomaly (SSTA) showed consistent variance maxima at approx. 3 and 1.5 years. Deseasonalized discharge was significantly correlated to SSTA. During river floods, pH decreased (from 7.5 to 6.6) and particle dynamics peaked (turbidity: 15–80 NTU; vertical fluxes: 20–200 g m-2 d-1; total solid load: -1),whereas TOC remained stable (3.2 ± 0.8%) and C/N ratios increased (10–12) due to the higher contribution of terrestrial detritus.La qualité de l’eau du fleuve Uruguay a été évaluée avec des données multi-variables (température, turbidité, conductivité, pH, oxygène dissous) et des données de pièges à sédiments (flux de particules, teneurs en carbone et azote organiques), corrélées aux précipitations, aux débits et aux indices ENSO pour la période 2006–2011. Les variables hydrométéorologiques ont montré des moyennes de variabilité de 24 à 85%, analogues pour les précipitations (200–400 mm mois-1), les débits (7000–28 000 m3 s-1) et les pics de turbidité (50-80 NTU) au cours du printemps austral, et des maximums absolus pendant l’épisode El Niño de 2009. L’analyse spectrale du débit et de l’anomalie de température de surface de la mer (ATSM) a montré des maximums de variance cohérents pour des durées de 3 et 1,5 années environ. Le débit désaisonnalisé était significativement corrélé à l’ATSM. Pendant les inondations, le pH a diminué (de 7,5 à 6,6) et la dynamique des particules a connu un pic (turbidité : 15–80 NTU; flux verticaux : 20–200 g m-2 jour-1 ; charge solide totale : -1), alors que le carbone organique total est resté stable (3,2 ± 0,8%) et que les rapports C/N ont augmenté (10–12) en raison de la contribution plus élevée de détritus terrestres.Facultad de Ciencias Naturales y Muse