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.

Soil, street dust, and bulk deposition (dry and wet deposition) were collected in the Metropolitan Area of Buenos Aires (MABA), Argentina, to assess the polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) pollution and the potential risks to human health. Compared with other countries, the mean concentration of PAHs and PCBs in surface soils, street dust and bulk deposition of MABA were at a low or moderate level. Average PAHs and PCBs concentrations in bulk deposition (5.7 ± 5.1 and 0.41 ± 0.25 µg g, respectively) were five and ten times higher than those of soil (1.08 ± 0.98 and 0.02 ± 0.01 µg g) and street dust (1.2 ± 0.95 and 0.04 ± 0.03 µg g), respectively. Different compositional profiles, observed in the three matrices for both groups of contaminants, could be attributed to dissimilar source contribution, partition processes between gas and particulate phases, and transformation. The most contaminated bulk deposition presented higher values for cancer and non-cancer risks relative to soil and street dust. In all matrices, non-carcinogenic risks were below the safety threshold (HI < 1). Regarding carcinogenic risks, exposure to both bulk deposition and soil indicated a moderated potential for cancerous development (Incremental lifetime cancer risk ~ 3.0 × 10).

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A mi Director, el Dr. Juan Carlos Colombo, por abrirme las puertas del LAQAB, por la supervisión de mis actividades, la minuciosa revisión del manuscrito y el apoyo brindado durante todo mi trabajo de investigación.A mi Co-Directora, la Dra. Natalia Cappelletti, por su compromiso, orientación, revisión y apoyo constante durante el desarrollo de la tesis.A todos los integrantes del LAQAB que me han ayudado en diversas actividades de mi trabajo, la Lic. Carolina Migoya por su apoyo y asesoramiento en las practicas de laboratorio, Dr. Leandro Tatone por la supervisión en el procesamiento y análisis de metales, Dra. Malena Astoviza por su asistencia en la determinación de hidrocarburos aromáticos y demás integrantes del laboratorio que de una u otra manera pudieron colaborar en este trabajo: Dr.