High spatial variability in polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides, such as DDTs, and polybrominated diphenylethers was observed in plastic pellets collected randomly from 41 beaches (15 cities) in 2010 from the coast of state of São Paulo, southeastern Brazil. The highest concentrations ranged, in ng g(-1), from 192 to 13,708, 3.41 to 7554 and <0.11 to 840 for PAHs, PCBs and DDTs, respectively. Similar distribution pattern was presented, with lower concentrations on the relatively less urbanized and industrialized southern coast, and the highest values in the central portion of the coastline, which is affected by both waste disposal and large port and industrial complex. Additional samples were collected in this central area and PCB concentrations, in ngg(-)(1), were much higher in 2012 (1569 to 10,504) than in 2009/2010 (173 to 309) and 2014 (411), which is likely related to leakages of the PCB commercial mixture.

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We report the distribution of selected lipid biomarkers specifically sterols and aliphatic hydrocarbons in sediment cores from Cabo Frio, SW Atlantic continental shelf, Brazil, corresponding approximately to the last 700 years. In the Cabo Frio region, a costal upwelling occurs as a quasi-seasonal phenomenon characterized by nutrient-rich bottom waters that intrude on the continental shelf and promote relatively high biological productivity compared to other Brazilian continental shelf areas. The results for sterols indicate the predominance of organic matter (OM) inputs related to marine organisms, mainly plankton, in all of the cores along the time scale studied. Principal component analyses show three different groups of variables, which may be associated with (i) the more effective intrusion of the nutrient-rich South Atlantic Central Water, resulting in the increase of marine lipid biomarkers such as sterols and short-chain n-alkanes; (ii) the influence of the Coastal Water with higher surface water temperature and subsequently lower primary productivity; and (iii) OM characterized by high total organic carbon and long-chain n-alkanes related to an allochthonous source. Relatively high concentrations of sterols and n-alkanes between 1450 and 1700 AD, chronologically associated with the Little Ice Age, suggest a period associated with changes in the local input of specific sources of these compounds. The concentrations of lipid biomarkers vary over core depth, but this does not suggest a notably high or low intensity of upwelling processes. It is possible that the climatic and sea surface temperature changes reported in previous studies did not affect the input of the sedimentary lipid biomarkers analyzed here.

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