PCB and PBDE levels in a highly threatened dolphin species from the Southeastern Brazilian coast

In the Northern coast of Rio de Janeiro State is located the major urban centers of the oil and gas industry of Brazil. The intense urbanization in recent decades caused an increase in human use of the coastal areas, which is constantly impacted by agricultural, industrial and wastewater discharges. Franciscana dolphin (Pontoporia blainvillei) is a small cetacean that inhabits coastal regions down to a 30 m depth. This species is considered the most threatened cetacean in the Western South Atlantic Ocean. This study investigated the levels of 52 PCB congeners and 9 PBDE congeners in liver of nine individuals found stranded or accidentally caught between 2011 and 2012 in the Northern coast of Rio de Janeiro. PCB mean levels ranged from 208 to 5543 ng g−1 lw and PBDEs mean concentrations varied between 13.84 and 36.94 ng g−1 lw. Contamination patterns suggest the previous use of Aroclor 1254, 1260 and penta-BDE mixtures in Brazil. While still few studies have assessed the organic contamination in cetaceans from the Southern Hemisphere, including Brazil, the levels found in this study could represent a health risk to these endangered species. •PCBs and PBDEs were measured in liver samples from Franciscana dolphins.•BDE 47, 99 and 100 were found in all individuals samples.•PCB-153, 138 and 180 were the major PCB congeners detected.•Results suggest the existence of PCBs and PBDEs contamination sources in Brazil.•PCBs and PDBEs levels could represent a risk to these endangered dolphin species. PCB and PBDE concentrations found in Franciscana dolphins suggest the presence of contamination sources in Southeastern Brazil and could represent a high health risk to these endangered species.