High accumulation of PCDD, PCDF, and PCB congeners in marine mammals from Brazil: A serious PCB problem

Abstract

• Dioxin-like PCBs accounted for over 83% of the total TEQ for all cetaceans • Negative correlations were found between length and TEQ values in franciscanas.• PCB concentrations found are among the highest ever reported for cetaceans. a b s t r a c t a r t i c l e i n f o Blubber samples from three delphinid species (false killer whale, Guiana and rough-toothed dolphin), as well as liver samples from franciscana dolphins were analyzed for dioxins and related compounds (DRCs). Samples were collected from 35 cetaceans stranded or incidentally captured in a highly industrialized and urbanized area (Southeast and Southern Brazilian regions). Dioxin-like PCBs accounted for over 83% of the total TEQ for all cetaceans. Non-ortho coplanar PCBs, for franciscanas (82%), and mono-ortho PCBs (up to 80%), for delphinids, constituted the groups of highest contribution to total TEQ. Regarding franciscana dolphins, significant negative correlations were found between total length (TL) and three variables, ΣTEQ-DRCs, ΣTEQ-PCDF and ΣTEQ non-ortho PCB. An increasing efficiency of the detoxifying activity with the growth of the animal may be a plausible explanation for these findings. This hypothesis is reinforced by the significant negative correlation found between TL and PCB126/PCB169 concentration ratio. DRC concentrations (ng/g lipids) varied from 36 to 3006, for franciscana dolphins, as well as from 356 to 30,776, for delphinids. The sum of dioxin-like and indicator PCBs varied from 34,662 to 279,407 ng/g lipids, for Guiana dolphins from Rio de Janeiro state, which are among the highest PCB concentrations ever reported for cetaceans. The high concentrations found in our study raise concern not only on the conservation of Brazilian coastal cetaceans, but also on the possibility of human health problem due to consumption of fish from Brazilian estuaries.

POPs in free-ranging pilot whales, sperm whales and fin whales from the Mediterranean Sea: Influence of biological and ecological factors

“…Also ΣPCDD/Fs and ΣDL-PCBs values of our two toothed-whales were exceeding concentrations found in Tasmanian sperm whales and long-finned pilot whales, in harbour seals from British Columbia and harbour porpoises from the Skarregat-Kattegat (Table 4; Bergreena et al, 1999;Ross et al, 2004;Gaus et al, 2005). Noteworthy, both sperm whales and pilot whales presented the same concentration ranges of ΣPCDD/Fs, and higher levels of ΣDL-PCBs, than Franciscana dolphins from the Guanarama Bay in Brazil which, due to the particularly heavy urbanization of that area, are exposed to massive levels of toxic substances and are, nowadays, considered as one of the most polluted cetacean in the world (Dorneles et al, 2013).…”

“…The use of TEFs to achieve TEQ constitutes an accurate procedure for the assessment of the toxic risk associated with a complex mixture of pollutants that are capable of triggering Aryl hydrocarbon (Ah) receptor mediated effects, such as DLCs (Dorneles et al, 2013). This method permits to operate risk assessment of cetaceans based on the different contribution of each pollutant to the total TEQ (Van der Berg et al, 2006).…”

Spatial variation in the accumulation of POPs and mercury in bottlenose dolphins of the Lower Florida Keys and the coastal Everglades (South Florida)

“…The most important contribution for the toxicity equivalences of PCDD/Fs and DL-PCBs expressed as TEQ in LFK and FCE dolphins are mainly provided by DL-PCBs (81% LFK -65% FCE), similar to Guiana dolphins (Sotalia guianensis) from Guanabara Bay Brazil where DLPCBs represented 98.8% of the total TEQ (Dorneles et al, 2013). The past use of PCBs (NDL-PCBs and DL-PCBs) in industry drives the observed pattern, while PCDD/Fs are produced mostly released by combustion reactions.…”

Levels, Trends, and Health Effects of Dioxins and Related Compounds in Aquatic Biota

“…PCBs can easily reach higher concentrations in predator species at the upper trophic levels [22,23] and are the predominant contaminants in most wildlife populations today [24,25]. High levels of dioxins and PCBs have been detected in dolphins [26][27][28], harbor seals (Phoca vitulina) [25,29,30] Fig. 1 Structures of dioxin and dioxin-like halogenated compounds northern fur seals (Callorhinus ursinus) [31], hooded seals (Cystophora cristata) [32], Steller sea lions (Eumetopias jubatus) [33], sharks [27,34], predatory birds [28,35], and human tissues [28,[36][37][38].…”