Bioaccumulation and Toxic Potencies of Polychlorinated Biphenyls and Polycyclic Aromatic Hydrocarbons in Tidal Flat and Coastal Ecosystems of the Ariake Sea, Japan

Abstract

Sediment and marine biota comprising several species of tidal flat and coastal organisms were analyzed for polychlorinated biphenyls (PCBs) including non- and mono-ortho coplanar congeners and polycyclic aromatic hydrocarbons (PAHs) to examine bioaccumulation profiles and toxic potencies of these contaminants. Concentrations of PCBs in tidal flat organisms ranged from 3.6 ng/g (wet wt) in clams to 68 ng/g (wet wt) in omnivore tidal flatfishes, a discernible trend reflecting concentrations and trophic levels. In contrast, PAHs concentrations were the highest in lower trophic organisms, such as crabs and lugworms from tidal flat, whereas those in coastal fishes, squid, and finless porpoises were less than detection limit. Greater bioaccumulation of PAHs was found in lugworms and crabs, which might be due to their direct ingestion of sediment particulates absorbed with PAHs. TCDD toxic equivalents (TEQs) were calculated for PCBs and PAHs in sediments and biota. PCBs accounted for a greater proportion of total TEQs (sum(TEQs): sum of TEQ(PCB) and TEQ(PAH)) in coastal and tidal flatfishes (>95%), while PAHs occupied a considerable portion of sum(TEQs) in sediment (>97%). Interestingly, TEQ(PAH) accounted for 37% and 81% of the sum(TEQs) in crabs and clams, respectively. Benzo[b]fluoranthene was the dominant contributor to TEQ(PAH) in both the species. Considering these observations, the environmental risks of PAHs may not be ignored in benthic tidal flat organisms due to their greater bioaccumulation through sediments.

Dioxin-like compounds in agricultural soils near e-waste recycling sites from Taizhou area, China: Chemical and bioanalytical characterization

“…In the present study, REPs of PAHs obtained from in vitro bioassay using recombinant H4IIE cells Nakata et al, 2003), were used to estimate the TEQs contributed by individual PAHs. The calculated TEQ (TEQ cal ) was obtained as the sum of TEQs from the individual compounds (including PCBs, PCDD/Fs and PAHs) by assuming an additive effect when dioxin-like chemicals mixed.…”

Genotoxicity of the sediments collected from Pearl River in China and their polycyclic aromatic hydrocarbons (PAHs) and heavy metals

“…Some researchers had reported that PAHs were the predominant contributors to ΣTEQs in sediments, contributing 10-240 times greater TEQs than those by PCDDs/ DFs (Nakata et al 2003). Moreover, White (2002) and Landrum et al (2003) reported that the genotoxicity of the priority PAHs is additive, acting at the same molar concentration whether present as individual compounds or in mixture.…”

Water exposure assessment of aryl hydrocarbon receptor agonists in Three Gorges Reservoir, China using SPMD-based virtual organisms

“…The relative potencies (REPs) of PAHs related to TCDD were used to estimate TEQs contributed by individual PAHs (Villeneuve et al, 2002;Nakata et al, 2003). The TEQ cal was obtained as the sum of TEQs from the individual compounds of PAHs and PCBs.…”

“…TEQ bio was obtained by comparing the EROD activities of samples to the TCDD concentration-response curves. Table S1 by the corresponding REPs (relative potencies) proposed by references Villeneuve et al (2002) and Nakata et al (2003). TEQ cal is the sum of TEQ PAH and TEQ PCB .…”