Distribution and sources of PCBs (Aroclor 1268) in the Sapelo Island National Estuarine Research Reserve

Abstract

Aroclor 1268 is a highly chlorinated PCB mixture that was released into the aquatic environment near Brunswick, GA (BR), as a result of decades of local industrial activity. This extensive contamination has led to US EPA Superfund designation in estuarine areas in and around Purvis Creek, GA. Roughly 50 km to the northeast is the Sapelo Island National Estuarine Research Reserve (SI) where previous studies have documented unexpectedly high Aroclor 1268-like PCB levels in blubber and plasma samples of resident bottlenose dolphins. This result led to a collaborative effort to assess the PCB patterns and concentrations in SI sediment and fish (as potential vectors for PCB transfer to SI resident dolphins). Thirty SI randomly assigned stations were sampled for sediment PCB levels. Additionally, fish were collected and analyzed from SI (n = 31) and BR (n = 33). Results were pooled with regional assessments of PCB concentrations from South Carolina and North Carolina in an effort to determine the association of Aroclor 1268 levels in SI samples. Results indicated that PCB levels in sediment and fish are much lower in the SI estuary compared to BR sediment and fish concentrations. However, PCB congener profiles for both sediments and fish were similar between the two locations and consistent with the Aroclor 1268 signature, indicating possible transport from the Brunswick area. A likely source of Aroclor 1268 in dolphins from SI is contaminated fish prey.

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

“…6). The highest PCB concentrations have been described in bottlenose dolphins from Brunswick, GA where Aroclor 1268-a highly chlorinated PCB mixture-was released into the aquatic environment during decades of local industrial activities Kucklick et al, 2011;Wirth et al, 2014). In our study region, the S 6 NDL-PCBs concentrations were low compared to other locations in the southeastern US.…”

Enzyme induction and histopathology elucidate aryl hydrocarbon receptor–mediated versus non–aryl hydrocarbon receptor–mediated effects of Aroclor 1268 in American mink (Neovison vison)

“…The congener profile of Aroclor 1268 neat material is similar to that in Turtle‐Brunswick River estuary sediments and biota . For instance, the 6 most prevalent congeners in the diets of Aroclor 1268–treated mink (PCBs 209, 207, 206, 202, 194, and 187) were among the 10 most prevalent reported in Turtle‐Brunswick River estuary sediments in relatively similar ratios with some exceptions . Reductive dechlorination of PCBs by sediment bacterial communities and metabolic biotransformation throughout trophic levels can alter the composition of PCBs released into the environment from industrial operations, potentially changing the toxic potency of Turtle‐Brunswick River estuary sediments relative to unweathered Aroclor 1268.…”

“…Lipids were resuspended in hexane, and the solution was cleaned with sulfuric acid and an acidic/ neutral silica gel column. Extracts were concentrated to 1 mL, and 61 PCB congeners were quantified at the Michigan State University Wildlife Toxicology Laboratory by gas chromatography (Hewlett-Packard 5890 Series II) equipped with a 30-m Phenomenex ZB-Multiresidue-1 column with 0.25 mm inner diameter and a 63 Ni electron capture detector (GC-ECD). Injection volume was 1 mL, helium gas was used as the carrier, and detector temperature was maintained at 390 8C.…”

Persistent organic pollutants (POPs) in blubber of common bottlenose dolphins (Tursiops truncatus) along the northern Gulf of Mexico coast, USA

“…A major route of exposure and accumulation of POPs in dolphins is from consumption of contaminated prey, and contaminant levels of dolphin prey species vary depending on numerous factors including trophic level, distribution patterns, and proximity to contaminant sources (e.g. Storelli et al, 2006;Wirth et al, 2014). The higher levels of POPs measured in dolphins sampled around the barrier islands may be a result of differences in dolphin prey selection and variations in prey species' contaminant levels between the estuarine and coastal waters.…”