Impacts from PCB Accumulation on Amphibians Inhabiting Streams Flowing from the Paducah Gaseous Diffusion Plant

Abstract

Contamination at the Paducah Gaseous Diffusion Plant (PGDP), Paducah, Kentucky, has been under evaluation for many years. We studied amphibians in selected outfalls (drainage ditches) flowing from the PGDP to determine if PCBs were accumulating in their tissues and how this might affect local populations. We determined relative amphibian species richness and abundance among seven outfalls and three reference streams by listening to their calls during audio surveys. We also captured amphibians from each study site during the summers of 2000 and 2001 and analyzed their carcasses for PCBs (Aroclor 1260 and 34 congeners) and livers for ethoxyresorufin O-deethylase (EROD) activity, a biomarker of PCBs and other organic contamination. Ten species were heard across study sites, and abundance and richness at outfalls were similar to those observed at reference sites. However, there were significant differences in abundance (p = 0.001) and richness (p = 0.048) of amphibians between continuously flowing and intermittent outfalls. There were no significant differences in PCB concentrations (p = 0.113) in amphibians captured from study sites, although Aroclor 1260 concentrations tended to be higher in amphibians collected from one outfall (outfall 12) on the east side of the plant (x = 1260 microg/kg) compared with all other study sites (x = 489 microg/kg). EROD activity measured in the liver was not indicative of Aroclor 1260 concentrations in amphibians at the PGDP, and EROD did not differ by study site, species, age class, or gender. PCB concentrations measured in amphibians at the PGDP were similar to concentrations measured at reference sites and did not appear to negatively affect individual amphibians or abundance and richness.

Field exposure of frog embryos and tadpoles along a pollution gradient in the Fox River and Green Bay ecosystem in Wisconsin, USA

“…Our conclusions do not rely heavily on that value, because when it is omitted, the regression of total PCBs is still highly significant ( F 1,9 = 14.1, p = 0.003) and the numerical values of the fitted slopes and intercepts change by only 7% and 1%, respectively. Our analysis of variation in contaminants across sites also would be stronger if we had more replication of sediment samples and tissue pools at each site, which might yield more accurate means and estimates of intrasite variability [38–40]. The r 2 value of 0.69 for adults and juveniles in Figure 6B suggests that additional research may uncover other significant factors in addition to sediment PCB levels and stage that determine bioaccumulation in frogs, such as aerial inputs from industrial wastes and fires [41,42].…”

Accumulation of Polychlorinated Biphenyls (PCBs) and Evaluation of Hematological and Immunological Effects of PCB Exposure on Turtles

“…Concentrations of Aroclor 1245 and total PCBs in fish tissue collected during 1989 from Little Bayou Creek, which flows along the eastern edge of the PGDP, were 2.196 and 4.843 mg/kg, respectively. A more recent study conducted by DeGarady and Halbrook (2003) reported that concentrations of Aroclor 1260 ranged from 0.151 to 4.470 mg/kg ww in various anuran species collected from PGDP outfalls. Because PCBs may pose a risk to aquatic biota inhabiting the PGDP area, studies are needed to assess current PCB exposure and its potential effects on aquatic organisms.…”