PARENT SESSION

1J - Bioaccumulation
Poster Hall
8:30 AM - Wednesday, 30 April 2003
Chair: Tarazona, J.¹, ¹
Co-chair: Gobas, F.², ²

(WEP/72) Accumulation of PCDDs, PCDFs and PCDEs from the polluted river sediment to organisms and SPMDs.

Kukkonen, Jussi¹, Lyytikäinen, Merja¹, Rantalainen, Anna-Lea², Minkkinen, Pentti³, Hirva, Pipsa ⁴, Hämäläinen, Heikki ⁵, Mikkelsson, Pirjo ⁶, Paasivirta, Jaakko⁶, ¹ Department of Biology, University of Joensuu, Joensuu, Finland² Department of Ecological and Environmental Sciences, University of Helsinki, Lahti, Finland³ Lappeenranta University of Technology, Lappeenranta, Finland⁴ Department of Chemistry, University of Joensuu, Joensuu, Finland⁵ Karelian Institute, University of Joensuu, Joensuu, Finland⁶ Department of Chemistry, University of Jyväskylä, Jyväskylä, Finland

ABSTRACT- Sediment and chironomid samples were collected from ten sites of river Kymijoki downstream from a closed chlorophenol production plant. Accumulation of polychlorinated dibenzo-p-dioxins and furans (PCDD/F) and polychlorinated diphenyl ethers (PCDE) from the sediments to oligochaeta, Lumbriculus variegatus, and semipermeable membrane devices (SPMDs) was studied in a 28-d bioaccumulation test. The results were compared to the concentrations analyzed from the field-collected chironomids. Concentrations accumulated by SPMDs reflected well the sediment concentrations (r_p = 0.89 and 0.67, for PCDD/Fs and PCDEs, respectively, p < 0.001). SPMDs were found to give a fair estimate of bioaccumulation in benthic oligochaetes (r_p = 0.90 and 0.65 for PCDD/Fs and PCDEs, respectively, p < 0.001), when octachlorinated congeners were excluded. In comparison of laboratory test with naturally exposed chironomids, similarities in bioaccumulation patterns were found; statistically significant correlation to laboratory exposed oligochaetes was for both PCDD/Fs (r_p= 0.69, p< 0.001) and PCDEs (r_p = 0.49, p < 0.001). To find out the factors that may affect the bioavailability of these chemicals in sediments, the partial least square regression analysis was used. The studied factors included both physical-chemical and structural characteristics of the contaminants (water solubility, lipophilicity, dipole moment, molecular size and conformation) and sediment characteristics (organic carbon content, aromaticity and polarity of organic carbon, particle size). The obtained results indicated that lipophilicity/water solubility affects significantly bioaccumulation of both PCDD/Fs and PCDEs. Further, molecular volume and factors that promote sorption played an important role. The studied factors contributed up to 65 - 85 % of the variation in bioaccumulation data for SPMDs emphasizing the chemical nature of the process. For oligochaetes, only 50 - 65 % of the variation was explained, which indicates the importance of biological factors on bioaccumulation.

Key words: sediments, bioaccumulation, PCDD/Fs, PCDEs