Polychlorinated biphenyls (PCBs) were measured in surface sediments collected
three times (June, October, December, 2013), inside Jeju Harbor, Seogwipo
Harbor, Songsanpo Harbor, and Hallim Harbor (where a lot of steady shipping
occurs) as major harbors of Jeju Island. From the results, their horizontal
distribution and the correlation between PCBs concentrations and each of organic
carbon and particle size distribution were examined. In addition, their levels
were compared with the sediment quality guidelines applied in foreign countries
for PCBs. The results obtained were summarized as follows:
1. The concentrations of PCBs inside Jeju Harbor, Seogwipo Harbor, Songsanpo
Harbor, and Hallim Harbor, were in the range of 1.62∼4.45 (mean 2.65) ng/g
, 0.84∼4.23 (mean 2.03) ng/g, 0.10∼0.44 (mean 0.24) ng/g, 0.17∼0.73 (mean
0.41) ng/g on a dry weight basis, respectively, decreased in the following
sequences: Jeju Harbor> Seogwipo Harbor> Hallim Harbor> Songsanpo
Harbor, and the levels were very low, as compared with those in other areas
of the world.
2. In the analysis of PCBs homologue patterns, high-chlorinated PCB congeners
(above hexa-chlorinated congeners) were dominant in surface sediments
inside Jeju Harbor and Seogwipo harbor, indicating that their sources were
originated from shipping activity. However, in surface sediments inside
Songsanpo Harbor and Hallim harbor, it was difficult to assume their possible
sources because of different patterns with the stations or their indistinctive
patterns.
3. In the relationships between PCBs concentrations and organic carbon contents,
the significant correlations (r2= 0.8337, 0.8532, 0.7466, 0.7723 for Jeju Harbor,Seogwipo Harbor, Songsanpo Harbor, and Hallim Harbor, respectively) were
obtained, indicating that the distribution of PCBs was affected by the organic
carbon.
4. In the relationships between PCBs concentrations and particle size (mud, sand
and gravel) in surface sediments, PCBs concentrations were higher in the
sediments with higher mud content, indicating that higher PCBs were
distributed with increasing sediments of fine gradules.
5. The PCBs concentrations in surface sediments in this study were very low,
compared with ER-L (effect range-low) and TEL (threshold effects level)
among sediment quality guideleines (SQGs) applied in foreign countries, such
as USA, Canada, and Australia, etc), indicating that their biological effects on
the bottom organisms in marine environment were expected to be very low.