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Cores and sediment traps collected from Kao-ping Canyon were used to reconstruct historical record of PAHs contamination and find out the possible sources, distributions, trends and flux of PAHs. The sedimentary record of PAHs shows that the average concentration of total PAHs was 310 ng/g dry wt. (264¡ã364 ng/g) which was lower than coasts of the other countries. According to diagnostic ratios and statistical analysis, we identify sources of PAHs and suggest that all up-cores were dominated by petrogenic sources, but all down-cores except for C980 and S1 were tended to pyrogenic or mixed sources. In contrast, both C980 and S1 were showed higher perylene/£UPAHs (%), which suggests that biogenic sources dominate in C980 and S1. In comparison with sediment quality guidelines (SQGs), the PAHs concentrations of all sediment cores weren¡¦t exceeded the criteria, which suggests that no evident adverse biological effects exist caused by PAHs in Kao-ping Canyon. It shows that the transition from coal to petroleum fuel use corresponding to the total concentrations of PAHs decrease recorded during 1893-1935 period in the sediment core. A PAHs concentration peak also recorded during the World War ¢º, 1893-1935. Because of increase of importing fossil fuel and the growth of heavy industrials in Kao-Ping area, the total concentrations of PAHs were shown evidence of increase again since 1950s in the core from Kao-ping Canyon. The average PAHs flux in the upper and lower mooring deployed in Kao-ping Canyon were 66 and 108 £gg/m2/d, respectively, which were higher than coasts of the other countries. The PAHs sources of sinking particles were dominated by petrogenic sources which were as similar sources as all up-cores.

Water, suspended particle and sediment samples from Kao-ping estuary were collected and measured for concentrations of polycyclic aromatic hydrocarbons (PAHs) during March 2004 and April 2005. In addition, sediments from neighboring coastal area were also analyzed to estimate distribution, transportation and possible sources of PAHs. Total PAH concentrations varied from 33.0 to 910 ng/g dry weight (dw) in coastal sediments, and diagnostic ratios reflect a mixed sources of petrogenic and pyrolytic inputs. Due to the contribution of Kao-ping River, spatial distribution of PAH concentrations at coastal sediments near river mouth varied dramatically. Results of hierachical cluster analysis showed that PAH concentration distribution was influenced by Kao-ping canyon, and biogenic source might be the major PAH source for offshore sediments. Total PAH concentrations in river sediment varied from 63.0 to 720 ng/g dw. Higher concentration was measured between the Water Main pipe and Shuang-yuan Bridge, and possible sources were from both petrogenic and pyrolytic sources. Sediment of Dung-gang harbour had highest concentration, 28,000ng/g dw, in this study, which was contributed from petrogenic sources due to its intensive boating activities. Except fluorene and phenanthrene in harbour sediments, individual PAH concentrations of other sediments are lower or near the Effect Range Low value, concentrations might lead to possible adverse effects upon organism. Total PAH concentrations varied from 5.0 to 82.0 ng/L in suspended particulate phase and from 5.5ng/L to 46.0ng/L in dissolved phase, respectively. Most of high molecular weight PAH concentrations (>5-ring PAHs) in dissolved phase were below method detection limits. The partition coefficients¡]Koc¡^values of PAHs were 1 to 2 orders higher than predicted values. It might be attributed to soot particles which have extremely high sorption capacities. Correlation coefficients between total PAH concentrations in sediments versus total organic carbon¡]TOC¡^ and fine particle content¡]<63£gm%¡^were significant ¡]R=0.575, 0.800, 0.851 and 0.657, P<0.01¡^. In addition, PAHs in suspended particulate phase and dissolved phase were also significantly correlated to particulate organic carbon¡]POC¡^ and dissolved organic carbon¡]DOC¡^, respectively. The distribution of calculated PAH concentrations from organic carbon was higher in surface water than bottom water. Unlike salinity, there was no decreasing or increasing trend of these concentrations among river samples. It is possible that contamination was not come from upstream, but from estuary area where plume was lifted and diffused upstream by neat seawater. The flux in Wan-da Bridge was higher than downstream estuary area that might be due to PAH concentrations reduction by sedimentation or degradation.

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