Distribution of chlorobenzenes (CBs) was surveyed in the surface seawater of Ise Bay in Japan. The dissolved CBs and the adsorbed CBs on suspended particulates were monitored at 40 stations throughout the bay area. The dissolved CB levels in filtered seawater were high in an area from Yokkaichi on the west end of the bay toward Tokoname on the east coast in the cases of dichlorobenzenes (DCBs), trichlorobenzenes (TCBs) and tetrachlorobenzenes. These data showed that the pollutants discharged

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... r Yokkaichi Port were carried in the surface water by the stream caused by the Kiso, Ibi and Nagara rivers. The adsorbed CB levels on the suspended particulates did not show any particular distribution pattern in the bay and their correlations with the dissolved levels were low. The partition coefficients based on the organic carbon contents (log Koc) for DCBs and TCBs were low in the area from Yokkaichi to the front of Tokoname and high just outside of this area. These phenomena could be interpreted as follows:the relatively undiluted polluted plume with a higher dissolved concentration and lower log Koc value was located in the surface of the area from Yokkaichi to the front of Tokoname. Also, just outside of this plume, the dissolved levels decreased rapidly due to the diffusion while the adsorbed CBs did not desorb from the particulates as fast as the decrease in the dissolved CBs in the surrounding water. In spite of the relatively large site dependent variation of log Koc in the bay, the log Koc values averaged over certain bay area for each CB isomer correlated well with the octanol/water partition coefficient (log Kow) reported for those compounds. These showed that property of the compounds, namely log Kow, was the major controlling factor of log Koc in the field and observed relatively large variation of log Koc was probably due to the slow desorption of CBs from particulates.