containing 2 , 3 , 7 ,8-tetra-CDD concentrations between 0.050 and 

 0.025 ng/g wet weight. 



No studies have been conducted on the bioaccumulation 

 from sediments of 2 , 3 , 7 , 8-tetra-CDD in marine organisms. 

 However, Kuehl et al. (1987) found that the freshwater fish 

 f Cyprinus caprio ) collected from an area that had a sediment 

 2, 3, 7, 8-tetra-CDD concentration of 0.17 ng/g contained 0.12 ng/g 

 dry weight of this compound. Using only this data, extrapolating 

 to BRH Wetland sediment levels and converting dry weight to wet 

 weight concentrations (assuming a wet/dry ratio of 4) would 

 predict a level of about 0.008 ng/g wet weight for fish 

 constantly exposed to BRH Wetland sediment. This is below the 

 FDA "Levels of Concern" of 0.02 5 ng/g. Obviously, however, this 

 is only a highly speculative paper excercise which should only be 

 used as a very rough estimate. 



CONCLUSIONS 



The toxic compound, 2 , 3 , 7 , 8-tetra-CDD, was detected in 

 the BRH Wetland sample at a level of 0.04 3 ng/g, and was below 

 the detection limits for the other four samples tested. The 

 concentration of 2 , 3 , 7, 8-tetra-CDD measured in the BRH Wetland 

 sediment in this study is well below the level of 1 ng/g for soil 

 listed by the Center for Disease Control as a level that 

 constitutes a potential health risk. 



Numerous PCDD and PCDF compounds were detected in all 

 of the five samples analyzed in this study (BRH Original 

 Composite, BRH Wetland, BRH Upland, 200 East and South 

 Reference) . The levels of PCDDs and PCDFs at the South Reference 

 station are relatively low and probably represent general 

 background levels resulting from the atmospheric and riverine 

 deposition of these compounds. The levels measured in the BRH 

 Original Composite, BRH Wetland and BRH Upland samples were 

 considerably higher than those of the South Reference sediments. 

 The sediment sample found to have the highest PCB concentrations 

 at the FVP disposal site on the last FVP Study sampling date 

 (10/22/85) ,the 4-6 cm sediment core section from 200 meters East 

 of the disposal buoy, contained PCDD and PCDF concentrations only 

 slightly above the levels measured in the South Reference sample. 



The source of PCDDs and PCDFs to Black Rock Harbor is 

 not known. However, the congener ratios indicate that combustion 

 processes may be the major source of these compounds. 



If 2, 3, 7, 8-tetra-CDD in Black Rock Harbor sediment 

 behaved similarly to what Kuehl et al. (1987) reported in a 

 bioaccumulation study using freshwater fish and sediment, fish 



13 



