The concentrations of total PCBs were higher than the concentrations of 

 DDTs or other CHs in 18 of the 19 blubber samples; the same pattern was 

 observed for liver samples (Figure 3). However, one animal (MS 018) from the 

 Mississippi coast had DDT concentrations higher than PCBs in blubber (Figure 3, 

 Table 4). In addition, the liver of a dolphin (SCHM 077) from the Alabama coast 

 had considerably higher levels of DDTs than PCBs — no blubber sample was 

 available from this animal. 



The ratio of the concentrations of p,p'-DDT to p,p'-DDE ranged from 0.01 

 to 0.62 in blubber tissue from these 20 dolphins (Table 7) with three dolphins 

 having a ratio of p,p'-DDT to p,p'-DDE that was greater than one-tenth (e.g. PO 

 095, 0.62; GA 344, 0.12; MS 018, 0.11) indicating a presence of an unusually 

 high proportion of unmetabolized DDT. 



Quality Assurance Measures for Metals and Chlorinated Hydrocarbons 



Mean recovery of metals from CRMs was 104 ± 3^ % and the analyses of 

 replicates agreed within ± 6 %. The grand mean recovery (120 ± 19 %) was 

 calculated from the mean recoveries for ceitain CH analytes in SRM 1974 by 

 calculating the ratio of the concentrations of analytes from this series (n = 4) to 

 those of previous analyses (n = 9). Variabilty increased as the concentrations of 

 analytes approached trace levels (Horwitz et al. 1980). Replicate analyses (n = 2) 

 agreed within ± 12 %. The mean recovery for the surrogate standards (n = 48) 

 was 84 % with a relative standard deviation (RSD) of 17 %. 



DNA'Xenobiotic adducts in Liver 



Liver samples were analyzed for levels of DNA-adducts. The fmdings 

 suggest that the length of time between death and sampling of liver may 

 compromise the quality of the data. For DNA-adducts, the results showed that, in 

 dolphins sampled at times > 1 day after death, the level of DNA-adducts were 

 lower than the levels in dolphins sampled at < 1 day after death. 



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