(the axis of predominant current movement) , it is expected that 

 the off-mound transect stations would show higher contaminant 

 levels than the reference station. 



As a second approach to addressing the question of 

 contaminant transport, a statistical test (Kruskal-Wallis test) 

 was performed to determine differences in contaminant 

 concentrations among the five transect stations (1500NW, 400NW, 

 CTR, 400SE and 800SE) . This test showed that for those 

 contaminants which were detected (As, Cu, Fe, and Pb) , there was 

 no significant difference in concentrations among the five 

 stations. As the next step, for each of these metals the 

 replicate values obtained at the five transect stations were 

 pooled and tested against the three replicate reference values 

 (two in the case of Hg) . This test (Mann-Whitney U-test) showed 

 that there was no significant difference in the metal 

 concentrations between the reference station and the pooled 

 transect stations. The fact that the transect stations do not 

 differ from each other and collectively do not differ from the 

 reference station strongly suggests that resuspension, transport, 

 and redeposition of the contaminants is not occurring. 



4.5 Body Burden Analysis 



Reflecting the pattern of sediment contaminant levels, 

 Leptocheirus body burdens at stations in and around the disposal 

 site were generally below detection limits or were significantly 

 less than or not different from those at NLON-Ref. The exceptions 

 to this are various elevations of Pb, Cu, and Fe at stations 

 CTR#2, 400SE and 1500NW (Table 3-6). The variations between CTR#1 

 and CTR#2 in Pb, Cu, and Fe levels are notable. However, based on 

 the excellent recovery for these elements from spiked laboratory 

 quality assurance procedural blanks (Pb = 88%, Fe = 99%, Cu = 

 99%) , the results reflect station population variability as 

 opposed to analytical inconsistencies. 



The objective of the body burden analyses was to assess 

 the relationship between sediment contamination and biological 

 uptake. This relationship was examined for Pb, Cu, and Fe, the 

 only three contaminants displaying both body burdens and sediment 

 concentrations significantly above detection limits. The results 

 of a nonparametric test for association (Spearman's coefficient of 

 rank correlation) show that the mean body burden concentrations of 

 Fe and Cu are not significantly associated with the mean sediment 

 concentrations of these metals (Spearman's rho =0.66, P > 0.05 

 for both metals) . There was some suggestion of a significant 

 association between mean body burdens and sediment concentrations 

 of Pb (Spearman's rho = 0.81, P = 0.051), but the small sample 

 size in conjunction with the uncertain exposure history of the 

 test organisms implicit in studies of this nature render any 

 definitive conclusions tenuous. 



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