Newark Bay 



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200 400 600 800 



fluoranthene, ug/goc 



1000 



*— T 



1200 



Figure 45. Relationship of amphipod survival to the 

 concentrations of fluoranthene in Newark Bay sediment 

 samples. 



exceeded the ERM value of 180 ng/g (Long et al., 1995) in all except three samples, and most of these 

 samples were highly toxic to the amphipods (Figure 38). Total PCB concentrations ranged from 105.5 

 to 2,850.2 ng/g (median = 879.2 ng/g). Amphipod survival was zero in a sample with approximately 

 1 ,400 ng tPCB/g. MacDonald ( 1 994) estimated the SEC for total PCBs as 0.592 mg/kg dry wt (592 ng/ 

 g). All of the samples that equalled or exceeded a total PCB concentration of 592 ng/g caused 50% or 

 less amphipod survival. One sample had over 2,800 ng tPCB/g and caused less than 40% amphipod 

 survival. It appears that the PCBs may have made a major contribution to the toxicity to the amphi- 

 pods. 



The concentrations of four co-planar PCBs were normalized to (multiplied by) the toxicity equivalency 

 factors (TEFs) (Barnes et al., 1991) for each congener and the sums of those quotients were calculated. 

 The cumulative toxicity equivalency quotients (TEQ) for the co-planar PCBs were highly correlated 

 with amphipod survival (Figure 39). There is no consensus toxicity threshold value for these quotients. 

 Many different estimates have been made of critical or threshold values and they differ from each other 

 by many orders of magnitude (Iannuzzi et al., 1995). In two samples the cumulative TEQs for the PCB 

 congeners were higher than one estimate of a threshold, 100 pg/g for fish and human receptors (U.S. 

 EPA, 1993; New York State DEC, 1993, respectively), but the reliability of this threshold value is 

 unknown. The sample from station 26 caused 100% amphipod mortality and had about 140 pg/g 

 cumulative TEQs for the co-planar PCBs. Among all the chemicals quantified, only the concentrations 

 of these compounds and p,p'-DDE were highest in the sample from station 26 where amphipod sur- 

 vival was zero. 



106 



