Table 20 continued. 



*p<0.05, **p<0.001, ***p<0.0001 



The concentrations of some substances equalled or exceeded the respective ERM guideline values of 

 Long et al. (1995) or Long and Morgan (1990), or the proposed National SQC of U.S. EPA (1994) in 

 some of the samples. The ERM guidelines are the concentrations above which toxicity or other effects 

 frequently occurred in previous studies (Long et al., 1995). The SQCs are the concentrations deter- 

 mined by equilibrium-partitioning models to be protective of benthic organisms. In this study, it was 

 assumed that substances that were correlated with toxicity and equalled or exceeded either the respec- 

 tive ERM or SQC values may have contributed to the observed toxicity. Table 19 summarizes the 

 frequency of guideline exceedances for those chemicals or classes of chemicals that indicated a signifi- 

 cant negative correlation with toxicity in at least one of the tests. 



None of the samples had concentrations of silver, arsenic, or cadmium that equalled or exceeded the 

 respective ERM values (Table 21). The ERM value for chromium was exceeded only in one sample 

 (12a from the East River). The guideline values for mercury, p,p'-DDT, p,p'-DDE, fluoranthene, 

 phenanthrene, and total high molecular weight PAHs were equalled or exceeded most frequently. Al- 

 though the ERM value for mercury was exceeded in 30 samples, Long et al. (1995) reported only a 

 moderate degree of confidence in this guideline. The SQC values for fluoranthene and phenanthrene 

 were exceeded in many samples, often by a considerable amount. Many of the chemicals quantified in 

 samples 7b, 9b, lib, 12a, 17c, and 18c equalled or exceeded their respective guideline concentrations, 

 often by a factor of 2x or greater. 



Table 21. Samples from the Hudson-Raritan estuary (Phase 1) stations that equalled or exceeded 

 the respective ERM or SQC guideline concentrations for each major substance or class of com- 

 pounds. Stations in which the concentration exceeded the guideline by >2x are listed in bold 



(n=38). 



Number of samples Samples in which 



Chemical in which ERM or SQC the ERM or SQC 



substance values were exceeded was exceeded 



Silver (ERM=3.7 a ) 



Arsenic (ERM=70 a ) 



Cadmium (ERM=9.6 a ) 



Chromium (ERM-370 3 ) 1 12a 



83 



