STEIMLE ET AL.: ORGANIC AND TRACE METALS IN OCEAN QUAHOG 



Table 2.— PAH (polynuclear aromatic hydrocarbon) levels in northwestern Atlantic 

 Arctica islandica (ng/g wet weight). 



Wet weight concentrations = dry weight concentration 4- 7. 



N = naphthalene. 



IN = total naphthalenes (C -CJ. 



P = phenanthrene. 



IP = total phenanthrenes (Cq-CJ. 



IDBT = total dibenzothiophenes (C -C 3 ). 



IF = total fluorenes (C -C 3 ). 



1202 = fluoranthene + pyrene. 



1228 = benzanthracene + chrysene. 



1252 = benzofluoranthenes + benzopyrenes. 



B(a)P = benzo(a)pyrene. 



nd = not detected (<1 ng/g wet weight). 



dd, . . , *N + IDBT + (IP-P) + IF 



PPI = percent petroleum index = 



IPAH =3M + IP + IDBT 

 'From Boehm (1983a). 



+ IF + 1202 



IPAH 

 1252 + 1228 



TV-ends in the PHC and PAH data reveal large-scale 

 homogeneity in the concentrations observed. PAH 

 levels ranged from nondetectable to 55 ppb, the high- 

 est values occurring at the station 32 samples from 

 the New York Bight, where the highest PCB level 

 (27 ppb) was also observed. Although our sampling 

 on Georges Bank consisted of only one station, 

 results were similar to those of a more extensive 

 study by Payne et al. (1982), the only other study 

 of A. islandica we could locate that includes PHC 

 data. If the entire Northeast region is considered a 

 sample set, then the PAH values were 16.7 ± 12.0. 

 However, the composition of the PAH which com- 



prises the total PAH number varied considerably, 

 ranging from to 81% "petroleum" PAH (Table 2). 

 The percent petroleum index (PPI), developed by 

 Boehm (1983a, b), estimates the relative contribu- 

 tions of uncombusted fossil fuels, eg, petroleum, and 

 from combustion sources to the total PAH assem- 

 blage This indice, presented in Table 2, is based on 

 the relative abundance of petroleum constituents, 

 such as naphthalene, flourenes, dibenzothiophenes, 

 and alkylated phenanthrenes, to the total PAH mix. 

 The differences in PPI values for the various samples 

 cannot, at this time, be ascribed to specific trans- 

 port or selective uptake factors. However, a knowl- 



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