SINDERMANN: POLLUTION-ASSOCIATED DISEASES AND ABNORMALITIES 



erosion were studied simultaneously in Dover sole 

 from the California coast. Fin erosion was more 

 common in specimens collected near major sewer 

 outfalls, whereas tumorous fish were distributed 

 more evenly throughout southern California 

 coastal waters. The authors concluded that "The 

 spatial and temporal distribution of tumor- 

 bearing Dover sole suggest that initiation of the 

 disease was not related to [municipal] wastewater 

 discharges [in southern California]." 



A recent report of neoplasms in the Atlantic 

 hagfish, Myxine glutinosa, by Falkmer et al. (1977) 

 suggested a possible relationship of PCB contami- 

 nation and tumor prevalence. During a 5-yr 

 (1972-76) study in Gullmar Fjord, Sweden, neo- 

 plasm prevalences, particularly hepatomas, de- 

 creased from 5.8 to 0.6'^ . PCB levels in livers of 

 hagfish were appreciable (5 ppm), but the use of 

 PCB was prohibited in 1971. Liver PCB levels in 

 hagfish caught inside the Qord were five times 

 higher than in those caught outside. However, the 

 association of PCB contamination with liver 

 tumors must be considered to be tenuous. Earlier 

 reports of neoplasms in hagfish (Fange etal. 1975; 

 Falkmer et al. 1976) described remarkably high 

 frequencies in Gullmar Fjord, but only low con- 

 centrations (0.5-1.0 ppm) of PCB in livers, and low 

 environmental levels of PCB and other contami- 

 nants. 



The role of environmental chemical factors in 

 induction of neoplasms in shellfish is even less 

 clear than for fish, but there is some limited infor- 

 mation. Yevich and associates (Barry and Yevich 

 1975; Yevich and Barszcz 1976, 1977) have for a 

 number of years examined the occurrence of neo- 

 plastic growths in the soft-shell clam, Mya 

 arenaria, in relation to petroleum contamination. 

 Gonadal and hematopoietic neoplasms were ob- 

 served in animals collected from two chronically 

 contaminated sites on the Maine cost, with pre- 

 valences up to 29% in certain samples. Yevich and 

 Barszcz (1976) stated that "no tumors similar to 

 those described [from the petroleum contaminated 

 area] have been encountered in animals collected 

 from any other area." They described the scope of 

 their study as "several thousand animals from all 

 coastal areas of the United States." Additional 

 samples of clams from a number of other coastal 

 locations are needed, as is a more precise descrip- 

 tion and confirmation of the neoplastic condition. 



It is interesting that a counterpart study of 

 soft-shell clams from Rhode Island and Mas- 

 sachusetts (Brown et al. 1976) reported occur- 



rences of neoplasia, apparently of hematopoietic 

 origin, in up to 26% , with the highest frequency in 

 samples from a 1975 oil spill area near Bourne, 

 Mass. A later report (Brown et al. 1977) included 

 additional samples from other geographic areas. 

 Neoplasms of gonadal origin, similar to those re- 

 ported by Yevich and associates, were found in 

 clams from an oil-contaminated site at Searsport, 

 Maine. The highest prevalence of neoplasms of 

 hematopoietic origin was 64% , in a small sample 

 from Bourne. The authors pointed out, however, 

 that clams from some oil-contaminated sites had 

 no neoplasms, and stated that "These results 

 suggest that the type and degree of hydrocarbon 

 pollution are possibly related to the frequency of 

 neoplasms and other lesions in Mya, but they are 

 by no means the only causative factors." 



Other types of cellular abnormalities have been 

 reported from soft-shell clams. In earlier studies 

 by Yevich and associates (Barry et al. 1971) 

 atypical epidermal hyperplasia in gills and kidney 

 was reported in up to 40% of clams sampled near 

 Providence, R.I. Lesions occurred more frequently 

 in large individuals, and seasonal changes were 

 not observed. Lower prevalences were found in 

 limited samples from Maine, Maryland, and 

 California. Unlike the oil spill studies, no associa- 

 tion with environmental factors was made by the 

 authors. 



Yevich and associates (Yevich and Barry 1969; 

 Barry and Yevich 1972) have also described 

 gonadal neoplasms in quahogs, Mercenaria mer- 

 cenaria, from Narragansett Bay. Samples col- 

 lected in 1968, 1969, and 1970 had tumor frequen- 

 cies of 0.2, 2.3, and 2.7% respectively. 



Epizootic neoplasms with a possible environ- 

 mental etiology were reported from several mol- 

 luscan species of Yaquina Bay, Oreg. (Farley 

 1969b; Farley and Sparks 1970; Mix et al. 1977). 

 Blue mussels, Mytilus edulis, native oysters, 

 Ostrea lurida, and two species of Macoma were 

 affected, and winter mortalities were associated 

 with the disease. Neoplasms have not been found 

 in bivalve molluscs sampled elsewhere on the 

 Oregon coast (Mix et al. 1977). 



In another study (Christensen et al. 1974) simi- 

 lar epizootic neoplasms (up to 10% prevalence) 

 were found in a localized population of the clam 

 Macoma balthica from a tributary of Chesapeake 

 Bay. The neoplasms were invasive and systemic, 

 with initial foci in the gill epithelia. Holding ex- 

 periments indicated that the disease was usually 



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