[Experimental study of the aftereffects of feeding rats certain types of canned fish]

For 3 years fish canned goods were added to the ration of rats. These additions included atlantic herring in tomato gravy ("Stavrida"), dressed sprat in tomato gravy (sprats-small-sized) or sprat in vegetable oil ("Sprat"). Rats receiving canned "small-sized sprats" or "sprats developed much more often malignant tumors of different localization than did the animals fed on "Stavrida" or control rats. Feeding of rats on the vegetable oil from "stavrida" and "sprat" cans did not have any material effect on the development of tumours. Introduction of these samples of oil together with the food or parenterally to mice did not have any substantial influence on the development in them of skin tumors, induced with benzpyrene. The canned goods under investigation, especially of the "sprat" kinds, demonstrated small amounts of benzpyrene and carcinogenic nitroso-compounds.