Tumors and amyloidosis in mice painted with crude oil found on bathing beaches.

Oil lumps collected on the beaches of Israel in 1970, 1971 and 1973 were extracted with pure acetone and the extracts were used to paint the skin of mice twice weekly for 12 months. The oil lumps originated from crude oil spilled from tankers. The less recently collected oils induced papillomata and lymphomata in some animals. They were also more active than the recent oil in the induction of generalized amyloidosis. Mice painted for 12 months with acetone alone developed amyloidosis to a similar extent as those painted with the oldest oil. In previously reported experiments, however, acetone was much less active than the oil in producing amyloidosis after 5 months of painting. The possibility that acetone and oil might act both synergistically or to be antagonistic at different phases of amyloidogenesis is discussed.