the macroscopically determined incidences of liver tumours were 1 % in control rats , 45 % , 4 % and 4 % following administration of ndea , 14 % , 3 % and 1 % following administration of npyr , 6 % , 5 % and 1 % following administration of ndela and 12 % , 4 % and 3 % following the combined administration of all three nitrosamines .
C0012200
ndea
C0028197
nitrosamines