R' Chanina, administrator of the Kohanim testified [concerning] four matters: In all the days of the Kohanim, never did they re-frain from burning [sacrificial] meat that had been contaminated by a derived tumah together with [sacrificial] meat that had been contaminated by an av hatumah, although [by doing so] they added tumah to its tumah.  R' Akiva added: In all the days of the Kohanim, never did they refrain from lighting oil that had become disqualified through a tevul yom in a lamp that had been contaminated by one who was tamei from a corpse, although [by doing so] they increased its tumah.