CARCINOGENICITY STUDY OF OUTDOOR AIRBORNE PARTICULATE MATTER IN NEWBORN MALE NMRI MICE

An organic extract of airborne particulate matter (APM) was tested for carcinogenicity at two dose levels in the newborn mouse bioassay. The samples used were taken under specific polluted conditions. The doses tested corresponded with 0.75 and 1.5 times the amount of air man inh ales during lifetime. Benzo(a)pyrene, which was used as a positive con trol, significantly increased the lung tumor incidence. No evidence wa s found for a carcinogenic activity of the organic extract of APM. Con sidering the high dose of APM applied in this animal model and the muc h lower actual cumulative dose to which man is exposed to in many area s, the conclusion can be drawn that exposure to APM alone probably doe s not represent an important cancer risk for man.