URBAN AIR-POLLUTION ENHANCES THE FORMATION OF URETHANE-INDUCED LUNG-TUMORS IN MICE

This paper investigates the association between air pollution and lung neoplasia in an animal model. The experimental exposures were done in two locations with different air pollution profiles: a polluted area (downtown Sao Paulo) and a ''clean'' environment (Atibaia). Swiss mice were employed and urethane (3 g/kg) was used as carcinogenic substanc e. Two experiments were performed: Experiment I was designed to verify whether air pollution acts as initiator and/or promoter of lung cance r, using 300 mice; Experiment II employed 250 animals and aimed to ver ify if the effects of air pollution on the development of lung tumors was dose dependent. A significant effect of air pollution in augmentin g lung carcinogenecity induced by urethane was observed. This effect w as shown to be dose-dependent and reproducible on two different occasi ons. In addition, morphometric studies revealed that pollution may inf luence tumor phenotype. These results support the hypothesis that air pollution plays a significant role in the development of lung tumors. (C) 1997 Academic Press.