[Transplacental effect of benz(a)pyrene and pyrene]

The transplacental and direct effect of benzo(a)pyrene (BP) and pyrene on A and C57BL mice and their offspring was studied. BP proved to present blastomogenic danger for the offspring. In A mice offspring the greatest blastomogenic effect was expressed with the dose of 6 mg: lung tumours developed in 76.8% against 12.3% in the control (P less than 0,001). Tumours of the liver were revealed in the offspring of C57BL mice, chiefly in males. Their incidence with the dose of 12 mg of BP was 31.6% in males: and 9.1% in female; in the controls--1.2% in males, in the control females no tumours of the liver were observed. Noncarcinogenic analogue of BP--pyrene produced no blastomogenic effect.