[Non-bioavailability of carcinogenic polycyclic aromatic hydrocarbons contained in coal dust]

The aim of the study was to ascertain whether polycyclic aromatic hydrocarbons (PAHs) especially 3,4-benzo(a)pyrene, could be eluted from coal dust that comes into contact with biological fluids or crosses the skin barrier. A fine-grained coal dust with known PAH content was placed into contact with homogenized pig lung or human gastric juices, and also applied to monkey skin, using the cutaneous window method. The results demonstrate that, in the in vitro systems used, PAHs contained in coal dust are not eluted by lung homogenate or gastric juices, nor are they capable of crossing the skin barrier. These results justify and support the interpretation given to the results of experimental carcinogenicity studies on coal dust which never succeeded in demonstrating a higher incidence of cancer, particularly lung cancer, in treated animals.