ABSTRACT
The cell transformation test has permitted the correct classification of the biological activity of 94 percent of 120 compounds tested, including polycyclic aromatic hydrocarbons, arylamines, and alkylating compounds. The primary method for investigation of the biological activity of substances in the respiratory tract is intratracheal instillation. The toxin can be absorbed through the gastrointestinal tract, the respiratory tract, or the skin. A number of different methods for the experimental induction of tumors in the respiratory tract by polycyclic aromatic hydrocarbons have been developed. Intratracheal instillation is a relatively simple technique, and therefore is frequently used in the testing of chemicals which are potentially carcinogenic to the respiratory tract. Tumors developing in the upper region of the respiratory tract can be autotransplanted into the lung by repeated intratracheal manipulation. Tumors were detected predominantly in the pharynx, epiglottis, and larynx. The subcutaneous test is reviewed in a more narrow sense concerning the induction of tumors at the site of application.
