The cancerogenic chemical that has a very long latent period is -
High-Yield Explanation
Asbestos exposure for a long period causes asbestosis. They entire the body through inhalation and are deposited in the alveoli. The long exposure of dust can lead to carcinoma of bronchus. (REF. PARK&;S TEXTBOOK OF PREVENTIVE AND SOCIAL MEDICAL 21ST EDITION. PAGE NO - 748)