ABSTRACT
Epidemiological studies have demonstrated an increased risk of upper respiratory tract cancer, primarily nasal tumors, in several occupations, such as nickel refinery workers and workers engaged in the manufacture of wooden furniture or leather boots and shoes (1). In addition, nasopharyngeal cancer in southeastern China and Hong Kong has been associated with the consumption of salted fish, which ap peared to contain high concentrations of volatile nitrosamines capable of inducing nasal tumors in experimental animals (2). Tobacco smoking and alcohol drinking are important causes of laryngeal cancer in humans (3,4). There are some indica tions for an increased risk of laryngeal cancer among workers who manufactured furniture, mustard gas, isopropyl alcohol, or sulfuric acid (5).
