Environmental (geographic aspects)

Low level of soil molybdenum ;Soil salinity; Thermal; Vulcanization-process in factory; Water pollution by petroleum products

Dietary

Aflatoxins; Asbestos; Bush tea; Fungi (Fusarium, Altemaria spp.); Malze consumption; Nutritional deficiencies of vitamin A, E, and C; Niacin; Zinc

Chronic irritation

Achalasia; Scleotherapy by injection; Reflux esophagitis (Barrett’s esophagus); Lye ingestion

Habit

Alcohol beverage; Smoking

Cultural

Low socioeconomic status; Race

Miscellaneous

Hiatal herniation; Ionizing radiation; Papillomavirus infection; Pharyngoesophageal diverticulum; Plummer-Vinson syndrome; Sprue; Tylosis