Comments
Information relating to occupational causes of esophageal cancer is limited. It is not known what proportion of esophageal cancer today is linked to workplace exposures. Some studies suggest associations with occupational exposures to perchloroethylene, mustard gas, silica dust, metal dust, asbestos, combustion products, sulfuric acid, carbon black, and ionizing radiation. [Ward, p. 195] Many of these studies have inadequate adjustment for the main confounders, smoking and alcohol use. Based on heavier exposure levels that existed in the past, two groups that showed higher risks for cancer of the esophagus were workers who vulcanized rubber and those who assembled automobiles. [Adami, p. 152-3] There is suggestive evidence that occupational exposure to soots and tetrachloroethylene cause esophageal cancer. [Siemiatycki, p. 334] Studies of radiologists, underground miners, and nuclear workers have found negative associations. "Meaningful associations" were found for Japanese A-bomb survivors and patients with spondylitis treated with medical radiation. [Boice, p. 261]