Incidence of cancer in Iranian sulfur mustard exposed veterans: a long-term follow-up cohort study

Introduction: It is estimated that during the Iraq–Iran war of the 1980s, over 100,000 Iranians (military or civilian) were exposed to sulfur mustard (SM), and a considerable proportion of them are still suffering with long-term consequences of exposure. The aim of the present article is to address carcinogenesis of SM following these acute exposures. Methods: Using a cohort study, we estimated and compared the incidence rates of malignant disorders in 7,570 veterans exposed to SM and 7,595 unexposed comrades in a 25-year follow-up period. We also determined the hazard ratio of cancer occurrence for SM exposure during the follow-up period. Results: Cancer incidence was significantly increased with exposure to SM. The incidence rate ratio of cancer for SM exposure was 1.81 (95 % CI 1.27–2.56), and the age-adjusted incidence rate ratio was 1.64 (95 % CI 1.15–2.34). The hazard ratio of cancer was 2.02 (95 % CI 1.41–2.88). Conclusion: Present study suggests carcinogenesis of SM following acute exposure during war. With respect to this finding, it is reasonable to improve care programs such as routine screening schemes for exposed veterans.