Abstract

Question What are the long-term health complications associated with sulfur mustard exposure, and are there differences associated with exposure levels or demographic characteristics? Findings In this cohort study of 64 190 chemical warfare survivors of the Iran-Iraq War from 1980 to 1988 registered in the Veterans and Martyr Affair Foundation database, there were sex differences in the frequencies of eye and skin complications among survivors of sulfur mustard exposure. Lung complications were more apparent in later years following sulfur mustard exposure in survivors who had no initial signs of distress, and these complications were observed more among persons who were not evacuated or hospitalized than among those who were. Meaning Differences in health complications may be due to distinct physiological responses or levels of chemical exposure, and close monitoring even decades after sulfur mustard exposure is required to detect late pulmonary complications. Importance The prevalence and severity of long-term health complications after exposure to sulfur mustard are unknown. Objective To investigate the long-term health outcomes among survivors exposed to sulfur mustard during the Iran-Iraq War. Design, Setting, and Participants In this retrospective cohort study, late-onset health complications of 64 190 Iranian survivors exposed to sulfur mustard during the Iran-Iraq War from 1980 to 1988 were investigated using descriptive statistics. Data involving affected organs and symptom severity were extracted from the Veterans and Martyr Affair Foundation (VMAF) database from 1980 to 2019. Assessments were conducted across 3 groups depending on whether survivors were (1) evacuated and admitted (EA) to a hospital; (2) not evacuated or admitted (NEA) to a hospital; or (3) evacuation or admission status was not documented. Exposures Analysis of chronic symptom severity following exposure to sulfur mustard. Main Outcomes and Measures Mild, moderate, or severe rankings of symptoms in lungs, eyes, and skin of survivors exposed to sulfur mustard using data from the VMAF database. Results Of 64 190 chemical survivors registered in the VMAF database, 60 861 met the inclusion criteria. Of the included survivors, 98.0 were male, and the mean (SD) age was 23.5 (7.7) years. Most survivors (53 675 88.2%) had no symptoms or mild lesions, and 7186 survivors (11.8%) had moderate or severe complications. Moderate to severe lung (6540 10.7%), eye (335 0.6%), or skin (725 1.2%) injuries were documented in the exposed population. The proportion of moderate plus severe late complications in eyes was 3 times as high in male survivors compared with female survivors (0.6% 95% CI, 0.53%-0.65% vs 0.2% 95% CI, 0.09%-0.73%; P < .001), whereas dermal complications were significantly more common in female survivors (3.9% 95% CI, 2.92%-5.11% vs 1.14% 95% CI, 1.06%-1.23%; P < .001). Mild lung lesions were more prevalent in the NEA group than in the EA group (73.9% 95% CI, 73.4%-74.4% vs 11.0% 95% CI, 10.6%-11.3%; P < .001). In the NEA group, 83.2% (n = 23 866) developed lung injuries that were mostly mild or moderate, whereas 77% (n = 24 766) of the EA group did not develop lung injuries (P < .001). Conclusions and Relevance The present study found sex differences in the frequencies of eye and skin complications following sulfur mustard exposure, and lung complications were more prevalent years after sulfur mustard exposure than soon after exposure. Mild lung lesions were observed more frequently among sulfur mustard-exposed survivors who had not been evacuated or hospitalized than among those who had been evacuated or hospitalized. These differences may be due to physiological response or dose of exposure. Close monitoring over an extended period may be required for detection of late pulmonary complications in individuals exposed to sulfur mustard. This cohort study investigates the prevalence by sex, age, and symptom severity of long-term lung, eye, and skin complications among survivors exposed to sulfur mustard between 1980 and 1988 during the Iran-Iraq War.