Childhood physical abnormalities following paternal exposure to sulfur mustard gas in Iran: a case-control study

BACKGROUND Mustard gas, a known chemical weapon, was used during the Iran-Iraq war of 1980-1988. We aimed to determine if exposure to mustard gas among men was significantly associated with abnormalities and disorders among progenies. METHODS Using a case-control design, we identified all progenies of Sardasht men (exposed group, n = 498), who were born at least nine months after the exposure, compared to age-matched controls in Rabat, a nearby city (non-exposed group, n = 689). We conducted a thorough medical history, physical examination, and appropriate paraclinical studies to detect any physical abnormality and/or disorder. Given the presence of correlated data, we applied Generalized Estimating Equation (GEE) multivariable models to determine associations. RESULTS The overall frequency of detected physical abnormalities and disorders was significantly higher in the exposed group (19% vs. 11%, Odds Ratio [OR] 1.93, 95% Confidence Interval [CI], 1.37-2.72, P = 0.0002). This was consistent across sexes. Congenital anomalies (OR 3.54, 95% CI, 1.58-7.93, P = 0.002) and asthma (OR, 3.12, 95% CI, 1.43-6.80, P = 0.004) were most commonly associated with exposure. No single abnormality was associated with paternal exposure to mustard gas. CONCLUSION Our study demonstrates a generational effect of exposure to mustard gas. The lasting effects of mustard gas exposure in parents effects fertility and may impact child health and development in the long-term.