Serum Concentration of Thyroid Hormones Long-Term after Sulfur Mustard Exposure

Despite several reports on the clinical manifestations of sulfur mustard (SM) intoxication, there is no study on serum concentrations of thyroid hormones long-term after SM exposure. In this study, the changes in thyroid functioning parameters 20 yr after SM exposure were evaluated.

This study is a part of a larger historical cohort study conducted in 2007 following 20 years of the exposure to SM, called Sardasht-Iran cohort study (SICS). We (SICS) comprised an SM-exposed group from Sardasht City, West Azerbaijan Province, Iran (n=169 as hospitalized group and n=203 as non-hospitalized exposed group); and control participants were selected from Rabat, a town near Sardasht (n=126). Peripheral blood samples were taken in fasting state and then the sera were separated. T4, T3, TSH, antithyroglobulin (anti-Tg), and antithyroid peroxidase (anti-TPO) concentrations in the sera were measured by the ELISA method.

The mean of T3 concentration was significantly higher in the exposed than control group (0.88 ± 0.26 nmol/L vs 0.8 ± 0.25 nmol/L, P<0.001). The levels of TSH, T4, and T3up were not significantly different between the exposed and control groups. Thyroglobulin level was significantly higher in the exposed non-hospitalized group (56.07 ± 140.22 μg/L vs 17.66 ± 41.49 μg/L, P=0.004), but the level of anti-Tg and anti-TPO showed no significant differences between the two groups.

More studies are needed on the alterations in thyroid hormones, their gene expressions, and mechanisms involved in SM exposure to clarify the causes of these alterations.