Probabilistic Health Risk Assessment of Iodine Exposure in Bangladesh

In this study, the concentrations of iodine in household salt samples (n = 690) were determined by following the iodometric titration method, and the health risks of Bangladeshi people were assessed based on the semi-probabilistic approach and the US Environmental Protection Agency (USEPA) deterministic model. After adjusting 20% of cooking losses, the iodine concentration (mean, range) in salt samples of Phultala, Dighalia, Terokhada, Rupsha, Batiaghata, Dumuria, Paikgacha, Koyra, Dacope, and KCC was (29.68 ± 8.67, 14.39-48.26), (31.05 ± 6.68, 15.24-43.18), (26.94 ± 5.57, 16.09-45.72), (24.33 ± 5.61, 12.70-37.26), (26.69 ± 6.73, 10.16-44.87), (27.20 ± 8.44, 9.31-53.34), (27.71 ± 8.09, 8.46-47.42), (28.39 ± 7.80, 11.01-46.57), (28.20 ± 7.97, 3.38-49.10), and (29.21 ± 6.62, 18.62-40.64) mg/kg, respectively. The iodine contents in 97.25% of samples were within the standard fortification level of Bangladesh (15-50 mg/kg), while 2.61% of samples were below this limit. The semi-probabilistic risk assessment studies showed that 80.14% of samples at a low ingestion rate could provide optimal nutrition (150-299 μg/day) to the whole population. Contrarily, at medium, moderate-high, and high consumption rates 34.93%, 65.22%, and 85.94% of samples, respectively, belonged to above the requirements to excessive exposure categories (300-1100 μg/day), which might cause iodine-induced diseases. The target hazard quotient (THQ) values for the adults in most of the samples were within the threshold risk limit (THQ < 1.0), whereas THQ values in 6.82% to 85.97% of samples for the children at low to high ingestion rates, respectively exceeded this limit, which revealed that the adults were almost safe, but the children might face non-carcinogenic health effects. Therefore, regular monitoring of iodine concentration in iodized salts should be done to prevent iodine deficiency or iodine-induced disorders.