Occurrence of Perchlorate in Various Water Sources in South India

Iodine is necessary for synthesis of thyroxine within the thyroid gland. Iodine deficiency leads to hypothyroidism and goitre. Sometimes, even when sufficient iodine is present in food and water, goitre occurs. This could be due to some other competing ions in the ingested food and water, which prevent incorporation of iodine into the thyroid gland. Perchlorate is one such ion and has thirty times more affinity to thyroid, than iodine. Perchlorate is discharged into the environment by fireworks and explosives industries. Hence, the perchlorate levels would be higher in and around such industries. This study was done to determine the perchlorate exposure to humans in their habitat. In this study, perchlorate levels in different water sources in localities with and without such industries were ascertained. The estimation was done by two methods (i) Thionine ion pair spectrophotometry and (ii) ion exchange chromatography with conductivity detection methods. In the results, perchlorate level was significantly high in different water sources of industrialized areas, when compared to non-industrial areas. These high levels could be the explanation for the high prevalence of goitre in areas with sufficient iodine availability.