Geochemistry of iodine-rich groundwater in the Taiyuan Basin of central Shanxi Province, North China

► Iodine concentration, distribution and origin in the groundwater of Taiyuan Basin. ► Over 75% of samples exceed National Drinking Water Standard for Iodine (150 μg/L). ► Geology, topography and hydrogeochemistry are the main causes of I enrichment. ► Main sources of groundwater iodine are marine, lacustrine and fluvial sediments.