Table salt was iodinated with potassium iodide or iodate by spray mixing (Diosady, Alberti, Mannar, & Stone, 1997). A total of 10 ml solution at a concentration of 3 g KI l1 or 3.9 g KIO3 l1, respectively, was sprayed per 1 kg table salt while it was constantly mixed in a homogenizer (Homogenizer 2094, Fos Tecator, Sweden). The iodised salt was freeze-dried.