Improved salt iodation methods for small-scale salt producers in low-resource settings in Tanzania

• Main Authors: Assey Vincent D, Tylleskär Thorkild, Momburi Philip B, Maganga Michael, Mlingi Nicholaus V, Reilly Marie, Greiner Ted, Peterson Stefan
• Format: Article
• Language: English
• Published: BMC 2009-06-01
• Series: BMC Public Health
• Online Access: http://www.biomedcentral.com/1471-2458/9/187

<p>Abstract</p> <p>Background</p> <p>Universal salt iodation will prevent iodine deficiency disorders (IDD). Globally, salt-iodation technologies mostly target large and medium-scale salt-producers. Since most producers in low-income countries are small-scale, we examined and improved the performance of hand and knapsack-sprayers used locally in Tanzania.</p> <p>Methods</p> <p>We studied three salt facilities on the Bagamoyo coast, investigating procedures for preparing potassium-iodate solution, salt spraying and mixing. Different concentrations of solution were prepared and tested using different iodation methods, with the aim of attaining correct and homogeneous iodine levels under real-life conditions. Levels achieved by manual mixing were compared to those achieved by machine mixing.</p> <p>Results</p> <p>The overall median iodation level in samples of salt iodated using previously existing methods was 10.6 ppm (range 1.1 – 110.0 ppm), with much higher levels in the top than the bottom layers of the salt bags, p < 0.0001. Experimentation using knapsack-sprayers and manual mixing led to the reliable achievement of levels (60.9 ppm ± 7.4) that fell within the recommended range of 40 – 80 ppm. The improved methods yielded homogenous iodine concentrations in all layers of salt-bags (p = 0.58) with 96% of the samples (n = 45) falling within 40 – 80 ppm compared to only 9% (n = 45) before the experiment and training (p < 0.0001). For knapsack-spraying, a machine mixer improved the iodine levels and homogeneity slightly compared to manual mixing (p = 0.05).</p> <p>Conclusion</p> <p>Supervised, standardized salt iodation procedures adapted to local circumstances can yield homogeneous iodine levels within the required range, overcoming a major obstacle to universal salt iodation.</p>