Towards USI: A Salt Industry Perspective

Humanity as well as economics demands that we achieve our global public health goal of ensuring adequate iodine nutrition through universal salt iodization (USI). To avoid condemning millions of newborn infants each year to lives of men tal de?ciency requires a preventive strategy that is as simple technologically as it is affordable. In fact, we cannot afford not to ful?ll the priority commitment of the 1990 World Summit for Children to virtually eliminate iodine de?ciency disorders (IDD) through out the world.

Many health challenges are manifest due to varia tions in genetics, prosperity, geography or other factors largely beyond our control. These health con ditions vary from individual to individual. They are medical problems.

Iodine de?ciency is different. Iodine is an essential nutrient. The body does not produce iodine; it must be ingested. Every human needs supplemental iodine. Eliminating iodine de?ciency is a classic public health opportunity. Where diets are iodine de?cient, provid ing supplemental iodine can be achieved most effectively on a population basis.

Fortification is the answer

Fortifying foods has been an efficient mechanism to combat nutritional de?ciencies. We consume for ti?ed foods every day: Vitamin D in milk; thiamin, niacin, ribo?avin, iron and folic acid in cereals and bread; calcium in orange juice; Vitamin A in mar garine. The list of forti?ed foods is long. We have been fortifying salt with iodine for eighty years. It has been the huge success in iodizing salt that led to the widespread use of food forti?cation today.

But why iodize salt? Surely there are other candidate foods. Cooking oils and drinking water have been iodized successfully and may be a preferred solution in certain locales. Salt is a superior food for iodiza tion because it is also the least expensive option for fortifying a food. Iodide and iodate compounds are inexpensive. The process requires minimal capital investment and imposes low operating expense. Neither oil nor water can be iodized so cheaply. The preferred choice of salt, however, is for more reasons than the fact that it is the least expensive delivery mechanism.

Humans require iodine within a certain "safe and adequate" intake range, as is the case for virtually every nutrient. Thus, the choice of which food should be iodized assumes even greater signi?cance. If food manufacturers were to indiscriminately fortify their products with all manner of "good" nutrients like iodine, ensuring micronutrient adequacy while avoiding excess consumption would be complicated. With salt, that problem disappears.

Every day every person everywhere in the world eats salt. All societies except a few remote and primi tive ones have access to salt. Once traded ounce for ounce for gold, salt production using modern tech nology and transportation has made salt abundant and inexpensive.

Humans consume salt in a predictable 6-12 grams/day range. Except in a few societies like north ern China and Japan, salt intakes are relatively predictable with 80-90% of the population clustered together. Medical studies have con?rmed the stability of salt intakes within populations and over time. They are unchanged over the century since we dis covered how to measure urinary sodium accurately.

Nor should this be at all surprising. Every species of livestock and poultry consumes salt in predictable amounts which is the basis for common use of salt as a carrier for trace minerals and medications to ensure animals' health. Not insigni?cantly, iodine is among the most commonly used trace element to fortify animal salt.

Since intake levels are predictable, metering nutri ent forti?cants in salt is a simple mathematical exercise. Besides iodine, food salt is often forti?ed with ?uoride in areas where drinking water is not ?uoridated and with iron to combat anemia. Animal salt is forti?ed with still other micronutrients: cobalt, copper, manganese, molybdenum, selenium, iron, zinc, magnesium and sulfur. Salt is also used as a carrier to meter medications to livestock and poultry.

Unsurprisingly, public health agencies are in total consensus that iodizing salt ensures an achievable, affordable and, most importantly, predictable intake of iodine.

Iodizing salt is a simple technology

Adding iodine to salt is not "rocket science." To dry salt is added either a dry mix or liquid drip or spray of potassium iodate or potassium iodide, with the addi tion of stabilizing additives, where needed. Obtaining the iodide or iodate is likely to be more difficult for salt manufacturers than actually applying it to the salt. Often, as well, it is a greater challenge to change prod uct packaging to protect the iodate or iodide from humidity and other environmental degradation than to actually produce iodized salt. Any salt producer capable of delivering clean salt to consumers has the technical capability to iodize that salt.

Around the world, the majority of salt is produced in huge salt re?neries or scienti?cally managed solar saltworks. But most salt makers are very small busi nesses; though numerous, they collectively produce only a minority of the 210 million tons of salt con sumed each year for a myriad of purposes. Globally, the vast majority of producers use primitive tech nologies. These businesses don't prepare business plans or use spreadsheets to manage their operations. Often they operate at a scale sufficient to support a single family. These small salt makers are relatively unsophisticated; many have never heard of iodine or its role in preventing brain-damaged children.

That salt can be produced using technologies avail able for millennia imposes special challenges to achieving USI. Were salt an expensive man-made chemical rather than an inexpensive natural mineral, the relatively few, and highly sophisticated, producers would be easy to identify and educate (or compel) to iodize salt. That is not the world in which we live. Salt is not expensive. Salt producers need no sophis ticated understanding of geology, chemistry or meteorology. Barriers to entry into these subsistent operations of salt production are low. If the climate is conducive to salt making, anyone with a beach or frontage of a saline lake can make salt with minimal capital outlay. This type of producer is common and just as commonly unable to make high quality salt, unable to make signi?cant quantities and usually unable (or uninterested) to market their product in protective packaging. But they do put salt in com merce, competing with the cleaner, iodized and packaged salt. For these small companies, cleaning and drying this crude salt and packaging it into small plastic bags is often more challenging than actually adding volatized potassium iodate to the salt.

As a national salt industry modernizes, accompa nied by effective government regulations for food safety and increased consumer demand for purer iodized salt, these smaller, less sophisticated opera tions either modernize or are closed. Thus modernization is intertwined in the very process of implementing and sustaining USI. Pursuing this modernization process depends on all three "part ners": the salt companies themselves, but also government regulators and the consuming public.

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