1, 1924, iodised salt was sold commercially in Michigan. By the fall of 1924, Morton Salt Company began distributing iodised salt nationally. A 2017 study found that the introduction of iodized salt in 1924 raised the IQ for the one-quarter of the population most deficient in iodine. These findings "can explain roughly one decade's worth of the upward trend in IQ in the United States (the Flynn effect)". The study also found "a large increase in thyroid-related deaths following the countrywide adoption of iodized salt, which affected mostly older individuals in localities with high prevalence of iodine deficiency". A 2013 study found a gradual increase in average intelligence of 1 standard deviation, 15 points in iodine-deficient areas and 3.5 points nationally after the introduction of iodized salt. A 2018 paper found that the nationwide distribution of iodine-fortified salt increased incomes by 11%, labor force participation by 0.68 percentage points and full-time work by 0.9 percentage points. According to the study, "These impacts were largely driven by changes in the economic outcomes of young women. In later adulthood, both men and women had higher family incomes due to iodization." No-additive salts for canning and pickling In contrast to table salt, which often contains iodide as well as anti-caking ingredients, special canning and pickling salt is made for producing the brine to be used in pickling vegetables and other foodstuffs. Contrary to popular belief, however, iodized salt affects neither color, taste, nor consistency of pickles. Fortification of salt with other elements Double-fortified salt (DFS) Salt can also be double-fortified with iron and iodine. The iron is microencapsulated with stearin to prevent it from reacting with the iodine in the salt. By providing iron in addition to iodine in the convenient delivery vehicle of salt, it could serve as a sustainable approach to combating both iodine and iron deficiency disorders in areas where both deficiencies are prevalent. Adding iron to iodized salt is complicated by several chemical, technical, and organoleptic issues. Since a viable DFS premix became available for scale-up in 2001, a body of scientific literature has been emerging to support the DFS initiative including studies conducted in Ghana, India, Côte d'Ivoire, Kenya and Morocco. Fluoridated salt In some countries, table salt is treated with potassium fluoride to enhance dental health. Diethylcarbamazine In India and China, diethylcarbamazine has been added to salt to combat lymphatic filariasis. See also Basil Hetzel Enriched flour