The ancient Greeks and others used iodine-rich seaweed to combat goiters, but it was not until 1821 that French nutritional chemist Jean Baptiste Boussingault discovered salt iodine-rich salts could be used to treat goiter, though he did not understand its preventive role. At the same time, Swiss physican J.F. Coindet successfully employed iodine therapy for goiter. Thirty years later, another French scientist, A. Chatin hypothesized that iodine deficiency caused goiters, but an expert group of his country's Academy of Scientists rejected the claim and killed the idea for another half century.
In the years 1907-1909, Dr. David Marine, a young doctor in Cleveland, OH, USA, began working explicitly on using iodine-fortified salt to prevent goiter. An early Marine effort to conduct a large-scale trial of iodized salt in the Cleveland public schools was vetoed by another doctor who served as chairman of the school board. That delayed the determined Dr. Marine until 1916 when he teamed with O.P. Kimball to convince the Akron, OH school board to conduct the experiment on elementary school girls (who had twice the incidence of goiter). The experiment was completely successful. The lead shifted to Michigan where, due to the strong leadership of Dr. David Murray Cowie of the University of Michigan and the Michigan State Medical Society, a symposium highlighted the work in Akron and similar work in Switzerland. Dr. Cowie contacted Diamond Crystal Salt Company (now merged into Cargill Salt Company) and Morton Salt Company, leading to discussions with the salt producers association and by 1924 iodized salt was commonly available in the U.S. In less than a decade, 90+% of the salt consumed in the U.S. "goiter belt" was iodized. Goiter incidence plummeted, as an example, in Detroit from 9.7% to 1.4% in the first six years of using iodized salt.
David Marine later worked on salt iodization for the World Health Organization and many areas have replicated the benefits of iodized salt.
For further information:
Iodized Salt (Salt Institute)
"David Marine and the Problem of Goiter" by Kenneth J. Carpenter, Journal of Nutrition, 135;675-680 (2005)
"'When it Rains it Pours': Endemic Goiter, Iodized Salt, and David Murray Cowie, MD" by Howard Markel, MD, American Journal of Public Health 77;2:219-229 (1987)
"The History of Food Fortification in the United States: Its Relevance for Current Fortification Efforts in Developing Countries" by David Bishai and Ritu Nalubola, in Economic Development and Cultural Change (Chicago, University of Chicago Press, 2002)
