I believe that considerable damage has been done to those people taking iodized salt but unaware that they were taking it, and that any legislation that would make its use practically compulsory would be most unwise. Just how I can help you in opposing this measure I am not quite clear, but would be very eager to help. I hesitate to suggest your coming to New York simply to discuss the matter because the facts seem adequately stated in Dr. Stokes' letter to Mr. Condon. I believe the American Dermatological Association would pass a resolution opposing the measure, but their next meeting would be in the latter part of April, which may not be in time to be of help. I expect to attend a meeting of the American Academy of Dermatology in Chicago, December 6 to 11. Many other physicians interested in the problem will also attend that meeting and I would suggest that if it was at all possible for you to do so it would be well for you to come to that meeting where it would be discussed with many dermatologists from various parts of the country. Please let me know if this would meet with your convenience. Very sincerely yours, J. GARDNER HOPKINS. AMERICAN ACADEMY OF DERMATOLOGY AND SYPHILOLOGY, Dr. O. P. KIMBALL, Hanna Building, Cleveland, Ohio. February 11, 1948. DEAR DR. KIMBALL: At the last meeting in Chicago on December 8, 1947, the following resolution was passed by the board of directors and subsequently approved at the general meeting of the Academy of Dermatology and Syphilology. "Whereas it is proposed to legislate effective means to provide on a national scale the use of iodized salt as a measure of public health in the prevention of endemic goiter; "Whereas it is recognized that certain diseases of the skin may possibly be precipitated or aggravated by the ingestion of iodine or its salts: Therefore be it "Resolved, That the American Academy of Dermatology and Syphilology go on record as approving such legislation on general principles providing that so-called iodine-free table salt be not excluded from the market but be made available for the use of such sensitive persons." Very truly yours, CLYDE L. CUMMER, M. D., President. CLEVELAND DERMATOLOGICAL SOCIETY, September 25, 1947. It is moved that the Cleveland Dermatological Society approve the pending legislation requiring a maximum of 160 milligrams of iodine per million parts of table salt-equivalent to 10 grams of potassium iodide in 1 year. In approving this legislation, it should also be understood that there will also be on the market other salt containing no iodine for those very rare individuals sensitive to the same. Approved : GEORGE W. BROWKLEY, President. H. G. MISKJRAN, M. D., Secretary pro tem. HENRY FORD HOSPITAL, Detroit 2, Mich., October 22, 1947. DEAR DR. KIMBALL: The meeting of the Detroit Dermatological Society, of which I told you, was held last night, and at this meeting the society passed a resolution favoring the legislation for adding iodine to all table salt, except, of course, the kosher salt. This resolution was not passed unanimously, but was favored by 90 percent of the society. I am enclosing the letters you left with me, which, I feel, had a great deal of influence with the members in their decision. I believe the letter of Dr. Osborne probably was nearly as effective as Dr. Cole's communication, which, however, everyone felt stated the facts in the case. Sincerely yours, FRANK R. MENAGH. MAYO CLINIC, Dr. O. P. KIMBALL, Hanna Building, Cleveland, Ohio. Rochester, Minn., September 17, 1947. DEAR DR. KIMBALL: At the request of my colleague, Dr. Russell Wilder, I am writing you to express my support and that of my colleagues at the Mayo Clinic for pending legislation which will require a content of not more than 160 milligrams of iodine per million parts of table salt, it being understood that such legislation will provide for the sale of other salt labeled to indicate it contains no iodine. My colleagues and I see very few patients who we have reason to believe would be benefited by the use of salt containing no iodine; nevertheless, such salt should be available for the exceptional patient. The importance of a more satisfactory distribution of iodine through inclusion of iodine in table salt is apparent from the effective reduction of the incidence of colloid goiter which followed the original promotion of iodized salt. Very truly yours, PAUL A. O'LEARY, M. D. A LIMITED EXAMINATION OF THE EFFECT OF IODIZED SALT UPON CERTAIN FRUITS AND VEGETABLES Robert H. Cardinell and William F. Robertson, Michigan State College This preliminary work was undertaken to determine, if possible, any harmful effects in the use of iodized salt in the commercial preparation of foods. TYPES OF SALT USED IN THE TESTS Three types of salt were used in the tests. The first was plain NaCl, or table salt, which was in tablet form of 50 grains to each tablet. The second type of salt was "Free Flow" brand free running salt, containing 1 percent magnesium carbonate. The third type was "Free Flow" brand free running iodized salt containing 1 percent magnesium carbonate and 0.01 percent potassium iodide. In the canning of carrots, tomatoes, and beets each No. 2 can contained 50 grains of salt, and at least three cans of each type were prepared for this experiment. METHODS OF PREPARATION Carrots were washed and blanched in steam for about fifteen minutes until the skins slipped easily. After they were skinned and trimmed, they were sliced and packed into containers. A total of nine cans was packed. Three cans each were packed with 50 grams of plain NaCl, free flowing salt, and iodized salt, respectively. Hot water was added to fill the cans and they were put in a steam exhaust prior to closing. The closed cans were processed at 240° F. for 30 minutes, then cooled under tap water. Storage was at room temperature, or about 72° F. Beets were canned in essentially the same manner as the carrots. Tomatoes were steam-peeled, cored, and packed into No. 2 cans until they were covered with their own juice. Again the three types of salt were used in three-can lots as before. Apples were trimmed and peeled and immediately placed in a 21⁄2 percent salt solution, made from iodized salt. Sliced, cored, and trimmed again, they were replaced in the salt solution. Then they were placed in a fresh 21⁄2 percent solution of iodized salt and allowed to stand overnight at room temperature. The following day these apples were removed from the salt solution, steam blanched for 8 minutes, and packed in No. 2 cans which were then filled with hot water, steam exhausted 8 minutes, closed, and processed in boiling water for 10 minutes, cooled under tap water and stored at room temperature. The quantity of salt remaining in these apples is unknown. Sauerkraut was made in two batches. One batch, for control, was made with plain NaCl and the other with iodized salt. Each batch contained 10,430 grams of fresh cabbage shredded into crocks with 2% percent, or 260 grams, of salt evenly spread throughout. The mixture of cabbage and salt was then tamped down until a liberal amount of juice was liberated. The crocks were then covered with a layer of cheesecloth below a weighted cover fitting the interior. The crocks were stored in a room with a temperature ranging about 65° F. Both batches were made and stored under identical conditions. RESULTS The following tests were made on each of the products: Free iodine. Each product was tested for the presence of free iodine that may have been liberated due to some chemical reaction having taken place during the processing of the product or subsequent storage. A 10-percent starch solution in the presence of free iodine gives a distinct dark blue or purple color in solution. The color is more permanent when the solution is acid than when alkaline. Liberated iodine. When a negative test was obtained by testing the products for free iodine with a startch solution, an effort was made to liberate the iodine from its combined form and then test again. This was done with a normal solution of 2, 6 dichloro-phenol-indophenol dye (blue color). Smell of iodine. Each product was smelled for the presence of iodine by several people, both in the cold condition and after heating. Taste of iodine. Each product was tasted by a competent panel of people, both when the product was cold and after heating. Discoloration of the product. Each product was examined and compared with noniodized products by several individuals to determine if they could detect any discoloration or spots that might be attributed to the presence of iodine. The results of these tests on the canned carrots, tomatoes, beets, apples and sauerkraut were all negative. In each case the clear juice from the can was tested as well as macerated solid material and juice together. This latter mixture was then filtered and the resulting juice alone was used. Interesting results occurred in the two batches of sauerkraut regarding the percent of lactic acid formation. As can be seen in the following table, there is a decided difference in the percent lactic acid produced by the two batches of sauerkraut. Perhaps the presence of iodized salt tends to speed up the production of acid. This may be accomplished as either a catalytic action upon the part of the iodine or else the iodine in the salt may enrich the media in such a manner that the rate of growth of the lactic acid producing bacteria is speeded up. This greater lactic acid production due to iodized salt might bear further invesigation by the sauerkraut industry. Average percent lactic acid in sauerkraut (3 titrations each time) AMOUNT OF SALT AND POTASSIUM IODIDE IN A NO. 2 CAN To determine a reason for continued negative results when testing for the presence of iodine in all products canned, the amount of salt and the amount of potassium iodide in the salt were determined mathematically. These calculations are listed: Known facts: 1 gram equals 15.432 grains. 1 grain equals 0.65 grams. KI in salt equals 0.01 percent. I ounce equals 28.35 grams. No. 2 can equals 20.55 ounces (avoirdupois) of water when sealed at 68° F. Calculations: Weight of 50 grains of salt is 0.65×50 equals 3.250 grams. A No. 2 can full contains 382.59 grams. Percent salt in a No. 2 can-3.25/382.59 equals 0.8495 percent. Amount of KI in 50 grains of salt-3.250 X .001 equals .0003250 grams KI. Percent potassium iodide (KI) in a No. 2 can-0.000325/382.59 equals 0.00008495 percent. This 0.00008495 percent KI weighs 0.0003250 grams in a No. 2 can. Of this 0.00008495 percent KI in each can approximately two-thirds is iodine or 0.000217 grams. These percentages and weights determined are those that would be found if the No. 2 can were filled with plain water. The can filled with various types of products will alter these percentages or weights slightly. AMOUNT OF SALT AND POTASSIUM IODIDE IN KRAUT Listed below are the calculations to determine the amount of salt and potassium iodide (KI) in sauerkraut: Known facts: Amount of KI in the salt equals 0.01 percent. Amount of cabbage equals 10,430 grams. Amount of salt added to the cabbage equals 260 grams. Weight of the total salt and cabbage mixed equals 10,690 grams. Calculations: Percent salt in the sauerkraut equals 2.5 percent. Amount KI in this amount of salt equals 260×0.0001 equals 0.0260 grams. Percent KI in the sauerkraut-0.0260/10,690 equals 0.000243 percent KI. Amount of KI present in the sauerkraut-10,690×0.00000243 equals 0.0260 grams. Table showing percent and weights of salt and KI in various products Inasmuch as entirely negative results were obtained when testing for the presence of iodine, it seemed desirable to determine what percent of iodine was necessary in a product to give a positive test. As has been shown above, products made with iodized salt contain a very minute quantity of iodine. The first test of an experimental nature for iodine was made using tincture of iodine which contained 20 percent iodine crystals dissolved in 80 percent alcohol. Diluting this tincture of iodine to various percentages and in the presence of a 10 percent starch solution, the following results were obtained: 0.0100 percent tincture of iodine solution plus starch solution equals a positive test. 0.0075 percent tincture of iodine solution plus starch solution equals a positive test. This test shows that free iodine, even as low a percent as 0.0075, will give a positive iodine test in the presence of starch solution. A further test was conducted to see exactly how much iodized salt needed to be dissolved in water before a positive test could be obtained for the presence of the liberated iodine. Below is a statement showing increasing amount of iodized salt saturated in water, and with enough 2,6 dichloro-phenol-indophenol dye added to liberate all the iodine, until a positive test for iodine was obtained. The media was kept acid with dilute H2SO4. Distilled water was used in all cases. 25 milliliter water plus 200 grains iodized salt plus 10 milliliter dye plus acid plus starch=negative. 30 milliliter water plus 250 grains iodized salt plus 12 milliliter dye plus acid plus starch=negative. 30 milliliter water plus 300 grains iodized salt plus 12 milliliter dye plus acid plus starch-positive. The last test conducted was to determine the lowest point at which a positive test would occur when testing for liberated iodine using potassium iodide crystals. This procedure and the results follow: 0.50 grams KI plus 5 milliliter water plus 1 milliliter dye plus starch solution gives positive result. 0.25 grams KI plus 5 milliliter water plus 1 milliliter dye plus starch solution gives positive result. 0.125 grams KI plus 5 milliliter water plus 1 milliliter rye plus starch solution gives negative result. As shown above, it takes over 0.125 grams or 1.929 grains of pure potassium iodide crystals before a positive test may be obtained. In a No. 2 can there are only 0.000325 grams of KI present and it is no wonder that this amount would not give a positive test when at least 0.125 grams is needed for a positive test for liberated iodine. CONCLUSIONS From this limited work the indications are that the small amount of iodine in iodized salt that would normally be used in canning the fruit and vegetables used in this experiment and in the making of sauerkraut imparts no detectable ill effect. In fact, it would take 300 grains of iodized salt in a saturated solution to give a positive test for iodine, and, even with this positive test, iodine could be neither tasted nor smelled in this solution. |