Iodophor: Tamed Iodine: The Status of Iodine in Tasmania

By Paul A.C. Richards

This book is a follow up to Goitre Monitor: The History of Iodine Deficiency in Tasmania, published in 2006. Since that time climate change has played a major role in the delivery and availability of iodine to land masses, along with the role of iodophors and the mandatory fortification of bread with iodised salt in Australia and New Zealand over the past 15 years. Several academic colleagues have been invited to discuss the status of iodine from the UK, NZ and Australian perspective in individual chapters, as well as a contribution to the final chapter which discusses 'What the Future Holds' for the delivery and availability of iodine to sustain sufficiency and avoid deficiency of iodine in a changing world.

• Language: English
• Publisher: Gatekeeper Press
• Release date: Nov 9, 2020
• ISBN: 9781662901126

Book preview

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Chapter 1

A definitive history of iodine deficiency in Tasmania

Recommendation of iodised salt in diet to combat goitre in 1833 - Marine and Kimball - prophylactic measures introduced to combat endemic goitre using iodine – nutritional surveys in Tasmania - medical geology.

The history of iodine, its discovery, goitre, treatment and thyroidectomy were adequately covered in Goitre Monitor: The History of Iodine Deficiency in Tasmania.

History of iodine - ancient Chinese; burnt sponge remedy goitre - Bernard Courtois (1777-1838); iodine discovery – William Prout (1785-1850); iodine treatment of goitre recommended 1821; Graves 1835; describes exophthalmic goitre – Rehn; first total Thyroidectomy performed 1880 - Kocher; total Thyroidectomy & first report of Hypothyroidism - Jean Baptiste Boussingault (1802-1887).

However, we will revisit the recommendation of the use of iodised salt and those prophylactic measures practiced in Tasmania in the 19th and 20th centuries.

Recommendation of iodised salt in diet to combat goitre in 1833 Jean Baptiste Boussingault (1802-1887).

Although credit for the introduction of iodised salt is usually given to workers early in the 20th century, actually its use was recommended for the prevention of goitre in 1833 by Jean Baptiste Boussingault (1802–1887), a French mining engineer and agricultural chemist (Boussingault, 1831 and 1833). Influenced by his observations in the Andean highlands of South America, Boussingault made the first recommendation for the general use of iodised salt in goitrous areas after observing the absence of goitre in the lowland localities in Colombia. There, the inhabitants preferred a natural salt obtained from iodine-rich waters in an abandoned mine, which on analysis contained appreciable quantities of iodine. The authorities failed to implement his recommendations.

On his return to France, Boussingault succeeded in introducing iodised salt for goitre prevention in badly affected districts. This campaign began to spread throughout Europe, but unfavourable reactions of iodism were frequent due to over-enthusiastic use and overdose in therapy, as had been observed by Coindet. There was also a mid-century emphasis on the dangers of long-term administration of even minute quantities of iodine (Boussingault, 1831). Consequently, iodide prophylaxis was again discredited and abandoned.

Several cases of the efficacy of goitre reduction with iodine were reported in the Lancet in the late 1820s. P.F. Bellamy, a surgeon from Lyme Regis reported (1828/9):

Iodine, it is true, cannot be termed a new medicine; but still doubts of its efficacy, and prejudices against its employment, I believe, are yet existing. I have seen it employed most beneficially in chronic glandular enlargements; and among the number of cases which I have observed, the following, which came under my own immediate treatment, not only proves this statement, but may, perhaps, excite some degree of interest, and induce some one or more of my professional brethren to make further observation, before they declare it altogether inefficacious, or deem it of little service.

So it would only be assumed that the well informed medical practitioner having these articles at his disposal would have had the capacity to treat such cases in colonial Van Diemen’s Land at the time.

However, in 1911 it was not recognised or fully understood what was causing goitre in the Tasmanian population. Dr. Purdy, Chief Health Officer for Tasmania, gave the results in a paper on an inquiry into the ‘Incidence and Cause of Goitre in Tasmania’ in the pathology section at the Sydney Medical Congress.

The Sun reported:

GOITRE IN TASMANIA CAUSED BY GLACIER WATER.

‘The Incidence and Cause of Goitre In Tasmania’ was the subject of an interesting paper read before the Medical Congress to day by Dr J.S. Purdy.

The doctor stated that he was inclined to think that the Tasmanian evidence showed that goitre was prevalent where the people either drink glacial water or live on flats through which glacier water drains and forms part of the subsoil water. Dr Purdy stated that the active agent in goitre may be destroyed by heat, as water is rendered harmless by boiling.²⁴

The Daily Post in Hobart a week later expanded on the matter:

The Inquiry followed up that undertaken by Dr Colquhoun, of New Zealand. Dr Purdy summed up his investigations with the statement:- I am inclined to think that the Tasmanian evidence, which shows that goitre is prevalent where the people either drink glacier water or live on flats through which glacier water drains, and which must form part of the subsoil water, points to the enlargement of the thyroid being probably due either to some organisms which flourishes in such districts or to some property of Bachwaters. As D. Colquhoun pointed out, ‘Water has been universally suspected, and apparently with reason, the chief factor in producing goitre. Whatever the active agent in goitre may be its activity is destroyed by heat, as water is rendered harmless by boiling. Although no living microorganism has been isolated, the probability is that such is the existing cause of the disease, and possibly it may be found to be associated with some condition dependent on the existence of such an organism either in the soil itself or in the water from neighboring high altitudes.²⁵

Here we still have the supposition that it was something in the water or soil which caused goitre not the lack of something.

Treatment of Derbyshire neck, goitre or bronchocele during the 19th century was primarily associated with the oral administration of iodide of potassium and the application of an ointment applied liberally to the neck or tincture of iodine painted onto the same area. Other treatments included spongia, or roasted spongia and belladonna for cases of exophthalmic goitre (Family Physician, 1882).

Recognition that the use of iodised salt in goitrous areas was the most convenient means for supplying dietary iodine to those in need of it was due almost entirely to the work of Marine and Kimball.

Marine & Kimball - prophylactic measures introduced to combat endemic goitre using iodine.

In 1917, Marine and Kimball initiated the first large-scale programme to prevent endemic goitre by means of iodide. Goitre incidence fell abruptly in the group of schoolgirls in Akron, Ohio who were given sodium iodide regularly, compared with those who did not participate in the study (Marine et al., 1917 and 1920). The study unequivocally demonstrated the preventive and therapeutic effectiveness of small doses of iodine. Opponents of the programme stopped it as an invasion of personal rights (Kohn, 1975). However, the success of this experiment led to its repetition in Switzerland, where the use of an organic iodine preparation greatly reduced the incidence of goitre among school children and stimulated the reintroduction of iodised salt in Europe.

Discovery and Synthesis of Thyroxine

Studies on the chemistry of the thyroid gland prompted the extensive biochemical investigations that led to Edwin Calvin Kendall’s (1886–1972) isolation of crystalline thyroxine in 1914 (Kendall, 1915). Believing it to be a derivative of oxyindole, he named it thyroxyindole. Too bulky a word for every day usage, he shortened it to ‘thyroxin’. Since it was a basic substance, in order to conform with the accepted nomenclature of amino acids, it should be spelled ‘thyroxine’. The correct empirical formula of thyroxine (3,5,3',5'-tetraiodothyronine) was determined by Harington (1926).

In summary, the ancient Chinese recognised goitre and the therapeutic effects of burnt sponge and seaweed in reducing its size or causing its disappearance. The modern use of iodine in the prevention of goitre dates from 1830, when it was proposed that goitre is an iodine deficiency disease. But unfavourable symptoms were frequent, owing to overdose of iodine. Iodine’s presence in organic combination as a normal constituent of the thyroid was established in 1896 and revived its use in treatment and prevention of goitre.

This history of the discovery and early uses of iodine mixes ancient practices, secret recipes, accidental scientific discovery professional rivalry, and the use and misuse of medical discovery against a backdrop of the impact of warfare in the development of science. Careful scientific work eventually led to identification, analysis and synthesis of the element.

Early iodine prophylaxis practised in Tasmania

Iodine was well recognised as a treatment for goitre in Tasmania, and chemists from both traditional and homeopathic persuasions prepared and dispensed iodine solutions, tinctures and ointments to the public as a measure to reduce or dissolve goitres, which were prevalent in several districts of Tasmania. The only other recommendations were the addition of iodised salt to the diet, and in the second half of the 20th century, government controlled prophylactic measures, which included the potassium iodide tablet programmes 1950-1966, the addition of iodate to bread improver 1966-73, fortuitous presence of iodophor residues in milk – which saw the removal of the iodate from bread – and more recently, with a downturn of iodophor use in the dairy industry, iodised salt in bread under a programme of memoranda of understanding with bakeries in Tasmania. It is presumed that about 80% compliance has been achieved since 2002.

From this mandatory prophylactic programme mandatory fortification of bread with iodised salt was universally legislated and accepted in Australia and New Zealand in 2009, stabilising the iodine levels to a more acceptable level reaching about 130µg/L in the Tasmanian population in 2016.

Lugol’s Solution

Lugol’s Iodine (also called ‘Lugol’s solution’) was first developed by the French physician, Jean Lugol, in 1829. It is a transparent brown liquid consisting of 10 parts potassium iodide (KI) to 5 parts iodine to 85 parts (distilled) water. It is an effective bactericide and fungicide and, in fact, was, for the better part of a century, a common antiseptic - though it has laboratory uses separate and apart from any medical application. Lugol’s and similar iodine solutions probably fell out of favour in the last half of the 20th century due to a combination of economics and aesthetics. First, it is so cheap to make that it cannot compare to ‘cleaner’, value-added antiseptics with more marketing muscle and secondly, it will stain clothes and will even temporarily stain skin when used topically to treat a wound. The internal applications of various iodine solutions have been published and discussed for well over a century.

Tincture of Iodine

Iodine’s use in the treatment of wounds was first described in 1839. By the late 1800s, iodine tinctures came into wide use as microbicides. Tincture of iodine is a solution of iodine and potassium iodide in alcohol.

Iodine Ointments

There were several formulae available in the first half of the 20th century and the following are suggestive of what may have been dispensed.

Mix the Iodine with the Arachis Oil in a wide mouthed bottle, loosely corked and heat in a water bath at 70 to 80oC until the brown colour has disappeared. Add the other ingredients previously melted, and stir until cold. Serious loss of Iodine occurs unless it is prepared in a closed vessel.

Note - Green to olive brown in colour, it contains only a trace of free iodine and does not stain the skin (ANZ Pharmaceutical Formulary, 1934).

The earliest forms of prophylaxis practised in Tasmania for the reduction and prevention of goitre was perhaps a combination of several formulations containing iodine. These would have included tincture of iodine, Lugols solution, iodine-based ointments, iodine paints and dessicated thyroid. It was only in the 1920s that iodised salt became available. Prior to this and following the first goitre survey conducted in the early 1920s, in Tasmania, families would often use iodine drops added to the children’s milk each day as a means of preventing goitre in the family.

Following the early survey of the 1920s on endemic goitre there appears to be a lengthy period of silence on the matter as there are no references in the parliamentary papers for the duration of the 1920s decade. However, in 1937, in the course of discussions in the Legislative Council, reference was made by a Mr Blacklow to the fact that he believed that much more could be done for the health of the people of Tasmania. He drew attention to this by saying:

One had only to walk the streets to see the large number of persons, particularly women, who were suffering from goitre.

He suggested that advanced steps were being taken, with successful results, in several countries of the world where this complaint had been common.

He also drew attention to the fact that there should be legislation introduced for the supply and compulsory use of iodine in domestic salt. In April of that year the Minister for Health on the subject, Compulsory use of iodine in domestic salt forwarded a letter to the Director of Public Health, B.M. Carruthers, requesting the Director’s observations on this matter (AOT).

The Director’s reply:-

The fact that goitre (enlargement of the thyroid gland) is endemic in certain parts of Tasmania, has been recognised for many years.

Prophylactic iodine treatment of simple goitre has yielded excellent results in many countries, and if commenced early reduces the incidence of the disease.

There are various ways of administering the iodine, the most satisfactory being iodised salt – one part of potassium iodide to 250,000 parts of table salt.

In Tasmania, the incidence of simple goitre is much greater in certain country districts than in the cities, and I know that in many cases the local practitioners have tried and instituted prophylactic measures. It is doubtful, however, if such measures could be made compulsory.

When the country medical officers’ scheme is inaugurated, a special survey of cases of goitre will be made, and prophylactic measures increased.

B.M. Curruthers

Director of Public Health

20/4/37 (AOT)

Not only were there concerns on the incidence of goitre particularly in young women being raised in Parliament but also from the general public as witnessed in a letter in February of that same year from Wilfred Partridge, proprietor of the Circular Head Chronicle, Stanley to the Secretary for Public Health.

Dear Sir, 3/2/37

Several girls and women in this town are supposed to be goitrous. Is this possible as we have sea on three sides of us? One is a girl of 14 working in my office who has lived here all her life. If it is goitre how can they take iodine without over-dosing.

The Director’s reply was simple and direct saying that it was possible for people living near the sea to be affected and that a medical practitioner should be consulted for treatment (Ibid).

The Department of Education in New South Wales, School Medical Service had prepared a small pamphlet titled ‘Goitre Enlargement of the Thyroid Gland’ which was issued for the guidance of parents of NSW school children, a copy of which was attached to the correspondence file cited on the subject of compulsory use of iodine in domestic salt. It was marked ‘Circular to be kept for Reference’. (AOT HSD1/1/2585).

In the 1930s, an Australian wide nutritional survey was undertaken.

Child Nutrition Survey a precursor to Goitre Survey

Several reports in the 1940s on child nutrition highlight several factors, which in retrospect may have contributed to the continuing incidence of goitre, especially in those country areas surveyed in the reports.

In 1935 a committee was appointed by the League of Nations to study the problems of nutrition in its relation to health. Following a two-year study, the committee produced a report in which it showed that malnutrition was widespread throughout the world. It was recommended from this study that countries set up their own national nutrition committees to study the question of how this condition could be overcome.

As a result Australia set up an Australian Advisory Council on Nutrition in 1935 and carried out a series of investigations in various parts of the Commonwealth. Two matters were highlighted:-

1. that there was much ignorance in the community as to the proper balance of food items; and

2. that some people in both town and country were unable to obtain, for various reasons, the essential fresh foods.

It was also clear from the report that malnutrition existed amongst young children in both town and country. This was attributed to poor food selection, ignorance and poverty leading to a state of malnutrition, however more often as a result of ignorance.

Tasmania was not included in the survey, but following the appointment of a permanent nutritional committee, food surveys were carried out in various parts of the Commonwealth in 1944.

References

Major, R.H., Classic descriptions of disease, 1939, pp. 273-82.

Marine, D., Kimball, OP, J Lab. Clin. Med., 1917, vol. 3, pp. 40-9.

Costa, A.B., In Dictionary of Scientific Biography, Gillispie, CC, Ed.: Charles Scribner’s Sons, New York, 1971, vol. 3, p. 455.

Courtois, B., Ann. Chim., 1813, vol. 88, pp. 304-10.

Kelly, F.C., Proc. R. Soc. Med., 1961, vol. 54, pp. 831-6.

Knight, D.M., In Dictionary of Scientific Biography, Gillispie, CC, Ed.: Charles Scribner’s Sons, New York, 1971, vol. 3, pp. 598-604.

Knight, D., Humphry Davy Science & Power, Blackwell, Oxford, 1992, pp. 94, 96, 97, 99-100. Davy, H, Philos. Trans. R. Soc., London, 1814, vol. 104, pp. 74-93. Rolleston, HD, The Endocrine Organs in Health and Disease, London, 1936.

Major, R.H., Classic descriptions of disease, 1939, p. 301.

Liston., R., ‘A Course of Lectures Operations of Surgert’, The Lancet, 9 Nov 1844, p. 189.

Berl. Klin. Wochenschr, 1870, vii, pp. 101-5.

Cor-BI f. Schweiz Basel Aerzte, 1878, viii, pp. 702-5.

Garrison, F.H., An Introduction to The History of Medicine, 3rd Edition, London, 1922.

Arch. f. klin. Chir., Berl., 1883, xxix, pp. 254-337

Boussingault, J.B., Ann. Chim. Phys., 1833, vol. 54, pp. 163–77.

Boussingault, J.B., Ann. Chim. Phys., 1831, vol. 48, pp. 41–69.

Ibid

Bellamy, P.G., ‘Efficacy of Iodine in Bronchoele’, The Lancet, 27 June 1828/9, p. 406.

The Family Physician, A Manual of Domestic Medicine, London, 1882.

Marine, D. and Kimball, O.P., J. Lab. Clin. Med., 1917, vol. 3, pp. 40–9.

Marine, D. and Kimball, O.P., Arch. Intern. Med., 1920, vol. 25, pp. 661–72.

Kohn, L.A., Bull. Hist. Med., 1975, vol. 49, pp. 389–99.

Kendall, E.C., J. Am. Med. Assoc., 1915, vol. 64, pp. 2042–3. Reprinted in J. Am. Med. Assoc., 1983, vol. 250, pp. 2045–6.

Kendall, E.C., Trans. Assoc. Am. Physicians, 1915, vol. 30, pp. 420–49.

Harington, C.R., Biochem. J., 1926, vol. 20, pp. 300–13.

The Australian and New Zealand Pharmaceutical Formulary, 6th Edition, 1934.

24) Sun, (Sydney), 21 September 1911, p. 1

25) Daily Post, 27 September 1911, p. 4

Medical Geology

The award-winning book Essentials to Medical Geology was first published in 2005 and helped stimulate the rapid development of medical geology. The book has been widely used as a textbook all over the world – at universities, in short courses and as a resource for researchers. It has become the primary reference book in medical geology. A revised version published in 2013 has been an invaluable resource of well researched work by over 60 internationally acclaimed academics.²⁶

This book emphasises the importance and interrelationships of geological processes to the health and diseases of humans and animals. Its accessible format fosters better communication between the health and geoscience communities by elucidating the geologic origins and flow of toxic elements in the environment that lead to human exposure through the consumption of food and water.

In the 21st century we saw at last communication between the medical profession and the earth scientists leading to a much better understanding of medical geology especially in the field of iodine deficiency. This link was exemplified here in Tasmania in 2006 when I invited Ron Fuge²⁷ from University College of Wales to participate in an iodine deficiency seminar as a keynote speaker.

Medical geology is a rapidly growing field concerned with the relationship between natural geological factors and human and animal health, as well as with improving our understanding of the influence of environmental factors on the geographical distribution of health problems.²⁸

It is well known and accepted that one of the biggest geochemical diseases is iodine deficiency. Thirty percent of the world is at risk of it and insufficient intake is the most common cause of mental retardation and brain damage. The sea is a major source of iodine and those who are further from it are at a disadvantage. Another source of it is in soil, however goitrogens, such as humus and clay, trap the iodine making it hard for people to access it. Some cultures actually consume the earth’s minerals by eating soil and clay; this is known as geophagy. It is most common in the tropics, especially among pregnant women. The Ottomac people of South America engage in this practice and none have suffered from any health problems related with mineral/iodine deficiency.²⁹

The impact of the natural environment on public health has been recognised for centuries. Hippocrates and Aristotle were the first to recognise the relationship between human diseases and the earth’s elements. Some have thought that medical geology is a new field when in actuality it is re-emerging.³⁰ Only now are people becoming aware of the effects the environment has on our health and the importance and interrelationships of geological processes to the health and diseases of humans and animals.

Iodine remains the classic success story in medical geology as far as human health is concerned. Iodine was the first element recognised as being essential to humans, and endemic goitre was the first disease to be related to environmental geochemistry.³¹ See soil map on page 115.

The British Geological Survey (BGS) commissioned report CR/03/057N ‘The geochemistry of iodine and its application to environmental strategies for reducing the risks from iodine deficiency disorders (IDD)’, by C.C. Johnson with a contribution from F.M. Fordyce, gives an excellent summary of iodine geochemistry in soils which has been studied in detail as this is the vital link between the food chain and the environment.³²

This is their summary:

The role of iodine in endemic goitre was the first recognised association between a trace element in the environment and human health. Medical intervention techniques such as salt iodisation have been successful in reducing the risks from iodine deficiency disorders (IDD) in many parts of the world. However, much of the effort in eliminating IDD proceeds without a sound understanding of its principal cause - a deficiency of iodine in the environment. This project funded by the UK Department for International Development (DFID) addresses the perceived need for a better understanding of iodine geochemistry so that we can ensure that the small amounts of iodine that are available in the environment are used in the most efficient way. Furthermore, iodine added through environmental supplementation techniques (e.g. adding iodine to irrigation waters) needs to be managed in an effective way to ensure maximum use is made of the added iodine through a better understanding of its geochemical behaviour.

This project uses data from BGS case studies in Sri Lanka, China and Morocco plus an extensive bibliography of iodine geochemistry. From this we have created databases on the iodine content of soils, food and drinking water.

The geochemistry of iodine in soils has been studied in detail as this is the vital link between the food chain and the environment. A model for the iodine content of soils is discussed based on locational factors, the iodine fixation potential of the soil and the important pathway of iodine from the ocean-atmosphere-land-plant-man. There is no simple correlation between the iodine content of a soil and its distance from the sea, though the coastal zone is clearly a high-iodine environment which is reflected by the high levels of iodine in water, soil and crops in such areas. Climate, topography and parent material all contribute to the iodine status of a soil which is determined by the interaction of numerous physical and chemical parameters. The iodine content of a soil depends not only on the supply of iodine, or lack of it, but the ability of the soil to fix the iodine, i.e. its iodine fixation potential. Organic matter plays a principal role in retaining iodine but other factors will contribute including soil texture, iron and aluminium oxides, clay minerals, water-logging, microbial activity and Eh and pH.

The oxidation potential and pH are fundamental in determining the form and mobility of iodine in a soil system. It is the mobile or bioavailable iodine present in the environment that should be of prime concern. Iodide is considered to be the more mobile and volatile form within the soil and is favoured by acidic soil conditions. Iodate is the less mobile form of iodine in soil and is favoured by dry oxidising alkaline conditions such as those found in thin soils developed on limestone. Methyl iodide and other volatile organic complexes of iodine appear to be generated by microbial and root