IODINE

Hokitika Guardian, 11 July 1930, Page 3

IODINE

A VITAL ELEMENT.

ESSENTIAL TO HEALTH

LOCAL INVESTIGATION. To the group of what may lie con s.'dered as indispensable vital clement has recently been added the newcomer —iodine, and the recognition of • tin importance of iodine is growing every day. lodine, which is found in soils in waters, and in the vegetable kingdom, was discovered during the great development of exact chemical research which took place at the beginning of the nineteenth, century, when many new elements were discovered. It was first found in 1811, in the ash of seaweed. It may .seem remarkable nowadays that anyone should have conceived the idea, at such an early stage in the history of scientific research, of making a min ute examination of the ash of seaplants, but the explanation lies in the wisdom of tlie ancients, for from time immemorial the ash of-sen-plants, and especially of seaweed, lias been known as a remedy for goitre.

The connection of iodine with livin'-' function was therefore known from the moment of its discovery. At first it was f bought to be efficacious ‘ only against one specific disturbance of the pr-cesse' of life-, that which showed itself in til”' ‘Toiterous degeneration of the tb-i-roid o-land. No suggestion was made tba 4 iodine was anything hut a therapeutic agent. But iodine was proved to bo more than this, although the fact was not recognised for some time. lodine 's now looked upon as having a definite ,-o„i ri £-j c;i i significance. Tt i-s probably ind’so usable- to the process of f ho 11 lug body. When it is not present :, i the nourishment in sufficient, quant' 4 -” disturbances arise through the inability of tlie thyroid gland, wherein 'he iodine is .stored as a upiform chemical opy. to ner f orm its functions completely. Sin o e the thyriod is the most -Vin—regulating organ in the vhnV met°’'olic chain, and since it e-ontrols ot I 'w parts of the endocrine system, a d■ feet in its function mean" a en-nre db-turhance of many of th r most important function of the body.

Mo’v points, however, about the significance of iodine still remain obscure. Experiments have shown the scone o r >io emblem to be almost limitless ‘n-irt from the goitre question, which applies to stock as well as to human b°ing. iodine would appear to play a verv important part in stock-breeding and in agriculture, and in the immediate future iodine is going to loom very large ..upon the horizon. There is iodine ,in the air, in seawater, in the soil, in fresh water, and in vegetables, lint only in very minute quantities. Ohr daily intake of iodine is smajl; the average individual probably uses only about 25 milligrammes Jess than half a grain) in a whole yea “"hildren perhaps need more. Less th°” Uiis oiiantify apparently leads to th r ’uftidence of goitre. Goitre is generally considered to be a primary disturb a nee of the function of the thyroid dim to lack of iodine. The nnatomicn 1 and pathological changes and the en 'argument represent an attempt of th r organ to utilise every possible means o' secreting its hormone b.v increasing its size. Therefore one would expect t' n 'nd in districts where iodine is prcsenl hi comparatiel.v large quentites an absence of goitre, and a high pereeutage of goitre in places where iodine >s relatively scarce. With some marked exceptions, this is generally true, and evidence is accumulating to show that the administration of iodine in tlm form of one of its salts in districts where an iodine deficiency occurs tends to reduce the goitre percentage.

OITRE IN THE NORTH ISLAND

The goitre percentage amongst New. Zealand children is disquietihgly high. Dr R. A. Shore f of the Health Department, pointed out at the last meeting of the Wellington Philosophical Society that of 24,000 children examined in certain districts of the North Island 24 per cent of the hoys and 26 per cent of the girls showed some degree of goitre. These figures, when compared with those of some other countries, lie pointed out, might seem alarmingly high, but it should be remembered that these figures included cases where the signs were slight, cases which authorities elsewhere did not include in their figures. He finds that an inverse relationship between the amount of soil ’odine and the percentage of goitre cases exists in most cases, although ‘■here are unexplained anomalies. “These anomalies, however,” he says “may indicate that the amount of ; odine supplied to the body is only one f'<nt a verv important one! factor involved in the production of goitre. The amount of iodine available in the great majority of instances seems to be the Predominating factor. Further work in those districts were tlm inverse rela tionship existing between the amount of iodine and the percentage of goitre appears to be upset may reveal another source of iodine, or may reveal another presence of some other factor nr factors. The great difference between the incidence of goitre in a low-iodine area and lfigh-iodine area is too significant to be a mere coincidence. One nui,st conclude that the amount of iodine available does apparently exercise a predominating influence on the incidence, of goitre.”

lODINE IN SOILS AND WATERS. ‘ At tlie same meeting of the Wellington Philosophical Society Mr R. L. Andrew, of the Dominion Laboratory, detailed the results of his analyses for iodine of many North Island soils and waters. In tlie city of Wellington, its suburbs, and neighbourhood tlie amounts vary extensively. As Jar as sfeils are concerned, the poorest contain .only 10 parts of iodine in, 10 million. These were sandy soils near sea I caches (Eastborne and Seatoun). In parts of Karori iodine was present to the extent of 190.t0 240 parts in 10 nillion. City .soils on an average eon•vlied B 3 parts in 10 million. The T >iH Valley average increases on proceeding up the valley from the sea, the middle and upper portion containing approximately twice (07 parts in 10 million) and three times (f - parts in 10 million) respectively the amount present in the lower portion (36 parts in 10 million).

The series of waters examined in tii' Wellington area is very complete. In the Ilutt Valley, the Ravine waters— Kardkoro (upland surface) and artesian—contain equal amounts of iodine. Three samples of Lower Hutt water examined in 1927 contain half the amount of iodine found in

t’etone water, hut a sample examined :, i .*1.928 contains slightly more than B'etone water. The iodine content of ‘-.Up Tuner Hutt town supply is equal *-'•> that of Petone water. Wainui-o-mata and Karori (Wellington City supply) contain equal amounts of iodne. and are .similar in that respeet 'o Retone and Tipper Hutt waters. Orongoronso ''Wellington City supply) contains half the iodine found in Wai-nej-o-mata- water. These results indithat tlie main water-supplies of "he area fall into two classes as regards their iodine content. Lower Hutt (artes'an) and Orongorongo (uphand surface) are the poorest, containing 0.0 microgrammes of iodine per ’ : tre; while Petone (bo+h upland snr"°ce and artesian). Wainui-o-mata, ' T pner Hutt and Ka>-nri waters con"in about twice that amount. Several of the small isolated -supplies conMii larger amounts of iodine. A shal•nv'well at Si'verstream (middle por‘•"l of Hutt Valley) contains 3.0 mic’,,vgrammes per litre: the water from the Grant road spring (Wellington) contains 4.5 microgrammes per litre: Jobnsonvillc town supply •untains 5.0 mirogrammes per litre. These quantities are exceeded by that in the water from a 450 ft artesian h«re in Torv street, Wellington, which contains 8.5 mogreirammes per litre. These small supplies all come from springs. It is therefore probable that they derive iodine from the rock-mass-es through which they percolate.

DEFICIENT W A TER S. y \ Tf the average amount of water consumed in actual fluid form he taken as about 2 1-3 pints a day, the annual consumption would be about 500 litres. Tlie amount of iodine per year -sup plied by the waters of Wellington would be from 0.3 to 0.6 milligrammes a year. But as a human being requires from 16 to 55 milligrammes a vear according to age, none of the notable - waters used in Wellington have any significance as a- source < 1 ulin". Even if Wellingtonians dran’-sea-water all the year round, only 10 milligrammes of iodine a year would he taken «ntn the system.

v ’o correlation between tlie iodim content of the soils and of the w: tops has been found in tbe various -.iistrets examined. Tn Wellington both tbe roils and the main water-supplies are ! ow, although, some of the minor wate>'cmplies are of high iodine content. At "'+rki, Levin, Shannon, Foxton, aiid 1 'bncr.ston North some soils are low •Mid ethers contain moderate amounts <■' iedine. Tlie upland surface waters -•••' low, but artesian waters at Levin and Foxton are very high in iodine. 1 the soils are low and tlie water high in iodine, but in. Taranaki the soils are high and the water very ’ At Wailii soils are high and

"—+cr low. while at Thames both soils '”5 wn+ers arc low in iodine. At T'l-oni'Mide! some soils are low and others extremely high, while tbe water is low in iodine.

One of the most remarkable springs ana'vsed in the' North Island was the *Tnk>d-]>vin artesian bore. This is a remarkable water as regards iodine content. It contains a considerable amount of organic matter having a distinctly brown colour, and its iodine content is 150.0 microgrhmmes mf mdine per litre, which is one hun.'lr,,d times that of the tvnical upland surface, waters of the Wellington and rT o>'owhenua areas, and about'; seven times that of sea water. It is not used for drinking purposes. lODISED SAIT. The use of iodised salt in districts where natural iodine seems to be deficient has been strongly advocated, but such advice has not keen taken very extensively, according to Dr. Shore. Calculating on the basis of five pounds per head a year, the people of the Dominion would require 68,cwt. The import figures, however, cwt. The import figures however, ■’ r>w that iodised salt coming into the country ,is less than one-sixth of the actual requirements of the population. about 50 per cent, going to the South {lsland.; “‘No opinion is expressed as to the value of iodised salt as a preventive, and until a re-sur-vey is made of an area where the salt has been extensively used such an opinion would he based on mere says Dr Shore. ‘‘The amount of'iodised salt used in North Island is, after three year's’ propaganda, somewhat disappointing.”