F&N Bulletin Vol 23 No 1b - United Nations University

90 C. Yamada and D. Oyunchimeg
reasons it may be difficult to scale up to a larger program.
However, it is extremely important for governments to
find ways to avoid a significant price differential between
iodated and noniodated salt, such as occurs in Mongolia.
Ideally there should be no difference in price between
salt with and without iodine, as in the United States, or
there should be universal iodation of salt, as in many
countries. The latter will not necessarily stop some locally
produced and consumed salt that is not iodated, but it
will ensure that the majority of the population receives
the benefits of iodated salt. Where commercially iodated
salt cannot be made available in rural areas without
significantly higher prices than that of unfortified locally
produced or contraband unfortified salt, the feasibility of
using village-level iodation, as described in the Letter to
the Editor, should be explored further.
Nevin Scrimshaw, Editor
References
1. Scrimshaw NS, Cabezas A, Castillo F, Mendez J. Effect of
potassium iodate on endemic goitre and protein bound
iodine levels in school-children. Lancet 1953;2:166–8.
2. Arroyave G, Pineda O, Scrimshaw NS. The stability
of potassium iodate in crude table salt. Bull WHO
1956;14:183–5.
Abstract
In Mongolia many households use iodized salt only
occasionally. We investigated whether the occasional use
of iodized salt had an impact on the reduction of goiter
size. We examined 685 children (8–11 years old) in five
groups of households that (1) used iodized salt regularly,
(2) used more than 10 kg of iodized salt annually, (3)
used 6 to 10 kg annually, (4) used less than 6 kg annually,
(5) and regularly used noniodized salt. The prevalence of
goiter as determined by ultrasound in these five groups
was 31.1%, 30.3%, 40.6%, 52.1%, 56.6%, respectively.
There was no difference between goiter rates among the
first three groups, but these groups had significantly
lower rates than the last two groups. We concluded that
annual use of more than 6 kg of iodized salt, preferably
more than 10 kg, by a household had a beneficial effect
on the rate of goiter. In addition, the possibility was
suggested that households that consumed only iodized
salt consumed less salt than other households.
Introduction
Iodine-deficiency disorders are a cause of goiter and
physical and neurological damage that in pregnancy
can permanently affect the infant [1]. Almost 1 billion
people worldwide are at risk of iodine-deficiency
disorders, and 20 million suffer from various degrees of
reduced cognitive performance [2]. Over 100 countries
recognize iodine-deficiency disorders as a public health
threat and have launched salt iodization programs to
control it [3].
Mongolia recognized this problem, mainly from the
high prevalence of goiter, and started the national salt
iodization program in 1996. The Mongolian Ministry
of Health and the Japan International Cooperation
Agency have conducted several monitoring studies of
iodine-deficiency disorder status and progress of the
iodine-deficiency disorder program throughout the
nation since 1996. We found that by 1998, 42% of the
salt consumed nationally was iodized [4], and that there
were obstacles to popularizing the use iodized salt, e.g.,
the higher price of iodized salt as compared with noniodized
salt and its poor distribution in rural areas [5].
Our study found that there were five groups of
households in Mongolia in terms of their usage of
iodized salt usage: (1) those that used only iodized
salt regularly, (2) those that used more than 10 kg of
iodized salt per year, (3) those that used between 6
and 10 kg of iodized salt per year, (4) those that used
less than 6 kg of iodized salt per year, and (5) those
that never used iodized salt. Approximately 20% of
households belonged to group 1, 30% to group 2, 30%
to groups 3 and 4 combined, and 20% to group 5 [6].
On the basis of the average daily salt intake of 14.6 g
by adult women in Mongolia [7] and the recommended
iodine intake in salt of 30 ± 10 ppm, those
who used iodized salt regularly, or who used both
iodized and noniodized salt, had an adequate intake of
iodine, i.e., at least 150 µg per day for adults and 90 to
120 µg for children [8]. Thus, households in categories
1 and 2 have sufficient iodine intake for the prevention
of iodine-deficiency disorders.
Unfortunately, because of its poor availability in
rural areas and its higher price as compared with
that of noniodized salt, many people in Mongolia
cannot use iodized salt every day. It was assumed
that even occasional iodine intake would be of some
benefit. However, no information was available on the
degree of effectiveness of occasional use of iodized salt.
Therefore, we performed a study to determine whether
iodine-deficiency disorder status is improved by the
occasional use of iodized salt at different levels.