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Monitoring of
Quality of Iodised Salt to Prevent Iodine Deficiency Disorders and Increase
Production of Iodised Salt through Networking of Medical Colleges in Andhra
Pradesh, Karnataka, Kerala, Tamil Nadu and
Human Nutrition Unit,
All
India Institute of Medical Sciences,
Ansari Nagar, New Delhi-110029
and
Salt
Department
Government
of
(Research
Project Sponsored by: UNICEF,
2002
Monitoring of Quality of Iodised Salt to Prevent Iodine
Deficiency Disorders and Increase Production of Iodised Salt through Networking
of Medical Colleges in Andhra Pradesh, Karnataka, Kerala, Tamil Nadu and
Human Nutrition Unit,
All India Institute of
Medical Sciences,
Ansari Nagar, New
Delhi-110029
and
Salt Department
Government of
(Research Project Sponsored
by : UNICEF,
2002
Contents
Acknowledgement
1. Introduction
2. Rationale
3. Objectives
4. Research Methodology
5. Results
Tables
6. Recommendations
7. Appendices
v.
Table depicting the simplified classification of goiter
Acknowledgement
We
would like to thank the Salt Commissioner, Government of
Central Co-ordinating Unit
AIIMS,
List of Abbreviations Used
AIIMS
All India Institute of Medical Sciences
DGHS
Directorate General of Health Services
GOI
Government of
IDD
Iodine Deficiency Disorders
IEC
Information Education and Communication
IS
Iodised Salt
IT
Iodometric Titration
LDPE
Low density polyethylene
NIDDCP
National Iodine Deficiency Disorder Control
Programme
PFA
Prevention of Food Adulteration
PHC
PI
Principal Investigator
PPS
Probability Proportionate to Size
STK
Spot Testing Kit
TGR
Total Goiter Rate
TSH
Thyroid Stimulating Hormone
UIE
Urinary Iodine Excretion
UT
Research Teams
Andhra Pradesh
Karnataka
Kerala
Central Co-ordinating Unit
(AIIMS)
1.
Dr. Umesh Kapil,
2. Ms. Preeti Singh,
3.
Ms. Priyali
Pathak,
*Could
not participate
1. Introduction
History of IDD
Endemic goiter in
The IDD is known to be a
significant public health problem in 118 countries. At least 1572 million
people world-wide are estimated to be at risk of IDD i.e. they live in areas
where iodine deficiency is prevalent (total goiter rates above 5%), and at
least 655 million of these are considered to be affected by goiter. A recent
WHO/UNICEF/ICCIDD report estimates that currently about
29% of the world's population live in areas of iodine deficiency and
need some form of iodine supplementation.
Most of these are in developing countries in
About
200 million people are at risk of IDD in
Etiology
Iodine is one of the essential elements required for normal human
growth and development. Its daily per capita requirement is 150 micrograms.
Soils from mountain ranges, such as the
The contribution
of different food groups to the daily intake
of iodine are cereals 40 per cent, milk and milk products 37
per cent, flesh foods
11 per cent, pulses 10 per
cent and vegetables 2 per cent. Cereals and pulses together contribute
significantly to the daily intake of iodine .
Iodine deficiency thus results mainly from geological rather
than social and economic conditions. It
cannot be eliminated by changing dietary
habits or by eating specific
kinds of foods grown in the same area . Besides
nutritional iodine deficiency, a
variety of other
environmental,
socio-cultural and economic factors operate
to aggravate iodine
deficiency and related thyroid dysfuncitons. These include poverty related
protein-energy malnutrition, ingestion of
goitrogens through unusual diets (particularly by the poor),
bacteriologically contaminated drinking
water, as well
as bulky high residue
diets which interfere with
intestinal absorption of iodine.
There is also evidence
to believe that intensive cropping, resulting in large scale removal of biomass from the soil,
as well as widespread use of alkaline
fertilizers, rapidly deplete the soil of its
iodine content. Since both
intensive cropping and use of
alkaline fertilizers are widely practiced in almost all states
of the country, it is not
surprising that nutritional iodine
deficiency and endemic goiter are seen wherever they are looked for in
India .
Several environmental and genetic factors
interfere with the above processes of
thyroxin synthesis leading
to goiter formation. The genetic factors, which are rare, mainly
affect the enzymes involved
in thyroxin synthesis.
Environmental factors are amongst the most common factors that interfere
in thyroxin synthesis and
lead to goiter formation. The most
important environmental factors are
(i) environmental iodine deficiency; and (ii) presence of
goitrogens. However, the most frequent
cause of goiter in
Besides iodine deficiency and goitrogens, a variety of other
factors can adversely affect efficient thyroxin synthesis
and iodine utilisation in the
body, resulting in aggravation
of goiter. These include, protein energy malnutrition,
dietary factors that interfere with iodine absorption, etc.
Environmental iodine deficiency coupled with a variety of ancillary factors
compromises thyroxin biosynthesis which results in prevalence of endemic goiter
.
Iodine deficiency in
food and water leads to less iodine
to thyroid gland which is the
exclusive organ for synthesis of two
very important iodine containing hormones T3 (Triiodothyronine) and T4
(Thyroxin). As a result, the thyroid
gland becomes hyper active to
produce the requisite amounts of T3
and T4 thereby enlarging itself by hyperplasia phenomenon under
compulsion and this enlargement of the
thyroid gland is known as goiter. In the
past, goiter was said to be a cosmetic problem, however,
the recent research studies have shown that goiter is one of the several disorders that the body is subjected to
suffer due to iodine deficiency. All the
disorders are currently being categorised under a term Iodine deficiency disorders (IDD). The relationship between dietary iodine intake and severity of IDD is shown in Appendix II.
The major factors responsible for iodine deficiencies are :
i)
Recurrent
flooding in the areas.
ii)
Heavy
rainfall/snowfall
ii) Removal
of great amount of biomass
due to multiple crops.
iii) Goitrogens in food, monotonously consumed by
the poor.
iv) Bacterial load of water, poor sanitation,
v)
PEM and
recurrent infection due to poverty.
Iodine deficiency has been
called the world's major cause of preventable mental retardation. Its severity
can vary from mild intellectual blunting to frank cretinism, a condition
that includes gross mental
retardation, deaf mutism, short stature, and various other defects. In areas
of severe iodine deficiency, the majority of individuals risk some degree
of mental impairment. The damage to the developing brain results in
individuals being poorly equipped
to fight disease,
learn, and work effectively, or
reproduce satisfactorily. The spectrum
of disorders caused
due to iodine deficiency affects all the stages of life - from
foetus to adult (Appendix III). If
a pregnant woman’s diet do not
contain adequate iodine, the foetus cannot produce enough thyroxin and foetal
growth is retarded. Hypothyroid fetuses often perish in the womb
and many infants die within a week of birth. The
current data on the embryology of the brain suggest that the critical
time for the effect of iodine
deficiency is the mid second trimester i.e. 14-18 weeks of
pregnancy. At this time neurons of the cerebral cortex and basal ganglia are
formed. It is also the time of formation of `Cochlea' (10-18 weeks)
which is
also severely effected in endemic
cretinism. A deficit in iodine or thyroid
hormones occuring during this
critical period of life results
in the slowing down of the metabolic activities of all
the cells of the
foetus and irreversible alterations
in the development of
brain. The growth and differentiation of the
central nervous system are closely related to the presence
of iodine and thyroid hormones. Hypothyroidism may lead to cellular hypoplasia and
reduced dendritic ramification
gemmules and interneuronal connections. Hypothyroid children
are intellectually subnormal and may also suffer physical impairment.
They lack the aptitudes of normal
children of similar age, and are often incapable of completing school.
Studies have documented that in areas
with an incidence of mild to moderate IDD, IQs
of school children are,
on an average, 10 –12 points
below those of children living in areas where there is no
iodine deficiency. Foetal
thyroid start secreting thyroxin early in
the 2nd trimester in
intra-uterine life. From then on till
the end of the
first year of post-natal life,
thyroxin plays a very
important role in the growth and functional maturation of the
foetal brain. Thyroxin deficiency
during this critical period
can result in impaired brain
development which cannot be corrected later by giving iodine or thyroxin.
The thyroid gland
in its present form evolved over
the course of millions of years of biological evolution. The molecule
of thyroxin has four atoms of
iodine. Therefore, iodine is an
essential element required for the
synthesis of thyroxin. The thyroid gland has very efficient
mechanisms for extracting iodine from
the circulation, where
it may be present in as low a concentration as
0.01 micrograms per 100 ml of
plasma. The minimum daily
requirement of iodine by thyroid gland in
man is estimated to be 100 micrograms. To extract this amount of iodine from the circulation, the thyroid daily clears
several hundreds of liters
of plasma of its iodine.
This work can
increase further by several
times in severely
iodine deficient
environments because of the very low concentrations of
iodine present in the circulation
in such conditions. To cope up with this increased work load, the thyroid
enlarges in size, under the influence of thyroid stimulating hormone (TSH),
secreted from the pituitary gland. The
efficient compensatory mechanism
triggered by low thyroxin feedback at the hypothalamic centers
lead to increased TSH secretion from the pituitary and
cause remarkable enlargement of the
thyroid gland resulting in goiter . Iodine as iodide (I-the ionic form) is
transported into the cells by the
iodide pump. This process is called
`trapping'. The trapped `iodine'
is enzymatically oxidised to free iodine and chemically linked
to a protein in
the thyroid cell
called thyroglobulin. In fact
the iodine is attached to the tyrosines
(an amino acid) of the thyroglobulin molecule.
The thyroglobulin so iodinated is secreted into the thyroid follicles.
Thyroxin is formed, iodinated and stored in the
thyroglobulin molecules. Under the influence of TSH, the thyroxin stored
as thyroglobulin in the thyroid acini is
released, in accordance with the needs of the
body. Synthesis of thyroxin in
the thyroid cells involve availability
of enough iodine to the thyroid, as well as action of a variety of
enzymes in the thyroid. If
any of these processes are affected thyroxin synthesis is impaired and
goiter formation results.
Endemic cretinism is the
extreme clinical manifestation of
severe hypothyroidism during
foetal, neonatal and childhood stages
of development. It
is characterised by
severe and irreversible mental
retardation, short stature, deaf-mutism, spastic dysplegia
and squint. In early eighties in
many seriously endemic terai districts of north India, average prevalence of 1-2% of cretinism was seen. The situation
has improved significantly with supply
of iodised salt and the cretins are no more born.
Cretinism seen in endemic areas is predominantly
of two types (a)
Neurological cretinism, where only
the neurological
manifestations of thyroxin deficiency
early in life (inutero) and dysplegia
and squint are seen. This is presumably
because, in such
individuals hypothyroidism was confined to the inutero or neonatal
stages of life. (b) Myxedematous cretinism where besides mental
retardation, myxoedema and dwarfism are seen. This variant of cretinism is
presumably because of continuing hypothyroidism through all phases of life.
ii) Cretinoids
Besides the few
who manifest as cretins, in an
endemic goiter area, a large number of individuals with lesser degrees
of mental retardation, speech and
hearing defects, psychomotor retardation, as
well as gait
defects may be
seen. Such individuals are
known as cretinoids.
The prevalence of cretinoids may
be tenfold or more, than fully manifested
cretins in severely endemic regions.
iii) Other syndromes due to foetal iodine deficiency
There is
preliminary scientific evidence suggesting that severe iodine deficiency can lead to
foetal wastage such as abortion,
still births, and congenital abnormalities. However, hard evidence available in this
regard is limited.
iv) Neonatal and childhood hypothyroidism
When the cause
of endemic goiter in the
Himalayas was investigated in the late fifties, modern techniques
for precise measurement of
thyroid hormones were not available.
In the sixties, and seventies,
when radio-immunoassay techniques became
available for sensitive
and precise measurement
of these hormones, it was discovered that more than 30%
the goitrous subjects in
endemic areas were functionally
decompensated and
hypothyroid despite the `adaptive' enlargement of the
thyroid. Subsequently, in early eighties by screening the cord blood of over 20,000 newborns, it was
discovered that one out of every 10 new
borns from the terai regions of UP were
hypothyroid at birth.
iv) Adult hypothyroidism
A large number of goitrous adults in an endemic region can have varying degrees of
hypothyroidism leading to a variety of clinical symptomatology and
complications related to
hypometabolic states. These
symptomatology can seriously hamper human energy and work capacity with resultant
erosion of economic productivity of endemic regions. Indeed
such factors may possibly
be contributing to
the known socio-economic backwardness of
endemic regions.
v) Goiter and its
complications
These are well known medical and surgical
problems which are also included in the syndrome of IDD. Besides, there is
emerging epidemiological evidence linking
endemic goiter with
incidence thyroid cancer.
Following the successful
trial of iodized salt in the Kangra valley of Himachal Pradesh, a National
Goiter Control Programme was launched by
the Government of India in 1962. The
programme was renamed as National Iodine Deficiency Disorders Control Programme
in eighties.
Objectives
: National IDD Control Programme has the following objectives:
i)
Initial surveys
to assess the magnitude of the iodine deficiency disorders.
ii)
Supply
of iodised salt in place of common salt.
iii) Resurveys to assess the impact of iodised
salt after every 5 years.
Beneficiaries
All people residing in endemic and non-endemic areas
for IDD. The population
in known endemic areas
are given priority.
Activities and services provided under the
NIDDCP
i. Production and distribution of iodised salt
On the recommendations of Central Council of Health in 1984,
the Government took policy decision to
iodise the entire edible salt in
the country. This
policy decision was implemented w.e.f. April, 1986 in a phased manner. Subsequently the iodised salt production was liberalized to private sector. Six
hundred forty one private manufactures have been
licensed by Salt Commissioner for production of iodised salt. These have
annual iodised salt production
capacity of more than 60 lakh
tons (which is adequate
for the entire country). The
annual production of iodised salt has increased
from 5 lakh metric tons in 1985-86 to 45
lakh metric tons in
1998-99. This is expected to rise
further to 52
lakh metric tones in near future which is the projected national requirements .
Financial assistance is
provided to Salt
Department for monitoring
the quality control of iodised salt
produced at production
level. The Salt Commissioner in
consultation with the Ministry of the Railways
arranges for the transportation of iodised salt from the production centres
to the consuming States under priority
category `B', a priority second
to that for defence
.The Salt Deaprtment has been initiating action to improve packaging
of iodised salt to prevent iodine loss
during transit. The State governments have been advised to include iodised salt
under Public Distribution System (PDS).
ii. Notification for banning the use of
non-iodised salt
To ensure the use of only iodised
salt sale of non-iodised salt has
been completely banned
under Prevention of
food Adulteration Act, 1954, in all states and union
territories, except Kerala.
Realizing the importance of iodine deficiency in
relation to human resource
development, NIDDCP has been included in 20
point Program of the Prime
Minister for monitoring the progress.
iii. Establishment of
goiter cell
For effective monitoring and proper implementation of NIDDCP, all the states and UTs have been advised
to establish IDD control Cell in the
State Health Directorate.
Government of India provides budget for this purpose. Presently 26 states and union territories have established NIDDCP cells
iv. Information education
and communication activities
Central Government provides
cash grants to the states and UTs
for production of health education
material and carrying out health
education activities on
IDD as well
as for undertaking IDD
surveys. To intensify the
IEC activities a communication package by way of video
films, posters/danglers and radio/TV
spots has been produced. TV video spots
are being regularly telecaste
through the National Network of Doordarshan
about the consequences of iodine deficiency
and the benefits of consuming
iodised salt.
The standards for iodised salt have been laid down
under PFA, 1954. These stipulate that the iodine content of
salt at
the production and consumption level
be at least 30 and 15 ppm, respectively. Under a GOI-UNICEF project intensive monitoring and
IEC activities was recently undertaken in
selected districts of India.
v. Intersectoral
co-ordination
It has been
realised that NIDDCP
activities require integrated efforts
of multiple agencies like Industry,
Railways, Health, Education, Food
and Civil Supplies, Information
and Broadcasting, etc. The focus
of NIDDCP activities has now been
shifted from only
health department to
multi and interdisciplinary
participation.
vi. Laboratory
support
A National Reference
Laboratory for monitoring of IDD has been
set up at the Bio-chemistry division of National Institute of
Communicable Diseases, Delhi
for training medical
and paramedical personnel and
monitoring the iodine content of salt
and urine.
District level IDD
monitoring laboratories are being setup
in all
the states for estimation of iodine content of salt and urinary
iodine excretion. These two laboratory investigations are the most effective tools for proper monitoring implementation of
IDD control programme. For ensuring
the quality control
of iodised salt
at consumption level, testing kits for "on the spot"
qualitative testing have been
distributed to all
district health functionaries for creating awareness about consumption
and use of iodised salt.
vii. Training under NIDDCP programmes
Every year, training programmes are being conducted in management and monitoring of NIDDCP for the Regional Directors of Health and Family Welfare
and the state level technical officers
by the Directorate General of Health Services. Training Programmes
for laboratory technicians
from the state level IDD monitoring laboratories are
also organised by the Directorate General of Health Services
every year.
viii Evaluation
The status of salt
iodisation in different states has been
extensively assessed by different research studies
and by national level surveys in
recent years . The NFHS‑2 was one of the largest survey which covered
all the states in the country with a representative sample of households . Thee
degree of iodization of salt used in
households was assessed. It was found that more than 70% population was consuming
iodised salt. (Appendix IV). The research studies conducted has identified following areas which
require strengthening :-
i) Irregular distribution of iodised salt for varying periods
ii) Lack of monitoring of quality of iodised salt distributed.
iii) Failure of lifting of
allotted quotas of iodised salt by wholesale agents for further distribution
to retailers.
iv) Inadequate
coordination between salt
dealers and food inspectors (the
implementors of PFA Act
causing disruption in the sale of iodised salt).
v) Poor coordination between
various departments like Food and
Civil Supply, Health, Industry,
Railways.
vi) Non - issue complete ban notification by all the states for the sale of non-iodised salt.
vii) Non-establishment
of IDD Control
Cell in all the states/UTs.
viii) IDD Monitoring Laboratories is yet to be set up
by all the states.
ix) Inadequate enforcement
of PFA act by the
state/UT governments to ensure
that quality of iodised salt is available to the consumer
x) Regular IDD surveys
are being not conducted by
the state/UT governments to
monitor the progress/identify new
areas of endemicity
Safety of Iodised Salt
Iodine requirements
have been calculated
based on (i) average daily physiological loss of
iodine in the urine which is 100-200 mg/day;
and (ii) balance studies to get
equilibrium or positive balance which is 44-162 mg/day.
These studies have estimated a safe
daily intake of iodine between a minimum of 50 mg
and a maximum of at least 1000 mg.
The generally accepted desirable adult
intake is 100-300 mg/day. In India the
current recommended dietary
iodine intake for adult is 150 mg/day.
The average salt intake among adults is about
10g/day, and at the
current level of fortification of salt with 15 ppm of iodine at the consumer level , the
iodised salt provides an additional
amount of about
73.5 mg
only (considering the
losses during cooking
and biological availability). The remaining requirement of iodine is met
from the dietary sources. Thus, the
total intake of iodine is much below the safe limit and therefore the
iodised salt is unlikely to cause
any harmful effects even in
populations who are not iodine deficient. Also it has been documented that at
all intake levels, a proportionate amount of
iodine is excreted in the urine.
The recent research studies conducted by Human
Nutrition Unit, AIIMS, New Delhi amongst
the children have clearly
documented that the UIE levels are
within the physiological limits i.e. 100 mg to 200 mg
per liter. Also, an analysis of more than
10,000 salt samples collected from different parts of country
revealed that only 2.5% of salt samples
had iodine content more than 60 ppm
and 82%
had less than 45 ppm . These findings indicated that currently fortification of salt
with iodine is
done as per the
recommended norms of Government of India. In view of all
scientific evidence the idoised salt
is safe.
Assessment of IDD
Probability proportionate to
size (PPS) cluster sampling methodology
is recommended. The thirty clusters should be
covered and should be selected as follows. Firstly all
population units/villages in the
area to be surveyed is listed along
with the population. Secondly,
the cumulative frequency table is prepared and
the total population in the
survey area is calculated. Then by dividing total population with 30, the
sampling interval is calculated. Subsequently the first
cluster is selected
at random and subsequent clusters are calculated by
adding sampling interval. The
number of subjects to be surveyed within each
cluster depends on (i) estimated prevalence of IDD; (ii) level of
precision desired; and (iii) variability of prevalence between clusters.
ii. Selection of target groups for
IDD survey
The survey should be
conducted in a representative sample of population. The school age children who
reflect the IDD status of the
community, are vulnerable to deficiency and respond to the iodine
supplementation intervention and hence have been recommended for the survey
iii. Indicators for assessing
IDD
The common indicators for assessment of IDD
are clinical and biochemical indicators. It is recommended that the assessment
of iodine content of salt consumed by the subjects should also be included in
the survey as data on this aspect
provides the guideline for developing the intervention for prevention of IDD
simultaneously.
iv. Clinical indicators
The size of the thyroid gland
changes inversely in response to
alterations in iodine intake,
with a lag of 6-12 months in children and young adults (i.e.
<30 years of age). The traditional method
for determining thyroid size is inspection and
palpation. Palpation of the thyroid is important in assessing goiter
prevalence. Cost is minimal. It is
relatively easy to conduct. The
training of personnel can be done. Children 6-12 years of age should be
studied. Very young children have
smaller thyroid and it is more difficult to perform
palpation. It is recommended that
if the proportion of children attending school is less than 50%, spot surveys
should be done on two groups
of children of the same age, i.e.
those who attend
school and those
who do not, to ascertain if
there is any significant difference between the two.
If so, both groups should be studied
separately, in all
clusters, or an
appropriate adjustment should
be made in
the rate found
among school children.
A modification of the
previous goiter classification system,
which defined five grades, is
recommended. The previously used
grades 1A and 1B are thus
combined into one, and grades 2 and
3 are combined
into another (Appendix
V). Appendix VI gives
the epidemiological criteria for establishing IDD severity based
on goiter prevalence in school age children. It is
recommended that a total
goiter rate (TGR, Goiter
grades 1 and 2) of 5% or more in primary school children
(age range approximately 6 to 12
years) be used to signal the presence of
a public health problem. This recommendation is based on the observation that
in a normal, iodine replete
population the prevalence of
goiter should be quite low. The
cut off
value of 5% allows some
margin of inaccuracy of goiter assessment and
for goiter that may occur in iodine replete population due to other causes
such as goitrogens and autoimmune thyroid diseases.
The previously recommended 10%
cut off level
has been revised downwards since it has been shown that goiter prevalence
rates between 5% and
10% may be
associated with a
range of abnormalities, including
inadequate urinary iodine
excretion and/or sub normal
levels of TSH among adults,
children and neonates.
The specificity and sensitivity
of palpation are low
in grades 0
and 1 due to a high
inter observer variation.
As demonstrated by studies of
experienced examiners,
misclassification can be as high as 40%. Measurement of urinary
iodine levels (in an adequate sample) is essential to decide
whether an iodine
deficiency problem is
of public health
importance.
v. Biochemical indicators
Urinary iodine
Since most iodine that is
absorbed is excreted the urinary iodine level is a good marker of a previous
day's dietary iodine intake. However, since an individual's urinary iodine
level varies daily and even during a given day, data can be used only for
making a population based estimate. Experience has shown that the iodine
concentration in early morning urine specimens (child or
adult) provides an
adequate assessment of a population's iodine status; 24-hour samples are
not necessary. Acceptability is very high and spot urine specimens are easy to
obtain. Urinary iodine assay methods are
not difficult to learn or use, but meticulous attention is required to avoid contamination with iodine at all
stages. Special rooms, glassware and reagents should be set aside solely for
this purpose.
Small amount (0.5-1.0ml) of
urine is required. Specimens are collected in tubes, which are tightly sealed
with screw tops. They do not require
refrigeration or the
addition of a preservative. Iodine content remains
stable throughout transport to the laboratory. The tightly sealed specimens
can be refrigerated in the laboratory for several months
before actual determinations are
made. Should evaporation occur,
iodine concentration will increase.
Since casual specimens are
used, it is desirable to measure about 300 samples from a given population
group to allow for varying degrees of subject hydration and other
biological variations between
individuals, as well as to
obtain a
reasonably small confidence
interval. Smaller sample sizes
are adequate to establish at the outset that iodine deficiency is the cause of
the endemic goiter. The cut off points proposed for classifying iodine
deficiency into different degrees of public health significance are
shown in Appendix VII. Frequency distribution curves are necessary for
full interpretation, since urinary iodine values from populations are usually
not normally distributed and therefore the median value should
be used rather than the mean.
The indicator of
iodine deficiency
"elimination" is a
median value for
iodine concentration of 100 mg/l, i.e 50% of the samples
should be above 100 mg/l,
and not more than 20% of samples should be
below 50 mg/l. As an
IDD prevention programme
progresses, goiter rates become
progressively less and
urinary iodine levels progressively more useful, as
elimination criteria.
New frontiers in
the field of IDD
A disturbing finding in recent years is the emergence of new
goiter-endemic areas in the irrigated plains of
country. The precise factors underlying this have not been identified;
but it is being
suspected that the
modern practice of
intensive agricultural
technology could have resulted in
the
diminished bioavailability
of soil iodine and the
consequent diminished content of
iodine in food and water. The possible
role of an excessive
use of fertilizers, pesticides and food additives
has also been suspected. The possibility that
goitrogens may be involved
in the emergence
of new goiter-endemic areas
is suggested by the finding of
high levels of urinary excretion of
thiocyanate in a significant proportion of subjects
in these areas. Peroxidase
inhibiting goitrogens have
been suspected to interfere with the effective utilization
of iodine by the thyroid gland. Such
goitrogens could be either present in foods
or as food contaminants. The
possible role of selenium deficiency in aggravating the goiter problem also requires
investigations. It is becoming
clear that problems of iodine deficiency
are acquiring new dimensions in the context of intensive agricultural
technology and ecological and environmental factors incidental to 'development' In combating these new dimensions we may have
to look for strategies
other than (and over
and above) the conventional approach of the fortification of common salt
with iodine.
2.
Rationale of the Study
In 1984, on the
recommendations of Central
Council of Health, the
Government took a policy decision to
iodise the entire edible
salt in the country by 1992.
The iodised salt production was
liberalized to private
sector. About 641 private
manufactures have been given license by Salt Commissioner, of which nearly
593 units have commenced production.
These units have annual production capacity of iodised salt of
more than 60 lakh tons which is adequate for the entire country.
The status of salt iodisation in different states
has been
assessed by research studies in
recent years. The available data shows that the strategy of salt iodisation has been
successful in the country (Appendix IV). However,
states like Tamil
Nadu, Kerala, Karnataka, Andhra
Pradesh and Pondicherry
require further
strengthening in their efforts for universal
salt iodisation programme. There
are possibly two main reasons for inadequate consumption of iodised salt
(i) ineffective implementation of ban
notification on sale of non-iodised
salt, and (ii) low priority being given by the state
governments for the prevention of IDD.
Iodine
deficiency disorders are a public health problem in the states of Tamil Nadu, Kerala, Karnataka, Andhra Pradesh and
Pondicherry as per the findings of the research survey conducted in these state
(Appendix VIII).
3.
Objectives of the
Study
(i)
To utilise the network of medical colleges for assessing the
iodine content of
the salt in different districts
in their region.
(ii) To undertake IEC
activities in the selected blocks to create awareness amongst beneficiaries to demand and
consume only iodised salt.
iii) Sensitisation
of the district and block level
functionaries of various departments participating in the NIDDCP
programme about benefits of iodised salt.
4. Research Methodology
A
rapid survey was conducted during July to November, 2001 to assess the status
of quality of iodised salt available in all the districts of Andhra
Pradesh, Karnataka, Kerala, Pondicherry and Tamil Nadu. In these states
36 medical colleges were included in the study. In each medical college, one
faculty member from the speciality of
Preventive and Social Medicine
who had a research interest
in the field of IDD
was identified. He was designated
as principle co-investigator of the
research project. Each principle
co-investigator surveyed 3-4 districts
(Appendix X).
Sampling
Methodology
In each district all High School/Senior
Secondary Schools were enlisted and one school was selected by random sampling
for the detailed study.
The following activities were undertaken on first
day of the survey
In
High School/Senior Secondary School selected for the survey, about 300 children from different villages attending
the school on the day of the survey were
identified and included in the
study.
The
following steps were followed :
(i) PI
went to each class and explained the
students about the objectives of survey,
the importance of iodine in salt and it’s role in prevention
of ill effects of iodine
deficiency.
(ii) Each
child was given an identification slip and auto-seal LDPE pouch for bringing
the salt sample.
(iii) PI demonstrated to the school children “how
to open auto-seal LDPE pouch and
how to close it again”.
(iv) Each
child was explained how and what information should be filled in the
identification slip by him/her. On each slip student was requested to write his name and class and section, name of village, block and
district.
(v) Each Child was requested to bring about
20 g of salt from their family kitchen.
(vi) Children from
different villages were
included in survey
to have information on iodised salt status
from maximum number of villages
in the block.
(2)
Collection of salt samples from
traders level
Salt samples were also collected from traders
in district and village in which school selected for study was loacted.
The iodine content of salt was analysed with the help
of STK and the results were communicated to Central Co-ordinating Unit,
AIIMS,
STATE
Medical
Medical Medical Medical
College College College College
District
District District District
I II III IV
List of all High
School/
1 High School/Senior Secondary School selected
Selection of 300 children from different
villages attending the school
150 salt samples 150
samples tested
sent to AIIMS at the school
Analysis of iodine content Analysis
of iodine content
of salt by IT method of salt by STK method
Results
discussed
With
district and block
level
functionaries
FLOW CHART OF METHODOLOGY
The
following activities were undertaken on second day of the survey
(i) Salt samples were
collected from school children.
(ii)
The iodine content of 150 salt samples or more was analysed
with the help of STK in the
school itself.
(iii) The iodine
content of salt samples
collected from traders was analysed with the help of STK.
(iv) The results
of salt samples analysed by STK were communicated to the School principal.
(v) A
sensitisation meeting on IDD and its consequences was held with district level
functionaries of various
departments participating in
the NIDDCP programme and the results of salt samples
collected from the beneficiaries
and traders with the help of STK were
discussed with them.
(vi) One hundred fifty salt samples were
sent to AIIMS for estimation of iodine content of
salt by IT method.
6. Results
ANDHRA
PRADESH
The
study was conducted in all the 23 districts of the state. A total of 3706 salt
samples were collected from beneficiary levels and it was revealed that only
18.5% of the population was consuming salt with the stipulated level of iodine i.e.
15ppm and more (Table I).
The
district-wise distribution of iodine content of salt is depicted in Table II.
It was observed that 55% of the families
were consuming iodised salt with 5 ppm
and more iodine. In the coastal districts of
A
total of 348 salt samples were collected from traders. It was observed
that only 36.7% of the samples at
village level traders and 45.5% of the samples at district level traders had
iodine content of 15ppm and more (Table
III).
The
details of each district in which survey was conducted has been depicted in Table IV. It was found that on an
average salt samples were collected from 10 villages (range: 5-45) in each
district. The District level sensitization meeting on benefits of iodised salt
was conducted in 16 out of 23 districts.
Table
V depicts the district-wise distribution
of UIE levels. It was found that
districts Rangareddy and Cuddapah had median UIE less than 100.0 μg/l and also
more than 20% of the urine samples
had UIE levels less than 50 μg/l indicating deficient iodine
nutriture in the population included in the survey in two districts. In both these districts, more than 60% of the families were found to be
consuming iodised salt with less than 5
ppm of iodine.
Table
I
Iodine content
of total salt samples
collected at beneficiaries
level in Andhra Pradesh,
Karnataka, Kerala, Pondicherry and Tamil Nadu
(n=14,285)
|
State
surveyed |
No.
of districts |
Sample
size |
Iodine content (ppm) <15 15 & more |
|
Andhra Pradesh |
23 |
3706 |
3021(81.5)
685(18.5) |
|
Karnataka |
25 |
3980 |
3350(84.2)
630(15.8) |
|
Kerala |
14 |
2110 |
1187(56.3)
923(43.7) |
|
|
4 |
600 |
497(82.8) 103(17.2) |
|
Tamil Nadu |
24 |
3889 |
3258(83.8)
631(16.2) |
|
Total |
90 |
14285 |
11313(79.2)
2972(20.8) |
Figures in parenthesis denote percentages
Table II
Iodine content of
salt samples collected
at beneficiaries level
in different districts in Andhra Pradesh
(n=3706)
|
Name of the district |
N |
Iodine content in
ppm |
||
|
<5 |
5-<15 |
15 ppm & more |
||
|
Nellore |
119 |
95(79.8) |
21(17.6) |
3(2.5) |
|
Rangareddy |
204 |
134(65.7) |
62(30.4) |
8(3.9) |
|
Vishakhapatnam |
205 |
156(76.1) |
39(19.0) |
10(4.9) |
|
Anantpur |
155 |
78(50.3) |
69(44.5) |
8(5.2) |
|
East Godavari |
152 |
63(41.4) |
79(52.0) |
10(6.6) |
|
Kurnool |
106 |
9(8.5) |
88(83.0) |
9(8.5) |
|
Prakasam |
150 |
125(83.3) |
11(7.3) |
14(9.3) |
|
Mehboobnagar |
100 |
13(13.0) |
77(77.0) |
10(10.0) |
|
Cuddapah |
155 |
94(60.6) |
43(27.7) |
18(11.6) |
|
Nalgonda |
150 |
93(62.0) |
38(25.3) |
19(12.7) |
|
Srikakulam |
205 |
25(12.2) |
153(74.6) |
27(13.2) |
|
Warangal |
158 |
69(43.7) |
67(42.4) |
22(13.9) |
|
West Godavari |
148 |
77(52.0) |
50(33.8) |
21(14.2) |
|
Chitoor |
183 |
61(33.3) |
84(45.9) |
38(20.8) |
|
Vijaynagram |
211 |
93(44.1) |
72(34.1) |
46(21.8) |
|
Nizambad |
200 |
110(55.0) |
46(23.0) |
44(22.0) |
|
|
150 |
107(71.3) |
6(4.0) |
37(24.7) |
|
Khammam |
150 |
79(52.7) |
33(22.0) |
38(25.3) |
|
|
150 |
60(40.0) |
43(28.7) |
47(31.3) |
|
Adilabad |
155 |
34(21.9) |
70(45.2) |
51(32.9) |
|
Medak |
150 |
61(40.7) |
37(24.7) |
52(34.6) |
|
|
200 |
4(2.0) |
114(57.0) |
82(41.0) |
|
Karimnagar |
150 |
23(15.3) |
56(37.3) |
71(47.4) |
|
TOTAL |
3706 |
1663(44.9) |
1358(36.6) |
685(18.5) |
Figures in parenthesis denote percentages