Iodine level concentration, coverage of adequately iodized salt consumption and factors affecting proper iodized salt utilization among households in North Ethiopia: a community based cross sectional study

Iodine is an essential micronutrient for the regulation of physical growth and neural development. The daily requirement of iodine for adults is 150 micrograms [1]. Healthy humans require iodine as an essential component of the thyroid hormones, thyroxine and triiodothyronine. Failure to have adequate iodine leads to inadequate hormone and pituitary to produce Thyroid Stimulating Hormone (TSH) which results in goiters. Inadequate hormones affect many different parts of the body, particularly muscles, the heart, the liver, kidneys, and the developing brain in which collectively known as Iodine Deficiency Disorders (IDDs) [2].

IDDs remain as a significant public health problem in many countries [3]. About 1.88 billion people worldwide remain at risk of insufficient iodine intake [4]. Iodine deficiency is the major cause of preventable mental retardation/ brain damage in the world [1]. About 38 million newborns in developing countries every year to remain unprotected from the lifelong consequences of brain damage associated with IDDs [5]. Iodine deficiency alone can lower mean Intellectual Quotient (IQ) scores by 13.5 points [6] and a mild iodine deficiency can cause a significant loss of learning ability [7]. Ethiopia is a country with a high prevalence of IDDs. Goiter prevalence rates vary significantly from region to region in Ethiopia and in certain areas the prevalence rate may be as high as 71% [8]. Total goiter prevalence in Ethiopia was 35.8% in which 24.3 and 11.5% were palpable and visible goiter respectively. Goiter prevalence in the Tigray regional state were greater than 30% an indication of severe iodine deficiency [9].

The global prevention and control of IDDs recommends Universal Salt Iodization (USI) to a level of 30–100 PPM with any iodine compounds [10] as the most cost effective development efforts contributing to economic, social development and sustainable long term first line public health measure [11–14]. Characteristics of families not using iodized salt need to be known to expand coverage of iodized salt [15]. Households in low socioeconomic categories comprise a vulnerable subset of the population at risk of being exposed to under-iodized salt [12].

Even though the Ethiopian Ministry of Health (MOH) launched USI in Ethiopia in 1995 for long term sustainability of IDD prevention and control program [3]. Awareness of IDD problems and the benefits of iodized salt by the Ethiopian public are low [16]. To enhance iodized salt utilization level, consistent monitoring of iodine in salt at production, storage, sale and consumption level; and prevention of sale of non-iodized salt are key components of salt iodization programs [17]. Iodine is a sensitive mineral and losses might occur during improper practice [12]. Hence Quality and Standards Authority of Ethiopia, has set the iodine level to be 60–80 PPM as potassium iodate (KIO₃) after making allowance for losses during storage and distribution. The presence of iodized salt alone is not enough, but appropriate practice at household level is mandatory towards meeting the goal of IDDs elimination [17].

Different studies showed households using adequately iodized salt at the household level were low in Tigray region and other regions of Ethiopia [18–20]. None of these studies did not addressed on factors affecting to proper iodized salt utilization at household level. Likewise, there were limited studies done on iodized salt utilization at both national and regional household levels. Therefore, the main aims of this study were to determine the iodine concentration in the collected salt samples, adequately iodized salt consumption coverage and identify factors affecting on proper iodized salt utilization among the households of Ahferom district, North Ethiopia.

The main aim of this study was to assess adequately iodized salt coverage, iodine concentration in salt and factors affecting proper iodized salt utilization among the households of Ahferom District, North Ethiopia. This in-depth community-based study revealed that 52.83% of the respondents have self-reported as they use adequately iodized salt, however, only 17.5% of the households were using adequately iodized salt when tested using an iodometric titration technique. The kappa agreement of iodometric titration test and validity of predicting adequately iodized salt by using perceived self report was poor. This indicates either there was a problem in identification of iodized salt during the purchasing or there might be a loss of iodine more than expected during storage and/ or transportation of the iodized salt in the whole sellers, shops and others where salt was sold.

The coverage of adequately iodized salt among the households based on the test was 17.5%. This was much farther to the WHO target of 90% coverage [12]. This coverage was also very low when compared to the studies conducted in India in 2005 and to the study conducted in South Africa in 2001 which had iodized salt utilization 65 and 63% respectively [6, 12]. It was four folds lower if it was compared with the study conducted in Ghana in Bia district in 2011 [24]. It is also slightly lower as compared to the National studies conducted in 2005 (20% coverage) in Ethiopia [25]. And it was better compared to the EDHS 2000 (10% coverage) report with children under 5 years’ households of Tigray region [18]. However, it was lower coverage compared as per EDHS 2005 (25%) and 2011 (22.3%) report in Tigray but similar to Ethiopia as per EDHS 2011 (15.4%) [19, 20].

Similarly, this coverage was very low (greater than fivefold lower) as compared to the study conducted in 2002 in Shebe town, southwestern Ethiopia, which showed 92.7% of the household had used iodized salt [10]. The finding of this study was also lower than the study done in Gondar North west Ethiopia in 2012, which was 28.9% coverage [26]. Another study conducted in Bensa district Sidama, Ethiopia indicated adequately iodized salt (≥15 ppm) was found in 45.2% rural and 65.0% urban households [27].

The reason why the coverage of households using iodized salt in this current study was lower than the global and regional levels might be due to the influence of low national coverage or distributional barriers to different parts of the country as well as poor community awareness on prevention of IDDs and the benefits of iodized salt [16]. Reasons have been given for the failure of most developing countries to achieve 90% iodized salt utilization among the households. These were political factors and logistical problems in the production and distribution of iodized salt [25]. The other reason might be poor enforcement practices by regulatory agencies, infrequent to no monitoring and evaluation. Just because a certain target is achieved in one evaluation by no means assures that future results will be consistent. Hence continual program monitoring and cooperation of regulatory enforcement agencies are essential to ensuring the adequacy of iodine fortification levels. On the other hand, Ethiopia is not major salt producing country [28] and even there might be inadequacies in regulation of the fortified salt produced within the country. This could have an influence to decrease coverage of adequately iodized dietary salt at household level.

The most effective way to control, IDD is through salt iodization, WHO, UNICEF, and ICCIDD recommended that iodine should be added to salt a concentration of 20–40 PPM depending on salt intake [29]. About 17.5% of the salt sample taken from the households in this study had iodine concentration above 15 PPM. This was fourfold lower even if it was compared to to the iodine concentration above 25 PPM, to the study that was conducted in Bia district, Ghana in 2011 [24]. When this study was also compared to the study conducted in Shebe town, Western Ethiopia [10]; the concentration of iodine >15PPM were even lower than the concentrations between 60 PPM- 80PPM. This shows that there was a huge gap of iodized salt utilization in this study area. These differences might be due to poor regulation activities against non iodized salt in the market, where salt was sold.

According to the Quality and Standards Authority of Ethiopia, has set the iodine level shouldn’t exceed above 80 PPM as potassium iodate (KIO₃) after making allowance for losses of iodine during storage and distribution [3]. However, there were salt samples collected from 9 households that had an iodine concentration above 80 ppm in this study. This shows that there might be iodized salt producers not having any inspection procedures by the Authorities.

Proper utilization of iodized salt among the households was 18% less likely lower as family size increase by one other factors held constant. This OR could be as low as 0.67 and as high as 0.92 at 95% CI. Even though there were no other studies that support for this finding, as the family size increase economic constrain might increase, which leads to reduce in the purchasing of iodized salt to the household members since it is slightly higher in its cost compared to the non iodized salt in the market.

The odds of proper iodized salt utilization among households resided in urban was 2.83 times higher than households that had resided in rural other factors held constant. The OR ranges from 1.48 to 5.40 at 95% CI. There were no previous studies that show the strength of association with regard household residency. However EDHS 2011 described that urban household is more likely to use iodized salt than rural households [20]. This difference might be urban residents might have better access to mass media that motivates them to utilize iodized salt properly. In addition to that there were higher in education status in urban compared to the rural food caterers which can have better knowledge and practice to iodized salt utilization.

Households that have availability of iodized salt have utilized iodized salt properly 3.90 times the odds of those households which didn’t have availability to iodize salt other factors held constant. The 95% CI was from 1.74 to 8.70. This finding in line with most salt produced in Ethiopia was non iodized, iodized salt was estimated to be less than 5% in 2009 [28]. The main reasons for such insufficient accessibility might be many and various, both at the level of sellers and consumers. Various demographic, societal and economic factors may have influences on iodized salt utilization practice [30]. In many cases it has been observed that awareness of the use of adequately iodized salt as a preventive measure against IDD exists but the access to iodized salt is limited. In most cases the restriction to iodized salt utilization was because of iodized salt was not available [25].

The odds of proper iodized salt utilization among households that can afford the cost of iodized salt was 3.22 times higher than households that couldn’t afford the cost of iodized salt all other things being equal. The estimated 95% CI was from 1.41 to 7.34. There are descriptives that have aligned with this study. Socio economics factors are the most contributing factor to IDD because least developed countries are more affected [31]. Study in Ethiopian households revealed those highest wealth Quintiles were twice as likely to use iodized salt as households in the lowest two wealth Quintiles. Those with highest wealth quintile might have a capacity to afford iodized salt as compared to that lowest quintile. This restriction of iodized salt was sometimes due to affordability [25]. There were evidences supported for this finding by researches conducted in low and middle income countries [32]. It have Confirmed better practices of iodized salt has a relationship with the price of the salt [33]. A similar evidences have reported that excess cost of iodized salt might be a barrier in preventing IDDs. This forces people not to purchase and use the iodized salt [34].

This study concluded that the coverage of adequately iodized salt among the households was low. Most of the households were using below adequate level of iodine concentration in the salt. There were households salt samples iodized above the national standard. Family size, affordability of iodized salt, availability of iodized salt in the market and household residency were the main predictors to proper iodized salt utilization. This study points importance of routine monitoring and evaluation of USI. To prevent IDDs and enhance USI utilization effective inspection and regulatory measures should be taken at the manufacturers, whole sellers and retailers to prevent the production and distribution of under/ over iodized salt in the market.