Iodine Deficiency in Senegal: Impact on Sustainable Human Development and Determining Factors

Abstract

Introduction: Despite being a relatively stable democracy experiencing about 6% economic growth over the last five years (2014 to 2018), Senegal still faces many challenges including a high poverty rate with about 38% of the country’s population below the poverty line (US$1.90, PPP), low literacy rate with 51.9 % illiterate (World Bank Group, 2019), and large inequity as expressed by its Gini index that has evolved very slightly from in 41.20 from 2001 to 40.3 in 2011 (World Bank Group, 2019). The reduction of malnutrition that includes iodine deficiency is amongst the priorities identified for helping the country to achieve quality human capital, social protection and sustainable development (Cellule de lutte contre la Malnutrition, 2017).

Iodine is an essential constituent of the Thyroid hormones and has been recognized to play an important role in nutrition through the role of thyroid hormones in the growth and development of both humans and animals (Basil S, Potter, & Dulberg, 1990).

In 1991, the United Nations General Assembly set a global public health goal of virtually eliminating iodine deficiency that is recognized as the world’s most preventable cause of mental impairment. Subsequently, in January 1994 the World Health Organization (WHO) and UNICEF (UNICEF, 1994) recommended universal salt iodization, first introduced in 1922, to ensure adequate intake of iodine that cannot be synthetized by the body (World Health Organization, 2007). The level of populations’ intelligence is known to play a key role in nations’ economic development, democracy and social governance that are in turn critical elements of global and sustainable human development (Sen, 1999).

Senegal needs high quality human capital in order to fulfill its ambition for becoming an emerging economy by 2035. Therefore, the country’s salt iodization program should be efficiently implemented to ensure that at least 90% of households consume salt iodized to at least 15ppm iodine so the population–especially women of reproductive age–meet their daily required iodine intake.

Methodology: A case study design was used to assess the iodine nutrition status of the population of Senegal and analyze its most significant determinants 20 years after the country adopted its salt iodization program as the main strategy for preventing Iodine Deficiency Disorders (IDD) and further estimate the human cost of current levels of iodine deficiency in women of reproductive age. Senegal was also compared with a few Sub-Saharan African countries characterized by a similar salt industry (Ghana and Tanzania), importing salt from Senegal, and from outside Africa (Uzbekistan). Secondary data from a strata-level representative cross-sectional cluster survey from 1,968 households surveyed in 2014 were analyzed. The data collected and analyzed include socio-cultural and economic information, household food consumption including consumption of cooking bouillons and cubes as well as salt. Between 10–50 g salt samples were collected from each selected household for laboratory analysis. Salt samples were collected from 1,764 households. Spot urine samples were also collected from 1,805 non-pregnant women for the measurement of urinary iodine concentrations.

Key Results: Key results show that after over twenty years of implementation of national salt iodization program, Senegal is still affected by iodine deficiency (national level median urinary iodine concentration of women of reproductive age at 94.9 µg/l), with rural settlement (median Urinary Iodine Concentration (UIC): 75.68 µg/l) and high poverty index groups (median UIC: 83.53 µg/l) as the main drivers. These national level figures also reveal an inequity in iodine nutrition status with urban and low poverty groups enjoying median urinary iodine concentration of respectively 115.99 µg/l and 116.58 µg/l e.g. above the WHO’s 100 µg/l cut-off; while the rural and high poverty index population groups have insufficient nutrition iodine status with 75.68 µg/l and 83.53 µg/ median UIC respectively . This clustered iodine deficiency leads to about 1.5 to 1.7 million cumulative Intelligence Quotient points loss that in turn can lead to the country’s reduced economic growth and affect its sustainable human development using the estimates that 1 Standard deviation (SD) increase in intelligence leads to long run economic growth increases by 1.17 points (Salahodjaev, 2015) and one point increase in IQ, contributes to 0.1 points decrease in corruption (Potrafke, 2012).

Despite salt iodization being implemented in the country over nearly twenty years with active contributions from international development partners, about 62.84% of the households are still not using salt iodized at the required ≥ 15ppm (World Health Organization, 2014). This is particularly worrying in rural areas, households with no members having achieved 5 years of schooling, and the poorest household groups where the mean iodine content in the salt they consume is below the 15ppm minimum iodine level required to meet the Recommended Nutrient Intake (RNI). Cooking bouillons mainly made of salt that is supposed to be iodized, are highly and regularly consumed by households (> 90% daily consumed). The cooking bouillons used in Senegal contain sodium (20.8% to 26.1%) coming mainly from salt (91.5–99.6%) (Rebecca, et al., 2015) and provide 1.4 to 24.4 ppm iodine per serving (Rebecca, et al., 2015).

Disparities in nutrition iodine status according to household settlement and wealth categories have also been observed in countries like Ghana, Tanzania and Burkina Faso as well as in Uzbekistan despite differences in economic situations. However, equitable access to adequate intakes of iodine through adequately iodized salt have been observed in countries like Kenya (Bukania, et al., 2019) and Ethiopia (Ethiopia Public Health Institute, 2018) where the salt iodization is processed in a limited number of large central iodization facilities.

The impact of this iodine deficiency in Senegal will contribute to maintain or exacerbate the inadequate human development status in Senegal. The country is experiencing a low level of schooling, particularly in rural areas with only 65.9% of the surveyed households at the national level and 22.9% in rural areas having at least one member who completed 5 years of education. Poverty levels are still widely affecting the country with respectively 68.8% rural households and 31.2% urban households belonging to the high poverty index group.

Conclusions: Addressing iodine deficiency disorders (IDD), known as the most preventable cause of brain impairment, should be considered as an essential investment in global development; especially in countries like Senegal where there are huge needs for improvement in human capital. The salt iodization intervention that has demonstrated it effectiveness on the reduction of the iodine deficiency since early the 1920s (West, Jooste, & Pandav, 2004) is facing several socio-political constraints in low income salt producing developing countries like Senegal. The salt production sector in Senegal involves large numbers of small salt producers that are estimated to over 13,000 for whom salt production is an essential livelihood activity. This pushes local political and religious leaders to put pressures on the government enforcement teams when they should act against small salt producers and distributors that are not complying to national salt iodization standards. These challenges are exacerbated by a large informal national food distribution system that drives iodine deficiency in the country, especially in the rural areas. The government of Senegal should bring significant changes on its salt iodization program paradigm to address the supply and regulatory issues that limit its efficiency. In addition, recommendations are made for a more consolidated salt iodization processing industry where the raw salt is supplied to automated salt iodization processing factories by the small producers to sustain and consolidate their livelihood salt production activities. Thus, Senegal’s entire salt iodization will be centrally processed in factories adequately equipped to perform efficient internal quality assurance and where government enforcement teams can undertake efficient inspections as recommended for effective food fortification program (World Health Organization and Food and Agriculture Organization of the United Nations, 2006).

Further research needs to be conducted to:

• Assess the impact of sub-optimal iodine status in the outcomes of the investment made by Senegal’s government and its development partners, to improve the education sector on the one hand and achieve the 2035 Plan for an Emerging Senegal (PSE) objectives for a fair society in a rule of law state where wealth, jobs and social inclusion amongst others are created.

• Assess the economic viability and social impact on local communities of a consolidated salt iodization processing industry in Senegal.

• Estimate the impact of the iodine deficiency status on Senegal Disability Adjusted Life Years (DALYs).