Malnutrition is not always visible to the naked eye. A child could look healthy but still suffer from massive nutrient deficiencies. It is called hidden hunger — a chronic deficiency in micronutrients — and affects a large part of Sierra Leone’s population.
The IAEA and the Food and Agriculture Organization of the United Nations (FAO) are helping to ensure that Sierra Leonians — particularly young children, who are the most affected — get the essential vitamins and minerals they need. Using nuclear technology, scientists are developing new nutrient-rich crops that accumulate higher contents of iron and other micronutrients.
“Although food availability is normally the primary food security concern, food quality is just as important,” said Joseph Sherman-Kamara, Acting Deputy Vice-Chancellor at Njala University and Head of the Postharvest Food and Bioprocess Engineering Laboratory. “With nuclear technology, we can develop new varieties of major food crops that have improved nutritional contents and health benefits.”
Hidden hunger affects an estimated two billion people in the world. Of the 20 countries with the highest Hidden Hunger Index scores, Sierra Leone ranks sixth. In 2018, Sierra Leone had the highest child mortality in the world, estimated at 110 out of 1000 live births, according to UNICEF. Almost half of these deaths were linked to malnutrition.
“Chronic cases of childhood micro-nutrient malnutrition, including lack of vitamin A and minerals such as iron, tend to persist from childhood to adulthood, with significant consequences on national health and productivity,” said Isaac Kofi Bimpong, a plant geneticist at the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture.
Two IAEA fellows in Njala University sort plant seeds that were irradiated at the IAEA’s Seibersdorf laboratories in Austria. (Photo: L. Gil/IAEA)
Various IAEA technical cooperation projects have in the past years helped Sierra Leone improve the nutrient content in crops through the development of new plant varieties (see The Science). Most projects have focused on rice and cassava as priority food crops to develop new varieties with improved nutritional quality. The Joint FAO/IAEA Division, through its own specialists and international experts, has been training scientists in both plant mutation breeding and nutrient analysis.
In 2017, scientists from Sierra Leone used nuclear techniques to irradiate local varieties of rice and cassava at the laboratories run by the Joint FAO/IAEA Division in Seibersdorf near Vienna, Austria, to select new lines with improved traits. So far, they have developed over 2 000 cassava and more than 3 000 rice new lines, with the aim of improving nutritional contents, along with other beneficial traits. Further selection will be done using advanced biochemical screening techniques (see The Science) at Njala University’s newly-established analytical lab in the Department of Agricultural and Biosystems Engineering.
In the new lab, using equipment provided by the IAEA, scientists will be able to measure the amount of nutrients and minerals present in the improved rice and cassava lines and other food products to assess their nutritional quality. The lab will also be able to monitor the presence of potential toxinsand other contaminants in food crops.
Three scientists — two at the University of Njala and one at the Sierra Leone Standards Bureau — have been trained on the analysis of metals and mycotoxins, among other contaminants. Through the Joint FAO/IAEA Division, international experts will further train the team in the use of the new equipment, addressing the country’s need to systematically monitor food and environmental samples for food safety.
“The long-term goal is to generate nutritionally enhanced varieties of rice and cassava that will lead to new nutritionally enhanced products with more carotene in cassava, increased protein in maize, and more vitamins and minerals in rice,” Sherman-Kamara said. “And to combine this into a food package that can blend with the rest of the food that families eat. That’s the end game.”
In related research, geneticists at Njala University are using mutation breeding to develop and select rice varieties that have the capacity to tolerate high levels of iron and other heavy metals. Iron from mining activities is increasing in soils where crops grow. While iron is a good nutrient in food, in high quantities it can be toxic to both humans and plants.
“Excess iron present in soil decapitates the tips of the roots, which are the plant’s mouth essentially,” said Alieu Mohamed Bah, Crop Scientist and Senior Lecturer at Njala University in central Sierra Leone.
Scientists have developed more than 3 000 rice lines, looking for more nutritional content and other improved traits. (Photo: L. Gil/IAEA)
Plant mutation breeding
Plant mutation breeding is the process of exposing plant seeds, cuttings or tissue-culture material to radiation, such as gamma rays, and then planting the seed or cultivating the irradiated material in a sterile rooting medium, which generates a plantlet. The individual plants are then multiplied and examined for new and useful traits. Once the genetic changes giving rise to new traits have been identified, molecular marker-assisted breeding can be used to accelerate breeding of new varieties with desired traits.
Plant mutation breeding does not involve gene modification, but rather uses a plant’s own genetic resources and mimics the natural process of spontaneous mutation: the motor of evolution. By using radiation, scientists can significantly enhance the genetic diversity necessary to develop novel and improved varieties.
To facilitate the selection of plants with improved nutritional contents, and to assess the safety and quality of food products, sound analytical laboratories are required. These enable the measurement of nutritional contents in plants and grain, while also determining unacceptable levels of toxic metals and contaminants in food.
Scientists use atomic absorption spectrometers to detect the wavelengths of light transmitted by atoms in a sample.
All atoms have their own way of absorbing wavelengths of energy. Each wavelength of energy corresponds to a distinct element. By knowing which wavelength corresponds to which element, scientists can precisely and instantly determine the nature and quantity of specific elements in the sample.