Six sub-sessions
Speakers and presentations
Richmond Aryeetey
‘Because of Galamsey, there isn’t food in the town’: A photo story of small-scale mining and food security in Ghana
Recording
Julien Zahouli
Impacts of agricultural land-use change on the ecology of Aedes arbovirus vectors in yellow fever and dengue foci in palm plantations in Côte d’Ivoire
Recording
Beliyou Haile, International Food Policy Reseach Institute (IFPRI)
What are the nutritional effects of climatic and weather shocks? Evidence from Sub-Saharan Africa
Recording
Hassan Eini-Zinab, Department of Community Nutrition, Shahid Beheshti Medical University
Healthy diet: A step toward a sustainable diet by reducing water footprint
Recording
Genevieve Tchigossou, University of Abomey-Calavi
An additional approach for controlling malaria in rural agricultural settings of Malanville in the northern Benin: Minimal tillage and intermittent flooding is likely to reduce Anopheles breeding sites and densities in rice fiel
Recording
Felix Pensulo Phiri, University of Nottingham
Quantifying selenium status in Malawian population
Recording
Q&A
Recording
‘Because of Galamsey, there isn’t food in the town’: A photo story of small-scale mining and food security in Ghana
Richmond Aryeetey
Introduction
Small scale mining, popularly known as ‘galamsey’ in Ghana, has come under political and media scrutiny since 2017, due to its known devastating effects, including land degradation, destruction of forests, and pollution of water bodies. However, little is known about the linkages between galamsey and food systems in mining communities. The current study was designed to describe community perceptions and experiences of galamsey and its effects on food security and livelihoods.
Methods
This cross-sectional study was carried out in the East Akyem Municipality (EAM) of Ghana between December 2017 and February 2018 using multiple data collection techniques: photovoice, photo exhibition, in-depth interviews, and a survey. Thirty male and female respondents comprising of adults and adolescents were selected purposively from three communities in EAM to take up to 15 photos that ‘describe the food security situation in their community and how this is shaped by small scale mining.’ All respondents were given training and supplied with a mobile phone (iTel 17100) with a camera feature for taking photos. Three to four days after the training, respondents returned the photos and in an in-depth interview and discussed the motivation for taking five photos of their choice. The photovoice data was validated with a photo exhibition, which provided an additional opportunity to learn about community responses to food security in the Municipality. In addition to the photovoice data collection, 300 respondents selected using cluster sampling from 10 communities in the Municipality completed an interviewer-administered survey. The data was analysed based on a food security framework comprising of food availability, access, and utilization.
Findings and Interpretations
Several and diverse themes emerged from the evidence indicating community perception of how galamsey affects food production. The themes included destruction of land fertility, reduced crop yield, limiting water supply for farming, limited physical accessibility to farms, as well as ruining aquaculture systems. Galamsey was also linked with limited food access through its creation of food scarcity which makes food more expensive at the community level. As a result, there was a report of community members needing to travel outside EAM to purchase food from nearby communities. This scarcity occurs within the context of not having a food market in the Municipality. On the other hand, galamsey was credited with creation of jobs for women who sell prepared food to the miners. Finally, galamsey was linked with poor food safety as a result of toxic mercury entering the food system and creating diseases. In the 10 communities surveyed, 66 percent of households reported insufficient food intake.
Conclusions
Ghanaian communities with heavy mining activities consider small scale mining a significant threat to food security. The implications of the above findings are discussed in this presentation, focusing on the need to ensure that food security is not compromised by mining activities. Specific attention is given to how degraded mining sites could be reclaimed for smallholder sustainable agriculture for improved food and nutrition security. The presentation also discusses how the positive aspects of galamsey could be leveraged to counteract its negative consequences.
Impacts of agricultural land-use change on the ecology of Aedes arbovirus vectors in yellow fever and dengue foci in palm plantations in Côte d’Ivoire
Julien Zahouli
Introduction
Aedes mosquito-transmitted arboviruses have (re)emerged from their sylvatic reservoirs of Africa and the Americas under terrestrial-ecosystem anthropization forces and caused many diseases worldwide. As the resurgence and geographic expansion of arboviral diseases and ecology of Aedes vectors can alter under human-driven landscape alteration, identifying priority areas among intensive agricultural areas for integrated vector management (IVM) is crucial for public health. We explored the impacts of agricultural land-use change on the ecology of Aedes mosquitoes along a gradient of anthropogenic disturbance in large industrial oil palm plantation areas within yellow fever and dengue foci in Côte d’Ivoire.
Methods
Between January and October 2014, Aedes mosquitoes were sampled as eggs, larvae, pupae and adults among four major land-covers (rainforests, polycultures, oil palm monocultures, and rural housing areas) using standard procedures (bamboo-ovitraps, metallic-ovitraps, larval surveys, and human-baited double-net trap methods). Specimens were identified at species level. A total of 28,276 Aedes specimens belonging to 11 species (Ae. aegypti, Ae. africanus, Ae. dendrophilus, Ae. fraseri, Ae. furcifer, Ae. lilii, Ae. luteocephalus, Ae. metallicus, Ae. opok, Ae. palpalis, and Ae. vittatus) were collected. No Aedes-positive microhabitat and only four specimens of Ae. aegypti were found in oil palm monocultures. The highest abundance of Aedes mosquitoes (60.9%) was found in polycultures, while the highest species richness (11 species) was observed in rainforests. Ae. aegypti was the predominant Aedes species, and exhibited high anthropophilic behavior inflicting 93.0 percent of total biting to humans. The biting rate of Aedes mosquitoes was 34.6 and 7.2-fold higher in polycultures and rural housing areas, respectively, compared to rainforests. Ae. aegypti, Ae. dendrophilus, and Ae. vittatus species bit humans in polycultures and rural housing areas, with respective biting rates of 21.48 and 4.48 females/person/day. Unexpectedly, all three species were also feeding during darkness. Aedes females showed bimodal daily feeding cycles with peaks at around 8:00 a.m. and 5:00 p.m. Host-seeking activities were interrupted between 11:00 a.m. and 2:00 p.m. in rural housing areas, while no such interruption was observed in polycultures. The rainforest-dwelling Aedes species displayed little preference to feed on humans.
Conclusions
In Côte d’Ivoire, the agricultural land-use/land-cover changes due to the transformation of rainforests into vast industrial oil palm monocultures influence the ecology (abundance, distribution, and host-seeking behavior) of anthropophagic and non-anthropophagic Aedes resulting in the migration of arbovirus vectors towards the polyculture and rural housing areas. As result, humans (villagers and farmers) are increasingly exposed to Aedes bites and yellow fever and dengue transmission virus risk around their homes and farming plots. Hence, the polyculture and the rural housing ecotopes represent priority areas for vector control and surveillance. In oil palm-planted areas, arboviral disease control strategy should encompass integrated vector management (IVM), including landscape ecology and epidemiology and ecotope-based vector control, agricultural practices and rainforest management.
What are the nutritional effects of climatic and weather shocks? Evidence from Sub-Saharan Africa
Beliyou Haile, IFPRI
Introduction
There is a growing literature on the linkages between climatic shocks and nutrition outcomes, often motivated by agricultural mechanisms but there is limited work on disentangling possible mechanisms. Existing studies involving young children do not adequately account for the dynamics of growth faltering and failure to analyze nutritional effects of climatic shocks for different cohorts of kids can produce biased results. This study examines the nutritional effects of climatic shocks in sub-Saharan Africa (SSA) by exploring possible pathways (through yield and spread of diseases) and possible growth faltering.
Methods
The empirical analysis combines data from the following sources. Nutritional outcomes of under-five children and adult women as well as other household-level socioeconomic outcomes for 24 countries come from the Demographic and Health Surveys (DHS). A time series of precipitation and temperature data come from the Climate Research Time Series Grid Version 3.23 at the University of East Anglia. Gridded landscape-level data on agro-climatic, biophysical, and economic factors (e.g., elevation and market access) is CELL5M. Different thresholds of weather conditions are identified by major farming systems based on documented responses of yields and diseases to changes in temperature and rainfall. Shocks are defined by calendar year, growing season, and timing of the child’s exposure (in utero or afterwards). A flexible non-parametric bin approach is employed to estimate the effects of precipitation and temperature shocks on undernutrition. Heterogeneous effects are examined along several dimensions (e.g., past expose to shocks, farming systems, household’s socioeconomic conditions).
Findings and Interpretations
Preliminary results show both drought and excess rain during the growing season increase the incidence of under-five wasting in general and wasting among 25-59 months old children. Exposure to repeated drought condition also has a significant positive effect on stunting among older cohorts. While drought condition negatively affects seed germination, plant growth, yields, and livestock, excess rainfall may lead to surface runoff and soil waterlogging - especially in already degraded areas-, cause damages to crops and livestock, worsen phyto-pathological conditions, and cause overall logistical challenges. A higher incidence of wasting has previously been linked with (repeated) exposure to flooding. Above average temperature in the preceding growing season reduces child stunting in highland mixed and roots and tubers farming systems, relative to maize mixed system. Findings are in line with model-based predictions where a warming trend in high- and mid- altitude areas could help extend the growing seasons, potentially enabling more productive agricultural seasons.
Conclusions
Climatic and weather shocks are important determinants of nutrition and health outcomes in sub-Saharan Africa, given the region’s reliance on rainfed agriculture and projected climatic changes. While the link between weather shocks and agricultural productivity is relatively clearer, the linkage between weather shocks and nutrition is more complex and operates through multiple channels. As such, establishing causal links between weather variability and nutrition is challenging. Additional challenge relates to ensuring one does adequately capture the spatial and temporal climatic variation relevant to the farming systems and livelihood strategies under consideration. Preliminary result from this study indeed shows significant variation in the effects of weather shocks on undernutrition, including by farming systems, age-cohort, and intensity of previous exposure.
Healthy diet: A step toward a sustainable diet by reducing water footprint
Hassan Eini-Zinab, Department of Community Nutrition, Shahid Beheshti Medical University
Introduction
Water shortage is an important crisis humans are facing currently. The problem is more severe in some parts of the world. The average rainfall in Iran is less than a third of the global average. The declining water resources are best seen by the almost eradication of Urmia Lake. Building dams and diverting water resources for human and agricultural use, along with overuse of surface water seem to be the main contributors. Changing the population's eating pattern toward a more healthy diet can help reduce water use. This paper aims to assess different scenarios that reduce water use by following healthy diet recommendations. In this study, the food frequency questionnaire was used to assess usual food intake of a 723-individual sample from Urmia, capital city of West-Azerbaijan province in Iran. The water footprint method was applied to calculate water use for production of food items (168 items). A linear programming technique was used to find a healthy diet with a low water footprint in three scenarios. The objectives and changing variables for all three scenarios were minimizing the blue water use, which refers to consumption of surface and ground water resources along the supply chain of a product, and intake of food items, respectively. To consider dietary habits, the changing variables were constrained to vary between first and third quartiles of usual intake. Additionally, for the first scenario, the model-produced diet, should have energy intake equal to that of usual intake. In the second scenario, in addition to energy constraint of the earlier scenario, the changing variables are constrained to follow the advised serving size of food groups by the Iranian food dietary pyramid. In addition to the constraints of the second scenario, Dietary Reference Intake for macronutrients, micronutrients were considered as constraints in the third scenario. The energy intake constraint was relaxed in this scenario.
Methods
The average energy intake of the sample was 2920Kcal. The highest proportion of calories was supplied by “bread-cereal-rice-pasta” (39%). The lowest contribution belongs to the “fruit” and “vegetables” groups (8%). The amount of water to supply daily diet for a person was 4.11m3. In the first scenario, the share of “bread-cereal-rice-pasta,” “vegetables,” and “fruit” in supplying daily energy increased by 44, 58, and 4 percent, respectively. The contribution of “milk-yogurt-cheese” (92%), “meat-poultry-fish-drybeans-eggs-nuts” (31%), and “fats-oils-sweets” (28%) decreased. The lowest amount of water needed at this scenario was 1.78m3, a 57 percent decline. For second scenario, compared with real diet, the energy share of “bread-cereal-rice-pasta,” “meat-poultry-fish-drybeans-eggs-nuts,” and “fats-oils-sweets” have decreased by 28, 21, and 0.1 percent, respectively. Furthermore, the contribution of “vegetable” (86%), “fruit” (21%), and “milk-yogurt-cheese” (40%) have increased. The amount of water needed to supply one person for a day at this scenario was 2.17m3, a decline of 47 percent from the real. For the third scenario, the share of “bread-cereal-rice-pasta,” “meat-poultry-fish-drybeans-eggs-nuts,” and “vegetable” in providing average daily energy have decreased by 37, 28, and 45 percent, respectively, compared with real diet. Likewise, the contribution of “fats-oils-sweets” (8%), “fruit” (68%), and “milk-yogurt-cheese” (99%) have increased. The amount of water to supply this diet was 2.1m3, a 49 percent decline.
Conclusions
A healthy diet with a greater proportion of fruits and dairy instead of a diet with high consumption of “meat-fish-poultry-eggs” and “bread-cereal-rice-pasta” can supply all recommended dietary allowances while reducing water use. The decline in water consumption in the recommended diet of this study is mainly due to a decrease in the share of animal products. Meat-based diets have a larger water footprint compared with vegetarian diets. A high proportion of water footprint for animal products is due to their consumption of feed which accounts for 98 percent of the total water footprint. Although dairy products have a higher water footprint as well, their contribution increased in this study’s recommended diet. Dairy products are rich in a large variety of essential nutrients such as minerals, vitamins, and easily digestible proteins with balanced amino acid profiles which are important to support overall body function
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An additional approach for controlling malaria in rural agricultural settings of Malanville in the northern Benin: Minimal tillage and intermittent flooding is likely to reduce Anopheles breeding sites and densities in rice fiel
Genevieve Tchigossou, University of Abomey-Calavi
Introduction
Recent work in rice-growing areas in Mali has revealed the link between poor agricultural practices and the proliferation of malaria vectors. In this context we proposed to reduce the density of Anopheles in rice growing areas using two innovative approaches, namely, minimal tillage and intermittent irrigation. The aim of our study is to confirm that minimum tillage and intermittent irrigation are likely to reduce the density of Anopheles populations in the Malanville rice area.
Methods
Through direct observations of rice plots, group discussions, and individual interviews, the different tools and types of tillage and irrigation used by farmers were identified. Direct observations were conducted by small groups of researchers and producers. Group and individual discussions involved both men and women in order to deepen the information gathered during the direct observations, to get farmers' perceptions on the link between rice production and mosquito proliferation and their perceptions on the management of malaria. Discussions with health actors were also carried out to collect information on periods of high and low incidences of malaria corresponding to rice cultivation periods. Farmer field training courses were organized to identify, through a participatory approach, agricultural practices which could reduce mosquito density in rice-growing areas. Finally, mosquito larvae were collected in the test and control plots and quantified according to the rice developmental stages (transplantation, tillering, and maturation). The data were analyzed by calculating the relative abundance of larvae in control and test plots and by comparing the larval density between plots.
Findings and Interpretations
Direct observations revealed that farmers use the hoe, plough, and tiller for the tillage. The deep tillage system is practiced by most farmers. The irrigation method known and used by farmers is permanent irrigation with Niger River water and boreholes. Through the individual interviews, several farmers recognized that rice cultivation is a source of mosquito proliferation and the stagnant waters around houses also favor the proliferation of mosquitoes. Insecticide treated nets is the main method used by farmers to prevent malaria. According to the actors of the sanitary system, it emerges that the cases of malaria are more detected during the season of rice production. Farmer field school trainings enabled farmers to link rice cultivation with mosquito proliferation and to understand that minimal tillage and intermittent irrigation are able to reduce the development of mosquito larvae while maintaining agricultural yield. Minimal tillage and intermittent irrigation reduced larval density by 8.83 times during transplantation, 3.88 times during tillering, and 4.75 times during maturation. During the three phenological stages of rice, the system of minimal tillage and intermittent irrigation significantly reduced the density of mosquito larvae (p = 0.0001) compared to the deep tillage and permanent irrigation system.
Conclusions
The results from our study confirm a strong proliferation of mosquitoes in the rice fields. It shows that in a rice-growing environment, the system of deep tillage and permanent irrigation maintains a high density of mosquitoes throughout the entire rice development cycle. This study establishes also the capacity of minimal tillage and intermittent irrigation to significantly reduce the densities of malaria vectors in rice-growing areas. However, the adoption of these technologies requires a strong awareness of farmers.
Quantifying selenium status in Malawian population
Felix Pensulo Phiri, University of Nottingham
Introduction
Selenium (Se) is an essential micronutrient with many roles in human health. Deficiency of Se decreases selenoprotein expression and activity, thereby compromising immune function, thyroid function and cognitive development, and increasing risks from non-communicable diseases. The prevalence of Se deficiency is not known in many countries with particular knowledge gaps in sub-Saharan Africa. High risks of Se deficiency were predicted in Malawi based on widespread inadequate dietary Se sources and a high prevalence of Se deficiency in small cross-sectional studies. We quantified nutritional Se status and deficiency at a national scale as part of the Malawi Micronutrient Survey (MNS) 2016.
Methods
The survey comprised a nationally representative sample of preschool children (PSC), school-aged children (SAC), women of reproductive age (WRA) and adult men. The scope of the MNS, including details of the sampling design, ethics, informed consent, and individual confidentiality procedures, are described in the survey report. Plasma Se concentrations were determined using inductively coupled plasma-mass spectrometry (ICP-MS). In total, data were obtained for 2761 individuals from 1233 households, located in 102 clusters, 84 and 18 of which were located in rural and urban areas, respectively. Data were analyzed using a linear mixed model to quantify long- and short-range sources of variation linked to Se status. Based on output from this model, the probabilities of plasma Se concentration of <84.9 ng/mL and <64.8 ng/mL in adults were computed. These thresholds are linked to optimal activities of the selenoproteins glutathione peroxidase 3 (GPx3) and iodothyronine deiodinase (IDI), respectively. These probabilities were presented as maps, using a verbal scale to visualize the probability that plasma Se falls below the thresholds of interest.
Findings and Interpretations
Across all demographic groups, the mean and median plasma Se concentration was 73.2 ng/mL and 68.2 ng/mL, respectively. Deficiency was widespread: for example, 62 percent of WRA had plasma Se concentration below the threshold for optimal GPx3 activity and 30 percent had plasma Se concentration below the threshold for optimal IDI activity. There was strong spatial structure to the data with environmental factors such as soil type and proximity to Lake Malawi strongly influencing Se nutritional status. There was close association between Se deficiency and household wealth, with 70, 68, 59, 59, and 56 percent of WRA from households in the poorest to wealthiest quintiles, respectively, below the threshold for optimal GPx3 activity. These results are consistent with estimates of inadequate dietary Se supplies among 92, 86, 81, 72, and 51 percent of households from the poorest to wealthiest quintiles, respectively. The prevalence of Se deficiency among WRA in urban areas was lower than in rural areas (34% compared to 62% using the threshold for optimal GPx3 activity). Although the spatial statistical analysis in this study focuses on WRA, due to accepted deficiency thresholds, the potential risks of Se deficiency among children are also of great concern.
Conclusions
These findings provide robust evidence of widespread Se deficiency in Malawi across all demographic groups. We demonstrate that the prevalence of Se deficiency is under strong environmental controls with the entry of Se into food systems severely constrained by soil factors. There is limited scope to alleviate Se deficiency through increased dietary diversity with the concentration of Se in livestock products (as well as livestock productivity and health) constrained unless animals have access to Se supplements in feeds. Thus, deficiency is likely to remain high even with urbanization and increasing wealth. From a public health perspective, Se deficiency has similarities to iodine deficiency whereby some local food systems are unable to supply adequate amounts for human (or livestock) nutrition. Iodine deficiency has been effectively addressed in many countries including Malawi through iodization of table salt, although this is unlikely to be an appropriate approach for Se. Agronomic biofortification of maize using Se-enriched fertilizers has been proposed as a potential cost-effective strategy to alleviate Se deficiency in Malawi, as previously adopted in Finland. The efficacy and effectiveness of any fertilizer-based intervention would need to be assessed carefully in the context of other public health spending.
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