Bridging the gap between water, sanitation and food production for improved food and nutrition security

Conveners: Helfrid Schulte-Herbrüggen, KTH Institute of Technology; Ngolia Kimanzu, Salvation Army International Development, and Björn Schulte-Herbrüggen, Stockholm Resilience Centre

Contact: hschulte@kth.se

There is a close link between the human right to safe drinking water and sanitation and the human right to food. Safe drinking water and sanitation are crucial for human health and nutritional up- take, while water and nutrients (often in the form of fertilizers) are indispensable for producing food.

The ambitions of the Sustainable Development Goals are that all people should have access to safe water and sanitation, and all people should have access to food. However, despite multiple linkages between water, sanitation and food production, these are often handled as separate sectors, both within research, governmental institutions and by practitioners. A holistic approach to providing clean drinking water, sanitation and ensuring nutritious food production is challenging and rarely addressed simultaneously. For instance, three separate safety planning frameworks have been developed by the WHO for water, sanitation and food, respectively.

The aim of the session is therefore to explore linkages and identify best practices and policy options for integrated management and cooperation, resulting in improved health and sustainable development of communities in developing countries.

The panel will 1) discuss findings from the SIANI Expert Group “Linkages between Water, Sanitation and Food production for Food and Nutrition Security”, including general links between sectors as well as knowledge and technology transfer between Sweden and developing countries; 2) discuss implications for development intervention policy and practices; 3) discuss lessons learnt from examples where water, sanitation and food production have been linked and 4) develop recommendations to improve policies on water, sanitation and food production for food and nutrition security, aimed at different actors at multiple levels, with a long-term perspective.

24 Aug., 09:00–10:30, William-Olsson Lecture Hall

  • Health risks associated with emerging drinking water pollutants in the Andean highlands. Florencia Harari, Karolinska Institutet; Esperanza Casimiro, Hospital Dr. Nicolás Cayetano Pagano and Marie Vahter, Karolinska Institutet.
  • Sustaining the sustainable – potentials and challenges of productive sanitation systems. Kim Andersson, Stockholm Environment Institute.
  • Closing the loop in Bamako, Mali. Sanata Traoré, Université de Bamako and Gunnar Jacks, KTH Royal Institute of Technology.
  • Benefits of early-life selenium status for cognitive function in childhood – evidence fromrural Bangladesh. Helena Skröder Löveborn, Maria Kippler and Marie Vahter, Karolinska Institutet.
  • Human fertilizer and the productivity of farming households. Jan Pettersson and Johan Wikström, Uppsala University.

Abstracts

Health risks associated with emerging drinking water pollutants in the Andean highlands. Florencia Harari, Karolinska Institutet; Esperanza Casimiro, Hospital Dr. Nicolás Cayetano Pagano and Marie Vahter, Karolinska Institutet.

Drinking water contamination by naturally occurring ground minerals may include arsenic, fluoride, manganese, uranium, boron and lithium. Well water is a common source of arsenic exposure and severe health effects worldwide, especially in low income areas. A few recent reports show elevated concentrations of lithium, up to several mg/L, in different countries. It is known that lithium at therapeutic doses (for bipolar disease) may impair fetal growth as well as calcium homeostasis and thyroid and kidney function. We recruited a mother-child cohort (n=180; mainly indigenous) in the northern part of the Argentinean Andes with wide variation of lithium in the drinking water (5-1,660μg/L). Measurement of thyroid function across pregnancy showed that blood lithium concentrations were positively associated with TSH and inversely associated with fT3 and T3 (adjusted for relevant covariates). Evaluation of calcium homeostasis showed that blood lithium concentrations were associated with an odds ratio of 4.6 for having vitamin D deficiency during pregnancy. We also found that lithium easily crosses the placenta and that newborns to mothers in the highest tertile of exposure were about 0.8cm shorter than those in the lowest tertile. Taken together, our results provide evidence that drinking water lithium may act as endocrine disruptor and impair fetal size. Evaluation of infant thyroid function in relation to early-life lithium exposure is ongoing. The findings raise the need for further studies of potential adverse health effects of drinking water pollution, in order to strengthen drinking water control and public health world-wide.

Sustaining the sustainable – potentials and challenges of productive sanitation systems. Kim Andersson, Stockholm Environment Institute.

Unsafe management of excreta and wastewater is widespread and creates significant health and environmental risks. There is an urgent need to change how we manage wastewater, excreta and other biomass waste in order to meet current and future resource needs while promoting sustainable development. This presentation will explore one of the most important potential ‘resource loops’ which links sanitation to food production. Closing this loop requires recovering plant nutrients from sanitation waste, which are essential inputs for agricultural production, and putting them back into agricultural use. Linked to this is the reuse of organic waste, which soils require to retain moisture, nutrients and soil microbes, and maintain its structural properties. Nutrients, organic matter and water from sanitation and wastewater streams can be returned to the soil by applying appropriate sanitary barriers, however, a critical challenge to ‘closing the loop’ requires identifying what resources are available in a particular context, what acceptance and demand there is for them and how they can be economically recovered while aligning with the existing institutional and regulatory frameworks. This presentation will highlight opportunities to improve agricultural productivity and soil quality through reuse of water, nutrients and organic matter from sanitation systems, as well as challenges in implementing and sustaining these “sustainable solutions”. In addition, the presentation will highlight how sustainable sanitation and wastewater management will be central to fulfilling the 2030 sustainable development agenda, including Goal 2 on improving food security.

Closing the loop in Bamako, Mali. Sanata Traoré, Université de Bamako and Gunnar Jacks, KTH Royal Institute of Technology.

Periurban agriculture becomes more important and provides a substantial part of the food items to towns in developing countries. Bamako is no exception in this regard. The recycling of organic matter and nutrients have come fairly far ahead in Bamako. A major actor is Eau et Assanissement en Afrique (EAA), formerly called CREPA. This report is product of a project concerning zinc deficiency in soils and food in periurban agriculture in Bamako. Zinc deficiency is a major problem in many tropical countries including Mali (Gårdestedt et al. 2009; Jacks et al. 2007). Urine separating latrines are common in suburban Bamako. A major problem with this type of sanitation is the need for storage of the urine in terms of vessels or built tanks which tend to be costly. This has been solved by composting urine together with organic waste. This solves the need for storage and provides hygienization of the urine in addition to providing a good soil amendment (Pettersson and Wikström 2012). Phosphorus and organic matter are urgently needed in Sahelian agriculture (Soumaré et al. 2003). In the zinc deficiency investigation it is found that zinc concentrations are higher and more available than in Sahelian soils in general. On reason may be a considerable amount of zinc recycled from the society. Other, potentially tpxic heavy metals are within safe limits. The source of zinc may be galvanized roofs, used dry batteries etc. The soil amendments analysed in the project are high in organic matter and nutrients. Thus the periurban agriculture seems to gain from the developed recycling in Bamako.   

Benefits of early-life selenium status for cognitive function in childhood – evidence from rural Bangladesh. Helena Skröder Löveborn, Maria Kippler and Marie Vahter, Karolinska Institutet.

Dietary intake of selenium, an essential micronutrient present in e.g. fish, offal’s, eggs, meat, varies markedly. Selenium is needed for antioxidative defense and thyroid hormone activation, important for early-life development. In our large mother-child cohort, nested in a randomized food and micronutrient supplementation trial in pregnancy in rural Bangladesh, where 60% of the women were selenium deficient (plasma levels <60 µg/L), a better selenium status in pregnancy (measured as blood selenium at gestational week 14) seemed beneficial for children’s cognitive function at 1.5 years. To assess whether the effect persists for later childhood development, we evaluated the association with child IQ at 5 and 10 years of age.  Cognitive function at 5 and 10 years was assessed using the Wechsler Pre-school and Primary Scale of Intelligence (3rd edition) and the Wechsler Intelligence Scale for Children (4th edition), respectively. In multivariable-adjusted regression analyses, children of women with higher blood selenium scored better on the different cognitive tests at both 5 and 10 years, particularly the girls. Further adjusting for maternal BMI, zinc, manganese, iodine, and hemoglobin did not affect the associations, and selenium appeared to be the most influential nutrient. We could not detect any difference in selenium concentrations between the supplementation groups (one including a multiple micronutrient tablets containing 60 µg selenium), indicating that it is indeed more efficient to improve the selenium status through a varied diet. This is also more sustainable, most often less expensive, and has a lower risk of excessive intake with associated toxicity.

Human fertilizer and the productivity of farming households. Jan Pettersson and Johan Wikström, Uppsala University.

Ecological sanitation offers both sanitation and fertilizer through recycling of nutrients. Human fertilizer provides a close to free addition of nutrients in household farming and may, therefore, decrease the downward risk of fertilizer adoption. We study an ecological sanitation investment program in southern Mali, where just over 150 beneficiaries got a urine diverting dry toilet installed. Our results suggest that the average household in our study is able to produce amounts of N, P, and K equivalent to around a fourth of its yearly expenditures on artificial fertilizers, corresponding to a yearly addition of nutrients or a yearly reduction in fertilizer expenditures to a value of about 50 €. However, the quantity and quality of N, P, and K actually retained is found to be only a fraction of this potential amount. Using propensity score matching methods, we find an increase in maize yields among beneficiary households, but no effect on the yields of other crops. Moreover, households substitute artificial fertilizer with human fertilizer at 10–15% of the average household use of artificial fertilizers. Thus, the substitution may worsen an already bad soil nutrient balance. Higher retention levels are needed for solutions to prove financially viable.