SEGH Articles

# Award for work on tackling hidden hunger

25 March 2016
Estimates suggest that more than 2 billion people could be suffering from micronutrient deficiencies.

Estimates suggest that more than 2 billion people could be suffering from micronutrient deficiencies. Among those searching for solutions to this global problem is Muneta Grace Manzeke – a PhD student from the University of Zimbabwe whose work in Zimbabwe is being supported through a new Royal Society-Department for International Development (DFID) Africa Capacity Strengthening Initiative led by The University of Nottingham and the British Geological Survey.

Grace, a PhD student under the Soil Fertility Consortium for Southern Africa (SOFECSA) Research Group in the Department of Soil Science and Agricultural Engineering at the University of Zimbabwe, is looking at on-farm micronutrient malnutrition through understanding factors affecting bioavailability of selenium, zinc and iron in tropical soils. She is also investigating the influence of diverse farmer soil fertility management techniques on crop productivity and human nutrition.

Her work could prove so beneficial to on-farm crop nutrition she has been recognised by the International Fertiliser Society, becoming the first recipient of the Brian Chambers Award for early career researchers in crop nutrition. The award is an industry accolade for researchers working at the MSc or PhD level, who can demonstrate how their work will provide practical benefits to farm crop nutrition. It also provides a cash prize of £1,000 for the winner.

Micronutrient deficiencies lead to impaired physical and cognitive development, increased risk of morbidity in children and reduced work productivity in adults. Selenium and zinc have vital roles in keeping the immune system healthy and iron deficiency and anaemia result in poor pregnancy outcomes.

Grace said: “Smallholder rain-fed agriculture supports livelihoods of more than 60% of the Zimbabwean population. Like any system, it faces various challenges that include poor soils, poor crop yields and climate variability among others. Working in these communities for over 10 years now, SOFECSA partners at the University of Zimbabwe have been promoting impact-oriented research for development through a multi-institutional and inter-disciplinary approach. This has opened an avenue of research that could be explored in these farming communities, some of which require external regional and international support including relevant skills and knowledge to address the inherent and emerging challenges.”

The wider programme – Strengthening African capacity in soil geo-chemistry to inform agricultural and health policies – supported by The University of Nottingham and the British Geological Survey Centre for Environmental Geochemistry –involves core PhD projects based at partner institutions: Lilongwe University of Agriculture and Natural Resources, the Department of Agricultural Research in Malawi; the University of Zambia, the Zambian Agricultural Research Institute, and the Copperbelt  University in Zambia, and the Chemistry & Soils Research Institute in Zimbabwe.

For her Masters, also supported by SOFECSA, Grace specifically focused on exploring the effectiveness of different fertilizer formulations to alleviate zinc deficiency in smallholder maize production systems in Zimbabwe. Grace’s Professional Fellowship to the UK in 2015 was funded by the Commonwealth Scholarship Council UK. She has four publications on zinc nutrition and integrated soil fertility management including papers published in Plant and Soil and Field Crops Research.

Martin Broadley, Professor of Plant Nutrition, in the School of Biosciences at Nottingham, said: “The aim of the current programme is to strengthen the rresearch capacity of universities and research institutions in sub-Saharan Africa (SSA) through focusing on the training of students and technical staff in Africa. Our project is in the priority area of soil science, with a specific focus on how soils underpin healthy nutrition, especially for those involved in producing their own food.  The initial project runs until 2020, however, we are delighted to have attracted additional studentships into the network already, as we seek to ensure the long-term sustainability of this programme.”Other joint network PhD projects focus on wider agriculture and public health questions developed in collaboration with our African partners.”

Martin’s blog with BGS on the project can be found here and follow the project on twitter @AfricaGeochem

Keep up to date

## 34th SEGH International Conference: Geochemistry for Sustainable Development

Victoria Falls, Zambia

02 July 2018

## SubmitContent

Members can keep in touch with their colleagues through short news and events articles of interest to the SEGH community.

## Science in theNews

Latest on-line papers from the SEGH journal: Environmental Geochemistry and Health

• Fertilizer usage and cadmium in soils, crops and food 2018-06-23

### Abstract

Phosphate fertilizers were first implicated by Schroeder and Balassa (Science 140(3568):819–820, 1963) for increasing the Cd concentration in cultivated soils and crops. This suggestion has become a part of the accepted paradigm on soil toxicity. Consequently, stringent fertilizer control programs to monitor Cd have been launched. Attempts to link Cd toxicity and fertilizers to chronic diseases, sometimes with good evidence, but mostly on less certain data are frequent. A re-assessment of this “accepted” paradigm is timely, given the larger body of data available today. The data show that both the input and output of Cd per hectare from fertilizers are negligibly small compared to the total amount of Cd/hectare usually present in the soil itself. Calculations based on current agricultural practices are used to show that it will take centuries to double the ambient soil Cd level, even after neglecting leaching and other removal effects. The concern of long-term agriculture should be the depletion of available phosphate fertilizers, rather than the negligible contamination of the soil by trace metals from fertilizer inputs. This conclusion is confirmed by showing that the claimed correlations between fertilizer input and Cd accumulation in crops are not robust. Alternative scenarios that explain the data are presented. Thus, soil acidulation on fertilizer loading and the effect of Mg, Zn and F ions contained in fertilizers are considered using recent $$\hbox {Cd}^{2+}$$ , $$\hbox {Mg}^{2+}$$ and $$\hbox {F}^-$$ ion-association theories. The protective role of ions like Zn, Se, Fe is emphasized, and the question of Cd toxicity in the presence of other ions is considered. These help to clarify difficulties in the standard point of view. This analysis does not modify the accepted views on Cd contamination by airborne delivery, smoking, and industrial activity, or algal blooms caused by phosphates.

• Effects of conversion of mangroves into gei wai ponds on accumulation, speciation and risk of heavy metals in intertidal sediments 2018-06-23

### Abstract

Mangroves are often converted into gei wai ponds for aquaculture, but how such conversion affects the accumulation and behavior of heavy metals in sediments is not clear. The present study aims to quantify the concentration and speciation of heavy metals in sediments in different habitats, including gei wai pond, mangrove marsh dominated by Avicennia marina and bare mudflat, in a mangrove nature reserve in South China. The results showed that gei wai pond acidified the sediment and reduced its electronic conductivity and total organic carbon (TOC) when compared to A. marina marsh and mudflat. The concentrations of Cd, Cu, Zn and Pb at all sediment depths in gei wai pond were lower than the other habitats, indicating gei wai pond reduced the fertility and the ability to retain heavy metals in sediment. Gei wai pond sediment also had a lower heavy metal pollution problem according to multiple evaluation methods, including potential ecological risk coefficient, potential ecological risk index, geo-accumulation index, mean PEL quotients, pollution load index, mean ERM quotients and total toxic unit. Heavy metal speciation analysis showed that gei wai pond increased the transfer of the immobilized fraction of Cd and Cr to the mobilized one. According to the acid-volatile sulfide (AVS) and simultaneously extracted metals (SEM) analysis, the conversion of mangroves into gei wai pond reduced values of ([SEM] − [AVS])/f oc , and the role of TOC in alleviating heavy metal toxicity in sediment. This study demonstrated the conversion of mangrove marsh into gei wai pond not only reduced the ecological purification capacity on heavy metal contamination, but also enhanced the transfer of heavy metals from gei wai pond sediment to nearby habitats.

• Cytotoxicity induced by the mixture components of nickel and poly aromatic hydrocarbons 2018-06-22

### Abstract

Although particulate matter (PM) is composed of various chemicals, investigations regarding the toxicity that results from mixing the substances in PM are insufficient. In this study, the effects of low levels of three PAHs (benz[a]anthracene, benzo[a]pyrene, and dibenz[a,h]anthracene) on Ni toxicity were investigated to assess the combined effect of Ni–PAHs on the environment. We compared the difference in cell mortality and total glutathione (tGSH) reduction between single Ni and Ni–PAHs co-exposure using A549 (human alveolar carcinoma). In addition, we measured the change in Ni solubility in chloroform that was triggered by PAHs to confirm the existence of cation–π interactions between Ni and PAHs. In the single Ni exposure, the dose–response curve of cell mortality and tGSH reduction were very similar, indicating that cell death was mediated by the oxidative stress. However, 10 μM PAHs induced a depleted tGSH reduction compared to single Ni without a change in cell mortality. The solubility of Ni in chloroform was greatly enhanced by the addition of benz[a]anthracene, which demonstrates the cation–π interactions between Ni and PAHs. Ni–PAH complexes can change the toxicity mechanisms of Ni from oxidative stress to others due to the reduction of Ni2+ bioavailability and the accumulation of Ni–PAH complexes on cell membranes. The abundant PAHs contained in PM have strong potential to interact with metals, which can affect the toxicity of the metal. Therefore, the mixture toxicity and interactions between diverse metals and PAHs in PM should be investigated in the future.