SEGH Articles

Ecosystem services to alleviate micronutrient malnutrition in Sub Saharan Africa

20 May 2011
Ecosystem Services concepts have great potential for linking biogeochemistry, health and policy formulation for poverty alleviation.

Mineral malnutrition due to environmental and cultural factors is widespread in sub-Saharan Africa (SSA).  A multi-national research consortia led by the University of Nottingham (UoN) undertook a pump priming project to explore if Ecosystem Services could provide an effective conceptual framework to link biogeochemical cycles of dietary minerals and poverty.  The project initially focussed on iodine, selenium and zinc in Malawi and Zambia.  Through data integration, feasibility studies, networking and capacity building we addressed three target themes: Biogeochemistry, Nutrition, and Economics.

Biogeochemistry: we developed a new GIS (ArcGIS) framework linking soil and land-use data has been submitted for open-access peer review publication.  New geochemical data for soils and vegetation were incorporated from an aligned project (UoN) and other spatial data (e.g. DFID FarmLime, BGS). Through integration of soil types in GIS, we have found that the population Se intake from maize is typically 6-7 µg Se per day, which represents ~10% of the dietary requirements for Se. Since maize provides the majority of dietary energy to the rural poor of SSA, this study revealed for the first time that chronic Se deficiency is endemic for the majority of the population and is largely influenced by input from soil.

Major knowledge gaps still exist.  Further  sampling, capacity building and data integration activities were therefore planned at a workshop in Lilongwe in September 2010 with multiple government departments and regional academics for future funding application.

  

 

 

 

 

 

 

 

Nutrition: a feasibility study was completed to study the spatial variation in I, Se and Zn dietary intake and status  in Malawi as a case study.  The National Health Sciences Research Committee of the Malawi Ministry of health granted ethical approval for dietary and biomarker surveys and intake analyses across several villages.  Importantly, sensitisation visits to the villages and farmers was undertaken by extension services, Ministry of Health and PI's.  Data showing strong geochemical control of intake and status, and these will be submitted for publication later in 2011. 

Economics: a novel Ecosystem Services framework was developed based on: modelling soil-to-diet relationship using mineral / dietary-energy units; food choices and land-use; quantifying relationship between disease burdens and poverty at population levels. Economic analyses were formalised using World Health Organisation Disability Adjusted Life Years (DALYS), which incorporated a willingness to pay for intervention.   Such analyses provide a useful policy tool at national and regional scales. 

For example: despite limited data, a pilot analysis estimated that 3,955 healthy life years (DALYS) per 1m population per year are lost each year in Malawi due to Zn deficiency alone, mostly due to infant mortality.  This represents an economic loss to Malawi of >1% GDP per year.  Economic analyses for I, Se and other elements requires more data. 

This work was funded via the Ecosystem Service Poverty Alleviation programme by UK DFID-NERC.

Project partners included: British Geological Survey, University of East Anglia, Genius Consultancy, University of Sabanci, University of Adelaide, University of Otago, University of Malawi, University of Zambia, Ministry of Agriculture & Health (Malawi).

Dr Martin Broadley, University of Nottingham.  martin.broadley@nottingham.ac.uk

 

 

 

 

Keep up to date

Submit Content

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

Science in the News

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

  • Date palm waste biochars alter a soil respiration, microbial biomass carbon, and heavy metal mobility in contaminated mined soil 2017-04-19

    Abstract

    A 30-day incubation experiment was conducted using a heavy metal-contaminated mined soil amended with date palm feedstock (FS) and its derivative biochars (BCs) at three pyrolysis temperatures of 300 (BC-300), 500 (BC-500), and 700 °C (BC-700) with different application rates (0.0, 5, 15, and 30 g kg−1) to investigate their short-term effects on soil respiration (CO2–C efflux), microbial biomass carbon (MBC), soil organic carbon (SOC), mobile fraction of heavy metals (Cd, Cu, Pb, Zn, Mn, and Fe), pH, and electrical conductivity (EC). The results showed that FS and BC-300 with increasing addition rate significantly reduced soil pH, whereas SOC, CO2–C efflux, and soil MBC were increased compared to the control. On the contrary, BC-500 and BC-700 increased soil pH at early stage of incubation and have small or no effects on SOC, CO2–C efflux, and MBC. Based on the results, the date palm biochars exhibited much lower cumulative CO2–C efflux than feedstock, even with low-temperature biochar, indicating that BCs have C sequestration potential. Applying BC-700 at 15 and 30 g kg−1 significantly reduced cumulative CO2–C efflux by 21.8 and 45.4% compared to the control, respectively. The incorporation of FS into contaminated soil significantly increased the mobile content of Cd and Mn, but decreased the mobile content of Cu. However, BC-300 significantly reduced the mobile content of Cd, Cu, Pb, and Zn. It could be concluded that low-temperature biochar could be used as a soil amendment for reducing heavy metal mobility in mining contaminated soil in addition to minimize soil CO2–C efflux.

  • Historical record of anthropogenic polycyclic aromatic hydrocarbons in a lake sediment from the southern Tibetan Plateau 2017-04-17

    Abstract

    High-altitude lake sediments can be used as natural archives to reconstruct the history of pollutants. In this work, the temporal distribution of polycyclic aromatic hydrocarbons (PAHs) was determined in a sediment core collected from the southern Tibetan Plateau (TP), which was dated by using the 210Pb dating method and validated with the 137Cs fallout peak. The concentrations of the anthropogenic PAHs (Σ8PAH) in the sediment core ranged from 0.83 to 12 ng/g dw, and the fluxes of the Σ8PAH were in the range of 2.1–27 g/cm2/year. The temporal variations in the concentration and input flux of anthropogenic PAHs were low with little variability before the 1950s, and then gradually increased from the 1950s to the 1980s, and an accelerated increase was observed after the early 1980s. The content of total organic carbon played an insignificant role in affecting the time trends of PAHs in the sediment core. Diagnostic concentration fractions of PAH components indicate PAHs in the lake sediment of the southern TP which are mainly from biomass burning and/or from long-range atmospheric transport.

  • Determination of the potential implementation impact of 2016 ministry of environmental protection generic assessment criteria for potentially contaminated sites in China 2017-04-12

    Abstract

    The Ministry of Environmental Protection of China issued a 3rd draft edition of risk-based Generic Assessment Criteria (the MEP-GAC) in March 2016. Since these will be the first authoritative GAC in China, their implementation is likely to have a significant impact on China’s growing contaminated land management sector. This study aims to determine the potential implementation impact of the MEP-GAC through an in-depth analysis of the management context, land use scenarios, health criteria values adopted and exposure pathways considered. The MEP-GAC have been proposed for two broad categories of land use scenarios for contaminated land risk assessment, and these two categories of land use scenarios need to be further delved, and a MEP-GAC for Chinese cultivated land scenario ought to be developed, to ensure human health protection of Chinese farmers. The MEP-GAC have adopted 10−6 as the acceptable lifetime cancer risk, given the widespread extent and severe level of land contamination in China, consideration should be given to the decision on excess lifetime cancer risk of 10−5. During risk assessment process in practice, it is better to review the 20% TDI against local circumstances to determine their suitability before adopting it. The MEP-GAC are based on a SOM value of 1%, for regions with particularly high SOM, it might be necessary to develop regional GAC, due to SOM’s significant impact on the GAC developed. An authoritative risk assessment model developed based on HJ25.3-2014 would help facilitate the DQRA process in practice. The MEP-GAC could better reflect the likely exposures of China’s citizens due to vapour inhalation by using characteristics of Chinese exposure scenarios, including China-generic building stock, as inputs into the Johnson and Ettinger model as opposed to adoption of the US EPA parameters. The MEP-GAC once implemented will set the trajectory for the development of the investigation, assessment and remediation of land contamination for years.