Anemia in children aged 6-59 months was significantly associated with maternal anemia status in rural Zimbabwe.

Globally, anemia is a public health problem affecting mostly women of reproductive age (WRA, n = 452) and children aged 6-59 months (n = 452) from low- and lower-middle-income countries. This cross-sectional study assessed the prevalence and determinants of anemia in WRA and children aged 6-59 months in rural Zimbabwe. The venous blood sample was measured for hemoglobin utilizing a HemoCue machine. Anthropometric indices were assessed and classified based on World Health Organization standards. Socioeconomic characteristics were assessed. The median (±inter quartile range (IQR)) age of WRA was 29 ± 12 years and that for children was 29 ± 14 months. The prevalence of anemia was 29.6% and 17.9% in children and WRA, respectively, while the median (±IQR) hemoglobin levels were 13.4 ± 1.8 and 11.7 ± 1.5 g/dl among women and children, respectively. Multiple logistic regression analysis was used to assess determinants of anemia. Anemia in children was significantly associated with maternal anemia (odds ratio (OR) = 2.02; 95% CI 1.21-3.37; p = .007) and being a boy (OR = 0.63; 95% CI 0.41-0.95; p = .029), while anemia in WRA was significantly associated with the use of unimproved dug wells as a source of drinking water (OR = 0.36; 95% CI 0.20-0.66; p = .001) and lack of agricultural land ownership (OR = 0.51; 95% CI 0.31-0.85; p = .009). Anemia is a public health problem in the study setting. The positive association between maternal and child anemia reflects the possibility of cross-generational anemia. Therefore, interventions that focus on improving preconceptual and maternal nutritional status may help to reduce anemia in low-income settings.

Mineral micronutrient status and spatial distribution among the Ethiopian population.

Multiple micronutrient deficiencies are widespread in Ethiopia. However, the distribution of Se and Zn deficiency risks has previously shown evidence of spatially dependent variability, warranting the need to explore this aspect for wider micronutrients. Here, blood serum concentrations for Ca, Mg, Co, Cu and Mo were measured (n 3102) on samples from the Ethiopian National Micronutrient Survey. Geostatistical modelling was used to test spatial variation of these micronutrients for women of reproductive age, who represent the largest demographic group surveyed (n 1290). Median serum concentrations were 8·6 mg dl-1 for Ca, 1·9 mg dl-1 for Mg, 0·4 µg l-1 for Co, 98·8 µg dl-1 for Cu and 0·2 µg dl-1 for Mo. The prevalence of Ca, Mg and Co deficiency was 41·6 %, 29·2 % and 15·9 %, respectively; Cu and Mo deficiency prevalence was 7·6 % and 0·3 %, respectively. A higher prevalence of Ca, Cu and Mo deficiency was observed in north western, Co deficiency in central and Mg deficiency in north eastern parts of Ethiopia. Serum Ca, Mg and Mo concentrations show spatial dependencies up to 140-500 km; however, there was no evidence of spatial correlations for serum Co and Cu concentrations. These new data indicate the scale of multiple mineral micronutrient deficiency in Ethiopia and the geographical differences in the prevalence of deficiencies suggesting the need to consider targeted responses during the planning of nutrition intervention programmes.

Linkages between soil, crop, livestock, and human selenium status in Sub-Saharan Africa: a scoping review.

Selenium (Se) is essential for human health, however, data on population Se status and agriculture-nutrition-health linkages are limited in sub-Saharan Africa (SSA). The scoping review aims to identify linkages between Se in soils/crops, dietary Se intakes, and livestock and human Se status in SSA. Online databases, organisational websites and grey literature were used to identify articles. Articles were screened at title, abstract and full text levels using eligibility criteria. The search yielded 166 articles from which 112 were excluded during abstract screening and 54 full text articles were assessed for eligibility. The scoping review included 34 primary studies published between 1984 and 2021. The studies covered Se concentrations in soils (n = 7), crops (n = 9), animal tissues (n = 2), livestock (n = 3), and human Se status (n = 15). The evidence showed that soil/crop Se concentrations affected Se concentration in dietary sources, dietary Se intake and biomarkers of Se status. Soil types are a primary driver of human Se status and crop Se concentration correlates positively with biomarkers of Se dietary status. Although data sets of Se concentrations exist across the food system in SSA, there is limited evidence on linkages across the agriculture-nutrition nexus. Extensive research on Se linkages across the food chain is warranted.

Review: mine tailings in an African tropical environment-mechanisms for the bioavailability of heavy metals in soils.

Heavy metals are of environmental significance due to their effect on human health and the ecosystem. One of the major exposure pathways of Heavy metals for humans is through food crops. It is postulated in the literature that when crops are grown in soils which have excessive concentrations of heavy metals, they may absorb elevated levels of these elements thereby endangering consumers. However, due to land scarcity, especially in urban areas of Africa, potentially contaminated land around industrial dumps such as tailings is cultivated with food crops. The lack of regulation for land-usage on or near to mine tailings has not helped this situation. Moreover, most countries in tropical Africa have not defined guideline values for heavy metals in soils for various land uses, and even where such limits exist, they are based on total soil concentrations. However, the risk of uptake of heavy metals by crops or any soil organisms is determined by the bioavailable portion and not the total soil concentration. Therefore, defining bioavailable levels of heavy metals becomes very important in HM risk assessment, but methods used must be specific for particular soil types depending on the dominant sorption phases. Geochemical speciation modelling has proved to be a valuable tool in risk assessment of heavy metal-contaminated soils. Among the notable ones is WHAM (Windermere Humic Aqueous Model). But just like most other geochemical models, it was developed and adapted on temperate soils, and because major controlling variables in soils such as SOM, temperature, redox potential and mineralogy differ between temperate and tropical soils, its predictions on tropical soils may be poor. Validation and adaptation of such models for tropical soils are thus imperative before such they can be used. The latest versions (VI and VII) of WHAM are among the few that consider binding to all major binding phases. WHAM VI and VII are assemblages of three sub-models which describe binding to organic matter, (hydr)oxides of Fe, Al and Mn and clays. They predict free ion concentration, total dissolved ion concentration and organic and inorganic metal ion complexes, in soils, which are all important components for bioavailability and leaching to groundwater ways. Both WHAM VI and VII have been applied in a good number of soils studies with reported promising results. However, all these studies have been on temperate soils and have not been tried on any typical tropical soils. Nonetheless, since WHAM VII considers binding to all major binding phases, including those which are dominant in tropical soils, it would be a valuable tool in risk assessment of heavy metals in tropical soils. A discussion of the contamination of soils with heavy metals, their subsequent bioavailability to crops that are grown in these soils and the methods used to determine various bioavailable phases of heavy metals are presented in this review, with an emphasis on prospective modelling techniques for tropical soils.