Said Ali Vuai

Delineation of groundwater provenance in a coastal aquifer using statistical and isotopic methods, Southeast Tanzania

Rapid population growth and urbanization has placed a high demand on freshwater resources in southeast costal Tanzania. In this paper, we identify the various sources of groundwater and the major factors affecting the groundwater quality by means of multivariate statistical analyses, using chemical tracers and stable isotope signatures. The results from hierarchical cluster analyses show that the groundwater in the study area may be classified into four groups. A factor analysis indicates that groundwater composition is mainly affected by three processes, accounting for 80.6% of the total data variance: seawater intrusion, dilution of groundwater by recharge, and sewage infiltration. The hydrochemical facies of shallow groundwater was mostly of the Na–Ca–Cl type, although other water types were also observed. The deep groundwater samples were slightly to moderately mineralized and they were of the NaHCO3 type. This water type is induced mainly by dissolution of carbonate minerals and modified by ion exchange reactions. The signal from the stable isotope composition of the groundwater samples corresponded well with the major chemical characteristics. In the shallow groundwater, both high-nitrate and high-chloride concentrations were associated with localized stable isotope enrichments which offset the meteoric isotopic signature. This is inferred to be due to the contamination by influx of sewage, as well as intrusion by seawater. The depleted stable isotope values, which coincides with a chemical signature for the deep aquifer indicates that this deep groundwater is derived from infiltration in the recharge zone followed by slow lateral percolation. This study shows that a conceptual hydrogeochemical interpretation of the results from multivariate statistical analysis (using HCA and FA) on water chemistry, including isotopic data, provides a powerful tool for classifying the sources of groundwater and identifying the significant factors governing the groundwater quality. The derived knowledge generated by this study constitutes a conceptual framework for investigating groundwater characteristics. This is a prerequisite for developing a sound management plan, which is a requirement for ensuring a sustainable exploitation of the deep aquifer water resource in the coastal area of Tanzania.

Reliability analysis of roof rainwater harvesting systems in a semi-arid region of sub-Saharan Africa: case study of Mekelle, Ethiopia

ABSTRACT Curbing water scarcity problems in semi-arid regions is a top priority for economic and social development. Alternative strategies for sustainable domestic water supply are therefore required to augment water supply with affordable cost and technology. Scant research findings in sub-Saharan Africa have, however, reported inefficiency in adapting to water scarcity problems in the region. Therefore, an investigation of domestic rainwater harvesting (RWH) reliability is important to identify factors affecting the system. We found that rainwater harvesting with the existing traditional RWH systems in Mekelle city was unreliable. Unreliability was attributed to inefficient design (the systems were installed without considering deterministically the stochastic nature of rainfall), family size, water demand, rooftop area and storage tank size. Editor M.C. Acreman; Associate editor S. Kanae

Socio-economic and spatial correlates of subclinical iodine deficiency among pregnant women age 15–49 years in Tanzania

BackgroundIodine deficiency is a widespread global health problem that affects about 2 billion people each year. Pregnant women are particularly vulnerable to iodine deficiency due to increased iodine requirement leading to death, miscarriage, and stillbirth. Iodine deficiency also has significant negative effects on newborns including impaired cognitive development, impaired learning capabilities, and stunting. This study looks at the association between subclinical iodine deficiency and demographic factors including age, wealth index, education, family size, geographical zone, number of children, fish consumption, pregnancy trimester and household salt in pregnant women aged 15–49 years in Tanzania.MethodsThe 2010 Tanzania Demographic and Health Survey (TDHS) data was re analysed. Subclinical iodine deficiency is classified as a urinary iodine concentration (UIC) of <150 μg/L.ResultsResults showed that the prevalence of iodine deficiency (54%) was unacceptably high among pregnant women. The results of multiple logistic regression model found that number of children, wealth index, household salt, and geographical zone were significantly associated with iodine deficiency in these women.ConclusionThese results indicate a need to implement interventions to increase iodine intake that targets pregnant women with the specific demographic characteristics.

Maternal Dietary Diversity and Growth of Children Under 24 Months of Age in Rural Dodoma, Tanzania:

Objective: To identify predictors of maternal dietary diversity in rural Dodoma, Tanzania and assess its association with child growth outcomes. Methods: A cross-sectional survey of 361 mothers with children under 24 months of age was conducted in 5 villages in rural Dodoma, Tanzania. Maternal diets were assessed using food frequency questionnaires, and dietary diversity was categorized using Minimum Dietary Diversity for Women (MDD-W) guidelines. Child anthropometric measures were taken to calculate height-for-age z-score (HAZ), weight-for-height z-score (WHZ), and weight-for-age z-score (WAZ). Linear and logistic regressions were used to examine the association between maternal dietary diversity and children’s growth outcomes. Results: About 40% of mothers did not consume a diverse diet (MDD-W < 5), and 35% of children were stunted. Household production of greater number of crops was associated with greater MDD-W scores (P < .01). Greater maternal dietary diversity was associated with significantly greater child WHZ (mean difference = 0.44; 95% confidence interval [CI]: 0.10-0.78; P = .01), WAZ (mean difference = 0.37; 95% CI: 0.08-0.65; P = .01), and reduced risk of wasting (odds ratio = 0.22; 95% CI: 0.07-0.66; P = .01). Conclusions: Greater maternal dietary diversity was associated with improved child WHZ and WAZ outcomes. Sustainable interventions to increase maternal dietary diversity may improve WHZ and WAZ in young children in similar settings.

Determinants of undernutrition among women of reproductive age in Tanzania mainland

Abstract Objective: Developing countries, including Tanzania, are increasingly characterised by undernutrition. It is very disheartening, affecting a large proportion of the country’s population. Women in the reproductive age group are affected the most. Undernourished women are likely to face reproductive health problems, leading to maternal and infant death. Thus, studying and eliminating undernutrition risk factors in women is very important in order to avoid maternal health complications and prevent infant illness and death. Therefore, this study focused on identifying the determinant factors of undernutrition in women of reproductive age, i.e. aged 15-49 years, on the Tanzania mainland, using the data extracted from the Tanzanian Demographic and Health Survey 2010. Subjects and setting: Six thousand, nine hundred and thirty-three eligible non-pregnant women of reproductive age were selected from urban and rural areas on the Tanzania mainland. Design: A cross-sectional study was conducted. Outcome measures: An anthropometric measure (body mass index) was used to determine the prevalence of undernutrition and the generalised estimating equation (GEE) was adopted to assess the impact of the proposed determinants of undernutrition. Results: It was shown from the findings of this study that overall prevalence of undernutrition was 11%. Also, the results from the fitted GEE revealed that the effect of age, the family’s wealth index and marital status were independent significant risk factors for undernutrition. The impact of education on undernutrition was significantly associated with place of residence. Conclusion: There was a high prevalence of undernutrition in this study, with significant differences with respect to age, wealth index and marital status. In order to improve women’s nutritional status, policies should focus on improving family wealth and education.Objective: Developing countries, including Tanzania, are increasingly characterised by undernutrition. It is very disheartening, affecting a large proportion of the country’s population. Women in t...

Disparities in Risk Factors Associated with Obesity between Zanzibar and Tanzania Mainland among Women of Reproductive Age Based on the 2010 TDHS

The occurrence of overweight and obesity has serious health implications. The 2010 Tanzania Demographic and Health Survey data set was reanalysed to compare the prevalences of overweight and obesity between Mainland Tanzania and Zanzibar and to determine how demographic factors can predict overweight and obesity across the United Republic of Tanzania. About 7.92% of the Tanzanian women of reproductive age were obese, 15% were overweight, and 11.5% were underweight. Women from Mainland Tanzania (6.56%) were significantly less likely (AOR = 0.66, 95% CI: 0.53–0.82) to be affected by obesity as compared to women from Zanzibar (12.19%). The common predictors of obesity in Mainland Tanzania and Zanzibar were wealth index, marital status, and age. Whereas the place of residence and education level emerged as predictors of obesity in the Mainland Tanzania alone, the number of meals per day did so in Zanzibar. Most importantly, Zanzibar had a greater prevalence of obesity compared to Mainland Tanzania.