Growing concern has been expressed about uranium (U) accumulation in agricultural soils caused by the long-term application of mineral fertilizers. More than 80% of naturally occurring U transfers from phosphate rock (PR), the raw material used in mineral fertilizer production, to phosphorus (P) fertilizers. These fertilizers are then distributed on agricultural soils, where the U could accumulate over time and become a risk to the environment. The objective of this work was to review the reported content of U in P fertilizers, its potential dispersion in soils, and its uptake by plants in different countries in the world as reported in the literature. The articles for this systematic review were selected from the Scopus database published between 2003 and 2022. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) protocol were used. A total of 54 articles were assessed based on the standard inclusion and exclusion criteria. U concentrations in P fertilizers, agricultural soil dissemination, and plant uptake for available data were obtained and assessed. In order to compare a set of related data from the collected articles, box and whisker plots showing the distribution of U in P fertilizers are presented by region. The results from the reviewed articles show that the U concentrations in P fertilizer were in the range of 0.1–653 mg kg⁻¹. Interestingly, Minjingu P fertilizers from Tanzania, which are used in six East African countries, showed the highest U concentrations (159 to 653 mg kg⁻¹, average 390 mg kg⁻¹). The reported U concentrations for these fertilizers are, in fact, comparable to those of conventional low-grade uranium deposits mined in Namibia and elsewhere. Additionally, approximately 96% of the reviewed articles indicate that fertilized soil has higher U concentrations than non-fertilized soils, hinting at a measurable effect of mineral fertilizer use. The review recommends U extraction during mineral fertilizer production so that potential environmental risks can be reduced and U resources that would otherwise be lost can be recovered and used to substitute conventional U mining elsewhere.

The insecticidal efficacy of 10%, 5% and 1% w/v of Tephrosia vogelii, Croton dichogamus and Syzygium aromaticum aqueous plant extracts were assessed against larvae of Plutella xylostella and Trichoplusia ni on Brassica oleracea var. capitata crop field. Synthetic organophosphate pesticide (Chlorpyrifos) was used as a positive control and the negative controls were water and water plus soap. It was revealed that, aqueous plant extracts significantly (P ≤ 0.05) controlled the number of P. xylostella and T. ni larvae compared to negative controls. The 10% concentration of aqueous plant extracts showed significant higher efficacy in terms of reducing the insect population and their damage than 1% and 5 % concentration. The population of P. xylostella larvae per B. oleracea in five weeks of treatment applications at 10% w/v of T. vogelii, C. dichogamus and S. aromaticum aqueous plant extracts were 0.08, 0.15, 0.13, 0.05 and 0.08; 0.08, 0.20, 0.15, 0.13 and 0.18; 0.03, 0.05, 0.15, 0.18 and 0.13, respectively which was significantly (P ≤ 0.05) lower than in water (1.13, 1.68, 2.28, 2.20 and 3.28) and water plus soap (0.75, 1.60, 2.58, 1.83 and 3.30) negative controls respectively. The number of T. ni larvae per B. oleracea in five weeks of treatment applications at 10% w/v of T. vogelii, C. dichogamus and S. aromaticum of aqueous plant extracts were 0.00, 0.03, 0.05, 0.03 and 0.00; 0.03, 0.08, 0.05, 0.08 and 0.08; 0.05, 0.03, 0.00, 0.05 and 0.03, respectively which was significantly (P ≤ 0.05) lower than in water (0.50, 0.63, 0.60, 0.48 and 0.78) and water plus soap (0.30, 0.48, 68, 0.65 and 0.80) negative controls. The percentage damage of B. oleracea in five weeks of treatment applications at 10% w/v of T. vogelii, C. dichogamus and S. aromaticum aqueous plant extracts were 10.0, 6.3, 7.5, 7.5 and 5.6; 11.3, 11.3, 11.3, 11.3 and 12.5; 8.8, 8.1, 6.9, 8.1 and 9.4, respectively compared with water (33.8, 33.1, 38.8, 45.0 and 70.6) and water plus soap (30.0, 31.9, 41.3, 41.3 and 56.3). These pesticidal plants can be recommended for smallholder farmers to significantly control P. xylostella and T. ni larvae in B. oleracea crop.

The presence of radiotoxic uranium (U) in mineral fertilizers is of global concern. A pilot study was conducted in Tabora (Tanzania) to determine the release of U from three brands of phosphate fertilizers and its impact on soil bacteria. The experiment used three types of fertilizer: Minjingu Powder (MP), Nafaka Plus (NP), a mixed and granulated fertilizer made from Minjingu Phosphate Rock (MPR), and YaraMila Cereal (YC) fertilizer. There was also a control treatment that was not fertilized (NF). Alpha diversity and the R tool were used to analyze bacterial diversity in four samples within an average sequencing depth of 74,466 reads, using metrics like ASVs, Shannon index, and Chao1. The results showed that the number of amplicon sequence variants (ASVs) in the DNA from soil bacteria decreased, specifically to 400 ASVs, in the NP treatment, which was in line with the higher U concentration (3.93 mg kg⁻¹) in the soils. In contrast, the MP fertilizer treatment, associated with a lower U concentration (3.06 mg kg⁻¹) in soils, exhibited an increase in ASVs within the DNA of soil bacteria, reaching 795; the highest ASV value (822) was observed in the NF treatment. Higher amounts of U in the soil plots seemed to have resulted in more types of bacteria, with the Actinobacteriota phylum being the most common in all of the treatments. The NP (3.93 mg kg⁻³ U concentration) and MP (3.06 mg kg⁻³ U concentration) treatments were the only ones that showed Halobacteriota and Crenarchaeota phyla. Nonetheless, bacterial diversity may also account for the alterations in soil phosphorus and nitrogen following fertilizer application. The YaraMila Cereal treatment did not seem to be linked to any particular bacterial phylum. This means that in this study it did not have any measurable effect on the soil bacteria species compared to the MP and NP treatments.

The effectiveness of 1, 5, and 10% w/v of aqueous extracts of Croton dichogamus, Tephrosia vogelii, and Syzygium aromaticum and their mixture (2.5 and 5%) was evaluated against Myzus persicae on Brassica oleracea under field conditions. The synthetic chemical insecticide, chlorpyrifos, was used as positive control, and water and water plus soap were used as negative controls. Aqueous extracts significantly ( ) lowered M. persicae population compared with negative controls. The 5% of the aqueous extract from mixed plants and 10% of each plant used in this study significantly ( ) reduced aphid, M. persicae population comparable to chlorpyrifos in 2019 and 2020. However, the 1 and 5% concentrations of aqueous extracts of C. dichogamus, T. vogelii, and S. aromaticum and 2.5% of aqueous extracts from the mixed plants significantly lowered the population of M. persicae compared with negative controls in 2019 and 2020 wet seasons. The weekly observations revealed that, at weeks 1, 2, 3, 4, and 5 after application of treatments, the population of M. persicae differed significantly ( ). Also, the aqueous extracts from the mixed plants at 5% concentrations significantly ( ) reduced M. persicae population as compared with other treatments. It was as effective as synthetic chemical pesticide (chlorpyrifos). Also, 1 and 5% of C. dichogamus, T. vogelii, and S. aromaticum and the 2.5% of aqueous extracts from the mixed plants significantly reduced the population of M. persicae for all 6 weeks of study compared with negative controls. Therefore, these pesticidal plants can be recommended to smallholder farmers for the control of M. persicae in B. oleracea crops.

Clean water accessibility is vital to human health and well-being, a fundamental human right. Over 1.7 billion people do not have consistent access to safe drinking water, negatively affecting their health and socioeconomic status. Despite global recognition of clean water as a fundamental human right, many households in peri-urban areas of developing countries, including northern Tanzania, continue to face significant challenges in accessing reliable water sources. In the Kikwe peri-urban ward, disparities in access to clean water are influenced by various social determinants such as education level, gender roles, marital status, and proximity to water sources. These social factors contribute to unequal water distribution and increased vulnerability to waterborne diseases and economic burdens, especially among women and marginalized groups. However, limited empirical data exists on how these social determinants specifically affect household water access in Kikwe, hindering the development of targeted, evidence-based interventions. This study, therefore, aimed to investigate the social determinants of household clean water accessibility in Kikwe peri-urban ward of northern Tanzania. The cross-sectional survey combined quantitative and qualitative research methods on 353 respondents sampled from the Kikwe ward. Inference and descriptive statistics were employed to analyze the social determinants and respective associations with clean water accessibility. Results show that 64% of respondents finished elementary school, 53% were male, the majority 25.8% aged between 45 to 54, 73.7% were married, 37.4% rely on water from the rivers, 33.7% use public standpipes as the primary source of water, 62.9% female primarily responsible for fetching water and 84.7% of users do not treat water for their daily use. A weak significant correlation existed between water sources and social variables tested, implying clean water is an essential commodity, which needs to be distributed equally regardless of individual status. The findings highlight that clean water accessibility in peri-urban Kikwe is significantly influenced by social inequalities, particularly gender, and proximity to water sources. While the statistical correlations were weak, the trends point to systemic disparities that require deliberate policy attention. It is concluded that equitable access to clean water cannot be achieved without addressing these underlying social determinants. Therefore, it is recommended that targeted educational programs using mobile platforms be introduced to enhance awareness on water treatment and conservation. Additionally, empowering communities through participatory water governance, investing in affordable and decentralized water treatment solutions, and improving local infrastructure is critical for long-term water security and public health resilience in peri-urban areas like Kikwe.