Joshua Olowoyo

Heavy metal contamination in drinking water remains a pervasive global challenge with significant consequences for environmental quality and human health. This review synthesizes findings from recent studies examining heavy metal concentrations in different sources of drinking water, including municipal tap water, groundwater, surface water, and bottled/sachet water across various geographical regions. The study used a systematic review of studies published from 2015 to 2024. The result showed a variation in the concentrations of heavy metals from all the sources, with tap water generally exhibiting lower heavy metal levels. Pb, Fe, Mn, and other metals persist in different sources and from many regions with levels above the permissible limits recommended by the World Health Organization (WHO) in some instances, which were sometimes linked to aging distribution systems and other pollution sources. Bottled and sachet water, commonly regarded as safer alternatives, also showed some levels of heavy metals such as Pb, Cd, and Cr, reflecting inconsistent packaging or production oversight. Surface waters display variability with heavy metals pollution, driven by industrial discharge, mining activities, agricultural runoff, and urban wastewater inputs. Groundwater sources, although naturally shielded, frequently contained elevated concentrations of As, Hg, and Ni due to both geological and anthropogenic factors. Pb concentrations were below detection limit in some of the published papers; however, the values reported in this study ranged from ND to 260.0 µg/L (tap water), ND to 0.259 mg/L (surface water), ND to 0.791 mg/L (groundwater), and ND to 123.15 µg/L (bottled water). Arsenic (As) concentrations ranged from ND to 692 µg/L from different sources, with the highest concentration from groundwater. Collectively, these patterns underscore the need for strengthened monitoring frameworks, improved water treatment technologies, and integrated pollution-prevention strategies. Addressing heavy metal contamination in drinking water requires coordinated policy approach and continuous monitoring to reduce human exposure and safeguard global public health.

Pollution of urban soils with metals is of great concern worldwide owing to their persistent and nonbiodegradable nature. The current study investigated the presence and levels of some selected potentially toxic elements in the roadside soil dust samples collected from Fort Myers and surrounding communities. The study further assessed the pollution and geoaccumulation indexes for some of the potentially toxic elements and the potential health risk associated with it. Soil samples were collected from 24 locations in the area, taking into consideration proximity to highways, industrial areas, residential areas, and shopping malls. Samples were analyzed for potentially toxic metal contents using a microwave plasma atomic emission spectrometer (MP‐AES). The result showed that Zn and Cu were higher in some of the selected sites than the allowable limit. Zn values ranged from 134.26 ± 14.70 mg/kg to 530.20 ± 201.70 mg/kg. The presence of Pb was also noted in all the samples, and the values ranged from 0.85 mg/kg to 33.03 mg/kg. Mn ranged from 26.79 ± 2.81 mg/kg to 347.42 ± 30.48 mg/kg, while Cu ranged from 2.44 ± 0.23 mg/kg to 172.30 ± 12.95 mg/kg. The highest concentration of Pb was reported from sites associated with vehicular emission. The pollution assessment index showed moderately polluted to polluted soil with Zn and Cu, and the geoaccumulation index results showed risk levels, from no pollution for Pb but extremely contaminated soils for Zn and Cu using the percentile suggested in a previous study. The highest EDI for both children and adults for Pb was recorded from children roadside Add ing with the value of 3.63 × 10 −5 ; for Cu, it was recorded from roadside Add ing with the value of 1.89 × 10 −4 ; and for Zn, it was recorded from car parking Add inh with the highest value of 5.81 × 10 −4 . The hazard quotient (HQ) for children and adults was all below 1, suggesting no potential health risk at this stage. Differences in the values recorded for all the trace metals analyzed were not statistically significant across the sites except for Zn in the current study ( p > 0.05). Since the study showed moderately polluted soil for Zn and Cu, it is therefore recommended that a continuous monitoring program should be in place to provide information on the levels of these trace metals from the study area. The current study provides baseline data on metal contamination in urban soils of Fort Myers, highlighting potential environmental and public health risks and the need for continuous monitoring to prevent long‐term exposure effects.

Southwest Florida is one of the fastest growing regions in the United States, heavily affected by anthropogenic activities, which may alter the composition of natural seawater. Polluted seawater may thus become a potential risk to coastal human populations and the ecosystem at large. The current study investigated seasonal variations in surface seawater along the Gulf coast of southwest Florida to determine potential anthropogenic inputs and the ecological impacts of heavy metals. Water samples were collected from 14 sampling locations at three different time points (October 2022, January 2023, and March 2023) following Hurricane Ian in September 2022. Samples were analysed for heavy metals (V, Cr, Mn, Ni, Zn, As, Rb, Mo, Cd, Sb, Pb, and U) using an Inductively Couple Plasma Mass Spectrometry (ICP-MS). The metal highest concentrations were found to be as follows, Zn (5096.81 ± 1.09 µg/L), Pb (387.84 ± 1.73 µg/L), Rb (237.46 ± 1.51 µg/L), Ni (131.29 ± 1.09 µg/L), Cr (32. 58 ± 1.29 µg/L), Mn (16.62 ± 1.22 µg/L), Mo (12.96 ± 0.43 µg/L), Cd (3.11 ± 8.87 µg/L), V (8.68 ± 0.76 µg/L), Sb (7.63 ± 0.31 µg/L), As (7.32 ± 0.47 µg/L), U (7.13 ± 0.00 µg/L). The Ecological risk index ranged from 1.01 to 83.75 in October 2022, 2.41–321.77 in January 2023, and 1.05–248.61 in March 2023, indicating high ecological risk due to the presence of heavy metals. Dermal hazard and ingestion indexes assessments were lower than one, indicating that no health risks to humans may result from dermal exposure at this stage. The presence of high concentrations of some heavy metals may be attributed to the impact of pollutants and possibly discharges from Hurricane Ian, thus the need for continuous monitoring. The present study may serve as baseline data for further research efforts to identify the source of these heavy metals in seawater as they may have detrimental effects on marine economically important organisms.

The current study assessed the curriculum and subjects used in high schools in different countries in teaching environmental issues. The study reviewed current policy, curriculum, delivery and challenges associated with the implementation of the policies associated with teaching Environmental Education in high schools. A systematic review approach of peer-reviewed journals between 2003 and 2023 involving Environmental Education only in High Schools was used. The review showed that EE is included in the curricula of most of the high schools from different countries but with low visibility and implementation strategies. Currently, EE does not stand alone as a subject but is housed in different subjects and mostly taught in science subjects (Geography and Biology) in high schools. Students in arts and social sciences classes have little exposure to EE. The review further showed that teachers' attitudes and knowledge of environmental issues remain a major setback in the teachings of the subject. Lack of infrastructure, time and teachers' availability are other factors affecting EE at high school. Clear direction is needed for the implementation of the EE in High Schools. A subject that teaches EE as a subject may be considered so that it is not viewed as a supporting subject by the students.

The dichotomy of striking a balance between sustainable food crop production for the skyrocketing human population and ensuring agricultural practices that mitigate environmental degradation has prompted much research into sustainable crop production methods. The application of amendments has become an integral part of arable soil management in restoring declining soil fertility for sustainable and high-quality crop production. This study was conducted on lettuce and carrot cultivated on soil treated with three different amendments: cow dung, sewage sludge, and nitrogen–phosphorus–potassium (NPK) mineral fertilizer. The vegetables were harvested at maturity at 60 and 110 days for lettuce and carrot, respectively, dried in a hot air oven, crushed, and then digested to obtain an aliquot sample. The level of macronutrients was quantified from the aliquots using inductively coupled plasma optical emission spectrometry (ICP-OES), Avio 550 Max, PerkinElmer, USA. It was observed that both soil treatment and types of vegetables significantly impacted the level of mineral contents in the vegetables. The highest values of 58.00 ± 8.36 mg/kg and 72.97 ± 12.53 mg/kg were recorded for Na and P in carrots from soil treated with sewage sludge, respectively. The highest values of 247.97 ± 17.07 mg/kg and 104.72 ± 4.12 mg/kg were recorded for Ca and Mg in lettuce from sewage sludge-treated soil, respectively. Similarly, the highest value of 546.75 ± 76.44 mg/kg for K was also recorded in lettuce, but from cow dung-treated soil. The overall pattern of mineral accumulation by vegetables shows that carrots accumulate more Na than lettuce, and lettuce accumulates more Mg, Ca, and K than carrots, while there was no significant difference in the level of P in both lettuce and carrots. The findings reveal that lettuce and carrots from soil treated with organic manure cow dung and sewage sludge accumulated higher mineral contents of most of the investigated minerals. It was also observed that lettuce accumulated higher contents of most of the minerals investigated. This study therefore concludes that organic manures are better alternatives to mineral fertilizers for vegetable production, which supports the effort to strike a balance between sustainable and ecofriendly agriculture.

The supply of water for domestic purposes from wells is common in some areas in the United States of America. However, research has shown that this underground water may become polluted with trace metals due to both natural and anthropogenic effects. The current study evaluated the levels of Trace Metals in well water from a community in Florida. The study further investigated the potential health risks associated with the levels of trace metals in the water samples. A total of 34 water samples (treated and untreated) were used for the study. The result showed the presence of Pb in both treated and untreated water samples (18.2 ± 1.8 µg/L – 117.7 ± 4.5 µg/L). Fe concentrations ranged from 10. 7± 2.2 µg/L – 940.1 ± 3.5 µg/L. Values obtained for Pb were higher than the recommended limit. Three of the water samples have Fe values above the recommended limit for human consumption. Differences obtained from the treated and untreated water samples for some of the trace metals were not significant (p<0.05). The health risk calculated in this study for Pb, and other trace metals did not show any potential health risk at this stage because the values were all <1. The ecological risk assessment also showed no threat to the environment at this stage with a caution for Pb and Cu due to the values obtained. The presence of Pb in water suggests the need for continuous monitoring of the water samples from the area and further investigation to the actual source of Pb may be necessary so as to ensure safety.

The conversion of industrial waste lignin into sustainable carbon materials is an essential step towards reducing dependency on fossil fuels and mitigating environmental impacts. This review explores various aspects of lignin utilization, with particular focus on the extraction of lignin and the application of lignin-derived carbon materials in energy storge applications. The review explores advanced chemical methods to improve the efficiency of biomass conversion, detailing emerging technologies for lignin extraction from various biomasses using innovative solvents and techniques, such as Ionic Liquids and Deep Eutectic Solvents (DESs). Additionally, it discusses the parameters that impact the hydrothermal carbonization (HTC) process. The produced hydrochar shows potential for use as optimized precursors for energy storage applications. This review also considers the implications of these technologies for environmental sustainability and the circular economy, suggesting future research directions to enhance and scale these processes for global impact. This comprehensive analysis highlights the critical role of advanced biomass conversion technologies in achieving sustainability and outlines pathways for future lignin-based carbon materials innovations.

This review investigates the levels of antibiotic residues in animal products, types of antibiotics, and their possible impact on human health in Africa. The literature search involved the use of a systematic survey using data that were published from Africa from 2015 to 2024. The search terms used the Boolean operators with keywords such as antibiotics, antibiotic residues, antibiotics in animal products in Africa, and impact on human health. Only research conducted in Africa was used in the present study. The findings showed that the most prevalent groups of antibiotic residues were aminoglycoside, macrolides, β-lactams, fluoroquinolones, tetracyclines sulfonamides, and phenicols. Tetracycline showed the most prevalent antibiotic residue with 43% mostly from East Africa, followed by sulfonamides at 19%, and β-lactams at 16%; most of the antibiotic residue levels were higher than the World Health Organization permissible limit. Noncompliance with withdrawal periods and maximum residue limits for antibiotics used in food-producing animals may lead to negative outcomes such as allergic reactions, teratogenicity, carcinogenicity, microbiome alterations, and, most notably, antibiotic resistance. As a result, there is a need for constant monitoring of antibiotic residues in animal products in addition to the consideration of alternatives to antibiotics in order to avoid their health implications.

This study assessed the awareness, understanding, and practices of household waste recycling in high-income and low-income communities in the North of Pretoria, South Africa. A structured questionnaire was administered through face-to-face interviews and a door-to-door survey. A purposive sampling involving 122 participants was carried out. Data were collected from September 2023 to April 2024 and analyzed using descriptive statistics and the Pearson chi-square test. The study area was divided into four sites (A, B, C, and D) based on income levels. At sites A, B, and C (low-income communities), 81.6%, 81.4%, and 75.0 % of participants, respectively, did not separate waste, whereas at Site D (high-income community), 61.5% of the participants did not separate their household waste before disposal. Participants from all the communities were aware of recycling in the following order: Site D (76.9%) >Site C (60.7%) >Site A (60.5%) >Site B (51.2%). However, actual recycling rates remained low, with only 30.7% of high-income and 15.8% to 20.1% of low-income participants partaking in recycling practices. Lack of time and inadequate infrastructure were identified as major obstacles to household waste recycling. Recycling was only carried out when there was a perceived financial benefit. Despite their knowledge of recycling, most participants did not recycle their household waste. Awareness campaigns and incentives ought to be introduced to encourage recycling and boost community participation. The establishment of local recycling centres could enhance engagement in recycling, resulting in employment opportunities.

Background: Artificial intelligence (AI) and digital technology, as advanced human-created tools, are influencing the healthcare sector.Aim: This review provides a comprehensive and structured exploration of the opportunities presented by AI and digital technology to laboratory diagnostics and management of communicable and non-communicable diseases in Africa.Methods: The study employed the Preferred Reporting Items for Systematic Reviews, Meta-Analyses guidelines and Bibliometric analysis as its methodological approach. Peer-reviewed publications from 2000 to 2024 were retrieved from PubMed®, Web of Science™ and Google Scholar databases.Results: The study incorporated a total of 1563 peer-reviewed scientific documents and, after filtration, 37 were utilised for systematic review. The findings revealed that AI and digital technology play a key role in patient management, quality assurance and laboratory operations, including healthcare decision-making, disease monitoring and prognosis. Metadata reflected the disproportionate research outputs distribution across Africa. In relation to non-communicable diseases, Egypt, South Africa, and Morocco lead in cardiovascular, diabetes and cancer research. Representing communicable diseases research, Algeria, Egypt, and South Africa were prominent in HIV/AIDS research. South Africa, Nigeria, Ghana, and Egypt lead in malaria and tuberculosis research.Conclusion: Facilitation of widespread adoption of AI and digital technology in laboratory diagnostics across Africa is critical for maximising patient benefits. It is recommended that governments in Africa allocate more funding for infrastructure and research on AI to serve as a catalyst for innovation.What this study adds: This review provides a comprehensive and context-specific analysis of AI’s application in African healthcare.