Gladys Belle

Dr. Gladys Belle

orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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29 August 2023 in Water
Verified
Journal Article
Open access
PDF file
GBGladys Belle
Gladys Belle
Yolandi SchoemanYolandi Schoeman
Yolandi Schoeman
Paul OberholsterPaul Oberholster
Paul Oberholster
This study focused on assessing the extent of pollution in both flowing and non-flowing surface water within the Matjhabeng mining area of South Africa, with particular emphasis on the substantial impact of gold mine tailings. A comprehensive analysis of physical water-quality attributes, including potentially toxic elements (PTEs), and relevant pollution risk indices was undertaken. To comprehensively elucidate the potential risks to aquatic organisms and human health, a risk assessment framework predicated upon the source–pathway–receptor model was developed. Principal Component Analysis (PCA) was employed as a multivariate statistical tool to discern the potential origins of PTE contamination within the environment. The results substantiate pronounced pollution manifestations within the surface water milieu of the Matjhabeng mining area. Specifically, concentrations of critical PTEs, such as arsenic, cobalt, copper, iron, selenium, and zinc, exhibited transgressions of the regulatory thresholds stipulated by both the South African Department of Water Affairs and Forestry (DWAF) and the Canadian Council of the Ministers of the Environment (CCME). Additionally, concentrations of the aforementioned elements exceeded the stipulated DWAF guidelines for irrigation water usage. Pollution indices, encompassing the Single-Factor Pollution Index and the Nemerow Integrated Pollution Index, discerned moderate contamination stemming from As, while remarkably elevated pollution levels were identified for selenium. PCA elucidated 94.5% of the aggregate variance, revealing cobalt, copper, nickel, and zinc as coalescing within PC1, indicative of a common anthropogenic provenance that is conceivably linked to historical gold mine tailings. PC2 exhibited an aggregation of chromium, iron, and lead, reaffirming this shared anthropogenic etiology. The third PCA component was characterized by selenium, followed by arsenic and magnesium in the fourth. The resultant PTE contamination underscores a profound ecological and public health risk, impacting both the aquatic ecosystems and the local community within the precincts of the Matjhabeng Local Municipality (MLM) area, with consequential amplification of susceptibilities to deleterious health consequences. Urgent and concerted interventions are imperative to ameliorate the emergent decline in surface-water quality within the MLM locale. The adoption of nature-based remediation paradigms holds promise for efficaciously elevating water quality, ameliorating community health, and underpinning the long-term economic viability of the region.

24 August 2024 in Minerals
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Journal Article
Open access
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GBGladys Belle
Gladys Belle
Yolandi SchoemanYolandi Schoeman
Yolandi Schoeman
Paul OberholsterPaul Oberholster
Paul Oberholster
This research quantifies the health risks associated with exposure to heavy metals in the Matjhabeng Local Municipality, a gold mining region in South Africa, utilising a deterministic source–pathway–receptor approach. This study uniquely integrates both non-carcinogenic and carcinogenic risk assessments across multiple heavy metals, providing a comprehensive perspective on health impacts in mining-impacted communities. The study measured concentrations of arsenic (As), cadmium (Cd), lead (Pb), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), selenium (Se), and zinc (Zn) in soil samples, with mean values found to be 3.2 mg/kg, 2.5 mg/kg, 45 mg/kg, 17 mg/kg, and 25 mg/kg for As, Cd, Pb, Co, and Cr, respectively. The deterministic assessment revealed minimal non-carcinogenic risks for ingestion across all demographics (HQ < 1), while significant dermal risks were identified for Cd, Pb, Co, and Cr (HQ > 1), particularly for the adult group. The inhalation pathway emerged as a critical exposure route, with HQ values ranging from 5 to 15 and chronic hazard index values significantly exceeding safe limits (CHI > 5). The carcinogenic risk through inhalation notably surpassed the acceptable thresholds set by the United States Environmental Protection Agency (1 × 10−4 to 1 × 10−6), with a calculated lifetime cancer risk far exceeding the limit for As, Cd, Cr, Co, and Ni for both adults and juveniles. These findings underscore the urgent need for targeted risk mitigation strategies in the community to address the significant health risks posed by airborne heavy metal exposure.

29 September 2025 in Discover Applied Sciences
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Journal Article
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GBGladys Belle
Gladys Belle
BMBrenda Moodley
Brenda Moodley
RMRoshila Moodley
Roshila Moodley
Elizabeth OmotolaElizabeth Omotola
Elizabeth Omotola
CTChristoff Truter
Christoff Truter
Paul OberholsterPaul Oberholster
Paul Oberholster
The rising global demand for pharmaceuticals, especially during and after the COVID-19 pandemic, has intensified their presence in aquatic environments. These substances, often inadequately removed by conventional wastewater treatment processes, pose serious risks to aquatic ecosystems and human health due to their persistence, potential for bioaccumulation, and ability to induce antimicrobial resistance. While commonly used pharmaceuticals such as paracetamol and ciprofloxacin have been extensively studied, critical knowledge gaps remain for compounds like azithromycin, dexamethasone, and prednisone, despite their wide therapeutic use. This study presents a comprehensive review of the occurrence, detection techniques, and ecological risks of these three pharmaceuticals of emerging concern. Using literature sourced from peer-reviewed databases including Scopus, Web of Science, and Google Scholar, the review identifies significant gaps in current research, particularly regarding environmental monitoring in aqueous environments, transformation products, and long-term ecotoxicity. The review also discusses the limitations of existing analytical methods in detecting trace levels of these compounds. The scientific value of this work lies in its focus on understudied but environmentally relevant pharmaceuticals, providing a consolidated synthesis of fragmented data, and highlighting the urgent need for improved monitoring strategies. The study underscores the importance of expanding pharmaceutical surveillance to include these compounds and promoting the development of advanced detection technologies. Addressing these gaps is critical for protecting aquatic life, preventing the spread of resistant pathogens, ensuring water quality for human use, and fostering sustainable and resilient environmental management practices.

18 February 2024 in Water
Verified
Journal Article
Open access
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SMSekato Maremane
Sekato Maremane
GBGladys Belle
Gladys Belle
Paul OberholsterPaul Oberholster
Paul Oberholster
Rivers in Africa have experienced dire pollution as a result of the poor management of wastewater effluent emanating from water resource recovery facilities (WRRFs). An integrated wastewater resource recovery model was developed and applied to identify ideal wastewater resource recovery technologies that can be used to recover valuable resources from a mixture of wastewater effluents in a case study in the Burgersfort WRRF in the Limpopo province, South Africa. This novel model incorporates the process of biological nutrient removal (BNR) with an extension of conventional methods of resource recovery applicable to wastewater. The assessment of results of effluent quality from 2016 to 2022 revealed that ammonia, chemical oxygen demand, total coliform, fecal coliform, and Escherichia coli levels were critically non-compliant with the permissible effluent guidelines, indicating a stable upward trend in terms of concentrations, and scored a very bad wastewater quality index rating. All variables assessed showed a significant loading, except for orthophosphates, and significant correlations were observed among the variables. The results of the integrated wastewater resource recovery model revealed a high probability of reclaiming recoverable resources such as nutrients, sludge, bioplastics, biofuel, metals, and water from wastewater, which have economic, environmental, and social benefits, thereby improving the effluent quality of a WRRF.

15 October 2022 in Journal of Environmental Science and Health, Part A
Verified
Journal Article
Closed access
GBGladys Belle
Gladys Belle
POPaul Johan Oberholster
Paul Johan Oberholster
AFAnnabel Fossey
Annabel Fossey
LELeana Esterhuizen
Leana Esterhuizen
RMRoshilia Moodley
Roshilia Moodley
The presence of potentially toxic elements (PTEs) in soil and plants is a risk factor to human well-being and the environment. Soil and leaves from a traditional medicinal plant, Vachellia karroo, known as the sweet thorn plant, were assessed to determine the extent of pollution by PTEs from gold mine tailings in a case study area of Matjhabeng Local Municipality, South Africa. A risk classification tool was developed using the different indicators of pollution quantified to describe the pollution risk at each sampling site. High concentrations of copper, cadmium, lead, nickel, and zinc were measured in the soil, which exceeded the maximum permissible soil quality limits. The enrichment factor and geoaccumulation index results also confirmed heavy soil pollution by copper, nickel, and zinc, with exceptionally heavy pollution by cadmium and selenium. The PTEs in the soil were in an exchangeable form, with the sweet thorn plant accumulating lead and selenium at toxic levels, which poses a risk to the health of the local people as the plant is used for medicinal purposes. The overall pollution risk classification tool of the sampling sites showed that 17% were high-risk areas, 53% were moderate-risk areas, and 20% of the sites were low-risk areas.

9 December 2018 in Water and Environment Journal
Verified
Journal Article
Closed access
PDF file
GBGladys Belle
Gladys Belle
AFAnnabel Fossey
Annabel Fossey
LELeana Esterhuizen
Leana Esterhuizen