DSpace Repository

Welcome to the NWU Repository, the open access Institutional Repository of the North-West University (NWU-IR). This is a digital archive that collects, preserves and distributes research material created by members of NWU. The aim of the NWU-IR is to increase the visibility, availability and impact of the research output of the North-West University through Open Access, search engine indexing and harvesting by several initiatives.

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Recent Submissions

Equipment profile of South African Occupational Hygiene Approved Inspection Authorities
(North-West University, 2025) Engelbrecht, A; van der Merwe, C; Franken, A
Title: Equipment profile of South African Occupational Hygiene Approved Inspection Authorities The right to safe and harm-free working environments is provided for by the Bill of Rights, and reinforced by key legislative acts, such as the Mine Health and Safety Act 29 of 1996 and the Occupational Health and Safety Act 85 of 1993 (OHS Act). The OHS Act, in particular, mandates employers to maintain workplaces that are free from hazards, ultimately requiring the appointment of occupational hygiene professionals to uphold health and safety standards (SANS 2012:2). Specialised in hazard monitoring, Approved Inspection Authorities (AIAs) are sanctioned by the Chief Inspector to perform certified health and safety assessments. Their authorisation and approval are based on their strict adherence to the national standards set by the South African National Accreditation System. These standards outline the personnel, facilities, and equipment requirements. The extent of an AIA’s regulatory framework, or the different regulated hazards an AIA is allowed to assess, is based on the AIA's knowledge, expertise, and the appropriateness of their equipment. To guide AIAs, the Department of Employment and Labour (DoEL) published a list of equipment that highlights the types of equipment AIAs should use to assess the applicable hazards within their regulatory frameworks (SANS, 2012:5; SANAS, 2012:12). While the DoEL's equipment list outlines the basic equipment AIAs can retain for approval, staying up to date with rapidly advancing technology can be challenging for both new and more experienced AIAs. Equipment proliferation also affects the curricula of educational institutions, which aim to provide students with fit-for-purpose training.This raises an important question: What equipment is currently used by occupational hygiene AIAs, and why is it important? There are two main reasons why these questions matter. First, AIAs face a dual challenge. While trying to ensure competency, accuracy, and validity in their occupational hygiene operations, AIAs are also required to stay up to date with the latest technological advancements (SANS, 2023:12). Second, occupational hygiene students need to receive training that prepares them for real-world situations, and that is aligned with industry needs (Alanazi & Benlaria, 2023:5). The selection of equipment available on the market requires AIAs to choose the instruments based on their prioritised needs and the available information about this equipment. But, although manufacturers provide literature, the benefits, and capabilities of their equipment, the information Since the DoEL’s equipment recommendations were last updated in 20121, gathering the necessary information to make informed equipment decisions can be difficult. This can be particularly challenging for new AIAs trying to choose the right equipment. To address these challenges, a practical solution involved creating an equipment profile of national AIAs. This detailed profile aimed to identify the prevalent equipment and methodologies used by industry professionals. By identifying these prevalences, AIAs can have a reference point for comparison, and educational institutions can tailor their curricula to ensure fit-for-purpose training aligned with industry needs. This initiative aims to streamline the transition of occupational health and hygiene graduates into the workforce and provide clarity for companies, especially startups, seeking guidance on acquiring equipment that is both effective and in line with industry expectations. Employing a mixed methods research approach of sequential exploratory design, registered occupational hygienists — each representing one of the 53 registered Type A AIAs, and whereof only 11 responded to the questionnaire — were invited to an online survey. This survey was created and administered using the Google Forms platform and required AIAs to answer questions pertaining to the equipment and methods they currently employ for hazard monitoring. After doing a data analysis of the number of equipment, the most frequently selected equipment models, and brands, the popularity of instruments was calculated based on the number of times selected as well as the number of units currently used. The calibration frequencies, buying drivers, and hazard evaluation methods were also investigated. The quantitative data was then used to assist with the interpretation of qualitative data. These findings were reported as the representing equipment profile of participating AIAs. Findings showed the consistent preference participating AIAs had for user-friendly, reliable, and cost-effective monitoring equipment. Highlighting the importance of equipment practicality. Differences in the calibration practices, however, emphasises the need for clear guidelines on the external calibration frequency necessary for all equipment. While the most prevalent equipment and methods were established, these findings also reinforce how academic curricula can bridge the gap between the current and prospective industry-needs. AIAs need in order to make informed decisions are not as readily available (AIHA, 2017) Educational institutions can update their equipment inventories by incorporating both prevalent, and less popular equipment types while also enhancing students’ technical skills through the adoption of both old and new equipment models. This could prepare students for real-world challenges, encourage work-readiness, and ensure their curricula aligns with industry-needs. While this study had a few limitations, it still provides occupational health and hygiene professionals with a detailed equipment profile of AIAs currently in practice. However, the lack of participation may affect the representativeness of this profile since only 11 of the 53 recruited AIAs participated. The potential biases from self-reported data could also affect the accuracy of these results. Future studies are, therefore, encouraged to combine questionnaires with interviews or direct observations. This mixed-methods approach could help verify self-reported data and enhance its accuracy. While consulting with industry experts during the design process could ensure even more comprehensive data to be collected. Word count: 882
Performance comparison of the Nanozen Dustcount personal real-time monitor with a conventional respirable dust exposure sampling method
(North-West University, 2025) Jansen, V; Van Der Merwe, CJ; Linde, SJL
Title: Performance comparison of the Nanozen DustCount personal real-time monitor with a conventional respirable dust exposure sampling method Introduction: The mining industry, a vital contributor to many economies, particularly in South Africa, poses significant health risks due to dust exposure. Dust from mining operations varies in composition and particle size, influencing its health impacts. Safeguarding workers' health has been a legislated priority since 1911, with legislation mandating exposure monitoring and the implementation of control measures. Conventional gravimetric sampling is the most widely used and accepted standard for air monitoring, using a pump and filter system to collect samples in a worker's breathing zone over a shift. Although reliable, this method involves gravimetric analysis of the filter in a laboratory, which delays results and limits timely interventions. Advancements in technology and the development of direct-reading instruments, such as the Nanozen DustCount® 9000-Z1 personal real-time monitor (Nanozen Industries Inc., Vancouver, Canada), provide faster, real-time dust exposure measurements. The accuracy of these devices must, however, be validated against conventional gravimetric methods, such as the Methods for the Determination of Hazardous Substances (MDHS14/4) method, to ensure their reliability. A limited number of published studies have evaluated the performance of the DustCount, and even fewer assessed the performance of the DustCount through collecting samples side-by-side with conventional gravimetric sampling methods in a work environment. Method: This study evaluated the performance of the DustCount device compared to a conventional gravimetric sampling method through quantitative analyses of secondary data. The data was collected by a company contracted to conduct exposure monitoring in various areas of an open-cast iron ore mine in the Northern Cape, South Africa. A dataset of 35 paired results from side-by-side monitoring was analysed. The real-time respirable dust concentration results obtained from the DustCount’s optical particle counter were compared to those obtained using a cyclone following MDHS14/4, a conventional gravimetric sampling method. Additionally, the respirable dust concentration results from the DustCount’s optical particle counter were compared to those collected by the DustCount’s impactor and filter. Lastly, the respirable dust concentrations determined by the DustCount’s impactors were compared to those obtained using the cyclone following the MDHS14/4 method. Results: The geometric mean of the conventional gravimetric concentration (CGC) dataset was 0.416 mg/m³, with a coefficient of variance (CV) of 175%. In contrast, the DustCount real-time concentration (DRC) dataset had a lower geometric mean of 0.172 mg/m³ and a CV of 111%.Across all samples, the CGC method consistently reported higher respirable dust concentrations than the DRC method. Bland-Altman (BA) analysis confirmed that the DustCount underestimated respirable dust concentrations, with a mean bias of −71.41%, standard deviation (SD) of 35.17%, and 95% limits of agreement ranging from −166.6% to 11.84%. This significant underestimation highlights a key limitation of the DustCount for precise exposure quantification. Conclusion: The significant bias of −71.41% suggests that the DustCount instrument is inaccurate in measuring respirable dust concentrations, as it consistently underestimates values compared to the reference method. The large standard deviation of 35.17% and the wide limits of agreement (ranging from −166.6% to 11.84%) indicate a lack of precision, suggesting that the DustCount provides inconsistent measurements when compared to the reference method. Despite these limitations, the findings suggest that the DustCount has potential value as a realtime monitoring tool, as it does reflect temporal changes in respirable dust concentrations. With further refinement — particularly regarding the ease with which correction factors can be established — the instrument’s real-time capabilities could facilitate immediate interventions and enhance workplace safety by providing near instantaneous feedback. Word count: 535
Exploring the research approaches of South African researchers in psychology: Question-led or methodled?
(North-West University, 2025) Ras, JM; de Klerk, W; de Klerk, E
This research study explored whether South African researchers in psychology adopt a question-led or method-led approach in their research. It emphasised that selecting methods based solely on familiarity or preference can undermine the coherence of the research process. Instead, the research question should guide the choice of methodology, methods and data sources to ensure alignment and rigour. In light of South Africa's unique socio-cultural context and historical challenges, such as limited resources and a legacy of inequality in education and healthcare, the study also aimed to understand how these factors might influence the adoption of question-led or method-led approaches in psychological research. A qualitative research approach with a case study design was used. Participants were recruited using purposive and snowball sampling, and data was gathered through a qualitative online survey with open-ended questions. Fourteen academic researchers from various South African tertiary institutions wereincluded in the research study, offering insights into their research practices. Conventional content analysis was used to analyse the data. The research study found that most participants (85.7%) followed a question-led approach, highlighting the importance of tailoring methodologies to the research questions. The participants conveyed that the research question should be the foundation of the research process. They also stressed the importance of choosing methods that are well-suited to both the nature of the research question and the aim of the study, as this ensures the quality and rigour of the research. Additionally, the participants emphasised the pivotal role of formulating the research problem and question properly. These findings demonstrate the value of adopting question-driven research practices to enhance the relevance and impact of psychological research. The research study provides foundational insights for researchers and educators, promoting the integration of methodological adaptability and question-led inquiry in future research.
Thermal characterisation of the furnace tap floor environment of a platinum group metals smelter
(North-West University, 2025) van der Merwe, CJ; van der Merwe, CJ
Title: Thermal characterisation of the furnace tap floor environment of a platinum group metals smelter. Background: South Africa is the leading global producer of platinum group metals (PGMs), a vital industry that relies on high-temperature smelting processes. The smelting of PGM ore occurs in furnaces operating at extreme temperatures of 1350–1600°C, which generate significant radiant heat. Molten materials, released from the furnace during furnace tapping, pose an additional source of radiant heat. This intense thermal environment creates substantial risks of heat stress for workers performing tasks on the furnace tap floors. Despite the critical role these areas play in smelting operations, the thermal environment of furnace tap floors at PGM smelters remains poorly characterised. Understanding these conditions is essential for improving workersafety and informing the design of effective protective equipment. Objectives: To quantify various environmental variables (heat flux, dry-bulb temperature [DBT], wet-bulb temperature [WBT], globe temperature [GT], relative humidity [RH], wet-bulb globe temperature [WBGT] and air velocity) on the matte and slag tap floors, to assess and compare the spatial variation of the thermal variables within and across the tap floors, and to compare the heat flux and WBGT values to reference values. Method: Environmental variables were measured across a grid on the matte and slag tap floors at a PGM smelter during normal tapping conditions. Environmental monitoring instruments, including heat stress monitors and a thermal comfort measurement system, were used to quantify heat flux, DBT, WBT, GT, RH and indoor wet-bulb globe temperature (WBGTi) on the tap floors. Contour maps of the thermal variables were generated using Surfer® software to assess spatial variations. Observations were made regarding the tappers’ duration of presence in various locations, activity levels and clothing. This information was used to estimate the time-weighted average effective WBGT (TWA-WBGTeff) values according to the ISO 7243 standard for various exposure scenarios. Heat flux exposure at various locations was estimated and compared to the recommended maximum durations for aluminised clothing. Results: The following mean levels of thermal variables were measured on the slag tap floor: 35.6 ± 3.6°C (DBT), 22.1 ± 1.9°C (WBT), 50 ± 10.4°C (GT), 16.2 ± 5.5% (RH), 29 ± 3.7°C (indoor wet-bulb globe temperature [WBGTi]) and 974 ± 537 W/m² (heat flux). The matte tap floor exhibited the following levels of these variables: 35.8 ± 3.1°C (DBT), 20.8 ± 1.8°C (WBT), 48.5 ± 9.2°C (GT), 11.1 ± 2.3% (RH), 27.8 ± 3.2°C (WBGTi) and 554 ± 458 W/m2 (heat flux). Hotspotson the matte tap floor were observed surrounding the active tap-hole and launder, whereas the slag tap floor exhibited a hotspot at the centre front and cooler regions at the sides. A moderate to strong and statistically significant correlation was observed between WBGT and heat flux on both the matte (rs(15) = 0.68, p = 0.006) and slag tap floors (rs(19) = 0.67, p = 0.002). The TWAWBGTeff exceeded their respective limits in all scenarios except when only 20 minutes per hour was spent on the tap floors. The heat flux levels at various locations (< 4600 W/m2) did not exceed the exposure durations since no maximum exposure duration is recommended at this heat flux level. Conclusion: The matte and slag tap floors present distinct and non-uniform thermal environments with spatially varying conditions. On the matte tap floor, heat is concentrated around the active launder while the slag tap floor presents a more balanced thermal environment, reflecting the difference in tapping practices between the floors. The correlation between heat flux and WBGT suggests future research regarding its potential as a proxy for conventional heat stress metrics. Elevated thermal conditions are present on the tap floors that pose a risk of heat stress to furnace tappers depending on location and exposure duration. More than 20 minutes per hour on the tap floor when wearing an aluminised suit poses a risk of heat stress to furnace tappers. These findings could inform future workplace interventions by identifying high-risk areas and understanding the factors contributing to heat stress, enabling more targeted and effective strategies to protect furnace tappers
The influence of two alcohol-based hand rubs on skin barrier function of black African female students
(North-West University, 2025) Uren, CA; Franken, A; Ramotsehoa, MC; Du Plessis, JL
Effective hand hygiene remains paramount in infection and prevention programmes. Healthcare workers have an increased prevalence of skin irritation owing to frequent hand hygiene practices. Alcohol-based hand rubs (ABHRs) are often recommended for hand hygiene practices due to their effectiveness, practicality, and safety profile. Research comparing the effects of detergent soaps and ABHRs on skin conditions is abundant; however, it is limited to Caucasian populations. Current research strongly favours disinfection by ABHRs over detergent soaps as they are better tolerated. Aim: This study aims to assess and compare the acute effects of ethanol-based and isopropyl-based hand rubs on skin barrier function in a black African female population, a demographic that is often underrepresented in skincare research. Method: Thirty female African students with Fitzpatrick skin type V or VI, not suffering from any pre-existing skin pathology in the age range of 20-30 years, participated in the study. Two ABHR interventions were applied to randomised sampling sites on the volar forearm of the non-dominant arm at six measurement intervals over eight hours. Skin barrier function was assessed by standardised measurements such as transepidermal water loss (TEWL), stratum corneum hydration (SCH), and skin surface pH (SS-pH). Results: None of the ABHR interventions caused significant changes in TEWL, while SCH levels improved, particularly with ABHR1, indicating superior moisturising properties. Additionally, both ABHRs reduced SS-pH to a slightly acidic level, which is beneficial for skin barrier protection and repair. Conclusion: Both ABHRs (ethanol- and isopropyl-based) were well tolerated by the skin and did not disrupt the skin barrier of an African female population when applied acutely over eight hours.