Browsing by Author "10101268 - Du Plessis, Johannes Lodewykus"
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Assessing a portable, real‐time display handheld meter with UV‐A and UV‐B sensors for potential application in personal sun exposure studies
Du Preez, D.J.; Du Plessis, J.L.; Wright, C.Y. (Wiley, 2018)Background Observing accurate real‐time measurements of solar ultraviolet radiation (UVR) levels is important since personal excess sun exposure is associated with skin cancers. Handheld measurement devices may be helpful ... -
Assessment of dermal exposure and skin condition of workers exposed to nickel at a South African base metal refinery
Du Plessis, Johannes L.; Eloff, Frederik C.; Badenhorst, Casper J.; Olivier, Johretha; Laubscher, Petrus J.; Van Aarde, Michiel N.; Franken, Anja (Oxford Univ Press, 2010)Objectives: The objectives of this study were to assess dermal exposure of cell workers to nickel at a South African base metal refinery and to characterize their skin condition by measuring the skin hydration and trans ... -
Associations of outdoor fine particulate air pollution and cardiovascular disease in 157 436 individuals from 21 high-income, middle-income, and low-income countries (PURE): a prospective cohort study
Hystad, Perry; Du Plessis, Johan L.; Larkin, Andrew; Rangarajan, Sumathy; AlHabib, Khalid F. (Elsevier, 2020)Background Most studies of long-term exposure to outdoor fine particulate matter (PM2·5) and cardiovascular disease are from high-income countries with relatively low PM2·5 concentrations. It is unclear whether risks are ... -
Back to basics the skin barrier and how it is affected in common occupational scenarios
Du Plessis, Johannes Lodewykus; Eloff, Frederik Christoffel; Du Plessis, Johannes Lodewykus; Eloff, Frederik Christoffel (Occupational Health Southern Africa, 2010) -
Biometrology guidelines for the in vivo assessment of skin surface pH in nonclinical settings
Stefaniak, Aleksandr B.; Du Plessis, Johan L. (Springer, 2017)Skin surface pH plays an important role in the maintenance of skin barrier integrity and epidermal homeostasis. In workplace environments, myriad exposures may alter the skin surface pH and influence development of skin ... -
Biometrology guidelines for the in vivo assessment of transepidermal water loss and skin hydration in nonclinical settings
Du Plessis, Johan L.; Stefaniak, Aleksandr B. (Springer, 2017)It is becoming evident that assessment of skin exposure to physical and chemical stressors in workplaces should be accompanied by the assessment of skin barrier function at the time of exposure. “Real-life” occupational ... -
Comparison of South African skin and sensitisation notations with those of other countries
Du Plessis, Johannes Lodewykus; Eloff, Frederik Christoffel; Franken, Anja; Laubscher, Petrus Johannes; Van Aarde, Michiel Nicolaas (Occupational Health Southern Africa, 2010)South African skin notations listed in the Regulations for Hazardous Chemical Substances (RHCS) and Mine Health and Safety Regulations (MHSR) were compared to those of selected other developed countries in order to ascertain ... -
Dermal exposure and changes in skin barrier function of base metal refinery workers co-exposed to cobalt and nickel
Du Plessis, J.L.; Eloff, F.C.; Engelbrecht, S.; Laubscher, P.J.; Van Aarde, M.N.; Franken, A. (The South African Society of Occupational Medicin, 2013)Refi nery workers are exposed to many metals, including cobalt and nickel, both of which are skin sensitisers, causing allergic contact dermatitis. Dermal exposure, and changes in skin barrier function [skin hydration, ... -
Diffuse reflectance spectroscopy versus Mexameter® MX18 measurements of melanin and erythema in an African population
Wright, Caradee Y.; Du Plessis, Johan; Karsten, Aletta E.; Wilkes, Marcus; Singh, Ann (Wiley, 2016)Melanin provides protection against excess exposure to solar ultraviolet radiation (UVR) and related adverse health effects. Diffuse reflectance spectroscopy (DRS) can be used to calculate cutaneous melanin and erythema, ... -
DNA damage and repair capacity in hairdressers exposed to chemical products: a pilot study
Eloff, F.C.; Preston, R.; Pretorius, P.J.; Du Plessis, J.L.; Laubscher, P.J.; Van Aarde, M.N.; Van der Westhuizen, F.H.; Franken, A. (SASOM, 2013)Hairdressers are exposed to numerous hazardous chemical substances, some of which are known or suspected allergens, carcinogens or organic solvents. The objectives of this study were to compare DNA damage and DNA repair ... -
DNA damage and repair detected by the comet assay in lymphocytes of African petrol attendants: a pilot study
Keretetse, G.S.; Laubscher, P.J.; Du Plessis, J.L.; Pretorius, P.J.; Van der Westhuizen, F.H.; Van Deventer, E.; Van Dyk, E.; Eloff, F.C.; Van Aarde, M.N.; Du Plessis, L.H. (Oxford Univ Press, 2008)Petrol attendants are exposed to petrol volatile organic compounds (VOCs) which may have genotoxic and carcinogenic effects. The single-cell gel electrophoresis assay (comet assay) is a method highly sensitive to DNA damage ... -
Evaluation of emissions and exposures at workplaces using desktop 3-dimensional printers
Stefaniak, A.B.; Du Preez, S.; De Beer, D.J.; Du Plessis, J.L.; Johnson, A.R. (Elsevier, 2019)There is a paucity of data on additive manufacturing process emissions and personal exposures in real-world workplaces. Hence, we evaluated atmospheres in four workplaces utilizing desktop “3-dimensional” (3-d) printers ... -
Exposures during industrial 3-D printing and post-processing tasks
Du Preez, Sonette; Linde, Stephanus J.L.; Du Plessis, Johan; Johnson, Alyson; LeBouf, Ryan F. (Emerald, 2018)Purpose This paper aims to measure exposures to airborne contaminants during three-dimensional (3-D) printing and post-processing tasks in an industrial workplace. Design/methodology/approach Contaminant concentrations ... -
Flow cytometric analysis of the oxidative status in human peripheral blood mononuclear cells of workers exposed to welding fumes
Du Plessis, Lissinda; Laubscher, Petrus; Jooste, Jacques; Du Plessis, Johan; Franken, Anja; Van Aarde, Nico; Eloff, Fritz (Taylor & Francis, 2010)Flow cytometry is a simple analytical technique that identifies, counts, and characterizes cells. The oxidative status of cells is influenced by many exogenous sources, such as occupational exposure to welding fumes. This ... -
Health effects of household solid fuel use: findings from 11 countries within the prospective urban and rural epidemiology study
Hystad, Perry; Du Plessis, Johan L.; Duong, Mylinh; Brauer, Michael; Larkin, Andrew (EHP, 2019)Background: Household air pollution (HAP) from solid fuel use for cooking affects 2.5 billion individuals globally and may contribute substantially to disease burden. However, few prospective studies have assessed the ... -
In multiple situational light settings, visual observation for skin colour assessment is comparable with colorimeter measurement
Wright, C.Y.; Du Plessis, J.L.; Wilkes, M.; Reeder, A.I.; Albers, P.N. (Wiley, 2016)Background Finding inexpensive and reliable techniques for assessing skin colour is important, given that it is related to several adverse human health outcomes. Visual observation is considered a subjective approach ... -
In vitro permeation of metals through human skin: a review and recommendations
Franken, Anja; Eloff, Frederik C.; Du Plessis, Jeanetta; Du Plessis, Johannes L. (American Chemical Society, 2015)During the last few decades, the interest in skin permeation of, specifically, metals has increased with the in vitro method utilizing diffusion cells as the prominent method of investigating permeability. This review ... -
In vitro permeation of platinum and rhodium through Caucasian skin
Franken, A.; Eloff, F.C.; Du Plessis, J.; Badenhorst, C.J.; Jordaan, A.; Du Plessis, J.L. (Elsevier, 2014)During platinum group metals (PGMs) refining the possibility exists for dermal exposure to PGM salts. The dermal route has been questioned as an alternative route of exposure that could contribute to employee sensitisation, ... -
In vitro permeation of platinum through African and Caucasian skin
Franken, A.; Eloff, F.C.; Du Plessis, J.; Badenhorst, C.J.; Du Plessis, J.L. (Elsevier, 2015)The majority of the South African workforce are Africans, therefore potential racial differences should be considered in risk and exposure assessments in the workplace. Literature suggests African skin to be a superior ... -
Inflammation as possible mediator for the relationship between lung and artirial function
Van Rooyen, Yolandi; Schutte, Aletta E.; Huisman, Hugo W.; Eloff, Fritz C.; Du Plessis, Johan L.; Kruger, Annamarie; Van Rooyen, Johannes M. (Springer, 2016)Introduction Reduced lung function is associated with a risk for the development of cardiovascular disease. This association may be due to chronic inflammation which is often present in those with reduced lung ...