Thesis (doctoral)--Universiteit van Amsterdam, 1990. / Summary also in Dutch. Includes bibliographical references.

Aims and objectives: The research aims and objectives of this thesis were: (i) to review literature pertaining to different dermal exposure assessment methods; (ii) to assess dermal exposure of refinery workers to nickel and/or cobalt by making use of skin wipes as a removal method; (iii) to assess concurrently the skin condition of the above mentioned workers by measuring skin hydration, transepidermal water loss (TEWL) and skin surface pH, and (iv) to compare South African skin notations and sensitisation notations with those of other developed countries. Methods: Refinery workers from two base metal refineries participated in this study. Skin condition and dermal exposure was measured on different anatomical areas before, during and at the end of a work shift. Dermal exposure to nickel and/or cobalt was assessed with Ghostwipes TM as a removal method. Wipe samples of potentially contaminated surfaces in the workplace were also collected. Wipes were analysed for nickel and/or cobalt according to NIOSH method 9102, using Inductively Coupled Plasma-Atomic Emission Spectrometry. The assignment and use of skin notations and sensitisation notations in South African legislation and six other developed countries were compared. Results: To date, occupational dermal exposure has been reported for numerous substances by making use of surrogate skin methods (interception methods), removal methods and fluorescent tracer methods (in situ detection methods). From published literature it is evident that skin (dermal) wipes, as a removal method, are the most appropriate method to assess dermal exposure to metals. Varying degrees of skin dryness (low hydration indices) and impaired barrier function (high TEWL indices) are reported, with the hands being implicated the most. However, normal skin condition is also reported for some anatomical areas. Skin surface pH for all anatomical areas sampled decreased significantly during the shift, but remained in normal range. Dermal exposure to nickel occurred during the shift at the electro-winning plant of one refinery, while dermal co-exposure to cobalt and nickel occurred at the cobalt plant of the other refinery. At both of the refineries, cobalt and/or nickel was collected from the workers’ skin even before the shift. Also, dermal exposure to these metals was highly variable between individual workers. Skin notations in South African legislation had a mean agreement of between 42.9% and 45.8% with other countries, while agreement for sensitisation notations was only 3.6% between countries. / Thesis (Ph.D. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2011.

The aims and objectives: The aims and objectives of this study were to characterize and compare the airborne particulate matter in the tankhouse and crusher areas of a base metal refinery sampled with two separate methods, in terms of mass concentration, nickel content, and particle size distribution. Methods: Area sampling was conducted in the two areas. Two methods were applied to collect particulate samples. The first is a multi–stage virtual impactor, the Respicon, which was used to determine the three critical particle fractions (inhalable, thoracic and respirable). The NIOSH 7300 method determined the particle concentration and nickel percentage present in each fraction. Using formulas provided by the manufacturers two additional particle–size fractions (extra–thoracic and trachea–bronchial) could be calculated. The second was based on the standard NIOSH 0500 method, which determined particle size distribution depicted as cumulative percentages. The samples were analyzed using laser scattering instrumentation. Results: In the tankhouse the highest level of exposure was to particles bigger than 10 um, with the highest nickel percentage also falling into this range. However, high nickel percentages were present in all three cut–off sizes (4 um, 10 um and > 10 um). The particle concentration for the crusher area was the highest for particulates bigger than 10 um, with the highest nickel percentage present in this fraction. After comparing the tankhouse and crusher areas, it is clear that the particle concentration is much higher in the crusher area according to all sampling methods used. The nickel content present in the analysis of these areas is of great concern. Conclusion: With the knowledge obtained through this research one hopes to establish a basis for particle size sampling in the platinum mining industry. This may lead to the development of health based OEL's and reflect a more accurate evaluation of workers particulate exposure. This information will give a greater understanding of health risks workers are exposed to. / Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2011.

Aims and objectives: The research aims and objectives of this thesis were: (i) to review literature pertaining to different dermal exposure assessment methods; (ii) to assess dermal exposure of refinery workers to nickel and/or cobalt by making use of skin wipes as a removal method; (iii) to assess concurrently the skin condition of the above mentioned workers by measuring skin hydration, transepidermal water loss (TEWL) and skin surface pH, and (iv) to compare South African skin notations and sensitisation notations with those of other developed countries. Methods: Refinery workers from two base metal refineries participated in this study. Skin condition and dermal exposure was measured on different anatomical areas before, during and at the end of a work shift. Dermal exposure to nickel and/or cobalt was assessed with Ghostwipes TM as a removal method. Wipe samples of potentially contaminated surfaces in the workplace were also collected. Wipes were analysed for nickel and/or cobalt according to NIOSH method 9102, using Inductively Coupled Plasma-Atomic Emission Spectrometry. The assignment and use of skin notations and sensitisation notations in South African legislation and six other developed countries were compared. Results: To date, occupational dermal exposure has been reported for numerous substances by making use of surrogate skin methods (interception methods), removal methods and fluorescent tracer methods (in situ detection methods). From published literature it is evident that skin (dermal) wipes, as a removal method, are the most appropriate method to assess dermal exposure to metals. Varying degrees of skin dryness (low hydration indices) and impaired barrier function (high TEWL indices) are reported, with the hands being implicated the most. However, normal skin condition is also reported for some anatomical areas. Skin surface pH for all anatomical areas sampled decreased significantly during the shift, but remained in normal range. Dermal exposure to nickel occurred during the shift at the electro-winning plant of one refinery, while dermal co-exposure to cobalt and nickel occurred at the cobalt plant of the other refinery. At both of the refineries, cobalt and/or nickel was collected from the workers’ skin even before the shift. Also, dermal exposure to these metals was highly variable between individual workers. Skin notations in South African legislation had a mean agreement of between 42.9% and 45.8% with other countries, while agreement for sensitisation notations was only 3.6% between countries. / Thesis (Ph.D. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2011.

The aims and objectives: The aims and objectives of this study were to characterize and compare the airborne particulate matter in the tankhouse and crusher areas of a base metal refinery sampled with two separate methods, in terms of mass concentration, nickel content, and particle size distribution. Methods: Area sampling was conducted in the two areas. Two methods were applied to collect particulate samples. The first is a multi–stage virtual impactor, the Respicon, which was used to determine the three critical particle fractions (inhalable, thoracic and respirable). The NIOSH 7300 method determined the particle concentration and nickel percentage present in each fraction. Using formulas provided by the manufacturers two additional particle–size fractions (extra–thoracic and trachea–bronchial) could be calculated. The second was based on the standard NIOSH 0500 method, which determined particle size distribution depicted as cumulative percentages. The samples were analyzed using laser scattering instrumentation. Results: In the tankhouse the highest level of exposure was to particles bigger than 10 um, with the highest nickel percentage also falling into this range. However, high nickel percentages were present in all three cut–off sizes (4 um, 10 um and > 10 um). The particle concentration for the crusher area was the highest for particulates bigger than 10 um, with the highest nickel percentage present in this fraction. After comparing the tankhouse and crusher areas, it is clear that the particle concentration is much higher in the crusher area according to all sampling methods used. The nickel content present in the analysis of these areas is of great concern. Conclusion: With the knowledge obtained through this research one hopes to establish a basis for particle size sampling in the platinum mining industry. This may lead to the development of health based OEL's and reflect a more accurate evaluation of workers particulate exposure. This information will give a greater understanding of health risks workers are exposed to. / Thesis (M.Sc. (Occupational Hygiene))--North-West University, Potchefstroom Campus, 2011.