Transepidermal water loss, stratum corneum hydration, and skin surface pH of female African and Caucasian nursing students.

BACKGROUND: Conflicting evidence exists on how skin barrier function compares between Africans and Caucasians. This study measured skin barrier function of South African first year nursing students before their practical training started to compare skin barrier function between the racial groups. METHODS: Transepidermal water loss (TEWL), stratum corneum (SC) hydration, and skin surface (SS) pH was measured on female first year nursing students (19 African and 31 Caucasian; age range 18-40 years). Geometric means and ranges were calculated and the influence of anatomical areas and racial differences were evaluated respectively. RESULTS: No significant difference in TEWL was established between the racial groups. SC hydration was significantly lower (P ≤ 0.05) and SS-pH was significantly higher (P ≤ 0.0001) in African nursing students when compared to Caucasians. African nursing students had significantly lower (P ≤ 0.05) SC hydration on their palms when compared to the other anatomical areas. CONCLUSION: Stratum corneum hydration and SS-pH differed significantly between African and Caucasian skin, while no difference was found for TEWL, the primary parameter used to evaluate skin barrier function. Low SC hydration and high SS-pH of African nursing students prior to their practical training, may suggest a higher risk for developing occupational skin diseases.

A retrospective analysis of nickel exposure data at a South African base metal refinery.

This study aimed to analyze historical soluble nickel exposure data from a South African base metal refinery and to identify trends in the soluble nickel exposure from 1981 until 2014 in the electrowinning department. Exposure data were presented in an exposure matrix, which described exposure profiles for both area and personal exposures inside two tankhouses. Exposure data were standardized by converting total nickel aerosol concentrations to inhalable nickel concentrations (correction factor 3.0). One-way analyses of variances (ANOVA) were conducted to identify significant differences in log-transformed area and personal exposures from 1982 until 2014, and the trends were assessed with linear regression. Differences were evaluated in area exposure between sections inside the tankhouses, i.e., East, West, and Center bays and in personal exposure between occupations, i.e., cell workers, crane drivers, and supervisors. Area exposure in Tankhouse 1 declined significantly (p ≤ 0.0001) between 1982 and 1986 with a factor of 29. However, after 1986 no significant downward trend in area exposure was evident in Tankhouse 1. Personal exposures in Tankhouse 1 significantly (p ≤ 0.0001) decreased with a factor of three between 1991 and 2014. No significant trends were evident in area and personal exposure in Tankhouse 2. Downward exposure trends were evident in Tankhouse 1 and may be ascribed to the implementation of various control measures and process changes, e.g., increasing polypropylene bead load. Limited data were available for Tankhouse 2, therefore, no trend in exposure could be established. Retrospective analyses may be used to identify trends and anomalies in exposure which might not have been identified during daily exposure monitoring.