The influence of occupational exposure to sulphuric acid mist on skin barrier function in a base metal refinery / Nicolas Christoph Meyer

• Main Author: Meyer, Nicolas Christoph
• Language: en
• Published: 2014
• Online Access: http://hdl.handle.net/10394/11190

Motivation: The skin is the primary barrier between the internal and external environment. Damage to this barrier will lead to adverse health effects such as water loss through the skin as well as the absorption of exogenous and potentially hazardous substances. The monitoring of employees’ skin condition is not yet seen as feasible in the field of Occupational Hygiene, this study should shed some light on its importance. Aim: To determine the extent of the possible negative influence of sulphuric acid mist on the skin condition and skin barrier function of employees working at a base metal refinery, by assessing the concentrations of sulphuric acid mist in the air and correlating it to three skin variables. These three variables are transepidermal water loss (TEWL), hydration of the skin and skin surface pH. Consequently the correlation between pH and TEWL, pH and hydration and TEWL and hydration, will also be investigated. Methodology: The concentration of sulphuric acid mist present in the air of the copper- and nickel tank houses was measured using NIOSH method 7903 for inorganic acids. Measurements of the skin barrier function were also done to determine the state of the skin condition at that time. Three variables were measured, namely TEWL, stratum corneum hydration and skin surface pH. The sulphuric acid mist concentrations were then correlated with the skin values to determine the influence of sulphuric acid mist on the skin barrier function. Qualitative swab samples were taken on the test subjects to determine if copper or nickel was present on the skin or not. This was done for two reasons: Firstly, if copper or nickel is present on the skin, these metals could have been absorbed into the skin and contributed to the skin being damaged. Secondly, if the skin variables show that skin damage has occurred on these workers, there might be higher possibility that these metals will be absorbed through the skin which could have adverse health effects. Results and conclusions: The results of this study indicated that the palm of hand and back of hand areas showed high TEWL values and low hydration values. This is to be expected as these areas are subjected to mechanical friction by PPE leading to wear and tear on the skin surface. Few meaningful correlations could be drawn between the sulphuric acid mist concentrations encountered in the tank houses and the three measured skin variables. It is therefore concluded that the low level of sulphuric acid mist in the atmosphere had no detectable effect on the skin barrier function. However, it was clear that nickel tank house workers showed higher TEWL values and lower hydration values than copper tank house workers, albeit copper tank house workers are exposed to higher sulphuric acid concentrations than nickel tank house workers, which in turn supports the conclusion mentioned above. The deteriorated skin barrier function seen in nickel tank house workers can therefore be attributed to the presence of nickel on the workers’ skin, a well-known skin sensitiser. === MSc (Occupational Hygiene), North-West University, Potchefstroom Campus, 2014