Pollution protection and the skin – testing strategies
Solar UVR, noxious gases, particulate matter, ozone, and cigarette smoke are key air pollutants with subsequent negative effects on the skin. Cigarette smoking is associated with skin aging (wrinkles, skin dryness, skin discoloration and so on), and the combination of smoking and solar UVR may even exacerbate the skin aging processes. In this paper we describe a new validated clinical method to evaluate the “protective” effects of specific cosmetic products against gaseous pollution exposure based on cigarette smoke as a pollutant model. The skin of human volunteers is treated with the product under test, exposed to cigarette smoke and then peroxidation of human sebum or skin barrier lipids is assessed using GC-MS/ LC-MS. Key advantages of this method is the small number of volunteers required, and the reproducibility and sensitivity of the method to detect protective and anti-oxidative properties of cosmetic active ingredients and cosmetic formulations. Pollutant cigarette smoke is a suitable substance containing all key pollution components that can be used in human volunteers without ethical issues as compared to other pollution sources. Furthermore, our method enables us to induce under standardized clinical laboratory conditions a pollution stress on “living skin”.
According to the World Health Organisation (WHO), more than 80% of people living in urban areas are exposed to air quality levels that exceed WHO limits (1). Ambient air pollution, made of high concentrations of small and fine particulate matter, is the greatest environmental risk to health—causing more than 3 million premature deaths worldwide every year (1).
Human skin is exposed to ultraviolet radiation (UVR) and environmental air pollutants such as polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), oxides, particulate matter (PM), ozone (O3), and cigarette smoke (2, 3). Consequently, the continual increase in air pollution is having major negative effects, and although the skin shields against pollution, prolo