Traffic-derived air pollution compromises skin barrier function and stratum corneum redox status: A population study.

Background Since air pollution is only one of many environmental stressors that can affect skin, it has been challenging to identify skin appearance or functional features profoundly affected by chronic exposure to traffic-derived air pollution. Aims The current population study focused on taxi drivers working in urban and rural areas in order to take advantage of difference in occupational exposure. Methods The skin conditions of 100 middle-aged male taxi drivers from urban Shanghai and 66 from rural Chongming were measured with facial tape strips were collected for biomarker analyses. Results Trans-epidermal water loss (TEWL) values before and after tape stripping were considerably higher in urban taxi drivers from Shanghai. Contrary to previous studies, there was no apparent detrimental effect on skin wrinkle or pigmentation from traffic pollution, which might be attributed to the higher than general public level of photo-exposure in this population. At the same time, pollution exposure especially the heavy traffic pollution exposure was found to associate with lower stratum corneum trypsin-like enzyme activity (SCTE), reduced catalase activity and total antioxidant capacity (TAOC) in tape strips. Conclusion The evidence suggests that traffic-derived air pollution could deteriorate skin's physical and antioxidant barrier, whereas factors like photo-exposure can be overwhelming against appearance aging. Therefore, in addition to photoprotection, skin barrier care should be considered for people with high air pollution exposure.