Updated project metadata. Environmental air pollution such as diesel smoke emission has been shown to have an adverse effect on human skin. Although epidemiological studies showing adverse effects such as oxidative stress-induced aging exists, studies showing the cellular and molecular response to such stress are rare. Using a primary skin keratinocyte model and TMT-based quantitative proteomics strategy, we studied the effects of chronic exposure to diesel particulate matter (DPE) and DPE vapor on the cellular proteome and the ability of a known anti-oxidant Vitamin E in ameliorating such changes. LC-MS3 analysis of DPE and/or its vapor exposed skin keratinocytes resulted in quantification of 4,490 proteins of which 201 and 374 proteins were significantly dysregulated (≥1.5 fold, p-value ≥0.05) in each condition, respectively. We observed distinct molecular alterations in chronic DPE and DPE vapor exposure models. Dysregulation of several cellular processes such as cell cycle and gene regulation, oxidative stress response proteins, skin barrier integrity and skin hydration were observed in both DPE and DPE vapor exposed cells.