Environmental pollutants, including particulate matter, ozone, and polycyclic aromatic hydrocarbons, represent significant factors that impair skin function and integrity. Exposure to these substances has been shown to induce reactive oxygen species formation, activate inflammatory pathways, and impair the epidermal barrier. Oxidative stress and chronic inflammation result in lipid imbalance, collagen degradation, increased transepidermal water loss, and dysregulation of immune responses. Clinically, this manifests as accelerated skin aging, pigmentation disorders, and exacerbation of inflammatory dermatoses such as atopic dermatitis, psoriasis, and acne vulgaris. However, the skin has many complex defence mechanisms, including antioxidant systems, lipid barrier repair processes, and immune regulation. The skin microbiome also plays an important role in maintaining homeostasis. Under chronic exposure, these mechanisms gradually become impaired, leading to persistent skin barrier dysfunction. Understanding the molecular basis of these processes is crucial for developing effective preventive and therapeutic strategies, including the use of antioxidants, Nrf2 pathway activators, and interventions that support the skin microbiome. Environmental pollutants should be recognized as an important modifiable risk factor for skin diseases and considered in routine dermatological practice.