Detailed answer

Air pollution, particularly fine particulate matter (PM2.5) and volatile organic compounds (VOCs), can harm the skin by generating reactive oxygen species (ROS) and free radicals, which cause oxidative stress. This oxidative stress damages collagen and elastin fibers in the skin, leading to decreased levels of these structural proteins. As a result, the skin loses its elasticity and firmness, leading to sagging skin. Additionally, air pollution can increase the production of matrix metalloproteinases (MMPs), enzymes that further degrade collagen and elastin. Furthermore, pollution particles can penetrate the skin, causing inflammation and disruption of the skin's barrier function, which further contributes to sagging skin. To protect against the impact of air pollution on the skin, it is essential to cleanse the skin thoroughly, use antioxidants, and apply a broad-spectrum sunscreen to minimize exposure to harmful pollutants.