How does UV radiation primarily damage the skin?

The primary way UV radiation damages the skin is by leading to premature aging and increasing the risk of skin cancer. UV rays penetrate the skin and cause changes at the cellular level, resulting in the breakdown of collagen and elastin, which are vital for maintaining skin's elasticity and firmness. This breakdown accelerates the aging process, contributing to wrinkles, sagging, and other signs of skin deterioration commonly associated with photoaging.

Moreover, the DNA damage inflicted by UV exposure is a key factor in the development of skin cancers, including melanoma, basal cell carcinoma, and squamous cell carcinoma. Prolonged exposure to ultraviolet radiation can result in mutations in the skin cells that may eventually lead to uncontrolled cell growth—the hallmark of cancer.

While reddening of the skin and sunburns are certainly consequences of UV exposure, they are more immediate effects rather than the primary long-term damages. Skin allergies can occur from various factors, including products or irritants, and are not directly caused by UV radiation. Therefore, understanding the comprehensive impact of UV rays on skin health illustrates why the statement about premature aging and increased cancer risk accurately reflects the primary damage caused by UV radiation.