"Can dying hair lead to cancer, especially for those with graying hair?"

Occasional hair dyeing after developing gray hair generally does not lead to cancer. However, frequent hair dyeing increases the risk of cancer development. Therefore, individuals who frequently dye their hair should pay more attention to this matter. The reason why long-term hair dyeing increases the risk of cancer is primarily due to the multiple chemical substances present in hair dyes, including carcinogenic benzene, which can elevate the risk of hematological malignancies. Additionally, hair dyes often contain heavy metals such as mercury and lead, which are toxic to the liver and kidneys and may increase the risk of developing skin cancer, liver cancer, gastric cancer, and other cancers. The ingredients in hair dyes are complex, and some people may experience allergic reactions due to their sensitive constitution. Frequent allergic reactions may also induce cancer development. Therefore, it is not recommended to dye hair frequently after developing gray hair. As one ages, developing gray hair is a normal physiological phenomenon that generally does not require special treatment.