What is a common risk associated with excess exposure to ionizing radiation?

Excess exposure to ionizing radiation is well-documented to increase the risk of cancer. This is because ionizing radiation has enough energy to remove tightly bound electrons from atoms, which can lead to DNA damage in cells. When DNA is damaged, it can result in mutations that may go on to develop into cancerous cells. The relationship between ionizing radiation and cancer risk is supported by numerous studies and is a fundamental concept in radiation safety and protection.

The other options do not align with the effects of ionizing radiation exposure. Enhanced bone density and improved immune response are not associated with radiation exposure; in fact, radiation can have detrimental effects on bone health and immune function. Decreased blood pressure is also unrelated, as ionizing radiation typically does not have a direct impact on blood pressure. Therefore, the increased risk of cancer is the most relevant and supported consequence of excessive ionizing radiation exposure.