What health effect can exposure to high levels of ionizing radiation cause?

Exposure to high levels of ionizing radiation is known to damage living tissue, which can lead to a variety of health issues. One of the most significant long-term health effects of such exposure is the development of cancers. Ionizing radiation has sufficient energy to remove tightly bound electrons from atoms, creating ions. This process can result in direct DNA damage or cause mutations in the cells, which may lead to uncontrolled cell growth and the formation of tumors.

The risk of cancer increases with the intensity and duration of radiation exposure, as well as the type of radiation. Studies have shown that individuals who are exposed to high levels of ionizing radiation, such as those working in nuclear facilities or survivors of atomic bombings, have a higher incidence of various types of cancer, including leukemia and solid tumors.

In contrast, the other choices presented are not associated with exposure to high levels of ionizing radiation. Improvements in immune response, cognitive functions, or physical strength are not documented effects of radiation exposure and would be misleading in terms of understanding the risks associated with ionizing radiation. The focus on cancer development captures the serious and well-established risks posed by such exposure, making it the correct choice.