What is a significant long-term effect of cumulative radiation exposure?

Cumulative radiation exposure is primarily associated with an increased risk of developing cancer and genetic defects over time. This connection arises because ionizing radiation can cause damage to the DNA within cells. As exposure accumulates, there is a higher likelihood that this DNA damage could lead to mutations. Some mutations may not present immediate effects but can disrupt normal cellular functions, potentially leading to unregulated cell growth, which is the basis of cancer development.

Additionally, genetic defects can result from radiation exposure affecting the germ cells (sperm and eggs) of an individual. If mutations occur in these cells, they can be passed on to future generations, leading to inherited conditions or defects. This dual impact of radiation on both individual health and potential genetic lineage underscores the significant long-term risks associated with cumulative exposure, making it a critical area of focus in radiation safety and health physics.

The other options mentioned are less directly related to the long-term effects of radiation exposure or are more acute in nature. Immediate fatigue, skin disease, and reduced bone density may occur due to specific exposures or health conditions but are not recognized long-term consequences of cumulative radiation exposure like cancer and genetic defects are.