Final answer:
Secondary barriers, such as magnetic fields and lead shielding, provide protection from high-velocity charged particles and gamma rays that contribute to radiation exposure. These barriers deflect harmful particles and absorb radiation to reduce the health risks associated with exposure. Effective shielding is crucial since we are constantly exposed to some level of background radiation.
Step-by-step explanation:
Secondary barriers provide shielding from high-velocity charged particles which can damage biological cells and contribute to radiation exposure from sources including research facilities and natural environments. A magnetic field can be utilized as such a barrier; it can deflect charged particles away from your body, thereby reducing the risk of cellular damage. This principle is akin to how the Earth's magnetic field protects us from cosmic radiation.
Moreover, secondary barriers like lead shielding are effective against gamma rays, with higher-density materials offering better protection. The effectiveness depends on the thickness of the shielding. In medical settings, as shown in figure 32.7, shielding ensures both the patient and medical technician are protected when an x-ray is taken. Shielding also includes strategies such as increasing the distance from the radiation source and limiting exposure time to minimize health risks.
It is important to acknowledge that while we cannot eliminate exposure to ionizing radiation completely due to various natural and artificial sources, we can significantly reduce exposure by implementing effective shielding techniques and by adhering to safety protocols designed to protect us from excessive radiation.