Which of the following practices helps shield against radiation?

Using walls or barriers made of dense materials is a fundamental practice for shielding against radiation. Dense materials, such as lead, concrete, and steel, are effective because they can absorb or scatter radiation, significantly reducing the amount that penetrates through to adjacent areas. This is crucial in environments where radiation is present, such as medical facilities, research laboratories, or nuclear power plants.

Dense materials work by providing a physical barrier that interacts with the radiation particles or photons, thereby diminishing their intensity. For instance, lead is commonly used for shielding X-rays and gamma rays due to its high density and atomic number, which makes it effective at absorbing high-energy photons. Additionally, appropriate thickness and types of materials can be selected based on the type of radiation present and the level of exposure.

In contrast, wearing only lab coats does not provide adequate shielding against radiation, as standard lab coats are typically not made from materials that can effectively block radiation. Standing next to the radiation source is certainly not a protective measure and would increase exposure. Incremental monitoring of exposure is an important safety practice to track radiation levels, but it does not actually shield against the radiation itself. Thus, the effective practice for shielding against radiation is utilizing barriers made of dense materials.