What factors can cause variation in radiation exposure in different regions?

The correct response encompasses a variety of factors that contribute to the variation in radiation exposure across different regions.

Altitude plays a significant role because as elevation increases, the atmosphere becomes thinner and less effective at shielding cosmic radiation. Therefore, individuals located at higher altitudes may experience higher levels of radiation exposure from cosmic rays compared to those at sea level.

Background radiation, which is the ionizing radiation present in the environment, also varies geographically. This includes radiation from natural sources like radon gas, uranium in the soil, and cosmic sources. Areas with higher concentrations of these natural radioactive materials will have an elevated background radiation level.

Combining these elements, it is clear that variations in radiation exposure can be attributed to a multitude of factors including altitude and background radiation. Recognizing the interplay between these elements highlights the complexity of assessing radiation risk in different environments, making it evident why each factor is important in this context.