What is a Geiger-Müller counter used for?

A Geiger-Müller counter is specifically designed to detect and measure ionizing radiation levels, which includes alpha particles, beta particles, and gamma rays. This device functions by using a Geiger-Müller tube filled with gas that becomes ionized when radiation passes through it. This ionization creates a pulse of current that can be counted and translated into a measurable quantity of radiation exposure.

The other options do not align with the primary function of a Geiger-Müller counter. It does not store radioactive materials, as that would require containment solutions rather than detection. Additionally, while shielding against radiation exposure is a critical aspect of radiation safety, it is not a function of the Geiger-Müller counter itself. Lastly, monitoring air quality typically involves different instruments designed to measure particulate matter and chemical pollutants rather than radiation levels, making this function unrelated to the purpose of a Geiger-Müller counter.