Which method of reducing radiation exposure is most effective for a radiography technician at a job site?

Using shielding materials is the most effective method for reducing radiation exposure for a radiography technician at a job site. Shielding involves placing a material between the radiation source and the individual to absorb or deflect the radiation, thereby minimizing the amount that reaches the technician. Common shielding materials include lead, concrete, and other dense substances that effectively attenuate radiation.

This approach is based on the principle that radiation intensity decreases with increased shielding, which is crucial in environments where technicians are frequently exposed to ionizing radiation. By employing shielding, technicians can work safely in proximity to radiation sources without significantly increasing their dose.

For context, the other methods mentioned do not effectively reduce exposure. Increasing time spent near the source naturally increases radiation dose, posing a risk to the technician's health. Decreasing distance from the source also raises exposure, as radiation intensity is inversely proportional to the square of the distance from the source—closer proximity results in higher dose rates. Lastly, avoiding personal protective equipment contradicts safety practices and does not contribute to reducing exposure; rather, it increases vulnerability to radiation. Therefore, the use of shielding materials is the most effective strategy for ensuring the safety of radiography technicians.