What is a key indicator that a radon monitor has been tampered with?

A key indicator that a radon monitor has been tampered with is evidence of moving the monitor. This is crucial because radon levels can vary significantly within a building based on location, airflow, and time of measurement. When a monitor is relocated, especially without proper documentation, it can lead to the collection of inaccurate data, which could misrepresent the radon levels present in a space.

When a monitor is moved, any readings taken after that point may not reflect the radon concentration in the original study area, leading to potentially erroneous conclusions about the safety or risk levels in the environment. Tampering, such as moving the monitor, undermines the integrity of the measurement process and suggests that the data might have been manipulated for some purpose.

Other indicators, such as altered start dates or deviations in temperature, may not directly imply tampering in the same way. For example, changes in air pressure can occur due to natural atmospheric conditions and might not be indicative of interference with the monitoring process. Thus, the evidence of physically moving the monitor stands out as a critical warning sign of potential tampering.