  Superconducting qubits can be sensitive to abrupt energy deposits caused by
cosmic rays and ambient radioactivity. Previous studies have focused on
understanding possible correlated effects over time and distance due to cosmic
rays. In this study, for the first time, we directly compare the response of a
transmon qubit measured initially at the Fermilab SQMS above-ground facilities
and then at the deep underground Gran Sasso Laboratory (INFN-LNGS, Italy). We
observe same average qubit lifetime T$_1$ of roughly 80 microseconds at above
and underground facilities. We then apply a fast decay detection protocol and
investigate the time structure, sensitivity and relative rates of triggered
events due to radiation versus intrinsic noise, comparing above and underground
performance of several high-coherence qubits. Using gamma sources of variable
activity we calibrate the response of the qubit to different levels of
radiation in an environment with minimal background radiation. Results indicate
that qubits respond to a strong gamma source and it is possible to detect
particle impacts. However, when comparing above and underground results, we do
not observe a difference in radiation induced-like events for these sapphire
and niobium-based transmon qubits. We conclude that the majority of these
events are not radiation related and to be attributed to other noise sources
which by far dominate single qubit errors in modern transmon qubits.
