The present disclosure provides a system for detection and measuring of a radioactive gas within a target environment. In certain embodiments, the system comprises a data processing system and a monitoring device disposed within the target environment. In some forms the monitoring device comprises: a radiation sensor configured to detect the concentration of a radioactive gas in the target environment, a transmitter electrically coupled to the radiation sensor and configured for transmitting a signal to the data processing system, and a receiver for receiving signals from the data processing system, wherein the monitoring device is configured to detect the concentration of the radioactive gas at least every twenty minutes.