Background radiation, radiation dose or gamma radiation background are terms used when speaking of ionizing radiation. The process by which an object is exposed to radiation is called irradiation.
The radiation penetrates all sorts of human tissue, ionizes the cells and molecules, leading to formation of ionized atoms (ions or free radicals) which destroy the organism’s molecules and lead to mass cell death.
To assess the impact of radiation on the human body, the term “equivalent dose” is used which is a dose quantity H representing the stochastic health effects of low levels of ionizing radiation on the human body which represents the probability of radiation-induced cancer and genetic damage. In the SI system of units, the unit of measure is the sievert (Sv).
The permissible doses of ionizing radiation in Bulgaria are determined by the Regulation on basic norms of radiation protection. It determines the permissible radiation doses, excluding the doses from natural background radiation. The natural background radiation levels in Bulgaria vary between 0.06 and 0.40 µSv\h. The limit of effective dose of ionizing radiation for every person of the population in Bulgaria is 1 mSv for 1 year or 0.1 μSv.h−1 (calculated for 8800 hours).
In case of contamination with radioactive substances, measures are taken depending on the annual effective dose above the natural background radiation as the levels are determined in the respective legislative regulations.
In order to have real-time data and monitor the possible risk to the population, Gabrovo Municipality implemented a complete solution for background radiation monitoring in real time. The solution consists of a high-class device Senstate Environmental Radiation Monitor, which transmits information in real time to a cloud-based system for data management. The collected information is used for conducting analyses and visualization, as the system offers the options to create “events” and receive alarms, to identify dependencies, and to track the compliance with the regulations of permissible levels of radiation in the environment. All of the data are made accessible to the citizens of the town on the following website: https://green.gabrovo.bg/ .