background radiation

level of ionizing radiation present in the natural environment

en-GB/ˈbækɡɹaʊnd ˌɹeɪdɪˈeɪʃən/
en-US/ˈbækˌɡɹaʊnd ˌɹeɪdiˈeɪʃən/

زمرے:

ionizing radiation