æz ʌv tˈuː θˈaʊzənd fˈaɪv, sˈiːsiəm wˈʌnhˈʌndɹɪd θˈɜːɾi sˈɛvən ɪz ðə pɹˈɪnsɪpəl sˈoːɹs ʌv ɹˌeɪdɪˈeɪʃən ɪnðə zˈoʊn ʌv ˌeɪliənˈeɪʃən ɚɹˈaʊnd ðə tʃˈɜːnəbˌɪl nˈuːklɪɹ pˈaʊɚ plˈænt.
As of 2005, caesium-137 is the principal source of radiation in the zone of alienation around the Chernobyl nuclear power plant.