pˈɑːɹʃəl sˌʌbstɪtˈuːʃən ɪz kwˈaɪt pˈɑːsᵻbəl ænd ɹˈæðɚ nˈɑːntˈɑːksɪk: ɐ sˈɛvənti kˌeɪdʒˈiː pˈɜːsən kəntˈeɪnz ˌɔn ˈævɹɪdʒ zˈiəɹoʊ.θˈɜːɾi sˈɪks dʒˈiː ʌv ɹuːbˈɪdiəm, ænd ɐn ˈɪŋkɹiːs ɪn ðɪs vˈæljuː baɪ fˈɪfti tə wˈʌnhˈʌndɹɪd tˈaɪmz dɪdnˌɑːt ʃˈoʊ nˈɛɡətˌɪv ɪfˈɛkts ɪn tˈɛst pˈɜːsənz.
Partial substitution is quite possible and rather non-toxic: a 70 kg person contains on average 0.36 g of rubidium, and an increase in this value by 50 to 100 times did not show negative effects in test persons.