The response of E. coli Bs-1 to tritium-beta particles under aerated and anoxic conditions

E. coli Bs-1 cells were exposed to acute doses of tritium-beta particles by suspension in tritiated water for known lengths of time. The resulting survival rate was compared with that obtained for external irradiation with 7 MeV electrons. The o.e.r. measured for tritium-beta s was not significantly different from the value of 2.15 measured for 7 MeV electrons. The r.b.e. of the tritium beta s relative to 7 MeV electrons was 1.21 in both air and nitrogen. These results were compared with existing data for low voltage electron irradiations and with track segment studies of the effect of varying LET on the radiosensitivity of E. coli Bs-1.