Fixation and localisation of manganese in some soft water organisms: I - Distribution of ⁵⁴Mn in an ecologic system in fresh water; II - study by biochemical fractionation of manganese contained by isolated plant cells

After having recalled that Manganese 54, an irradiation product of ⁵⁴Fe, has a sufficiently long radioactive period to be detected in atmospheric fallouts of nuclear explosions, but also in radioactive wastes produced by research centres, and is generally produced by corrosion of any enclosure submitted to neutron irradiation, the authors report the experimental study of a radioactive pollution of fresh water when this radio-element is a component of this pollution. Different containers are considered. They contain either water and sediments, or water and organic compounds and aquatic plants, or water and sediments and aquatic plants. A solution of ⁵⁴MnCl₂ of radioactive pollution is introduced in these containers and the authors study the decrease of radioactivity in water with respect to the considered ecosystem, the ⁵⁴Mn concentration in aquatic living species, and the distribution of ⁵⁴Mn after 43 days. In a second part, they report the study of the distribution of cellular manganese in isolated biochemical fractions by using the Schmidt and Thannhauser method. Due to the low content, the detection of this mineral nutrient requires a highly sensitive method: dosing of natural manganese by radio-activation