Accumulation of Naturally-Occurring Radionuclide Polonium-210 By Phytoplankton in Urban Sea Bays

Polonium-210 (²¹⁰Po) is most available naturally occurring isotope of the polonium radionuclide with the half-life time of about 138 days. It forms in the result of ²³⁸U-²²⁶Ra decay series is 100% alpha-radioactive. These make ²¹⁰Po convenient for research purposes. Polonium is an extremely toxic element. Because of its self-heating and subsequent transformation into aerosol forms, it is dangerous even at distances far exceeding the range of alpha-particles. Therefore, understanding of ²¹⁰Po distributions in populated areas is an important environmental topic.

Polonium finds its path into sea basins from the atmosphere and various water systems. In the marine environment it connects with the organic matters and eventually enters into seafood chains. First organisms accumulating polonium relate to phytoplankton.

The present paper reports ²¹⁰Po distributions have been studied in the Sebastopol bay of the Black sea. The water samples were collected using phytoplankton nets from surface levels of water in the bay. The collection was conducted at three fixed stations and on board of a research vessel at different locations.

The obtained water samples were filtered through the nitro cellular membranes “Sartorius” with the pore diameter 1.2 um. The membranes were dried and the mass of phytoplankton was measured. Polonium was extracted from phytoplankton radiochemical means. Then polonium was deposited on disks made of silver foils. ²¹⁰Po concentrations were measured using an alpha-spectrometer.