Excess of polonium-210 activity in the surface urban atmosphere. Part 2: origin of 210Po excess
The presence of significant 210Po activity, unsupported by its grandparent radionuclide 210Pb, in the surface atmosphere of industrialized regions can originate from human technical activities. In urban air, the activity ratio of 210Po to 210Pb might increase as a result of natural condensation and coagulation processes of relatively volatile 210Po-containing species emitted during coal combustion processes. The presence of excess of 210Po cannot be explained by its in-growth from radioactive decay of 210Bi. About 50% of 210Po radionuclide released during coal combustion processes can be emitted into air as gaseous or ultrafine products. Subsequently, these products are quickly attached to the surface of fine particles suspended in the air. As a result, an excess of 210Po activity in aerosols has been reported. However, in this manner, As much as 11 GBq of 210Po per year can enter the urban air from the local coal power plants in Lodz city, Poland.