Excess of polonium-210 activity in the surface urban atmosphere. Part 2: origin of 210Po excess

Abstract

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.