Assessment of 210Po deposition in moss species and soil around coal-fired power plant

In the present study, the depositions of 210Po were assessed in the surface soil and some mosses species found in the area around coal fired power plant using radiochemical deposition and alpha spectrometry counting system. The purposes of the study were to determine activity concentrations of 210Po in mosses and surface soil collected around coal-fired power plant in relation to trace the potential source of 210Po and to identify most suitable moss species as a bio-indicator for 210Po deposition. In this study, different species of mosses, Orthodontium imfractum, Campylopus serratus and Leucobryum aduncum were collected in May 2011 at the area around 15 km radius from Tanjung Bin coal-fired power plant located in Pontian, Johor. The 210Po activity concentrations in mosses and soil varied in the range 102 ± 4 to 174 ± 8 Bq/kg dry wt. and 37 ± 2 to 184 ± 8 Bq/kg dry wt., respectively. Corresponding highest activity concentration of 210Po observed in L. aduncum, therefore, this finding can be concluded this species was the most suitable as a bio-indicator for 210Po deposition. On the other hand, it is clear the accumulation of 210Po in mosses might be supplied from various sources of atmospheric deposition such as coal-fired power plant operation, industrial, plantation, agriculture and fertilizer activities, burned fuel fossil and forest; and other potential sources. Meanwhile, the main source of 210Po in surface soil is supplied from the in situ deposition of radon decay and its daughters in the soil itself.