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

In the present study, the depositions of Po-210 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 Po-210 in mosses and surface soil collected around coal-fired power plant in relation to trace the potential source of Po-210 and to identify most suitable moss species as a bio-indicator for Po-210 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 Po-210 activity concentrations in mosses and soil varied in the range 102 +/- A 4 to 174 +/- A 8 Bq/kg dry wt. and 37 +/- A 2 to 184 +/- A 8 Bq/kg dry wt., respectively. Corresponding highest activity concentration of Po-210 observed in L. aduncum, therefore, this finding can be concluded this species was the most suitable as a bio-indicator for Po-210 deposition. On the other hand, it is clear the accumulation of Po-210 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 Po-210 in surface soil is supplied from the in situ deposition of radon decay and its daughters in the soil itself.