Determination of trace elements in epiphytic lichens from Bandar Baru Bangi, Selangor using INAA method

Abstract

Lichens have been used as effective biomonitors of atmospheric pollutants as they can take up nutrients and pollutants directly from the atmosphere. In this study, trace element contents in epiphytic lichens were determined using INAA method. Samples were collected from 7 sampling locations around Bandar Baru Bangi, Selangor. The elements detected were As (1.73±0.85 mg/kg), Ce (3.65±1.91 mg/kg), Co (0.29±0.12 mg/kg), Cr (5.92±3.54 mg/kg), Cs (0.92±0.25 mg/kg), Eu (0.03±0.02 mg/kg), Fe (1280±760 mg/kg), Hf (0.37±0.18 mg/kg), La (1.52±0.89 mg/kg), Rb (27.7±4.8 mg/kg), Sc (0.33±0.19 mg/kg), Sm (0.28±0.16 mg/kg), Th (1.21±0.62 mg/kg) and Zn (116±27 mg/kg). Comparisons were then made between the elemental concentrations obtained and the baseline data from literature. Results showed that most of the elements were within the concentration range of the baseline data. Enrichment factors (EF) of the trace element in lichens showed that most of the elements were within the range of the baseline data except for As which was found to be slightly enriched (EF: 13.2 - 28.5). Regression analysis indicated significant correlation (p<0.05) with Sc for most of the elements which signifies crustal input except for Cs and Rb. The poor correlations of Cs and Rb with Sc may be due to the mobility of these elements. In summary, trace element data obtained using INAA were very useful and demonstrated that lichens were suitable biomonitors for identifying potential trace element pollutants in ambient air around the sampling area. © 2014 AIP Publishing LLC.