Determination of Elements due to Atmospheric Deposition on Barbula indica Moss at Dalat, Vietnam using NAA and TXRF Techniques

In this paper, two multielement analysis techniques, Neutron Activation Analysis (NAA) and Total Reflection X-ray Fluorescence (TXRF), are combined to detect elemental concentrations in Barbula indica moss collected at Dalat, Vietnam. Combining these two techniques has improved the qualitative detection of elements due to atmospheric deposition on moss samples. The concentrations of 40 elements, including Na, Mg, Al, Si, P, S, Cl, K, Ar, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Kr, Rb, Y, Sb, I, Cs, Ba, La, Ce, Sm, Eu, Tb, Dy, Yb, Hf, Ta, Pb, Th, and U in the Barbula indica moss samples collected at 19 locations at Dalat have been determined. It is shown that the air in Dalat is suspected of contamination by Na, Mg, Si, P, S, V, Mn, Cu, Se, Br, and U; slightly contaminated by Mg, Cl, K, Cr, Ni, S, and Ni; moderately contaminated by Sc, Fe, Co, Zn, As, Kr, Rb, Y, Sb, Cs, Ba, La, Ce, Sm, Eu, Dy, Yb, Ta, Pb, and Th; and seriously contaminated by Tb. Factor analysis has been used to explain the contamination sources of these elements, including V, As, Fe, Zn, Se, Rb, Sb, Cs, Al, Cu, and Pb in the investigated area. Four factors have been extracted that can explain 86% of the total variance, and the results suggest that the main sources of atmospheric pollution in Dalat originate from traffic and windblown dust.