Due to increasing heavy metal pollution in the environment as well as to the fact that pine needles are considered as good bio-monitors for air pollutants, their accumulation in pine needles in Vienna (Austria) was investigated. P. nigra J. F. Arnold, also called Austrian pine, is widespread in the city, thus allowing the study of different parameters influencing metal accumulation. The sampling sites were chosen based on traffic volume (low, medium, high). Fresh needles were collected alongside one-year-old needles once per week from May to August 2015, to test for changes in space and time.
Washed and dried samples underwent acidic microwave assisted digestion prior to quantitative determination by spectrometric methods. The investigation was focused on 22 elements, namely Ag, Al, As, B, Ba, Be, Cd, Co, Cr, Cu, Fe, K, Li, Mn, Mo, Ni, Pb, Se, Sr, U, V, and Zn.
Older needles mainly contained higher contents of elements, especially of Ag, B, Ba, Co, Cr, Fe, K, Li, Pb, Se, Sr, U, and V, whose values even differed statistically significantly.
Correlating needle elemental contents with sampling site, i.e. traffic volume, only negligible influence by this parameter was found. These findings show that not only the local traffic situation determines the metal impact, but also soil elemental levels and translocation processes and/or not traffic related sources even in remote places have to be taken into account. Furthermore, no general trend of metal accumulation from spring to summer was registered.
2019.