Heavy metal accumulation in some natural and exotic plants in Samsun city

Abstract

The aim of this study was to estimate the level of some trace metal accumulation (Pb, Cd, Zn and Cu) in the leaves, needles, and twigs of some natural and exotic tree and shrub species which were selected and tested as a biomonitors of these heavy metals grown in the centre and suburbs (Atakum) of Samsun, Turkey polluted by burning fossil fuels and heavy traffic conditions from December 2007 to August 2008. Air pollution from traffic density was very important for Samsun in both the winter and summer periods. Because of this reason leaf and twig samples of these species were collected in winter and summer separately. Statistically significant differences were found among the studied species regarding studied heavy metals. The highest heavy metal concentrations were found in M. grandiflora, although heavy metal concentrations may be different according to the studied species, sampling points and sampling periods. According to the obtained data it was found that M. grandiflora, Ligustrum vulgare and Phoenix dactylifera can be used as biomonitors (i.e. the highest Cu concentrations were found in Samsun city in P. dactylifera leaves (45.10) and M. grandiflora leaves (62.00) and the highest Zn concentration was found in L. vulgare leaves (69.58) during the summer. Because these species accumulated higher concentrations of heavy metals in their tissues as compared to other species. Finally, it was found that different parts of evergreen plants (i.e. leaves and twigs) can be used as biomonitors in determining heavy metal pollution.