title: Trace element concentrations from lichen transplants in Pretoria, South Africa.
abstract: OBJECTIVE
  The purpose of this study was to assess the level and possible sources of trace elements in Tshwane metropolis using transplanted lichen thallus of Parmelia sulcata with a view to evaluating the ability of this lichen species to monitor air pollutants from a perceived polluted environment.
  
  
  METHODS
  Samples of the lichen thalli were transplanted into ten different sites and covered with a net. Samples were exposed for 3 months. Concentrations of ten trace elements were determined with the use of inductively coupled plasma mass spectrometry.
  
  
  RESULTS
  A significant difference was observed in the values of elemental concentration in lichen from unpolluted area and those transplanted to all the sites (p < 0.01). Variations in values of trace elements recorded in lichen transplant from different sites were also statistically significant (p < 0.01). The high traffic sites showed significantly higher elemental concentrations, particularly for Pb, Zn, and Cu than the industrial and residential areas (p < 0.05).
  
  
  CONCLUSIONS
  Trends in the trace element values from different sites suggested that the elements might have come from anthropogenic sources.
authors.affiliation: Department of Biology, University of Limpopo (Medunsa Campus), P.O.Box 139, Medunsa, Pretoria, South Africa, 0204. woleolowoyo@yahoo.com
authors.forename: Joshua Oluwole
authors.initials: JO
authors.lastname: Olowoyo
authors.forename: E
authors.initials: E
authors.lastname: van Heerden
authors.forename: J L
authors.initials: JL
authors.lastname: Fischer
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D001203:Ascomycota / Q000737:chemistry*; D004784:Environmental Monitoring / Q000379:methods*; D058865:Introduced Species; D008011:Lichens / Q000737:chemistry*; D019216:Metals, Heavy / Q000032:analysis; D013019:South Africa; D014131:Trace Elements / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D019216:Metals, Heavy; D014131:Trace Elements