The date palm ( Phoenix dactylifera L.) as a biomonitor of lead and other elements in arid environments

The date palm ( Phoenix dactylifera L.) has been tested as a possible biomonitor of metal pollution in Riyadh city, Saudi Arabia. The metal content (Pb, Zn, Cu, Ni, Cr and Li) was determined for washed and unwashed leaflets collected from a wide range of sites with different degrees of metal pollution (urban, suburban, highway and industrial areas) and from a rural (control) site. Differences between washed and unwashed samples revealed that metal pollutants exist as superficial contaminants, especially levels of Pb and Zn, which varied according to the metal source. However, P. dactylifera leaflets were found to be suitable biomonitors for metal pollution in Riyadh and similar arid and semi-arid environments.