LEAD CONTAMINATION LEVELS IN ROADSIDE VEGETATION OF GHARIAN-TRIPOLI ROAD, LIBYA

This study was designed to determine the lead contamination in roadsides vegetation along 125 km of busy roads resulting from many sources such as the exhaust of cars that use gasoline. The area of this study was Gharian city center, and the sides of Gharian-Azizia, Azizia-Swani, Swani-Airport and Airport-Tripoli Roads. Samples were collected from the leaves of plants adjacent to public roads within the study area by distance of 2-5 km between samples within urban centers and 10-15 km within the roads, so as to give a true representation of the study area. Results of this study showed that the traffic volume caused a significant increase in Pb content in roadside vegetation. Higher Pb concentrations were found in sites with a higher traffic volume on main roads. Results showed that the rate of lead contamination varied within the study area, but generally less than 50.99 µg/100cm2. It was found that the highest percentage of pollution within the city center of Azizia with 50.99 µg/100cm2, followed by Gawasem center with 43.65 µg/100cm2 while the lowest polluted area was Azizia-Swani road with 11.58 µg/100cm2. The presence of elevated levels of lead on/in the plants closer to the roads with high traffic density caused by the use of alkyl lead compounds as antiknock and freezing additives in fuel needs more attention and some necessary steps should be adopted.