摘要：This study reports on the accumulation of lead (Pb) in the talus Lichenes found on roadside stands of mahogany trees in the city of Medan, North Sumatra, Indonesia. Samples were taken by purposive, ie location based on the level of traffic density with different air pollution. Pb analysis was performed using Atomic Absorption Spectroscopy (AAS). Identified as many as 8 kinds of Lichens with 2 types, namely talus Crustose and foliose. Type of Lepraria incana and Pertusaria amara , which is found in the three study sites belonging to the cosmopolitan types. Pb accumulated in the talus Pertusaria amara ranged from 5.23 to 15.07 ppm. Being on Lepraria incana ranged 1.19 to 4.88 ppm. Pertusaria amara much larger than the Lepralia incana , have potential as bio-indicators of resistance. Lichen es Pb correlation with traffic density showed Pertusaria amara has a very high level and significant correlation compared with other types.
