Levels Pb (Lead) Content in The Thallus Lichens at Three Shade Tress in The Terminal Pinang Baris Medan, North Sumatera

This research aims to know the levels of Pb (Lead) on thalus lichens found on the three
forest shade trees road in the area of Terminal Pinang Medan, North Sumatera. Type of this
research is a descriptive exploratory survey method. Measurement of the levels of lead (Pb) using
Furnace (destruction of dried) and Atomic Absorbance Spectrophotometer (AAS) in Medical Field
Laboratory Hall. From the results of research conducted in the Terminal Area of Pinang Baris
Medan, it is known that there are 12 different types of lichens. Results of the study known types of
lichens that have levels of lead (Pb) is a type of most lichens Parmelia grabratula 49,01 mg/kg
from Acacia trees (Acacia auriculiformis) I, and the lowest levels of lead (Pb) is a Palm tree from
Buellia canescens 10,19 mg/kg III (Hyophorbe sp.).