Analisis Kadar Timbal (Pb) dalam Daun Angsana (Pterocarpus indicus) sebagai Tanaman Peneduh Penyerap Polutan di Tiga Jalan Protokol Kota Medan

Abstract

Medan City is the third largest city in Indonesia with the population increasing from 2,464,512 people in 2022 to 2,474,166 people in 2023. Along with population growth, the number of motorized vehicles is also increasing, from 3,634,356 units in November 2024 to 3,672,898 units in February 2025, potentially increasing emissions of pollutants such as lead (Pb). This study was conducted at the Laboratory of the Palm Oil Research Center (PPKS), Medan, in May-July 2024, with a purposive sampling method on three protocol roads: Dr. Mansyur Street, Setia Budi Street, and Ring Road. A total of nine angsana leaf samples were analyzed for lead content using Atomic Absorption Spectrophotometry (AAS). The results showed that the lead levels were below the detection limit of the instrument (0.0641 ppm) and far below the threshold of the Indonesian National Standard (0.5-3.0 ppm). The low lead levels were influenced by the presence of vegetation cover and the policy of using unleaded gasoline since 2006. Continuous monitoring of lead levels in the environment is necessary to ensure the effectiveness of the policy. Further research could explore other sources of lead pollution, additional bioindicator trees, and their health impacts.