Urban tree bark analysis for monitoring of air pollution level in Jakarta business district

Abstract

Jakarta has become one of the cities with the highest air pollution levels among emerging countries. In urban areas such as Jakarta, trees on the roadside have the potential for biomonitoring due to significant pollutants sourced from the traffic. The bark provides information about air pollution due to its furrowed surface and collects atmospheric particle matter (PM). Therefore, the structure of the bark and surface pollutants of 20 rain trees (Samanea saman (Jacq.) Merr.) in the four lots at Sudirman Central Business District (SCBD) Jakarta were assessed. The study aimed to evaluate of air condition in the SCBD area based on the analysis of the bark structure and concentrations of important pollutant elements of Pb (plumbum), Cd (cadmium), Cu (cuprum), Cr (chromium), Mn (manganese), and Zn (zinc) on the bark. The results showed the bark thickness ranges from 3-9 mm with an average of 6.13 mm. The cuticula was gray-black in color, the phloem was brownish, and the cambium layer was very thin. Cu, Cr, Mn, and Zn were detected based on the analysis of the elements. However, Cd was not found in all trees in these four lots. Furthermore, Mn is the dominant pollutant in all trees, more than 40 ppm or more than 69% of the total, followed by Cu, Zn, and Cr. Based on the result, pollutant analysis through accumulated matter on the bark have the potential to be used as biomonitoring in urban areas.