Utilization of a Well-known Biomonitor Plant Robinia Pseudoacacia L. to Evaluate Heavy Metal Pollution Levels in Istanbul/Turkey
Black locust (RobiniapseudoacaciaL.)is a widely planted biomonitoring tree for ornamental, shelterbelt and land reclamation purposes. These plants, particularly on the roadsides are exposed to intensive heavy metal pollutions originating from traffic emissions and/or industrial disposals.Present work has utilized the well-known biomonitor plant R. pseudoacaciato evaluate the heavy metal pollution levels in Istanbul/Turkey. For this, plant (unwashed/washed leaves, stem and bark) and soil samples were collected from various stations of Istanbul/Turkey such as Dilovası (industrial zone), Prince Island (cleanzone/control), and Barbaros Boulevard, Bagdat Avenue and Trans-European Motorway or TEM(roadsides).Concentrations ofheavy metals and mineral nutrients such as B, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb and Zn were measured by using ICP-OES. In soil samples, following lowest/highest element values were measured in respect to their stationaries (Dilovası and Prince Islands, therein D and PI, respectively); 17.49±0.36 (D)/34.898±0.71 (PI) for B;20535.347±624.84 (PI)/30063.130±625.41 (D) for Ca;0.618±0.01(PI)/6.119±0.11(D) for Cd;8.763±0.16 (PI)/28.921±0.46(D) for Cr;20.749±0.41 (PI)/66.836±1.313 (D) for Cu;1767.070±39.48 (PI)/2139.285±40.76(D) for Fe;13375.82±207.85 (D)/20047.094±353.103(PI)for K;2721.780±72.77 (D)/4166.854±147.01(PI) for Mg;389.210±8.47 (PI)/633.313±13.18 (D) for Mn;1651.652±50.78 (D)/2449.783±71.94 (PI)for Na;19.194±0.75(PI)/42.754±1.619 (D) for Ni;24.110±0.74 (PI)/69.810±2.21(D) for Pb;and 342.640±9.098(PI)/452.105±12.177 (D) for Zn. Theconcentrations of Ca, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn in soil samples were relatively higher in Dilovası station which is an industrial zone, whereas levels of some mineral elements such asB, K and Mg were higher in Prince Islands.Besides, the following lowest/highest element values were also measured in respect to plant parts; 2.800±0.07(stem in D)/28.749±0.49 (unwashedleaf in PI) for B; 9998.307± (stem in PI)/29863.831±491.56(bark in D) for Ca; 0.157±0.003 (stem inPI)/5.246±0.10 (unwashed leaf inD) for Cd; 2.117±0.03 (stem inPI)/16.054±0.25 (bark in D) for Cr;9.974±0.12 (stem inPI)/60.631±1.32(unwashed leaf inD) for Cu; 63.565±1.19 (stem inPI)/201.835±4.48(bark inD) for Fe; 7890.791±122.62 (stem inD)/17026.936±283.13 (unwashed leaf inPI) for K; 991.260±30.12 (stem in D)/3417.441±102.12 (unwashed leaf in PI) for Mg; 24.740±0.55 (stem inPI)/146.023±3.326 (bark inD) for Mn; 87.802±2.543 (stem inD)/304.958±9.61 (unwashed leaf inPI) for Na; 2.464±0.10 (stem inPI)/27.215±1.072 (unwashed leaf inD) for Ni; 6.534±0.24(stem inPI)/77.305±2.52 (unwashed leaf inD) for Pb; and31.844±0.829 (stem inPI)/135.388±3.547 (unwashed leaf inD) for Zn.Evaluating the element concentrations in plant samples, a high difference (about 40%) was observed forthe washed and unwashed leaves of B and Mg elements from Dilovası (industrial zone), indicating that airborne particulates could bethe main source of pollution in the environment. In addition, toxic heavy metal Cd was found to be about 17-22 times more accumulated in plants from Dilovası compared to samples from Prince Island (clean zone/control).
Keywords- Urban pollution, monitoring, trace element, mineral nutrient, soil.