Biomonitoring of airborne heavy metals using Brachychiton populneus (Schott & Endl.) leaves


  • Halmat A. Sabr Department of Forestry, College of Agricultural Engineering Sciences, Salahaddin University-Erbil, Kurdistan Region, Iraq



Airborne heavy metals, Brachychiton populneus, Chlorophyll content, Heavy metal accumulation, Leaves, Stomata density


Trees growing close to emission sources have higher metal concentrations in their leaves, which is an indication of how polluted these location are. Additionally, the accumulation of heavy metals such as Fe, Zn, Cu, Cd, and Pb in various tree species has increased as a result of industrial and mining operations. The aim of the present study was to use Brachychiton populneus (Schott & Endl.) tree leaves as biomonitor to evaluate air pollution of Erbil city. Samples were collected from 6 different locations. Chlorophyll content, stomata number and heavy metals in leaves were determined. The result of the present study indicated that the highest mean of chlorophyll content was recorded for control (42.76), while there was not significant effect of pollution from traffic density was recorded for location 5. Non significant effect of roadsides of stomata density was observed in leaves. Surprisingly locations 2 showed that the leaves accumulated the lowest concentration of heavy metals as compare to control location. In addition, long side roads and parks, and the study species can has the capacity to accumulate the atmospheric pollution. As an alternative to other an expensive approaches thus may play an essential part in monitoring pollution of Erbil city. Finally the measurement characteristics may be employed as a bioindicator. It is also recommended to apply air pollution tolerance index (APTI) to determine suitability for selection of tree species as biomonitor and green belt plantations.


BABA, S. A. & MALIK, S. A. 2014. Evaluation of antioxidant and antibacterial activity of methanolic extracts of Gentiana kurroo royle. Saudi J Biol Sci, 21, 493-8

ABU-ELSAOUD, A. M., NAFADY, N. A., & ABDEL-AZEEM, A. M. (2017). Arbuscular mycorrhizal strategy for zinc mycoremediation and diminished translocation to shoots and grains in wheat. PLoS One, 12(11), e0188220.‏

ADRIANO, D.C., 2001. Trace Elements in the Terrestrial Environment. Biogeochemistry, Bioavailability and Risks of Metals, second ed. Springer, New York.

AHMED, I. T., & SABR, H. A. (2020). Response of Plane Tree (Platanus orientalis L.) toward Environmental Pollution of Erbil City. Zanco Journal of Pure and Applied Sciences, 32(6), 150-157.‏

AL-KARAKI, G.N., 2013. The role of mycorrhiza in the reclamation of degraded lands in arid environments. Developments in soil classification, land use planning and policy implications: Innovative thinking of soil inventory for land use planning and management of land resources, pp.823-836.

AL-OBAIDY, A. H. M., MAHMOD, M. A., & AL-MASHHADY, A. A. (2016). Efficiency of E. microtheica and E. camaldulensis Tree to Remove Lead Element (Pb) from the Province of Baghdad Environment. Engineering and Technology Journal, 34(3 Part (B) Scientific).‏

ALVES, E.S., MOURA, B.B., DOMINGOS, M., 2008a. Structural analysis of Tillandsia usneoides L. exposed to air pollutants in Sa˜o Paulo city-Brazil. Water Air Soil Pollution 189, 61–68.

Alves, E.S., Tresmondi, F., Longui, E.L., 2008b. Leaf anatomy of Eugenia uniflora L. (Myrtaceae) in urban and rural environments, Sao Paulo State, Brazil. Acta Botanica Brasilica 22, 241–248.

BACIC, T. AND LEDIC, A., 1992. Changes of pigments content in needles of Pinus halepensis Mill. Acta Biologica Cracoviensia. Series Botanica, (34-35).

BALASOORIYA, B.L.W.K., SAMSON, R., MBIKWA, F., VITHARANA, W.A.U., BOECKX, P., VAN MEIRVENNE, M., 2009. Biomonitoring of urban habitat quality by anatomical and chemical leaf characteristics. Environmental and Experimental Botany 65, 386–394.

BAYCU, G., TOLUNAY, D., ÖZDEN, H. AND GÜNEBAKAN, S., 2006. Ecophysiological and seasonal variations in Cd, Pb, Zn, and Ni concentrations in the leaves of urban deciduous trees in Istanbul. Environmental pollution, 143(3), pp.545-554.

BETTARINI, I., VACCARI, P., MIGLIETTA, F., 1998. Elevated CO2 concentrations and stomatal density: observations from 17 plant species growing in a CO2 spring in central Italy. Global Change Biology 4, 17–22.

BIRHANE, E., STERCK, F.J., FETENE, M., BONGERS, F. AND KUYPER, T.W., 2012. Arbuscular mycorrhizal fungi enhance photosynthesis, water use efficiency, and growth of frankincense seedlings under pulsed water availability conditions. Oecologia, 169, pp.895-904.

BOZDOGAN SERT, E., TURKMEN, M., & CETIN, M. (2019). Heavy metal accumulation in rosemary leaves and stems exposed to traffic-related pollution near Adana-İskenderun Highway (Hatay, Turkey). Environmental monitoring and assessment, 191, 1-12.

BRIGHIGNA, L., RAVANELLI, M., MINELLI, A., ERCOLI, L., 1997. The use of an epiphyte (Tillandsia caput-medusae Morren) as bioindicator of air pollution in Costa Rica. The Science of the Total Environment 198, 175–180.

CAMARGO, M.A.B. AND MARENCO, R.A., 2011. Density, size and distribution of stomata in 35 rainforest tree species in Central Amazonia. Acta Amazonica, 41, pp.205-212.

CHETTRI, M.K., COOK, C.M., VARDAKA, E., SAWIDIS, T., LANARAS, T., 1998. The effect of Cu, Zn and Pb on the chlorophyll content of the lichens Cladonia convoluta and Cladonia rangiformis. Environmental and Experimental Botany 39 (1), 1e10.

DICKINSON, N.M., PULFORD, I.D., 2005. Cadmiumphytoextraction using short-rotation coppice Salix: the evidence trail. Environment International 31, 609e613.

DINEVA, S.B. 2004. Comparative studies of the leaf morphology and structure of white ash Fraxinus americana L. and London plane tree Platanus acerifolia Willd growing in polluted area. Dendrobiology journal, 52, pp.3-8.

ELAGOZ, V., HAN, S.S., MANNING, W.J., 2006. Acquired changes in stomatal characteristics in response to ozone during plant growth and leaf development of bush beans (Phaseolus vulgaris L.) indicate phenotypic plasticity. Environmental Pollution 140, 395–405.

FALLA, J., LAVAL-GILLY, P., HENRYON, M., MORLOT, D., FERARD, J.F., 2000. Biological air quality monitoring: a review. Environmental Monitoring and Assessment 64, 627–644.

GIRI, S., SHRIVASTAVA, D., DESHMUKH, K. AND DUBEY, P., 2013. Effect of air pollution on chlorophyll content of leaves. Current Agriculture Research Journal, 1(2), pp.93-98.

GU, Y.G. AND GAO, Y.P., 2018. Bioaccessibilities and health implications of heavy metals in exposed-lawn soils from 28 urban parks in the megacity Guangzhou inferred from an in vitro physiologically-based extraction test. Ecotoxicology and Environmental Safety, 148, pp.747-753.

GUYMER, G.P. (1988). A taxonomic revision of Brachychiton (Sterculiaceae). Aust. Syst. Bot., 1(3): 199-323.

HILDEBRANDT, U., REGVAR, M., & BOTHE, H. (2007). Arbuscular mycorrhiza and heavy metal tolerance. Phytochemistry, 68(1), 139-146.‏

JOSHI, P.C. AND SWAMI, A., 2009. Air pollution induced changes in the photosynthetic pigments of selected plant species. Journal of Environmental Biology, 30(2), pp.295-298.

KABATA-PENDIAS, A., 2000. Trace elements in soils and plants. CRC press.

KABATA-PENDIAS, A., PENDIAS, H., 1986. Trace Elements in Soils and Plants. CRC Press Inc., Boca Raton, Florida.

KAMBEZIDIS, H. D., SAKELLARIOU, N. K., TOPALIS, F. B., KANELLIAS, A. A., & PETROVA, V. D. 1996. Air pollution monitoring with a passive pyrheliometric scanner. Fresenius Environmental Bulletin, 5(11), 631-636.‏

KARDEL, F., WUYTS, K., BABANEZHAD, M., WUYTACK, T., POTTERS, G., & SAMSON, R. 2010. Assessing urban habitat quality based on specific leaf area and stomatal characteristics of Plantago lanceolata L. Environmental Pollution, 158(3), 788-794.‏

KARMAKAR, D., DEB, K. AND PADHY, P.K., 2021. Ecophysiological responses of tree species due to air pollution for biomonitoring of environmental health in urban area. Urban Climate, 35, p.100741.

KOLLIST, H., NUHKAT, M. AND ROELFSEMA, M.R.G., 2014. Closing gaps: linking elements that control stomatal movement. New Phytologist, 203(1), pp.44-62.

LARCHER, W., 2003. Physiological Plant Ecology: Ecophysiology and Stress Physiology of Functional Groups, fourth ed. Springer, p. 437–450.

MARKERT, B., 1993. Plants as biomonitors.

MENDOZA-TAFOLLA, R.O., JUAREZ-LOPEZ, P., ONTIVEROS-CAPURATA, R.E., SANDOVAL-VILLA, M., IRAN, A.T. AND ALEJO-SANTIAGO, G., 2019. Estimating nitrogen and chlorophyll status of romaine lettuce using SPAD and at LEAF readings. Notulae Botanicae Horti Agrobotanici Cluj-Napoca, 47(3), pp.751-756.

NAGAJYOTI, P. C., LEE, K. D., & SREEKANTH, T. V. M. 2010. Heavy metals, occurrence and toxicity for plants: a review. Environmental chemistry letters, 8, 199-216.‏

OMAKA, N.O., OFFOR, I.F. AND EHIRI, R.C., 2014. Fe, Pb, Mn, and Cd Concentrations in Edible Mushrooms (Agaricus campestris) Grown in Abakaliki, Ebonyi State, Nigeria. International Journal of Agricultural and Biosystems Engineering, 8(1), pp.84-88.

PAOLETTI, E., & GRULKE, N. E. 2005. Does living in elevated CO2 ameliorate tree response to ozone? A review on stomatal responses. Environmental Pollution, 137(3), 483-493.‏

PICZAK, K., LES´NIEWICZ, A., Z´ YRNICKI, W., 2003. Metal concentrations in deciduous tree leaves from urban areas in Poland. Environmental Monitoring and Assessment 86, 273e287.

POURKHABBAZ, A., RASTIN, N., OLBRICH, A., LANGENFELD-HEYSER, R. AND POLLE, A., 2010. Influence of environmental pollution on leaf properties of urban plane trees, Platanus orientalis L. Bulletin of environmental contamination and toxicology, 85(3), pp.251-255.

PULFORD, I.D. AND DICKINSON, N.M., 2005. 90 Phytoremediation Technologies Using Trees. Trace elements in the environment: biogeochemistry, biotechnology, and bioremediation, p.383.

RAI, P.K., 2016. Impacts of particulate matter pollution on plants: Implications for environmental biomonitoring. Ecotoxicology and environmental safety, 129, pp.120-136.

RATE, A.W., 2018. Multielement geochemistry identifies the spatial pattern of soil and sediment contamination in an urban parkland, Western Australia. Science of the Total Environment, 627, pp.1106-1120.

SANDELIUS, A.S., NÄSLUND, K., CARLSSON, A.S., PLEIJEL, H. AND SELLDÉN, G.U.N., 1995. Exposure of spring wheat (Triticum aestivum) to ozone in open‐top chambers. Effects on acyl lipid composition and chlorophyll content of flag leaves. New Phytologist, 131(2), pp.231-239.

SAWIDIS, T., CHETTRI, M.K., PAPAIOANNOU, A., ZACHARIADIS, A., STRATIS, J., 2001. A study of metal distribution from lignite fuels using tree as biological monitors. Ecotoxicology and Environmental Safety 48, 27e35.

SINGH, S.N. AND VERMA, A., 2007. Phytoremediation of air pollutants: a review. Environmental bioremediation technologies, pp.293-314.

SITKO, R., ZAWISZA, B., JURCZYK, J., BUHL, F. & ZIELONKA, U. 2004. Determination of High Zn and Pb Concentrationsin Polluted Soils Using Energy-Dispersive X-rayFluorescence Spectrometry. Journal of Environmental Studies and Sciences. 13(1): 91-96.

TANG, J., ZHANG, J., REN, L., ZHOU, Y., GAO, J., LUO, L., YANG, Y., PENG, Q., HUANG, H. AND CHEN, A., 2019. Diagnosis of soil contamination using microbiological indices: A review on heavy metal pollution. Journal of Environmental Management, 242, pp.121-130.

TRIPATHI, A.K. AND GAUTAM, M., 2007. Biochemical parameters of plants as indicators of air pollution. Journal of environmental biology, 28(1), p.127.

UNTERBRUNNER, R., PUSCHENREITER, M., SOMMER, P., WIESHAMMER, G., TLUSTOŠ, P., ZUPAN, M., & WENZEL, W. W. (2007). Heavy metal accumulation in trees growing on contaminated sites in Central Europe. Environmental pollution, 148(1), 107-114.‏

VISKARI, E. L., & KÄRENLAMPI, L. (2000). Roadside Scots pine as an indicator of deicing salt use–a comparative study from two consecutive winters. Water, Air, and Soil Pollution, 122, 405-419.

VOLENÍKOVÁ, M.; TICHÁ, I. 2001. Insertion profiles in stomatal density and sizes in Nicotiana tabacum L. plantlets. Biologia Plantarum, 44: 16116.

YABANLI, M., YOZUKMAZ, A. AND SEL, F., 2014. Heavy metal accumulation in the leaves, stem and root of the invasive submerged macrophyte Myriophyllum spicatum L.(Haloragaceae): an example of Kadin Creek (Mugla, Turkey). Brazilian Archives of Biology and Technology, 57, pp.434-440.



How to Cite

Sabr, H. A. (2023). Biomonitoring of airborne heavy metals using Brachychiton populneus (Schott & Endl.) leaves. Zanco Journal of Pure and Applied Sciences, 35(6), 179–188.



Agricultural and Environmental Researches