A. Aksoy*, D. Demirezen

Transcription

1 Polish Journl of Environmentl Studies Vol. 15, No. 1 (26), Originl Reserch Frxinus excelsior s Biomonitor of Hevy Metl Pollution A. Aksoy*, D. Demirezen Erciyes University, Fculty of Arts nd Science, Deprtment of Biology, 3839 Kyseri, Turkey Received: Ferury 2, 25 Accepted: My 3, 25 Astrct Frxinus excelsior L. (Common Ash) is deciduous tree tht grows in wild nd urn Turkey. Frxinus excelsior hs een tested s possile iomonitor of hevy metls in the city of Kyseri, Turkey. Forty-eight sites (urn rod side, rod side, urn prk, industril, suurn nd rurl sites) in nd round the city of Kyseri were investigted. In this study, the concentrtions of P, Cd, Cu, Zn, Ni nd Cr in unwshed nd wshed leves nd soils were determined. There were significnt reltionships etween smples of the hevy metl concentrtions from surfce soil nd wshed leves. The concentrtions of hevy metls in the leves of F.excelsior incresed long with the urniztion of the sites. Frxinus excelsior ws found to e useful iomonitor of the determined hevy metls. Keywords: hevy metl, pollution, iomonitor, Frxinus excelsior, urn environment. Introduction One of the first ttempts for the ssessment of environmentl pollution coming from exhust gses of utomoiles in trffic y using plnts is sed on the nlyses of different trees, grsses, nd vegetles tht grow ner highwys nd cities, which ws used s common method in the erly 196s. Lter on, this prolem ecme n oject of extensive investigtion of mny reserchers [1, 5]. Minly tree leves nd rk, hers, lichen nd moss were used s ioindictor species [1]. Biologicl indictors hve een used for mny yers to detect the deposition, ccumultion nd distriution of hevy metl pollution [6]. During the pst few decdes there hs een n increse in the use of higher plnt leves s iomonitors of hevy metl pollution in the terrestril environment [3, 5, 7, 8]. Uptke nd ccumultion of elements in plnts my follow different pths, i. e. the folir surfce nd the root system. The reltive importnce of these routes for pollutnt flux towrd the leves isn t cler on tree leves [9, 11]. *Corresponding uthor; e-mil: ksoy@erciyes.edu.tr The im of this study is to determine the P, Cd, Cu, Zn, Ni nd Cr concentrtions in surfce soil nd in unwshed nd wshed leves of F. excelsior (sh) which ws selected nd tested s iomonitor of these hevy metls in Kyseri, locted in Centrl Antoli. Mterils nd Methods Frxinus excelsior L. Frxinus excelsior is deciduous tree which under most fvorle conditions my rech heights of over 4 m with girth of up to 6 m, lthough under extreme conditions it my remin shru. Frxinus excelsior is common on soils of high se sttus which prefer clcreous soils such s limestone nd chlk, where it my ecome undnt voiding the soils tht re mrkedly cidic [12]. Frxinus excelsior requires the soil to e rich in humus nd nutrients nd cn multiply in rich soil tht ccumultes in crcks of mountin limestone. Frxinus excelsior, tll tree, is redily distinguished y its light-grey rk nd y its lrge compound leves. Both rk nd the leves hve medicinl use. This plnt

2 28 is ntive to Europe, the Cucsus nd Turkey [13]. However, it s grown in grdens nd is lso populr s n urn ornmentl plnt throughout Asi nd Europe. Frxinus excelsior is clled pioneer tree, which is tolernt of the intensity of rnges of most environmentl fctors except shortge of light. Study Are Kyseri is locted in the Irn-Turn phytogeogrphicl region of Turkey. Smples were tken from Kyseri. Six different types of sites were smpled, nmely urn rodside, rod side urn prk, industril, suurn sites with the im of reflecting progressive decrese in urniztion nd thus likely pollution levels. Urn rodside sites were selected minly ner the city center long the usy min rods. Rodside sites were chosen long the Kyseri- Kırşehir highwys t 2-35 km. The trffic density of this rod ws estimted to e 285 vehicles per hour. The industril sites were chosen from the industril re tht is locted pproximtely 15 km from the city of Kyseri. The suurn sites were chosen from the edge of the city in the residentil res with reltively low humn ctivity. Rurl sites locted pproximtely 25 km wy from center were chosen. However, low level of contmintion should lso e expected even in these sites considering the frm nd visitors trffic. Smple Collection nd Preprtion Smples of plnts nd soils were collected from different sites during July 22. The numers of sites from ech ctegory smpled were s follows: rodside = 1, urn rodside = 1, urn prk = 1, Industril re = 6, suurn re = 6 nd rurl re = 6 (control). At ech site, soils were smpled from the top 1 cm y mens of stinless steel trowel to void contmintion. The soil smples were ir dried nd then pssed though 2 mm sieve. Approximtely 15 g (fresh wt) of similr sized well-developed leves of F. excelsior were selected nd hrvested. Plnt smples were then divided into two su-smples. One su-smple ws thoroughly wshed with running distilled wter to remove dust prticles nd the other remined untreted. All plnt smples were oven- dried t 8 C for 24 h, milled in micro-hmmer cutter nd fed through 1.5 mm sieve. Plnt smples were stored in clen self-seling plstic gs in silic gel. Anlyticl Techniques Aksoy A., Demirezen D. The method ws dopted from Pveley nd Dvies [14], for the nlysis of hevy metl concentrtions in soil involved qu regi digestion. One-grm smples of dried nd sieved soil mterils were shed in muffle furnce t 46 C for 24 hours. The weighed sh ws digested in 1 ml qu regi (1 HNO 3 : 3 HCl) in digestion tue on heting lock for totl of 9 hours, in the following sequence nd durtions of tempertures: 2 hrs ech t 25 C, 6 C nd 15 C nd finlly 3 hrs t 125 C. All the digested smples were centrifuged nd then mde up to volume with 1% HNO 3. The method used for plnt digestion is the sme s tht descried erlier y Al-Shye et l. [3]. One-grm smples of dry milled plnt mterils were shed in muffle furnce t 46 C for 24 hrs. The weighed sh ws digested in nlr concentrted HNO 3 nd evported to ner dryness on hot plte. Digested smples were centrifuged nd then mde up to volume with 1% HNO 3. The concentrtions of hevy metls (Cd, P, Ni, Cu, Zn nd Cr) were mesured in soil nd plnt smples y Vrin ICP-OES (Inductively Couple Plsm Opticl Emission Spectroscopy). The stndrd error vlues of the mens were clculted for the comprison of site ctegories. To determine the significnce of wshing the leves pired t- test ws performed, compring the wshed nd unwshed plnts for ech type of the sites. The reltionships etween vriles were ssessed using liner regression nd correltion nlyses. Results Led nd Cdmium The men levels of Cd nd P found in unwshed nd wshed leves of F.excelsior in different sites re presented in Figure 1-2. The urn rodside with the highest humn ctivities, together with high vehiculr density congestion, shows the highest P levels, µgg -1 which is significntly higher thn tht of the rurl sites, 8.2 µgg -1 (Fig.1 ). The results showed tht the men P levels in the rodside (14.71 µgg -1 ) ws much greter thn the P content rnge in the urn prk (12.39 µgg -1 ), industry (11.5 µgg -1 ), suurn (1.53 µgg -1 ) nd rurl (8.2 µgg -1 ) res. The urn rodside hd significntly (p<.5) higher contmintion thn the rurl one. Similr oservtions were mde y Aksoy nd Öztürk [4] nd Al-Shye et l. [3]. Fig.1 shows tht the higher levels of P re found in the urn rodside in soils (57.62 µgg -1 ). The P concentrtions in other sttions re in rodside (2.15 µgg - 1 ), urn prk (17.11 µgg -1 ), industril (14.28 µgg -1 ), suurn (12.1 µgg -1 ) nd rurl (9.12 µgg -1 ) res. Although uptke from the soil is one possile wy to rise P concentrtion in leves, Mrkert [1] suggested tht uptke of P is proly pssive nd trnsloction from root to other prts of the plnt is low, ut eril deposition nd folir uptke my contriute significntly to lef concentrtion. Wshing the leves significntly reduced the Cd concentrtion in Frxinus excelsior from ll the sites. The wshing of smples removes lrge prt of the prticles from the leves when compred to unwshed smples. The highest concentrtions of Cd in Kyseri were recorded in the plnt smples nd lso in the soil from the urn rodside (3.43 µgg -1 ) with hevy trffic nd considerle humn ctiv-

3 Frxinus Excesior s Biomonitor P concentrtion P concentrtion Cd concentrtion Cd concentrtion Fig.1. Men P concentrtions (µgg -1, dry weight) () in unwshed nd wshed F. excelsior nd () in soil, together with stndrd error rs. Fig.2. Men Cd concentrtions (µgg -1, dry weight) () in unwshed nd wshed F.excelsior nd () in soil, together with stndrd error rs. ity nd the lowest vlues were found in the rurl sites (2.2 µgg -1, Fig. 2 ). The highest men of Cd concentrtions,.428 µgg -1, in leves of the F.excelsior is significntly higher thn tht of ll the other sites except the urn sites. The men level of Cd contents in the rodside (.397 µgg -1 ) ws much greter thn the Cd content rnge in the urn prk (.362 µgg -1 ), industril (.341 µgg -1 ), suurn (.288 µgg -1 ) nd rurl (.243 µgg -1 ) res. Significntly (p <.1) elevted cdmium concentrtions were mesured in urn rodside wheres the urn prk nd industril re were lso, ut to lesser degree, contminted. The men Cd concentrtions in soils re in the urn rodside (3.43 µgg -1 ), rodside (2.92 µgg -1 ), urn prk (2.67 µgg -1 ), industril (2.71 µgg -1 ), suurn (2.34 µgg -1 ) nd rurl (2.2 µgg -1 ) res. Tle 1 shows tht the mounts of P, Cd, Zn, Cu, Ni nd Cr removed y wshing the leves were higher thn those of the rurl site, indicting tht tmospheric depositions of these metls differ in these sites. These differences re due to high nd low densities of pollutnts (trffic, industry, urning fossil fuels used in homes etc.) in study sites. In generl, higher levels of hevy metls re removed y wshing the leves in the urn rodside nd the rodside; the lower levels of hevy metls re removed y wshing in the rurl site. As seen in Tle I, % of Cd, % of P, % of Zn, % of Cu, % of Ni nd % of Cr were removed through the wshing procedure from the leves of F.excelsior. Nickel nd Copper The men concentrtions of Ni nd Cu found in unwshed nd wshed leves in different types of sites for F.excelsior Tle 1. Totl percentge of P, Cd, Ni, Cu, Zn nd Cr ws removl from the leves of Frxinus excelsior y wshing procedure. Significnce of comprison mens y ANOVA (F- test) re indicted (Key: *p<.5 nd **p<.1). Urn rodside Rodside Urn prk Industry Suurn Rurl F-test Cd ± ± ± ± ± ± 1.54 * P ± ± ± ± ± ± 1.37 * Zn ± ± ± ± ± ± 1.12 ** Cu ± ± ± ± ± ± 1.37 * Ni ± ± ± ± ± ± 1.43 * Cr ± ± ± ± ± ±.76 *

4 3 Aksoy A., Demirezen D. Ni concentrtion Ni concentrtion Cu concentrtion Cu concentrtion Fig.3. Men Ni concentrtions (µgg -1, dry weight) () in unwshed nd wshed F.excelsior nd () in soil, together with stndrd error rs. Fig.4. Men Cu concentrtions (µgg -1, dry weight) () in unwshed nd wshed F.excelsior nd () in soil, together with stndrd error rs. re presented in Figures 3 nd 4. In ddition, the men concentrtion of metls in soils supporting F.excelsior in these res is shown in Figs. 3 nd 4. The results indicted tht leves of F.excelsior could ccumulte significnt Ni nd Cu concentrtions. The concentrtions of Ni nd Cu were found to follow similr generl trend to tht for Cd with the highest vlues generlly found in the urn rodside (27.4 µgg -1, µgg -1, respectively). The highest men Ni concentrtion ws 27.4 µgg -1 nd the highest men Cu concentrtion ws µgg -1 in F.excelsior. The Ni nd Cu concentrtions in the leves of F.excelsior in the other sttions re in rodsides (24.75 µgg -1, µgg -1 ), urn prk (2.1 µgg -1, µgg -1 ), industry (21.86 µgg -1, 1.3 µgg -1 ), suurn res (16.82 µgg -1, 7.26 µgg -1 ) nd rurl re (13.42 µgg -1, 6.62 µgg -1 ). Among the sttions studied, the urn rodside, the urn prk, the rodside nd the industril site hd significntly (p <.5) elevted Ni concentrtions. In ddition, the highest men Cu nd Ni concentrtions were 21.6 µgg -1 nd µgg -1 in soil, respectively. Zinc nd Chromium The men levels of Zn nd Cr found in the unwshed nd wshed leves of F.excelsior in the different sites re presented in Figs The men zinc nd chromium concentrtions in the leves of F.excelsior, s well s in the respective soil smples, re shown in Figure 5 nd 6. The highest concentrtions of Zn nd Cr in the plnts smpled in Kyseri were recorded from the urn rodside (29.41 µgg -1 ) nd the industril site (1.7 µgg -1 ) with the influence of hevy trffic nd considerle humn ctivity. The lowest vlues were found in the rurl sites (Zn = µgg -1, Cr = 1.1 µgg -1 ). The men level of Zn contents in the rodside (23,6 µgg -1 ) ws much greter thn the content rnge in the urn prk (2.96 µgg -1 ), industril (18.72 µgg -1 ), suurn (15.68 µgg -1 ) nd rurl (13.22 µgg -1 ) sites. Significntly (p <.1) elevted zinc concentrtions were mesured in the rodside wheres the urn prk nd industril sites were lso, ut to lesser degree, contminted. The results showed tht the men level of Cr contents in the urn rodside (1.63 µgg -1 ) ws much greter thn the content rnge in the other sttions. The highest concentrtions of Zn nd Cr were found in the leves of F.excelsior (29.41 µgg -1 nd 1.7 µgg -1 ). Wshing the leves reduced the Zn nd Cr concentrtions significntly in ll the sites. Although wshing the leves reduced Zn concentrtions in ll the sites, the percentge of the element tht ws removed ws considerly lower thn Cu. In ddition, the highest concentrtions of Zn (92.64 µgg -1 ) nd Cr ( µgg -1 ) were found in soils in the urn rodside. A lest-squres liner regression nlysis ws otined for ech of the metls P, Cd, Cu, Ni nd Cr, etween the concentrtions of the element in soils nd in the wshed leves of F.excelsior (Tle 2). The results show tht the correltion coefficients (r) for Cu nd Zn were significnt t p<.1, while for Cd correltions were significnt t p<.1 nd for Ni, P nd Cr it ws not significnt in ny cse. Discussion The results indicte n increse in their concentrtions with incresing urniztion. The higher P content

5 Frxinus Excesior s Biomonitor Zn concentrtion Zn concentrtion Cr concentrtion Cr concentrtion Fig.5. Men Zn concentrtions (µgg -1, dry weight) () in unwshed nd wshed F.excelsior nd () in soil, together with stndrd error rs. Fig.6. Men Cr concentrtions (µgg -1, dry weight) () in unwshed nd wshed F.excelsior nd () in soil, together with stndrd error rs. in urn rodside soil nd plnt smples is due to trffic density, which is considered s one of the mjor sources of P contmintion s shown y mny investigtions in different countries [5, 15, 16]. Led is generlly dded to the environment y eril deposition longside the rods in proportion with the density of trffic nd the distnce from the rodside. Swidis et l. [2] studied ir pollution with hevy metls in the city of Thessloniki (Greece) using trees s iologicl indictors nd reported tht high levels of hevy metls cme from vehiculr emissions. The rte of dmge cused in the environment is gretly ffected y meteorologicl fctors, minly wind direction. Trffic emissions on rods re the min cuse of hevy metl ccumultion on the surrounding environment including vegettion, which might hve n ecologicl effect. Elevted levels of hevy metls in urn nd industrilized res re reported in mny prts of the world. Momni et l. [17] nd Scero et l. [18] hve found tht some hevy metls such s P decrese in the leves of plnts with incresing distnce from rods. The high hevy metl content in the urn sites, urn rodsides nd the soils nd plnt smples from these sites is mostly due to the density of trffic. One of the mjor sources of hevy metl contmintion, especilly P, is ecuse people use leded petrol. Depending on the pollutnt level t the collection sites, for exmple, the mount of P removed from the leves of F. excelsior y wshing ws the highest in urn rodside (46.11 %) nd it ws the lowest in the rurl sites (9.57 %). According to Al- Shye et l. [3], 26 to 68 % of P ws removed from the leves of Phoenix dctylifer y the wshing procedure. The men Cd Tle 2. Reltionships etween hevy metl concentrtion in soil nd wshed leves of Frxinus excelsior (r: correltion coefficient; *p<.1, **p<.1). Plnt Elements r Smple numer Cd.645* 48 F. excelsior Cr Cu.71** 48 P Ni Zn.72** 48 concentrtions in urn rodsides re slightly higher thn the rurl (control) site, proly indicting the ccumultion of dust rised y motor vehicles nd other humn ctivities. Wshing the leves reduced the hevy metl concentrtions significntly in ll the types of sites. Ni showed lrger effect thn Cr in this respect. A plnt folir concentrtion of.5-3 µgg -1 P hs een quoted y Dmuchowski nd Bytnerowicz [16] s criticl indictor of whether the environment is polluted with P. The results indicte tht the rodsides, urn rodsides, prks nd industril sites re seriously polluted with P. Mesnz nd Csdo [19] used the leves of Pinus rdit to study highwy hevy metl contmintion in northern Spin nd found significnt correltion etween trffic density nd forest dmge. According to Allen [2], plnts from unpolluted nturl environments

6 32 contin.1-.3 µgg -1 Cd. Frxinus excelsior exceed the upper vlue in the urn sites nd in urn prks (Fig.1). Zn is n essentil element for plnt growth nd plys n importnt role in the iosynthesis of enzymes. Norml Zn concentrtion in plnts is 15-1 µgg -1 [2]. Zinc concentrtion in the unwshed plnt smples ws linerly correlted with the trffic. Copper is essentil for growth, ut plnt concentrtions ove 2 µgg -1 re considered toxic to plnts [21]. Nrigu [22] reported tht the min sources of pollutnt copper in the tmosphere were Cu production nd hndling, fossil fuel comustion nd iron steel production. The results of this study for ll the sites did not revel high levels of pollution y Cu since concentrtions in F.excelsior plnt did not exceed the upper limit. Norml Ni concentrtion in plnts is.5-5 µgg -1. Fig. 1 showed tht concentrtions in F.excelsior plnt exceed the upper limit. Chromium is not essentil for plnt, ut plnt concentrtions ove.5 re considered toxic to plnts. Fig. 6 shows tht ll the sites chosen re highly polluted y Cr since concentrtions in F.excelsior plnt exceed the upper limit. Another notle oservtion is tht some of the sttions investigted hd high concentrtions of certin metls nd low concentrtions of other metls. In other words, sttions contining the highest concentrtions of metls mesured were not oserved. For exmple, the industril site hd the highest Cr vlue (1.7 ±.6), ut the lowest Zn vlue (18.72 ±.23) mong ll the sttions. Similr correltions were oserved y Swidis et l. [11], even when the ove dt re compred with hevy metl concentrtions from the control sttions. According to Wittig [23], some sic criteri for the selection of species s iomonitor re tht it should e represented in lrge numers ll over the monitoring re, hve wide geogrphicl rnge, e possile to differentite etween irorne nd soil-orne hevy metls, e esy to smple nd there should e no identifiction prolems. Frxinus excelsior emodies ll these criteri nd our study fully supports the view tht it cn e useful iomonitor s significnt liner regression ws otined for ech of the metls P, Cd, Cu, Zn, Ni nd Cr etween the concentrtions of the element in surfce soil nd in the wshed leves of the plnt nd ecuse it is possile to mesure the differences etween eril depositions nd root uptkes. This is supported y the findings of Sewrd nd Mshhour [24], Al-Shye et l. [3] nd Aksoy nd Öztürk [4, 5]. References 1. MARKERT, B. Plnt s iomonitors: Indıctors for hevy metls in the terrestril environment, (B.Mrkert,Ed.), VCH Weinheim, New York/Bsel/Cmridge, SAWIDIS, T., MAMASIDIS, A., ZACHARIADIS, G., STRATIS,J. A study of ir pollution with hevy metls in Aksoy A., Demirezen D. Thessloniki city (Greece) using trees s iologicl indictors. 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