A Comparative Study of Heavy Metals Concentration of Surface Soils at Metropolis Squares with High Traffic- a Case Study: Kermanshah, Iran(2015)

Acta Medica Mediterranea, 2016, 32: 891

A COMPARATIVE STUDY OF HEAVY METALS CONCENTRATION OF SURFACE SOILS AT METROPOLIS SQUARES WITH HIGH TRAFFIC- A CASE STUDY: KERMANSHAH, IRAN(2015)

MEGHDAD PIRSAHEB1, ALI ALMASI2, KIOMARS SHARAFI1,3, YAHYA JABARI2*, SOHRABALLAFPOUR HAGHIGHI2 1Research Center for Environmental Determinants of Health (RCEDH), Kermanshah University of Medical Sciences, Kermanshah, Iran - 2Department of Environmental Health Engineering, Public Health School, Kermanshah University of Medical Sciences, Kermanshah, Iran - 3Department of Environmental Health Engineering, Public Health School, Tehran University of Medical Sciences, Tehran, Iran

ABSTRACT

Background and aim: Among various soils pollutants, heavy metals have great importance due to their toxicity and adverse effect on human health and environment. Therefore the aim of this study is comparing the concentration of heavy metals in surface soil of squares with high traffic at Kermanshah metropolises in 2015. Materials and methods: For conducting this study, five high traffic area and five area as a reference soil were selected and from each location, five samples were collected. Finally a total of 50 point sample and 10 composite samples were obtained from these areas. The concentration of metals were evaluated based on the standard methods with ICP (Inductively Coupled Plasma) device. Results: The results showed that the level of heavy metals in high traffic area and reference’s soil samples were as bellow:Lead (Pb)> Nickel (Ni) > Chromium (Cr) >Vanadium (V) > Cadmium (Cd) > Selenium (Se).Also, the level of Cr, Cd and Ni in high traffic area were higher than references soil area. Conclusion: According to the results, it is necessary to take some action for controlling the pollutants emission from mobile sources in high traffic area in order to reduce the heavy metals emission in the environment.

Key words: Heavy Metals, Surface Soil, Kermanshah City, High Traffic Are.

Received February 05, 2016; Accepted March 02, 2016

Introduction the human’s health through inhalation(3). The concentration of industry in metropolises and migration of people for finding works to these cities, not only Today, heavy metal is considered as one of the caused the increased of the city’s population but most important environmental pollutants(1). The also caused the pollution of these cities. According rapid growth of urbanization and the increase of to the increased of the population’s density in cities, human’s activity have caused the changes of the for achieving to better life level, surveillances on soils composition. Today, urbanization is become a the effective factor of health and proper controlling phenomenon and more than half of the world’s pop- of them seems necessary(4, 5). The heavy metals of ulation are living in cities and according to the pre- the roadside derbies and surfaces soils of the city in diction until 2050 the city’s global population will a case of atmospheric air suspension in addition to become 68.7% of the total population(2). The growth reducing the air quality could be because of the lack of the urban population and consequently the relat- of degradation with physical process and also can ed activity such as traffic and also the heavy metals accumulated in human’s body through inhalation concentration in surface debris of cities, could and skin(6). In the roadsides derbies and city’s sur- cause the emission of the pollutants and threaten face soils, the heavy metals sources of the surface 892 Meghdad Pirsaheb, Ali Almasiet Al soils were include traffic (the exhaust particle, rub- ber particles, street particles, and brake pads coated particles), the emission of industrial activities (the emissions from the industrial process, the exhaust fuel gases), household emissions (fuel combustion for cooking and heating) and particles of buildings erosion and construction, human’s activity such as waste producing and using sewage’s sludge, pesti- cides and dust of the side walk and atmospheric deposits(7-11, 3). Olukanni et al. in Ota metropolise of Nigria (2012) evaluated the effect of the heavy metals such as Copper (Cu), Cd, Pb, Manganese (Mn), Figure 1: The location map of the Kermanshah city in Ni ans Sulpfate which emmited from vehicals to Iran. soils and concluded that, the level of the above Latitude Longitude Sampling Sample Code heavy metals in high trafficarea was higher than the low traffic area(12). Soltani et al. (2015) in Isfahan 34.32388 47.072933 Azadi Square A-1 found that, traffic is the main effective source in 34.348356 47.087741 Markazi Square A-2 dust pollution of the street and the level of the Arsenic (Ar), Cd, Cu, Pb and Znic(Zn) increased 34.381662 47.129995 Maskan Square A-3 (13) Mosaddegh significantly . Mafuyai et al. (2015) in Jos metrop- 34.304984 47.061794 A-4 olise of Nigiria showed that the accamulation of Square heavy metals such as Cu, Pb, Ni, Zn, Ferous (Fe), 34.312245 47.067019 Ojagh Square A-5

Cd, Mn and Cr in dust of the roadside significantly 34.400702 47.129015 Mountain Taq B-1 affected by high traffic and the metal concentration 34.491739 46.603128 Plain Kuzaran B-2 is reduced significantly by increasing the distance from road(14). Therefore, surfaces soils and debrise 34.269277 46.795558 Plain Mahidasht B-3 of the city’s roadside are good index for presenting the pollution of the heavy metals(15). Therefore, the 34.280219 47.117783 Faraman area B-4 aim of this study is to evaluate the comparison of 34.385941 47.055656 QanbarSarab area B-5 the heavy metals concentration in surfaces soils of high traffic area in Kermanshah metropolise with Table 1: Sampling point characteristic. the away area fromtown and pristine area. Table Sampling method Marerial and methods First five high traffic region of the city and five references region out of the city which have The geographicall location of the studied not traffic and vehicles were selected. Then from area each high traffic square and selected reference This study had been conducted in Kermanshah region, five points (each with the area of 1 m 3) metropolice, Iran’s ninth most populous city and were selected for surface soil sampling. Also the capital of Kermanshah province, which has the surface soil in special point were collected and population of over 851405 people and an area of stored by shovel, pickaxe and sweep in the depth of 93389956 m3. Kermanshah is the Kurdistan’s large the (0-20) cm. the samples which taken from the city and the most important city in the centeral above points, were combined and a composite sam- region of west (Figure 1)(16). ples were prepared from them. Based on this fact from each region, five composite samples were pro- Smpling sites and area vided and a total of 10 composite sample (50 point First five region with high traffic from city’s sample) were collected. The collected samples were square and then five region as area with reference transferred to the lab under the standard condition (17, 10, 6, 3) soil (which is not affected by any polluted source) in poly ethylene bags . were selected. Each application were coded based ??? Preparation and extraction of the samples First the samples were milled by mortar and sieved by the (20 mesh) labratory’s sieve. Then the A comparative study of heavy metals concentration of surface... 893

samples were placed in the oven for 24 hour in 60± The Number of Heavy Metal Sampling Location Mean ± SD P-value 5°C(8, 11). Half gram of the soil sample placed in a Sample test tube and then 6 ml HCL with the concentration Azadi Square 3 4.05±0 of 30% and 2 ml HNO3 with the concentration of Markazi Square 3 4.05±0 65% and 3 ml concentrated HCLO3were aded to it. Maskan Square 3 3.15±0 Then the prepered mixture was placed in the oven Cd 0.17 for six hours in 90°C. After cooling the mixture, Mosaddegh Square 3 3.25±0 each of them were filtered by using Whatman 42, Ojagh Square 3 3.4±0

Ashless 42.5mm, 1442 042 Filter Paper and then Total 15 3.58±0.41 poured in a 25 lit balloon and volume to 25ml with Azadi Square 3 33.1±0.5 a distilled water ( six times distillation)(19). The prepared mixture was injected to the ICP device Markazi Square 3 37.15±1 (Perkin elmer 7300 DV) and the concentration of Maskan Square 3 32.4±0.5 V <0.001 the heavy metals such as Cd, V, Cr, Se, Ni, Pb, were Mosaddegh Square 3 33.25±1 evaluated. The detection limit of atomic spec- Ojagh Square 3 31.95±1 troscopy device for Cd, V, Cr, Se, Ni and Pb were Total 15 33.57±2.04 respectively, 0.1, 0.5, 0.2, 2, 0.5, 1 ppb or µg/l. Azadi Square 3 113.6±4

Samples analysis by ICP Markazi Square 3 121.65±4

The atomic emission spectroscopy method is Maskan Square 3 109.5±3.5 based on the using of ICP as a source of agitation Cr <0.001 Mosaddegh Square 3 72.35±3 for quantitive and qualitive analysis of the elements. In this method a stream of Argon gas was Ojagh Square 3 114.8±4 ionized by a magnetic field with radio frequency of Total 15 106.38±18.34

27-40 MHz and produced a thermal of 1000 °K. Azadi Square 3 Nd* The samples were sprayed to the Argon plasma by a nebulized and turned to the atomic particle (ions) at Markazi Square 3 Nd high temperature and create their emission. The Maskan Square 3 Nd Se (20) level of the emission evaluated by device . Mosaddegh Square 3 Nd

Ojagh Square 3 Nd Statistical analysis The raw data which obtained from the ICP Total 15 Nd device and were defined by ppm, turned into mg/kg. Azadi Square 3 292.15±4.5 Then by using excel and SPSS software the central Markazi Square 3 344.05±4 index (average, median, mean) and the dispersion Maskan Square 3 237.5±2.5 index (field changes, mean deviation, variance and Ni <0.001 Mosaddegh Square 3 206.6±3 standard deviation) was calculated. The average concentration of each heavy metals among various Ojagh Square 3 308.8±2.5 application and also the average concentration of the Total 15 277.82±51.31 various heavy metals with each other in particular <0.001 Pb Azadi Square 3 484±6 application were compared with one-way ANOVA test in a significant level (α=0.05). in addition to it, Markazi Square 3 618±9 the average concentration of each evaluated heavy Maskan Square 3 430.1±8 metal in a particular application were compared with the average concentration of heavy metal in the ref- Mosaddegh Square 3 431.2±9.5 erence soils sample and also compared with the stan- Ojagh Square 3 482.3±7 dard by statistical One sample T-test in a significant level (α= 0.05). In variance analysis for calculating Total 15 489.12±71.32 the differences between the groups, the Tukeytest Table 2: Concentrations of heavy metals in topsoil of were used. high-traffic areas in Kermanshah(mg/kg). Nd*: Non detectable 894 Meghdad Pirsaheb, Ali Almasiet Al

Results The Number of Heavy Metal Sampling Mean ± SD P-value Sample The concentration of the heavy metals in the Mountain Taq 3 6.25±0 evaluated high traffic areas Plain Kuzaran 3 5.9±0

The results showed that there isn’t a significant Plain Mahidasht 3 6.55±0 Cd 0.04 difference between the average level of Cd in five Faraman area 3 2.8±0 different area (with high traffic application) (P>0.05). But there is a significant difference QanbarSarab area 3 3.9±0 between the V, Ni, Cr, Pb, level (P<0.05) in a way Total 15 5.08±1.52 that the most level of V is related to the Ojagh inter- Mountain Taq 3 49.6±1.5 section and also the least level of Cr, Ni, Pb, is relat- Plain Kuzaran 3 48.2±1.5 ed to Mosadegh square. The Se non-mental level in Plain Mahidasht 3 47.45±1 all high traffic applications was zero (Table 2). V <0.001 Faraman area 3 39.15±1

Concentration of the heavy metals in refer- QanbarSarab area 3 43.3±1 ences soils samples Total 15 45.54±4.09

According to the obtained results, there is a Mountain Taq 3 148.75±3.5 significant difference between the level of Cd, V, Plain Kuzaran 3 102.7±3 Cr, Ni, and Pb in five various region (P<0.05) in a Plain Mahidasht 3 110.2±2.5 Cr <0.001 way that the most level of Cd and Cr were related Faraman area 3 53.4±2.5 to the Taq-Bostan mountain and the least level of QanbarSarab area 3 74.2±3 Cd, V, Cr, Ni and Pb were in the Faraman region. Total 15 97.85±33.8 The level of the Se non-mental in all parks and green space applications except Taq-Bostan Mountain Taq 3 1.15±0 Mountain was zero (Table 3). The average concen- Plain Kuzaran 3 Nd* tration of the Pb, V, Se in references soils samples Plain Mahidasht 3 Nd were more than high traffic area and the concentra- Se - tion of the Cr, Ni, Cd in high traffic area were more Faraman area 3 Nd than references soils samples (Figure 2). QanbarSarab area 3 Nd

Based on the founding there isn’t a significant Total 15 0.23±0.48 differences between the average level of Cd, V, Cr, Mountain Taq 3 137.85±1.5 Ni, Pb and Se non-mental in high traffic area and references soils samples (P>0.05) (Table 4). Plain Kuzaran 3 127.45±2

Plain Mahidasht 3 139.95±1.5 Discussion Ni <0.001 Faraman area 3 68.75±1

In high traffic area the average concentration QanbarSarab area 3 92.7±2 level of heavy metals such as Cd, V, Cr, Se, Ni, and Total 15 113.34±29.02 Pb were respectively, 3.58, 33.57, 106.38, 0, 277.82, 489.12 mg/kg. In this application there was Mountain Taq 3 914±8 a significant difference between the level of V, Cr, Plain Kuzaran 3 934±12.5

Ni and Pb (P<0.05) in a way that the most level of Plain Mahidasht 3 1101±17 Pb <0.001 V, Cr, Ni and Pb were related to the Markazi square Faraman area 3 341.95±3.5 and the least level of the Cr, Ni, and Pb were related QanbarSarab area 3 558.5±5.5 to the Mosadegh square. The incessant traffic of vehicles in the Total 15 769.89±287.42 Markazi square and the smoke of the exhaust, tire Table 3: Concentrations of heavy metals in in soil sam- wear and oil and gasoline of the old vehicles proba- ples reference (mg/kg). bly caused the increased of the heavy metals con- Nd*: Non- detectable to having high traffic, because of its special loca- centration in surface soils of this square. This tion and other applications such as park and green square which have the most population, inadittion space, commercial and small-scale industry have A comparative study of heavy metals concentration of surface... 895 significant effect on pollution and increased the sion of the natural rocks, also deposite of the concentration of pollutants. volotile particle which contain heavy metals could cause the penetration of heavy metals in the surface Sampling area Cd V Cr Se Ni Pb soils in away region and pristine area. Smolders et

High-traffic areas 3.58 33.57 106.38 ND 277.82 489.12 al. study (1999) haveconducted on the Belgiums soil and determined the concentration level of Cd in Reference areas 5.08 45.54 97.85 0.23 113.34 769.89 the earths crust 0.1-1 mg/kg(22). While the average

P-value 1 1 1 1 0.961 0.614 level of Cd in reffrences soil of Kermanshah was Table 4: Compares the average concentrations of heavy 5.08 mg/kg which in comparison with Smolders metals in top-soilat high-traffic areas with reference study and according to the suggestion of the CCME areas (mg/kg). ( Canadian council of Minister of Environmen) and control and monitoring standard of Tiwan, the level of the Cd id higher. Based on the ranking of the elements frequency at the earths crust in 20 century, the average concentration of V was 110 mg/kg(23). In the other studies the average level was reported 150 mg/kg(24) and in some other studies the level of V was reported in the range of 98-230 mg/kg(25). While the level of V in the Kermanshahs reference soil was 45.54 mg/kg. according to the CCME the level of V was lower. Based on the Alloway (1995) study, the average level of tht Cr in the earths crust was 110 mg/kg and based on the Figure 2: Compares the average concentrations of heavy Kabata (2010) report, the level of the Cr in the ref- metals in high-traffic areas with reference areas (mg/kg). erence and natural soil was 122mg/kg(26, 27). The average level of Cr in Kermanshahs reference soil Based on the studies which have done by was 97.85 mg/kg which in comparison with the Chen et al. (2010) in the roadsides soils and ring above studies and control and monitoring standards road of Beijing in china, they evaluated that the of Tiwan the level of Cr was lower and according to average concentration level of heavy metals such as the CCME suggestion the level of the Cr was high- Cd, Cr, Ni, Pb, were respectively 0.215, 61.9, 26.7, er. With regard to the Fordyce and Selinus (2013) 35.4 mg/kg. and also the obtained level was com- studies the level of the Se in worlds soil was in the pared with the similar soil of other cities in the range of 0.01-2 mg/kg and the average of it was 0.4 world(21). According to the establishment of high mg/kg and its frequency at the earths crust was traffic squares in areas with commercial applica- 0.05-09 mg/kg(28, 29). tions and also with comparison of the suggested And according to the fact that the concentra- concentration by the Canada environment Official tion range of Se in the Kermanshah reference soil the level of the Cd, V, Se were low and the concen- was 0.23 mg/kg, this level in comparison with the tration level of CR, NI and Pb were high. In the ref- above studies seems desirable. The level of Ni in erences soils samples the average concentration worlds soil based on the Shacklette (1984) report level of heavy metals such as Cd, V, Cr,Se,Ni and was in the range of 0.2-450 mg/kg(30). And also it Pb were respectively, 5.08, 45.54, 97.85, 0.23, was consistent with Adriano studies (2001) and its 133.34, 769.89 mg/kg. in this application there was frequency at the earths crust was 80 mg/kg(31). This a significant difference between the average level level, in comparison with the Ni level in of Cd, V, Cr, Ni, Pb (P<0.05) in a way that the most Kermanshah refrence soils was similar with the level of Cd, Ni and Pb were related to the average level of 113.34 mg/kg in the Shacklette Mahidasht plain and the most level of the V and Cr study. But its level was higher than the average were related to the Taq-Bostan Mountain. level of earth crust. In comparison with the above In the references application and and away studies and according to the CCME suggestion the area from pollutants, the natural source polluted the level of Ni was higher and based on the control and soil with heavy metals more than the artificials monitoring standard of Tiwan the level of Ni was source such as precipitation, wind errosion, erro- lower. 896 Meghdad Pirsaheb, Ali Almasiet Al

In Wedepohl (1995) evaluation the frequency 5) Fakayode S, Olu-Owolabi B. Heavy metal contamina- of the Pb level in earth crust was reported 14.8 tion of roadside topsoil in Osogbo, Nigeria: Its rela- (32) tionship to traffic density and proximity to highways. mg/kg . Also, Nriagu (1978) presented the average Environmental Geology. 2003; 44(2): 150-7. level of Pb in unpolluted soil in all the world 6) Lu Y, Gong Z, Zhang G, Burghardt W. Concentrations 17mg/kg(33). This level is confiemed for Pb in the and chemical speciations of Cu, Zn, Pb and Cr of reference soilby more studies(30, 34-36). In some soil urban soils in Nanjing, China. Geoderma. 2003; studies in large scale the level of the Pb was high- 115(1): 101-11. 7) Benhaddya ML, Hadjel M. Spatial distribution and (37,38) er but there are some evidences which showed contamination assessment of heavy metals in surface that the observed Pb in most of the soil is originated soils of Hassi Messaoud, Algeria. Environmental Earth from human activity(40, 41). The level of the Pb in Sciences. 2014; 71(3): 1473-86. Kermansah reference soils was 769.89mg/kg in 8) Škrbić B, Đurišić-Mladenović N. Distribution of heavyelements in urban and rural surface soils: the comparison with above studies and according to the Novi Sad city and the surrounding settlements, Serbia. CCME suggestion the level of the Pb was higher Environmental monitoring and assessment. 2013; and based on the control and monitoring standard 185(1): 457-71. of Tiwan the level of Pb was lower. 9) Andersson M, Ottesen R, Langedal M. Geochemistry of urban surface soils-monitoring in Trondheim, Norway. Geoderma. 2010; 156(3): 112-8. Conclusion 10) Xia X, Chen X, Liu R, Liu H. Heavy metals in urban soils with various types of land use in Beijing, China. The results of the study showed that the Journal of Hazardous Materials. 2011; 186(2): 2043-50. changes level of the studied heavy metals in high 11) Zhang X, Lin F, Wong MT, Feng X, Wang K. Identification of soil heavy metal sources from anthro- traffic area and reference soil samples were as bel- pogenic activities and pollution assessment of Fuyang low:Pb> Ni> Cr> V> Cd> Se. In addition to it the County, China. Environmental monitoring and assess- results showed that the concentration level of heavy ment. 2009; 154(1-4): 439-49. metals such as Cr, Cd, Ni, in high traffic area were 12) Olukanni DO, Adebiyi SA. Assessment of vehicular higher than reference soil samples. While this is pollution of roadside soils in Ota Metropolis, Ogun State, Nigeria. International Journal of Civil & opposite for other metals. Se non-mental observed Environmental Engineering IJCEE-IJENS. 2012; 12(4): in reference soils samples, but it has not determined 40-6. in high traffic area. According to the dangerous 13) Soltani N, Keshavarzi B, Moore F, Tavakol T, aand polluting role of the heavy metals in environ- Lahijanzadeh AR, Jaafarzadeh N, et al. Ecological and human health hazards of heavy metals and polycyclic ment and human health, monitoring of their con- aromatic hydrocarbons (PAHs) in road dust of Isfahan centration in surface soil of the side walk in city metropolis, Iran. Science of the total environment. (particularly high traffic area) has a great impor- 2015; 505: 712-23. tance and also editing the limitation standard from 14) Mafuyai G, Kamoh N, Kangpe N, Ayuba S, Eneji I. the responsible health and environmental official Heavy Metals Contamination in Roadside Dust along Major Traffic Roads in Jos Metropolitan Area, Nigeria. seems neccesary. Journal of Environment and Earth Science. 2015; 5(5): 48-57. 15) Li X, Poon C-s, Liu PS. Heavy metal contamination of urban soils and street dusts in Hong Kong. Applied Geochemistry. 2001; 16(11): 1361-8. References 16) Statistical Center of Iran, population and housing cen- sus. 2011. 1) Pirsaheb M, Khosravi T, Sharafi K, Babajani L, Rezaei 17) Morton-Bermea O, Hernández-Álvarez E, González- M. Measurement of Heavy Metals Concentration in Hernández G, Romero F, Lozano R, Beramendi-Orosco Drinking Water from Source to Consumption Site in L. Assessment of heavy metal pollution in urban top- Kermanshah-Iran. World Applied Sciences Journal. soils from the metropolitan area of Mexico City. 2013; 21(3): 416-23. Journal of Geochemical Exploration. 2009; 101(3): 2) Luo X-s, Yu S, Zhu Y-g, Li X-d. Trace metal contami- 218-24. nation in urban soils of China. Science of the Total 18) Batjargal T, Otgonjargal E, Baek K, Yang J-S. Environment. 2012; 421: 17-30. Assessment of metals contamination of soils in 3) Wei B, Yang L. A review of heavy metal contaminations Ulaanbaatar, Mongolia. Journal of hazardous materi- in urban soils, urban road dusts and agricultural soils als. 2010; 184(1): 872-6. from China. Microchemical Journal. 2010; 94(2): 99- 19) Tüzen M. Determination ofheavy metals in soil, mush- 107. room and plant samples by atomic absorptionspectrom- 4. Goveia DE. An Analysis of the Potential Risk Exposure etry. Microchemical Journal. 2003; 74(3): 289-97. to Lead (Pb) through Urban Community Gardens. 20) Barnard TW, Crockett MI, Ivaldi JC, Lundberg PL, 2013. Yates DA, Levine PA, et al. Solid-state detector for A comparative study of heavy metals concentration of surface... 897

ICP-OES. Analytical Chemistry. 1993; 65(9): 1231-9. 39) Davies BE, Wixson BG. Use of factor analysis to dif- 21) Chen X, Xia X, Zhao Y, Zhang P. Heavy metal concen- ferentiate pollutants from other trace metals in surface trations in roadside soils and correlation with urban soils of the mineralized area of Madison County, traffic in Beijing, China. Journal of hazardous materi- Missouri, USA. Water, Air, and Soil Pollution. 1987; als. 2010; 181(1): 640-6. 33(3-4): 339-48. 22) Smolders E, Brans K, Földi A, Merckx R. Cadmium 40) Siccama TG, Smith WH. Lead accumulation in a fixation in soils measured by isotopic dilution. Soil northern hardwood forest. Environmental Science & Science Society of America Journal. 1999; 63(1): 78- Technology. 1978; 12(5): 593-4. 85. 41) Steinnes E, Allen R, Petersen H, Rambæk J, Varskog P. 23) Peterson P, Girling C. Other trace metals. Effect of Evidence of large scale heavy-metal contamination of heavy metal pollution on plants: Springer; 1981. p. natural surface soils in Norway from long-range 213-78. atmospheric transport. Science of the Total 24) Zenz C. Vanadium. Academic Press, New York, USA; Environment. 1997; 205(2): 255-66. 1980. p. 293-327. 25) Reimann C, De Caritat P. Chemical elements in the environment: factsheets for the geochemist and environmental scientist: Springer Science & Business Media; 2012. 26) Kabata-Pendias A. Trace elementsin soils and plants: CRC press; 2010. Acknowledgement 27) Alloway BJ. Heavy metals in soils: Springer Science & This letter resulted from Yahya Jabari’s thesis, Major Business Media; 1995. Environmental Health Engineering, Kermanshah University of 28.) Fordyce FM. Selenium deficiency and toxicity in the Medical Science, Kermanshah, Iran.The authors wish to environment: Springer; 2013. acknowledge the financial support of carrying out this project 29) Selinus O, Alloway BJ, Centeno JA, Finkelman RB, (Grant Number:933366) from Kermanshah University of med- Fuge R, Lindh U, et al. Essentials of medical geology: ical sciences. Springer; 2013. 30) Shacklette HT, Boerngen JG. Element concentrations in soils and other surficial materials of the contermi- nous United States. USGPO, 1984, 2330-7102. 31) Adriano DC. Introduction: Springer; 2001. 32) Wedepohl KH. The composition of the continental crust. Geochimica et cosmochimica Acta. 1995; 59(7): 1217-32. 33) Nriagu JO. Biogeochemistry of Lead in the Environment: Elsevier/North-Holland Biomedical Press; 1978. 34) Kabata-Pendias A, Dudka S. Baseline data for cadmium and lead in soils and some cereals of Poland. Water, Air, and Soil Pollution. 1991; 57(1): 723-31. 35) Lado LR, Hengl T, Reuter HI. Heavy metals in European soils: a geostatistical analysis of the FOREGS Geochemical database. Geoderma. 2008; 148(2): 189-99. 36) Reaves G, Berrow M. Extractable lead concentrations in Scottish soils. Geoderma. 1984; 32(2): 117-29. 37) Chen T, Zheng Y, Chen H, Zheng G. Background concentrations of soil heavy metals in Beijing. Huan jing ke xue= Huanjing kexue/[bian ji, Zhongguo ke xue yuan huan jing ke xue wei yuan hui" Huan jing ke xue" ______bian ji wei yuan hui]. 2004; 25(1): 117-22. Corresponding author 38) Davies BE. A graphical estimation of the normal lead [email protected] content of some British soils. Geoderma. 1983; 29(1): (Iran) 67-75.