soil/sediment contamination in northeastern tunisia: a...

Solid Waste Landfill and Soil/Sediment Contamination: Case Studies in Tunisia, p.53-84. © 2002, INRST-JICA

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Soil/Sediment Contamination in northeastern Tunisia: A preliminary result on the spatial variation of potentially toxic elements Mitsuo Yoshida, Hamadi Kallali and Ahmed Ghrabi Laboratoire Eau & Environnement, Institut National de Recherche Scientifique et Technique Abstract The concentration of 37 elements including tracemetals and other potentially toxic elements (PTEs) were determined in the surface soil samples collected from Tunis – Cap Bon – Hammamet – Enfida – Zaghoan area, northeastern part of Tunisia. Based on the results of statistical analysis, natural background value was estimated for the area (Table 4). The concentrations of PTEs generally do not exceed the critical levels for preventing toxicity problems in human that were defined by the total content-based quality standards, however the soil/sediment distributed nearby industrial zone, urban area, and solid waste disposal sites (‘hotspots’ in Tunis urban zone and its surroundings) often shows abnormal high concentration of seven PTEs, As, Cd, Cu, Hg, Pb, Sb, and Zn. Those contaminations are probably caused by human activities and pollution of mismanaged solid waste disposal sites. Keywords PTEs, Soil contamination, Screening, Background I. Introduction

Environmental background values are used to determine if a soil has become

enriched with an undesirable substance, such as heavy metals and other toxic elements. Such soils with values exceeding the local background are then regarded as contaminated. If the soil becomes so contaminated that it has an observed environmental impact, it deemed polluted. The level at which a soil is deemed polluted therefore depends on the contaminant of interest, its bioavailability and toxicity, and the pathways on which human health is exercised. The regulation values or environmental quality standards (EQS) on soil contamination should be defined based on these considerations. However, systematic investigation of background values of Tunisian soil have not been carried out so far.

The project, named ‘Environmental Geochemical Mapping Project (EGMAP)’, is initially designed for determining the background values of heavy metals and other potentially toxic elements (PTEs) within Tunisian soils on the basis of a systematic sampling grid that will be defined by GPS (Global Positioning System) in practice. At the same time, the project is also designed as an environmental screening work to extract such soil zones showing abnormal values that are possibly caused by anthropogenic pollutions. Thus the monitoring results obtained would make possible to argue environmental impacts by human activities and a risk assessment in the territory.

Present project can be regarded as a ‘Phase I’ in a wider projects frame (mega-project), which might be followed by three-phase projects in ascending order: Phase I: Low density monitoring and pilot study in Northern Area, Phase II: Monitoring all over the land in Tunisia, Phase III: High density monitoring for anomalous zones extracted by the Phases I and II, Present project (Phase I) was launched in February 2001, as following timetable:

- Field sampling: February-April 2001 - Laboratory analyses: March 2001 – March 2002 - Data handling and interpretation: January-June 2002 - Reporting (publication and seminar): July 2002 - Establishing a pilot GIS: April 2002 -

Part II. Soil/Sediment Contamination

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Since February 2001, we are conducting a project (Phase I) on systematic sampling of

surface soil and sediment distributed in the northern Tunisia. The soil/sediment samples collected were chemically analysed in laboratory, and the concentration of 37 trace elements were determined for environmental pollution monitoring in the region (Yoshida and Kallali, 2002). On the basis of obtained data, not only the contaminated part was screened but also the natural background level of PTEs concentration was estimated. The results will be compiled on a geographic information system (GIS) for further interpretation (Chabaane et al., 2002).

In this paper we report analytical results and preliminary interpretation on the survey of north eastern part of Tunisia; Tunis – Cap Bon – Hammamet – Enfida – Zaghoan area.

II. Sampling Scheme The sampling was made based on 7.5’ (approx. 13.8km) x 7.5’ (11.1 km) grid defined on 1/200,000 topographic map in advance as shown in Figure 1. Each sampling site was identified using the Global Positioning System (GPS).

Figure 1: A plan of grid scheme For each grid at least one soil/sediment samples which can represent predominant soil/sediment in the grid area. If a grid area includes populated area, industrial zone, solid waste landfill, and/or other potential polluters, the potentially-contaminated soil/sediment were collected from the site. Field description was made as the folw chart as shown in Figure 2.

N-S 7.5’ (approx. 13.8 km)

E-W 7.5’ (approx. 11.1 km)

Longitude

Latitude

Spatial distribution of PTEs

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Figure 2: Procedure of field description, sampling, and measurement in a given site

Site selection in given grid

Determination of latitude and longitude using GPS

Name of the place, other geographic information

Land use ?

Nature ?

Soil/sediment type?

Groundwater sampling if available

Field description and sampling using 5 point mixing method

In situ magnetic susceptibility measurement

Interview with local people or land owner - Name of the place - Environmental problem - Other geographical information

- Agriculture - Residential - Urban - Industrial - None - Others - Forest

- Plain - Hills - Dessert - Salt lake- Beach - Others

Data Sheets Water samples

Soil/sediment samples

- Natural sediment - Natural soil - Agricultural soil - Urban soil - Waste-related soil- Others


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Table 1: List of sampling site in the 1/200,000 map NJ-32-V ‘Tounis’

Site ID Place Latitude (N) Longitude (E) Land use Nature Soil type ordegree minute degree minute Water type

5-01a Sidi Thabet 36 54.43 10 3.05 agriculture plain agri soil5-02a Garaat Bouhnash (Raoued) 36 57.91 10 8.59 agriculture plain agri soil5-02b Jabel Nahli 36 53.62 10 8.88 agriculture plain natural5-02c Hissiene village 36 60.26 10 10.41 residential salt lake natural5-02d Sokra 36 52.94 10 14.24 residential plain natural5-02f Raoud plage (Cite des Juges) 36 57.27 10 10.68 agriculture irrigation canal draged sediments in canal5-02g Borj Touil 36 55.62 10 8.30 agriculture plain agri soil5-02h Borj Touil wastewater irrigation area 36 55.65 10 7.97 agriculture plain agri soil5-02i Borj Touil irrigation area 36 55.52 10 7.93 agriculture plain agri soil5-03a Ras Gammarth 36 54.63 10 19.14 tourist zonebeach natural5-03b Gammarth 36 55.90 10 15.82 tourist zonesalt lake natural5-06a Bir Ejjedi 36 55.57 10 50.32 agriculture field agri soil5-06b1 Tazoghran 36 52.97 10 45.59 forest hills natural -15cm5-06b2 Tazoghran 36 52.97 10 45.59 forest hills natural -100cm5-07a Sidi Dawid 36 57.96 10 54.74 agriculture plain agri soil5-08a Hay az-Zohour 36 47.27 10 6.73 urban plain urban5-08b Bejawa 36 51.88 10 0.03 agriculture plain agri soil5-09b Henchir El Yahoudia 36 44.13 10 10.65 MSW landf plain reclaimed capsoil5-09c Tunis Cartage Airport 36 50.94 10 12.75 urban plain urban5-09d Nassr City 36 51.33 10 9.24 urban plain natural5-09e El Khadra 36 49.88 10 11.67 urban plain urban5-09f Belvedere Park 36 49.07 10 10.59 urban plain urban5-10a Rades El Mallaha 36 46.13 10 15.79 industrial plain natural5-10b Rades Port 36 48.15 10 16.58 industrial beach lagoon sediment5-10c Port puniques Cartage 36 50.67 10 19.54 residential beach lagoon sediment5-10d Rades Sud 36 45.67 10 16.41 urban plain urban5-10e Rades 36 47.34 10 16.52 industrial plain urban5-10f Rades (near the thermal power plant) 36 47.55 10 16.84 industrial plain natural5-10g Rades Ferry Port 36 48.55 10 17.11 industrial plain natural5-10h La Goulett 36 48.79 10 17.42 industrial plain urban5-10i Ain Zaghouan 36 50.74 10 17.14 residential plain lagoon sediment5-11a Dwala 36 50.13 10 35.72 forest forest natural5-12a Sidi Aissa 36 49.91 10 40.63 agriculture plain agri soil5-13a Al Mida nord 36 46.09 10 51.25 agriculture plain agri soil5-14a Menzel Temin nord 36 49.68 10 58.37 agriculture plain agri soil5-16d Mohamedia 36 40.64 10 9.44 urban plain urban5-17a Hammam-Lif (Houumt Saboun) 36 43.87 10 20.60 residential plain natural5-17b Hammam-Lif corniche 36 43.93 10 20.43 residential plain natural5-17d Mornag 36 41.70 10 16.67 agriculture plain agri soil5-17e Hmed Zeid 36 38.28 10 18.15 residential plain urban5-17f Ez Zahra 36 44.48 10 18.12 residential plain urban5-17g Hammam-Lif (Closed mine industry) 36 43.33 10 20.29 industrial plain urban5-17h Hammam-Lif 36 43.32 10 20.36 residential plain natural5-17i Hammam-Lif 36 43.55 10 20.33 urban plain urban5-17j Mornag (INAT farm) 36 41.15 10 15.17 agriculture plain agri soil5-17k Mornag (INAT farm) 36 41.18 10 15.20 agriculture plain agri soil5-18a Borj Cedria (LEE-INRST) 36 42.52 10 25.57 residential plain urban5-18b Soliman plage (Sebkhat el Malah) 36 43.52 10 28.23 residential salt lake lagoon sediment5-18c Touta village 36 38.52 10 28.64 agriculture plain agri soil5-18d1 Halloufa Jebel 36 40.19 10 25.93 forest plain natural5-18e Soliman (MSW landfill) 36 43.04 10 29.00 residential plain natural5-19a Menzil Bou Zalfa 36 41.41 10 30.76 industrial plain natural5-20a Charfine 36 40.75 10 42.18 agriculture plain agri soil5-21a Ohm Dhwil 36 43.44 10 48.71 agriculture plain agri soil5-22a Libna 36 42.65 10 55.49 agriculture plain agri soil5-23a Jabil al Wost 36 32.23 10 4.45 barren plain natural5-25a Jabil Rsas 36 38.10 10 19.10 agriculture plain agri soil5-26a Grombalia 36 36.23 10 29.70 urban plain urban5-26b Ain Tebornig 36 33.26 10 27.38 agriculture plain agri soil5-26c Sidi Bahr 36 30.83 10 25.09 agriculture plain agri soil5-27a Belli 36 34.18 10 32.97 agriculture plain agri soil5-28a Boujrida 36 35.46 10 41.92 agriculture plain natural5-29a Korba 36 33.87 10 51.25 urban plain urban5-31a Sminja East 36 27.28 10 3.84 agriculture plain agri soil5-32a Zagouan 36 24.47 10 11.90 agriculture plain agri soil5-33a Jabel Sidi Zid 36 27.12 10 16.74 forest hills natural5-34a Hammam Jedidi 36 23.67 10 22.87 industrial hills mine waste5-34b Sidi Jedidi 36 25.14 10 26.71 agriculture hills natural


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Table 1 (continued): List of sampling site in the 1/200,000 map NJ-32-V ‘Tounis’ II. Analysis

A 15.0 gm sample split was digested in 90 mL aqua regia (HCl-HNO3-H2O) at 95°C for one hour. The solution is diluted to 300 mL with distilled water. Analysis was made by an Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) and Mass Spectrometry (ICP-MS). Total 37 elements were measured: B, Na, Mg, Al, P, S, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Sr, Mo, Ag, Cd, Sb, Te, Ba, La, W, Au, Hg, Tl, Pb, Bi, Th, and U. The upper detection limit for Ag, Au, Hg, W, Se, Te, Tl, and Ga is 100 ppm, that for Mo, Co, Cd, Sb, Bi, Th, U, and B is 2 %, and that for Cu, Pb, Zn, Ni, Mn, As, V, La, and Cr is 10 %. The aqua regia digestion of sediment or sludge extracts only a fraction of the major elements (pseudo-total analysis) because silicates are not completely dissolved with this method. Owing to this limitation, results are total to near total for trace and base metals and possibly partial for rock-forming elements such as Na, Mg, Al, K, Ca, Mn, and Fe. However, environmentalily concerned components like heavy metals or PTEs not bound to silicates are efficiently dissolved (Ure, 1995), which is indicative for the assessment of toxicity. III. Results

The results of PTEs analysis using aqua regia extraction method are summarized in Tables 2(1) and 2(2), and the concentration level of each element is illustrated as box & whisker plots in Figure 3. In general, the variation of concentration depends on soil/sediment type. The bivariate histograms for each element are shown in Figures 4(1) –4(6). For selected PTEs, As, B, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Sb, Se, and Zn, the spatial variation of soil/sediment contamination is respectively shown in 3D surface diagram as Figures 5(1) – 5(14). The variation of magnetic susceptibility of the surface soil/sediment also shown in Figure 6.

Site ID Place Latitude (N) Longitude (E) Land use Nature Soil type ordegree minute degree minute Water type

5-35a Hammamet (bus terminal) 36 24.23 10 33.60 urban plain urban5-36a Nabeul 36 26.89 10 43.18 urban plain urban5-37a Bni Khyar 36 28.51 10 47.42 agriculture plain agri soil5-38a Kaf Azzayyiz 36 15.94 10 3.34 agriculture plain agri soil5-39a Zriba 36 21.26 10 13.32 agriculture hills natural5-39c Zriba Hammam 36 20.65 10 12.48 industrial hills F mine waste5-40a Bou Ashir 36 19.51 10 21.25 agriculture plain agri soil5-41a Bouficha 36 18.32 10 26.36 agriculture plain agri soil5-42a Bouficha nord 36 19.29 10 29.47 agriculture plain agri soil5-43a Khadra 36 10.53 10 2.88 agriculture plain agri soil5-44a Saouaf 36 12.70 10 11.20 agriculture plain agri soil5-46b Ash Shhgarniyya 36 11.00 10 25.57 agriculture plain agri soil5-47a Sidi Neji 36 3.28 10 3.08 agriculture plain agri soil5-48a Sidi Saidane 36 2.73 10 12.97 agriculture plain agri soil5-49a Dar Bel Ouaer 36 3.53 10 20.11 agriculture plain agri soil5-49b Enfida 36 7.27 10 21.37 landfill plain bed of river5-49c Dhahaibia ex Bounawara 36 5.38 10 17.12 agriculture plain urban5-50a Sebknat Halg Al Manzil 36 4.02 10 24.03 none salt lake lake sediment


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Table 2(1): Result of chemical analysis using aqua regia extraction (B – Ga)

Element B Na Mg Al P S K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn GaUnit ppm % % % % % % % ppm % ppm ppm ppm % ppm ppm ppm ppm ppmDetec.Limit 1 0.001 0.01 0.01 0.001 0.01 0.01 0.01 0.1 0.001 2 0.5 1 0.01 0.1 0.1 0.01 0.1 0.15-01a 10 0.012 0.39 1.75 0.043 0.01 0.38 5.64 3.3 0.012 46 44.5 434 2.53 11.4 24.2 30.09 78.0 5.65-02a 10 0.044 0.47 1.04 0.043 0.03 0.15 14.09 3.3 0.005 37 35.6 274 2.07 8.4 19.4 12.13 67.9 3.65-02b 5 0.016 0.34 1.27 0.056 0.02 0.11 18.29 4.4 0.004 42 44.9 431 2.30 12.4 23.3 22.82 66.9 3.25-02c 15 0.292 0.43 0.67 0.099 0.06 0.22 12.37 2.2 0.002 26 22.8 254 1.55 6.5 14.4 12.52 72.5 2.05-02d 3 0.007 0.17 0.21 0.092 0.02 0.05 7.66 1.0 < .001 11 8.9 139 0.70 2.1 3.4 4.64 31.1 0.65-02f 10 0.156 0.33 0.52 0.123 0.31 0.12 11.19 2.1 < .001 21 29.6 159 1.44 5.5 13.0 21.63 87.9 1.75-02g 7 0.035 0.34 0.89 0.057 0.03 0.21 17.53 1.8 0.007 28 26.3 196 1.21 6.2 13.2 11.74 45.4 3.15-02h 14 0.030 0.57 1.63 0.059 0.02 0.31 12.04 3.6 < .001 47 46.2 325 2.19 10.1 22.1 15.36 78.6 5.65-02i 16 0.085 0.57 1.68 0.066 0.03 0.35 12.73 3.6 < .001 47 45.9 347 2.19 9.8 21.3 14.96 79.2 5.55-03a 4 0.010 0.15 0.27 0.025 0.01 0.05 11.16 1.5 0.003 18 11.5 99 0.86 3.4 10.6 5.51 32.4 0.85-03b 5 0.157 0.28 0.26 0.036 0.10 0.06 10.11 1.1 0.007 14 10.9 150 0.89 3.7 6.9 6.04 30.8 0.85-06a 1 0.005 0.06 0.21 0.007 < .01 0.04 1.31 0.5 0.001 7 5.0 40 0.34 0.9 1.8 0.95 7.0 0.65-06b1 5 0.010 0.09 0.43 0.005 < .01 0.11 0.11 1.3 0.016 17 12.0 81 0.73 2.8 5.8 2.68 16.0 1.45-06b2 4 0.010 0.14 0.67 0.004 < .01 0.13 0.09 2.0 0.006 22 18.4 171 1.22 4.2 9.6 3.68 26.2 2.15-07a 3 0.005 0.06 0.17 0.008 < .01 0.04 0.27 0.4 0.005 7 4.5 68 0.27 0.8 1.7 2.82 10.8 0.65-08a 8 0.043 0.26 0.77 0.069 0.06 0.19 9.14 1.4 < .001 20 30.0 180 0.99 4.9 11.5 46.66 91.2 2.55-08b 11 0.063 0.32 1.01 0.072 0.13 0.23 10.63 3.4 < .001 30 31.7 331 1.96 9.1 19.8 22.94 96.5 3.55-09a 29 1.520 0.76 0.65 0.064 0.68 0.19 10.82 1.5 0.005 25 22.8 216 1.02 4.0 9.2 12.96 176.6 2.15-09b 19 0.056 0.53 1.83 0.050 0.75 0.44 11.37 3.0 0.020 41 45.2 259 1.96 7.8 18.0 17.42 84.1 5.75-09c 7 0.017 0.33 1.04 0.079 0.03 0.27 9.71 1.9 < .001 28 27.7 186 1.32 5.3 12.4 17.97 81.3 3.25-09d 12 0.084 0.63 1.73 0.067 0.02 0.21 18.57 3.6 0.019 50 57.6 364 1.71 9.1 21.0 12.87 53.8 5.85-09e 11 0.032 0.33 0.82 0.077 0.03 0.19 14.51 2.1 0.012 30 30.6 302 1.36 6.4 14.7 27.51 129.5 2.95-09f 16 0.023 0.29 0.82 0.188 0.08 0.26 8.99 1.2 0.007 26 24.8 190 1.09 4.6 12.6 24.48 171.8 2.65-10a 8 0.203 0.21 0.40 0.049 0.09 0.14 7.34 1.0 0.007 16 41.8 137 1.09 6.6 21.1 66.88 169.3 1.55-10b 6 0.016 0.10 0.09 0.012 0.06 0.02 5.45 0.4 0.008 7 2.8 58 0.15 0.8 1.3 2.91 16.9 0.25-10c 44 0.040 0.86 0.44 0.143 1.86 0.15 12.11 1.1 0.010 16 14.2 126 0.79 3.3 7.1 76.28 82.1 1.45-10d 12 0.015 0.33 1.15 0.041 0.03 0.32 11.16 2.0 0.009 31 26.9 144 1.29 6.0 12.9 10.09 66.3 3.75-10e 13 0.124 0.22 0.15 0.040 0.03 0.05 8.79 1.2 0.009 14 7.5 168 0.68 2.3 3.0 4.76 60.9 0.45-10f 5 0.013 0.20 0.16 0.048 0.04 0.04 9.37 1.1 0.003 17 8.7 159 0.69 2.8 4.7 5.46 53.0 0.55-10g 23 0.247 0.46 0.92 1.038 0.41 0.22 17.07 2.2 0.015 52 70.1 493 1.83 4.6 29.5 34.61 5259.3 3.15-10h 23 0.547 0.42 0.32 0.044 0.32 0.08 12.13 1.5 < .001 33 15.4 174 1.08 5.0 9.6 10.31 64.4 0.95-10i 15 0.025 0.29 0.43 0.042 0.04 0.15 11.04 1.8 0.014 21 15.4 157 1.09 3.6 7.9 6.52 34.0 1.35-11a 3 0.011 0.14 0.51 0.019 0.01 0.12 3.27 1.1 0.004 14 11.8 201 0.89 6.6 8.1 4.12 18.4 1.75-12a 6 0.012 0.27 0.99 0.026 0.03 0.21 4.49 2.0 0.002 23 22.3 221 1.52 6.5 12.5 14.86 30.5 3.35-13a 6 0.009 0.22 0.79 0.028 0.01 0.19 1.24 1.9 0.004 21 17.2 196 1.45 6.0 10.0 6.51 27.3 2.75-14a 6 0.016 0.41 1.58 0.034 0.01 0.26 1.98 2.5 0.009 35 29.5 198 1.88 6.4 13.6 8.48 32.3 4.75-16a 16 0.022 0.52 2.17 0.106 0.07 0.47 8.86 3.6 0.007 51 51.7 400 2.36 11.7 28.3 22.35 150.9 7.35-16b 15 0.055 0.54 1.52 0.106 0.08 0.47 10.30 2.6 < .001 36 38.5 315 1.68 8.0 21.4 23.90 93.5 4.75-16c 3 0.008 0.18 0.85 0.019 0.01 0.19 2.27 1.7 0.002 23 19.2 186 1.12 4.9 10.2 10.62 37.1 2.65-16d 9 0.034 0.33 0.78 0.073 0.05 0.25 11.46 2.7 0.006 19 19.3 514 1.95 11.6 19.6 26.37 117.2 2.75-17a 13 0.037 0.24 0.18 0.043 0.06 0.05 13.20 1.5 < .001 12 10.4 181 0.57 2.9 5.2 5.61 41.1 0.75-17b 4 0.034 0.14 0.12 0.040 0.09 0.03 10.54 1.2 0.001 11 7.5 151 0.49 1.8 2.7 3.21 19.1 0.45-17c 9 0.214 0.20 0.31 0.089 0.11 0.19 13.65 1.5 0.005 14 16.6 195 0.71 4.0 11.8 56.93 151.5 1.25-17d 7 0.012 0.32 1.12 0.051 0.03 0.27 7.61 2.5 0.001 27 26.5 261 1.52 6.4 13.6 12.55 137.2 3.65-17e 3 0.010 0.17 0.45 0.035 0.02 0.14 11.51 1.5 0.009 12 13.2 175 0.79 4.1 9.8 11.46 926.8 1.65-17f 14 0.076 0.35 0.81 0.041 0.08 0.21 10.33 2.0 0.003 22 22.0 211 1.17 5.1 12.9 13.55 105.3 2.55-17g 11 0.053 0.32 0.78 0.058 0.12 0.30 22.65 3.3 0.026 16 16.3 318 1.02 7.5 16.4 32.57 91.7 2.95-17h 11 0.024 0.37 1.28 0.068 0.06 0.36 11.14 4.1 < .001 26 27.1 604 1.86 11.1 28.6 37.47 84.9 4.25-17i 9 0.209 0.20 0.29 0.088 0.09 0.18 13.49 1.5 0.005 11 14.5 180 0.71 3.9 11.6 56.80 186.9 1.05-17j 11 0.032 0.52 1.87 0.080 0.01 0.31 10.40 4.5 0.012 43 45.8 393 2.44 11.2 24.6 62.05 92.7 6.05-17k 12 0.022 0.36 1.27 0.073 0.06 0.38 10.85 4.0 0.012 27 27.7 602 1.84 11.4 29.0 37.52 85.5 4.15-18a 3 0.010 0.15 0.15 0.021 0.03 0.05 6.21 0.8 0.005 7 5.0 104 0.39 1.2 2.1 2.56 15.1 0.45-18b 25 0.608 0.82 1.51 0.056 0.21 0.39 7.41 3.1 0.003 34 50.5 247 1.97 7.7 16.2 12.41 62.1 4.55-18c 4 0.015 0.25 0.67 0.052 0.03 0.19 13.76 2.0 0.012 19 18.3 293 1.58 7.1 16.3 26.27 42.5 2.15-18d1 9 0.022 0.46 1.30 0.063 0.07 0.23 18.66 2.0 0.008 32 30.4 233 1.31 6.2 17.3 12.47 33.3 3.75-18e 7 0.133 0.28 0.35 0.038 0.09 0.15 4.05 0.9 < .001 13 10.7 86 0.52 2.3 5.1 8.02 25.6 1.15-19a 7 0.020 0.24 0.71 0.042 0.02 0.22 11.76 1.7 0.007 21 19.8 146 0.86 4.2 10.1 8.58 40.7 2.45-20a 4 0.007 0.15 0.80 0.012 0.01 0.18 2.91 1.7 0.008 22 16.8 122 1.07 3.8 9.3 3.72 18.0 2.35-21a 7 0.038 0.31 1.01 0.038 0.08 0.30 12.93 1.8 < .001 25 20.6 143 1.13 5.5 11.2 5.82 21.1 3.35-22a 3 0.012 0.14 0.38 0.017 0.01 0.10 4.87 0.8 0.002 12 8.9 51 0.42 1.8 3.9 2.17 7.3 1.15-23a 8 0.039 0.35 1.18 0.039 0.39 0.37 19.44 2.9 < .001 23 28.2 343 2.01 9.0 20.9 24.49 107.6 4.25-24a 9 0.016 0.36 0.74 0.171 0.06 0.30 16.83 1.2 0.007 19 21.1 203 1.05 4.3 11.1 15.62 88.1 2.15-25a 7 0.011 0.69 1.45 0.037 0.05 0.28 13.64 2.4 0.012 31 28.1 351 1.81 9.7 20.3 14.16 38.8 4.45-26a 6 0.041 0.19 0.36 0.065 0.11 0.11 8.38 1.0 0.006 12 19.7 115 0.78 3.2 10.6 51.47 96.9 1.35-26b 5 0.015 0.58 1.58 0.071 0.04 0.19 16.79 3.1 0.010 43 41.9 346 2.31 9.5 22.2 25.03 82.4 4.85-26c 3 0.021 0.43 0.96 0.084 0.04 0.19 21.96 2.1 0.010 36 30.8 223 1.88 6.4 17.4 12.37 91.5 2.65-27a 7 0.015 0.28 0.90 0.048 0.01 0.19 6.20 2.0 < .001 27 24.6 224 1.87 7.6 15.1 13.30 71.4 2.95-28a 3 0.003 0.13 0.65 0.012 0.01 0.14 0.37 1.2 < .001 18 14.3 306 0.91 5.1 6.4 6.91 35.2 2.15-29a 5 0.027 0.12 0.36 0.038 < .01 0.12 8.07 0.6 < .001 12 9.4 68 0.41 1.9 3.6 6.42 20.4 1.25-31a 7 0.017 0.37 1.00 0.074 0.03 0.32 20.09 1.7 < .001 26 25.7 229 1.24 7.2 15.3 13.77 42.6 3.65-32a 4 0.003 0.14 0.67 0.017 < .01 0.17 0.82 1.1 < .001 15 13.5 143 0.88 3.4 6.9 6.96 27.1 2.15-33a 5 0.011 0.16 0.63 0.023 0.04 0.17 0.72 1.5 < .001 16 14.2 304 1.51 7.7 9.8 8.60 38.7 2.35-34a 219 0.023 0.08 0.10 0.073 0.75 0.05 5.71 1.0 0.002 3 56.4 28 0.39 1.2 3.4 60.50 24473.0 2.35-34b 13 0.032 0.28 0.88 0.030 0.07 0.18 2.36 2.3 < .001 21 24.5 227 1.86 9.0 14.3 8.24 66.7 3.25-35a 3 0.011 0.14 0.30 0.024 0.01 0.10 4.96 0.5 0.006 9 8.8 167 0.45 1.5 3.7 29.70 46.7 0.85-36a 4 0.008 0.14 0.24 0.023 0.01 0.10 2.20 0.5 < .001 9 6.6 61 0.58 1.6 3.4 10.82 24.8 0.7


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Table 2(2): Result of chemical analysis using aqua regia extraction (As – U)

Element As Se Sr Mo Ag Cd Sb Te Ba La W Au Hg Tl Pb Bi Th UUnit ppm ppm ppm ppm ppb ppm ppm ppm ppm ppm ppm ppb ppb ppm ppm ppm ppm ppmDetec.Limit 0.1 0.1 0.5 0.01 2 0.01 0.02 0.02 0.5 0.5 0.2 0.2 5 0.02 0.01 0.02 0.1 0.15-01a 11.5 0.2 86.9 0.65 61 0.25 0.49 0.02 125.0 13.1 < .2 1.6 72 0.15 36.26 0.18 3.1 0.35-02a 8.7 0.2 580.9 0.82 70 0.26 0.62 0.07 136.2 8.8 < .2 0.5 28 0.07 19.08 0.12 2.9 0.85-02b 1.7 0.1 623.8 0.47 30 0.14 0.15 0.06 353.0 9.1 < .2 0.8 31 0.05 16.95 0.10 3.8 0.95-02c 5.9 0.2 536.4 0.55 118 0.25 0.59 0.06 146.0 6.5 < .2 2.5 26 0.05 24.52 0.09 1.5 0.45-02d 4.5 0.1 221.8 0.26 63 0.20 0.24 0.03 22.4 4.7 < .2 1.3 26 0.02 15.23 0.15 0.6 0.45-02f 5.2 0.4 507.3 0.94 1742 0.25 0.75 0.05 388.0 5.6 < .2 68.4 102 0.05 30.32 0.16 1.4 0.85-02g 5.5 0.1 253.3 0.37 103 0.23 0.42 < .02 74.6 7.3 < .2 3.4 29 0.07 21.69 0.35 1.2 0.45-02h 8.5 < .1 411.7 0.55 199 0.32 0.49 0.04 106.5 11.2 < .2 5.1 33 0.12 24.91 0.15 3.0 0.65-02i 7.6 < .1 361.3 0.66 158 0.26 0.42 0.05 125.3 11.3 < .2 8.1 40 0.12 23.73 0.15 2.9 0.65-03a 7.3 0.1 157.5 0.35 32 0.13 0.39 < .02 39.1 5.9 < .2 2.2 20 0.02 28.17 0.04 1.3 0.35-03b 6.0 0.2 233 0.47 15 0.13 0.54 0.04 85.8 4.0 < .2 1.3 30 0.02 20.38 0.04 0.7 0.35-06a 2.4 0.1 37.1 0.08 9 0.03 0.08 < .02 6.8 1.9 < .2 0.3 6 < .02 3.21 0.02 0.4 < .15-06b1 6.0 < .1 15.4 0.27 9 0.04 0.22 < .02 32.1 6.0 < .2 0.2 10 0.04 10.35 0.04 1.8 0.15-06b2 8.6 < .1 8.7 0.54 16 0.05 0.32 < .02 30.0 6.1 < .2 0.5 8 0.06 8.19 0.06 2.1 0.15-07a 2.7 < .1 10.8 0.10 8 0.04 0.07 < .02 14.6 2.1 < .2 < .2 8 0.02 5.53 0.02 0.4 < .15-08a 4.5 0.2 238.8 0.38 181 0.31 0.96 0.02 116.7 6.7 < .2 20.1 164 0.05 53.29 0.08 1.3 0.55-08b 6.5 0.3 296.2 0.63 75 0.27 0.35 0.03 167.1 7.7 < .2 1.8 63 0.10 44.66 0.16 2.4 0.55-09a 21.2 0.2 490.4 0.50 258 2.63 3.34 0.05 160.5 5.9 < .2 5.0 418 0.43 477.53 0.25 1.4 0.45-09b 5.6 0.2 638.7 0.81 69 0.23 0.50 0.04 131.6 10.1 < .2 2.0 50 0.12 45.86 0.19 3.6 1.15-09c 8.3 < .1 250.5 0.40 375 0.26 0.59 0.03 142.7 7.8 < .2 22.1 174 0.09 50.88 0.64 1.6 0.35-09d 1.5 0.3 660.7 0.60 29 0.28 0.10 0.06 328.0 12.5 < .2 1.8 14 0.06 9.49 0.11 4.3 1.35-09e 4.0 0.1 459.5 0.69 243 0.31 0.88 0.06 241.7 8.3 < .2 24.9 331 0.06 62.39 0.13 1.5 0.45-09f 6.3 0.5 183.6 0.71 196 0.66 1.24 0.03 131.3 7.0 < .2 13.5 199 0.11 169.11 0.28 0.9 0.35-10a 4.0 0.3 199 6.42 50 0.31 1.51 0.02 162.7 5.1 2.2 4.8 89 0.05 151.70 0.11 1.3 0.55-10b 2.9 < .1 181.1 0.20 14 0.09 0.16 0.04 20.3 1.6 < .2 0.2 9 < .02 15.08 < .02 0.2 0.45-10c 7.7 0.7 625 4.45 1017 0.21 0.63 0.02 48.9 4.5 < .2 62.6 259 0.09 205.08 0.22 0.9 1.05-10d 5.8 < .1 274.9 0.39 44 0.21 0.32 0.03 327.3 9.1 < .2 2.6 46 0.11 31.92 0.12 2.0 0.35-10e 11.8 0.3 253 0.28 29 0.23 0.43 0.03 46.9 4.1 < .2 1.0 18 0.04 37.76 0.04 0.4 0.35-10f 11.4 0.1 316.1 0.35 61 0.27 0.50 0.04 42.4 4.2 < .2 0.7 41 0.04 38.97 0.03 0.5 0.35-10g 16.6 3.8 673.4 4.16 462 11.16 1.59 0.05 508.9 22.9 < .2 6.5 144 1.24 875.07 0.07 1.9 12.35-10h 13.7 0.1 515.1 2.56 43 0.19 0.54 0.04 39.1 4.7 < .2 1.4 86 0.05 28.88 0.07 0.9 1.25-10i 5.6 0.4 411.8 0.51 43 0.15 0.45 0.05 81.1 5.5 < .2 1.3 16 0.04 19.02 0.06 1.0 0.55-11a 3.4 < .1 42.4 0.25 13 0.09 0.14 < .02 35.6 5.1 < .2 0.5 18 0.06 9.02 0.06 1.8 0.45-12a 3.5 0.3 60.3 0.23 15 0.09 0.10 < .02 101.1 7.3 < .2 0.9 < 5 0.06 9.35 0.09 2.5 0.35-13a 3.6 0.1 64.7 0.24 20 0.08 0.11 < .02 39.0 8.1 < .2 0.7 8 0.06 8.88 0.07 2.6 0.45-14a 4.5 0.1 73.9 0.28 26 0.11 0.13 < .02 48.9 7.7 < .2 0.4 10 0.08 9.55 0.09 2.5 0.25-16a 12.9 0.5 194.5 0.72 280 1.02 1.32 0.03 239.4 16.8 < .2 7.0 442 0.33 214.84 0.26 2.8 0.45-16b 4.0 0.3 211.2 0.37 113 0.50 0.49 0.02 148.2 11.1 < .2 3.5 262 0.11 48.29 0.17 2.1 0.35-16c 2.6 0.2 45 0.25 26 0.11 0.18 < .02 79.3 7.3 < .2 1.2 27 0.07 16.38 0.07 1.8 0.15-16d 4.5 0.2 185.1 0.57 60 0.46 0.57 0.02 194.4 7.2 < .2 5.4 237 0.13 84.52 0.21 2.2 0.35-17a 11.4 0.5 605.4 0.31 45 0.24 0.32 0.03 60.5 5.5 < .2 2.5 19 0.04 20.52 0.04 1.5 0.35-17b 7.4 0.1 332.4 0.31 111 0.14 0.12 0.02 29.6 4.2 < .2 11.3 45 0.04 8.50 0.02 0.5 0.25-17c 31.4 0.5 410 0.63 69 0.56 3.51 0.08 207.8 5.7 < .2 28.8 62 0.10 79.99 0.14 0.7 0.45-17d 2.3 0.1 180.2 0.30 62 0.62 0.19 < .02 114.7 8.1 < .2 1.3 67 0.07 48.38 0.09 1.9 0.25-17e 3.6 0.3 196.5 0.26 30 4.99 0.29 0.02 131.7 4.4 < .2 2.8 29 0.10 211.79 0.07 1.0 0.25-17f 5.7 0.1 255.1 0.40 52 0.31 0.73 < .02 171.0 6.1 < .2 3.5 105 0.06 36.78 0.09 1.5 0.45-17g 81.4 0.7 466.9 0.58 75 0.30 8.32 0.10 251.2 12.6 < .2 3.9 71 0.35 78.06 0.19 1.6 0.55-17h 57.2 0.3 135.3 0.53 112 0.38 3.70 0.06 225.8 12.2 < .2 6.2 95 0.27 55.09 0.27 1.7 0.35-17i 28.8 0.2 375.1 0.56 94 0.48 3.70 0.05 209.8 5.5 < .2 28.5 68 0.09 92.84 0.15 0.7 0.45-17j 4.0 0.6 308.3 0.40 85 0.27 0.11 0.04 161.1 12.0 < .2 0.7 21 0.11 40.04 0.16 3.7 0.65-17k 55.0 0.5 133.3 0.56 117 0.34 3.62 0.08 220.0 12.1 < .2 6.0 90 0.26 53.52 0.27 1.8 0.35-18a 3.0 < .1 153.9 0.17 12 0.07 0.08 0.02 24.7 2.5 < .2 < .2 11 < .02 4.59 0.02 0.3 0.15-18b 4.8 0.5 180.3 0.39 47 0.15 0.14 < .02 111.0 8.8 < .2 1.5 26 0.09 21.63 0.11 3.0 0.55-18c 3.0 0.3 319.5 0.47 61 0.17 0.23 0.04 170.7 6.4 < .2 2.7 35 0.05 15.30 0.13 1.1 0.25-18d1 4.0 0.6 241.6 0.38 51 0.24 0.30 0.03 192.6 10.5 < .2 1.5 44 0.11 22.16 0.12 1.4 0.35-18e 2.5 0.1 105.7 0.20 22 0.13 0.17 < .02 69.7 3.7 < .2 0.9 10 0.03 12.48 0.05 0.8 0.25-19a 7.9 0.4 320.9 0.21 28 0.17 0.21 0.03 103.9 7.1 < .2 0.9 38 0.07 17.97 0.06 1.2 0.35-20a 4.0 0.3 28.7 0.23 16 0.04 0.13 < .02 35.1 7.8 < .2 0.2 28 0.06 7.39 0.06 1.9 0.15-21a 4.0 0.3 216.1 0.26 22 0.11 0.16 < .02 76.3 8.6 < .2 0.8 19 0.09 9.88 0.10 1.5 0.35-22a 3.7 0.2 109.1 0.13 8 0.04 0.12 0.02 19.5 4.1 < .2 0.2 6 0.04 5.39 0.03 0.8 0.35-23a 111.7 0.6 563.8 0.79 50 0.19 3.16 0.08 114.2 7.2 < .2 2.2 1296 0.77 34.72 0.16 1.7 0.35-24a 1.9 0.3 328.9 0.37 84 0.21 0.26 0.04 157.5 6.7 < .2 3.0 52 0.05 26.36 0.08 0.8 0.35-25a 6.4 0.3 133.8 0.82 28 0.19 0.26 0.02 118.7 7.5 < .2 1.0 19 0.11 23.01 0.15 1.5 0.25-26a 3.5 0.5 247.7 0.73 105 0.25 20.83 0.02 184.2 4.4 < .2 11.9 48 0.03 1807.50 0.19 0.8 0.35-26b 3.9 0.5 515.1 0.60 48 0.24 0.15 0.05 489.1 10.3 < .2 0.4 25 0.09 14.32 0.12 2.6 0.55-26c 7.2 0.8 471.9 0.86 42 0.39 0.34 0.05 299.6 7.8 < .2 1.4 21 0.07 21.38 0.09 1.6 0.55-27a 4.8 0.8 183.8 0.57 48 0.26 0.21 0.03 115.1 7.3 < .2 0.6 19 0.07 23.67 0.10 2.5 0.45-28a 2.9 0.1 49 0.20 30 0.10 0.12 < .02 134.8 8.9 < .2 < .2 82 0.07 14.17 0.07 2.4 0.25-29a 3.8 0.2 886.2 0.13 42 0.09 0.16 0.08 28.5 4.5 0.4 3.0 21 0.04 13.71 0.05 0.5 0.55-31a 4.9 0.3 232.5 0.37 53 0.21 0.25 0.05 102.3 8.1 < .2 1.8 108 0.09 18.00 0.09 1.5 0.35-32a 3.3 < .1 19.5 0.19 23 0.08 0.15 < .02 53.3 4.6 < .2 < .2 21 0.07 10.54 0.05 1.2 0.15-33a 5.2 0.1 48.5 0.38 34 0.11 0.13 < .02 68.6 5.5 < .2 0.6 41 0.08 18.65 0.07 2.4 0.25-34a 25.8 0.1 3245 0.63 2331 66.86 21.58 0.26 94.3 < .5 < .2 < .2 1890 0.40 4681.34 < .02 0.2 0.15-34b 3.7 0.5 167.7 0.56 17 0.13 0.09 0.02 64.4 9.2 < .2 < .2 19 0.07 15.93 0.09 4.0 0.55-35a 1.9 0.1 131.8 0.30 60 0.12 0.35 < .02 59.4 2.9 < .2 2.2 28 0.02 34.76 0.02 0.5 0.25-36a 2.7 0.1 56.7 0.26 175 0.06 0.34 < .02 22.6 2.9 < .2 2.7 29 0.02 68.48 0.04 0.7 0.2


60

Table 2(1) (continued): Result of chemical analysis using aqua regia extraction (B – Ga)

Table 2(2) (continued): Result of chemical analysis using aqua regia extraction (As – U)

Element As Se Sr Mo Ag Cd Sb Te Ba La W Au Hg Tl Pb Bi Th UUnit ppm ppm ppm ppm ppb ppm ppm ppm ppm ppm ppm ppb ppb ppm ppm ppm ppm ppmDetec.Limit 0.1 0.1 0.5 0.01 2 0.01 0.02 0.02 0.5 0.5 0.2 0.2 5 0.02 0.01 0.02 0.1 0.15-37a 6.2 0.3 210.2 0.43 55 0.15 0.30 0.04 102.6 9.9 < .2 5.5 51 0.12 22.52 0.10 2.2 0.85-38a 4.9 0.6 584.4 1.19 50 0.32 0.17 0.07 112.8 9.7 < .2 < .2 27 0.11 20.17 0.15 4.8 0.85-39a 3.3 0.3 53.2 0.47 13 0.09 0.16 0.02 248.7 5.2 < .2 0.5 18 0.08 10.64 0.06 1.6 0.15-39c 17.8 0.2 4583 0.35 1664 35.61 14.52 0.41 230.6 0.7 < .2 < .2 1056 0.12 3421.79 0.02 0.1 0.15-40a 2.8 0.2 48.9 0.29 19 0.09 0.09 0.02 84.3 7.4 < .2 < .2 19 0.08 10.32 0.07 1.6 0.15-41a 3.5 0.3 277.4 0.52 46 0.20 0.12 0.04 155.4 10.0 < .2 0.5 37 0.11 14.83 0.11 3.3 0.55-42a 3.0 0.3 141.8 0.41 42 0.14 0.14 0.02 106.0 7.4 < .2 0.4 22 0.07 14.59 0.09 2.0 0.35-43a 2.1 0.2 33.6 0.28 17 0.10 0.09 < .02 53.4 7.6 < .2 < .2 13 0.08 6.97 0.07 2.3 0.25-44a 3.5 0.2 127.3 0.43 16 0.11 0.09 0.02 62.5 6.9 < .2 0.3 14 0.11 7.61 0.10 3.3 0.65-46b 3.4 0.1 125.1 0.29 30 0.15 0.12 < .02 99.8 10.4 < .2 0.8 18 0.09 14.66 0.08 2.2 0.45-47a 2.8 < .1 34.8 0.23 15 0.06 0.08 < .02 36.3 6.5 < .2 0.5 22 0.07 6.09 0.06 1.9 0.25-48a 3.8 0.3 227.4 0.45 32 0.19 0.15 0.05 164.5 11.5 < .2 0.6 19 0.11 11.91 0.11 2.1 0.45-49a 4.4 0.5 219.4 0.73 42 0.22 0.10 0.04 113.2 12.3 < .2 0.5 21 0.12 19.62 0.16 5.2 0.85-49b 2.3 0.3 109.3 0.33 16 0.09 0.06 0.02 44.8 7.7 < .2 < .2 12 0.06 6.03 0.06 2.5 0.45-49c 1.5 < .1 87.9 0.12 10 0.03 0.06 < .02 18.6 4.5 < .2 < .2 7 0.02 3.03 0.02 1.3 0.35-50a 2.4 0.3 129.1 0.41 26 0.11 0.13 0.02 66.7 7.0 < .2 0.8 10 0.06 13.47 0.07 2.0 0.3

Element B Na Mg Al P S K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn GaUnit ppm % % % % % % % ppm % ppm ppm ppm % ppm ppm ppm ppm ppmDetec.Limit 1 0.001 0.01 0.01 0.001 0.01 0.01 0.01 0.1 0.001 2 0.5 1 0.01 0.1 0.1 0.01 0.1 0.15-37a 23 0.026 1.46 1.45 0.041 0.03 0.44 7.61 2.1 < .001 32 29.3 288 1.56 6.5 14.0 11.20 54.2 4.65-38a 10 0.021 0.49 1.74 0.078 0.02 0.23 11.26 4.0 < .001 40 48.9 415 3.29 13.9 23.7 13.05 107.1 5.25-39a 5 0.005 0.18 0.82 0.016 0.02 0.17 5.10 1.4 < .001 21 18.7 298 1.31 5.1 10.7 5.46 32.9 2.75-39c 65 0.016 0.06 0.12 0.106 0.30 0.07 7.92 0.7 < .001 5 66.4 44 0.31 1.3 2.5 34.24 12101.7 1.45-40a 5 0.007 0.23 1.02 0.021 0.02 0.20 3.66 1.6 0.006 24 21.0 184 1.16 4.7 10.0 6.67 38.7 3.05-41a 12 0.055 0.46 1.65 0.044 0.07 0.29 10.13 3.0 0.001 36 38.3 301 2.03 9.1 18.1 13.14 65.4 5.35-42a 8 0.017 0.29 0.91 0.029 0.03 0.20 5.63 1.8 < .001 23 21.3 231 1.37 5.5 10.8 13.04 45.0 3.05-43a 6 0.007 0.26 0.98 0.019 0.04 0.20 1.16 1.8 0.004 22 21.1 220 1.29 6.5 11.3 7.16 27.8 3.45-44a 10 0.009 0.32 1.54 0.020 1.44 0.27 6.04 2.5 < .001 32 32.8 212 1.84 7.3 12.9 7.93 39.1 5.05-46b 9 0.019 0.34 1.04 0.040 0.03 0.25 3.78 1.7 0.009 27 22.0 250 1.36 6.5 10.8 10.32 33.7 3.55-47a 5 0.004 0.24 0.87 0.017 0.01 0.19 1.38 1.5 < .001 21 18.6 163 1.08 4.7 8.5 6.21 23.3 2.95-48a 8 0.016 0.38 1.17 0.047 0.03 0.32 13.31 2.1 < .001 32 31.4 267 1.44 6.6 15.5 12.79 40.9 4.25-49a 11 0.031 0.56 1.62 0.050 0.05 0.27 6.33 3.5 0.002 35 39.0 361 2.72 11.3 19.3 12.65 84.9 5.25-49b 5 0.008 0.25 0.73 0.023 0.02 0.17 3.17 1.6 0.001 20 17.2 210 1.26 5.7 8.4 5.61 29.2 2.45-49c 3 0.006 0.12 0.30 0.016 0.01 0.09 2.98 0.6 < .001 10 6.7 78 0.46 2.3 3.8 3.35 12.7 1.05-50a 21 0.120 0.46 0.88 0.037 0.06 0.21 4.43 1.6 0.006 23 20.5 191 1.28 5.4 9.9 8.41 37.7 2.8


61

Figure 3: Box & Whisker Plot of element concentration for natural sediments, natural soils, agricultural soils,

urban soils, waste-related soils, and all types.

±Std. Dev.±Std. Err.Mean

Box & Whisker Plot (EGMAP2001: Carte#5 Tounis, Sediment data)

Element

Con

cent

ratio

n in

sed

imen

t (m

g/kg

)

0.01

0.10

1.00

10.00

100.00

1000.00

10000.00

100000.00

BNa

MgAl

PS

KCa

ScTi

VCr

MnFe

CoNi

CuZn

GaAs

SeSr

MoAg

CdSb

TeBa

LaAu

HgTl

PbBi

ThU


Box & Whisker Plot (EFMAP2001: Carte#5 Tounis, Natural Soil)

Element

Con

cent

ratio

n in

soi

l (m

g/kg

)

0.01

0.10

1.00

10.00

100.00

1000.00

10000.00

100000.00

BNa

MgAl

PS

KCa

ScTi

VCr

MnFe

CoNi

CuZn

GaAs

SeSr

MoAg

CdSb

TeBa

LaAu

HgTl

PbBi

ThU


Box & Whisker Plot (EGMAP2001: Carte#5 Tounis, Agricultural Soil)

Element

Con

cent

ratio

n in

soi

l (m

g/kg

)

0.01

0.10

1.00

10.00

100.00

1000.00

10000.00

100000.00

BNa

MgAl

PS

KCa

ScTi

VCr

MnFe

CoNi

CuZn

GaAs

SeSr

MoAg

CdSb

TeBa

LaAu

HgTl

PbBi

ThU


Box & Whisker Plot (EGMAP2001: Carte#5 Tounis, Urban soil)

Element

Con

cent

ratio

n in

soi

l (m

g/kg

)

0.01

0.10

1.00

10.00

100.00

1000.00

10000.00

100000.00

BNa

MgAl

PS

KCa

ScTi

VCr

MnFe

CoNi

CuZn

GaAs

SeSr

MoAg

CdSb

TeBa

LaAu

HgTl

PbBi

ThU


Box & Whisker Plot (EGMAP2001: Carte#5 Tounis, Landfill soil)

Element

Con

cent

ratio

n in

soi

l (m

g/kg

)

0.01

0.10

1.00

10.00

100.00

1000.00

10000.00

100000.00

BNa

MgAl

PS

KCa

ScTi

VCr

MnFe

CoNi

CuZn

GaAs

SeSr

MoAg

CdSb

TeBa

LaAu

HgTl

PbBi

ThU

Waste-related

Urban soil Agricultural soil

Natural soil Natural sediment


Box & Whisker Plot (EGMAP2001: Carte#5 Tounis: All data)

Element

Con

cent

ratio

n in

soi

l/sed

imen

t (m

g/kg

)

0.01

0.10

1.00

10.00

100.00

1000.00

10000.00

100000.00

BNa

MgAl

PS

KCa

ScTi

VCr

MnFe

CoNi

CuZn

GaAs

SeSr

MoAg

CdSb

TeBa

LaAu

HgTl

PbBi

ThU

All types


62

Figure 4(1): Bivariate (soil/sediment type and concentrations level) histogram for Ag, Au, Al, As, B, and Ba.

Bivariate Histogram (EGMAP2001: Carte#5 Tounis)




Bivariate Histogram (EGMAP:Carte#5 Tunis) Bivariate Histogram (EGMAP2001: Carte#5 Tounis)


63

Figure 4(2): Bivariate (soil/sediment type and concentration level) histograms for Bi, Ca, Cd, Cr, Co, and Cu.

Bivariate Histogram (EGMAP2001: Carte#5 Tounis) Bivariate Histogram (EGMAP2001: Carte#5 Tounis)

Bivariate Histogram (EGMAP2001: Carte#5 Tounis)Bivariate Histogram (EGMAP2001: Carte#5 Tounis)




64

Figure 4(3): Bivariate (soil/sediment type and concentration level) histograms for Fe, Ga, Hg, K, La, and Mg.


Bivariate Histogram (EGMAP2001: Carte#5 Tounis)Bivariate Histogram (EGMAP2001: Carte#5 Tounis)

Bivariate Histogram (EGMAP2001: Carte#5 Tounis)Bivariate Histogram (EGMAP: Carte#5 Tunis)


65

Figure 4(4): Bivariate (soil/sediment type and concentration level) histograms for Mn, Mo, Na, Ni, P, and Pb.


Bivariate Histogram (EGMAP: Carte#5 Tunis) Bivariate Histogram (EGMAP2001: Carte#5 Tounis)



66

Figure 4(5): Bivariate (soil/sediment type and concentration level) histograms for S, Sb, Sc, Se, Sr, and Te.

Bivariate Histogram (CARTE5-3.STA 41v*147c) Bivariate Histogram (EGMAP2001: Carte#5 Tounis)

Bivariate Histogram (EGMAP2001: Carte#5 Tounis) Bivariate Histogram (CARTE5-3.STA 41v*147c)



67

Figure 4(6): Bivariate (soil/sediment type and concentration level) histograms for Th, Tl, U, V, and Zn.





68

Location of Major Cities

TunisGrombalia

Hammamet

Zaghouan

M.Temim

Enfida

Figure 5(1): Index map for the 3D surface plot diagram Figures 5(2)-5(14) and Figure 6. Closed squares are the locations of major cities, and solid line is shown the Mediterranean shoreline.

N

50km


69

3.835 7.671 11.506 15.341 19.176 23.012 26.847 30.682 34.517 38.353 above

3D Surface Plot (As contamination CARTE5)Distance Weighted Least Squares

Figure 5(2): 3D surface plot for As (mg/kg) concentration in surface soil/sediment. The open circles are raw data and the curved surface is statistically smoothed (distance weighted least squares) distribution. The background value of As concentration is <7.7 mg/kg. A strong anomaly could be observed in the agricultural zone between Tunis and Zaghouan.


70

3.314 6.629 9.943 13.257 16.571 19.886 23.200 26.514 29.829 33.143 above

3D Surface Plot (B contamination CARTE5)Distance Weighted Least Squares

Figure 5(3): 3D surface plot for B (mg/kg) concentration in surface soil/sediment. The open circles are raw data and the curved surface is statistically smoothed (distance weighted least squares) distribution. The background value of B concentration is <6.6 mg/kg. Strong anomalies could be observed in the agricultural zone between Hammamet and Zaghouan, and around the Lake Tunis to Carthage.


71

0.073 0.147 0.220 0.294 0.367 0.441 0.514 0.587 0.661 0.734 above

3D Surface Plot (Cd contamination CARTE5)Distance Weighted Least Squares

Figure 5(4): 3D surface plot for Cd (mg/kg) concentration in surface soil/sediment. The open circles are raw data and the curved surface is statistically smoothed (distance weighted least squares) distribution. The background value of Cd concentration is <0.15 mg/kg. A strong anomaly could be observed in the Tunis urban zone and it southern to southestern agricultural zone.


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1.217 2.434 3.652 4.869 6.086 7.303 8.520 9.737 10.955 12.172 above

3D Surface Plot (Co contamination CARTE5)Distance Weighted Least Squares

Figure 5(5): 3D surface plot for Co (mg/kg) concentration in surface soil/sediment. The open circles are raw data and the curved surface is statistically smoothed (distance weighted least squares) distribution. The background value of Co concentration is <6.1 mg/kg. A strong anomaly could be observed from Tunis urban zone to the agricultural zone between Tunis and Zaghouan.


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7.131 12.099 17.068 22.037 27.006 31.975 36.944 41.912 46.881 51.850 above

3D Surface Plot (Cr contamination CARTE5)Distance Weighted Least Squares

Figure 5(6): 3D surface plot for Cr (mg/kg) concentration in surface soil/sediment. The open circles are raw data and the curved surface is statistically smoothed (distance weighted least squares) distribution. The background value of Cr concentration is <17.1 mg/kg. A strong anomaly could be observed in the Tunis urban zone and in the agricultural zone between Tunis and Zaghouan


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4.389 9.398 14.407 19.416 24.425 29.434 34.442 39.451 44.460 49.469 above

3D Surface Plot (Cu contamination CARTE5)Distance Weighted Least Squares

Figure 5(7): 3D surface plot for Cu (mg/kg) concentration in surface soil/sediment. The open circles are raw data and the curved surface is statistically smoothed (distance weighted least squares) distribution. The background value of Cu concentration is <19.4 mg/kg. A strong anomaly could be observed in the Tunis urban zone especially around the Tunis Lake.


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0.055 0.109 0.164 0.218 0.273 0.327 0.382 0.437 0.491 0.546 above

3D Surface Plot (Hg contamination CARTE5)Distance Weighted Least Squares

Figure 5(8): 3D surface plot for Hg (mg/kg) concentration in surface soil/sediment. The open circles are raw data and the curved surface is statistically smoothed (distance weighted least squares) distribution. The background value of Hg concentration is <0.055 mg/kg. A strong anomaly could be observed in the agricultural zone near Zaghouan and northward. The anomalous zone extend eastward (around hammam Zriba).


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0.185 0.369 0.554 0.739 0.923 1.108 1.293 1.477 1.662 1.847 above

3D Surface Plot (Mo contamination CARTE5)Distance Weighted Least Squares

Figure 5(9): 3D surface plot for Mo (mg/kg) concentration in surface soil/sediment. The open circles are raw data and the curved surface is statistically smoothed (distance weighted least squares) distribution. The background value of Mo concentration is <0.55 mg/kg. A strong anomaly could be observed in the industrial zone of Rades, Tunis urban zone.


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3.982 6.342 8.701 11.061 13.421 15.780 18.140 20.499 22.859 25.218 above

3D Surface Plot (Ni contamination CARTE5)Distance Weighted Least Squares

Figure 5(10): 3D surface plot for Ni (mg/kg) concentration in surface soil/sediment. The open circles are raw data and the curved surface is statistically smoothed (distance weighted least squares) distribution. The background value of Ni concentration is <11.1 mg/kg. A strong anomaly could be observed from Tunis urban zone to the agricultural zone between Tunis and Zaghouan


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8.967 17.935 26.902 35.869 44.837 53.804 62.771 71.738 80.706 89.673 above

3D Surface Plot (Pb contamination CARTE5)Distance Weighted Least Squares

Figure 5(11): 3D surface plot for Pb (mg/kg) concentration in surface soil/sediment. The open circles are raw data and the curved surface is statistically smoothed (distance weighted least squares) distribution. The background value of Pb concentration is <17.9 mg/kg. A strong anomaly could be observed in the Tunis urban zone.


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0.209 0.418 0.627 0.835 1.044 1.253 1.462 1.671 1.880 2.088 above

3D Surface Plot (Sb contamination CARTE5)Distance Weighted Least Squares

Figure 5(12): 3D surface plot for Sb (mg/kg) concentration in surface soil/sediment. The open circles are raw data and the curved surface is statistically smoothed (distance weighted least squares) distribution. The background value of Sb concentration is <0.4 mg/kg. A strong anomaly could be observed in the agricultural zone between Grombalia and Nabeul.


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0.058 0.117 0.175 0.234 0.292 0.350 0.409 0.467 0.525 0.584 above

3D Surface Plot (Se contamination CARTE5)Distance Weighted Least Squares

Figure 5(13): 3D surface plot for Se (mg/kg) concentration in surface soil/sediment. The open circles are raw data and the curved surface is statistically smoothed (distance weighted least squares) distribution. The background value of Se concentration is <0.12 mg/kg. A strong anomaly could be observed in the coastal zone from the Lake Tunis to Hammam-Lif.


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13.179 26.358 39.538 52.717 65.896 79.075 92.254 105.434 118.613 131.792 above

3D Surface Plot (Zn contamination CARTE5)Distance Weighted Least Squares

Figure 5(14): 3D surface plot for Zn (mg/kg) concentration in surface soil/sediment. The open circles are raw data and the curved surface is statistically smoothed (distance weighted least squares) distribution. The background value of Zn concentration is <26.4 mg/kg. A strong anomaly could be observed in the Tunis urban zone and surrounding agricultural zone.


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0.064 0.127 0.191 0.254 0.318 0.381 0.445 0.509 0.572 0.636 above

3D Surface Plot (Magnetic Susceptibility Variation CARTE5)Distance Weighted Least Squares

Figure 6: 3D surface plot for magnetic susceptibility of surface soil/sediment. The open circles are raw data and the curved surface is statistically smoothed (distance weighted least squares) distribution. The background value is <0.38 x 10-3 (SI). A strong anomaly could be observed in the Tunis urban zone and its surroundings, of which distribution pattern can be correlated with the general trend of PTEs contamination anomalies.


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Table 3: Several criteria for environmental screening of soil/sediment contamination (unit: mg/kg except specified).

NOAA SquiRTs for Freshwater Sediment* Netherlands** Japan PTEs Background LTEL TEL PEL UET Ref

. Interv. Test EQS soil

Al 0.26% 2.55% Sb 0.16 3 As 1.1 10.798 5.9 17 17 29 50 30 50 Ba 0.7 200 2000 400 Cd 0.1-0.3 0.583 0.596 3.53 3 0.8 12 5 9 Cr 7-13 36.286 37.3 90 95 100 380 250 Co 10 10 300 50 Cu 10-25 28.012 35.7 197 86 36 190 100 Fe 0.99-1.8% 18.84% Pb 4-17 37 35 91.3 127 85 530 150 600 Mn 400 630 1100 Mo 10 10 200 40 Hg 0.004-0.051 0.174 0.486 0.56 0.3 10 2 3 Ni 9.9 19.594 18 35.9 43 35 210 100 Se 0.29 Ag <0.5 4.5 Sn 5 20 300 50 Tl 0.1-0.8 U 0.7-9 V 50 Zn 7-38 98 123.1 315 520 140 720 500 * NOAA Screening Quick Reference Tables (SQuiRTs) (NOAA, 1999). LTEL; Lowest ARCs H. azteca Threshold Effects Level, TEL: Threshold Effects Level, PEL: Probable Effects Level, UET: Upper Effects Threshold. The ‘Background’ values is obtained from fresh water sediments. ** Guide values and quality standards used in the Netherlands for assessing soil contamination. Ref.: Reference value, Interv.: Intervention value, Test: Test value (Alloway, 1995) *** Critical soil total concentration: the range of values above which toxicity is considered to be possible (Kabata-Pendias and Pendias in Alloway,1995) EQS soil: Environmental Quality Standards for Soil (Japan) IV. Concluding Remarks The result of interpretation and assessment on spatial distribution of PTEs is summarized in Table 4. Based on the spatial distribution pattern of each element concentration, we estimated the background value for each element. The background values are mostly within normal level in comparing with the international background values, but the background of As, Ni, and Sb shows rather higher values, which may be a characteristic feature of this region. The spatial distribution of PTEs indicates that high anomaly of PTEs concentration in soil/sediment often appears in Tunis urban zone and its south, the agricultural zone between Tunis and Zaghouan. These areas are probably much contaminated by human activities; urbanization, industries, waste disposal and so on. Comparing the concentration level of each anomaly with the international standards (Table 3), the concentration of seven PTEs, As, Cd, Cu, Hg, Pb, Sb, and Zn, indicates abnormal high values that exceed the environmental quality standards, which is potentially hazardous (see the Risk column in Table 4).

However, for assessing environmental impacts of human activities, we have to enhance the data interpretation. We will plan to establish a Geographic Information System (GIS) for a detailed interpretation in near future.


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Table 4: Summary of the soil/sediment contamination screening

PTEs Background*unit: mg/kg

Anomaly Risk Possible polluters

As <7.7 (high)

Agricultural zone between Tunis and Zaghouan

high at anomaly

Natural, Agriculture, Urban, Waste

B <6.6 (normal)

Lake Tunis to Carthage; agricultural zone between Hammamet and Zaghouan

low Natural, Waste

Cd <0.15 (normal)

Tunis urban zone and its south high at hotspot

Urban, Waste, Agreiculture

Co <6.1 (low)

Tunis urban zone to the agricultural zone between Tunis and Zaghouan

low Natural, Urban, Waste

Cr <17.1 (high)


low Urban, Industrial, Waste

Cu <19.4 (normal)

Tunis urban zone, especially Lake Tunis

high at hotspot

Urban, Industrial, Waste

Hg <0.055 (normal)

Agricultural zone between Tunis and Zaghouan

high at hotspot

Natural, Waste, Agricultural

Mo <0.55 (low)

Rades Industrial Zone low Industrial (Fuel burning?)

Ni <11.1 (high)


low Urban, Waste, Industrial

Pb <17.9 (normal)

Tunis urban zone high at hotspot

Urban, Industrial, Waste

Sb <0.4 (high)

Agricultural zone between Grombalia and Nabeul

high at hotspot

Natural (?), Waste, Industrial (?)

Se <0.12 (normal)

Coastal zone between Tunis and Hammam-Lif

low Urban, Waste, Natural

Zn <26.4 (normal)

Tunis urban zone and its surroundings

high at hotspot

Urban, Waste, Industrial

* ( ) gives the comparison with international background values (see Table 3). Acknowledgements We thank Ali M’hiri (INAT) for his kind advice and Naceur Jedidi (INRST) for his supports in laboratory works. References Alloway, B.J., 1995(ed.), Heavy Metals in Soils, 2nd Edition. Blackie Academic &

Professional, Chapman & Hall, London, 368p. De Groot, A.J., 1995, Metal and sediments: A global perspective. In Allen, H.E. (ed.), Metal

Contaminated Aquatic Sediments, Ann Arbor Press, 1-20. Gurrieri, J.T., 1998, Distribution of metals in water and sediment and effects on aquatic biota

in the upper Stillwater River basin, Montana. Jour.Geochem.Explor., 64, 83-100. Odor, L., Wanty, R.B., Horvath, I, and Fugedi, U., 1998, Mobilization and attenuation of

metals downstream from a basee-metal mining site in the Matra Mountains, northeastern Hungary. Jour.Geochem.Explor.,65, 47-60.

Ure, A.M., 1995, Methods of analysis for heavy metals in soils. In Alloway (ed.), Heavy Metals in Soils, 2nd Edition. Blackie Academic & Professional, Chapman & Hall, London, 58-102.

soil/sediment contamination in northeastern tunisia: a...

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