Environmental Science and Pollution Research

, Volume 19, Issue 2, pp 559–576

Aliphatic hydrocarbons, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, organochlorine, and organophosphorous pesticides in surface sediments from the Arc river and the Berre lagoon, France

  • Fehmi Kanzari
  • Agung Dhamar Syakti
  • Laurence Asia
  • Laure Malleret
  • Gilbert Mille
  • Bassem Jamoussi
  • Manef Abderrabba
  • Pierre Doumenq
Research Article

DOI: 10.1007/s11356-011-0582-5

Cite this article as:
Kanzari, F., Syakti, A.D., Asia, L. et al. Environ Sci Pollut Res (2012) 19: 559. doi:10.1007/s11356-011-0582-5

Abstract

Introduction

The Arc River and Berre lagoon are one of important river basin hydrosystem in the South of France that receives industrial and municipal wastewaters from the adjacent area.

Materials and methods

Due to its social and economic impact as well as ecological function of basin, an assessment of environmental risk due to mobilization of contaminants is necessary. Thus, the study aims to determine the spatial distribution of n-alkanes, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine and organophosphorous pesticides in surface sediments and their potential origins by using gas chromatography coupled to mass spectrometry.

Results and discussion

Total alkanes concentrations ranged from 563 to 5,068 μg kg−1 sediment dry weight (dw), the sum of 17 PAHs ranged from 153 to 1,311 μg kg−1 dw, the sum of seven PCBs concentrations ranged from 0.3 to 466.8 μg kg−1 dw, and the total pesticides concentrations ranged from 0.02 to 7.15 μg kg−1 dw. Ratios of specific n-alcanes (carbon preference index, natural n-alkanes ratio, and terrigenous/aquatic ratio) and ratios of selected PAH (anthracene (Ant)/(Ant + Phe), fluoranthene (Fl)/(Fl + pyrène (Pyr)), BaA/(BaA + chrysene (Chry)), indeno[1,2,3,c,d]pyrene (IPyr)/(IPyr + BghiP)) were calculated to evaluate the possible sources of hydrocarbons.

Conclusions

The evaluations suggest the sources of hydrocarbons in the sediments were generally biogenic and markedly more pyrolytic rather than petrogenic. In the perspectives of environmental risk assessment, all contaminants levels were also compared with sediments quality guidelines (SQG) resulting that the contamination levels in all stations were most of the time lower than their respective SQG. While, for PCBs concentrations, three stations (A8, B1, and B2) were higher than their effect range median values which may indicate high potential toxicity of the sediment with probable adverse effects to the living biota.

Keywords

Persistent organic compounds River basin Environmental chemistry Urban, agricultural, and industrial effluents 

1 Introduction

A key component of the European Water Framework Directive is the development of river basin management plans which should be established in order to set environmental quality objectives. One of the important steps is to study both environmental quality standards for the water bodies and emission limit values for any discharge of effluent.

The Arc River and Berre lagoon are an important hydrosystem in the South of France and their quality is strongly affected by past and present industrial activities and by an intense urbanization. Due to its social and economic impact as well as ecological function of basin, an assessment of environmental risk due to mobilization of contaminants is necessary. The Berre lagoon located in downstream of the Arc River finally may receive the drains one of the most industrialized valleys of the Arc watershed, which results in both biogenic and anthropogenic matters, reflected by the occurrence of following contaminants models: hydrocarbons (n-alkanes) and polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine (OCs), and organophosphorous pesticides (OPs).

Hydrocarbons are widespread contaminants in rivers and lagoons, and major hydrocarbons are mostly n-alkanes and polycyclic aromatic hydrocarbons (PAHs) (Medeiros et al., 2005). In the study area, hydrocarbons may derive from (1) oil spills and discharge of petroleum and transformed products (petrogenic source), (2) incomplete combustion of organic material, especially biomass and fossil fuels (pyrogenic source), (3) natural inputs from continental higher plants and marine biomass and their products from the postdepositional transformation of biogenic precursors (diagenetic origin; Mille et al. 2007; Asia et al. 2009).

n-Alkanes can be released into the environment by the metabolic activity of aquatic organisms and terrestrial plants or from their decomposition. They are formed by chemical or biological decarboxilation affecting linear and branched fatty acids or synthesized by algae and bacteria. The n-alkanes, specific to marine organisms, have a number of carbon atoms less than 21 with a particular predominance of nC15 and nC17 (Mille et al. 2007). In petroleum-polluted sediments, saturated hydrocarbons generally have a regular distribution, ranging from C12 to C40. Odd numbered n-alkanes are considered as biomarkers organic matter derived from terrestrial plants.

PAHs represent a family of more than 100 organic molecules comprising at least two aromatic cycles. They are divided into two categories: low-weight molecular compounds (less than 4 aromatic cycles) and compounds of high molecular weight (4 cycles or more). The physical and chemical properties of PAHs vary according to their molecular weight and their structure. PAHs represent a complex mixture of compounds originating from the incomplete combustion of organic matter. PAHs are hydrophobic molecules. They are classified as persistent organic pollutants (POPs) by the United Nations Environmental Program (UNEP 2001). Therefore, clues to the source of PAHs can be obtained by molecular indices based on ratios of individual PAH concentrations in the sediments (Budzinsky et al. 1997).

PCBs are ubiquitous POPs. Their toxicity varied with their molecular weight (number of chlorine) and the spatial configuration of the molecules. These bioaccumulative contaminants are found in human fatty tissues and in human milk. Part of the world production has been destroyed but important amounts remain in use or await destruction, while unknown amounts of PCBs are still present in various environmental compartments. Surficial sediments therefore constitute one of the primary locations for PCB accumulation in the environment as confirmed by numerous studies (Cardellicchio et al. 2007; Vane et al. 2007; Zhao et al. 2010). PCBs were mainly used between the 1930s and the 1970s as lubricants for the manufacture of electrical transformers, capacitors, or as insulators in environments with high voltage because of their relative low flammability and their excellent dielectric properties. They have also been used as coolants (in environments with fire risk, including vessels carrying fuel), or as hydraulic fluids in hazardous environments or thermal stress (mines…). They were also used in pump motors, microwave ovens, or as oil additives or products of welds in some adhesives, paints, and even in carbonless paper.

At European level, France remains the first consumer of pesticides (30% of total consumption) and the fourth in the world behind the USA, Brazil, and Japan. Compounds selected in this study are pesticides used in agriculture and which are listed in the priority Directive 60/2000/EU. OCs and OPs pesticides are released into the environment following their use as insecticides, fungicides, and herbicides. The generated wastes are multiple and largely spread throughout the national territory in relation to their application in the field. The pesticides studied in the present work, which have a broad range of uses (Navarro-Ortega et al. 2010), cover several families of organochlorine (α-HCH; lindane; aldrin; isodrin; dieldrin; endrin; endosulfan I and II; o,p′-DDE, p,p′-DDE, o,p′-DDT, and p,p′-DDT); organophosphorus (chlorpyrifos and chlorfenvinphos); and dinitroanilines (trifluralin) compounds.

Thus, in the light of above, and due to the intense anthropic forcing in this area, including industrial as well as agricultural activities, this study may help to link studied pollutants occurrence and sources, which have potential harmful effects for living biota and human health.

That is why this study aims to explore the spatial distribution of n-alkanes, PAHs, PCBs, and organochlorine and organophosphorous pesticides in surface sediments of the Arc river and the Berre lagoon and to determine their potential origins. With increasing concern about the toxic effect of those contaminants on food safety and human health through food chain, this study is also an attempt to provide an evaluation of the possible environmental risk through a Sediment Quality Guidelines comparative study database from National Ocean and Atmosphere Administration (NOAA).

2 Materials and methods

2.1 Site description

The Provence Arc river is about 83 km long, with an east–west flow (Fig. 1). The spring source is located in Pourcieux, then the river crosses Aix-en-Provence, Arbois plateau, Roquefavour gorge, before emptying into the Berre lagoon northwest of Marseille. The hydrological regime, typically Mediterranean, is highly variable, with a water flow of some 1–1,000 m3 s−1 in times of flood. The catchment area forms a basin of 1,700 km2, supporting a population of over 500,000 inhabitants and is drained by four rivers including the Arc (Desenfant et al. 2004). In the upper Arc river basin located in the southeast part of Aix en Provence, an intensive agriculture, predominantly vineyard, wheat and olive orchards, is present. The agricultural zone located at the mouth of the Arc, in Berre lagoon, mainly produces vegetables (tomatoes, peppers, cucumbers, and salads…) and makes the Bouches-du-Rhone the leader of vegetable production in France.
Fig. 1

Location of sampling sites of the Arc river (A1–A16) and the Berre lagoon (B1 and B2)

The industry is also very present in the watershed of the Arc with the industrial estate of Rousset/Peynier in the upper valley of the Arc dominated by microelectronics, the “historical” mining area of Gardanne, the industrial and commercial areas in the south of Aix-en-Provence, and also the petrochemical complex of Berre.

2.2 Sampling

Sampling of the Arc river and the Berre lagoon was carried out from January 2008 to May 2010. Sampling strategy (Fig. 1) consists of 16 sampling sites on the Arc river (A1–A16) and two sampling sites on the Berre lagoon (B1 and B2). Sites were selected to be representative of the different human activities, e.g., industries, refineries activities, urban activities (wastewater), and agriculture. A Global Positioning System (Garmin Etrex summit HC, Kansas City, MO, USA) and Geographic Information Systems (MapInfo Professionnal 7.5, Boulogne-Billancourt, France) were used to target the different sites. Each surficial sediment (0–5 cm) was collected using a stainless steel shovel previously rinsed with CH2Cl2 (DCM), then immediately stored in aluminum container and stored in an isotherm container (±4°C) in order to minimize microbial degradation during transport to the laboratory. Sediments samples were subsequently freeze dried during 3 days (Christ Alpha1 4, Bioblock Scientific, Charvieu Chavagneux, Rhône Alpes), sieved with a stainless steel sieves at 200 μm, and finally homogenized before analysis.

2.3 Chemicals

All solvents used for the analyses (n-hexane (HEX), acetone (ACE), methylene chloride (DCM), and n-heptane) were of SupraSolv grade (Merck, Darmstadt, Germany). Individual analytical internal standards (phenanthrene-d10 and chrysene-d12; CIL, Andover, MA, USA; n-nonadecane-d40 and Mirex PESTANAL; Sigma-Aldrich, St Louis, MO, USA) and mixture standard (PAH Mix 25, US Environmental Protection Agency (EPA) 16, and PCB-Mix 3; Dr. Ehrenstorfer Laboratories, Augsburg, Germany) were used for identification and quantification. Individual pesticide standards (α-HCH; lindane; aldrin; isodrin; dieldrin; endrin; endosulfan I; endosulfan II; chlorpyrifos; chlorfenvinphos; trifluralin; o,p′-DDE, p,p′-DDE, o,p′-DDT, and p,p′-DDT) were obtained from Dr. Ehrenstorfer (Augsburg, Germany).

2.4 Extraction and separation

About 10 g accurately weighted of freeze-dried sediment were transferred into a precleaned cellulose extraction thimble and extracted by soxhlet extractor apparatus for 16 h with a 200 ml mixture of SupraSolv grade DCM and HEX (1:1, V/V). Internal standards (phenanthrene-d10 and chrysene-d12) were added to the sample aliquot before extraction. The extract was then concentrated to about 2 ml with a rotary evaporator for the following separation/cleanup step. Long chain n-alkanes (nC14-34) and PAHs were separated using a 1.0 × 30 cm glass chromatography column with 8 g of silica gel and 8 g of alumina (bottom and top of the column, respectively). Before use, adsorbents were deactivated with 5% w:w distilled H2O. Aliphatic fraction (F1) was eluted with 30 mL of n-heptane and 20 mL of n-heptane/DCM (90:10). Elution with 40 ml of n-heptane/DCM (80:20) yielded to aromatic fraction (F2). Sulfur interference was removed by shaking the extract with powder copper previously washed with diluted hydrochloric acid. Both fractions were then evaporated on a rotary evaporator and then under a gentle stream of nitrogen.

The method used to extract PCBs and pesticides was based on that previously described by Villaverde et al. (2008) and Zhao et al. (2010). Briefly, 10 g of sediments were spiked with 500 μL of internal standards (Mirex), mixed with 3 g of alumina and 3 g of copper powder, extracted with HEX/ACE (1:1, V/V) in an accelerated solvent extraction system ASE 200 (Dionex, USA). The accelerated solvent extraction (ASE) extraction parameters were 100°C, 1,500 psi, 5 min of heating, 5 min of static time, 60 s of nitrogen purge, and twop extraction cycles. No further clean-up was performed after this “one-step” extraction/cleanup procedure for PCBs extracts. The pesticides extracts were then fractionated and cleaned-up using 5 g of 3% deactivated alumina (top) and 7.5 g of 5% deactivated silica gel (bottom) in a bilayer chromatographic column. Pesticides were then collected by combining two successive fractions eluted with 50 mL (3:2/v:v) and 30 mL (1:3/v:v) of HEX/DCM.

2.5 Analysis by capillary gas chromatography coupled to mass spectrometry

F1, F2, PCBs, and pesticide fractions were analyzed by gas chromatography coupled to mass spectrometry (GC/MS; Autosystem XL GC and TurboMass from Perkin Elmer, USA). Chromatographic conditions were as follows: splitless injection (30 s), Elite 5MS column (30 m × 0.25 mm i.d. × 0.25 μm film thickness). For F1 and F2 fractions, the GC oven was temperature-programmed from 40°C (2 min) then raised to 120°C (45°C min−1) and then raised to 310°C (5°C min−1) and finally held isothermally for 20 min. For PCBs fractions, the oven was programmed as follows: 100°C (3 min) then raised to 290°C (6°C min−1) and finally held isothermally for 10 min. For organochlorine and organophosphorous pesticides, the oven was programmed as follows: 70°C (2 min), then raised to 175°C (10°C min−1) and held isothermally for 4 min, then raised to 320°C (5°C min−1) and finally held isothermally for 1 min. Helium (1 mL min−1) was used as carrier gas in constant flow mode.

The mass spectrometer was operated in the electron ionization mode (70 eV) and simultaneously scanned in both full scan and selected ion monitoring (SIFI mode). Individual n-alkanes were quantified using a deuterated internal standard (n-non-adecane-d40m/z 66). For PAH analysis, the 16 US EPA priority PAHs were identified from retention time and m/z ratios, and then quantified using deuterated internal standards (phenanthrene-d10m/z 188 and chrysene-d12m/z 240). The seven PCBs and pesticides were quantified with Mirex (m/z 235-274) as internal standard.

Abbreviations and diagnostic ions used for PAHs, PCBs and pesticides are as following: acenaphthylene (Ac, m/z 152); acenaphthene (ace, m/z 153); anthracene (Ant, m/z 178); chrysene (chry, m/z 228); fluoranthene (Fl, m/z 202); fluorene (F, m/z 166); phenanthrene (Phen, m/z 178); pyrène (Pyr, m/z 202); naphthalene (Na, m/z 128); benzo[a]anthracène (B[a]A, m/z 228); benz[a]pyrene (B[a]Pyr, m/z 252); benz[e]pyrene (B[e]Pyr, m/z 252); benzo[b]fluoranthene (B[b]Fl, m/z 252); benzo[k]fluoanthene (B[k]Fl, m/z 252); benzo[g,h,i]perylene (B[g,h,i]P, m/z 276); dibenz[a,h]anthracene (dB[a,h]Ant, m/z 278); indeno[1,2,3,c,d]pyrene (IPyr, m/z 276); CB28 (2,4,4′-trichlorobiphenyl; m/z 186-256); CB52 (2,2′,5,5′-tetrachlorobiphenyl; m/z 220-255-292); CB101 (2, 2′, 4, 5, 5′-pentachlorobiphenyl; m/z 254-291-326); CB118 (2, 3′, 4, 4′, 5-pentachlorobiphenyl; m/z 254-291-326); CB138 (2, 2′, 3, 4, 4′, 5′-hexachlorobiphenyl; m/z 290-325-360); CB153 (2,2′,4,4′,5,5′-hexachlorobiphenyl; m/z 290-325-360); CB180 (2,2′,3,4,4′,5,5′-heptachlorobiphenyl; m/z 324-359-394); α-HCH (m/z 181-219-109), lindane (m/z 181-219-109), aldrin (m/z 66-263-293), isodrin (m/z 66-193-263), dieldrin (m/z 79-263), endrin (m/z 81-263), endosulfan I (m/z 195-241-339), endosulfan II (m/z 159-195-241), chlorpyrifos (m/z 97-197-314), chlorfenvinphos (m/z 267-323), trifluralin (m/z 264-306); o,p′-DDE (m/z 246), p,p′-DDE (m/z 246), o,p′-DDT (m/z 235), and p,p′-DDT (m/z 235).

2.6 Quality control and quality assurance

All data were subject to quality and control procedures. Laboratory blanks and matrix duplicate samples were analyzed as quality control measurements. Two labeled PAHs (phenanthrene-d10 and chrysene-d12) and one labeled n-alkane (n-nonadecane-d40) were added to each sample and matrix blank prior to extraction as surrogates to assess the overall procedural recovery. In this study, PAH and n-alkane surrogate recoveries were 90%, 102%, and 110% for phenanthrene-d10, chrysene-d12, and n-nonadecane-d40, respectively. Mirex was used to measure the recoveries for PCBs and pesticides. Average percent recoveries of PCBs and pesticides were 88–97% and 90–105%, respectively. Matrix blanks were analyzed using the same procedures as for the samples. The mass of each individual PAH, PCBs, and pesticides in the blanks was insignificant relative to that of the sediment samples. The relative standard deviations percent were between 1.3% and 4.5% for PAHs, 3% and 22% for PCBs and pesticides compounds.

The detection limits of PAHs, PCBs, and pesticides were determined as the content of analyses in a sample that gives rise to a peak with a signal-to-noise ratio (S/N) to 3. The detection limits of PAHs, PCBs, and pesticides at an S/N of 3 were 0.01–0.26, 0.01–0.06, and 0.006–1 μg kg−1, respectively, of sediment dry weight (dw).

3 Results and discussion

Gravimetric data is given in Table 1. Extractable organic matter (EOM) concentrations in sediments vary from 160 to 5,400 mg kg−1 dw. The lowest values (<500 mg kg−1 dw) are observed at stations A1, A2, A5, A6, A7, A10, and A14 and the highest values (>500 mg kg−1 sediment dry weight) are found at stations A3, A4, A8, A9, A11, A12, A13, A15, A16, B1, and B2. Total hydrocarbon concentrations (THC) vary from about 100 mg kg−1 (station A2 and A16) to 2,560 mg kg−1 dw (station A12). This concentration range is generally typical of unpolluted to moderately polluted river sediments (Mille et al. 2007). The proportions of THC in EOM are between 11% (station A9) and 83% (stations B1) which explains the presence of predominantly polar compounds. In the same time, the proportion of aromatic hydrocarbons (6–53%) remains stable and lower than the proportion of aliphatic hydrocarbons (47–94%).
Table 1

Gravimetric data (mg kg−1 sediment dry weight) and ratios

Stations

EOM

THC

F1

F2

THC/EOM%

F1/THC%

F2/THC%

F1/F2

A1

230

120

80

40

52

67

33

2

A2

160

100

80

20

63

80

20

4

A3

770

180

150

30

23

83

17

5

A4

1,510

250

220

30

17

88

12

7

A5

320

177

157

20

55

89

11

8

A6

490

210

170

40

43

81

19

4

A7

320

250

160

90

78

64

36

2

A8

900

220

140

80

24

64

36

2

A9

2,280

260

160

100

11

62

38

2

A10

470

150

70

80

32

47

53

1

A11

940

230

180

50

24

78

22

4

A12

5,400

2,560

2,380

180

47

93

7

13

A13

1,740

980

920

60

56

94

6

15

A14

470

120

70

50

26

58

42

1

A15

1,040

310

220

90

30

71

29

2

A16

530

100

80

20

19

80

20

4

B1

2,370

1,960

1,830

130

83

93

7

14

B2

1,350

1,620

1,420

200

18

83

17

5

EOM extractable organic matter, THC total hydrocarbon concentration, F1 saturated hydrocarbon fraction, F2 polycyclic aromatic hydrocarbon fraction

3.1 Distribution and sources of n-alkanes

GC patterns of aliphatic hydrocarbons in analyzed sediments comprise a series of resolved compounds (n-alkanes and some branched alkanes such as pristane and phytane) and an “Unresolved Complex Mixture” (UCM). UCM is the sign of a petroleum input and/or the presence of a biodegraded complex mixture of hydrocarbons and is considered to be the result of many co-elutions of structurally complex isomers and homologues of branched and cyclic hydrocarbons (Gough and Rowland, 1990). The UCM, ranging from C14 to C34, is unimodal (stations A2, A3, A4, A5, A6, A7, A9, A11, A12, A13, A14, A15, A16, B1, and B2) or bimodal (stations A8 and A10; Fig. 2). These bimodal UCMs suggest the presence of both light and heavy petroleum-derived compounds but can also be an indication of coexistence between a recent and an old pollution.
Fig. 2

Capillary column gas chromatograms of the saturated hydrocarbons fractions (stations A1, A8, A12 and B1). Numbers indicate n-alkanes (carbon chair length), UCM unresolved complex mixture, IS internal standard (non-adecane-d40)

Long chain alkanes (C14–34) were measured for all sediment samples. The sediment concentrations showed large variation among sampling sites and ranged from 563 to 5,068 μg kg−1 dw (Table 2). Contamination levels found in sediments are similar to those determined in France by Charriau et al. (2009) in the channel Espierre (4,400–4,900 μg kg−1 dw) but lower than those measured in sediments from the Scheldt River (10,900-13,700 μg kg−1 dw), its tributary, the Lys (17,200-29,400 μg kg−1 dw) and the Moselle river (5,900–10,300 μg kg−1 dw; Jeanneau et al. 2006). Sediments collected from stations A1, A2, A4, A5, A7, A12, and B2 have the higher alkane concentration, ranging from 3,001 to 5,068 μg kg−1 dw. For the other sites (Arc river and the Berre lagoon), concentrations were lower, ranging from 563 to 2,656 μg kg−1 dw. The most dominant compounds found in the whole sediments are nC27, nC29, nC31, and nC33 (Table 2). Light n-alkanes C14–20 are often less abundant than heavier alkanes C21–34.
Table 2

Concentration (μg kg−1 dry weight) of alkanes, pristane and phytane in sediment samples from the Arc River (stations A1–A16) and the Berre Lagoon (B1 and B2)

Stations

A1

A2

A3

A4

A5

A6

A7

A8

A9

A10

A11

A12

A13

A14

A15

A16

B1

B2

n-C14

0.2

0.9

1.0

1.5

5.7

0.2

1.0

5.1

0.2

0.1

2.6

1.3

0.3

0.1

2.6

1.2

0.4

0.5

n-C15

0.2

1.3

1.8

5.5

5.8

0.2

1.0

2.5

0.2

0.1

7.9

15.2

0.4

0.2

8.0

0.8

2.8

13.2

n-C16

1.2

0.6

1.4

2.6

4.2

0.7

4.7

3.5

0.4

0.2

9.3

7.0

0.1

0.3

8.5

10.4

0.3

25.4

n-C17

4.3

13.5

5.7

5.8

8.6

2.6

42.4

9.1

2.6

0.2

21.6

13.4

3.8

1.2

22.1

41.5

0.7

68.0

Pra

4.3

9.0

5.8

4.5

8.0

2.5

25.9

8.4

2.1

0.1

15.8

10.4

3.9

0.9

15.7

35.4

0.5

39.4

n-C18

15.6

61.2

8.3

11.7

9.7

3.6

64.2

18.2

9.7

2.9

30.3

65.3

8.5

6.1

30.3

43.0

16.1

41.6

Phyb

17.4

61.2

12.9

11.8

11.7

5.5

59.3

17.5

7.8

4.0

26.9

70.4

8,0

5.7

25.9

47.8

14.4

61.0

n-C19

12.3

69.0

6.0

13.6

7.8

4.3

48.6

15.6

12.0

9.4

25.3

7.4

11.7

6.8

24.7

30.1

21.7

37.3

n-C20

14.7

75.3

9.1

20.4

12.9

5.3

55.1

18.1

11.5

19.1

31.1

7.8

13.4

6.9

27.0

29.3

27.2

40.7

n-C21

101.5

54.6

5.1

26.1

13.9

7.7

56.9

20.2

49.0

26.7

25.9

6.7

20.0

5.6

27.5

34.9

36.1

53.4

n-C22

32.2

84.6

8.3

34.2

13.7

9.2

66.9

26.0

29.1

48.0

22.3

7.6

27.2

5.3

25.5

38.9

30.2

50.1

n-C23

74.5

84.4

10.2

56.9

40.0

17.9

100.7

25.7

66.4

67.7

30.2

10.4

69.8

8.4

31.3

59.3

40.9

71.0

n-C24

46.6

89.6

7.4

54.4

41.8

17.1

61.8

16.3

42.5

62.3

21.4

8.8

63.7

6.6

21.6

43.3

26.2

60.5

n-C25

80.2

107.1

28.4

161.9

167.5

52.0

184.9

33.6

111.3

71.1

90.8

20.1

172.7

15.3

84.4

85.9

59.7

164.1

n-C26

50.5

65.0

16.2

59.5

63.0

43.2

86.7

25.9

46.1

43.7

32.4

11.3

69.4

9.0

30.6

39.7

27.4

74.0

n-C27

367.1

410.4

157.2

1024.9

1354.8

264.6

1019.0

124.5

360.8

118.6

204.7

86.1

1007.6

68.0

218.5

419.2

161.6

733.7

n-C28

86.4

72.5

28.7

109.9

137.6

99.4

169.2

46.6

87.0

43.3

64.7

21.4

61.9

20.4

70.5

55.5

48.9

164.8

n-C29

666.1

734.8

204.1

1007.6

1450.9

455.9

1331.9

168.5

562.8

167.4

302.8

157.4

1007.1

135.3

317.6

704.3

303.2

851.5

n-C30

67.2

100.8

34.8

98.7

117.0

76.6

186.4

33.3

97.6

29.5

55.2

24.7

77.5

22.7

60.2

68.3

45.1

77.4

n-C31

670.0

708.8

192.1

862.4

965.5

385.3

1046.6

150.8

489.1

144.3

310.1

152.9

771.9

158.4

308.1

647.7

341.8

655.8

n-C32

130.3

53.7

20.5

80.1

99.1

38.9

115.1

31.1

57.0

14.4

39.0

13.8

57.6

17.2

41.6

37.6

33.4

66.8

n-C33

153.6

125.9

56.4

270.4

351.4

97.9

300.4

62.1

230.4

46.9

121.5

44.2

246.4

49.8

129.3

140.6

143.6

211.3

n-C34

59.7

16.7

10.5

59.7

74.9

24.6

39.7

16.2

35.6

12.0

31.7

8.1

22.0

12.7

33.1

16.5

16.3

54.6

alk

2656.1

3000.8

831.9

3984.1

4965.3

1615.2

5068.5

878.5

2311.0

932.0

1523.7

771.5

3724.7

563.0

1564.4

2631.2

1398.5

3616.1

n-C17/Pr

0.9

1.0

0.9

0.9

0.8

1.0

1.1

0.9

1.0

0.7

1.1

0.7

0.8

1.1

0.9

0.9

1.4

1.7

n-C18/Phy

1.0

1.5

1.0

2.0

1.1

1.5

1.6

1.1

1.0

1.7

1.4

0.8

0.9

1.3

0.9

1.2

1.1

0.7

Pr/Phy

0.2

0.1

0.4

0.6

0.7

0.6

0.4

0.7

1.0

0.0

0.6

0.9

0.8

0.4

1.0

0.7

0.0

0.6

CPI(24–32)c

2.4

6.3

3.2

3.0

10.2

5.7

6.7

3.7

5.6

3.2

5.0

2.8

5.9

4.4

2.0

9.1

5.7

6.0

TARd

>50

22.1

25.3

12.4

>50

12.9

37.0

5.9

11.7

44.2

14.9

11.1

22.7

7.9

42.1

24.5

32.1

6.4

NARe

0.4

0.6

0.4

0.4

0.8

0.6

0.7

0.5

0.6

0.4

0.6

0.4

0.6

0.5

0.3

0.7

0.6

0.6

LMW/HMWf

0.0

0.1

0.1

0.1

0.0

0.2

0.1

0.3

0.2

0.0

0.1

0.2

0.1

0.2

0.0

0.1

0.1

0.1

aPristane

bPhytane

cCPI Carbon Preference Index calculated as 2(C25 + C27 + C29)/(C24 + 2(C26 + C28 + C30) + C32; Bray and Evans 1961)

dTAR terrigenous/aquatic ratio calculated as (nC27 + nC29 + nC31)/(nC15 + nC17 + nC19; Bourbonniere and Meyers 1996)

eNAR Natural n-alkane ratio calculated as [sum n(C19-C32) − (2*sum n(C20 - C32))]/sum n(C19 - C32; Mille et al. 2007)

fLMW/HMW Sum of low molecular weight [(nC14 to nC20)]/[sum of high molecular weight (nC21 to nC34)] n-alkanes ratio (Gearing et al., 1976)

To assess the possible sources of alkanes in the Arc river and Berre lagoon sediments, we calculated seven diagnostic ratios, namely the carbon preference index (CPI), natural n-alkanes ratio (NAR), terrigenous/aquatic ratio (TAR), the ratio of low molecular weight to high molecular weight (LMW/HMW), the n-C17/Pr, n-C18/Phy, and Pr/Phy.

The CPI displays the ratio between odd numbered n-alkanes and even numbered n-alkanes (Bray and Evans 1961). CPI values, in the range nC24nC32, close to one, are found for all crude oils and petroleum hydrocarbons. A predominance of odd numbered n-alkanes (nC27, nC29, and nC31) is characteristic of terrestrial higher plant debris (Rielley et al. 1991; Fig. 2). For all stations, this ratio is markedly higher than one, which is an evidence of important and recent terrigenous inputs (Table 2).

The NAR (Mille et al. 2007) roughly estimates the proportions of natural and petroleum n-alkanes. These ratios are close to zero for petroleum hydrocarbons and crude oils whereas they are close to one for higher terrestrial plants or marine plants. For all stations, these ratios range between 0.3 and 0.8, in accordance with CPI results. The influence of these terrestrial inputs is well marked in stations A2, A5, A6, A7, A8, A9, A11, A13, A16, B1, and B2.

The TAR (Bourbonniere and Meyers 1996; Mille et al. 2007), which is the ratio between the concentrations of long-chain n-alkanes (nC27 + nC29 + nC31) to short-chain n-alkanes (nC15 + nC17 + nC19), evaluates the importance of terrigenous inputs vs. aquatic inputs. This ratio is very high for all stations (Table 2) and confirms that terrestrial inputs in the Arc river and the Berre lagoon are significant.

The LMW/HMW is the concentration ratio of the low molecular weight (sum of nC14nC20) to high molecular weight (sum of nC21nC34) n-alkanes. It has been reported that LMH/HMW ratios <1 usually represent n-alkanes produced by higher plants, marine animals and sedimentary bacteria, while LMW/HMW ratios close to 1 suggest n-alkanes mainly from petroleum and plankton sources (Gearing et al. 1976; Wang et al. 2006). High LMW/HMW ratios (>2) often indicate the presence of fresh oil in sediments (Commendatore et al. 2000). As summarized in Table 2, the LMW/HMW ratios calculated for the Arc river and the Berre lagoon samples are markedly <1 for all samples, and thus confirm that n-alkanes in the Arc river and the Berre lagoon sediments essentially result from terrigenous inputs.

n-C17/Pr and n-C18/Phy ratios are used to evaluate the presence of oil and the relative (short to mid-term) biodegradation of n-alkanes. Low values of these indexes generally suggest the presence of degraded oils. For all stations except B1 and B2, low ratio values of n-C17/Pr are found, which confirms the presence of preferential degradation of linear n-alkanes rather than branched ones. The low values of n-C18/Phy ratio found at stations A12, A13, A15, and B2 confirm such selective biodegradation phenomena. The high value of Pr/Phy ratio observed in our study may reveal that the contaminations are probably historical, concomitant with continuous input of biogenic origin (UNEP/IOC/IAEA 1992).

3.2 Distribution and sources of PAHs

All sediment samples contain significant levels of PAHs. The total PAH concentration, defined as the sum of the concentrations of all 16 EPA PAH, range from 151 to 1,257 μg kg−1 dw (Table 3). Total PAH concentration was relatively high in sediments collected from stations A5, A6, A7, A8, A10, A12, and B1 (634 to 1,257 μg kg−1 dw; Fig. 3). Furthermore, the latter stations present high amounts for four- to six-ring PAHs (74–98%). The highest PAH concentration was found at station A12, which is located close to an abandoned site formerly used as a wastewater treatment plant (WWTP).
Table 3

Concentration (μg kg−1 dry weight) of PAHs in sediment samples from the Arc River (stations A1–A16) and the Berre Lagoon (B1 and B2)

Stations

A1

A2

A3

A4

A5

A6

A7

A8

A9

A10

A11

A12

A13

A14

A15

A16

B1

B2

Na

0.0

0.0

0.0

0.0

0.6

0.4

0.0

0.0

0.0

0.0

0.0

0.3

0.2

0.6

0.0

0.2

18.4

0.0

Ace

0.5

1.0

1.2

1.8

3.6

2.2

0.4

0.3

0.2

10.9

0.6

4.5

0.4

19.4

2.4

0.2

40.5

0.3

Ac

0.0

0.0

0.0

0.0

0.4

0.2

0.0

0.0

0.0

0.0

0.0

0.6

0.0

0.3

0.0

0.0

27.7

0.0

F

0.1

0.1

0.0

0.2

1.8

2.3

0.3

0.5

0.8

0.0

0.1

9.8

0.0

0.8

0.0

0.3

34.0

1.5

Phe

24.9

25.2

2.2

9.3

21.9

52.2

14.7

46.2

24.0

18.7

21.7

96.5

0.4

11.1

16.6

15.0

48.4

22.0

Ant

1.9

2.3

1.0

2.2

4.5

8.7

4.2

5.2

4.0

4.2

3.8

15.1

0.5

7.1

2.6

1.3

52.0

3.6

Fl

102.9

127.6

60.1

41.9

226.1

178.5

123.5

153.3

87.5

298.6

122.0

255.6

33.4

76.3

99.0

41.3

80.5

53.6

Pyr

93.9

102.6

58.7

34.8

218.6

152.9

118.1

136.9

79.9

156.5

122.4

318.9

38.8

88.6

100.5

58.2

79.2

49.5

B[a]A

36.3

31.6

11.5

16.8

16.2

40.9

244.3

90.9

39.1

63.0

34.0

70.4

20.1

9.6

15.2

11.0

33.5

27.0

Chry

37.6

42.2

11.9

19.7

35.1

41.9

243.9

115.4

48.6

74.3

34.3

103.5

25.6

9.8

20.8

9.6

39.0

32.1

B[b]Fl

39.5

43.6

18.9

35.7

28.0

52.0

70.7

111.6

43.9

141.9

30.6

136.4

38.7

11.1

29.4

7.3

65.4

32.6

B[k]Fl

34.0

34.6

7.0

12.2

31.8

18.3

23.6

37.1

15.6

48.1

11.1

42.7

12.9

3.9

9.5

2.3

41.6

16.5

B[e]Pyr

47.6

29.8

23.3

12.8

16.1

21.1

62.4

83.1

42.0

27.8

23.0

53.6

25.1

5.5

28.0

1.9

59.3

33.9

B[a]Pyr

37.5

29.4

13.2

24.6

25.9

36.0

19.7

64.3

24.1

104.8

21.3

78.7

24.0

7.6

18.3

0.7

58.4

27.0

IPyr

33.5

20.5

12.4

24.9

12.8

21.7

32.5

36.6

14.5

82.0

10.2

51.0

20.4

4.6

11.3

2.0

81.6

24.6

dB[a,h]Ant

21.5

31.7

2.3

4.0

44.5

4.3

6.1

9.1

2.9

13.9

2.2

12.6

4.6

0.6

2.4

0.6

69.3

14.7

B[g,h,i]P

42.2

42.4

10.2

24.5

38.7

21.3

24.3

35.0

15.6

77.8

9.3

60.7

22.9

4.1

10.9

1.2

93.6

35.0

PAHa

542.9

498.2

210.7

252.6

710.6

633.6

926.1

842.4

400.7

1094.8

423.3

1257.0

242.8

255.3

338.2

150.9

853.1

334.0

IPyr/BghiP

1.5

2.1

1.2

1.0

0.9

1.0

1.3

0.9

0.9

1.0

1.1

0.8

0.9

1.0

1.0

1.6

0.4

0.7

BaPyr/Chry

0.7

0.9

0.9

0.8

0.8

0.9

0.9

0.9

0.8

0.8

0.9

0.6

0.7

0.9

0.7

1.1

0.4

0.9

Ant/(Ant + Phe)

0.2

0.2

0.3

0.2

0.2

0.1

0.2

0.6

0.5

0.2

0.2

0.1

0.6

0.4

0.1

0.1

0.1

0.1

Fl/(Fl + Pyr)

0.5

0.5

0.6

0.5

0.5

0.5

0.5

0.5

0.6

0.7

0.5

0.4

0.5

0.5

0.5

0.4

0.6

0.5

BaA/(BaA + Chry)

0.4

0.5

0.5

0.5

0.4

0.5

0.5

0.5

0.4

0.4

0.5

0.4

0.4

0.5

0.4

0.5

0.3

0.5

IPyr/(IPyr + BghiP)

0.6

0.7

0.5

0.5

0.5

0.5

0.6

0.5

0.5

0.5

0.5

0.5

0.5

0.5

0.5

0.6

0.3

0.4

LMW/HMWb

0.1

0.0

0.0

0.1

0.1

0.1

0.0

0.0

0.0

0.0

0.1

0.1

0.0

0.2

0.1

0.1

0.3

0.1

aSum of the 16 US EPA PAH

bSum of two- and three-ring PAH divided by the sum of four- to six-ring PAH

Fig. 3

Capillary column gas chromatogram of the polycyclic aromatic hydrocarbon fraction (station A7). Phen-d10 phenanthrene-d10 (internal standard), Phen phenanthrene, Fl fluoranthene, Py pyrene, Chry-d12 chrysene d12 (internal standard), Chry chrysene, B[b + k]Fl benzo(b)fuoranthene + benzo(k)fuoranthene, B[e]Pyr benzo(e)pyrene, B[a]Pyr benzo(a)pyrene, IPyr indeno(1,2,3,c,d) pyrene, dB[a,h]Ant dibenzo(a,h)pyrene, B[g,h,i]P benzo(g,h,i)perylene

Table 4 compare various river and lagoon locations, including some studies relative to the Mediterranean basin. It indicates that the Arc river and the Berre lagoon are moderately polluted in comparison to other Mediterranean rivers and lagoons. PAH levels in the Arc river and the Berre lagoon were higher than those reported for the Ebro river and the Tiber river, but six to ten times lower that the Thau lagoon, the Seine estuary, the Moselle river, the Mar Piccolo, the Venice lagoon, and the Susquehanna river.
Table 4

Comparisons of PAH concentrations (μg kg−1 dry weight) in different river and lagoon sediments from Mediterranean and various area

 

Sites

Numbers of samples

Min and max concentration (μg kg−1 dw)

References

Italy

Venice Lagoona

65–48,000

La Roccha et al. (1996)

Mar Piccolo, Tarantoa

9

380–12,750

Cardellicchio et al. (2007)

Po Rivera

10

100–1,800

Viganò et al. (2003)

Tiber Rivera

5

157.8–271.6

Patrolecco et al. (2010)

France

Arc Rivera

16

151–1,257

This study

Berre Lagoona

2

334–853

This study

Berre Lagoona

5

38–2,323

Jacquot et al. (1999)

Rhone Deltaa

325–3,182

Lipiatou and Saliot (1991)

Thau Lagoona

15

59–7,679

Leaute (2008)

Moselle River

6

44–3,366

Jeanneau (2007)

Seine Estuary

17

13–12,210

Cachot et al. (2006)

Spain

Ebro Rivera

18

11.2–407

Lacorte et al. (2006)

Tunisia

Bizerta Lagoona

6

1.5–2,500

Louiz et al. (2008)

16

 

Mzoughi et al. (2002)

10

 

Trabelsi and Driss (2005)

Egypt

Nile Rivera

3

305–933

Badawy and Emababy (2010)

UK

Mersey Estuary

20

626–3,766

Vane et Al. (2007)

China

Yellow River

15

10.8–252

Hui et al. (2009)

Yangtze River

6

84.6–620

Hui et al. (2009)

Goa-ping River, Taiwan

12

8–356

Doong and Lin (2004)

USA

Susquehanna River

34

3,276–9,847

Ko et al. (2006)

aMediterranean basin

An Fl/(Fl + Pyr) ratio under 0.4 is usually interpreted as an indication of a petrogenic origin, whereas a ratio over 0.4 is an indication of a pyrogenic source and ratio over 0.5. This attests to the presence of coal, grass and wood of combustion origin (Yunker et al. 2002). For Ant/(Ant + Phe), B[a]A/(B[a]A + Chry), and IPyr/(IPyr + B[g,h,i]P) ratios under 0.1, 0.2, and 0.2 (respectively) a petrogenic origin is inferred, whereas from 0.2 to 0.35 the B[a]A/(B[a]A + Chry) ratio indicates either a petrogenic or a pyrogenic origin. Over 0.35 a pyrogenic origin is implied (Budzinsky et al. 1997). Stations A11, A12, A13, A14, A15, and A16 have values of the ratio Fl/(Fl + Pyr) between 0.4 and 0.5 which indicates a pyrolytic source. Stations A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, B1, and B2, where the values are over 0.5, reflect more a coal/grass/wood combustion origin. At all stations, the ratios Ant/(Ant + Phe), B[a]A/(B[a]A + Chry) and IPyr/(IPyr + B[g,h,i]P) confirm the pyrogenic origin of PAH. Studies have shown that low LMW/HMW (sum of two and three rings PAHs to the sum of more than three rings PAHs) ratios (<1) often indicate PAHs that derive mainly from pyrogenic sources (Wang et al. 2006; Table 3). Correlations between some diagnostic ratios such as (Ant/(Ant + Phe), (B[a]A)/(B[a]A + Chry)), (Ppyr/(IPyr + B[g,h,i]P)) vs. (Fl/(Fl + Pyr)) and (Fl/Pyr) vs. (Phe/Ant) are shown in Figs. 4a–c and in 5, respectively.
Fig. 4

Plot of Ant/(Ant + Phen) (a), B[a]A/(B[a]A + Chry) (b) and IPyr/(IPyr + B[g,h,i]P) (c) vs. Fl/(Fl + Pyr) isomeric ratios

Fig. 5

Specific pyrogenic PAH plots of indeno[1,2,3,c,d]pyrene/Benzo[g,h,i]perylene vs. benz[a]anthracene/Chrysene isomeric ratios

The Ant/(Ant + Phe) vs. Fl/(Fl + Pyr) ratios suggest both petroleum and grass/wood/coal combustion origins. Similar results were obtained using the correlation B[a]A/(B[a]A + Chry) vs. Fl/(Fl + Pyr) and IPyr/(IPyr + B[g,h,i]P) vs. Fl/(Fl + Pyr). Additionally, sediments of the Arc river and the Berre lagoon showed evidence of greater contributions from combustion-derived PAHs, especially for stations A1, A2, A3, A4, A5, A6, A7, A9, A10, and B2 (Fig. 4a–c). More specifically, coal/wood combustion rather than petroleum combustion might be the dominant source of PAHs at these sites. On the other hand, Ant/(Ant + Phe) vs. Fl/(Fl + Pyr) ratios (Fig. 4) indicated that petroleum combustion PAHs predominated at some stations A8, A11, A12, A13, A14, A15, and A16. Thus, the PAHs isomer ratios show that PAHs in the Arc river and the Berre lagoon sediments are primarily derived from combustion sources.

Furthermore, within pyrogenic sources, values of some ratios do exist to differentiate between the different types of emissions (wood, coal/coke, diesel, smelter, creosote, etc.). Moreover, the BaA/Chry and IPyr/BghiP ratios can provide additional information to distinguish between PAHs from various pyrogenic sources. As shown in Fig. 5, comparison of the BaA/Chry and IPyr/BghiP ratios shows a cluster between the smelters and coal inputs. Most stations are close to a smelter and coal source. This can be explained by nearly industrial iron and steel plants and by an aluminum smelter (10–50 km, depending on the station) and coal urban heating no longer used since 1980. These findings are in good agreement with previous work on this area, showing atmospheric transport of PAH from these sources (Sanderson et al. 2004; Cachier et al. 2005). Hence, petrochemical complexes, industrial areas along the Arc river and the very high urbanization (traffic of trucks and cars) are the most probable pyrogenic sources of the PAHs.

3.3 Distribution and sources of PCBs

The concentrations of individual congeners (ICES 7 group) and their sum are presented in Table 5. Total PCB concentrations ranged from 0.3 to 541.4 μg kg−1 dw. The highest PCB concentrations (541.4 and 468.8 μg kg−1 dw) were found at stations B1 and B2 (respectively) in the Berre lagoon, which lies close to petrochemical, industrial, and hydroelectric plants. In the Arc river, we found the highest PCB concentrations (466.8 μg kg−1 dw) at station A8 near the outlet of the Aix-en-Provence WWTP. The proportions of the various PCB congeners in the sediment samples were different. Congeners containing five to seven chlorine atoms accounted for more than 80% of the total PCB with the penta (CB101 and CB118)-, hexachloro (CB153 and CB138)-, and heptachloro (CB180)-congeners much more prominent than the trichloro (CB28)- and tetrachloro (CB52)-congeners. The presence of tetrachloro (CB52)-, pentachloro (CB101 and CB118)-, and hexachloro (CB 138 and CB153)-congeners is consistent with a contribution from the commercial mixtures, which have been widely used in transformers, electrical equipment, and other industries in several countries (Barakat et al. 2002). In France, PCBs in sediments are mainly derived from commercial mixture congeners, DP-6 which is rather close to US Aroclor1260 (Arnoux et al. 1980; Wafo et al. 2006).
Table 5

Concentration (μg kg−1 dry weight) of PCBs in sediment samples from the Arc River (stations A1–A16) and the Berre Lagoon (B1 and B2)

Stations

A1

A2

A3

A4

A5

A6

A7

A8

A9

A10

A11

A12

A13

A14

A15

A16

B1

B2

CB28

0.0

0.0

0.1

0.1

0.1

0.07

0.5

0.6

0.1

1.4

n.d.

2.5

0.5

0.2

2.6

0.1

50.8

40.0

CB52

0.0

0.0

0.1

0.1

0.1

0.16

3.8

9.1

0.7

4.0

n.d.

1.2

0.9

0.5

4.7

0.0

35.4

37.1

CB101

0.2

0.1

0.1

0.7

0.6

0.34

8.0

26.6

7.0

5.8

n.d.

0.8

1.5

0.9

5.0

0.2

30.0

65.9

CB118

0.1

0.1

0.3

0.3

1.9

1.17

5.8

26.9

8.3

7.7

n.d.

10.0

2.0

1.5

10.9

0.5

52.1

82.1

CB153

0.1

0.0

0.1

0.4

2.5

0.41

5.0

90.5

13.5

10.5

n.d.

1.5

2.5

1.2

8.6

0.2

141.6

140.3

CB138

0.1

0.0

0.1

0.3

1.1

0.28

4.5

167.0

20.4

12.0

n.d.

0.6

1.6

2.3

15.0

0.6

144.0

66.3

CB180

0.2

0.0

0.1

0.6

2.8

0.19

1.6

146.1

14.9

5.3

n.d.

0.2

2.7

2.1

8.0

0.1

87.5

36.7

∑PCBa

0.7

0.3

0.9

2.5

9.0

2.6

29.2

466.8

65.0

46.7

n.d.

16.7

11.8

8.8

55.1

1.7

541.4

468.8

aSum of the 7 US EPA PCB; n.d. not determined

PCB contamination levels in the Arc river and the Berre lagoon are comparable to contamination levels of the Mersey estuary (UK), Manzala lake (Egypt), Ontario and Erie lakes (Canada), Tiber river (Spain), and Scheldt river (Belgium) but are five or more times lower than those found in Venice lagoon, the Mar Piccolo, the Ebro river, and the Seine river. They are very high compared to the Rhone river, Thau lagoon, the Nile river, the Yellow river, and the Er–Jen river (Table 6).
Table 6

Comparisons of PCB concentrations (μg kg−1 dry weight) in different river and lagoon sediments

 

Sites

Numbers of samples

Min and max concentrations (μg kg−1 dw)

References

Italy

Venice Lagoona

24

6–1,590

Frignani et al. (2001)

Mar Piccolo, Tarantoa

9

2–1,684

Cardellicchio et al. (2007)

Po Rivera

10

10–126

Viganò et al. (2003)

Arrone Rivera

7

11–196

Bazzanti et al. (1997)

Tiber Rivera

28–770

Puccetti and Leoni (1980)

France

Arc Rivera

16

0.3–466.8

This study

Berre Lagoona

2

468.8–541.4

This study

Rhone Rivera

15

0.6-35

Babut and Miege (2007)

Seine River

3

50–26,000

Chevreuil et al. (1998)

Rhin River

39

33–882

Bericht 175f (2009)

Thau Lagoona

15

0–28.3

Leaute (2008)

Spain

Ebro Rivera

13

5.3–1,772

Fernández et al. (1999)

Egypt

Manzala Lakea

125–330

Yamashita et al. (2000)

Nile Rivera

36

0.3–1.9

El-Kady et al. (2007)

Belgium

Scheldt River

18

105–400

Covaci et al. (2005)

UK

Mersey Estuary

26

0.1–410

Vane et Al. (2007)

Canada

Ontario Lake

2.6–255

Marvin et al. (2004)

Erie Lake

1.9–245

Marvin et al. (2004)

USA

Hudson River, New York

31

80–1,410

Feng et al. (1997)

China

Yellow River

12

1.4–5.3

He et al. (2006)

Er-Jen River

11

2–55

Fu and Wu (2006)

aMediterranean basin

3.4 Distribution and source of pesticides

The concentrations of 11 pesticides ranged from 0.02 to 7.15 μg kg−1 sediment dry weight in surface sediments from the Arc river and the Berre lagoon (Table 7). The organochlorine pesticides, α-HCH, aldrin, p,p′-DDT and isodrin were not detected in any sediment samples, probably because they were banned by in France during the early 1990s. As can be seen in Table 7, the levels of pesticides were detected in very low concentrations. Analyzed compounds can be divided into two groups. The first group has low occurrence in sediments such as trifluraline, lindane, endosulfane I, endosulfane II, and dieldrin, with the average concentration of 0.08, 0.78, 0.19, 0.06, and 1.39 μg kg−1 dw, respectively. The second group is present in most of the sediments such as chlorpyrifos (0.01-0.02 μg kg−1), chlorfenvinphos (0.01-0.22 μg kg−1), endrin (0.01–3.30 μg kg−1), o,p′-DDE (0.34–0.68 μg kg−1), and p,p′-DDT (0.38–1.24 μg kg−1).
Table 7

Concentration (μg kg−1 dry weight) of Pesticides in sediment samples from the Arc River (stations A1–A16) and the Berre Lagoon (B1 and B2)

Stations

A1

A2

A3

A4

A5

A6

A7

A8

A9

A10

A11

A12

A13

A14

A15

A16

B1

B2

Trifluraline

0.08

α-HCH

-

Lindane

6.78

Chlopyrifos

0.01

0.01

0.02

0.01

0.01

0.02

Aldrine

Isodrine

Chlorfenvinphos

0.22

0.01

0.03

0.07

0.1

0.06

0.08

0.06

0.09

0.16

0.22

0.05

0.09

0.01

0.02

0.03

Endosulfan I

0.19

Dieldrin

1.39

Endrin

1.70

0.01

0.11

0.02

0.10

0.11

0.30

0.01

0.02

3.30

1.07

0.01

0.31

0.02

0.05

0.04

Endosulfan II

0.06

o,p′-DDE

0.68

0.44

0.34

0.35

0.34

p,p′-DDE

0.99

0.93

5.96

1.10

0.97

1.23

0.67

1.03

0.58

1.09

o,p′-DDT

p,p′-DDT

0.85

0.64

1.24

0.99

0.38

0.43

0.62

∑DDEa

1.67

0.93

6.40

1.10

0.97

1.23

1.01

1.38

0.92

1.09

∑DDTb

0.85

0.64

1.24

0.99

0.38

0.43

0.62

∑OC-OPc

1.98

0.02

0.03

7.15

0.13

0.10

0.17

0.38

0.09

0.11

4.95

1.30

0.06

0.41

0.03

0.07

0.09

a∑DDE = (o,p′-DDE + p,p′-DDE)

b∑DDT = (o,p′-DDT + p,p′-DDT)

c∑OCP-OPP = (trifluraline + α-HCH + lindane + chlopyrifos + aldrine + isodrine + chlorfenvinphos + endosulfan I + dieldrin + endrin + endosulfan II)

Lindane residue was only found at station A5 with a significant level of 6.78 μg kg−1 sediment dry weight. The catchments of the Arc river include many farmlands devoted to intensive agriculture (vineyards and wheat production) and receives effluents of two domestic WWTP and two villages of 10,000 inhabitants downstream from A5. Lindane is still officially used for termite control and seed growth.

Residues of p,p′-DDE were found in nine samples of the Arc river (station A3, A4, A5, A6, A8, A9, A12, A15, and A16) and in one sample of the Berre lagoon (B2). The highest concentration of p,p′-DDE and p,p ′-DDT are found at station A5; they are 5.96 and 1.24 μg kg−1, respectively. This could be explained by the presence in the vicinity of an old industrial site, closed in 1996, formerly used as a factory for commercial pesticide formulation. Almost all of the stations located in this industrial area are moderately contaminated by the o,p′-DDE, p,p′-DDE, and p,p′-DDT.

Chlorpyrifos is present at stations A6, A10, A12, A13, A15, and B2. The surrounding areas are used for vineyards (30% of total agricultural area), fruit trees, and vegetables. Residues of chlorfenvinphos, banned in France since 2007 and mainly used for market gardening, were found at all stations except stations A2 and A7. The highest concentrations (0.22 μg kg−1 dw) are were found at stations A1 and A13.

Our study revealed that 15 stations are contaminated by endrin. The highest concentration of endrin was found at station A12 (3.30 μg kg−1 sediment dry weight), which is near an old WWTP. The presence of endrin may be explained by its persistence in the environment but also by the degradation of aldrin and dieldrin because all these compounds have been banned since 1994.

In relation to the environmental persistency of some pesticides, we highlighted that OCs such as endrin and DDT compounds are more easily reworked than organophosphates (i.e., chlorfenvinphos). To illustrate this, the recent ban of Chlorfenvinphos in France (2007) is best reflected by their lower concentration in the sediments. On the other hand, it can be noted that the concentration of organochlorine pesticides such as DDT and metabolites in sediment are still high more than 30 years after the ban. Fortunately, we believe there is a continuous biodegradation process in the shallow surface sediments, probably through aerobic mechanisms since we observed the occurrence of o,p′ and p,p′-DDE concomitantly with the absence of “anaerobic” DDE metabolite. Concerning lindane, recent use near A5 may explain its high concentration at this station, in contrast to its absence at other stations.

3.5 Environmental significance

Two widely used sediment quality guidelines, i.e., the effects range-low (ERL) and effects range median (ERM) as well as the threshold effects level (TEL) and probable effects level (PEL) guidelines (Long and Morgan 1990; Birch and Taylor, 2010) were applied to evaluate the possible ecotoxicological risks of the organic contaminants in the study area. The measured concentrations of PAHs, PCBs, and pesticides were compared with their ERL, ERM, TEL, and PEL values.

To be comparable with literature, ∑PAHs displayed in Table 3 are calculated on the basis of the 16 US EPA PAHs, without benzo[e]pyrene value. The contamination levels at all stations are lower than ERL values (3,500 μg kg−1dw), while the TEL values (870 μg kg−1 dw) are exceeded at 25% of the stations. The ERL guideline value represents the chemical concentration above which adverse toxicological effect can be detected. The TEL value represents the concentration below which adverse effects are expected to occur only rarely for PAHs in sediments (Burton 2002). Sediments which have concentrations between the TEL and ERL should be considered as having a potential toxicity with probable adverse effects.

Five stations (A7, A8, A10, A12, and B1) are higher than the TEL. Stations A7, A8, A10, and A12 show a clear contamination by heavy PAHs (four to five rings) which are above the TEL. For station B1, there is a clearly different contamination where by light PAHs and ERL are exceeded for Ace, Ac, and F which can be explained by the presence in the Berre lagoon by oil refineries, petrochemical, and steel industries.

Concerning PCBs, the NOAA guideline (Long and Morgan 1990) specifies ERL and the ERM relative to the ICES 7 PCB congeners. According to the latter study, 11 stations (A1, A2, A3, A4, A5, A6, A11, A12, A13, A14, and A16) are below the ERL (22.7 μg kg−1), four stations (A7, A9, A10 and A15) are between the ERL and the ERM (180 μg kg−1), and three stations (A8, B1 and B2) are higher than the ERM.

Related to the studied pesticides, the ERL and ERM only refer to dieldrin and endrin while TEL and PEL only refer to lindane (Smith et al. 1996). In this study, only three stations (A3, A10, and A14) are below the ERL of endrin (0.02 μg kg−1 dw), 13 stations (A1, A5, A6, A7, A8, A9, A11, A12, A13, A15, A16, B1, and B2) between the ERL and the ERM (45 μg kg−1 dw) and no station higher than the ERM. Dieldrin concentration at station A12 exceeded the ERL (0.02 μg kg−1 dw) and was below the ERM (8 μg kg−1 dw) for lindane concentration at station A5, which exceeded the PEL (1.38 μg kg−1 dw). The stations where organophosphorous and organochlorine compounds were detected correspond to sites close to agricultural areas and some of these compounds are present because of their persistence in the environment.

4 Conclusions

The study reveals total alkanes concentrations ranged from 563 to 5,068 μg kg−1 dw, the sum of 17 PAHs ranged from 153 to 1,311 μg kg−1 dw, the sum of seven PCBs concentrations ranged from 0.3 to 466.8 μg kg−1 dw and total pesticides concentrations ranged from 0.02 to 7.15 μg kg−1 dw. Ratios of specific n-alcanes (CPI, NAR, and TAR) and ratios of selected PAH (Ant/(Ant + Phe), Fl/(Fl + Pyr), BaA/(BaA + Chry), IPyr/(IPyr + BghiP)) suggest the sources of hydrocarbons in the sediments were generally terrigenous (biogenic) with markedly more pyrolytic rather than petrogenic. There are multiple sources of hydrocarbons in the Arc river and the Berre lagoon, linked to the specificities of the site: several industrial activities, steel and iron industries, refineries, heavy traffic of trucks and cars, and important atmospheric emissions due to the oil industry. Concerning PCBs and pesticides, Arc river and the Berre lagoon were contaminated by those pollutants even some of which have been banned for years. More specifically for pesticides, locations near from vineyards, wheat culture, and market gardening had higher concentrations of lindane, chlorfenvinphos, and chlorpyrifos, while the concentration of endrin is still high due to its persistence in the environment. In the perspectives of environmental risk assessment, the concentration of total PAHs and total PCBs in studied samples are similar to or substantially lower than those found in many other aquatic systems and significantly less than current sediment quality criteria (ERL and ERM) excepting for PCBs (A8, B1, and B2) and lindane (A5) contamination are higher than their ERM values which may indicate high potential toxicity of the sediment with probable adverse effects to the living biota.

Through this study, we evidenced multi contaminations (i.e., PAHs, PCBs, and pesticides) in most of stations with different order of magnitude, varying from no potential to probable harmful effect for the living biota. To obtain more reliable and comprehensive data, it is necessary to do more research works related to the other organic contaminants which emerging to date (e.g., endocrine disruptors compound, surfactant, etc…) including inorganic contaminant class (e.g., heavy metals) as well as ecotoxicological studies using bioassays including both organisms and molecular level.

Thus, the results of this work provide an insight related to input of organic pollutants from natural and anthropogenic sources to the studied area. The data gathered in this study can be used as a baseline reference concentration as part of a program of integrated watershed management on biodiversity, freshwater, and economic activities in the region Provence.

Acknowledgements

The authors specially thank Mr. Max Bresson and Jean François Barbion for their assistances during sampling trips. The authors would also thank Dr. Nick Marriner for his rereading of the manuscript. We also thank the anonymous reviewers for their constructive comments.

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  • Fehmi Kanzari
    • 1
    • 2
    • 3
  • Agung Dhamar Syakti
    • 1
    • 4
  • Laurence Asia
    • 1
  • Laure Malleret
    • 1
  • Gilbert Mille
    • 1
  • Bassem Jamoussi
    • 3
  • Manef Abderrabba
    • 2
  • Pierre Doumenq
    • 1
  1. 1.Université Paul Cézanne Aix–Marseille 3, ISM2, UMR 6263, équipe AD2MAix-en–Provence Cedex 4France
  2. 2.Institut Préparatoire aux Etudes Scientifiques et Techniques (99/UR/12-01), équipe Physico-chimie moléculaire IPESTTunisieFrance
  3. 3.Institut Supérieur de l’Education et de la Formation Continue (ISEFC), Directeur du Département de Physique et ChimieTunisieFrance
  4. 4.Fisheries and Marine Sciences Department-Jenderal Soedirman UniversityPurwokertoIndonesia

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