Archives of Environmental Contamination and Toxicology

, Volume 57, Issue 4, pp 631–638

Levels of Perfluorinated Chemicals in Municipal Drinking Water from Catalonia, Spain: Public Health Implications

Authors

  • Ingrid Ericson
    • Man-Technology-Environment Research Center (MTM), Department of Natural SciencesÖrebro University
    • Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV“Rovira i Virgili” University
  • Martí Nadal
    • Laboratory of Toxicology and Environmental Health, School of Medicine, IISPV“Rovira i Virgili” University
  • Esther Bigas
    • Catalan Public Health Agency, Department of HealthGeneralitat de Catalunya
  • Xavier Llebaria
    • Catalan Public Health Agency, Department of HealthGeneralitat de Catalunya
  • Bert van Bavel
    • Man-Technology-Environment Research Center (MTM), Department of Natural SciencesÖrebro University
  • Gunilla Lindström
    • Man-Technology-Environment Research Center (MTM), Department of Natural SciencesÖrebro University
Article

DOI: 10.1007/s00244-009-9375-y

Cite this article as:
Ericson, I., Domingo, J.L., Nadal, M. et al. Arch Environ Contam Toxicol (2009) 57: 631. doi:10.1007/s00244-009-9375-y

Abstract

In this study, the concentrations of 13 perfluorinated compounds (PFCs) (PFBuS, PFHxS, PFOS, THPFOS, PFHxA, PFHpA, PFOA, PFNA, PFDA, PFUnDA, PFDoDA, PFTDA, and PFOSA) were analyzed in municipal drinking water samples collected at 40 different locations from 5 different zones of Catalonia, Spain. Detection limits ranged between 0.02 (PFHxS) and 0.85 ng/L (PFOA). The most frequent compounds were PFOS and PFHxS, which were detected in 35 and 31 samples, with maximum concentrations of 58.1 and 5.30 ng/L, respectively. PFBuS, PFHxA, and PFOA were also frequently detected (29, 27, and 26 samples, respectively), with maximum levels of 69.4, 8.55, and 57.4 ng/L. In contrast, PFDoDA and PFTDA could not be detected in any sample. The most contaminated water samples were found in the Barcelona Province, whereas none of the analyzed PFCs could be detected in two samples (Banyoles and Lleida), and only one PFC could be detected in four of the samples. Assuming a human water consumption of 2 L/day, the maximum daily intake of PFOS and PFOA from municipal drinking water would be, for a subject of 70 kg of body weight, 1.7 and 1.6 ng/kg/day. This is clearly lower than the respective Tolerable Daily Intake set by the European Food Safety Authority. In all samples, PFOS and PFOA also showed lower levels than the short-term provisional health advisory limit for drinking water (200 ng PFOS/L and 400 ng PFOA/L) set by the US Environmental Protection Agency. Although PFOS and PFOA concentrations found in drinking water in Catalonia are not expected to pose human health risks, safety limits for exposure to the remaining PFCs are clearly necessary, as health-based drinking water concentration protective for lifetime exposure is set to 40 ng/L for PFOA.

Perfluorinated compounds (PFCs) are a group of chemicals that include perfluorinated carboxylates (PFCAs), perfluorinated sulfonates (PFASs), and polyfluorinated telomer alcohols and their derivatives. PFCs are environmentally persistent and have been detected in a variety of wildlife across the globe (Hart et al. 2009; Kannan et al. 2005; Sinclair et al. 2006; Stahl et al. 2009; Yeung et al. 2009). The most commonly detected PFC, perfluorooctane sulfonate (PFOS), has been discussed as a persistent and bioaccumulative substance (Conder et al. 2008). Concerns about possible toxic effects of PFCs, in general, and PFOS, in particular, date back to 1970, but only in 2000, the US Environmental Protection Agency (EPA) declared PFOS and perfluoroctanoic acid (PFOA) withdrawal to avoid environmental pollution and potential health risks. In 2002, the Organization for Economic Cooperation and Development stated that these substances were biopersistent, tended to accumulate in different tissues of living organisms, and were toxic to mammalians (OECD 2002).

In a recent review on human exposure to the most well known PFCs, PFOS and PFOA, Trudel et al. (2008) indicated that the largest portion of chronic exposure to PFOS and PFOA was probably the result from the intake of contaminated foods and drinking water, whereas consumer products (mainly impregnation sprays, treated carpets in homes, and coated-food contact materials) would only cause a minor portion of the consumer exposure to these PFCs.

Recently, we estimated the dietary intake of PFCs for various age–gender groups of a nonexposed general population from Tarragona Province (Catalonia, Spain; Ericson et al. 2008a). PFOS, PFOA, and perfluoroheptanoic acid (PFHpA) were the only PFCs that could be detected in the analyzed foodstuffs. In order to increase the knowledge on the human-exposure sources to PFCs, in a subsequent study we also estimated the intake of these compounds through drinking water (tap and bottled) by the population of Tarragona Province (Ericson et al. 2008b). In tap water, PFOS, PFOA, PFHpA, perfluorohexane sulfonate (PFHxS), and perfluorononanoic acid (PFNA) were detected. All PFC levels were notably lower in bottled water, where PFOS could not be detected in any sample. The contribution of drinking water (tap and bottled) to the human daily intake of various PFCs was compared for the first time with data from dietary intake of these PFCs. The results (Ericson et al. 2008a, 2008b) indicated that in certain cases, drinking water might be a source of exposure to PFCs as important as the dietary intake of these pollutants. It was also indicated that levels of PFCs and the PFC pattern could differ significantly between different water sources or production. Taking this into account, the aim of the present investigation was to increase the knowledge of the role of drinking water in human exposure to PFCs. In this survey, the current area of sampling covers all Catalonia.

Materials and Methods

Sample Collection

In February 2008, water samples were collected at 40 sampling points throughout Catalonia, Spain. These points were selected in accordance with the recommendations of the Catalan Agency of Public Health and included the most important supply areas in Catalonia (Fig. 1). Sampling points were assigned to five areas dividing Catalonia, which included Barcelona, Girona, Lleida, Tarragona, and Terres de l’Ebre. At each sampling point, and before collection of the respective samples, water was allowed to freely flow for 4–5 min. Duplicate water samples of 0.75 L were kept in two transparent polyethylene (PET) bottles. These bottles were previously washed five times with water of the respective sampling point. All samples were collected without direct contact between tap and bottle, avoiding the presence of air chambers within the bottle, and kept refrigerated until PFC analysis.
https://static-content.springer.com/image/art%3A10.1007%2Fs00244-009-9375-y/MediaObjects/244_2009_9375_Fig1_HTML.gif
Fig. 1

Map of 40 sampling points used for PFC analysis in tap water samples from Catalonia, Spain

Sample Extraction and Preparation

Water samples were filtered with glass microfiber filters, Whatman® (Schleicher and Schuell, Maidstone, UK), and the dissolved phase was used for analysis. Samples were concentrated using solid-phase extraction (SPE) (Ericson et al. 2008b). Briefly, 500 mL of water were used for extraction after adjusting the pH to 4 using an HCl solution. Extraction standards, 13C4-PFOS and 13C4-PFOA (Wellington Laboratories, Guelph, Ontario, Canada), were added to monitor the recovery of the sulfonates and carboxylates. After 10 min, water samples were loaded onto Waters Oasis® WAX single-use cartridges (6 cm3/150 mg) previously conditioned with 4 mL of MeOH and 4 mL of water. Vacuum was used to speed up the concentration of water samples. After drying, SPE cartridges were eluted with 4 mL of acetate buffer solution (discarded) and 2 mL of 2% NH4 in MeOH (target fraction). This fraction was filtered (2-μm nylon filter) and evaporated under nitrogen. The final volume was set to 500 μL, including 13C5-labeled PFNA added as performance standard and 300 μL of 2 mM sodium acetate (E. Merck, Darmstadt, Germany) in water.

Analytical Procedure

The levels of the 13 following PFCs were determined: perfluorobutane sulfonate (PFBuS), PFHxS, PFOS, 1H,1H,2H,2H-perfluorooctanesulfonic acid (THPFOS), perfluorohexanoic acid (PFHxA), PFHpA, PFOA, PFNA, perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), perfluorododecanoic acid (PFDoDA), perfluorotetradecanoic acid (PFTDA), and perfluorooctanesulfonamide (PFOSA). Analysis was performed using an Acquity UPLC coupled to a Quattro Premier XE tandem mass spectrometer (Waters Corporation, Milford, CT, USA) with an atmospheric electrospray interface operating in the negative ion mode (ES-MS/MS). Separation was performed on an Acquity BEH C18 (2.1 × 50 mm, 1.7 μm) kept at 50°C. An extra guard column (Waters prototype) was inserted immediately prior to the injector to remove any fluorochemicals originating from the UPLC system. The injection volume was 10 μL and the flow rate was set to 400 μL/min. A gradient program delivering the mobile phases of 2 mM ammonium acetate in methanol and 2 mM ammonium acetate in water was employed. Multiple reaction monitoring was achieved using parent ion [M] for sulfonates and [M-COOH] for carboxylates. The most abundant transition was chosen for quantification. Other transitions were used for confirmation and calculation of the identity ratio by calculating the ratio between secondary and primary transitions in the samples compared to standards. For PFOS, the 498.9 over 98.7 transition was used for quantification, whereas 413 over 369, 399 over 80, and 313 over 269 were used for the quantification of PFOA, PFHxS, and PFHxA respectively.

Quantification and Quality Assurance

Quantification of PFCs was performed using the internal standard method. Labeled 13C4-PFOS was used as an extraction standard for the sulfonates, whereas 13C4-PFOA was used for the carboxylates. The performance standard 13C5-PFNA was used to monitor the recovery of the extraction standards. Recoveries of 71–118% and 68–110% were achieved for 13C4-PFOA and 13C4-PFOS, respectively. The limit of detection (LOD) was determined as three times the signal-to-noise ratio. One blank sample [High-performance liquid chromatographic (HPLC)-grade water], one spiked water sample, and one reference water sample were extracted with every batch of samples, showing good repeatability for the method. External quality assurance was performed by successful participation (z-scores <2) in the first and second interlaboratory study on PFCs (van Leeuwen et al. 2006).

Results and Discussion

Concentrations of PFCs

Table 1 summarizes the mean and median levels of the 13 analyzed PCFs, standard deviations, minimum and maximum values, as well as the number of water samples in which the respective PFC was not detected. The compounds showing the highest mean concentrations were PFOA (4.57 ng/L) and PFBuS (4.52 ng/L), followed by PFOS (3.72 ng/L) and PFNA (2.86 ng/L). The highest and lowest median values corresponded to PFOA (0.98 ng/L) and PFOSA (0.02 ng/L), respectively, whereas the maximum and minimum individual concentrations corresponded to PFBuS (69.43 ng/L) and PFHxS (<0.02 ng/L), repectively.
Table 1

Concentrations of PFCs (ng/L) in samples of municipal drinking water collected in Catalonia: mean, SD, median, minimum and maximum values, and number of samples in which the corresponding PFC was not detected

 

Mean

SD

Median

Minimum

Maximum

No. of nondetected

PFBuS

4.52

14.48

0.36

<0.07

69.43

11

PFHxS

0.64

1.17

0.14

<0.02

5.30

9

PFOS

3.72

10.73

0.51

<0.12

58.12

5

THPFOS

0.57

1.10

0.31

<0.62

7.16

35

PFHxA

1.48

2.17

0.50

<0.17

8.55

13

PFHpA

1.82

3.58

0.24

<0.47

18.40

23

PFOA

4.57

10.03

0.98

<0.85

57.43

14

PFNA

2.86

9.82

0.19

<0.15

58.21

15

PFDA

0.52

1.64

0.06

<0.12

10.00

27

PFUnDA

0.18

0.67

0.04

<0.07

4.23

35

PFDoDA

<0.04

40

PFTDA

<0.06

40

PFOSA

0.08

0.28

0.02

<0.03

1.80

29

The individual PFC concentrations in municipal drinking water samples for each of the 40 sampling points are shown in Table 2. It must be noted that in all samples, the concentrations of PFDoDA and PFDTA were under their respective detection limits. The highest levels of the detected PFCs were found in the following municipalities: PFBuS (69.43 ng/L), PFOS (58.12 ng/L) and THPFOS (7.16 ng/L) in El Prat de Llobregat and PFHxS (5.30 ng/L) PFHxA (8.55 ng/L), PFHpA (18.40 ng/L), PFOA (57.43 ng/L), PFNA (58.21 ng/L), PFDA (10.00 ng/L), PFUnDA (4.23 ng/L), and PFOSA (1.80 ng/L) in Tordera. In general terms, the most polluted water samples were those collected in Tordera and El Prat de Llobregat, followed by those collected in Abrera, where comparatively high concentrations of PFBuS (62.66 ng/L), PFOS (29.57 ng/L), PFOA (15.44 ng/L), and PFDA (1.16 ng/L) were also found. It is interesting to note that all these municipalities belong to the Barcelona area, which is the most industrialized zone of Catalonia. In the remaining four areas, PFC levels were, on average, notably lower. The mean values of the 13 PFCs shown according to the 5 areas of Catalonia in which water samples were collected are summarized in Table 3. A considerable difference between the levels of PFCs found in the Barcelona area and those found in the remaining four areas can be noted.
Table 2

Individual concentrations of PFCs (ng/L) in municipal drinking water samples collected in 40 sampling points of Catalonia

   

PFBuS

PFHxS

PFOS

THPFOS

PFHxA

PFHpA

PFOA

PFNA

PFDA

PFUnDA

PFDoDA

PFTDA

PFOSA

1

Barcelona

Igualada

0.16

0.03

<0.12

<0.62

<0.17

<0.47

<0.85

0.85

<0.12

<0.07

<0.04

<0.06

<0.03

2

Barcelona

Calaf

0.59

0.16

0.17

<0.62

1.42

0.91

1.05

0.34

<0.12

<0.07

<0.04

<0.06

<0.03

3

Barcelona

Manresa

<0.07

0.42

0.43

<0.62

0.38

<0.47

1.03

0.31

<0.12

<0.07

<0.04

<0.06

0.09

4

Barcelona

Olost

0.68

0.41

1.04

0.94

2.96

2.75

7.51

2.00

0.19

<0.07

<0.04

<0.06

0.09

5

Barcelona

El Brull

<0.07

<0.02

0.13

<0.62

<0.17

<0.47

<0.85

<0.15

<0.12

<0.07

<0.04

<0.06

<0.03

6

Barcelona

Abrera

62.66

2.17

29.57

1.29

5.00

5.17

15.44

6.99

1.16

0.07

<0.04

<0.06

0.12

7

Barcelona

Vilafranca

5.72

3.93

1.26

<0.62

1.36

1.01

3.39

0.40

<0.12

<0.07

<0.04

<0.06

<0.03

8

Barcelona

Cardedeu

5.73

0.25

1.35

<0.62

1.08

0.70

2.52

0.71

0.44

<0.07

<0.04

<0.06

<0.03

9

Barcelona

Tordera

5.52

5.30

24.50

0.84

8.55

18.40

57.43

58.21

10.00

4.23

<0.04

<0.06

1.80

10

Barcelona

Mataró

9.97

0.82

1.40

1.52

1.51

0.91

3.07

0.42

<0.12

<0.07

<0.04

<0.06

<0.03

11

Barcelona

Palafolls

2.96

3.13

12.51

<0.62

6.90

10.11

23.89

23.17

2.53

0.65

<0.04

<0.06

0.20

12

Barcelona

Esparreguera

3.19

0.48

1.30

<0.62

3.67

6.42

8.06

0.82

<0.12

<0.07

<0.04

<0.06

0.06

13

Barcelona

Castellar del Vallés

1.21

0.18

1.10

<0.62

4.32

7.60

14.01

7.80

2.38

0.54

<0.04

<0.06

0.04

14

Barcelona

El Prat de Llobregat

69.43

2.30

58.12

7.16

5.85

4.67

15.17

6.17

1.10

0.63

<0.04

<0.06

0.06

15

Girona

Girona

<0.07

<0.02

<0.12

<0.62

<0.17

<0.47

1.24

0.27

<0.12

<0.07

<0.04

<0.06

<0.03

16

Girona

Blanes

1.44

0.29

0.77

<0.62

5.74

5.41

6.64

2.30

0.18

<0.07

<0.04

<0.06

<0.03

17

Girona

Figueres

<0.07

<0.02

0.15

<0.62

<0.17

<0.47

0.99

<0.15

<0.12

<0.07

<0.04

<0.06

<0.03

18

Girona

Olot

0.70

<0.02

<0.12

<0.62

<0.17

<0.47

<0.85

<0.15

<0.12

<0.07

<0.04

<0.06

<0.03

19

Girona

Banyoles

<0.07

<0.02

<0.12

<0.62

<0.17

<0.47

<0.85

<0.15

<0.12

<0.07

<0.04

<0.06

<0.03

20

Girona

Ripoll

4.91

0.31

1.26

<0.62

0.95

0.70

2.92

0.65

0.26

<0.07

<0.04

<0.06

0.07

21

Girona

Montgrí

0.75

0.73

3.48

<0.62

<0.17

<0.47

<0.85

<0.15

<0.12

<0.07

<0.04

<0.06

<0.03

22

Lleida

Lleida

<0.07

<0.02

<0.12

<0.62

<0.17

<0.47

<0.85

<0.15

<0.12

<0.07

<0.04

<0.06

<0.03

23

Lleida

Balaguer

<0.07

0.06

0.15

<0.62

0.20

0.52

0.85

<0.15

<0.12

<0.07

<0.04

<0.06

<0.03

24

Lleida

Tàrrega

0.16

0.15

0.33

<0.62

0.41

<0.47

0.96

0.19

<0.12

<0.07

<0.04

<0.06

<0.03

25

Lleida

Solsona

<0.07

<0.02

0.65

<0.62

<0.17

<0.47

0.85

<0.15

<0.12

<0.07

<0.04

<0.06

<0.03

26

Lleida

Cervera

0.09

0.07

0.37

<0.62

0.35

<0.47

0.96

0.16

<0.12

<0.07

<0.04

<0.06

<0.03

27

Lleida

Alcarràs

<0.07

0.06

0.64

<0.62

0.25

<0.47

1.46

0.22

0.21

<0.07

<0.04

<0.06

<0.03

28

Lleida

Tremp

0.10

0.02

0.13

<0.62

0.18

<0.47

1.25

0.20

0.18

<0.07

<0.04

<0.06

<0.03

29

Tarragona

Cunit

0.55

0.15

0.58

<0.62

1.06

0.74

1.99

0.35

0.25

<0.07

<0.04

<0.06

0.05

30

Tarragona

Sarral

<0.07

<0.02

0.12

<0.62

<0.17

<0.47

<0.85

<0.15

<0.12

<0.07

<0.04

<0.06

<0.03

31

Tarragona

Tarragona

0.24

0.07

0.23

<0.62

0.59

<0.47

<0.85

0.18

<0.12

<0.07

<0.04

<0.06

<0.03

32

Tarragona

Reus

0.37

0.12

0.25

<0.62

0.64

0.53

0.88

0.15

<0.12

<0.07

<0.04

<0.06

<0.03

33

Tarragona

Valls

0.35

0.41

0.59

<0.62

0.78

<0.47

<0.85

0.22

<0.12

<0.07

<0.04

<0.06

<0.03

34

Tarragona

El Vendrell

0.36

1.48

0.94

<0.62

0.37

<0.47

0.87

<0.15

<0.12

<0.07

<0.04

<0.06

<0.03

35

Tarragona

Cambrils

0.36

0.14

0.25

<0.62

0.81

<0.47

<0.85

<0.15

<0.12

<0.07

<0.04

<0.06

<0.03

36

Terres de l’Ebre

Tortosa

0.18

0.13

0.30

<0.62

<0.17

<0.47

<0.85

<0.15

<0.12

<0.07

<0.04

<0.06

<0.03

37

Terres de l’Ebre

Amposta

<0.07

<0.02

0.38

<0.62

<0.17

<0.47

<0.85

<0.15

<0.12

<0.07

<0.04

<0.06

<0.03

38

Terres de l’Ebre

Móra d’Ebre

0.46

0.55

1.31

<0.62

<0.17

<0.47

<0.85

<0.15

<0.12

<0.07

<0.04

<0.06

<0.03

39

Terres de l’Ebre

Flix

1.28

1.00

2.39

<0.62

2.08

0.77

2.38

0.19

0.27

<0.07

<0.04

<0.06

0.09

40

Terres de l’Ebre

L’Aldea

0.28

0.07

0.20

<0.62

0.68

<0.47

<0.85

<0.15

<0.12

<0.07

<0.04

<0.06

<0.03

Detection limit

  

<0.07

<0.02

<0.12

<0.62

<0.17

<0.47

<0.85

<0.15

<0.12

<0.07

<0.04

<0.06

<0.03

Table 3

Mean concentrations of PFCs (ng/L) in samples of municipal drinking water given according to five zones of Catalonia

 

Barcelona

Girona

Lleida

Tarragona

Terres de l’Ebre

PFBuS

11.99

1.13

0.07

0.32

0.45

PFHxS

1.39

0.20

0.05

0.34

0.35

PFOS

9.50

0.84

0.33

0.42

0.92

THPFOS

1.04

ND

ND

ND

ND

PFHxA

3.08

1.02

0.22

0.62

0.60

PFHpA

4.24

1.04

0.28

0.35

0.34

PFOA

10.96

1.87

0.97

0.78

0.82

PFNA

7.73

0.50

0.14

0.16

0.10

PFDA

1.30

0.11

0.10

ND

0.10

PFUnDA

0.46

ND

ND

ND

ND

PFDoDA

ND

ND

ND

ND

ND

PFTDA

ND

ND

ND

ND

ND

PFOSA

0.18

ND

ND

ND

0.03

ND Not detected

A principal component analysis (PCA) of the PFC concentrations in water samples from 40 locations of Catalonia was conducted. PCA has become an extensively used methodology in environmental studies due to its capacity to deal with large datasets (Wold et al. 1985). The PCA score plot, showing the relation between the sampling points, is depicted in Fig. 2. Principal component 1 (PC1) explained 49% of the variance in the dataset, whereas PC2 explained another 24%. The loading plot of PC1 versus PC2 is shown in Fig. 3. In total, five principal components were significant according to cross-validation. PCA clearly showed a difference in PFC pattern of several samples from the Barcelona area (B6–B8, B10, B14) and one sample from the Girona area (G20). This difference was mainly due to PFBuS (Fig. 3). A closer investigation of these sampling points showed that these five Barcelona samples originated from the same water supplier.
https://static-content.springer.com/image/art%3A10.1007%2Fs00244-009-9375-y/MediaObjects/244_2009_9375_Fig2_HTML.gif
Fig. 2

Score plot of PCA

https://static-content.springer.com/image/art%3A10.1007%2Fs00244-009-9375-y/MediaObjects/244_2009_9375_Fig3_HTML.gif
Fig. 3

Loading plot of PC1 versus PC2

Data concerning PFC levels in drinking water is rather limited. In a recent review, Fromme et al. (2009) indicated that PFC concentrations in water were in the low nanogram per liter range if there was no large point source of PFCs to the drinking water source. The results of the current study are all in this rather low nanogram per liter range, being in agreement with recent data from Germany (Lange et al. 2007) and Japan (Saito et al. 2004). The reported PFOS levels varied between 5.4 and 40.0 ng/L and between <0.1 and 0.2 ng/L in drinking water from exposed areas or from areas with no known sources, respectively. For PFOA, concentrations were found in the range 1.1–1.6 and 0.1–0.7 ng/L, respectively. Recently, Takagi et al. (2008) measured the levels of PFOS and PFOA in raw and potable tap water collected from 14 water-treatment plants in Osaka, Japan. Concentration ranges of PFOS and PFOA in potable tap water were 0.16–22 ng/L and 2.3–84 ng/L, respectively, levels that are of similar or higher magnitude than those found in the current study, ranging between 0.06 and 58.1 ng/L for PFOS and between 0.43 and 57.4 ng/L for PFOA. In turn, Tanaka et al. (2008) determined the concentrations of these two same PFCs in tap water from 21 cities belonging to 10 Asian countries. PFOS levels were in the range from 0.01 to 143.1 ng/L, whereas levels of PFOA were in the range from 0.01 to 86.9 ng/L.

In Germany, Skutlarek et al. (2006) determined the levels of PFCs in drinking water samples collected in public buildings of the Rhine-Ruhr area. The maximum concentration of all drinking water samples taken in the Rhine-Ruhr area was 598 ng/L, PFOA being the major component (519 ng/L). In the present study, the highest PFOA level (57.43 ng/L) was about 10-fold lower than that concentration. In May 2006 the first serious German PFC case of contamination became evident. Industrial waste with high concentrations of PFCs was manufactured into a soil improver by a recycling company and spread by farmers on agricultural land of the rural area of Sauerland and led to substantial environmental pollution (Wilhelm et al. 2008). Of the various PFCs analyzed, PFOA was the main compound found in drinking water, with concentrations in parts of the affected area higher than 0.5 μg/L (500-640 ng/L). PFC concentrations in plasma of children and adults exposed to that PFC-contaminated drinking water increased fourfold to eightfold compared with controls (Hölzer et al. 2008). Considering a 100:1 ratio of drinking water contribution to serum levels (Post et al. 2009), a drinking water concentration of 4.57 ng/L (aritmethic mean for PFOA) would result in a serum level of PFOA of 0.46 ng/mL or 0.91 ng/mL on a whole-blood basis. With a total PFOA level of 1.80 ng/mL in blood of the Catalan population (Ericson et al. 2007), the contribution of drinking water to the total intake of PFOA might be considered as substantial.

Recently (Ericson et al. 2008b), we determined the levels of PFOS, PFOA, and other PFCs in drinking water (tap and bottled) samples from Tarragona Province (Catalonia). In tap water, PFOS and PFOA levels ranged between 0.39 and 0.87 ng/L and between 0.32 and 6.28 ng/L, respectively. In the current study, the mean PFOS and PFOA levels found in the Tarragona area agree quite well with our previous results. PFHpA, PFHxS, and PFNA were also detected. PFC levels were notably lower in bottled water, and PFOS was not detected in any sample of the four commercial trademarks analyzed (Ericson et al. 2008b).

Estimates of PFC Intake Through Drinking Water and Health Risks

In a worst-case scenario exposure and assuming an intake of 2 L of tap water per day by the general population of Catalonia, the highest exposure to PFCs through drinking water would correspond to the following compounds: PFBuS and PFOS for individuals from El Prat de Llobregat, with intakes of 138.9 and 116.2 ng/day, respectively, and PFOA, PFNA, and PFHpA for subjects from Tordera, with intakes of 114.9, 116.4, and 36.8 ng/day, respectively. In a recent study, the dietary intake of a number of PFCs was determined for the population of Tarragona County (Catalonia) (Ericson et al. 2008a). PFC levels were measured in 36 composite samples of foodstuffs randomly purchased in various locations. In contrast to the results of the current study, where most PFCs could be detected in water samples, PFOS, PFOA, and PFHpA were the only detected PFCs in foodstuffs. Whereas PFOS was found in a number of analyzed food items, PFOA and PFHpA were only detected in milk samples (Ericson et al. 2008b). On average, for an adult man of 70 kg of body weight, the dietary intake of PFOS was estimated to be 62.5 ng/day (assuming Not Detected = 1/2 LOD). This value is approximately half of the PFOS intake through drinking water in the worst-case scenario (116.2 ng/day). It was concluded that in Catalonia, at least for PFOS, tap water can be a source of exposure to this pollutant even more important than its dietary intake.

Oral reference dose (RfD) values for most PFCs have not been yet established by any government or regulatory agency. However, provisional RfDs for PFOS and PFOA have been estimated on the basis of a rat chronic carcinogenicity study and a rat multigenerational study, respectively (Gulkowska et al. 2006). On this basis, the provisional RfDs would be 25 and 333 ng/kg/day for PFOS and PFOA, respectively. Therefore, for an adult of 70 kg body weight, the intakes through tap water of PFOS (1.7 ng/kg/day) and PFOA (1.6 ng/kg/day) would be considerably lower than the provisional RfD values for PFOS and PFOA. Even summing drinking water together with the dietary intake of these compounds, the safety margin is still not exceeded. Recently, the European Food Safety Authority (EFSA 2008) recommended tolerable daily intakes (TDIs) for PFOS and PFOA of 150 and 1,500 ng/kg/day, respectively, values notably higher than the suggested provisional RFDs.

Specifically for drinking water, for guidance purposes, the 3 M Company, the main manufacturer of PFOS, developed a lifetime Drinking Water Health Advisory (DWHA), which was estimated to be 1,000 ng PFOS/L (assuming a consumption of 2 L per day of contaminated water) (3M 2001), a value that, according to experimental studies in primates, would not represent imminent health risks (Hansen et al. 2002). However, in a recent study on PFOA in drinking water systems, the contribution of drinking water to human exposure to PFOA was evaluated and a health-based drinking water concentration protective for lifetime exposure of 40 ng/L was developed through a risk assessment approach (Post et al. 2009). In one sample from Tordera (57.4 ng/L), the health-based concentration is exceeded by 17 ng/L, which might pose concern for human health. In addition to its use for drinking, potable water might be used for washing of fruits and vegetables as well as in cooking processes such as boiling and might thus also be included when estimating human exposure to PFCs from drinking water. The health-based concentration of 40 ng/L is one-tenth of the provisional health advisory developed by the US EPA (USEPA 2009) for PFOA (400 ng/L). For PFOS, the US EPA provisional health advisory is 200 ng/L (USEPA 2009). Due to the differences in health-based concentrations for humans and the measured levels in the current and others studies, further research is needed for complete risk assessment of human exposure to perfluorinated compounds.

Conclusions

The results of this study show that, in general terms, the concentrations of the 13 analyzed PFCs, including PFOS and PFOA, in potable tap water from Catalonia, are of similar magnitude or somewhat lower than those recently found in other international surveys. The highest PFC levels were observed in municipalities of Barcelona, which is the zone of Catalonia with the greatest industrial activity. Although the concentrations of PFOS and PFOA, the most well-known PFCs, found in drinking water from Catalonia are not expected to pose human health risks, information on safety limits for exposure to the remaining PFCs is not currently available. Consequently, in order to protect human health, this information is clearly necessary for guidance purposes.

Acknowledgment

This study was financially supported by the Catalan Public Health Agency, Department of Health, Generalitat de Catalunya, Barcelona, Catalonia, Spain.

Copyright information

© Springer Science+Business Media, LLC 2009