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Pan-European survey on the occurrence of selected polarorganic persistent pollutants in ground water
Robert Loos a,*, Giovanni Locoro a, Sara Comero a, Serafino Contini a,1, David Schwesig b,Friedrich Werres b, Peter Balsaa b, Oliver Gans c, Stefan Weiss c, Ludek Blaha d,Monica Bolchi e, Bernd Manfred Gawlik a
aEuropean Commission, Joint Research Centre, Institute for Environment and Sustainability, Via Enrico Fermi, 21020 Ispra, Italyb IWW Water Centre, Moritzstr. 26, 45476 Muelheim an der Ruhr, GermanycUmweltbundesamt GmbH, Spittelauer Lande 5, 1090 Vienna, AustriadMasaryk University, RECETOX, Kamenice 3, CZ 62500 Brno, Czech Republice Perkin Elmer Italia S.p.A., Via Tiepolo, 24, I 20052 Monza (MI), Italy
a r t i c l e i n f o
Article history:
Received 9 February 2010
Received in revised form
17 May 2010
Accepted 22 May 2010
Available online 1 June 2010
Keywords:
Ground water
Pan-European monitoring
Non-probabilistic sampling
Polar organic contaminants
SPE-LC-MS2
* Corresponding author. Tel.: þ39 0332 78640E-mail address: [email protected]
1 In remembrance of Serafino Contino.0043-1354/$ e see front matter ª 2010 Elsevdoi:10.1016/j.watres.2010.05.032
a b s t r a c t
This studyprovides thefirst pan-European reconnaissance of the occurrence of polar organic
persistent pollutants in European ground water. In total, 164 individual ground-water
samples from 23 European Countries were collected and analysed (among others) for 59
selected organic compounds, comprising pharmaceuticals, antibiotics, pesticides (and their
transformation products), perfluorinated acids (PFAs), benzotriazoles, hormones, alkylphe-
nolics (endocrine disrupters), Caffeine, Diethyltoluamide (DEET), and Triclosan. The most
relevant compounds in terms of frequency of detection and maximum concentrations
detected were DEET (84%; 454 ng/L), Caffeine (83%; 189 ng/L), PFOA (66%; 39 ng/L), Atrazine
(56%; 253 ng/L), Desethylatrazine (55%; 487 ng/L), 1H-Benzotriazole (53%; 1032 ng/L), Meth-
ylbenzotriazole (52%; 516 ng/L), Desethylterbutylazine (49%; 266 ng/L), PFOS (48%, 135 ng/L),
Simazine (43%; 127 ng/L), Carbamazepine (42%; 390 ng/L), nonylphenoxy acetic acid (NPE1C)
(42%; 11 mg/L), Bisphenol A (40%; 2.3 mg/L), PFHxS (35%; 19ng/L), Terbutylazine (34%; 716 ng/L),
Bentazone (32%; 11 mg/L), Propazine (32%; 25 ng/L), PFHpA (30%; 21 ng/L), 2,4-Dinitrophenol
(29%; 122 ng/L), Diuron (29%; 279 ng/L), and Sulfamethoxazole (24%; 38 ng/L). The chemicals
whichwere detectedmost frequently above the European groundwater quality standard for
pesticides of 0.1 mg/Lwere Chloridazon-desphenyl (26 samples), NPE1C (20), Bisphenol A (12),
Benzotriazole (8), N,N0-Dimethylsulfamid (DMS) (8), Desethylatrazine (6), Nonylphenol (6),
Chloridazon-methyldesphenyl (6), Methylbenzotriazole (5), Carbamazepine (4), and Benta-
zone (4). However, only 1.7% of all single analyticalmeasurements (in totale8000) were above
this threshold value of 0.1 mg/L; 7.3% were > than 10 ng/L.
ª 2010 Elsevier Ltd. All rights reserved.
1. Introduction the world. Ground water is the most sensitive and the largest
The growing scarcity of water resources is one of the most
critical environmental problems facing us in many regions of
7; fax: þ39 0332 786351..eu (R. Loos).
ier Ltd. All rights reserved
body of freshwater in the European Union (EU) and, in
particular, also a main source of public drinking water
supplies in many regions. The EU Ground water Directive
.
wat e r r e s e a r c h 4 4 ( 2 0 1 0 ) 4 1 1 5e4 1 2 64116
(GWD) 2006/118/EC on the protection of ground water against
chemical pollution and deterioration (EC, 2006) developed
under Article 17 of the Water Framework Directive (WFD) (EC,
2000) sets out criteria for the assessment of the chemical
status of ground water. This Directive is based on existing
Community quality standards (nitrates, pesticides and
biocides) and on the requirement for Member States to iden-
tify pollutants and threshold values that are representative of
groundwater bodies found as being at risk, in accordancewith
the analysis of pressures and impacts carried out under the
WFD (EC, 2000, 2006).
The quality of ground water, as far as the pesticides
content is concerned, has been traditionally assessed in the
EU in respect to the Drinking Water Directive 98/83/EC (EC,
1998), which establishes the quality criteria of water inten-
ded for human consumption, since this is one of the most
sensitive uses of groundwater. This directive sets amaximum
concentration of 0.1 mg/L for individual pesticides and their
degradation products, and 0.5 mg/L for total pesticides present
in a sample. These values are identical to the ground water
quality standards of the GWD (EC, 2006).
In general, ground water is contaminated by sewage
wastewaters through leakage from decrepit sewer pipes, the
past practice of sewage infiltration to underground, leakages
on industrial sites or animal farms, through application of
sewage sludge from municipal waste water treatment plants
(WWTPs) on agricultural fields, urban and rural storm water
runoff, infiltration by contaminated river water, and inten-
tional application of pesticides or artificial fertilizers onto soils
(Dıaz-Cruz and Barcelo, 2008).
In the year 2000, the US Geological Survey performed
a national reconnaissance of pharmaceuticals and other
organic waste water contaminants in ground and drinking
water sources (Barnes et al., 2008; Focazio et al., 2008). In this
study, water samples were collected from a network of 47
ground water sites across 18 US States, and 65 organic
compounds were analysed. The most frequently detected
compoundswere DEET (Diethyltoluamide), an insect repellant
(frequency of detection 35%), Bisphenol A (30%), Tri(2-chlor-
oethyl)-phosphate (30%, fire retardant), Sulfamethoxazole
(23%, veterinary and human antibiotic), Carbamazepine (20%),
Tetrachloroethylene (24%, solvent), 1,7-Dimethylxanthine
(16%; caffeine metabolite), and 4-Octylphenol mono-
ethoxylate (19%). Pesticides were identified before as common
contaminants in shallow ground water (Kolpin et al., 1998),
having been found at 54% of 1034 sites sampled in agricultural
and urban settings across the United States. Of the 46 pesti-
cide compounds examined, 39 were detected, and the most
frequently detected compounds were Atrazine (38%), Dese-
thylatrazine (34%), Simazine (18%), Metolachlor (15%), and
Prometon (14%).
In Europe, the chemical monitoring of ground water has
received somewhat less attention compared to surface
waters, and comprehensive monitoring surveys are urgently
necessary. Few local studies however proved that persistent
micropollutants like carbamazepine or clofibric acid may
enter the ground water nearly un-attenuated by bank filtra-
tion of affected surface waters or by infiltration or artificial
recharge of treated wastewater into ground water (Heberer
et al., 2004; Clara et al., 2004).
The presence of pesticides in European ground waters has
been reported (in the scientific literature) in Greece
(Papastergiou and Papadopoulou-Mourkidou, 2001;
Papadopoulou-Mourkidou et al., 2004), Italy (Guzzella et al.,
2006), Portugal (Goncalves et al., 2007), and Spain
(Hildebrandt et al., 2008; Rodriguez-Mozaz et al., 2004). Liter-
ature published by national environmental agencies provides
more knowledge about the occurrence of pesticides or phar-
maceuticals in ground water (Hanke et al., 2007; BAFU, 2009).
Pharmaceutical compounds were found in ground waters
from Austria (Clara et al., 2004), Germany (Heberer and Stan,
1997; Heberer et al., 1998; Heberer, 2002; Redderson et al.,
2002; Osenbruck et al., 2007; Sacher et al., 2001; Ternes et al.,
2007), and France (Bruchet et al., 2005; Rabiet et al., 2006).
The pharmaceuticals most frequently and at the highest
concentration levels found were Carbamazepine (Clara et al.,
2004; Heberer et al., 2004; Osenbruck et al., 2007; Rabiet et al.,
2006; Sacher et al., 2001; Ternes et al., 2007), Diclofenac
(Heberer and Stan, 1997; Heberer et al., 1998; Heberer, 2002;
Redderson et al., 2002; Rabiet et al., 2006; Sacher et al., 2001),
Ibuprofen (Heberer and Stan, 1997; Heberer et al., 1998;
Heberer, 2002; Redderson et al., 2002; Rabiet et al., 2006),
Ketoprofen (Heberer and Stan, 1997; Heberer et al., 1998;
Heberer, 2002; Redderson et al., 2002; Rabiet et al., 2006),
Naproxen (Rabiet et al., 2006), Clofibric acid, Fenofibrate,
Gemfibrozil, N-(phenylsulfonyl)-sarcosine, Propyphenazone
(Heberer and Stan, 1997; Heberer et al., 1998; Heberer, 2002;
Redderson et al., 2002), Caffeine, Paracetamol (Rabiet et al.,
2006), Sotalol, Phenazone, Iopamidol, Amidotrizoic acid,
Anhydro-erythromicin, Sulfamethoxazole (Sacher et al., 2001;
Ternes et al., 2007), and X-ray contrast agents (Bruchet et al.,
2005; Ternes and Hirsch, 2000; Ternes et al., 2007).
Bisphenol A and Nonylphenol have been reported to be
frequent industrial ground water pollutants in Austria
(Hohenblum et al., 2004), Germany (Osenbruck et al., 2007;
Reinstorf et al., 2008), and Spain (Latorre et al., 2003).
Due to the apparent lack of a representative European
overview on the occurrence of organic micropollutants in
ground water, the Joint Research Centre’s Institute for Envi-
ronment and Sustainability (JRC-IES) organized a pan-Euro-
pean survey on the occurrence of selected polar organic
pollutants in European groundwaters. Fig. 1 displays a map of
the investigated ground water sampling sites.
2. Materials and methods
2.1. Sampling and transport
The investigated ground water monitoring stations were
proposed upon invitation by the individual participating EU
Member State laboratories (see acknowledgments) and finally
selected by the JRC. It is important to mention that there were
no strict selection criteria for the sampling sites such as
“representative” or “contaminated”; most monitoring
stations, however were “official” monitoring stations also
used for drinking water abstraction. The sampling was then
synchronized in a time window of 8 weeks in autumn 2008.
Sampling was performed by the participants using pre-
cleaned and conditioned sample containers provided by the
Fig. 1 e European map of the ground water monitoring sites. Note that some coordinates from Austria and Poland are
missing.
wat e r r e s e a r c h 4 4 ( 2 0 1 0 ) 4 1 1 5e4 1 2 6 4117
JRC. Upon sampling, the samples were dispatched under
cooled conditions (4 �C in cooling boxes) within 48h to the JRC
Ispra Site (Italy) for further processing. In total, 164 European
ground water sampling stations were screened, giving a rela-
tively good spatial overviewon the occurrence of polar organic
chemicals in European ground water. It must be noted,
however, that the results of this exercise cannot be seen as
a statement of the ground water quality in the Member States
or as a characterization of a single sampling station. The
campaign reflects more a comprehensive picture (“snapshot”)
of typical ground water scenarios in Europe and the data are
hence useful to draw a baseline for comparison and bench-
marking purposes. By asking Member States for support, we
are following a non-probabilistic approach, which may intro-
duce on a national level a strong bias. Thus for instance, the
map in Fig. 1 shows that several regions (e.g. Germany, France,
and Spain) were strongly under-represented. On average, i.e.
at a continental scale, however a good sample pool for the
European situation was obtained. All results described here-
after refer to the samples shipped to the facilities of the JRC’
IES-Laboratory and analysed by the same laboratory bymeans
of SPE-LC-MS2.
Methanol pre-cleaned 1 L PE or PP plastic bottles were
provided to all laboratories and sampling teams. The partici-
pants were asked to fill these bottles, leaving a small air head-
space, and storing them in a fridge atw 4 �C before dispatch by
fast courier to Ispra (Italy). The samples were shipped cooled
with freezing elements in styrofoam boxes, arrived within
48 h, and were extracted within two weeks after sampling.
Intermediate storage between the time of arrival and extrac-
tion was done at 4 �C using a laboratory refrigerator.
2.2. Solid-phase extraction (SPE)
The water samples were extracted at the JRC by solid-phase
extraction (SPE) with Oasis� HLB (200 mg) cartridges. The
water was not filtered, but decanted into a 1 L glass bottle
(Schott-Duran). Before extraction, the samples (1 L) were
spiked with the internal standard (50 mL), which contained the
labeled substances PFOA 13C4, PFOS 13C4, PFNA 13C5,
wat e r r e s e a r c h 4 4 ( 2 0 1 0 ) 4 1 1 5e4 1 2 64118
Carbamazepine d10, Simazine 13C3, Atrazine13C3, Ibuprofen
13C3, Nonylphenol 13C6, Octylphenol 13C6, Estrone d2, 2,4-D d3,
MCPA d3, and Triclosan 13C12. The spiking level in the water
samples was 5 ng/L for PFOA 13C4, PFOS 13C4, PFNA 13C5, Octyl-
and Nonylphenol 13C6, and 50 ng/L for the other labeled
compounds. The glass bottles were closed, and then the
samples were mixed by shaking.
The SPE procedure for the clean-up and concentration of
water samples was performed automatically using an
AutoTraceª SPE workstation (Caliper Life Sciences). 200 mg
(6mL) Oasis� HLB columns (Waters) were used. The cartridges
were activated and conditioned with 5 mLmethanol and 5 mL
water at a flow-rate of 5 mL/min. The water samples (950 mL;
50 mL was pumped through the tubes before for cleaning)
were passed through the wet cartridges at a flow-rate of 5 mL/
min, the columns rinsedwith 2mLwater (flow 3mL/min), and
the cartridges dried for 30 min using nitrogen at 0.6 bar.
Elution was performed with 6 mL methanol. Evaporation of
the extracts with nitrogen to 500 mL was performed at
a temperature of 35 �C in a water bath using a TurboVapª II
Concentration Workstation (Caliper Life Sciences).
2.3. Liquid chromatography tandem mass spectrometry(LC-MS2)
Analyses were performed by reversed-phase liquid chroma-
tography (RP-LC) followedbyelectrospray ionization (ESI)mass
spectrometry (MS) detection using atmospheric-pressure
ionization (API) with a triple-quadrupole MSeMS system (Agi-
lent 1100 HPLC and Waters Quattro Micro MSeMS). Quantita-
tive LC-MS2 analysis was performed in three separate LC-MS2
runs (methods 1-3) in the multiple reaction monitoring (MRM)
mode. Method 1 comprised the compounds in the negative
ionization mode, method 2 those in the positive ionization
mode, and method 3 alkylphenolic compounds and estrogens
whichwereanalysedwithadifferentHPLCmobile phase.More
analytical details can be found in Loos et al. (2007, 2008a, 2009).
2.4. Direct injection UPLC-MS/MS
Due to the polarity of certain pesticide degradation products
(e.g. DMS), conventional sample preparation methods such as
solid-phase extraction (SPE) and liquideliquid extraction (LLE)
are not applicable. Therefore, direct injection of samples in
a UPLC-ESI-MS/MS system was performed for the analysis of
DMS, Chloridazon-desphenyl and Chloridazon-methylde-
sphenyl. Calibration was done by internal standardization
using deuterium labeled DMS d6 and15N2 labeled metabolites
(Kowal et al., 2009). All experiments were carried out on
a Waters Acquity UPLC� ultra performance liquid chroma-
tography coupled with an electrospray ionization tandem
mass spectrometric system TQD-MS/MS (Waters, Milford,
USA). The UPLC columns HSS C18 2.1 � 100 mm (for DMS) and
BEH Shield C18 2.1� 50mmwere used (Waters). Particle size of
both column types were 1.8 mm. Detection was in the positive
ESI-MS mode. The m/z values of the precursor ions, product
ions, and the collision-induced dissociation (CID) energy for
the quantification transitions in the multiple reaction moni-
toring (MRM) mode are listed in Table S1.
2.5. Selection of the target compounds
Pharmaceuticals and pesticides selected are among the most
commonly used substances inmedicine and agriculture. They
were identical to the chemicals studied before in our EU-wide
monitoring survey on surface waters (Loos et al., 2009). Some
additional compounds, mainly pesticides, were added to this
ground water exercise. Focus was given to (relatively)
persistent chemicals, in order to study their environmental
behavior and fate, i.e. their infiltration potential into ground
water. DEET (Diethyltoluamide) (Costanzo et al., 2007) was
included in this survey because it was in US ground water the
most frequently detected compound (Barnes et al., 2008). N,
N0-Dimethylsulfamid (DMS), Chloridazon-desphenyl, and
Chloridazon-methyldesphenyl were analysed by IWW Water
Centre in Germany, because these herbicide metabolites have
been found in German ground waters (Buttiglieri et al., 2009;
Kowal et al., 2009).
2.6. Analytical quality control
Analytical quality control measures were described before
(Loos et al., 2009). The absolute recoveries for the chemicals
including the internal standards were determined with spike
experiments in the concentration range of 10 and 100 ng/L
using Milli-Q water (replication n ¼ 6); they were in the range
of 50e90%. The limits of detection (LODs) for the SPE-LC-MS2
procedure were calculated from the mean concentration of
the blank of real water samples plus three times the standard
deviation. The measurement uncertainty is estimated to be
around 25e50%. The analytical details are given in Table S1. In
addition, in 2009 we participated in the 3rd interlaboratory
study on perfluorinated compounds in water, fish, and sludge
(organized by Stefan van Leeuwen, Institute for Environ-
mental Studies (IVM), VU University Amsterdam, NL). More-
over, the samples from Austria were cross-checked by
Umweltbundesamt Vienna for some compounds such as
Bentazone, Atrazine, Terbutylazine, and Sulfamethoxazole.
3. Results and discussion
3.1. SPE-LC-MS2 analysis of the target compounds
The analytical details (MRM transitions, MS parameters,
retention times, recoveries, and LODs ¼ reporting limits) for
the polar organic chemicals investigated in this study are
given in Table S1 (supporting information). Fig. 2 shows
exemplary LC-MS2 chromatograms of two impacted ground
water samples in positive (A) and negative (B) ionization
modes, demonstrating that in these samples benzotriazoles,
different pesticides and their degradation products, Sulfa-
methoxazole, Carbamazepine, perfluorinated acids (PFAs),
Mecoprop and Diclofenac were detected.
3.2. Chemical compounds identified
A summary of the analytical results for the polar organic
chemicals measured in the 164 ground water samples
across Europe is given in Table 1. In total 59 different
Fig. 2 e MRM-LC-MS2 chromatograms of two impacted ground water samples. Positive (A) and negative (B) ionization
modes; Hypersil Gold column 100 3 2.1 mm, 3 mm particles; eluants: water (0.1% acetic acid) and acetonitrile; gradient start
with 90% water; flow-rate 250 ml/min.
wat e r r e s e a r c h 4 4 ( 2 0 1 0 ) 4 1 1 5e4 1 2 6 4119
organic chemical compounds were analysed. The maximum
number of compounds detected at any site was 29, and the
median number of detections per site was 12. There was no
sample free of organic chemicals; in five samples only 3
compounds were found. However, it should be noted that
the reporting limit (¼LOD) was in the low ng/L range for
most chemicals.
3.3. Frequency of detection and maximumconcentrations
The compounds in Table 1 are sorted by their frequency of
detection. The most frequently detected compounds were
DEET, Caffeine, PFOA, Atrazine, Desethylatrazine, 1H-Benzo-
triazole, Methylbenzotriazole, Desethylterbutylazine, PFOS,
Table 1 e Summary of analytical results for polar organic pollutants in EU ground waters.
Chemical LOD [ng/L] Freq [%] max [ng/L] Average [ng/L] med [ng/L] Per90 [ng/L]
DEET 0.4 83.5 454 9 1 9
Caffeine 1.0 82.9 189 13 4 32
PFOA 0.4 65.9 39 3 1 6
Atrazine 0.4 56.1 253 8 1 24
Desethylatrazine (DEA) 0.4 54.9 487 17 1 50
1H-Benzotriazole 1.0 53.0 1032 24 1 40
Methylbenzotriazole 1.0 51.8 516 20 4 42
Desethylterbutylazine (DET) 0.4 49.4 266 7 0 12
PFOS 0.4 48.2 135 4 0 11
Simazine 0.5 43.3 127 7 0 17
Carbamazepine 0.5 42.1 390 12 0 20
NPE1C 0.5 41.5 11 316 263 0 127
Bisphenol A 1.0 39.6 2299 79 0 73
PFHxS 0.4 34.8 19 1 0 5
Terbutylazine 0.3 33.5 716 6 0 2
Bentazone 0.4 31.7 10 550 116 0 15
Propazine 0.3 31.7 25 1 0 2
PFHpA 0.4 29.9 21 1 0 1
2,4-Dinitrophenol 1.0 29.3 122 4 0 6
Diuron 0.3 28.7 279 3 0 3
Sulfamethoxazole 0.5 24.4 38 2 0 4
PFDA 0.4 23.8 11 0 0 1
tert-Octylphenol (OP) 0.4 23.2 41 1 0 2
Metolachlor 0.3 20.7 209 2 0 2
Nitrophenol 4.0 20.1 152 4 0 8
Isoproturon 0.2 20.1 22 0 0 0
Hexazinone 0.3 17.7 589 4 0 1
Chloridazon-desphenyl 50 16.5 13 000 176.9 0 217
PFBS 0.3 15.2 25 0 0 1
PFNA 0.4 15.2 10 0 0 0
Mecoprop 0.2 13.4 785 7 0 1
N,N’-Dimethylsulfamid (DMS) 50 11.6 52 000 332 0 50
Nonylphenol (NP) 30.0 11.0 3850 83 0 39
Ketoprofen 1.0 10.4 2886 26 0 2
Diazinon 0.3 9.1 1 0 0 0
MCPA 0.1 7.9 36 0 0 0
Chlortoluron 0.3 7.9 91 1 0 0
Ibuprofen 0.2 6.7 395 3 0 0
Chloridazon-methyldesphenyl 50 6.1 1200 19.1 0 0
Methabenzthiazuron 0.3 5.5 104 1 0 0
Dichlorprop 0.1 4.9 3199 36 0 0
Diclofenac 0.2 4.9 24 0 0 0
Alachlor 0.3 4.9 27 0 0 0
2,4-D 0.1 3.7 12 0 0 0
2,4,5-T 0.2 3.7 3 0 0 0
Linuron 0.3 2.4 293 2 0 0
Triclosan 2.0 1.8 9 0 0 0
Estrone 1.0 0.6 4 0 0 0
Number of samples, 164; LOD ¼ limit of detection; freq ¼ frequency of detection [%]; max ¼ maximum concentration; med ¼ median
concentration; Per90¼ 90th percentile [%]; priority compounds of theWFD in blue. In green: Pesticidemetabolites analysed by IWWWater centre
(Germany). (For interpretation of the references to colour in this Table legend, the reader is referred to the web version of this article).
Not included are Naproxen, Propanil, Fenarimol, Bezafibrate, Gemfibrozil, PFHxA, PFUnA, Metoxuron, Carbaryl, and Molinate which were not
detected.
wat e r r e s e a r c h 4 4 ( 2 0 1 0 ) 4 1 1 5e4 1 2 64120
Simazine, Carbamazepine, NPE1C, Bisphenol A, PFHxS, Ter-
butylazine, Bentazone, Propazine, PFHpA, 2,4-Dinitrophenol,
Diuron, and Sulfamethoxazole.
The average frequency of detection for all compounds was
25%. A comparison with the results from the surface water
campaign (Loos et al., 2009), where the average frequency of
detection was 61%, shows a higher chemical contamination of
surface water in comparison to ground water.
Some compounds were found at high concentration levels
in the mg/L range. These chemicals detected at the highest
single concentration levels were N,N0-Dimethylsulfamid
(DMS) (52 mg/L; in one sample), Chloridazon-desphenyl (13 mg/
L), NPE1C (11 mg/L), Bentazone (11 mg/L), Nonylphenol (3.8 mg/L),
Dichlorprop (3.2 mg/L), Ketoprofen (2.9 mg/L), Bisphenol A
(2.3 mg/L), and 1H-Benzotriazole (1.0 mg/L) (see boxeplot
diagrams in Fig. 3).
Fig. 3 e Box-plot diagrams for the target compounds. Not
included are DMS (max. 52 mg/L in one sample; freq. 12%),
Chloridazon-desphenyl (max. 13 mg/L; freq. 17%),
Chloridazon-methyldesphenyl (max. 1.2 mg/L; freq. 6%) due
to their higher LODs of 50 ng/L; BTA [ Benzotriazole,
wat e r r e s e a r c h 4 4 ( 2 0 1 0 ) 4 1 1 5e4 1 2 6 4121
Fig. 3 shows boxeplot diagrams of the analytical results of
all ground water samples. The chemicals are sorted in three
groups according to their maximum concentration levels
detected. The chemicals with the highest concentrations
measured are not necessarily among the most frequently
detected compounds. For example, although several
compounds such as Nonylphenol, Dichlorprop, Ketoprofen,
DMS, and Chloridazon-desphenyl were detected infrequently,
they had single maximum concentrations which exceeded
1 mg/L (Table 1; Fig. 3). However, it should be noted that the
frequency of detection of DMS and Chloridazon-desphenyl
with a LOD of 50 ng/L cannot be directly compared to that of
the other substances with LODs around 1 ng/L.
Accordingly, compounds found with high frequency are
not those found in the highest concentrations. The best
example for this category is PFOA with a high frequency of
detection of 66%, but amaximum concentration of only 39 ng/
L. Another example is DEET, which was found in 84% of the
samples (with a reporting limit of 0.4 ng/L); the concentration
levels of DEET however were inmost cases relatively low, only
15 times higher than 10 ng/L.
3.4. Chemicals exceeding 0.1 mg per liter
The compounds which were detected in the ground waters
most frequently at “elevated” concentration levels, i.e. above
the European ground water quality standard (for pesticides) of
0.1 mg/L (EC, 2006), and above 10 ng/L are depicted in Fig. 4.
Chloridazon-desphenyl was the chemical compound which
exceeded this threshold value of 0.1 mg/L most frequently (26
times), followed by NPE1C (20 times), the transformation
product of NPEO surfactants, Bisphenol A (12 times), 1H-Ben-
zotriazole (8 times), DMS (8 times), Desethylatrazine (6 times),
Nonylphenol (6 times),Chloridazon-methyldesphenyl (6 times),
Methylbenzotriazole (5 times), and so on.
In addition, chemicals which were detected often above
the level of 10 ng/L were Caffeine (48 times), Carbamazepine
(31 times), Atrazine (28 times), Simazine (26 times), Dese-
thylterbutylazine (21 times), Bentazone (20 times), Non-
ylphenol (18 times), PFOS (17 times), and DEET (15 times) (see
Fig. 4B).
3.5. Compounds detected with low frequency
Of the 59 organic chemical compounds analysed, nearly all
were detected at least once. The substances which were not
detected at all in the ground water samples were Naproxen,
Propanil, Fenarimol, Gemfibrozil, PFHxA, PFUnA, Metoxuron,
Carbaryl, and Molinate; Benzafibrate and Estrone were only
TBA [ Terbutylazine, MBTA [ Methylbenzotriazole,
DEA [ Desethylatrazine, Carbamaz. [ Carbamazepine,
DET [ Desethylterbutylazine, DNP [ 2,4-Dinitrophenol,
MBT [ Methabenzthiazuron, Chlortol. [ Chlortoluron,
TertOP [ Tert.-Octylphenol,
Sulfamet. [ Sulfamethoxazole, D24D [ 2,4-D,
T245T [ 2,4,5-T; the box is determined by the 25th and
75th percentiles. The whiskers are determined by the 5th
and 95th percentiles.
Fig. 4 e Number of detections >0.1 mg/L and >10 ng/L.
wat e r r e s e a r c h 4 4 ( 2 0 1 0 ) 4 1 1 5e4 1 2 64122
detected once. Other compounds with a relatively low
frequency of detection were Triclosan (1.8%), Linuron (2.4%),
2,4,5-T (3.7%), 2,4-D (3.7%), Alachlor (4.9%), Diclofenac (4.9%),
Dichlorprop (4.9%), Methabenzthiazuron (5.5%), Chloridazon-
methyldesphenyl (6.1%), Ibuprofen (6.7%), Chlortoluron (7.9%),
MCPA (7.9%), and Diazinon (9.1%).
3.6. Pharmaceuticals
The most relevant pharmaceutical compound for ground
water infiltration found in this study was Carbamazepine; it
was detected in 42% of the samples, with a maximum
concentration of 390 ng/L (Table 1). Carbamazepine was
detected several times in other ground water studies (Clara
et al., 2004; Drewes et al., 2002; Heberer et al., 2004;
Osenbruck et al., 2007; Rabiet et al., 2006; Sacher et al., 2001).
Its persistent character is well established, and it also has
been proposed as a possible anthropogenic marker in the
aquatic environment (Clara et al., 2004; Fenz et al., 2005). The
secondmost important pharmaceutical compound for ground
water infiltration was Sulfamethoxazole (Barber et al., 2009),
with a detection frequency of 24%, but a relatively low
maximum concentration of 38 ng/L.
3.7. Pesticides
It is obvious from Table 1 that pesticides are among the most
relevant and important chemicals found in European ground
water samples. DEET, an important insecticide, was the most
frequently detected compound in this study. Other relevant
Sample
AA01522
mins3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0 15.0
%
0
100
%
0
100
%
0
100
%
0
100
%0
100
%
0
100239 > 1392.29e3
6.1 9.6
227 > 2123.88e4
6.1
239 > 1393.45e3
6.1
227 > 2121.02e4
6.1
239 > 1393.15e3
6.1
227 > 2121.17e3
Sample
AA01150
Sample
AA01514
Bisphenol A
154 ng/L
Bisphenol A 13
C12
50 ng/L
Bisphenol A 13
C12
50 ng/L
Bisphenol A 13
C12
50 ng/L
Bisphenol A
Bisphenol A
1138 ng/L
Fig. 5 e MRM chromatograms of Bisphenol A in ground water.
wat e r r e s e a r c h 4 4 ( 2 0 1 0 ) 4 1 1 5e4 1 2 6 4123
pesticides (herbicides) or degradation products (metabolites)
detected were Atrazine, Desethylatrazine, Desethylterbutyla-
zine, Simazine, Terbuylazine, Bentazone, Propazine, Diuron,
Chloridazon-desphenyl (and methyldesphenyl), Mecoprop,
DMS, MCPA, and Dichlorprop (see Table 1). The pesticides
which exceeded the EU standard for ground water of 0.1 mg/L
most frequently were Chloridazon-desphenyl, DMS, Dese-
thylatrazine, Chloridazon-methyldesphenyl, Bentazone,
Desethylterbutylazine, DEET, and Dichlorprop (see Section
3.4. and Fig. 4); 29% of the samples contained at least one
pesticide exceeding the EU limit value of 0.1 mg/L, and 10% of
Fig. 6 e MRM chromatograms of
the ground water samples exceeded the sum limit value for
pesticides of 0.5 mg/L.
3.8. Nonylphenol ethoxycarboxylates (NPECs)
Degradation products of widely used nonylphenol ethoxylate
(NPEO) surfactants (mostly in industrial applications) include
nonylphenol (NP), nonylphenolmono- to triethoxylates (NP1-
3EO), and nonylphenol mono- and diethoxycarboxylates
(NPE1C and NPE2C). To the best of our knowledge, there are
only two publications on the occurrence of NPECs in ground
Triclosan in ground water.
wat e r r e s e a r c h 4 4 ( 2 0 1 0 ) 4 1 1 5e4 1 2 64124
water (Ahel et al., 1996; Swartz et al., 2006), which report the
apparent persistence of NPE1C and NPE2C in ground water.
NPEC oxidation products have also been observed in incuba-
tions of NPEOs with anaerobic marine sediments (Ferguson
and Brownawell, 2003), which may explain the larger NPE2C
concentrations measured by Swartz et al. (2006) in deeper
suboxic/anoxic wells relative to the shallowest well.
In our ground water monitoring study, NPE1C was among
the most relevant compounds detected, with a frequency of
detection of 42%, and a maximum concentration level of
11.3 mg/L. Our monitoring results on NPE1C in ground water
are therefore supporting these findings by Ahel et al. (1996)
and Swartz et al. (2006), and show that the NPEO carboxyl-
ates (NPECs) are persistent chemicals widespread in European
ground waters.
In addition, it is interesting to note that Octylphenol was
more often detected than Nonylphenol (detection frequency
of 23% versus 11%). Octylphenol levels were however in all
cases low; it was detected only 5 times at > 10 ng/L (max.
41 ng/L). The reporting limit of NP was >50 ng/L due to labo-
ratory blanks (Loos et al., 2008b).
3.9. Bisphenol A
Bisphenol A is one of the most highly produced chemicals
worldwide used in the production of polycarbonate plastics
and epoxy resins (Klecka et al., 2009; Oehlmann et al., 2008). In
this study, Bisphenol A was one of the most relevant
compounds detected in European ground waters, i.e. in terms
of frequency of detection (40%), and maximum concentration
levels (2.3 mg/L). Fig. 5 shows exemplary MRM chromatograms
of Bisphenol A (together with its internal standard Bisphenol
A 13C12) in two ground water samples (sample AA01522:
1138 ng/L; sample AA01150: 154 ng/L), and one example for
a negative detection.
Our results are in good agreement to the Austrian ground
water study from the year 2000, where the most abundant
industrial chemicals found in ground water samples were
Bisphenol A and NP (maximum concentrations 930 ng/L and
1500 ng/L, respectively) (Hohenblum et al., 2004). Note that in
ground water of the German city Halle, Bisphenol A and NP
levels were higher (e1 mg/L in several places) than the concen-
trations in river water of the River Saale (Osenbruck et al.,
2007; Reinstorf et al., 2008). A possible reason for this might
be the efficient removal of Bisphenol A (>80%) during waste-
water treatment (e.g. Clara et al., 2005). The ubiquitous pres-
ence of Bisphenol A in urban ground water results from
a combination of local river water infiltration, sewer exfiltra-
tion, and urban stormwater recharge/runoff (Osenbruck et al.
(2007). It appears that Bisphenol A is persistent under anaer-
obic conditions in ground water (Ying et al., 2003).
3.10. Triclosan
Triclosan, a widely used antimicrobial agent in personal care
products (Xie et al., 2008), was only detected in 3 ground water
samples (1.8% frequency) at low concentrations between 7
and 9 ng/L. Two of these samples are shown in the MRM
chromatograms of Fig. 6 together with the internal standard
Triclosan 13C12.
3.11. EUeUS ground water study comparison
A comparison of the results of this European ground water
monitoring survey with the American US study by Barnes
et al. (2008) and Focazio et al. (2008) shows a good agreement
for several organic compounds. For instance, in both studies
DEET was the most frequently detected compound. Also
Bisphenol A, Caffeine, 5-Methyl-1H-benzotriazole and Sulfa-
methoxazole were detected relatively frequently in both the
US and Europe. However, it must be noted that the absolute
frequency of detection for the compounds is not comparable
for both studies, because the reporting limit was higher in the
US-study. It is remarkable that Triclosanwas in the US ground
water study by Barnes et al. (2008) within the most frequent
detected compounds (but not in Europe), with a frequency of
detection of 15% at a reporting limit of 1 mg/L. Thus, much
higher Triclosan levels were found in the US, compared to
Europe. The analytical results for pesticides are aswell in good
agreement to an (older) US-wide monitoring study from 1993
to 1995 (Kolpin et al., 1998), where the most frequently
detected compounds were Atrazine, Desethylatrazine, Sima-
zine, Metolachlor, and Prometon.
4. Conclusions
In this ground water monitoring study 59 polar organic
contaminants could be analysed at 164 locations in 23 Euro-
pean countries. Themost relevant chemicals found for ground
water infiltration and contamination/pollution were Caffeine,
DEET, PFOA, Atrazine (and metabolites), Benzotriazoles, Ter-
butylazine (andmetabolites), PFOS, Simazine,Carbamazepine,
NPE1C, Bisphenol A, Nonylphenol, Bentazone, Chloridazon-
desphenyl, Chloridazon-methyldesphenyl, and N,N0-Dime-
thylsulfamid (DMS). Compared to river surface water, ground
water was in general less contaminated, with an average
frequency of detection for all compounds of 25%. Some
compounds such as Chloridazon-desphenyl, NPE1C, Bisphenol
A, Benzotriazoles, DMS, Desethylatrazine, Nonylphenol, and
Chloridazon-methyldesphenyl were detected in several
samples at high concentration levels in the mg/L range,
exceeding the European ground water quality standard for
pesticides of 0.1 mg per liter. For organic chemicals other than
pesticides however no threshold limit values exist in Europe.
TheMember States of the EU shall develop such limit values in
the coming years. The results of this monitoring survey are
a valuable help for identifying possible relevant compounds.
Some compounds such as Bisphenol A and Nonylphenol were
found in some ground waters at even higher concentration
levels than in surface water. More routine ground water
monitoring should be performed to identify possible “hot spot”
areas of pollution for protecting human and ecosystemhealth.
Acknowledgements
This pan-European sampling exercise received considerable
support from a significant number of participants and
involved institutions, whose concrete help is gratefully
wat e r r e s e a r c h 4 4 ( 2 0 1 0 ) 4 1 1 5e4 1 2 6 4125
acknowledged here: BRGM (France), Environment Agency
(United Kingdom), Environmental Protection Agency (Ireland),
Umweltbundesamt GmbH (Austria), IWW Rheinisch-West-
falisches Institut fur Wasser (Germany), DGRNE (Belgium),
KIWA Water Research (The Netherlands), IAREN- Instituto da
Agua da Regiao Norte (Portugal), University of Cyprus
(Cyprus), Bundesamt fur Umwelt e BAFU (Switzerland),
Statens forurensningstilsyn e SFT (Norway), GEUS - The
National Geological Survey of Denmark and Greenland
(Denmark), Water Research Institute (Slovak Republic), IRTA
Aquatic Ecosystems (Spain), Naturvardsverket (Sweden),
Maves Ltd (Estonia), University of Santiago de Compostela
(Spain), Finnish Environment Institute SYKE (Finland), Envi-
ronmental Agency of the Republic of Slovenia (Slovenia),
Vlaamse Milieumaatschappij (Belgium), Central Directorate
for Environment and Water e VKKI (Hungary), Czech Hydro-
meteorological Institute (Czech Republic), Ministry of Envi-
ronment of Ukraine (Ukraine), TUBITAK MRC CEI (Turkey),
Technical University of Crete (Greece), Administration de la
Gestion de l’Eau (Luxembourg), Bulgarian Academy of
Sciences (Bulgaria), Comune di Milano (Italy), Geological
Survey of Sweden (Sweden), Umhverfisstofnun e Environ-
ment Agency of Iceland (Iceland), Institute of Nuclear Chem-
istry and Technology (Poland), Amt der Steiermarkischen
Landesregierung (Austria), RIVM (The Netherlands).
In addition an important number of persons at the various
sampling stations has contributed to the success of this
campaign. Thanks to all of them.
Appendix. Supplementary data
Supplementary data associated with this article can be found,
in the online version, at doi:10.1016/j.watres.2010.05.032.
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