Environmental Pollution 145 (2007) 839e849
www.elsevier.com/locate/envpol
Toxic fluoride and arsenic contaminated groundwater in the Lahore and
Kasur districts, Punjab, Pakistan and possible contaminant sources
Abida Farooqi a,*, Harue Masuda a, Nousheen Firdous b
a
Department of Geosciences, Osaka City University, 3-3-138, Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
b
Geosciences Laboratory, Geological Survey of Pakistan, Chak Shehzad, Islamabad, Pakistan
Received 10 December 2005; received in revised form 3 May 2006; accepted 7 May 2006
Simultaneous As and F contamination of groundwater and possible pollutant sources are discussed.
Abstract
The present study is the first attempt to put forward possible sources of As, F and SO2
4 contaminated groundwater in the Kalalanwala area,
Punjab, Pakistan. Five rainwater and 24 groundwater samples from three different depths were analyzed. Shallow groundwater from 24 to 27 m
depth contained high F (2.47e21.1 mg/L), while the groundwater samples from the deeper depth were free from fluoride contamination. All
groundwater samples contained high As (32e1900 mg/L), in excess of WHO drinking water standards. The SO2
4 ranges from 110 to 1550 mg/L.
d34S data indicate three sources for SO2
4 air pollutants (5.5e5.7&), fertilizers (4.8&), and household waste (7.0&). Our important finding is
the presence of SO2
4 , As and F in rainwater, indicating the contribution of these elements from air pollution. We propose that pollutants originate, in part, from coal combusted at brick factories and were mobilized promotionally by the alkaline nature of the local groundwater.
Ó 2006 Elsevier Ltd. All rights reserved.
Keywords: Arsenic and fluoride pollution; Groundwater; Air pollutant; Coal combustion; Sulfur isotopes; Fluorosis; Pakistan
1. Introduction
Groundwater pollution in Kalalanwala, Kasur district, Pakistan (Fig. 1), was first officially noted in July 2000, when
a newspaper reported that residents of Kalalanwala village suffered from a mysterious bone deformity disease (22nd July,
2000 Dawn, Jang, The News). The serious nature of the problem attracted the attention of domestic and international media
(The Nation, July 2000). More than 400 residents were diagnosed with bone disease, which included common complaints
of joint and back pain. Bone deformation and spinal defects
were also observed. Children were especially affected; 72
patients were under 15 years of age (Table 1).
* Corresponding author. Tel.: þ81 6 6605 2591; fax: þ81 6 6605 2522.
E-mail address: [email protected] (A. Farooqi).
0269-7491/$ - see front matter Ó 2006 Elsevier Ltd. All rights reserved.
doi:10.1016/j.envpol.2006.05.007
Arsenic contamination of local groundwater had been previously identified in the area (Naseem et al., 2001) and some
people believed the arsenicosis caused the local disease, while
the symptoms of patients in the Kalalanwala area were consistent with fluorosis. Fluoride ion concentrations of approximately 1 mg/L reduce dental caries, however, F >2 mg/L
causes discoloration of teeth, and the higher concentration
causes bone fragility and deformation (Lee, 1991).
Fluoride contaminated groundwater has previously been
reported in south Asian countries. The main source of F in
these groundwaters is considered to be fluorine-bearing
minerals such as fluorspar, cryolite, fluorapatite, and hydroxyapatite found in local rock and sediment (Sarma and Rao,
1997; Datta et al., 2000). Endemic fluorosis resulting from
high F concentrations in groundwater is an acute public
health problem in India. The F affects about 25 million people in 150 districts (Rajiv Gandhi Survey Report, 1993) where
this element is believed to enter groundwater from the
A. Farooqi et al. / Environmental Pollution 145 (2007) 839e849
840
Table 1
Characteristics of children affected with bone deformity disease in Kalalanwala, Kasur (n ¼ 72; Jahangir and Nabeel, 2001)
Parameter
Characteristics
Number
of patients
Age
1e5 years
6e10 years
11e15 years
>15 years
Male
Female
381
24
31
16
01
42
30
Gender
Total number of
households in
Kalalanwala village
Total population of
Kalalanwala village
Number of cases
reported with bone
deformity disease
Typical clinical
presentation main
bones & joints involved
Dental problems
Typical radiological
findings in various bones
3042
72
Femur, tibia, fibula,
Knee joints, humurus,
radius, ulna, small
joints of hand
Dental caries, teeth molting,
brown discoloration of teeth
Coarsening trabeculae
Osteosclerosis
Growth arrestation
Calcification at the site
of tendon insertions
dissolution of fluorine-rich minerals (Wenzel and Blum,
1992). In China, more than 100 million people, over more
than 20 provinces, suffer from fluorosis of varying severity
(Wang et al., 1999).
Among the anthropogenic sources of F in the environment
are coal combustion causing air pollution, and waste production by various industries, including steel, aluminum, copper
and nickel smelting; and the production of glass, phosphate
fertilizers, brick and tile (Pickering, 1985; Skjelkvsle, 1994).
Simultaneous air and groundwater pollution by F and As,
due to coal combustion, causes serious health diseases over
large areas of southern China (Zheng et al., 1996; An et al.,
1997; Finkelman et al., 2002) and Inner Mongolia (Wang
et al., 1999; Smedley et al., 2002), although F does not coexist with As in polluted groundwater in most other areas.
Highly As contaminated (>50 mg/L) groundwater has been
reported in various parts of the world, including Argentina,
Bangladesh, Chile, China, Hungary, West Bengal (India), Mexico, Taiwan, Vietnam and many parts of the USA (Smedley
et al., 2002). Large scale As contamination occasionally appears in recent sediments, and the regions most affected by arsenicosis are the modern Ganges Delta area of West Bengal,
India, and Bangladesh (Mukherjee and Bhattacharya, 2001;
Bhattacharya et al., 2002a,b; Smedley and Kinniburgh, 2002).
Arsenic contaminated groundwater is also a serious problem in Pakistan at present. Based on the monitoring program
of groundwater quality, the Pakistan Council of Research in
Water Resources (PCRWR) and UNICEF reported that As
contaminated groundwater (10e200 mg/L) is found in many
areas of the country (Arsenic). According to the report, F
is contained in most groundwater, however, concentrations
are commonly <1 mg/L, with the highest concentration at
2.8 mg/L (Arsenic). Also, no specific correlation between As
and F content was observed in the monitored groundwater.
The Public Health Engineering Department of Pakistan, in collaboration with UNICEF, recently revealed that As-enriched
groundwater occurs in the Indus alluvial basin, and that the
highest As concentration was 906 mg/L in the Muzaffargarh
district, southwest Punjab (Nickson et al., 2005).
A reconnaissance survey of groundwater at Kalalanwala
and Kot Asadullah was undertaken during November 2002
to investigate the level of F and As contamination and to
identify the formation mechanism of the contaminated
groundwater. In the current paper, we first characterize the
geochemical data of the highly F and As contaminated
groundwater in those areas, and then discuss possible sources
of pollutants.
2. Geography and geology of the study area
The Punjab province, southeast Pakistan, is located between 24e37 N and 62e75 E, within an alluvial plain of
the south-flowing Indus River and its five major tributaries.
Lahore, the capital of the Punjab province and the second largest city in Pakistan, is situated on the east bank of the Ravi
River (Fig. 1).
Quaternary sediments, mainly of alluvial and deltaic origins, occur over large parts of the Indus Plain of Pakistan, predominantly in Punjab province, where the thickness of those
sediments occasionally reaches several hundred meters
(WAPDA-EUAD, 1989). The sediments comprised mostly
coarse sand, containing a high percentage of fine to very
fine sand and silt. Clay particles consist of non-swelling minerals (Greenman et al., 1967).
The sedimentary formations along the Indus River system are
similar to those that include the As contaminated aquifers in the
sedimentary basins associated with the GangaeBrahmaputra
River system in Bangladesh and West Bengal, composed of
Quaternary alluvial-deltaic sediments derived from Himalayan
source rocks. However, the sedimentary basins along the Indus
River system, located at the western edge of the Asian monsoon
area, are in a more arid climate than other sediments. The older
Quaternary (i.e., Pleistocene) deposits are more widely distributed in the western sedimentary basin, probably promoting
more aerobic aquifer conditions in the study area than in
the other locations (Cook, 1987; Mahmood et al., 1998;
Tasneem, 1999).
The Punjab province has a semiarid and subtropical continental climate characterized by sultry summers and cold winters. The mean annual maximum temperature recorded from
May to June is 41 C. The rainy monsoon season occurs for
two and a half months beginning in late June. January is the
coldest month, with a mean annual minimum temperature of
4 C. The average annual precipitation is about 510 mm,
with approximately two-thirds falling during the monsoon season. The total annual excess of evaporation over precipitation is
A. Farooqi et al. / Environmental Pollution 145 (2007) 839e849
841
Fig. 1. Index map of Pakistan showing the location of the study area.
about 700 mm, and is at a maximum (130 mm) during May and
June. Total monthly evaporation is comparable to total monthly
precipitation during July and August (Ali et al., 1968).
Kalalanwala and Kot Asadullah are ancient villages located
on fertile agricultural land in the flood plain of the Ravi River,
one of the major tributaries of the Indus River. Fertilizers such
as Diammonium phosphate (DAP) and urea are extensively
used in this agricultural region. The area, which has a population of 3040, is adjacent to a modern industrial area, 45 km
south of Lahore. Many brick factories were observed in or
near the study area. For daily water use, including drinking
water, most of the residents use groundwater, extracted from
tube wells and excavated wells within individual dwellings.
3. Sampling and analytical methods
Twenty-four groundwater samples were collected during November 2002, including 17 samples from shallow hand-pumped
wells at 24e27 m depth; three samples from electricallypumped tube wells used to supply drinking water at 60e90 m
depth; and, four samples from electrically-pumped irrigation
wells at 165e183 m depth. Five rainwater samples were also
collected from the study area and stored in polyethylene bottles.
Rainwater samples 1, 2, and 3 were collected during the monsoon season in September 2004, while samples 4 and 5 were collected in February 2005.
In the field, we measured water temperature, electrical
conductivity (EC), pH and alkalinity. Water samples were collected in two polyethylene bottles; one of these was acidified
to be 0.06 N HCl solution for the quantitative analysis of cations (Naþ, Kþ, Ca2þ, and Mg2þ), total As, and sulfur isotope
ratios. The other aliquot was kept non-acidified for anion (Br,
2
2þ
conCl, F, PO3
4 , and SO4 ) analysis. Calcium and Mg
centrations were analyzed by volumetric titration using ethylenediaminetetraacetic acid (EDTA 0.05 N) with an analytical
error <2%. Naþ and Kþ concentrations were determined by
atomic absorption spectrometry with an error <3% (SAS
7500, Seiko and Hitachi Zeeman 8100, respectively). Br,
2
Cl, F, PO3
concentrations were determined
4 , and SO4
by ion chromatograph (DX-120, Dionex) with an error
<2%, estimated from the duplicated analysis of the standard
stock solutions. Total As was analyzed by hydride generation
atomic absorption spectroscopy (SAS 7500, Seiko) using
a standard calibration line made with commercially distributed
standard stock solution. The reproducibility of the analytical
data is within 5%, and the accuracy is estimated to be
<10%, based on the analytical results of standard stock solutions independently prepared using commercially distributed
standard solution. The detection limits (ca 0.5 mg/L) were
determined from the lowest concentration of the standard
solution giving the optical peak.
For sulfur isotope analysis, sulfate was precipitated as
BaSO4 by adding 10% BaCl2 solution to water samples.
BaSO4 was collected upon 0.45 mm filter paper, and then
ignited to obtain pure BaSO4. Sulfur isotope analysis was performed on SO2 gas prepared by thermal decomposition of
BaSO4 mixed with V2O5 and SiO2, following the method of
Yanagisawa and Sakai (1983). Isotope analyses were undertaken using a mass spectrometer VG SIRA 10 at the Institute
for the Study of the Earth’s Interior, Okayama University,
Japan. The obtained isotope ratios are expressed in the familiar
delta notation d34S as given in the formula below, referring to
the Canyon Diablo Troilite (CDT) scale. The analytical precision for d34S was <0.2&.
A. Farooqi et al. / Environmental Pollution 145 (2007) 839e849
842
Ssample =32 Ssample
1
1000
d S ¼ 34
ð Sstandard =32 Sstandard Þ
34
34
ð1Þ
To estimate the equilibrium condition of the minerals
possibly controlling the soluble chemical species, saturation
indices were calculated using speciation modeling PHREEQC
(USGS, 2005). The saturation indices (SI) are expressed as
follows for fluorite (Eq. (2)), calcite (Eq. (3)), dolomite (Eq.
(4)), and gypsum (Eq. (5)):
!
2
aCa2þ ðaF Þ
SIf ¼ log
ð2Þ
Ksp ðfluoriteÞ
aCa2þ aCO2
3
SIc ¼ log
Ksp ðcalciteÞ
ð3Þ
aMg2þ aCO2
3
SId ¼ log
Ksp ðdolomiteÞ
ð4Þ
aCa2þ aSO2
4
SIg ¼ log
Ksp ðgypsumÞ
ð5Þ
The solubility product constants (Ksp) used for the calculation at 25 C are as follows: 3.45 1011 for CaF2 (fluorite);
3.36 109 for CaCO3 (calcite); 6.82 106 for dolomite
(MgCO3); and, 3.14 105 for gypsum (CaSO4$2H2O).
up to 224 mg/L. The groundwater temperature is notably
higher (27.3e28.8 C) than those of the other two groups
of groundwater.
Deep groundwater (n ¼ 4) has a pH range of 7.4e7.9. The
alkalinity is up to 433 mg/L, SO2
4 up to 718 mg/L, Na ranges
from 234 to 300 mg/L, Ca2þ of 65.6e89.6 mg/L, and Cl up
to 110 mg/L. Middle and deep groundwater have NO
3 -N of
<10 mg/L. The major ion composition of this water group is
similar to that of the middle groundwater, while the water temperature is low (25.2e26.9 C). Since water temperature is
one of the conservative properties in the water cycle, the difference in temperature ranges between the middle and deep
groundwater is suggestive of the presence of two separate
confined aquifers.
Rainwater has a pH range of 6.9e7.1, alkalinity up to
12 mg/L, SO2
ranging from 5 to 14 mg/L, Naþ 2.62e
4
6.7 mg/L and Ca2þ 6.4e10 mg/L. Sulfate concentrations of
the studied groundwater show a positive correlation
(r2 ¼ 0.95, n ¼ 24) with Cl (Fig. 3), indicating that most
groundwater is a mixture of at least two independently
recharged waters. Rainwater is considered to be one of the
recharging sources in the area, and Ravi River water is the
one of the other possible sources, although it cannot be specified at present. Another source that contributes high Cl and
SO2
4 concentrations may be anthropogenic, and will be discussed in detail later in the text.
4. Results
4.2. Fluoride and arsenic concentrations
The results of the chemical analyses are summarized in
Table 2. For convenience in description, groundwater samples are grouped into three categories according to well
depth: groundwaters sampled from 24 to 27 m deep wells
(shallow groundwater); 60e90 m (middle groundwater);
and, 165e183 m (deep groundwater). The charge balance
of total cations and anions (meq/L) is assured to be <5%,
as given in Table 2.
4.1. Major ion composition
The dissolved component characteristics of three groups of
groundwater and rainwater are summarized in Table 3. All
shallow groundwater (n ¼ 17) is alkaline, pH 7.3e8.7. Alkalinity, expressed as HCO
3 , ranges between 579 and
1900 mg/L. Sulfate is the one of the dominant anions, with
a concentration range of 284e1550 mg/L (Fig. 2), Cl ranges
from 20.4 to 299 mg/L, while Naþ, the most dominant cation,
is 301e878 mg/L. Calcium concentrations are notably low,
ranging from 8.4 to 44.8 mg/L. Six shallow groundwater samples (KLW-1, 3, 7, 11, 16 and 17) contain NO
3 -N above the
WHO standard for drinking water (10 mg/L). The highest concentration of NO
3 -N is 64 mg/L in KLW-16, probably due to
the use of fertilizers in the area.
Middle groundwater (n ¼ 3) pH range is 7.6e7.8. The
alkalinity of the middle groundwater ranges within 237e
363 mg/L, SO2
is up to 906 mg/L, and Naþ up to
4
2þ
380 mg/L, Ca concentrations of 59.2e129 mg/L, and Cl
All shallow groundwater samples except KLW-4 contain
F > 1.5 mg/L, which is the WHO drinking water standard.
The highest concentration is 21.1 mg/L. In contrast, F concentrations in groundwater from the middle and deep wells
are below WHO standards, except for TWI-7, which contains
2.85 mg/L of F. Samples with high F concentrations
invariably have low concentrations of Ca2þ (Fig. 4) and
high concentrations of Naþ. Rainwater samples (n ¼ 5) contain F in the range of 0.16e0.28 mg/L, indicating that F in
the groundwater originates in part from dissolved air
pollutants.
Arsenic concentrations range from 32 to 1900 mg/L in the
analyzed groundwater samples. All the samples, irrespective
of the depth, contain As in excess of the WHO guideline
(10 mg/L), however, As concentrations tend to be higher in
the shallow groundwater samples, which give high pH ranging
7.3e8.7. Sample KLW-17 has a pH of 8.5 and the highest concentration of As at 1900 mg/L. An important finding of this
study is that four of five rainwater samples contain As in
excess of 10 mg/L, with a maximum value of 90 mg/L; this
indicates a clear contribution of atmospheric pollutants to
the contamination of groundwater.
Fig. 5a and b shows distribution maps of F and As in the
study area. The concentrations of these elements are poorly
correlated with each other; however, both elements are enriched in shallow groundwater, suggesting the contribution
of a common source or pathway for both elements.
Table 2
Major element chemistry, arsenic concentrations and sulfur isotope ratios of rain and groundwaters from Kalalanwala, Pakistan
Sample
I.D.
24e27
24e27
24e27
24e27
24e27
24e27
24e27
24e27
24e27
24e27
24e27
24e27
24e27
24e27
24e27
24e27
24e27
60e90
60e90
60e90
165e183
165e183
165e183
165e183
pH
T
( C)
EC
(mS/cm)
Alkalinity
(HCO
3)
mg/L
Ca2þ
(mg/L)
Mg2þ
(mg/L)
Naþ
(mg/L)
Kþ
(mg/L)
NHþ
4
(mg/L)
Tct
(meq/L)
F
(mg/L)
Cl
(mg/L)
Br
(mg/L)
NO
3 -N
(mg/L)
PO3
4
(mg/L)
SO2
4
(mg/L)
Tan
(meq/L)
As
(mg/l)
d34S
(&)
7.1
6.9
7.0
7.1
7.0
7.3
8.0
8.0
7.5
8.0
8.0
8.1
8.0
7.8
8.0
8.1
8.1
8.7
8.0
8.0
8.0
8.5
7.6
7.8
7.8
7.5
7.4
7.4
7.9
24.1
25.0
24.8
24.7
23.0
25.5
25.9
25.6
25.4
25.3
25.6
24.1
25.7
25.2
25.2
24.7
24.7
23.5
25.7
25.1
24.6
23.5
27.9
28.8
27.3
25.2
25.9
26.9
25.5
0.05
0.09
0.07
0.07
0.06
2.92
2.42
2.62
2.36
1.18
1.28
1.92
2.78
2.41
2.65
2.47
2.78
1.45
2.34
3.10
3.06
2.19
1.86
0.37
0.36
1.42
1.61
1.37
0.47
12.0
12.0
11.0
10.0
12.0
788
859
686
1895
610
718
866
1031
816
735
854
1003
835
829
860
610
579
363
237
274
431
410
433
365
10.0
6.4
9.0
7.5
8.0
44.8
28.0
32.0
35.0
22.0
8.8
14.4
24.4
21.6
27.2
8.4
16.0
10.4
15.6
22.8
19.6
13.2
129
59.2
71.2
89.6
89.6
65.6
52.4
1.02
2.03
1.02
1.04
2.00
31.4
26.5
15.3
21.0
13.1
16.3
10.7
11.4
12.4
12.4
5.6
22.1
8.0
9.0
18.7
16.1
3.6
73.0
28.5
32.6
63.7
78.0
31.0
26.3
2.62
6.70
4.20
3.50
6.50
696
644
679
629
301
352
526
771
656
700
701
661
411
646
878
826
638
380
68.0
102
283
300
276
234
0.64
1.75
0.52
0.43
1.20
6.30
5.50
5.50
5.90
4.30
3.50
3.90
4.70
4.70
5.50
4.70
5.90
3.50
5.10
5.80
5.50
4.70
5.10
2.74
3.13
4.70
5.50
4.70
3.50
e
e
e
e
e
0.03
0.02
0.03
0.04
0.18
0.13
0.21
0.03
0.04
0.04
0.07
0.04
0.07
0.74
0.03
0.21
0.07
0.07
0.15
0.24
0.34
0.07
0.18
0.08
0.44
0.62
0.47
0.43
0.57
32.8
29.9
31.1
29.2
14.3
16.3
23.8
34.7
29.7
31.7
31.0
30.2
18.5
29.0
39.6
37.2
28.3
22.8
5.71
7.63
17.3
18.6
15.0
12.6
0.23
0.28
0.18
0.23
0.16
8.55
7.03
10.0
0.95
2.47
5.89
21.1
21.1
19.8
16.4
10.8
14.3
3.80
19.8
7.80
15.6
3.42
0.57
0.57
0.38
1.52
1.15
0.38
2.85
4.0
4.2
4.1
5.3
5.1
264
175
232
141
38.2
20.4
84.4
171
173
194
158
120
56.3
134
253
299
192
224
13.1
29.3
110
130
100
74.2
bdl
bdl
bdl
bdl
bdl
0.56
0.48
0.56
0.32
bdl
bdl
0.16
0.48
0.48
0.48
0.01
0.40
0.08
0.40
0.64
1.12
0.48
0.40
bdl
0.08
0.24
0.32
0.24
0.16
1.5
3.8
1.5
1.4
1.3
24.3
bdl
20.2
bdl
2.1
bdl
10.6
0.3
bdl
2.2
11.0
5.6
0.1
5.6
bdl
64.0
10.0
bdl
bdl
1.0
0.1
bdl
bdl
bdl
bdl
0.34
0.62
0.53
0.49
bdl
bdl
bdl
bdl
bdl
bdl
0.09
0.38
0.19
0.28
0.57
0.19
0.28
0.47
0.00
0.57
2.18
bdl
bdl
bdl
bdl
bdl
bdl
bdl
5.00
14.0
9.00
7.00
9.00
1213
939
1111
926
284
299
573
1082
960
1170
1009
850
321
867
1551
1497
1112
906
112
193
597
718
562
396
0.47
0.72
0.50
0.49
0.53
33.8
29.1
30.2
28.3
14.2
15.7
23.8
34.1
29.3
30.6
29.7
29.5
18.8
27.5
37.8
35.8
26.8
21.7
5.44
7.37
16.4
17.9
15.8
12.3
30.0
90.0
19.0
<10.0
15.0
68.0
227
110
111
62.0
153
60.0
130
132
135
530
192
66.2
84.1
68.3
144
1900
53.0
47.0
32.2
68.0
72.0
61.0
50.0
e
e
e
e
e
4.80
6.50
5.50
6.30
5.60
6.20
5.70
5.50
5.60
5.70
5.50
5.60
7.00
5.50
4.70
4.80
5.50
5.60
5.60
5.70
5.50
5.60
5.70
5.60
A. Farooqi et al. / Environmental Pollution 145 (2007) 839e849
RAIN-1
RAIN-2
RAIN-3
RAIN-4
RAIN-5
WKA-1
WKA-2
WKA-3
WKA-4
WKA-5
WKA-6
WKA-7
WKA-8
WKA-9
WKA-10
WKA-11
WKA-12
WKA-13
WKA-14
WKA-15
WKA-16
WKA-17
DKW-1
DW-2
DWHF-3
TWI-1
TWI-3
TWI-5
TWI-7
Depth
(m)
The abbreviations gives the different types of water samples as follows: RAIN e rainwater; WKA e shallow groundwater from Kalalanwala; DKW, DW, and DWHF e groundwater from the middle depth; TWI e
deepest groundwaters among the studied samples.
‘‘ e’’ means not analyzed.
bdl stands for below detection limit.
843
A. Farooqi et al. / Environmental Pollution 145 (2007) 839e849
844
Table 3
Ranges of analytical data of the different types of water samples from Kalalanwala, Pakistan
Parameter
Water type
Shallow groundwater (24e27 m)
# of samples n ¼ 17
EC
pH
Alkalinity
(HCO
3)
SO2
4
Cl
PO3
4
Br
NO
3 -N
F
Ca2þ
Mg2þ
Naþ
Kþ
As
Middle groundwater (60e90 m)
n¼3
Deep groundwater (165e183 m)
n¼4
Rainwater
n¼5
Min
Max
Mean
Min
Max
Mean
Min
Max
Mean
Min Max
mg/L
1.18
7.3
579
3.1
8.7
1895
2.34
8.00
857
0.36
7.6
237
1.86
7.8
363
0.86
7.7
291
0.47
7.4
365
1.61
7.9
433
1.21
7.55
410
0.1
6.9
5.0
0.09
7.1
14.5
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
284
20.4
Bdl
bdl
bdl
0.95
8.40
3.64
301
3.50
60.0
1551
299
2.18
1.12
64
21.1
44.8
31.4
878
6.3
1900
929
159
0.31
0.39
9.00
11.0
21.4
15.0
630
5.00
235
112
13.1
bdl
bdl
bdl
0.38
59.2
28.5
68.0
2.74
32.2
906
224
bdl
0.4
1.0
0.57
129
73
380
5.1
53
404
89
bdl
0.16
0.41
0.58
86
44.7
183
3.6
45
396
74.2
bdl
0.16
bdl
0.38
52.4
26.3
234
3.5
50
718
130
bdl
0.32
0.1
2.85
89.6
78
300
5.5
72
568
104
bdl
0.24
0.03
1.47
74.3
50
273
4.6
60
5.0
4.0
bdl
bdl
1.3
0.2
6.4
1.0
6.4
0.4
0.0
14
8.8
5.3
4.5
0.62 0.4
bdl
bdl
3.8
1.9
0.28 0.22
10
8.2
2
1.4
10
8.0
1.75 0.9
90
30.0
(mS/cm)
Mean
0.06
7.0
9.0
bdl stands for below detection limit.
3
Detection limits for Br, NO
3 -N and PO4 are 0.02, 0.05 and 0.025, respectively.
4.3. Sulfur isotopes
Stable isotope ratios of sulfateesulfur vary in a narrow
range from 4.7 to 7.0&. The relationship between SO2
4 concentration and d34S indicates at least three different sources of
sulfur in the analyzed groundwater (Fig. 6). The d34S values of
the three end members are 5.5e5.7& (A), 4.7e4.8& (B), and
about 7.0& (C). End member A contains the least
2
SO2
4 <20 mg/L, while B contains >1550 mg/L SO4 , and
C 320 mg/L. Most of the analyzed waters plot within a triangle
connecting the three end members. All samples from the middle and deep aquifers have d34S values of 5.5e5.7& (CDT).
These samples contain less soluble salts, including F and
As, than the shallow groundwater, and are therefore the least
Fig. 2. Relationship between SO2
and HCO
4
3 concentrations in analyzed
water samples. Triangles represent shallow groundwater (24e27 m), circles
represent middle well water (60e90 m), and crosses indicate deep well water
(165e183 m). SO2
4 is dominant anion as indicated by the dashed area.
polluted waters. Most of the middle and deep waters plot in
an area close to A (Fig. 6), suggesting that these waters are
not seriously polluted following recharge.
5. Discussion
Our study reveals high concentrations of F and As in
Kalalanwala groundwater. Elevated concentration of F, up
to 21.1 mg/L in groundwater from 20 to 27 m depth, is clearly
the cause of tooth discoloration and bone deformation among
residents.
The F rich waters are characterized by high concentrations of Naþ and low concentrations of Ca2þ and Mg2þ.
Low Ca2þ results from the intense cation exchange reaction
Fig. 3. Relationship between Cl and SO2
4 concentrations in analyzed water
samples. Triangles represent shallow groundwater (24e27 m), circles indicate
middle well water (60e90 m), crosses indicate deep well water (165e183 m),
and squares indicate rainwater.
A. Farooqi et al. / Environmental Pollution 145 (2007) 839e849
845
Fig. 4. Relationship between F and Ca2þ concentrations in analyzed water
samples. Symbols are as described in Fig. 3.
between Ca2þ and Naþ (Sarma and Rao, 1997). High HCO
3
concentrations and alkaline pH promote the precipitation of
Ca2þ as calcite (Sarma and Rao, 1997) and Mg2þ as dolomite,
and all of the studied groundwaters are saturated with those
minerals (Fig. 7a and b).
Fluoride ions are adsorbed by clays in acidic solution; however, they are desorbed in alkaline solution. Thus, an alkaline
pH is favorable for F dissolution (Sexena and Ahmed,
2003). In the present case, all shallow groundwater samples
were weakly alkaline, with pH 7.3e8.7. The saturation index
of fluorite (SIf) increases with increasing F concentration,
and reaches the saturation state when the F concentration is
>8 ppm (Fig. 7c). Nine of 24 shallow groundwater samples
are saturated with fluorite (Fig. 7a). In contrast, the Ca2þ concentrations do not show a clear relationship with SIf (Fig. 7b
and d). These facts indicate that low concentrations of Ca2þ
and Mgþ promote high concentrations of F in the studied
groundwater, and that the upper limit of F concentrations is
controlled by fluorite solubility. The saturation index of gypsum
(SIg) shows a good correlation with Ca2þ and SO2
4 (Fig. 7e and
f), although all of the groundwater is undersaturated with respect to this mineral. Instead of a higher concentration of
SO2
4 in the shallow groundwater than in the middle and deep
groundwater, SIg is much lower in the former groundwater
than in the latter ones because Ca2þ depletion from the groundwater is more intense in the shallow groundwater.
One of the mechanisms of high F concentrations in
groundwater in arid and semiarid regions is the condensation
of soluble components due to evaporation and evapotranspiration (Jacks et al., 2005). Although this mechanism could not
be evaluated at present due to the small study area, we suppose
that the evaporationecondensation mechanism would not be
important in the studied groundwater, since there is no good
positive correlation between F and Cl (r2 ¼ 0.21, n ¼ 24),
which is the most conservative element during evaporation
and condensation. Chloride also shows a positive correlation
with Naþ (r2 ¼ 0.79, n ¼ 24), while Ca2þ, Mg2þ and HCO
3
Fig. 5. Distribution maps of fluoride (a) and arsenic (b) concentrations in the
study area.
are not well correlated with Cl (r2 ¼ 0.14, 0.006, 0.21,
respectively, n ¼ 24). In the future, an extended study area
and additional sample analysis are needed to provide more
details of the effects of evaporationecondensation.
Sulfate concentrations are high in our groundwater samples, especially in the shallow groundwater. As noted above,
SO2
is derived at least from three sources (points A, B,
4
and C in Fig. 6). Water A is the least polluted water, with
846
A. Farooqi et al. / Environmental Pollution 145 (2007) 839e849
Fig. 6. Relationship between SO2
4 and sulfur isotope ratios. Line triangles
represent shallow groundwater with constant d34S and increasing SO2
4 solid
rectangles represents middle and line rectangles represents deep groundwater,
diamonds represent shallow samples with low d34S and high SO2
4 , solid triangles indicate shallow samples with high d34S low SO2
4 . The dashed area
of triangle indicates three end members, while the solid line from A to B indicates the increase of SO2
4 with input of some anthropogenic source with
constant d34S values.
low F (0.4e0.6 mg/L), As (32e47 mg/L), Cl (13e29 mg/
L), SO2
(112e193 mg/L), and d34S values of 5.6&. The
4
2
SO4 in these waters possibly originates from rainwater. The
d34S values in the range þ4 to þ5& are considered typical
of atmospheric SO2
(Kramer and Snyder, 1977; Newman
4
and Forrest, 1991). In a recent study held in the Sichuan basin,
China, Li et al. (2006) demonstrated that d34S 4e6& of SO2
4
in the groundwater originated from coal combustion air pollutants. The authors also found an increasing isotopic ratio with
increased input of local household wastewater and a decreasing
isotopic ratio with increased fertilizer input.
Water B contains high amounts of Cl and SO2
up to
4
1500 mg/L, low d34S values (4.8&), close to those found in
fertilizer (5.4&, Moncaster et al., 2000). Fluoride and As concentrations vary widely in these groundwaters, and are not always associated with high SO2
concentrations. The d34S
4
value of water C is 7.0&, close to that of household detergents
(þ8.5 to þ13.6&, Laura et al., 2004). Water C contains comparatively low F (0.95e7.0 mg/L) and As (66e230 mg/L)
among the studied waters.
Most of the groundwater samples plot a line connecting A
and D. The d34S of these groundwaters does not change with increasing SO2
concentration. This group of groundwaters
4
could have been formed by two possible mechanisms: (1) evaporation of water A, or (2) mixing of waters A and D. We con
sider that mechanism (1) is improbable, since SO2
4 /Cl
ratios of groundwater (factor > 4) are higher than those of
the rain (factor < 2.5), indicating the additional input of
sulfate into the groundwater rather than only the evaporationeconcentration. Thus, we prefer mechanism (2). Two
origins are possible for water D: a mixture of B and C, or that
the fourth end member water coincidentally has the same
d34S as rainwater. Neither of these possibilities can be discounted at present.
Highly As(V) contaminated groundwaters in oxidizing environments throughout the world are characterized by high con2
centrations of HCO
(>250 mg/L),
3 (>500 mg/L) and SO4
and pH > 7.5 (Smedley et al., 2002). Arsenic speciation was
not completed in the present study, although these general characteristics are consistent with the analyzed groundwater. In ad2
dition to the high HCO
3 and SO4 concentrations, most of the
shallow groundwater, especially highly As contaminated
þ
groundwater, contain dominant NO
3 comparative to NH4 , indicating the oxidizing condition for permitting As(V) as a dominant chemical form of As.
In general, inorganic As is known to be more hazardous
than organic As compounds, and inorganic As(III) is 60 times
more hazardous than As(V) (Ferguson and Gavis, 1971). We
did not observe obvious cases of arsenicosis in the studied
area because low toxicity arsenate would be dominant in the
local groundwater. However, the chronic intake of high
As(V) groundwater would potentially cause health hazards
in future over a long range period, since this element is
reduced into arsenite, which is accumulated in the human
body, and arsenite is more difficult to remove from drinking
water supplies than arsenate (Gupta and Chen, 1978; Schneiter
and Middlebrooks, 1983).
Coincidental occurrence of high F, As and SO2
in
4
rainwater and studied groundwater implies that air pollutants
originating from coal combustion at brick factories scattered
in the study area are a source of these elements. Burning mineralized coal is known to emit toxic elements such as As and
F (Finkelman et al., 2002). In the US and South Africa, As
causes lung cancer, cardiopulmonary and respiratory illnesses,
such as asthma, due to the direct inhalation of gases produced
by the combustion of coal (Cgag). In the southwest Guizhou
Province, 3000 people have been affected by As and F pollution due to domestic combustion of coal, which contains highly
concentrated As (Ding et al., 2001). People are ingesting those
elements directly from the air inside local residences, and indirectly from the contaminated groundwater (Zheng et al., 1996).
The AS and F contamination process of those elements in our
studied area seems to be analogous to the case in China. In the
study area, coal is combusted in the open air, thus the direct effects from the air on the people are not as serious as in the case
in China. However, the semiarid climate promotes intense soil
pollution due to the condensation of those elements, causing
more serious groundwater contamination.
At Muzaffargarh district, Punjab, Pakistan, direct input of
As from industrial or some agricultural chemicals, or indirectly released As, once fixed in the sediments, associated
with the reduction of hydrous ferric oxide (HFO) are the
pollutant sources of groundwater (Nickson et al., 2005). There
was no serious contamination of F in the study area, in
contrast to other areas in Pakistan (PCRWR 2003; Nickson
et al., 2005). The sources of F and As would differ in the
other parts of the country, and geochemical conditions of the
studied groundwater would be unique, promoting the release
of air pollutants from the sediments into the groundwater.
A. Farooqi et al. / Environmental Pollution 145 (2007) 839e849
847
Fig. 7. Relationships between various chemical components of analyzed water samples. Fluorite saturation index (SIf) and calcite saturation index (a), fluorite
saturation index and dolomite saturation index (b), fluorite saturation index (SIf) and F (c), fluorite saturation index and Ca2þ (d), gypsum saturation index
and Ca2þ (e), and gypsum saturation index and SO2
4 (f). Symbols are as described in Fig. 2.
6. Conclusions
The current study demonstrates that groundwater from the
Kalalanwala area, Punjab province, Pakistan, is heavily contaminated with As, F and SO2
4 . The geochemical characteristics and origin of the contaminated groundwater can be
summarized as follows:
1. Groundwater from shallow wells (24e27 m depth) has F
content up to 21.1 mg/L, with low Ca2þ and Mg2þ concentrations. Fourteen among 17 shallow groundwater samples
show alkaline pH > 8. Groundwater from two deeper depths
does not contain serious amount of F, and pH is <7.9.
2. Most of the studied groundwater is NaeHCO
3 or Nae
2
HCO
eSO
dominant.
High
concentrations
of Naþ
3
4
must have resulted from the intense cation exchange reaction with Ca2þ and carbonate precipitation under alkaline
conditions. Fluoride concentration is controlled by fluorite
solubility under such conditions.
3. Sulfate derived from air pollutants widely contaminates
the groundwater, and fertilizer and household wastewater
also contribute high concentrations of SO2
4 .
848
A. Farooqi et al. / Environmental Pollution 145 (2007) 839e849
4. Although groundwater is strongly enriched in As irrespective of depth, contamination is most intense at shallow
depths of 24e27 m. Arsenic is in the form of less toxic
arsenate. The maximum concentration (up to 1900 mg/L)
recorded in this study is the highest As concentration
known in Punjab.
5. Arsenic, F, and SO2
4 were detected in local rainwater.
Our observations indicate that As, F, and SO2
4 contaminants are in part derived from air pollutants plausibly resulting from coal combustion by the brick factories in the
area. Low alkaline earth concentrations in the groundwater
and alkaline pH act to promote groundwater contamination by these elements.
Acknowledgments
We are grateful to Mr. M. Sakhawat, Director of Geoscience Laboratory, Geological Survey of Pakistan, Islamabad,
for providing all necessary facilities for field and laboratory
work. We appreciate Prof. M. Kusakabe, Institute for the Study
of the Earth’s Interior, Okayama University, for his valuable
suggestions and guidance of the sulfur isotope analysis. Special thanks are given to Drs. T. Shirahase and S. Yamasaki
for their sincere arguments in the field. Technical support from
Ms. K. Okazaki, Osaka City University, is appreciated. The
authors are indebted to Mr. M. Naseem and Ms. N. Haider,
Geoscience Laboratory, Geological Survey of Pakistan, for
laboratory assistance. This work was financially supported
by JICA (Aftercare project for Geoscience Laboratory) and
JSPS (Scientific aid: No. 12440145).
References
An, D., He, Y.G., Hu, O.X., 1997. Poisoning by coal smoke containing arsenic
and fluoride. Fluoride 30, 29e32.
Ali, A.M., Farooq, M., Hameed, A., Afzal, M., Brinkman, B., 1968. Reconnaissance soil survey of Lahore district. Soil Survey Project of Pakistan.
Soil Survey of Pakistan, 207 pp.
Bhattacharya, P., Frisbie, S.H., Smith, E., Naidu, R., Jacks, G., Sarkar, B.,
2002a. Arsenic in the environment: a global perspective. Handbook of
Heavy Metals in the Environment. Marcell Dekker Inc., New York, pp
147e215.
Bhattacharya, P., Jacks, G., Ahmed, K.M., Khan, A.A., Routh, J., 2002b.
Arsenic in groundwater of the Bengal delta plain aquifers in Bangladesh.
Bulletin of Environmental Contamination and Toxicology 69, 528e545.
Cook, J., 1987. Left bank outfall drain stage 1 project scavenger well studies
and pilot project. British Geological Survey.
Datta, D.K., Gupta, L.P., Subramanian, V., 2000. Dissolved fluoride in lower
GangaeBrahmaputraeMeghna river system in Bengal Basin, Bangladesh.
Environmental Geology 39, 1163e1168.
Ding, Z., Zheng, B., Long, J., Belkin, H.E., Finkelman, R.B., Chen, C.,
Zhou, D., Zhou, Y., 2001. Geological and geochemical characteristics of
high arsenic coals from endemic arsenosis areas in southwestern Guizhou
Province, China. Applied Geochemistry 16, 1353e1360.
Ferguson, J.F., Gavis, J., 1971. A review of the arsenic cycle in natural waters.
Water Research 6, 1259e1274.
Finkelman, R.B., Orem, William, Castranova, Vincent, Tatu, Calin A.,
Belkin, Harvey E., Zheng, Baoshan, Lerch, Harry E., Maharaj, Susan V.,
Bates, Anne L., 2002. Health impacts of coal and coal use: possible solutions. International Journal of Coal Geology 50, 425e443.
Greenman, D.W., Swarzenski, W.V., Bennet, G.D., 1967. Groundwater hydrology of Punjab, West Pakistan with emphasis on problems caused by canal
irrigation. U.S. Geological Survey Water Supply Paper, p. 1608-H.
Gupta, S.K., Chen, K.Y., 1978. Arsenic removal by adsorption. Journal of
Water Pollution Control, Federation 50, 493e506.
Jacks, G., Bhattacharya, P., Chaudhary, V., Singh, K.P., 2005. Controls on the
genesis of some high fluoride groundwaters in India. Applied Geochemistry 20, 221e228.
Jahangir, K., Nabeel, A., 2001. What can public health professionals do in promoting rural health service programs. Lahore Journal of Public Health 1,
6e16.
Kramer, J., Snyder, W.H., 1977. Precipitation Scavenging. The National Academies Press, US, pp. 127e136.
Lee, J.D., 1991. Concise Inorganic Chemistry. Chapman and Hall, Inc., London.
Laura, V., Neus, O., Albert, S., Angels, C., 2004. Fertilizer characterization:
isotopic data (N, S, O, C and Sr). Environmental Science and Technology
38, 3254e3262.
Li, X.D., Masuda, H., Ono, M., Kusakabe, M., Yanagisawa, F., Zeng, H.A.,
2006. Contribution of atmospheric pollutants into groundwater in the
Northern Sichuan Basin, China. Geochemical Journal 40, 103e119.
Mahmood, S.N., Naeem, S., Siddiqui, I., Khan, F.A., 1998. Studies on physico-chemical nature of ground water of Korangi/Landhi (Karachi). Journal
of the Chemical Society of Pakistan 19, 42e48.
Mukherjee, A.B., Bhattacharya, P., 2001. Arsenic in groundwater in The Bengal Delta Plain: slow poisoning in Bangladesh. Environmental Reviews 9,
189e220.
Moncaster, S.J., Bottrell, S.H., Tellam, J.H., Lloyd, J.W., Konhauser, K.O.,
2000. Migration and attenuation of agrochemical pollutants: insight from
isotopic analysis of groundwater sulfate. Journal of Contaminant Hydrology 43, 147e163.
Naseem, M., Farooqi, A., Masih, D., Anwar, M., 2001. Investigation of toxic
elements in the ground water of kalalanwala area near Lahore, Punjab,
Pakistan. Abstracts of Geosas III held at Lahore Pakistan September
23e27, 2001.
Newman, L., Forrest, J., 1991. Sulfur isotope measurements relevant to power
plant emission in the Northeastern US. In: Krouse, I.I.R., Grincnko, V.A.
(Eds.), Stable Isotopes. Natural and Anthropogenic Sulfur in the Environment. Case Studies and Potential Applications. Scope 43. Wiley, Chichester, pp. 331e343.
Nickson, R.T., Mcarthur, J.M., Shrestha, B., Kyaw-Myint, T.O., Lowry, D.,
2005. Arsenic and other drinking water quality issues, Muzzaffargarh district, Pakistan. Applied Geochemistry 20, 55e68.
Pickering, W.F., 1985. The mobility of soluble fluoride in soils. Environmental
Pollution (Series B) 9, 281e308.
Rajiv Gandhi National Drinking Water Mission Survey Report 1986, 1993.
Prevention and Control of Fluorosis in India, pp. 66e75.
Sarma, D.R.R., Rao, S.L.N., 1997. Fluoride concentrations in groundwaters of
Visakhapatnam, India. Journal of Environmental Contamination and
Toxicology 58, 241e247.
Schneiter, R.W., Middlebrooks, E.J., 1983. Arsenic and fluoride removal
from groundwater by reverse osmosis. Environment International 9,
289e292.
Skjelkvsle, B.L., 1994. Factors influencing fluoride in Norwegian lakes. Water
Air and Soil Pollution 77, 151e167.
Smedley, P.L., Kinniburgh, D.G., 2002. A review of the source, behavior
and distribution of arsenic in natural waters. Applied Geochemistry 17,
517e568.
Smedley, P.L., Nicolli, H.B., Macdonald, D.M.J., Barros, A.J., Tullio, J.O.,
2002. Hydrogeochemistry of arsenic and other inorganic constituents in
groundwaters from La Pampa, Argentina. Applied Geochemistry 17,
259e284.
Sexena, V.K., Ahmed, S., 2003. Inferring the chemical parameters for the dissolution of fluoride in groundwater. Environmental Geology 43, 731e736.
Tasneem, M.A., 1999. Impact of agricultural and industrial activities on
groundwater quality in Kasur Area. The Nucleus. Quarterly Journal of
the Pakistan Atomic Energy Commission 36.
The News, Jung, The Nation and The Dawn, daily News paper, Pakistan, 22
July 2000.
A. Farooqi et al. / Environmental Pollution 145 (2007) 839e849
Wang, X.C., Kawahara, K., Guo, X.J., 1999. Fluoride contamination of
groundwater and its impacts on human health in Inner Mongolia area.
Journal of Water Services Research and Technology e Aqua 48, 146e153.
WAPDA-EUAD(Water and Power Development Authority, Environment and
Urban Affairs Division), Booklet on Hydrogeological Map of Pakistan,
1:2, 000, 00 Scale, 1989. WAPDA-EUAD (Lahore Government of
Pakistan).
Wenzel, W., Blum, W.E.H., 1992. Fluoride speciation and mobility in fluoride
contaminated soil and minerals. Soil Science 153, 357e364.
849
Yanagisawa, F., Sakai, H., 1983. Preparation of SO2 for sulfur isotope ratio
measurements by thermal decomposition of BaSO4eV2O5eSiO2
mixtures. Analytical Chemistry 55, 985e987.
Zheng, B., Yu, X., Zhand, J., Zhou, D., 1996. Environmental geochemistry of
coal and arsenic in Southwest Guizhou, P.R. China. 30th International
Geological Congress Abstracts 3, 410.
www.pcrwr.gov.pk/Arsenic, 10 September 2005.
www.brc.cr.usgs.gov/projects/gwc_coupled/phreeqc/, 6 July 2005.
www.cgag.uct.ac.za/limsc/presentations, 2 September 2005.