Fluoride and Arsenic Exposure Through Water and Grain Crops in Nagarparkar, Pakistan ⇑ Kapil D

Chemosphere 100 (2014) 182–189

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Fluoride and arsenic exposure through water and grain crops in Nagarparkar, Pakistan ⇑ Kapil D. Brahman a,1, Tasneem G. Kazi a, , Jameel A. Baig a,1, Hassan I. Afridi a,1, Abdullah Khan b,2, Sadaf S. Arain a,1, Muhammad B. Arain c

a National Center of Excellence in Analytical Chemistry, Department of Analytical Chemistry, University of Sindh, Jamshoro, Sindh 76080, Pakistan b Department of Chemistry, University of Balochistan, Quetta, Pakistan c Chemistry Department, Abdul Wali Khan University, Mardan, Pakistan

highlights graphical abstract

Simultaneously evaluated the contamination of F and arsenic in surface water. Total and bio-available F and arsenic in soil. F and arsenic contents in grain crops and their bio-concentration factor. Estimated daily intake and risk assessment of F and arsenic in different age groups.

article info abstract

Article history: The aim of present study was to simultaneously estimate the arsenic (As) and ﬂuoride (F) concentrations Received 28 May 2013 in irrigated surface water, soil and grain crops of Nagarparkar, Pakistan during 2010–2012. The As and Received in revised form 11 October 2013 F were analyzed by hydride generation atomic absorption spectrometer and ion selective electrode, Accepted 9 November 2013 respectively. Total arsenic (AsT) and F in irrigated surface water samples were found in the range of Available online 14 December 2013 1 1 360–683 lgL and 18.5–35.4 mg L , respectively. While AsT and F concentrations in agriculture soil samples were observed in the range of 110–266 and 125–566 mg kg1, respectively. The water extract- 132;parkar able As and F were found 3–4% of total concentration of these in soils. Keywords: The AsT concentration was higher in kidney been (KB) as compared to pearl millet (PM) and green gram Arsenic (GG), whereas GG had higher F levels as compared to other two grain crops (p < 0.05). The KB samples Fluoride grown in nine sites shows BCF of As in the range of 0.018–0.038. The GG has higher BCF of F as compared Bioaccumulation factor to KB and PM (p < 0.05) grown in all sites. The exposure dose and risk factor of As and F were obtained by Estimated daily intake estimated daily intake (EDI) and hazardous index (HI). It was found that all understudy age groups were Nagarparkar at the severe risk of arsenicosis and ﬂuorosis, but the severity is higher in younger age group (7–15 years) as compared to elder groups (p < 0.05). Ó 2013 Elsevier Ltd. All rights reserved.

⇑ Corresponding author. Tel.: +92 022 2771379; fax: +92 022 2771560. E-mail addresses: [email protected] (K.D. Brahman), [email protected] (T.G. Kazi), [email protected] (J.A. Baig), [email protected] (H.I. Afridi), [email protected] (A. Khan), ssadiashaﬁ@gmail.com (S.S. Arain), [email protected] (M.B. Arain). 1 Tel.: +92 022 2771379; fax: +92 022 2771560. 2 Tel.: +92 081 9211266; fax: +92 081 9211232.

1. Introduction can be leach out and dissolved in groundwater (Laghari, 2005). However, no resulted data are present about the translocation of The high levels of As and F in environmental samples (soil, F and As from growing media to plants and adverse impact on lo- water, biota, etc.) may create health risks to human and animals cal population as per our knowledge. (Naseem et al., 2010). As naturally occurs as inorganic and organic Therefore, the current study has been designed to evaluate the forms in different environmental and biological samples. Inorganic F and As levels in surface water, soil (total and extractable) and As is mostly observed in groundwater, surface water, soil and var- grain crops grown on agricultural lands of Nagarparkar, subdistrict ious foods (Kazi et al., 2009). The contamination of drinking water of Tharparkar, Pakistan. The bio-concentration factor of AsT and F with As become a major health concern and have adverse health in grain crops and the correlation of these elements between effects, as reported in literature (Mandal and Suzuki, 2002; Chak- grains, soils and water were carried out. The hazardous index of raborti et al., 2003; von Ehrenstein et al., 2005; Lubin et al., 2007). AsT and F as well as the individual and cumulative estimated daily As can be transported to plants from air, water and soil (Mahzuz intake (EDI) of AsT and F were also calculated in three age groups et al., 2009; Reza and Singh, 2010). The uptake of As by plants may (7–15, 16–25 and 26–50 years) The influence of different factors, depend on the species of plant and its concentration in particular i.e., AsT and F concentration in surface water/grain crops, period agricultural soils and irrigated water. The scientists have reported of water consumption, age and body mass index were investigated that the concentration of As in cereals, vegetables and fruits is di- in detail. rectly depend upon the level of As in the growing media (Duker et al., 2005; Goyal et al., 2008; Feng et al., 2009; Malakootian et al., 2009; Urík et al., 2009; Kazi et al., 2009). Severe As contam- 2. Material and methods ination in soils may cause its toxicity in plants, animals and human (Warren et al., 2003). The natural releases of As from aquifer rocks 2.1. Description of study area have been identified in many parts of the world (Smedley and Kinniburgh, 2002). Consumption of As contaminated drinking Thar Desert is the southeastern part of Sindh province, Pakistan water is the primary route of exposure for human and animals (Fig. 1) and consists of Tharparkar district, which is administra- (Ohno et al., 2007). Natural level of As in soil usually range from tively divided into four sub-districts. Nagarparkar sub-district is 1.0 to 40.0 mg kg1, with a mean of 5.0 mg kg1, although much situated in the south east extremity of the vast Thar Desert and 0 0 higher levels may occur in mining areas, at waste sites, near high lie in between latitude 24°21.734 –24°36.952 °N and longitude 0 0 geological deposits of As rich minerals, or due to the application 70°39.490 –70°45.192 °E(Rafique et al., 2004; Brahman et al., of pesticides (Mandal and Suzuki, 2002). In different areas of Paki- 2013a). Thari people are economically poor. They have inadequate stan people are facing the As related severe public health disasters education, health and other basic facilities of life. Peoples of this as reported in neighboring countries (Mandal and Suzuki, 2002; area rely on the groundwater and stored rain water for drinking, Smedley and Kinniburgh, 2002; Brahman et al., 2013a,b). livestock and agriculture purposes (Rafique et al., 2004). Fluoride (F) is an essential micronutrient for human beings, The main occupations of local peoples are cattle farming and serving to strengthen the apatite matrix of skeletal tissues and agriculture. In understudy region there is no any proper canal sys- teeth (Maithani et al., 1998). On the other hand, high F tem, only rain water are stored in big ponds and used for agricul- (>1.5 mg L1) results in dental and skeletal fluorosis; renal and ture purposes. The Kharif crops are main agricultural production neuronal disorders along with myopathy (Ayoob and Gupta, of Thar region grown before monsoon season (June and July). The 2006). F is a lithophile element with atmophile affinities, and oc- grain crops include kidney beans (Phaseolus vulgaris), pearl millet curs in many common rock-forming minerals. Therefore, high F (Pennisetum glaucum) and green gram (Vigna radiate) are harvested concentrations in water are expected in areas where fluorine-bear- in the month of September. ing minerals are abundant in the geologic substrate (Tirumalesh A general nutritional survey was carried out. Five households et al., 2006; Shaji et al., 2007; Naseem et al., 2010). were selected from each designated sites (N1–N9). The food habits, Human beings are exposed to F through drinking water, foods and dentifrices. The disease ‘fluorosis’ has now become a global problem and more than 200 million people worldwide are at the risk of fluorosis (UNICEF, 1999). Endemic fluorosis develops widely in many areas of the world, such as China, India and Mexico (Car- rillo-Rivera et al., 2002; Gupta et al., 2005; Guo et al., 2007). It was reported previously that the groundwater of Thar Desert, Pakistan is highly contaminated with fluoride (Rafique et al., 2008). The high concentrations of As and F were investigated in underground water and the enrichment of these elements are due to presence of calcite, fluorite, coal and granite minerals in understudy area (Brahman et al., 2013a). The pollution by F and As are mainly due to coal combustion, causes serious health hazards over large areas of southern China, Inner Mongolia and Pakistan (Finkelman et al., 2002; Smedley et al., 2002; Farooqi et al., 2007; Brahman et al., 2013a,b). The atomic absorption spectrometric technique has been widely used for determination of As at trace levels and other elements, such as electrothermal atomic absorption spectrometry and hydride generation atomic absorption spectrometry (Ghaedi et al., 2013). It is reported in earlier work the granite of the present studied area contains abundant F bearing minerals, and during weathering, F Fig. 1. Map of study area (Nagarparkar-Pakistan). 184 K.D. Brahman et al. / Chemosphere 100 (2014) 182–189 frequency of eating common major grain crops such as kidney Elmer Model 700 (Norwalk, CT, USA) atomic absorption spectrom- beans, pearl millet and green gram in different age groups (7– eter, equipped with a deuterium background corrector, MHS-15 15 years), (16–25 years) and (25–50 years) were assessed and their hydride generation system was used for the As analysis. The oper- average body weights were measured as 25, 50 and 60 kg, respec- ating parameters for working of As hollow cathode lamp were set tively. All parameters including intake frequency indicated just an as recommended by the manufacturer and reported in previous assumption based on selected subjects and taken the mean values. work (Shah et al., 2009). However, these figures may change with the change in socio-eco- nomic conditions of the villagers. The survey was based on the 2.5. Procedure questionnaire and is not a bio-medical research in which human subjects are administered some medicine, injection or chemicals 2.5.1. pH of water and soil samples to study toxicity symptoms. For pH measurement, water samples were filtered while for soil samples, ultra pure water at the ratio (1:2.5) were added and kept 2.2. Sampling overnight at room temperature, then filtrated the suspension through a Whatman 42 filter paper (Jamali et al., 2008a,b). The surface water of ponds (n = 30), soils and grains crops were collected simultaneously from different agricultural fields of 2.5.2. Total As in surface water samples Nagarparkar (N1–N9). The collected surface water were filtered The surface water samples were diluted up to 50 times with through a 0.45 lm membrane filter and divided into two sub-sam- deionized water. The diluted samples were filtered and kept at ples. One sub-sample was acidified with HNO3 (0.2% v/v) for the 4 °C till further analysis as reported in previous works (Arain analysis of As concentrations, while the other was remain un-acid- et al., 2009; Baig et al., 2010a,b). ified for the determination of pH and F. The water samples were kept in well stoppered polyethylene plastic bottles previously 2.5.3. Microwave acid digestion method for total As in soil and grain soaked in 10% HNO for 24 h and rinsed with ultra pure water. 3 crop samples All water samples were stored in insulated cooler containing ice, Total As concentrations in soil and grain crops samples were delivered on the same day to laboratory and kept at 4 °C until pro- performed using wet acid digestion in a microwave oven. Duplicate cessing and analysis. 0.1 g of each soil and 0.2 g of dried ground grain samples were Surface soil (0–25 cm) and grain samples were collected simul- placed separately in acid washed PTFE flasks (25 mL in capacity). taneously from nine agricultural sites. Soil samples were collected Soil samples and grain crops were treated with 10 mL of HCl:HNO by inserting a 37.5 mm diameter PVC pipe sampler (about 750 mm 3 (3:1) and 2 mL of H O :HNO (1:2), respectively. Place these flasks in height) into the soil. After withdrawing the sampler along with 2 2 3 in a PTFE container separately (for both samples) then heated fol- the soil core, it is both ends were sealed with tapes to reduce con- lowing a one-stage digestion programme (80% of total power tact with air and transported to the laboratory. The soil samples 900 W), 5 min for soil and 2 min required for grains. After cooling, were spread on plastic trays in fume cupboard and air dried for the extra acid was evaporated to obtain a semidried mass. Added 8 d at room temperature. Each grain samples were put through a 10 mL of 0.1 M HNO to all digests and filtered through Whatman three step washing sequence, agitating and rinsing twicely with ul- 3 42 filter paper. The sample solution made up to 25 mL in volumet- tra pure water. The washed grain samples were air dried, weighed ric flask with ultrapure water. Blank extractions (without sample) and placed in an electric oven at 70 °C for 48 h. The dried soil and were carried out throughout the complete procedure and analyzed grain samples were homogenized by grinding in an agate mortar by HGAAS. and sieved through a nylon sieve <100 lm mesh size. The final samples were kept in labeled polypropylene containers at ambient 2.5.4. Total F contents of surface water samples temperature before analysis. The F concentrations was determined in surface water samples by ion selective electrode (Malde et al., 1997). 2.3. Chemicals and glassware

Ultrapure water obtained from ELGA lab water system (Bucks, 2.5.5. Total F contents in grain and soil samples UK) was used throughout the work. All chemicals and reagents Triplicate composite soil samples of each site (1.0 g) were are analytical grades. Ethylenediaminetetraacetic acid (EDTA), ni- weighed into 70 mL ceramic crucibles, covered with 5 mL of 5 M NaOH solution, and heated on a hot plate (150 °C). The slurries tric acid (HNO3), hydrogen peroxide (H2O2), sulfuric acid (H2SO4), hydrochloric acid (HCl), potassium hydroxide (KOH) and Sodium were evaporated to dryness; one pellet of sodium hydroxide was hydroxide (NaOH) were purchased from Merck (Darmstadt, Ger- added and covered the crucibles. Subsequently, these are placed many). Calibration standards were prepared for certified stock in a muffle furnace (560 °C) for 2 h. After cooling, deionized water standard solution of As 1000 lgL1, (Fluka). Reducing agents, 3% was added and the crucibles were heated on a hot plate (100 °C) to (m/v) sodium tetrahydroborate acros organics (New Jersey, USA) aid dissolution of the fusion cake. The pH of sample solutions was in 1% NaOH, were prepared freshly and filtered before use. The adjusted at 5.3 with a buffer system before analyzing F by ion pH of the sample solution was adjusted with 0.1 M HCl/0.1 M selective electrode (Malde et al., 1997). NaOH. The working standards of F were prepared from Fluoride Standard solution (0.1 M) of sodium fluoride (NaF) (Radelkis Elec- 2.5.6. Water soluble F contents in soil trochemical Instruments, Hungary). All the glassware were kept Triplicate samples of soil (2 g) was weighed into a conical flask, overnight in 5 M HNO3, rinsed with deionized water before used. and mixed with 10 mL of distilled water. The mixture was shaken for 2 h at 120 rpm, allowed to stand for 1 h and the suspension fil- 2.4. Instruments tered through a Whatman 42 filter paper (Vike, 2005).

The pH was measured by a pH meter (781-pH meter, Metrohm). 2.6. Exposure dose determination Mechanical shaker (Gallankamp, England) was used for shaking. Ion meter 781 Metrohm (Herisau, Switzerland) with ion selective The quantitative health risk assessment was measured by electrode (ISE, Metrohm) employed for fluoride analysis. A Perkin assessing the exposure doses of As and F due to the consumption K.D. Brahman et al. / Chemosphere 100 (2014) 182–189 185 of studied grain crops and drinking water in terms of estimated 2.8. Quality control daily intake (EDI) using a generic equation (USEPA, 1992). The EDI can be calculated as: Calibration was performed with a series of As standards. Sensi- tivity (m) was the slope value obtained by least-square regression EDI ¼ðC IR EF ED AF CFÞ=ðBW ATÞ analysis of calibration curves based on peak area measurements. where EDI is the estimated daily intake (mg kg1 d1), C the con- The equation (n = 5) for the calibration curves were as follows: 1 centration of As/F in grain crops (mg kg ), IR the ingestion or in- 3 1 1 Y ¼ð0:187 0:008Þ½Asþð4:6 10 0:0001Þ take rate (mg d ), EF the exposure frequency (d year ), ED the exposure duration (year), AF the absorption factor (unit less), CF where Y is integrated absorbance, [As] is the As concentration in 6 1 the conversion factor (10 kg mg ), BW the body weight (kg) lgL1, the calibration curve obtained from the quantification limit and AT the averaging time (d). Here the absorption factor was taken up to 10 lgL1. The limit of detection (LOD), was defined as as 75%. Whereas, EDI based on drinking water was calculated as: 3 sm1, ‘s’ being the standard deviation corresponding to 10 C IR EF ED blank injections and ‘m’ the slope of the calibration graph equal to EDI ¼ 0.12 lgL1, the limit of quantification (LOQ), defined as 10 sm1. BW AT The LOD and LOQ of As were found as 0.12 and 0.42 lgL1, respec- But here, C is the concentration of AsT/F in drinking water tively. The calibration graph for F was obtained by ion selective 1 1 (mg L ) and IR the ingestion or intake rate (L d ). However, other electrode with the calibration range of 1.0–10.0 mg L1, obtained parameters were same as above. The water ingestion rate was slope value was m = 60.3 mV. The LOD and LOQ of F were calcu- determined by asking the question ‘‘How many glasses of water lated as 6.0 and 20.0 lgL1, respectively. do you drink per day? Most households use the same size (250 mL) and style of glasses. This assumption was made because with the consumption of GC or drinking water would increase 3. Results and discussion the EDI to a greater extent. The site specific cumulative EDI was also calculated in the study area as follows: 3.1. Arsenic and fluoride in water samples

EDICumulative ¼ EDIgrain crops þ EDIwater The resulted data of surface water were based on nine sampling sites, during July to September in 2011–2012. The pH was found predominantly neutral to slightly alkaline (pH 7.6–8.7), which is 2.7. Risk assessment within the WHO recommended values (6.5–9.0). The AsT and F content in surface water of nine sampling sites were found in the The assessment of risk due to As/F exposure dose (EDI) in var- range of 360–683 lgL1 and 18.5–35.4 mg L1, respectively ious age groups was also carried out by comparing with the refer- (Table 1). The concentration of AsT and F were 36.0–68.0 and ence dose of As/F by determining the hazard index (HI), which is 18.0–35.0 times greater than permissible limit of AsT and F in deﬁned as the ratio of cumulative EDI to the reference dose (RfD), drinking water, respectively. The average concentration of AsT in represents As/F intake risk: surface water samples was found to be 449 lgL1, which is higher

HI ¼ EDICumulative=Rf D than reported values for surface water (Kahlown et al., 2002; Mukherjee et al., 2005; Rapant et al., 2006; Arain et al., 2009). RfD is the reference dosage (oral toxicity reference value). It is 3.04E04 and 0.06 mg kg1 d1 for As and F, respectively. 3.2. Total and extractable arsenic and ﬂuoride in soil samples

Table 1 The pH value of agricultural soil samples collected during study pH, total arsenic and fluoride in surface water samples of Nagarparkar Sindh– period were found in the range of 7.5–8.2. The concentrations of Pakistan. AsT and F in all understudy agricultural soil samples were ob- 1 1 -1 Sample I.D pH AsT (lgL )F(mg L ) served in the range of 110–266 and 125–566 mg kg , respectively. N-1 7.5 ± 0.2 360.0 ± 12.4 18.5 ± 1.1 The normal range for AsT in soils of various countries was 0.1– -1 N-2 8.6 ± 0.4 516.0 ± 19.7 27.3 ± 1.0 40.0 mg kg (Das et al., 1995). It was predicted by a conservative N-3 8.2 ± 0.3 410.0 ± 11.9 22.9 ± 0.8 risk analysis that AsT level in the soil could reach 4.0 mg/kg with- N-4 8.5 ± 0.3 450.0 ± 24.1 24.3 ± 0.7 out becoming a hazard to the exposed organisms (Das et al., 1995). N-5 7.9 ± 0.2 389.0 ± 7.8 20.1 ± 0.8 Thus, US EPA set a criterion for AsT contents in the soil as 2.0– N-6 8.6 ± 0.4 580.0 ± 26.4 31.7 ± 1.1 1 N-7 8.4 ± 0.3 433.0 ± 22.2 23.8 ± 0.7 5.0 mg kg (Smedley and Kinniburgh, 2002). Our finding indicated N-8 7.8 ± 0.3 380 ± 19.1 19.8 ± 1.0 that the soil samples collected from different agricultural plots irri- N-9 8.7 ± 0.4 683.0 ± 28.1 35.4 ± 1.3 gated with surface water were significantly exceeded the maxi-

mum permissible level for AsT in soil (Table 2).

Table 2 1 pH, AsT, water extractable As, EDTA extractable As, total F and water extractable F in soil of Nagarparkar Sindh, Pakistan (mg kg ).

Sample I.D pH AsT Water extractable As EDTA extractable As F Water extractable F N1 7.7 ± 0.4 110.0 ± 4.5 3.5 ± 0.2 8.9 ± 0.6 125.0 ± 6.8 4.4 ± 0.2 N2 7.6 ± 0.4 183.0 ± 5.8 5.1 ± 0.2 16.1 ± 0.7 278.0 ± 6.6 3.9 ± 0.3 N3 7.7 ± 0.3 198.0 ± 5.2 5.7 ± 0.2 17.0 ± 0.6 222.0 ± 10.4 4.9 ± 0.3 N4 7.7 ± 0.2 200.0 ± 2.7 6.6 ± 0.1 16.2 ± 0.4 172.0 ± 4.2 5.7 ± 0.5 N5 8.2 ± 0.6 153.0 ± 8.9 4.4 ± 0.4 11.9 ± 1.1 152.0 ± 4.2 8.3 ± 0.6 N6 7.8 ± 0.3 200.0 ± 2.7 6.6 ± 0.1 16.2 ± 0.4 251.0 ± 9.3 5.7 ± 0.5 N7 7.5 ± 0.3 205.0 ± 7.6 7.0 ± 0.3 19.3 ± 1.0 566.0 ± 11.3 12.1 ± 0.4 N8 7.7 ± 0.4 170.0 ± 6.2 5.1 ± 0.2 14.3 ± 0.8 135.0 ± 5.9 8.9 ± 0.8 N9 7.8 ± 0.3 266.0 ± 7.5 8.3 ± 0.3 23.4 ± 0.9 503.0 ± 13.4 18.6 ± 1.5 186 K.D. Brahman et al. / Chemosphere 100 (2014) 182–189

The bio-availability of AsT from agricultural soil to plants pro- The levels of similarity of observations are merged and used to vided the knowledge about the potential risk of As for plants, ani- construct a dendogram (Chen et al., 2007). The resulted group mals and human beings. Therefore, it is necessary to evaluate the shown in dendogram (Fig. 2), based on the results of AsT and F mobile and/or the available fractions of AsT in soil (Baig et al., in soil and surface water of studied sites. According to resulted 2011). Many researchers have tried to find a way of measuring data all sites were grouped into three statistically significant clus- the plant available fraction of elements in soils using different ters. The dataset was treated by the Ward’s method of linkage with extraction procedures (Smedley and Kinniburgh, 2002; Jamali squared Euclidean distance as measure of similarity. The sampling et al., 2006, 2008a,b). These methods have been validated in field sites N-1, N-5 and N-8 made one group as cluster-1. The surface experiments by correlating the AsT contents in plants with extract- water samples of sites in cluster-1 contained AsT and F in the con- able soil contents. The analysis of water extractable soil is widely centration range of 360–389 lgL1 and 18.5–20.5 mg L1, respec- used in agriculture, for the prediction and assessment of elements tively. The AsT and F in soil were found in the range of 110–170 deficiency or toxicity to crops or animals (Mir et al., 2007). and 125–152 mg kg1, respectively. Due to mutual dissimilarity The analytical results of total and water extractable As in soil among other sampling origins made of cluster-2, (N-2, N-3 and are expressed on dried weight basis as shown in Table 2. The water N-4 sites), contains AsT and F in surface water samples in the con- extractable As and F were observed in the range of 3.5–8.2 and centration range of 410–516 lgL1 and 22.9–27.3 mg L1, respec- 1 3.9–18.6 mg kg , respectively. Most of the F in the soil is insolu- tively. The soil samples of cluster-2 have AsT and F in the range of ble, therefore less available to plants. The capacity for a plant to ab- 183–200 and 172–278 mg kg1, respectively. The cluster-3, in- sorb As and F from the soil will also depend on the species of plant volved N-6, N-7 and N-9 sites, contains AsT and F in surface water and, to some extent on As and F available form (water extract- samples in between 433–683 lgL1 and 23.8–35.4 mg L1, respec- able) (Stevens et al., 1998; Okibe et al., 2010). tively, while the AsT and F in soil samples were found in the range of 200–266 and 251–566 mg kg1, respectively. Sample sites (clus- 3.3. Cluster analysis ter-3) shows the higher concentrations of AsT and F . A significant positive correlation was found between AsT and F concentrations The resulted data in cluster analysis are grouped such that the in all understudy water and soil samples (r = 0.732–0.812). similar objects fall into the same class (Danielsson et al., 1999). 3.4. Total arsenic and fluoride in grain crops

The result of the current study and previously reported work had shown that AsT and F deposits in the tissues of plants grown in As/F rich soil and irrigated water (Gulati et al., 1993; Singh et al., 1993; Bae et al., 2002; Duxbury et al., 2003; Khandare and Rao, 2006; Rahman et al., 2008; Baig et al., 2011). The contents of As in the edible parts of plants were generally low as compared to root and shoots (Smedley and kinniburgh, 2002). However, the population of understudy areas is poor and mainly depends upon locally grown grain crops used as a cereal. Therefore, for current study only the edible parts (grains) of grain crops were investigated for AsT and F contents. The As and F concentrations in grain crops such as KB, PM and GG were determined and are pre- sented in Table 3. It was found that As concentration was higher in KB as compared to PM and GG, whereas GG had higher F levels as compared to other two grain crops, although they grown in same Fig. 2. Dendrogram showing clustering of different sites of surface water and soil agricultural sites (Table 3). However, there is not adequate infor- according to distribution of As and F . mation on the nature of AsT and F in food materials. The possibil-

Table 3 1 Concentration mean ± standard deviation (mg kg ) and bio-concentration factor (BCF) of AsT and F in grains crops grown in different agriculture plots.

Sample I.D. KB BCF PM BCF GG BCF

AsT N-1 4.18 ± 0.21 0.038 1.99 ± 0.10 0.018 2.68 ± 0.13 0.024 N-2 4.54 ± 0.31 0.023 3.39 ± 0.14 0.017 3.44 ± 0.23 0.017 N-3 4.69 ± 0.32 0.021 4.34 ± 0.15 0.019 4.09 ± 0.19 0.018 N-4 4.27 ± 0.24 0.028 2.06 ± 0.12 0.013 2.81 ± 0.16 0.018 N-5 4.31 ± 0.23 0.025 2.44 ± 0.11 0.014 3.11 ± 0.18 0.018 N-6 4.38 ± 0.25 0.024 2.94 ± 0.17 0.016 3.28 ± 0.21 0.018 N-7 4.62 ± 0.34 0.023 3.88 ± 0.16 0.019 3.62 ± 0.27 0.018 N-8 4.65 ± 0.29 0.023 4.15 ± 0.19 0.020 3.88 ± 0.25 0.019 N-9 4.73 ± 0.35 0.018 4.62 ± 0.21 0.017 4.29 ± 0.24 0.016 Sample I.D. KB BCF PM BCF GG BCF F N-1 26.31 ± 1.32 0.210 21.20 ± 1.76 0.170 146.20 ± 7.80 1.170 N-2 31.90 ± 1.60 0.056 25.90 ± 2.10 0.046 164.00 ± 8.40 0.290 N-3 35.66 ± 1.78 0.080 29.40 ± 2.01 0.066 179.50 ± 9.40 0.402 N-4 27.64 ± 1.38 0.125 22.60 ± 1.56 0.102 151.40 ± 7.92 0.682 N-5 28.76 ± 1.44 0.213 23.30 ± 1.46 0.173 156.20 ± 8.15 1.157 N-6 29.87 ± 1.49 0.107 24.70 ± 1.94 0.089 159.70 ± 8.20 0.574 N-7 34.76 ± 1.73 0.138 27.70 ± 2.08 0.110 172.30 ± 9.12 0.686 N-8 33.24 ± 1.66 0.219 26.80 ± 2.14 0.176 167.90 ± 8.60 1.105 N-9 36.88 ± 1.84 0.073 31.50 ± 1.86 0.063 181.20 ± 9.50 0.360 K.D. Brahman et al. / Chemosphere 100 (2014) 182–189 187

ity of the presence of organic or tightly bound AsT and F in food materials remain to be veriﬁed (Khandare and Rao, 2006; Baig

et al., 2011). 2

Bio-concentration factor for AsT:F were calculated for studied grain crops, KB (0.018:0.056 to 0.038:0.219), PM (0.013:0.046 to 0.020:0.176) and GG (0.016:0.290 to 0.024:1.170), results are shown in Table 3. The KB sample grown in site N-1 shows high

BCF of As (0.038) and minimum (0.018) was predicted at site N- 2 1.9E 9. The estimated BCF for AsT was lower than 0.025 in all samples of KB, PM and GG, except KB samples of locations N-1 and N-4. The resulted data also showed signiﬁcantly higher BCF values for F in GG samples of sites N-1, N-5 and N-8 as shown in Table 3 2 2.3E (p 6 0.05). The minimum value of BCF of F was observed in PM sample of site N-2 (0.046). However, the BCF values for F were signiﬁcantly higher in all studied grain crops (p 6 0.05). It was observed that the BCF decreased with the increase of AsT and F con-

centrations in the media, which may imply the restriction in soil- 2 2.7E root transfer at higher concentrations of soil. These finding are con- sisting with those reported in literature (Yoon et al., 2006; Ho et al., 2008; Rauf et al., 2011). However, Swartjes et al. (2007) had reported that BCF values are not always constant in specific crops and is largely affected by soil properties like pH, clay content, or- 2 5.4E ganic matter and F concentration in soil and also plant factors like type of plant and growth rate. Moreover, the results (Table 4) shown that the concentration of As in GC was significantly correlated with As and water extract- T 2 6.5E able As. of soil (r = 0.922–0.995), and AsT in water (r = 0.867– 0.937). It was observed that correlation coefficient of As content in grains with water was found to be lower than those values obtained from water extractable and total As contents in soil. While it is reverse in the case of F. The F concentrations in KB, PM and GG were significantly correlated with its levels in water samples (r = 0.945–0.979), which was significantly lower (p < 0.05), than those r values obtained for total and water extractable F in agri- 0.4327.711420129 0.335 6.23 1103 104 0.280 5.20 919 86.6 cultural soil with related to grains of KB, PM and GG (r = 0.620– 0.763).

3.5. Nutritional survey

The nutritional survey among the population of different age groups (7–15 years), (16–25 years) and (26–50 years) was con- ducted in understudy area. The mean intake of grains, KB:PM:GG for the age group of 7–15 was 30:100:15 g d1, while in age groups 16–25 and 26–50 years, it was calculated as 50:150:25 g d1. The 2 0.29 0.22 0.18 7.8E 1 1 mean intake of drinking water in age group 7–15 years was 1 d d 1.5 L d and for age groups 16–25 and 26–50 years was 1 1 2.5 L d1 due to hot weather of understudy area. The consump- and F tion pattern of grain crops and drinking water among population T Unitmg kg mg kg 7–15 years 16–25 years 26–50 years of different age groups was found with wide variation. 2 2.3E

3.6. Exposure dose due to consumption of grain crops and drinking water 2 2.8E

The populations of studied areas were not exposed to As and F only through drinking water, but other routes of exposure, i.e., 30,00030 50,0003.3E 1080.23 100,000 150,000 0.19 182 15,000 0.16 365 25,000 2.30 1.5 1.72 2.5 1.44 3.69 3.07 2.56 1.49 1.24 1.04 7–15 years 16–25 years 26–50 years 7–15 years 16–25 years 26–50 years 7–15 years 16–25 years 26–50 years 7–15 years 16–25 years 26–50 years

Table 4 through grain crops and drinking water in Nagarparkar Sindh, Pakistan. 1 1 1 Pearson correlation coefﬁcient (r)ofAsT and F in soils, water extractable soil and d d 1 1 1

irrigation water with Kidney bean, pearl millet and green gram. and F T

Parameter Kidney bean Pearl millet Green gram T mg kg mg kg

AsT soil 0.927 0.925 0.958 of As of F Water extractable As 0.970 0.973 0.987 T T AsT in water 0.867 0.896 0.937 F soil 0.620 0.667 0.635 Water extractable F 0.701 0.763 0.743 Cumulative Cumulative EDI of F EDI HI of As HI of F EDI EFEDBWATEDI of As d year years kgCumulative estimated daily intake and d hazardous index of As 11 25 4015 20 50 7300 35 12,775 60 11 4015 25 7300 20 50 12,775 35 60 4015 11 7300 25 20 12,775 50 4015 35 60 7300 11 12,775 25 20 50 35 60 IR mg or L d F in water 0.945 0.979 0.959 Parameters Unit KB PM GG Water Table 5 Risk assessment of As 188 K.D. Brahman et al. / Chemosphere 100 (2014) 182–189 dietary As and F intake may be also important. The estimated dai- References ly intake (EDI) of AsT and F through grain crops and drinking water were calculated to assess their exposures in different age Arain, M.B., Kazi, T.G., Baig, J.A., Jamali, M.K., Afridi, H.I., Shah, A.Q., Jalbani, N., Sarfraz, R.A., 2009. Determination of arsenic levels in lake water, sediment, and groups. The mean concentration of AsT and F in grain crops and foodstuff from selected area of Sindh, Pakistan: estimation of daily dietary drinking water can be used to calculate EDI. Information on indi- intake. Food Chem. Toxicol. 147, 242–248. vidual grain crops and drinking water consumption history in Ayoob, S., Gupta, A.K., 2006. Fluoride in drinking water a review on the status and stress effects. Crit. Rev. Environ. Sci. Technol. 36, understudy areas has to be collected by verbal questionnaire, 433–487. based on the interviews of selected people of each site. All param- Bae, M., Watanabe, C., Inaoka, T., Sekiyama, M., Sudo, N., Bokul, M.H., Ohtsuka, R., eters used for the calculation of individual and cumulative EDI of 2002. Arsenic in cooked rice in Bangladesh. Lancet 360, 1839–1840. grain crops and drinking water in three age groups are given in Baig, J.A., Kazi, T.G., Shah, A.Q., Afridi, H.I., Kandhro, G.A., Khan, S., Kolachi, N.F., Wadhwa, S.K., Shah, F., Arain, M.B., Jamali, M.K., 2011. Evaluation of arsenic Table 5. levels in grain crops samples, irrigated by tube well and canal water. Food The individual EDI of KB, PM, GG and drinking water indicated Chem. Toxicol. 49, 265–270. that the age group (7–15 years) had high level of EDI as compared Baig, J.A., Kazi, T.G., Shah, A.Q., Arain, M.B., Afridi, H.I., Khan, S., Kandhro, G.A., Naeemullah, , Soomro, A.S., 2010a. Evaluating the accumulation of arsenic in to elder groups. The individual EDI of grain crops according to age maize (Zea mays L.) plants from its growing media by cloud point extraction. group decreased in the approximate order as: 7–15 years > 16– Food Chem. Toxicol. 48, 3051–3057. Baig, J.A., Kazi, T.G., Shah, A.Q., Kandhro, G.A., Afridi, H.I., Arain, M.B., Jamali, M.K., 25 years > 26–50 years. It was found that cumulative EDI of AsT:F Jalbani, N., 2010b. Speciation and evaluation of Arsenic in surface water and in age group 7–15, 16–25 and 26–50 years were 0.48:8.98, ground water samples: a multivariate case study. Ecotox. Environ. Safe. 73, 1 1 0.34:6.23 and 0.28: 5.20 mg kg d , respectively. The cumulative 914–923. Brahman, K.D., Kazi, T.G., Afridi, H.I., Naseem, S., Arain, S.S., Naeemullah, 2013a. EDI values of AsT and F in age group 7–15 years were found to be 6 Evaluation of high levels of fluoride, arsenic species and other physicochemical higher as compared to the other age groups (p 0.05). parameters in underground water of two sub districts of Tharparkar, Pakistan: a multivariate study. Water Res. 47, 1005–1020. Brahman, K.D., Kazi, T.G., Afridi, H.I., Naseem, S., Arain, S.S., Wadhwa, S.K., Shah, F., 3.7. Risk assessment 2013b. Simultaneously evaluate the toxic levels of fluoride and arsenic species in underground water of Tharparkar and possible contaminant sources: a multivariate study. Ecotox. Environ. Safe. 89, 95–107. The hazard index (HI) was calculated for various age groups Carrillo-Rivera, J.J., Cardona, A., Edmundo, W.M., 2002. Use of abstraction regime in different sites, as shown in table 5. It was found that HI of and knowledge of hydrogeological conditions to control high fluoride concentration in abstracted groundwater San Luis Potosy basin. Mexico. AsT and F in the case of age group (7–15 years) was 1585 Hydrogeol. J. 261, 24–47. and 150, respectively. On the bases of these findings, the rural Chakraborti, D., Mukherjee, S.C., Pati, S., Sengupta, M.K., Rahman, M.M., Chowdhury, population consuming studied grains, KB, PM, GG in addition U.K., Lodh, D., Chanda, C.R., Chakraborti, A.K., 2003. Arsenic groundwater contamination in Middle Ganga Plain, Bihar India: a future danger. 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Silica based on their concentrations [cluster-1 (N-1, N-5, N-8), cluster-2 chemically bonded N-propyl kriptofix 21 and 22 with immobilized palladium (N-2, N-3, N-4) and cluster-3 (N-6, N-7, N-9)]. The estimated BCF nanoparticles for solid phase extraction and preconcentration of some metal ions. Mater. Sci. Eng. C 33 (6), 3180–3189. for AsT was <0.025 in all samples of KB, PM and GG, except KB sam- Goyal, P., Sharma, P., Srivastava, S., Srivastava, M.M., 2008. Saraca indica leaf ples grown in sites N-1 and N-4 (0.028–0.038). The resulted data powder for decontamination of Pb: removal, recovery, adsorbent also showed significantly higher BCF values for F in GG samples characterization and equilibrium modeling. Int. J. Environ. Sci. Technol. 5 (1), 27–34. of sites N-1, N-5 and N-8. The exposure doses of AsT and F ob- Gulati, P., Singh, V., Gupta, M.K., Vaidya, V., Dass, S., Prakash, S., 1993. 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