Republic of Yemen Ministry of Water & Environment National Water Resources Authority

Study about the Fluorosis in

Selected Villages of Ta'aiz

Governorate

Sana'a Juner 2009 Study about the Fluorosis in Selected Villages of Taiz Governorate

Final Draft Mission Report prepared for NWRA by

Dr. Abdulmohsen Saleh Alamry

Assistant Professor

&

Water Resources Consultant

1

Contents

Contents ...... 2

1. Introduction: ...... 4 1.2. Fluorosis in Yemen: ...... 4 1.3 Objectives of Study: ...... 5 1.4 Previous Work:...... 5

2. Fluorosis in Taiz Governorate: ...... 6 2.1 Overview of fluoride distribution of Taiz Districts:...... 6 2.1.1‐ Al Wazeyah District:...... 8 2.1.2‐ Mwoza District:...... 8 2.1.3‐ Maqbanah District:...... 9 2.1.4‐ Mawyah District:...... 9 2.1.5‐ Sharab As Salam District:...... 9 2.1.6‐ Sharab Ar Rownah District:...... 10 2.1.7‐ Dimnat Khadeer District: ...... 10 2.1.8‐ Hayfan District: ...... 11 2.1.9‐ Jabal Habashi District:...... 11 2.1.10‐ Al Mawasit District:...... 12 2.1.11‐ Al Mukha District: ...... 12 2.1.12‐As Salow District:...... 12 2.1.13‐Ash Shammayatain District: ...... 13 2.1.14‐ At Aaiziyah District:...... 13 2.2 Delineation of fluoride contamination areas: ...... 15 2.3 Topography of the affected area: ...... 17 2.4 Climate:...... 17

3. Fluoride Contamination in Groundwater of Al Howban Basin: ...... 18 3.1 Geology of Al Howban Basin:...... 18 3.2 Recharge and Groundwater Conditions: ...... 21 3.3 Hydrochemistry of water:...... 22 3.4 Geochemical modeling: ...... 23 3.5 Special Variation in the Fluoride Concentration:...... 24 3.6 Drinking Water Sources:...... 25

4. Fluoride Contamination in Groundwater of Hidhran & Alburayhi Basin: ...... 28 4.1 Geology of Hidhran & Alburayhi Basin:...... 28 4.2 Groundwater Conditions and Recharge Area: ...... 29 4.3 Hydrochemistry of water:...... 31 4.4 Geochemical modeling: ...... 32

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4.5 Special Variation in the Fluoride Concentration:...... 33 4.6 Drinking Water Sources:...... 36

5. Fluoride Contamination in Groundwater of Jabal Sabir Area:...... 36 5.1 Geology of Jabal Sabir Area: ...... 37 5.2 Recharge and Groundwater Conditions: ...... 39 5.3 Hydrochemistry of water:...... 39 5.4 Geochemical modeling: ...... 40 5.5 Special Variation in the Fluoride Concentration:...... 41 5.6 Drinking Water Sources:...... 43

6. Types of Fluorosis in the Study Area:...... 43 6.1 Dietary Practices of the Children: ...... 43

7. Suggestions for Solutions: ...... 45

8. Conclusions: ...... 46

9. Recommendations: ...... 47

References:...... 49

Appendix 1...... 52

Appendix 2...... 54

Appendix 3...... 66

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1. Introduction: Fluorine is the most electronegative and reactive of all elements, and is present as fluoride in drinking water. It occurs as Fluoride ion naturally in soils and natural waters due to chemical weathering of some F- - containing minerals (Totsche et al. 2000). Fluoride in small amounts is an essential component for normal mineralization of bones and formation of dental enamel (Bell and Ludwig 1970). However, excessive intake of fluoride can cause dental and skeleton fluorosis (Sorg 1978; Mahramanlioglu et al. 2002). Due to its strong electronegativity, fluoride is attracted by positively charged calcium in teeth and bones (Susheela et al. 1993). Fluorosis is a considerable health problem worldwide, which is afflicting millions of people in many areas of the world, for example East Africa (Nanyaro et al. 1984; Gaciri and Davies 1993; Gizaw 1996), Turkey (Oruc 2003), India (Subba Rao and Devadas 2003; Gupta et al. 2005, Jacks et al. 2005), southeastern Korea (Kim and Jeong 2005) and northern China (Wang and Reardon 2001; Zhang et al. 2003; Guo et al. 2007). According to World Health Organization (WHO) Guidelines for Drinking Water Quality (WHO 2006) the limit value for fluoride is 1.5 mg/l. The value of 1.5 mg/l is a guiding value, which may be changed based on climatic conditions like temperature, humidity, volume of water intake, fluoride from other sources etc for different regions of the world (Viswanatham, 2008). The Yemeni Standard specifies the desirable and permissible limits for fluoride in drinking water as 1.0 and 1.5 mg/l, respectively.

1.2. Fluorosis in Yemen: Fluorosis continues to be an endemic problem in Yemen. More and more areas are being discovered regularly that are affected by fluorosis in different parts of the country. Children in the age group of upto 12 years are most prone to fluorosis as their body tissues are in formative / growth stage during this period. Recently, a report from General Authority of Rural Water Projects (GARWP) indicates markedly increasing in fluoride content in groundwater (Between 2000 and 2006) in districts of some governorates such as Sana’a, Ibb, Dhamar, Taiz, Al-Dhalei and Raimah. The highest fluoride concentration in drinking water was reported in some districts of Sana'a governorate, especially Sanhan (UNICEF, 2008).

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Most Yemenis dwelling in rural areas use deep well water for drinking and household works—and a large number of these wells are contaminated with fluoride in a concentration of 2.5 to 32 milligrams (Viswanatham, 2008). Fluorosis, especially the skeletal one is historically unknown in Yemen. It is known only about 2 to 3 years reported back and of recent findings. Clinically, it's developed due to the concentration of fluoride in bones. However, dental fluorosis is not new in Yemen, especially in Taiz governorate. .

1.3 Objectives of Study: The main objectives of the study are described in the TOR (Appendix 1). The TOR focus on the fluorosis study in selected villages of Taiz, through the collection of baseline data on the fluoride contamination and delineate the villages affected by fluorosis. Among the other objectives is to study the source of fluoride in drinking water of the affected areas through the development of hydrogeochmical data modeling. Accordingly, the first step of the work has been to collect and analyze all previous studies related to fluoride concentrations, fluorosis and hydrogeology of the affected villages in Taiz governorate.

1.4 Previous Work: Unfortunately there are no reports or published literature available on fluoride and fluorosis aspects of Taiz area. However, some of hydrogeological and groundwater quality studies in the form of unpublished reports about some basins in Taiza Governorates are available in NWRA/Taiz, which are focusing on Taiz city water supply. Hydrogeological and land use study have been carried out by Dar El-Yemen (DEY) during 1996. A set of technical field study activities and laboratory analysis were carried out in the upper Wadi Rasyan catchment area where they have presented some of wells having high fluoride concentrations. A hydrochemical and pollution study

5 was conducted in the upper Wadi Rasyan by the Dutch student within the scope of the DEY & SOAS study (van der Welle, 1997). The technical report prepared and collected from NWRA/Taiz (2006) about quality of groundwater in Al-Howban catchment area was the first report mentioned the fluoride contamination problem in Al-Howban area. On the other hand, a technical report on quality of water in Hidhran and Al Burahay basin prepared by NWRA/Taiz (2008) was collected, where they have presented the analysis of high fluoride contamination in this area. The data of the two reports were collected, analyzed and considered to be the important key data source available on fluoride in the study area.

2. Fluorosis in Taiz Governorate:

2.1 Overview of fluoride distribution of Taiz Districts: Taiz governorate consists of seventeen districts (recently six more districts added to Taiz) and the location of every district is given in Fig.1. One objective of the present study is to identify the villages affected by fluorosis and to prepare a flourosis endemic areas map for Taiz Governorate. In order to meet this objective, it's felt necessary to assemble the previously collected hydrochemical data from the related government offices in Taiz. Hence, information about the chemical analysis of drinking water of Taiz districts has been collected from GARWP/Taiz and NWRA/Taiz. Out of the seventeen districts of Taiz Governorate, data about the chemical analysis of drinking water of fourteen districts has been found in GARWP/Taiz and collected. The chemical analysis of every district was prepared in separate table and evaluated from the point of view of fluoride concentration as following:

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Fig.1: Taiz Administrative Map 1540000 280000 300000 320000 340000 360000 380000 400000 420000 440000 460000 1540000 1520000

Sharab Ar Rownah Sharab As Salam N 1520000 1500000 At Taiziyah Mowyah Maqbanh 1500000 Sabir

Jabal M 1480000 is Almukha Habashi ra kh Dim nat Khaceer

1480000 Al Mawasit As Salam

Mowza 1460000 Hayfan

Ash sham mayatain

1460000 Alwazeyah 1440000 Dhubab 1440000 1420000

1420000 0 10 20 30 40 Kilometers 1400000

2800001400000 300000 320000 340000 360000 380000 400000 420000 440000 460000 7

2.1.1­ Al Wazeyah District:

The chemical analysis of the ten water samples collected from Al Wazeyah district is given in table 1(Appendix 2). The maximum, minimum and average of fluoride concentration are 1.5, 0.3 and 0.64 mg/l respectively which are illustrated in the given histogram (Fig.2).

Fig.2: Fluoride concentration in selected drinking water from Al Wazeyah District

2.1.2­ Mwoza District: The chemical analysis of the two water samples collected from Mowza district is given in table 2(Appendix 2). The maximum, minimum and average of fluoride concentration are 0.51, 0.2 and 0.36 mg/l respectively which are illustrated in the given histogram (Fig.3).

Fig.3: Fluoride concentration in selected drinking water from Mwoza District

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2.1.3­ Maqbanah District: The chemical analysis of the 14 water samples collected from Maqbanah district is given in table 3(Appendix 2). The maximum, minimum and average of fluoride concentration are 1.5, 0.18 and 0.78 mg/l respectively which are illustrated in the given histogram (Fig.4).

Fig.4: Fluoride concentration in selected drinking water from Maqbanah District

2.1.4­ Mawyah District: The chemical analysis of the 19 water samples collected from Mawyah district is given in table 4 (Appendix 2). The maximum, minimum and average of fluoride concentration are 1.7, 0.13 and 1.12 mg/l respectively which are illustrated in the given histogram (Fig.5).

Fig.5: Fluoride concentration in selected drinking water from Mawyah District

2.1.5­ Sharab As Salam District:

The chemical analysis of the 11 water samples collected from Sharab As Salam district is given in table 5 (Appendix 2). The maximum, minimum and average of

9 fluoride concentration are 1.33, 0.32 and 0.78 mg/l respectively which are illustrated in the given histogram (Fig.6).

Fig.6: Fluoride concentration in selected drinking water from Sharab As Salam District

2.1.6­ Sharab Ar Rownah District: The chemical analysis of the five water samples collected from Sharab Ar Rownah district is given in table 6 (Appendix 2). The maximum, minimum and average of fluoride concentration are 0.69, 0.25 and 0.49 mg/l respectively which are illustrated in the given histogram (Fig.7).

Fig.7: Fluoride concentration in selected drinking water from Sharab Ar Rownah District

2.1.7­ Dimnat Khadeer District: The chemical analysis of the 7 water samples collected from Dimnat Khadeer district is given in table 7 (Appendix 2). The maximum, minimum and average of fluoride concentration are 1.5, 0.04 and 0.88 mg/l respectively which are illustrated in the given histogram (Fig.8).

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Fig.8: Fluoride concentration in selected drinking water from Dimnat Khadeer District

2.1.8­ Hayfan District: The chemical analysis of the four water samples collected from Hayfan district is given in table 8 (Appendix 2). The maximum, minimum and average of fluoride concentration are 1.5, 1 and 1.2 mg/l respectively which are illustrated in the given histogram (Fig.9).

Fig.9: Fluoride concentration in selected drinking water from Hayfan District

2.1.9­ Jabal Habashi District: The chemical analysis of the seven water samples collected from Jabal Habashi district is given in table 9 (Appendix 2). The maximum, minimum and average of fluoride concentration are 1.5, 0.2 and 0.73 mg/l respectively which are illustrated in the given histogram (Fig.10).

Fig.10: Fluoride concentration in selected drinking water from Jabal Habashi District

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2.1.10­ Al Mawasit District: The chemical analysis of the 14 water samples collected from Al Mawasit district is given in table 10 (Appendix 2). The maximum, minimum and average of fluoride concentration are 1.5, 0.4 and 0.8 mg/l respectively which are illustrated in the given histogram (Fig.11).

Fig.11: Fluoride concentration in selected drinking water from Al Mawasit District

2.1.11­ Al Mukha District: The chemical analysis of the 5 water samples collected from Al Mukha district is given in table 11 (Appendix 2). The maximum, minimum and average of fluoride concentration are 1, 0.72 and 0.86 mg/l respectively which are illustrated in the given histogram (Fig.12).

Fig.12: Fluoride concentration in selected drinking water from Al Mukha District

2.1.12­As Salow District: The chemical analysis of the 8 water samples collected from As Salow district is given in table 12 (Appendix 2). The maximum, minimum and average of fluoride

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concentration are 1.5, 0.15 and 0.75 mg/l respectively which are illustrated in the given histogram (Fig.13).

Fig.13: Fluoride concentration in selected drinking water from As Salow District

2.1.13­Ash Shammayatain District: The chemical analysis of the 29 water samples collected from Ash Shammayatain district is given in table 13 (Appendix 2). The maximum, minimum and average of fluoride concentration are 1.5, 0.06 and 0.81 mg/l respectively which are illustrated in the given histogram (Fig.14).

Fig.14: Fluoride concentration in selected drinking water from Ash Shammayatain District

2.1.14­ At Aaiziyah District: The chemical analysis of the 31 water samples collected from At Aaiziyah district is given in table 14 (Appendix 2). The maximum, minimum and average of fluoride concentration are 10, 1.08 and 3.38 mg/l respectively which are illustrated in the given histogram (Fig.15).

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Fig.15: Fluoride concentration in selected drinking water from At Aaiziyah District

The maximum, minimum and average concentration of fluoride from water samples of all the fourteen districts are grouped and given in Fig.16. It's clearly observed from the given (fig.16), that the At Aaiziyah district has the highest concentration of fluoride ion in the chemistry of water (the most densely populated region in Taiz Governorate). Hence the picture of the fluoride concentration in the water from Taiz governorate became obvious which is limited to some parts of At Aaiziyah district and its surrounding new districts. Generally the fluoride concentration in groundwater could not be controlled by the district limits, but geology, drainage basin and topography of the area are the most important factors can play a vital role in this concern.

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Fig.16: Fluoride concentration in selected drinking water from Taiz Districts

2.2 Delineation of fluoride contamination areas:

The collected chemical analyses of the wells and springs from the selected areas were used for drawing the iso-line contour map of fluoride ion concentration. The areas of high fluoride concentration more than 1.5 mg/l marked as fluoride contaminated area (bold green color), as it's shown in Figure 17.

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Fig.17: Iso-line contour map of fluoride ion concentration from At Aaiziyah District and its surrounding villages

Elev. (amsl) Water Sample Location 2900

2700 Alburayhi 1.5 F conce. mg/l 2500 1510000 2300

Al Howban 2100

Hidhran 1900 Y 1700

1500 1500000 Taiz City 1300

1100

Jabal Sabir 900 700 380000 390000 400000 410000 X

16 0510 Km

It's clearly observed that, the villages of Jabal Sabir, Hawban, Hethran and Al- Bryehey as well as Taiz City, are the most affected areas by fluoride contamination in groundwater.

2.3 Topography of the affected area: Physiography and geology are the principal factors having controlled the formation and distribution of groundwater. Physiography of any area is characterized by its topography, morphology, and climate. The cross relationship of these elements together with geology, all determine hydrogeological characteristics The fluoride concentration area lies in the Taiz plain, where its upper part occupies the area between high mountains of Dhisufall to the north, J.Sabir to the south and middle mountain ridge to the west and bounding by loess sediments plateau to the east. The topography of the Taiz plain varies from level plain to steep slopes and hills composed principally of restricted volcanic rocks; the sands and outwash sediments covered the basin of the wadis. Taiz plain ranges in elevation between 1000 m to 1300 m, it receives about 500 mm/yr of rainfall and significant recharge form runoff of surrounding mountains (A. Abdulaziz, 2005).

2.4 Climate: The climatic conditions in the area are controlled essentially by topographic elevations. It can be described as arid in the areas below 1000 m (a.m.s.l) and semi arid in the areas above 1000 m (a.m.s.l). The average maximum temperature ranges between 25°C in December and 41ºC in June. The mean monthly relative humidity is ranging between 47 % in November and 73 % in February. The average annual rainfall is about 540 mm/yr and the average annual potential evapotranspiration is about 2033 mm/yr (A. Abdulaziz 2005).

For detail evaluation of the vertical and horizontal distribution of fluoride concentration, the affected area divided into three main locations according to its

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geology and physiography, they are 1- Al Howban Basin 2) Hidhran & Al Burayhi basin and 3) Jabal Sabir Area:

3. Fluoride Contamination in Groundwater of Al Howban Basin:

Wadi Al Howban is a tributary of the upper Wadi Rasyan basin, located east of Taiz city and covers a total geographic area of about 67 Km2. The mean stream of the basin, has its origin in the hilly regions at an altitude ranges from 1600 to 1800 m above mean sea level. The basin streams flows from north-east to low-lying alluvial plains in the downstream part of Taiz City.

3.1 Geology of Al Howban Basin: Geology plays an important and fundamental role in determining availability of the groundwater. Geochemistry of the rocks through which the water flow, play an important role in determining the concentrations of naturally occurring substances that are dissolved in the groundwater. Most of the area of Taiz Governorates covers by Tertiary volcanics. According to Kruck et al.,(1996), the vcolcanic rocks observed in the Taiz region begin with a lower basic facies (Tb1) followed by an acidic facies (Tr1) then middle basic volcanics (Tb2) erupted as second basic facies followed by (Tr2) as a second acidic facies. The upper basic facies (Tb3) followed by the upper acidic facies (Tr3). These associated with the rhyolitic dyke-in-dyke assemblages (Tdy) and the granite plutons of J.Sabir and J.Habashi were intruded in the late Miocene. A grate part of Al Howban basin covered by Middle basic Volcanics (Tb2) (Fig.18) the Middle basic Volcanics (Tb2) consist of fine grained flood basalt layers intercalated with grey ash having thickness the range of tenths of meters. It partly overlies the (Tr1) or cut as dykes through the older rocks. Middle Acidic Volcanics (Tr2) exposed as isolated patches in the south and north of Al Howban basin. The Middle Acidic Volcanics (Tr2) consists of red coloured ignimbrite intercalated with black obsidian and some layers of green ash with total thickness of about 500 m.

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Quaternary deposits (QW) consist of sands and gravels of various grain sizes, the coarse grained alluvium occur in wadi beds at the foot of the hills, the sands, silt and clay material occur in the wide wadis in the study area. These deposits are derived from the surrounding volcanic rocks the thickness in the upstream of wadis does not exceed 10 m and may reach 60 m in the down streams of the wadis (A. Abdulaziz 2005).

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Fig.18: Geological Map of Al Howban Basin

394000 396000 398000 400000 402000 404000 406000 1508000

Al Arakim

1508000 N Shik Al Bitah Khadim Al Sadarah 1506000 Al Afeef d uhu Al R

1506000 Jabal Wail Mulayh Al Naqqash Al Haddath Al Harrir

Al Tahown 1504000 Batra Al Jub Ja bal Al Maslaqah Damalah Al Howban Al Ritanah Road 1504000 Fault

Al Najdayn Al Sayrah Akamat Mashar Taiz city 1502000 Al Dimnah Ja bal Ali Tr2 miocene upper acidic volcanics Al Lijm Al Judhaymah Al Ursum Tp2 Oligocene / Miocene Jabal Suwaid Jabal Al Middle basic Volcanics

1502000 Taiz City Rudhajah Damh QW Quaternary deposite 1500000 0123Kilometers 1500000

394000 396000 398000 400000 402000 404000 406000

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The geological map of the area (Fig.18) shows that the major faults are oriented N-S to NNW, NW, NE and E-W. Most of them are high angle normal faults with downthrown to the west.

3.2 Recharge and Groundwater Conditions: Recharge means addition of water to subsurface storage from various sources. In the study area, the major source of recharge is the two rainy season precipitation. The first rainy season during April to June with maximum rain fall intensity in May, the second during August to October with maximum intensity in September. The high elevated area (ranges from 1400 to 1800 m above main sea level) of Al Howban basin is the recharge area, which receives the highest value of rainfall during the two rainy seasons. DEY & SOAS (1997) estimates the surface runoff of Al- Howban basin to be 7.9 M m3/year. A contribution part of runoff will be penetrating to the aquifer storage in the form of other recharge type from the study area. Natural groundwater recharge was estimated by NWRA based on the empirical rainfall –runoff ratio which was applied to estimate a percentage of an average annual rainfall contributing to recharge (Nagib Al-Sagir, 1998; TN-98-07). Summery of NWRA's recharge estimates of Al Howban basin is presented in Table No.15. Al Howban basin characterized by two types of aquifers: 1) Alluvial aquifers and 2) Volcanic aquifers.

Table No.15: Summery of NWRA's recharge estimates of Al Howban basin

% of rainfall Recharge M contributes to Outcrop Average m3/year Geological Recharge Zone area, Rainfall, Formation Lower Upper Km2 mm Lower Upper estimate, estimate, est. est. % % QA 41.6 4 5 0.88 1.11 Al Tr2 11.89 531.3 3 4 0.19 0.25 Howban Tb2 75.95 3 4 1.21 1.61 Total 129.24 2.28 2.97 QA= Quaternary deposits; Tr2= Tertiary upper acidic volcanics; Tb2 = Tertiary middle basic volcanics

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3.3 Hydrochemistry of water: The results of the chemical analysis data of groundwaters collected from NWRA for Al- Howban basin are presented in Table No.16. The pH of groundwater varied from 7.0 to 8.60 with a mean of 7.51, indicating alkaline groundwater in nature. Concentration of TDS, a measure of quality, ranged from 498 to 3110 mg/l with a mean of 1874 mg/l. According to the TDS classification, 79 % of the samples of groundwater belonged to the brackish type (TDS> 1000 mg/l). Among the cations, the concentrations of Ca, Mg and Na ions ranged from 6 to 260, 6 to 235 and 85 to 966 mg/l with a mean of 108, 98 and 364 mg/l, respectively. The major ion chemistry data revealed that Na and Ca are the most predominant cationic constituents followed by

Mg. The dissolved anions of SO4, Cl, HCO3 and NO3 ions ranged from 62 to 384, 43 to 1136, 275 to 1403 and 4 to 68 mg/l with a mean of 181, 489, 679 and 35 mg/l respectively. For the major anions (SO4, Cl, HCO3, and NO3), the bicarbonate and chloride are found to be the most predominant anions followed by sulphate and nitrate.

The data of cations and anions were plotted by using AquaChem software version 3.6.4. The piper’s Trilinear diagram showing chemical relationship of groundwater constituents from Al Howban basin is given in Fig.19 from which it can be seen that the dominant cations are sodium and calcium, while the bicarbonate and chloride are the dominant anions. The dominant hydrogeochemical facies were identified scattered in the, Na + Ca, Mg cation subfacies, and HCO3 + Cl, SO4 anion subfacies. The high Na in the groundwater may be related to the cation exchange operative in the aquifers (Guo et al. 2006).

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p

80 80 60 60 40 A A 40 AAA 20 A A 20 AA MgAAAAAA SO4 AAAA A AAAA A 80A 80 AA 60 A 60 A 40 40 A AAAAAAA A 20 AAAAAAAA AAA A 20 A AAAA AA AAAAAAAAA A A AA AAAA AAAA 80 60 40 2 0 0 0 0 0 2 4 6 8 Ca Na+K HCO3 Cl

Fig.19: Piper's Diagram of water samples from Al Howban Basin

3.4 Geochemical modeling: The chemistry of groundwater is the result of interaction between rain and the rock near the earth's surface. In order to study the chemical equilibrium existing in groundwater and identify the source of high fluoride concentration in groundwater from the study area, the concept of speciation modeling has been used. The most important results of speciation calculations are saturation indices (SI) for minerals, which indicate whether a mineral should dissolve or precipitate. The solubility limits for fluorite and calcite provide a natural control on water composition in a view that calcium, fluoride and carbonate activities are

interdependent (Kundu et al. 2001). The saturation indices (SI) of fluorite (CaF2) and

calcite (CaCO3) in the groundwater samples were calculated using PHREEQC Interactive, a computer programme of U.S. Geological Survey, version 2.8 (2003) (Table No.17) and are plotted in Fig.20, which shows that all of the samples are oversaturated with respect to calcite except one sample whereas, all of samples have been found undersaturated with respect to fluorite. This situation of solubility control on the higher concentration of fluoride can be explained by the fact that fluoride ions

in groundwater can be increased as a result of precipitation of CaCO3 at high pH, which removes Ca2+ from solution allowing more fluorite to dissolve. These released 2+ 2- Ca ions combine with CO3 ions to further enhance the precipitation of CaCO3. Therefore, fluorite udersaturation in groundwater of area under study might be due to

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the calcite saturation, preventing it by reducing calcium activity and allowing more fluorite to dissolve thereby increasing the F/ Ca ratio of solution. Hence calcite and fluorite are the main minerals controlling the aqueous geochemistry of elevated fluoride ion contamination occurring in the groundwater of Al-Howban Basin.

Fig.20: Plot of calcite saturation index versus fluorite saturation index

3.5 Special Variation in the Fluoride Concentration: The special variation in the fluoride ion concentration in the groundwater from Al Howban basin was evaluated. From the data presented in table no.16, it's observed that, the maximum, minimum and average F- concentrations are 3.6, 0.98 and 1.65 respectively. The special variation contour map in F- from water samples of the study area is given in Fig.21. Tow low concentration zones of F- less than 1.5 mg/l have been observed in the upstream part of the basin around Al Haddath and Al Afeef villages, and another one zone restricted to the downstream part of the basin extends from Jabal Al Damalah to Rudhajah villages. However, most of the basin area covered by F- concentration ranges from 1.5 to 3 mg/l. The values of F- exceeds 3 mg/l have been restricted to the middle part of the basin extends from Al Howban to Bitah villages in north to Al Dimnah in the south. In order to understand the vertical distribution of the fluoride ion concentration from the water of the study area, the type of the sample water (Dug, Bore and Spring)

24

evaluated separately. The following histogram represents the maximum, minimum and average of F- concentration for each well type form Al Howban basin.

.

Fig.22: Variations of F- concentrations of Springs, Dug and Bore wells from Al Howban Basin

The high average F- concentration value observed in the dug well samples followed by springs and bore wells. It can be concluded that, the shallow aquifers reflects higher fluoride contamination than the deeper aquifers.

3.6 Drinking Water Sources: The water to be used for drinking purposes must meet very high standards of physical, chemical and biological purity. It should be appetizing, clear, transparent with constant temperature and free from undesirable physical properties like cloudiness, objectionable odour and taste. Certain minimum quality parameters for this requirement have been suggested by World Health Organisation (WHO, 1971). All the 33 samples analyzed from Al Howban area are used for drinking and domestic uses except samples no. 3,4,5,6,9,15,19,20,25 and 26 (Table No.16). The minimum and maximum values of groundwater samples from Al Howban area have also been given. It is evident from these values that major ions are far beyond the permissible limits for majority of the samples. Out of 23 groundwater samples (using for drinking purposes), 13 samples have shown F- concentration values above the maximum permissible limit of 1.5 mg/l. Obviously,

25

57% of the water used for drinking purposes is contaminated by fluoride ion concentration in Al Howban Basin.

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Fig.21: Contour map of fluoride ion distribution in groundwater of Al Howban Basin

394000 396000 398000 400000 402000 404000 406000

N #S 1508000 #· Al Arkim #S 550 Shib Al S# 1508000 Al Q urf Kha di m 10 11#S #S S# #S Al S adrah Bita h 7 S# 9 # #S 25 S

Al Afi f 1506000 S# d 19 uhu 5 Al R S# 4 6 S# #S 1506000 S# #S S# Al Naqqash Jabal 18 Mulayh Wa il S# 3 Quran #S S# ah Shabanyah Legend 15 Al Bat ra #S S# Al Taa ow n Al Haddath #S 21 1 #S W.Point Sample Al Harrir S# 32 1504000 23 20 S# S# #S Village S# S# #S Maslikah Catchment 13 14 Al Haw ban n 2 Al J UB S#S# # ba 1504000 #S S#·S# aw S# Boundary l H 31 Jabal Al i A 8 S# Asphalt Road Da malah ad 26 S# #S W S# 30# Aka mat Al Ri tanah S Mashar Wadies 33 27 # 17# S# S S Al Di mnah Jabal Ali Taiz City 16 #S #S 28 #S S# Al Najdayn Al S ayrah Central S# 1502000 Al Ursum F Values Security Al Judhaymah 29 S##S Al Lijm #S ( mg/l) 1 #S . 24 Al Q ura yn 1 6 . S# 1502000 12 4 Jabal S# 22 < 1.5 Suwaid S# Rudhaja#S 1.5 - 3 > 3 < 1500000 1500000 394000 396000 398000 400000 402000 404000 406000 1000 0 1000 2000 3000 Kilometers 27

4. Fluoride Contamination in Groundwater of Hidhran & Alburayhi Basin: Hidhran & Alburayhi Basin located north west Taiz city within the lower part of apper Wadi Rasyan, where the downstream sectors of of all other subcatchments converge. Morphologically, Hidhran & Alburayhi Basin is a flat or slightly undulating terrain located at altitude from 1400 to 800 m. Average rainfall is the lowest of the whole upper Wadi Rasyan and likely dose not exceed 400 mm/year (NWRA 1999).

4.1 Geology of Hidhran & Alburayhi Basin: The geological map of Hidhran & Alburayhi Basin is given in Fig.23. it can be seen from the geological map that, the older stratigraphic unit exposed in the area is the lower basalt volcaniclastics (Tb1) which composed of greenish, fine-grained flood basalts and consist of horizons of compact fine grained basaltic volcanics (Alkali basalt, basanite, olivne nephelinite) interbeded with grey ash and some rhyolithic layers. A boulder layer containing well rounded basalt and limestone boulders is intercalated in the sequence. Tb1 exposed as isolated patches north of study area. The lower acidic volcanics (Tr1), or so-called the ryholite plateau is composed of rhyolites, ignimbrite and obsidian intercalating with tuff and breccia. It is yellow, gray, green and pink in color, flow-banded; holocrystalline rhyolite stocks with columnar forms. The major outcrops of this unit occur in the north and east borders of the study area. The middle acidic volcanics (Tr2) are the most predominant volcanic units in the study area. This unit consists of fine grained flood basalt layers intercalated with grey ash having thickness in the range of tenths of meters. It partly overlies the (Tr1) or cut as dykes through the older rocks. The middle acidic volcanics (Tr2) exposed in the south of study area surrounding Taiz city. This sequence consists of red coloured ignimbrite intercalated with black obsidian and some layers of green ash with total thickness of about 500 m. It has only limited distribution, exposed as small separated hills surrounding Taiz city and adjacent to the northern and southern slopes of J.Sabir. The upper basic volcanics (Tb3) outcrops as small hills in Al Hawban area to the south of Taiz Sana road followed by the last rhyolitic eruptions of whit or pinkish ignimbrite. The volcanic activity in the late Tertiary (Miocene to

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Pliocene Time) led to the eruptions of the upper basic volcanics (Tb3) which composed of compact basaltic lava flows intercalated with red and white ash layer. Quaternary deposits (QW) consist of sands and gravels of various grain size, the coarse grained alluvium occur in wadi beds at the foot of the hills, the sands, silt and clay material occur in the wide wadis in the study area. These deposits are derived from the surrounding volcanic rocks the thickness in the upstream of wadis does not exceed 10 m and may reach 60 m in the down streams of the wadis.

4.2 Groundwater Conditions and Recharge Area: Hidhran & Alburayhi Basin carachtrised by two types of aquifers: 1- Qaternary deposits aquifer: Consists of alluvoium of different grain sizes which ranges from silt to boulders and forms potential aquifer in the valley floor areas. The total thickness of this aquifer ranges from 10 to 35 m and depth to water table ranges from 5 to 30 m (NWRA 2009). The hydraulic conductivity and transmissivity of this aquifer ranges from 199 to 0.3 m/d and 596 to 9 m2/d respectively. According to NWRA/Taiz report (2009), this aquifer conceder to be poluted and not suitable for human consumption. 2- Fractured Volcanics Aquifer: it consists of tertiary volcanics, where the weathering of basaltic flows has helped in development of weathered basaltic aquifers in the study area. According to NWRA (2009) study, the depth to watre table ranges from 50 to 300 meter, the yeld of this aquifer about 5 l/s and transmissivity 7.2 m2/d.

As its mentioned, Hidhran & Alburayhi Basin receives an average rainfall of about 400 mm/year. Direct groundwater recharge was estimated by NWRA (2009) based on the empirical rainfall in Hidhran & Alburayhi Basin to be about 3.5 M m3/year. An empirical approch was applied by V. Rebakov (2004), to estimate the indrect recharge from floods and baseflow in the main wadies of Al Malih and Al Milihah to be around 1.1 M m3/year.

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Fig.23: Geological map of Hidhran &Al Burayhi Basin

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4.3 Hydrochemistry of water: The chemical analyses collected from NWRA/Taiz on Hidhran & Alburayhi Basin were used to evaluate the geochemical process controlling the chemistry of groundwater from the study area. The results of the chemical analysis data of groundwaters collected for Hidhran & Alburayhi Basin are presented in Table No.18. The pH of groundwater varied from 6.94 to 8.12 with a mean of 7.43, indicating alkaline groundwater in nature. Concentration of TDS, a measure of quality, ranged from 1023 to 5683 mg/l with a mean of 2872 mg/l. According to the TDS classification, all the samples of groundwater belonged to the brackish type (TDS> 1000 mg/l). Among the cations, the concentrations of Ca, Mg and Na ions ranged from 40 to 450, 18 to 360 and 131 to 1254 mg/l with a mean of 179, 154 and 524 mg/l, respectively. The major ion chemistry data revealed that Na and Ca are the most

predominant cationic constituents followed by Mg. The dissolved anions of SO4, Cl,

HCO3 and NO3 ions ranged from 96 to 480, 160 to 2034, 414 to 1525 and 0 to 33 mg/l with a mean of 236, 881, 913 and 10 mg/l respectively. For the major anions

(SO4, Cl, HCO3, and NO3), the bicarbonate and chloride are found to be the most predominant anions followed by sulphate and nitrate.

The data of cations and anions were plotted by using AquaChem software version 3.6.4. The piper’s Trilinear diagram showing chemical relationship of groundwater constituents from Hidhran & Alburayhi Basin is given in Fig.24 from which it can be seen that the dominant cations are sodium and calcium, while the bicarbonate and chloride are the dominant anions. The dominant hydrogeochemical facies were identified scattered in the, Na + Ca, Mg cation subfacies, and HCO3 + Cl, SO4 anion subfacies. The water samples contain Na+ and HCO3- as the predominant cation and anion, respectively. The high Na+ concentration may be related to the plagioclase which is the main constituent of the basalts and which can release Na+ into groundwater.

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80 80 60 60 40 AA 40 AAAA 20 AA AAA 20 AAAA MgAAAAA A SO4 AAA AAA 80A 80 60 60

40 A AAAAA 40 A AAAAAA 20 A AAAA 20 A AAAAA AAAAAAAAAAA AAA A AAAAAAAAAAAAAA 80 60 40 20 0 0 0 0 2 4 6 8 Ca Na+K HCO3 Cl

Fig.24: Piper's Diagram of water samples from Hidhran & Al Burayhi Basin

4.4 Geochemical modeling: In order to study the chemical equilibrium existing in groundwater and identify the source of high fluoride concentration in groundwater from Hidhran & Al Burayhi Basin, the concept of speciation modeling has been used.

The saturation indices (SI) of fluorite (CaF2) and calcite (CaCO3) in the groundwater samples were calculated and given in Table No.19 and are plotted in fig.25, which shows that all of the samples is oversaturated with respect to calcite whereas, majority of samples have been found undersaturated with respect to fluorite. This situation of solubility control on the higher concentration of fluoride can be explained by the fact that fluoride ions in groundwater can be increased as a result of precipitation of 2+ CaCO3 at high pH, which removes Ca from solution allowing more fluorite to dissolve. These released Ca2+ ions combine with CO32- ions to further enhance the

precipitation of CaCO3. Therefore, fluorite udersaturation in groundwater of area under study might be due to the calcite saturation, preventing it by reducing calcium activity and allowing more fluorite to dissolve thereby increasing the F/ Ca ratio of solution. Hence calcite and fluorite are the main minerals controlling the aqueous

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geochemistry of elevated fluoride ion contamination occurring in the groundwater of Hidhran & Alburayhi Basin also.

Fig.25: Plot of calcite saturation index versus fluorite saturation index from Hidhran & Al Burayhi Basin samples

4.5 Special Variation in the Fluoride Concentration:

The special variation in the fluoride ion concentration in the groundwater from Hidhran & Alburayhi Basin was evaluated. The special variation contour map in F- from water samples of the study area is given in Fig.26. Generally, the most of the water samples showed enhanced concentrations with general increase trends to the northwest and central of Hidhran & Alburayhi Basin areas. The largest concentrations cover most of basin area, with concentrations of greater than 3 mg/l. All the groundwater samples collected from Al Adhmur and Al Mirfid villages were found severely contaminated by the presence of fluoride ion. However, the situation is more aggravated around the Ghurab Al Asfaal locality (Fig. 26). In the Hidhran & Alburayhi Basin, the average F- concentration was figured out to be 3.4 mg/l within the wide range of 1.08 – 10 mg/l minimum and maximum (Table No. 18). Based on WHO recommended guidelines for fluoride in drinking water, 83.9 % (n = 26) out of total 31 groundwater samples were above the optimum level of 1.5

33

mg/l. The population living in these areas is very dense and thus susceptible to higher dental and chronic skeletal fluorosis. Highest concentrations were found to be 10 mg/l from Ghurab Al Asfaal, 5.8 mg/l from Al Adhmur village and 5.4 mg/l in groundwater samples collected from Al Gail village. For convenience in description, groundwater samples have been grouped into three categories according to their concentration of F- and associated risk to human population (Fig. 5). A total of 16.13% (n = 5) groundwater samples were found to be within prescribed WHO limits (0.0–1.5 mg/l), whereas, 35.48% (n = 11) within 1.5– 3.0 mg/l and 48.39 % (n = 15) above 3.00 mg/l (Table 1). In order to understand the vertical distribution of the fluoride ion concentration if any, the type of the sample water (Dug, Bore) evaluated separately. The following histogram represents the maximum, minimum and average of F- concentration for each well type form Hidhran & Alburayhi Basin (Fig.27). The high average F- concentration values observed in the dug wells higher than the bore wells from the study area. It can be concluded that, the shallow aquifers reflects higher fluoride contamination than the deeper aquifers.

Fig.27: Variations of F- concentrations of Dug and Bore wells from Hidhran & Al Burayhi Basin

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Fig.26: Contour map of fluoride ion distribution in groundwater of Hidhran Al Burayhi Basin

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4.6 Drinking Water Sources: All the 31 samples analyzed from Hidhran Al Burayhi Basin are used for drinking and the other domestic uses except samples no., A-05, A-06, B-107, B-016, B-26, B-27, B-040 and A-8 (Table No.18). The minimum and maximum values of groundwater samples from Hidhran Al Burayhi Basin have also been given. It is evident from these values that major ions are far beyond the permissible limits for majority of the samples. Out of 23 groundwater samples (using for drinking purposes), 20 samples have shown F- concentration values above the maximum permissible limit of 1.5 mg/l. It can be concluded that 87% of the water used for drinking purposes is contaminated by fluoride ion concentration in Hidhran Al Burayhi Basin.

5. Fluoride Contamination in Groundwater of Jabal Sabir Area: During the field survey of this mission, it has been observed that must of children in Jabal Sabir area are suffering from dental fluorosis. However, there is no information about the chemistry of the springs from Jabal Sabir area was available in NWRA and GARWP. Therefore, it felt necessary to carry out chemical analysis for the springs which is used for drinking purposes to give a clear picture about fluoride concentration in this area. A total of 10 representative spring samples were collected from the north and northeast sides of Jabal Sabir. Water samples were collected in plastic containers of one-liter capacity for detail chemical analysis. The samples were collected and stored below 4°C and analyzed in the Central Research Laboratory of faculty of science in Taiz University. Temperature, pH, and conductivity were measured at the sampling sites. Fluoride color match method by using Waqtech fluoride test was used to analysis fluoride concentration in the field (Photo No.10 Appendix 3). Exact sampling locations were marked with the help of GPS and the coordinates were plotted on map.

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5.1 Geology of Jabal Sabir Area: The rocks of Jabal Sabir are composed of alkaline or peralkaline granites with minor quartz syenite (Youssef, et al.,1992), light grey to pink, medium to coarse-grained, with more porphyritic facies at their borders (Capaldi, et al.,1987) (Fig.28). They appear to have been derived by crystal fractionation from alkaline-transitional magmas analogous to those of the plateau basalts. The granites were formed at shallow depths and intruded the volcanic series (Huchon, et al., 1991). The upper part of Jabal Sabir consists of sequence of red coloured ignimbrite intercalated with black obsidian and some layers of green ash includes rhyolites, felsites, andesites, trachytes, basalts, as well as tuffs. The Jabal Sabir granites are bounded by several faults and the following trends of fractures are arranged in decreasing order of abundance; E-W, NE-SW, N-S and NW- SE. The E-W fault system represents the most important faults controlling the geology of the area. The northern abrupt end of Sabir granites against the Tertiary volcanics is a structural contact along the E-W North Sabir fault. Only from this side, the fine-grained border zone is completely absent, and highly jointed and brecciated core phase is exposed (Youssef et al., 1992).

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Fig.28: Geological Map Jabal Sabir Area

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5.2 Recharge and Groundwater Conditions: Jabal Sabir is one of the Miocene plutons that from a prominent landmark overlooking the City of Taiz and reaches the highest elevation of 3015 m. The high elevated areas of Jabal Sabir receive high amounts of rainfall during the rainy seasons. Data of rainfall collected from NWRA/Taiz from Miqab rain station indicates that the area receives the maximum rainfall during April to May and August to September. The average annual rainfall ranges from 500 to 1000 mm. The physiography of Jabal Sabir consisting of highly elevated hills with steep slopes (Fig.31). The man-made terraces coves the steep mountainous slopes effectively protect soil from erosion and reducing runoff (Photo No.9, Appendix 3). These techniques have been the main task of the Yemeni farmer for many centuries. These techniques are water harvesting and spate diversion. Due to that, the recharges from direct precipitations in the high elevated and fractured areas as well as recharge from man-mad terraces are the main natural recharge techniques occurred in the study area. The groundwater is controlling by the major faults and fractures of Jabal Sabir granite, for limited area and natural springs all represent the main surface hydrologic features in the study area.

5.3 Hydrochemistry of water: The results of the chemical analysis data of surface samples collected from the Jabal Sabir springs are presented in Table No.20. The pH of water varied from 7.0 to 7.9 with a mean of 7.47, indicating slightly alkaline water in nature. Concentration of TDS, a measure of quality, ranged from 217 to 653 mg/l with a mean of 478 mg/l. According to the TDS classification, all the samples of springs belonged to the fresh type (TDS‹ 1000 mg/l). Among the cations, the concentrations of Ca, Mg, Na and K ions ranged from 25 to 48, 4 to 11, 66 to 178 and 0 to 1.1 mg/l with a mean of 35, 7, 101 and 0.44 mg/l, respectively. The major ion chemistry data revealed that Na is the

most predominant cationic constituents followed by Ca. The dissolved anions of SO4,

Cl, HCO3 and NO3 ions ranged from 8 to 33, 57 to 106, 230 to 380 and 22 to 123 mg/l with a mean of 16, 75, 313 and 59 mg/l respectively. For the major anions (SO4, Cl,

HCO3, and NO3), the bicarbonate is found to be the most predominant anion followed by chloride and nitrate.

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The piper’s Trilinear diagram showing chemical relationship of groundwater constituents from Jabal Sbir springs is given in Fig.29 from which it can be seen that the dominant cations are sodium and calcium, while the bicarbonate and chloride are the dominant anions. The dominant hydrogeochemical facies were identified scattered in the, Na + Ca, cation subfacies, and HCO3 + Cl, anion subfacies. The water samples contain Na+ and HCO3- as the predominant cation and anion, respectively. The high Na+ concentration may be related to the plagioclase which is the main constituent of the granite and which can release Na+ into water.

80 80 60 60

40 40

20 20 Mg SO4

A 80AAAAAAA 80 60 60 40 40

20 20

AAAAAA AAAAAA 8 6 4 2 A 0 0 0 0 0 0 0 0 2 4 6 8 Ca Na+K HCO3 Cl

Fig.29: Piper's Diagram of water samples from Jabil Sabir Area

5.4 Geochemical modeling: In order to study the chemical equilibrium existing in groundwater and identify the source of high fluoride concentration in water from Jabal Sabir area, the concept of speciation modeling has been used.

The saturation indices (SI) of fluorite (CaF2) and calcite (CaCO3) in the spring water samples were calculated and given in Table No.21 and are plotted in (Fig. 29) which shows that all of the samples are undersaturated with respect to fluorite and calcite. This situation of solubility is expected because all the samples located in the recharge area of Sabir Mountain. Therefore, all the fluorite and calcite undergoing the process of disillusion which will add more fluoride and calcium ions to the water. Hence

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calcite and fluorite are the main minerals controlling the aqueous geochemistry of elevated fluoride ion contamination occurring in the spring waters of Jabal Sabir area.

Fig.30: Plot of calcite saturation index versus fluorite saturation index from Jabal Sabir Spring samples

5.5 Special Variation in the Fluoride Concentration:

The special variation in the fluoride ion concentration from the spring water of Jabal Sabir area was evaluated. From the fig.31, it's observed that most of the water samples showed enhanced concentrations with generally increasing trends to the low elevated area while the high elevation shows low concentration of fluoride. The largest concentrations cover most of the foothill area, with concentrations of greater than 2 mg/l. All the water samples collected from the uphill villages were exhibited low fluoride concentration especially the villages located above 2200 m a.m.s.l. (Fig.31). In the Jabal Sabir area, the average F- concentration was figured out to be 1.7 mg/l within the range of 0.52 – 2.3 mg/l (Table 20).

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Fig.31: 3D model of Jabal Sabir topography and Fluoride ion distribution contour map

l s m a

) m ( Fluoride conc. in mg/l in 1.5 000 n 3 io 00 t 28 a 0 v 260 Spring location e l 00 E 24 0 220 0 200 0 180 0 160 0 140 0 120 0 100

0.5

1.5 2

42 0510Km 5.6 Drinking Water Sources:

As stated earlier, the sources of drinking water in Jabal Sabir area are the natural springs exit in the middle and lower part of the mountain. All the 10 spring samples analyzed are used for drinking and the other domestic uses (Table No.20). The minimum and maximum values of groundwater samples from Jabal Sabir area have also been given. It is evident from these values that all the samples of springs belonged to the fresh type. Out of 10 water samples, 7 samples have shown F- concentration values above the maximum permissible limit of 1.5 mg/l. It can be concluded that 70 % of the water used for drinking purposes is contaminated by fluoride ion concentration in Jabal Sabir Area.

6. Types of Fluorosis in the Study Area:

The visual observations in the selected villages identify that the dental fluorosis are the widely fluoride disease observed in the affected areas. The photographs presented in appendix 3 represents some of dental fluorosis from the three selected areas. The dental flourosis ranges from mild to sever fluorosis. High percentage dental fluorosis among the children has been observed in Hidhran Al Burayhi Basin comparatively with the two other areas. Broadly speaking, there is a positive relationship between fluoride in water and the occurrence of dental fluorosis in Taiz region. There seemed to be no skeletal disorders in children due to fluorosis observed in the study area, but no X-ray examinations had been carried out.

6.1 Dietary Practices of the Children: The patterns of dental fluorosis mirror the intake of fluoride during infancy and early childhood. In most places, the fluoride content of drinking water is considered to be sufficient for the characterization of an area with respect to fluoride exposure. There

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have been indications that uptake of fluoride from other sources like food, dust and beverages may be many times higher than that of water (Chowdhury N., et al 1990). During the field survey of this mission, data related to dietary habits of the children affected by fluorosis were collected and presented in table no.22. During the field work of the present study, it's noticed that the percentage of children with fluorosis was very high. Although this can be attributed to the high fluoride in drinking water, the various foods habits (Like drinking black tea and chewing Gat) indicated a high contribution of fluoride to the diet. Some of children, especially from Jabal Sabir area, used to chew Gat daily, and the Gat are cultivated in the man-made terraces of Jabal Sabir alkali granite, where it expected to be the main source of F reach minerals like Fluorite. The use of fluoridated water for cooking increases the fluoride content significantly especially in dry foods like maize flour which absorb much water during cooking. It has been reported that fluoride availability may be influenced by simultaneous intake of food and fluoride-containing compounds in a positive or negative manner depending on the food type, mode of administration and type of fluoride compound (Trautner K and Einwag J 1989). Intake of milk and milk products is said to diminish the fluoride availability by 20- 50% in man. Although the area under study had children taking whole milk (boiled or fermented). From a nutritional point of view, the diet consumed was not balanced and lacked quality. It is composed of maize flour with milk and a few rare vegetables. The photographs of some representatives of dental fluorosis among the children in the affected areas are presented in appendix 3.

Food Type Daily Consumption Weekly consumption Monthly consumption Wheat √ Rice √ Tuna Fish √ Vegetables √ Some of them Chewing Chewing Gat Gat Daily Tea √ Eggs √ Milk √ Maize √

Table No.22: List of the common dietary habits of the children affected by fluorosis

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7. Suggestions for Solutions: Fluoride Poisoning can be prevented or minimized by:

1. Using alternate water sources. 2. By improving the nutritional status of population at risk. 3. By removing excess fluoride (defluoridation).

From the foregoing discussion it's concluded that the suggestions for fluorosis will differ from area to area according to the fluoride concentration in drinking water, physiography and geology of the affected area. Based on that, fluoride poisoning can be prevented or minimized as following: 1- Al Howban and Hidhran & Al Burayhi Basins: The villages located in the south part of Al Howban and the villages extend from Al Burayhi to Hidhran in the Hidhran & Al Burayhi areas are the worst villages affected by fluoride contamination in drinking water, where alternate water sources will be difficult. Therefore, defluoridation of drinking water is the only practicable option to overcome the problem of excessive fluoride in drinking water in these areas.

Extensive research has been done on various methods for removal of fluoride from water and wastewater worldwide. These methods are based on the principle of adsorption, ion-exchange, precipitation–coagulation, membrane separation process, electrolytic defluoridation and electro-dialysis.

The literature survey and the laboratory experiments have indicated that each of the mentioned techniques can remove fluoride under specified conditions. The fluoride removal efficiency varies according to many site-specific chemical, geographical and economic conditions, so actual applications may vary from the generalizations made. Any particular process, which is suitable at a particular region, may not meet the requirements at some other place. It is therefore most important to select an appropriate defluoridation method carefully if a sustainable solution to a fluorosis problem is to be achieved. Following the process selection decision tree given by J.

45

Fawell et al (2006), the effective defluoridation method will be the activated aluminum method (AA).

2- Jabal Sabir area: Due to the high rainfall, rugged topography, low and vertical distribution of fluoride ion concentration in Jabal Sabir Mountain, the suggestion for the problem of fluorosis will be the alternate water source. The harvesting of the high rainfall in the high elevated area of the mountain through the construction of concrete bounds will be very applicable method either as an alternative source or for blending of available drinking water.

8. Conclusions:

The following conclusions were drawn from the present study: 1- The At Aaiziyah district and its surroundings have the highest concentration of fluoride ion in the chemistry of water (the most densely populated region in Taiz Governorate). 2- The villages in Jabal Sabir, Al Howban, Hidhran and Al Burayhi as well as Taiz City, are the most affected areas by fluoride contamination in groundwater resources. 3- In the study area, the major source of recharge is the two rainy season precipitation. The first rainy season during April to June with maximum rain fall intensity in May, the second during August to October with maximum intensity in September. 4- The dominant cations from all the three selected areas are sodium and calcium, while the bicarbonate and chloride are the dominant anions. The dominant hydrogeochemical facies studies concluded that the high Na in the groundwater may be related to the plagioclase which is the main constituent of the basalts and which can release Na+ into groundwater. 5- The geochemical modeling indicates that all of the samples from are oversaturated with respect to calcite (Except samples from Jabal Sabir Area) whereas, all of samples have been found undersaturated with respect to fluorite. This situation of solubility control on the higher concentration of

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fluoride can be explained by the fact that fluoride ions in groundwater can be

increased as a result of precipitation of CaCO3 at high pH, which removes Ca2+ from solution allowing more fluorite to dissolve. 6- The calcite and fluorite are the main minerals controlling the aqueous geochemistry of elevated fluoride ion contamination occurring in the groundwater. 7- It's concluded that, the shallow aquifers reflect higher fluoride contamination than the deeper aquifers from Al Howban and Hidhran & Al Burayhi Basins. 8- Dental fluorosis are the widely fluoride disease observed in the affected areas. 9- There is a positive relationship between fluoride in water and the occurrence of dental fluorosis in Taiz region. 10- Defluoridation method by aluminum method (AA) as a low coat domestic techniques is suggested to be the best solution for removal of excessive fluoride in drinking water from Al Howban and Hidhran & Al Burayhi Basins villages and harvesting of the high rainfall in the high elevated area of the Jabal Sabir mountain area through the construction of concrete bounds to be applicable method either as an alternative source or for blending of available drinking water.

9. Recommendations:

Based on the output of the present study the following are recommended:

1- It's highly recommended to carry out studies about determination of fluoride level in dietary habits of the affected population. 2- Its recommended to curry out studies about skeletal and non-skeletal fluorosis could be exists in the affected population 3- It will be very useful step to start awareness program among the affected population. 4- The causes of the high concentration of fluoride ion in shallow aquifer waters from the study area, needs to be discussed and interpreted through caring out more scientific studies.

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5- Drinking black tea is very common among the children dietary habits. Hence, it's recommended to change this type of habit.

6- Despite the high dental fluorosis prevalence in the area, no restorative treatment is being carried out. Therfore its highley recommneded to provide safe drinking water to fluoride affected areas.

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References: 1. A. Abdulaziz (2005). Geophysical and hydrogeological investigations and groundwater quality evaluation and protection from Upper Wadi Rasyan, Taiz, Yemen. Unpublished PhD Thesis, Egypt. 2. Bell MC, Ludwig TG (1970). The supply of fluoride to man: ingestion from water. Fluoride and human health. WHO monograph series, Geneva: World Health Organization. 3. Capaldi G., S. Chiesa, P. Manetti, G. Orsi et G. Poli, 1987. Tertiary anorogenic granites of the western border of the Yemen Plateau. Lithos, 20, 433-444. 4. Chowdhury NG, Brown RH, Shephered MG. Fluoride intake by infants in New Zealand. Journal of Dental Research 69 (12) 1828-1833 1990. 5. Gaciri SJ, Davies TC (1993). The occurrence and geochemistry of fluoride in some natural waters of Kenya. J of Hydrol 143:395– 412. 6. Gizaw B (1996). The origin of high bicarbonate and fluoride concentrations in waters of the main Ethiopian Rift Valley. J. Afr Earth Sci 22:391–402. 7. Guo et al (2006). Geochemical processes controlling the elevated fluoride concentrations in groundwaters of the Taiyuan Basin, Northern China. J Geochem Explor 93(1):1–12 8. Gupta SK, Deshpande RD, Agarwal M, Raval BR (2005) Origin of high fluoride in groundwater in the North Gujarat-Cambay region, India. Hydrogeol J 13:596–605. 9. Huchon, P., F. Jestin, J.M. Cantagrel, J.M. Gaulier, S. Al Khirbash, et A. Gafaneh, 1991. Extensional deformations in Yemen since Oligocene and the Afar triple junction, Annales Tectonicae, 5 (2), 141-163. 10. J. Fawell, K. Bailey, J. Chilton, E. Dahi, L. Fewtrell and Y. Magara (2006). Fluoride in Drinking-water. IWA Publishing, London UK, 134 P. 11. Jacks G, Bhattacharya P, Chaudhary V, Singh KP (2005). Controls on the genesis of high-fluoride groundwaters in India. Appl Geochem 20:221–228. 12. K.S.Viswanatham (2008). Fluorosis in Yemen-Prevention-Control Status and Strategies for Mitigation. NWRA/Sana'a, Yemen. 13. Kim K, Jeong YG (2005) Factors influencing natural occurrence of fluoride- rich ground waters: a case study in the southeastern part of the Korean Peninsula. Chemosphere 58:1399–1408.

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14. Kundu N, Panigrahi MK, Tripathy S, Munshi S, Powell MA, Hart BR (2001) Geochemical appraisal of fluoride contamination of groundwater in the Nayagarh district of Orrissa India. Environ Geol 41:451–460. 15. Mahramanlioglu M, Kizilcikli I, Bicer IO (2002). Adsorption of fluoride from aqueous solution by acid treated spent bleaching earth. J Fluor Chem 115:41– 47. 16. Nagib M. Al-Sagir, 1998. Estimation of Groundwater Recharge in the Upper Wadi Rasyan. NWRA/PPS Technical Note TN-98-07. 17. Nanyaro JT, Aswathanarayana U, Mungere JS, Lahermo P (1984). A geochemical model for the abnormal fluoride concentrations in waters in parts of northern Tanzania. J Arf Earth Sci 2:129–140. 18. NWRA/Taiz (2006). Technical notice on quality of groundwater in Al- Howban catchment area. 19. NWRA/Taiz (2008). Technical notice on quality of water in Hidhran and Al Burahay basin. 20. Oruc N (2003). Problems of high fluoride waters in Turkey (hydrogeology and health aspects). The short course on medical geology-health and environment. Canberra, Australia. 21. Sorg TJ (1978) Treatment technology to meet the interim primary drinking water regulations for inorganics. J Am Water Works Assoc 70(2):105–111. 22. Subba Rao N, John Devadas D (2003). Fluoride incidence in groundwater in an area of peninsular India. Environ Geol 45:243–251. 23. Susheela A, Kumar AK, Bhatnagar M, Bahadur M (1993). Prevalenceof endemic fluorosis with gastro-intestinal manifestations in people living in some north-Indian villages. Fluoride 26:97–104. 24. Totsche KU, Wilcke W, Korbus M, Kobaza J, Zech W (2000) Evaluation of fluoride-induced metal mobilization in soil columns. J Environ Qual 29:454– 459. 25. Trautner K, Einwag J. Influence of milk and food on fluoride bioavailability

from NaF and Na2FPO3 in man. Journal of Dental Research 68 (1) 72-77 1989. 26. UNICEF (2008), Survey Report about the effect of fluoridation among school children in the district of Sanhan. 27. USGS (2003). A Graphical User Interface to the Geochemical Model PHREEQC. U.S.G.S., Fact Sheet FS-031-02.

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28. Van Der Welle J., 1996. Hydrochemistry and pollution studies in the Upper Wadi Rasyan Catchment. 29. WHO (1971). International standards for drinking water. Geneva. 30. WHO (2006) Guidelines for drinking-water quality. First addendum to third edition, Volume 1, Recommendations. World Health Organization. 31. Youssef, M., H. El-Shatoury and M. Al-Kadasi, 1992. Geology of Gabal Sabir Granitic Mass, Taizz, Yemen Republic. Geology of The Arab World, Cairo University, vol. 1, 433-447.

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Appendix 1

Terms of Reference for Fluorosis study in Selected Villages of

Taiz Governorate by a National consultant

Contamination of water resources mainly groundwater may be anthropogenic or geogenic. Anthropogenic contamination can be checked by the implementation of preventive measures whereas geogenic contamination requires a comprehensive baseline data for making the groundwater management policy UNICEF has made surveys and also conducted a workshop for Fluorosis in Yemen. This study will mainly focus on selected villages of Taiz Basin.

Objectives of the study

To collect baseline data on the Fluoride contamination

To delineate the area of contamination and differentiate the source of(geogenic or anthropogenic) Geological factors like Fluoride bearing rock formations / minerals in the area. / Structural features

To identify the recharge area

To identify vertical and horizontal distribution pattern of Fluoride and other contaminants in water bearing geologic formations and groundwater in the study area

To identify Villages affected by fluorosis

To study mobilization processes of specific contaminants like Fluoride

To develop groundwater conceptual models by using hydro-chemical data

To collect information about reported diseases caused by, fluoride

Collect secondary data on a sample basis the

dietary habits of the children affected by Fluorosis

Outputs

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1. Compilation of hydrogeological Information and preparation of map of fluorosis endemic areas in Taiz; 2. Identify present drinking water sources in the fluorosis affected villages; 3. Compilation of previous chemical data of groundwater ; 4. Groundwater, surface water and rain water sampling chemical analysis With the Field Chemical Kit for Fluoride; 5. Sample survey on dietary practices of the Children in Fluorosis; Endemic areas. And also identify the type of Fluorosis Dental Fluorosis/Skeletal fluorosis by visual observations in selected villages. 6. Suggestions for solutions to the problem of Fluorosis; like Defluoridation and fresh drinking water sources;

7. Starting Date: 15 May 2009

Preparation of interim report and submission after 1 month

ie 15 June 2009

Duration 1 month

Qualifications & Experience: A Masters Degree holder in Geology/Hydrogeology/

The consultant should be a Water Resources Specialist with experience in similar studies of integrated nature particularly in identification of Fluorosis endemic areas and determine the factors responsible for Fluorosis.

Must be Fluent in English and Arabic.

Desirable: a Ph. D Degree with groundwater experience in Yemen

Starting Date: 15 May 2009

Closing Date 15 June 2009

The Consultant would report to the Planning & Studies Head Mr. Mohd Sultan

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Appendix 2 Table No.1: Chemical analysis data of selected drinking water from AlWazeyah District.

Sample C Ph E.C TDS ALK TH Ca Mg Cl NO3 SO4 Fe F No. 1 30 8 2850 1995 150 488 412 76 519 18 470 0.03 1.13 2 32 8 168 1040 250 370 260 110 200 5 290 1.5 0.5 3 37 7.5 2800 1820 280 454 320 134 340 20 450 1 0.5 4 36.8 8 2300 1495 220 520 272 248 300 10 400 2.5 1.5 5 38 7.7 1836 1103 130 300 240 60 120 27 205 0.5 0.3 6 26.3 7.6 1550 900 300 320 210 110 126 15 260 0.1 0.7 7 30 8.5 3600 2340 260 680 520 160 400 10 2875 3.5 0.3 8 38.2 7.8 1150 748 200 300 200 100 150 10 50 1 0.4 9 38 8 1450 943 200 220 150 70 230 16 65 1 0.56 10 30 7.8 2000 1200 150 300 200 100 250 20 200 1 0.5

Table No.2: Chemical analysis data of selected drinking water from Mowza District.

Sample No. C Ph E.C TDS ALK TH Ca Mg Cl NO3 SO4 Fe F 1 35 8.5 1610 1127 200 400 300 100 250 27 300 1 0.51 2 35 9 4400 2860 450 1000 85 150 490 17 640 4.5 0.2

Table No.3: Chemical analysis data of selected drinking water from Maqbanah District.

Sample C Ph E.C TDS ALK TH Ca Mg Cl NO3 SO4 Fe F No. 1 32 7.2 1150 650 160 660 200 460 120 48 300 0.3 1.2 2 32 7.5 1268 744 74 380 240 140 160 15 225 0.03 1.5 3 35 7.8 940 436 150 280 70 110 35 26 40 1 0.5 4 33 7.5 2230 1450 210 525 55 45 350 12.8 315 0.5 0.2 5 33.4 7.7 1528 993 266 580 122 66 70 53 450 0.4 1.2 6 35 7.8 787 512 150 512 70 44 80 31 100 0.3 0.9 7 35 7.4 780 468 140 280 80 40 75 2.5 90 0.3 0.5 8 32 7 1175 764 200 227 105 42 50 20 50 0.3 0.37 9 33.3 7.7 2480 1612 260 434 320 114 320 20 450 1 0.5 10 28 8 2660 1729 200 600 400 200 200 10 200 1 1 11 35 8 2800 1820 300 600 450 150 450 10 300 1 1.5 12 33.8 8 1098 714 150 200 120 80 140 62 68 0.5 0.6 13 35 8 2700 1890 378 580 490 90 31 18 680 0.8 0.7 14 39.4 8 904 588 100 490 290 200 63 18 270 0.3 0.18

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Table No.4: Chemical analysis data of selected drinking water from Mawyah District.

Sample C Ph E.C TDS ALK TH Ca Mg Cl NO3 SO4 Fe F No. 1 30 7.5 960 570 350 310 266 44 200 34 250 0.2 1.2 2 8.5 4200 2940 272 840 720 120 458 213 2000 0.22 0.1 3 26 7.6 1800 910 90 290 200 90 330 12 280 0.1 0.84 4 27 8 3800 2660 280 758 576 182 460 50 368 0.9 0.27 5 32 7.5 1780 1156 300 600 400 200 366 48 500 0.56 1.2 6 30 8 2300 1631 200 360 280 140 160 33 300 0.3 1.7 7 34 8 2000 1300 190 560 416 150 484 10 300 0.5 1 8 30 7.8 1860 1209 190 500 416 150 350 250 9 30 9 3220 2254 170 170 100 700 270 10 300 0.3 1.5 10 39 8 2600 1566 200 460 360 100 350 13 400 0.04 1.5 11 65 8 2300 1495 182 250 190 60 282 18 300 1 1.4 12 31.6 7.2 2330 1515 70 400 108 55 420 21 380 2.73 0.94 13 35.6 8 2230 1515 70 400 108 55 420 20 450 1.88 1.5 14 31 8 1835 1101 150 240 76.8 39.2 330 17 200 0.65 0.13 15 36 9 3540 2478 200 420 270 150 600 10 500 2.5 1.5 16 37 8 3100 2100 161 244 200 44 500 10 400 1.7 1.5 17 33 8 2330 1515 170 483 281 202 150 10 410 0.5 0.9 18 28 8.5 3800 2470 200 850 710 100 200 60 600 2.5 1.2 19 28 8.04 1561 1015 300 523 450 173 70 10 320 1 0.5

Table No.5: Chemical analysis data of selected drinking water from Sharab As Salam District.

Sample C Ph E.C TDS ALK TH Ca Mg Cl NO3 SO4 Fe F No. 1 29 8 1900 910 441 372 250 122 146 24.2 136 0.2 0.32 2 28 7.5 1600 896 177 188 110 78 170 30 240 0.2 0.5 3 27 8.5 1250 875 276 260 160 100 149 18 145 0.9 1.33 4 30 7.8 1400 910 170 260 160 100 100 10 200 0.5 0.5 5 29 8 1014 608 160 280 77 21 140 15.4 60 0.3 1.3 6 33 8.7 1670 1086 199 400 300 100 150 32 150 0.5 0.5 7 28 8.5 685 445 150 250 180 70 100 18 100 0.3 0.4 8 25 8 890 599 150 280 150 130 100 43 150 0.5 1 9 25.5 7.5 1000 650 210 360 270 90 37 15 96 0.7 10 26.8 7.6 1000 600 280 280 170 90 70 15 120 0.8 11 40 8 2000 1200 260 100 40 244 140 14 510 0.3 1.2

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Table No.6: Chemical analysis data of selected drinking water from Sharab Ar Rownah District.

Sample C Ph E.C TDS ALK TH Ca Mg Cl NO3 SO4 Fe F No. 1 28 7 1200 720 250 470 270 200 150 31 250 0.3 0.35 2 28 7 1100 660 220 300 200 100 110 28 200 0.3 0.25 3 34 8 3780 2431 140 1680 560 268 900 7.4 220 0.12 0.64 4 34 8 3200 2240 100 1400 400 110 700 7.4 200 1.5 0.69 5 28 7 780 546 284 336 284 152 106 15 54 0.02 0.5

Table No.7: Chemical analysis data of selected drinking water from Dimnat Khadeer District

Sample No. C Ph E.C TDS ALK TH Ca Mg Cl NO3 SO4 Fe F 1 26.5 8.5 1000 618 292 256 142 140 398 28 175 0.15 0.7 2 26 7 926 601 287 364 102 256 100 22.4 100 0.5 0.04 3 32.4 8 2800 1820 100 360 237 123 250 5 600 1.4 0.5 4 43.4 9 3900 2000 464 1676 776 900 534 15 1200 1 1.01 5 38 7.5 1430 930 156 500 296 204 83 5 370 0.8 1.2 6 32 7.5 1542 925 294 292 168 124 190 15 130 0.04 1.2 7 33 7.5 2330 1398 342 558 432 126 230 15 100 0.04 1.5

Table No.8: Chemical analysis data of selected drinking water from Hayfan District

Sample C Ph E.C TDS ALK TH Ca Mg Cl NO3 SO4 Fe F No. 1 31.5 8.5 3630 2360 120 240 160 80 680 10 700 0.4 1.5 2 26.7 8.5 1600 1040 281 158 149 120 307 14 400 0.3 1 3 7.5 1500 1050 300 460 280 180 320 90 1000 0.42 1 1.3 4 7.2 1099 769 208 390 290 100 156 45 400 0.3 0.7 1

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Table No.9: Chemical analysis data of selected drinking water from Jabal Habashi District

Sample C Ph E.C TDS ALK TH Ca Mg Cl NO3 SO4 Fe F No. 1 34 7.5 707 460 236 398 246 152 59 21 61 0.5 0.3 2 28 8 1800 1260 150 358 226 132 198 10 200 1 0.2 3 40 8.7 2340 1638 35 390 362 28 551 4 1165 0.3 1.3 4 29 8 850 510 200 330 280 50 50 2 260 0.6 0.9 5 30 8 1080 687 180 200 120 80 100 10 70 1 1.5 6 30 7 670 436 160 290 160 80 50 24 50 0.3 7 33.2 8 1060 684 200 290 180 182 70 6 200 0.64 0.2

Table No.10: Chemical analysis data of selected drinking water from Al Mawasit District

Sample No. C Ph E.C TDS ALK TH Ca Mg Cl NO3 SO4 Fe F 1 37 970 460 267 330 217 113 50 17 55 0.7 2 31 8 1000 700 208 290 162 128 162 15 120 0.1 0.8 3 30 7.6 900 630 157 314 180 384 92 15 26 0.07 0.8 4 37 8 1230 861 210 400 300 100 176 26 375 0.71 0.5 5 38 8 1230 861 210 400 300 100 176 26 375 0.7 0.5 6 34 7.8 930 605 372 260 200 60 23.8 17 350 0.12 1.2 7 35 7.6 1030 670 288 400 240 160 80 10 360 0.1 1 8 26.2 8 680 408 280 170 110 50 280 10 60 0.3 0.5 9 27 8 730 638 290 190 92 60 292 10 60 0.3 0.5 10 27 8.5 730 475 360 200 158 42 100 53 75 0.76 1.3 11 30 7 1150 690 290 350 180 170 110 15 250 0.09 0.7 12 28 8 980 637 220 250 180 70 120 20 100 1.5 1.5 13 26 8 900 585 112 270 70 23 70 5 75 0.65 0.81 14 25 7.8 863 561 173 200 150 50 60 53 61 0.9 0.4

Table No.11: Chemical analysis data of selected drinking water from Al Mawasit District

Sample C Ph E.C TDS ALK TH Ca Mg Cl NO3 SO4 Fe F No. 1 35 7.6 2500 1750 2 27 7.6 2300 1380 340 600 420 280 270 33 680 0.2 0.8 3 27 7.5 2000 1200 310 560 400 160 210 30 550 0.9 4 35.4 7 1636 1063 180 570 154 44.4 200 5 200 0.3 1 5 35 8 1136 738 150 300 150 100 150 35 190 1.25 0.72

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Table No.12: Chemical analysis data of selected drinking water from As Salow District

Sample C Ph E.C TDS ALK TH Ca Mg Cl NO3 SO4 Fe F No. 1 28 8 880 572 400 440 360 80 42 21 350 0.5 0.9 2 7.8 735 478 200 220 140 80 70 10 50 0.8 1.5 1.8 3 7.8 945 564 390 178 202 39 370 26 120 0.2 0.7 1 4 7.2 850 510 179 216 158 58 47 1 140 0.23 0.15 0.45 5 9 6000 4200 80 1160 1100 80 1700 10 1650 0.3 0.3 6 7.8 1300 845 280 370 260 110 50 30 400 1.5 1 1.3 7 7.5 1050 684 250 220 140 80 150 42.7 10 1.5 0.3 8 7.2 1226 797 210 416 84 50 70 14 210 1 0.65 0.95

Table No.13: Chemical analysis data of selected drinking water from Ash Shammayatain District

Sample C Ph E.C TDS ALK TH Ca Mg Cl NO3 SO4 Fe F No. 1 32 7.5 740 518 290 316 200 116 80 15 70 0.3 0.7 2 38 7.5 650 455 220 150 130 20 150 19 67 0.37 0.33 3 28 7.6 758 531 268 260 150 110 214 16 80 0.3 0.6 4 24 7.6 800 580 360 370 170 200 160 15 120 0.03 0.7 5 27 8 1170 819 150 350 200 150 156 11 175 0.56 0.16 6 26 8 1300 910 156 312 200 112 165 20 180 0.4 0.2 7 31 7.5 1100 770 262 660 144 510 140 17 80 0.06 0.95 8 30 7.5 1000 700 368 400 200 200 214 25 180 0.04 1 9 32 8.5 1496 972 280 450 270 170 310 30 425 0.3 1.2 10 31 7.5 1100 770 262 660 144 516 140 20 350 0.3 1.5 11 25 8 1420 923 226 208 183 25 180 14 200 0.14 0.6 12 34 8 1436 933 300 274 253 21 200 10 290 0.3 1.5 13 28 8.5 1300 750 206 467 236 231 157 4 205 1.17 1.5 14 40 7.5 1450 943 130 330 200 130 820 10 330 1 0.75 15 40 7.5 880 532 200 250 155 100 55 10 215 1.5 0.5 16 30 7.8 680 409 200 380 180 200 80 10 200 0.8 0.7 17 28 8.5 780 507 200 241 191 50 50 10 40 1.6 0.52 18 23 7.3 1300 845 315 396 52 41 70 21 250 0.1 0.85 19 23 7.2 1600 1040 210 510 88 70 164 6.6 300 0.15 0.51 20 32.4 8 1140 740 160 400 200 200 140 37 400 0.8 0.86 21 41 8 900 585 180 240 160 80 50 12.8 180 0.5 0.5 22 26.8 7.5 847 550 280 250 150 100 100 37 200 0.7 0.87 23 24.7 8.5 4220 2950 399 1400 680 720 400 20 400 1.26 1 24 24.8 8 1180 767 320 480 360 120 200 15 200 1 1.08 25 26.7 8.5 1470 955 250 300 200 100 100 27 100 0.4 0.06 26 26 7.7 1040 458 300 350 200 100 200 10 200 0.8 1.5 27 62 7 1740 1040 200 160 130 30 150 10 870 1 1.2 28 26 8 664 434 250 450 350 100 21 10 150 0.5 1 29 30 7.5 1430 930 240 400 300 100 200 10 300 0.5 0.6

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Table No.14: Chemical analysis data of selected drinking water from At Aaiziyah District

Sample TDS E.C T Na K Ca Mg Cl SO4 HCO3 F No. 1 2701 4220 27 805 7.5 100 24 1030 298 414 2.81 2 2560 4000 28 248 27.5 250 192 621 240 1049.2 3.33 3 1869 2920 28 380 6.7 200 30 444 115 866 1.083 4 1203 1880 28 143 3.28 110 84 266 101 549 1.425 5 5683 8880 28 1254 28 330 204 1953 384 1525 5.05 6 4032 6300 28 407 10 320 348 1456 317 915 2.66 7 3821 5970 28 644 24.02 340 168 1456 96 1005 1.33 8 3891 6080 28 766 19.07 140 240 1154 384 1220 4.008 9 2577 4000 628 5.6 100 90 781 365 610 3 10 1023 1598 29 225 3.3 66 32 159.7 96 549 5.8 11 2406 3760 27 541 7.5 70 125 675 365 641 5.8 12 8020 28 966 45 250 294 2034 480 732 10 13 4922 7690 28 1001 11.7 210 271 1864 394 958 5.45 14 2803 4380 28 465 3.3 70 240 710 216 1159 2.793 15 1235 1930 28 214 0.33 40 96 213 144 610 1.995 16 2451 3830 28 557 4.1 50 138 533 192 1159 2.793 17 3206 5009 28 690 3.28 100 180 886.5 264 1177 3.667 18 3116 4869 28 658 7.5 100 174 887.5 240 1098 3.325 19 1101 1720 28 242 7.5 100 18 177.5 125 579.5 1.729 20 4102 6409 28 791 4.5 240 210 1385 298 1128.5 4.33 21 2106 3291 28 315 8.3 220 96 532.5 144 884.5 3.99 22 1382 2159 28 322 4.2 120 18 302 163 579.5 2.261 23 2336 3650 28 476 10.5 200 66 621 202 884.5 2.66 24 2496 3900 28 455 8.5 130 150 532.5 192 1201.7 2.66 25 1242 1941 28 131 8.03 180 54 266 106 579.5 1.33 26 4339 6780 28 683 5 200 336 1598 355 915 4.921 27 2605 4070 28 161 5.8 360 198 888 120 854 1.672 28 3334 5209 28 435 8.03 450 126 1154 206 915 3 29 4371 6830 28 596 15.13 240 360 1456 326 1220 4.864 30 3443 5380 28 738 6.7 240 114 923 408 1159 3.819 31 1472 2300 28 322 1.68 40 84 249 96 854 1.37

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Table No.16: Chemical analysis of water samples from Al Howban Basin (Source NWRA/Taiz 2006)

Y X Station ID EC Ph TDS Ca Mg Na K Fe Cl SO4 HCO3 NO3 F

1504376 403494 01 1950 7.6 1248 60 40 304 2.5 0.68 231 331 415 12.4 1.5 1503678 404749 02 1301 8.3 833 6 19 253 3.99 0.88 85 154 427 9.99 1.2 1505099 402416 03 4310 7.5 2758 150 150 524 9.61 0.73 888 144 884 29 1.65 1505701 402858 04 4700 7.2 3008 260 168 458 4 0.745 1065 360 512 65 1.5 1505788 403083 05 4860 7.5 3110 224 158 550 10.72 0.685 1072 355 610 58 1.32 1505594 402666 06 2410 7.6 1542 122 71 276 3.895 0.72 309 91 793 32 1.6 1506702 402692 07 2370 7.2 1517 126 68 267 2.5 0.72 366 221 488 52 1.3 1503350 403333 08 2290 8 1466 72 101 248 2.284 0.73 259 202 634 56.8 1.5 1506568 403595 09 3280 7.3 2099 110 90 453 4.06 0.77 586 202 671 66 1.42 1507764 404180 10 2210 7.7 1414 56 80 288 3.94 0.76 284 96 689 47.6 1.8 1507160 404023 11 3110 7.2 1990 80 84 460 4.68 0.745 497 115 872 20 1.95 1501595 395670 12 2660 7.1 1702 200 78 230 4.29 0.745 426 192 622 22 1.2 1503755 394505 13 4860 7.1 3110 228 211 444 10.45 0.785 1136 168 732 64.8 1.44 1503699 396205 14 4000 7.5 2560 100 156 499 9.496 0.745 923 149 610 53 2.25 1504705 396045 15 4620 7.8 2957 50 149 713 11.62 0.785 1136 115 695 23 1.62 1502472 395922 16 2980 7 1907 230 114 200 4.705 0.77 639 115 549 25 1.8 1502819 397394 17 3780 7.2 2419 112 137 472 9.984 0.81 781 110 793 30 2.2 1505303 399385 18 4320 7.4 2765 108 175 518 13.143 0.81 710 365 885 64 1.78 1505865 398710 19 4000 7.4 2560 128 235 317 7.215 0.835 646 365 732 9.821 1.58 1504152 399830 20 2950 7.5 1888 64 114 380 11.134 0.81 415 336 610 32 2 1504315 400386 21 4650 7.7 2876 48 19 966 19 0.88 902 384 732 65.2 1.84 1501409 403811 22 1320 7.8 845 54 47 150 3.94 0.825 71 130 488 31.2 1.6 1504163 398386 23 1988 7.7 1272 102 66 212 3.856 0.855 160 134 732 35 3.6 1501743 398432 24 1507 7.2 965 100 24 179 5.148 0.825 195 62 488 15 1.5 1506346 400599 25 2150 7.1 1376 90 66 260 6 0.828 284 144 580 38 1.6 1503238 400186 26 4420 7.3 2829 200 180 435 11.056 0.81 604 168 1403 42 1.65 1502911 401306 27 3440 7.2 2202 170 108 384 5.65 0.812 426 158 1098 68 1.95 1502413 402017 28 1699 7.3 1087 82 54 191 4.056 0.835 131 86 671 24 1.7 1502009 401427 29 1444 7.5 924 70 50 150 9 0.825 99 163 488 10 1.6 1503164 403732 30 1296 8.3 819 24 19 230 5.85 0.825 85 67 519 8.7 1.8 1503422 405424 31 775 7 495 70 6 85 1.95 0.835 43 72 305 4 1 32 822 8.6 526 20 24 117 4.08 0.862 46 86 275 6 1.05 1502828 396841 33 4350 7.9 2784 54 74 782 8.03 0.928 628 115 1403 25 0.98 Max 4860 8.6 3110 260 235 966 19 0.928 1136 384 1403 68 3.6 60 Min 775 7 495 6 6 85 1.95 0.68 43 62 275 4 0.98

Average 2934.00 7.51 1874.33 108.18 95.00 363.48 6.72 0.79 488.73 180.45 678.94 34.68 1.65 Table No.17: The calculated saturation indices (SI) of fluorite (CaF2) and calcite (CaCO3) in the groundwater samples from Al Howban Basin

Station ID F Sum of Anions Sum of Cations SI (Calcite) SI (Fluorite) mg/l meq/l meq/l 01 1.5 20.45084 19.57288 0.2739 -0.8865 02 1.2 12.79516 12.96983 0.0425 -1.9828 03 1.65 42.99381 42.86708 0.822 -0.5897 04 1.5 46.84335 46.82323 0.4964 -0.4765 05 1.32 48.44352 48.37751 0.8012 -0.6481 06 1.6 24.10247 24.03551 0.8648 -0.5546 07 1.3 23.66059 23.5611 0.264 -0.7258 08 1.5 22.71148 22.74986 0.9153 -0.8753 09 1.42 32.65516 32.70344 0.4067 -0.7687 10 1.8 22.00755 22.00564 0.5791 -0.7819 11 1.95 31.06461 31.03297 0.3018 -0.6061 12 1.2 26.55507 26.51314 0.4556 -0.6211 13 1.44 48.44584 48.32071 0.5008 -0.5956 14 2.25 39.93393 39.77531 0.5027 -0.4837 15 1.62 46.20889 46.06698 0.5435 -1.0774 16 1.8 29.83256 29.67826 0.3556 -0.2495 17 2.2 37.81776 37.64873 0.3781 -0.4298 18 1.78 43.04913 42.65773 0.5563 -0.7014 19 1.58 38.03133 39.69841 0.5582 -0.7582 20 2 29.21843 29.38842 0.3238 -0.722 21 1.84 46.37168 46.46344 0.4254 -0.9144 22 1.6 13.19295 13.18768 0.5628 -0.8094 23 3.6 19.93953 19.84117 0.864 0.0946 24 1.5 15.06096 14.88291 0.248 -0.5675 25 1.6 21.08757 21.38506 0.1178 -0.6634 26 1.65 44.15561 43.99654 0.9224 -0.5078 27 1.95 34.27701 34.21811 0.6909 -0.3371 28 1.7 16.8808 16.94733 0.3707 -0.6047 29 1.6 14.39845 14.3624 0.3689 -0.7107 30 1.8 12.50548 12.9152 0.7452 -1.0107 31 1 7.815394 7.734085 -0.2444 -0.9743 32 1.05 7.728287 8.166529 0.7106 -1.5182 33 0.98 43.47519 43.00454 0.968 -1.4331

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Table No.18: Chemical analysis of water samples from Hidhran & Al Burayhi Basin (Source NWRA/Taiz 2008)

SampleID X Y pH TDS E.C T Na K Ca Mg Cl SO4 NO3 HCO3 F B-98 393166 1504660 7.5 3891 6080 28 766 19.07 140 240 1154 384 5.27 1220 4.008 B-92 392700 1504888 7.1 4371 6830 28 596 15.13 240 360 1456 326 15.128 1220 4.864 B-54 391314 1505502 7.8 3821 5970 28 644 24.02 340 168 1456 96 8.06 1005 1.33 B-41 390731 1505969 7.1 3334 5209 28 435 8.03 450 126 1154 206 8.8 915 3 B-40 383134 1503222 7.3 2605 4070 28 161 5.8 360 198 888 120 6.944 854 1.672 B-33 388626 1502325 7.4 4032 6300 28 407 10 320 348 1456 317 16.12 915 2.66 B-30 386364 1503312 7.4 4339 6780 28 683 5 200 336 1598 355 8.74 915 4.921 B-27 385038 1503944 7.3 5683 8880 28 1254 28 330 204 1953 384 33.11 1525 5.05 B-26 383961 1503951 7.6 1203 1880 28 143 3.28 110 84 266 101 5.33 549 1.425 B-16 384599 1502996 7.3 1242 1941 28 131 8.03 180 54 266 106 8.06 579.5 1.33 B-115 392990 1506693 8.12 1472 2300 28 322 1.68 40 84 249 96 8.06 854 1.37 B-107 393986 1505185 7.6 3443 5380 28 738 6.7 240 114 923 408 6.45 1159 3.819 B-004 383367 1504621 7.3 2496 3900 28 455 8.5 130 150 532.5 192 9.92 1201.7 2.66 A-8 7.3 5213 8020 28 966 45 250 294 2034 480 21.95 732 10 A-74 390750 1503800 7.05 2336 3650 28 476 10.5 200 66 621 202 9.92 884.5 2.66 A-70 392852 1501554 7.1 1869 2920 28 380 6.7 200 30 444 115 3.16 866 1.083 A-65 392934 1503091 7.13 2560 4000 28 248 27.5 250 192 621 240 7.75 1049.2 3.33 A-62 389343 1504746 7.4 1382 2159 28 322 4.2 120 18 302 163 5.02 579.5 2.261 A-61 390903 1504434 6.94 2106 3291 28 315 8.3 220 96 532.5 144 11.22 884.5 3.99 A-6 386444 1505422 7.7 2406 3760 27 541 7.5 70 125 675 365 8.866 641 5.8 A-59 391321 1508115 7.24 4102 6409 28 791 4.5 240 210 1385 298 10.7 1128.5 4.33 A-53 390441 1511441 8 1101 1720 28 242 7.5 100 18 177.5 125 0.56 579.5 1.729 A-52 391497 1511056 7.3 3116 4869 28 658 7.5 100 174 887.5 240 7.75 1098 3.325 A-51 386597 1508155 7.6 3206 5009 28 690 3.28 100 180 886.5 264 6.63 1177 3.667 A-5 385027 1507397 7.4 1023 1598 29 225 3.3 66 32 159.7 96 7 549 5.8 A-46 385960 1509309 8 2451 3830 28 557 4.1 50 138 533 192 9.49 1159 2.793 A-43 387573 1511269 7.9 1235 1930 28 214 0.33 40 96 213 144 12.1 610 1.995 A-42 387848 1509362 7.5 2803 4380 28 465 3.3 70 240 710 216 9.5 1159 2.793 A-39 389032 1508898 7 4922 7690 28 1001 11.7 210 271 1864 394 13.21 958 5.45 A-25 389130 1506557 7.7 2701 4220 27 805 7.5 100 24 1030 298 0 414 2.81 A-008 383572 1507772 7.4 2577 4000 628 5.6 100 90 781 365 13.45 610 3 Max 8.12 5683.00 8880.00 29.00 1254.00 45.00 450.00 360.00 2034.00 480.00 33.11 1525.00 10.00 Min 6.94 1023.00 1598.00 27.00 131.00 0.33 40.00 18.00 159.70 96.00 0.00 414.00 1.08 Average 7.43 2838.33 4429.83 27.97 516.43 9.75 180.87 150.67 868.47 234.93 9.77 892.36 3.36

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Table No.19: The calculated saturation indices (SI) of fluorite (CaF2) and calcite (CaCO3) in the groundwater samples from Hidhran & Al Burayhi Basin

Sample ID F Sum of Anions Sum of Cations SI (Calcite) SI (Fluorite) mg/l meq/l meq/l A-008 3 39.96104 39.85588 0.388 -0.1968 A-25 2.81 42.19401 42.17257 0.5319 -0.192 A-39 5.45 76.94215 76.61985 0.4072 0.416 A-42 2.793 43.79015 43.553 0.5879 -0.5373 A-43 1.995 19.26532 19.21264 0.5832 -0.8412 A-46 2.793 38.29745 38.18385 0.9514 -0.5942 A-5 5.8 15.89709 15.79815 0.3057 0.4073 A-51 3.667 50.07282 49.89928 0.8319 -0.1252 A-52 3.325 48.30266 48.12156 0.5172 -0.1958 A-53 1.729 17.20636 17.18969 1.0775 -0.4743 A-59 4.33 64.13435 63.77874 0.8008 0.3376 A-6 5.8 37.56781 37.50317 0.5529 0.2011 A-61 3.99 32.8698 32.79223 0.4658 0.4205 A-62 2.261 21.59492 21.58315 0.5429 -0.1922 A-65 3.33 39.9861 39.76565 0.736 0.2033 A-70 1.083 29.20981 29.14962 0.6026 -0.669 A-74 2.66 36.48774 36.38493 0.5217 0.0364 A-8 10 80.1766 79.83786 0.6537 0.997 B-004 2.66 38.98166 38.8393 0.6951 -0.2311 B-107 3.819 53.81306 53.63003 1.1816 0.309 B-115 1.37 23.19495 22.95746 0.9203 -1.1823 B-16 1.33 19.38195 19.32958 0.6268 -0.5024 B-26 1.425 18.74793 18.7055 0.6926 -0.6754 B-27 5.05 88.77073 88.51669 1.0711 0.5506 B-30 4.921 67.83682 67.46592 0.7739 0.2843 B-33 2.66 63.01542 62.56424 0.9795 -0.0512 B-40 1.672 41.72055 41.40937 0.9743 -0.2469 B-41 3 52.10859 51.95129 0.8745 0.374 B-54 1.33 59.71292 59.41804 1.4702 -0.4948 B-92 4.864 68.30481 67.91173 0.6718 0.3337 B-98 4.008 60.82332 60.54231 0.8557 0.0227

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Table No.20: Chemical analysis of spring water samples from Jabal Sabir Area (June 2009)

X Y Station ID Ph E.C TDS Ca Mg Na K Cl NO3 SO4 HCO3 TDS F

394169 1498869 1 7.7 730 474.6 44 11 157 0.6 106 123 33 230 474.6 2.3

393780 1498814 2 7.3 450 292.4 27 8 113 0.4 80 48 16 290 292.4 2.08

393558 1497222 3 7.4 420 273.3 34 4 70 0.3 60 97 8 380 273.3 1.2

395031 1497347 4 7.2 334 217.3 33 6 70 0.3 60 40 8 380 217.3 1.6

392287 1499062 5 7.8 1004 652.6 48 8 178 0.6 98 54 23 243 652.6 2.01

396408 1497767 6 7.1 896 582.5 35 6 76 0.5 64 30 15 356 582.5 1.1

397860 1496015 7 7 667 433.3 25 4 66 0.3 57 22 9 250 433.3 0.52

398907 1497417 8 7.5 996 647.1 37 9 110 1.1 83 81 21 305 647.1 1.8

397783 1497762 9 7.9 914 594.3 33 7 68 0.3 60 42 8 376 594.3 2.2

396661 1498618 10 7.8 942 612.4 35 7 103 0 77 55 16 320 612.4 2.18

Max 7.9 1004 652.6 48 11 178 1.1 106 123 33 380 652.6 2.3

Min 7 334 217.3 25 4 66 0 57 22 8 230 217.3 0.52

Average 7.47 735 477.98 35.10 7.00 101.10 0.44 74.50 59.20 15.70 313.00 477.98 1.70

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Table No.21: The calculated saturation indices (SI) of fluorite (CaF2) and calcite (CaCO3) in the spring water samples from Jabal Sabir Area

Station ID F Sum of Anions Sum of Cations SI (Calcite) SI (Fluorite) mg/l meq/l meq/l 1 2.3 9.14473 9.945353 -0.5868 -0.4859 10 2.18 8.569504 6.802861 -0.509 -0.585 2 2.08 8.067457 6.931134 -0.6579 -0.7322 3 1.2 9.393504 5.078347 -0.4516 -1.1181 4 1.6 8.68383 5.19302 -0.4483 -0.8633 5 2.01 8.023969 10.81155 -0.5074 -0.5405 6 1.1 8.394642 5.558927 -0.4508 -1.1627 7 0.52 6.201892 4.455233 -0.719 -1.9201 8 1.8 8.910391 7.399859 -0.5179 -0.7446 9 2.2 8.675496 5.188312 -0.4536 -0.5889

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Appendix 3

Severe Dental Flourosis

Mild Dental Flourosis

Moderate Dental Fluorosis

Photo No.1: Mild, Moderate and Severe Dental Fluorosis in Children from Photo No.2: Moderate/to Severe Dental Fluorosis (8 Hidhran Primary School (2009) Years Old)

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Photo No.3: Mild to moderate Dental Fluorosis from Photo No.4: Moderate to Severe Dental Fluorosis (10 Al Howban Basin years old) From Al‐ Howban Basin.

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Photo No.5: Severe Dental Fluorosis (9 years old) from Jabal Sabir Photo No.6: Moderate Dental Fluorosis (7 Years Old) from Area Jabal Sabir area.

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Photo No.7: Severe to Moderate Dental Fluorosis (17 years Photo No.8: Mild to Moderate Dental Fluorosis (8 years old) Jabal Sabir old) from Jabal Sabir Area area

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Photo No.9: Man‐made terraces in Jabal Sabir Photo No.10: Field kits for Fluoride testing

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