Fluoride Contamination of Ground Water in INDIA

RG Segaran, M.Tech (Env) , MBA (Mtg) FIE (India), Fulbright Fellow (USA)

Email: segaranrg@gmail.com

1.0 Introduction

Although India has substantial fresh water resources, there is an acute shortage

of safe drinking water of acceptable quality, specially in rural areas. The socio

economic growth of a region is severely constrained by non availability of safe

drinking water. Keeping this in view Government of India constituted technology

mission for drinking water in 1987. Fluoride in the ground water was one of the

specific problems considered by the mission. High fluoride in ground water

causes health hazard.

Fluoride is considered to be beneficial for human health if taken in controlled

quanity (1.0 – 1.5 mg/L) preventing dental caries and is known to cause dental

and skeletal fluorosis when present in concentration greater than 3.0 mg/L. Many

studies on fluoride content of water in India have been carried out on an

incidence of fluorosis is reported to be associated with high concentration of

fluoride in drinking water.

According to WHO, one hospital bed out of four in the world is occupied by a

patient who is ill because of polluted water. Fluorosis in drinking water is

important because it has a definite relation to dental health.

It has been reported that fluoride in drinking water is known to prevent the

development of dental caries when this level lies between 0.6 – 1.5 ppm. At

these level which are apparently safe in countries, like USA and Japan, dental

mottling is seen in some other countries. In countries, like India and South

Africa, the problem of fluorosis has been attributed to mainly ground water

fluoride.

The incidence of high fluoride content in ground water and the apparent

correlation between the high fluoriosis prompted the ground water quality

monitoring and investigation on fluoride content of ground water.

Fluorosis is one of the most crippling endemic diseases affecting million of

people in different parts of the world. In India the disease was first discovered in

the Madras province in 1937 later the disease was also identified from different

states. At present more than 30 million people in 13 states are to be affected by

this disease .

High fluoride concentration has been found in ground water in parts of Andhra

Pradesh, Bihar, Gujarat, Haryana , Karnataka, Kerala , Madhya Pradesh ,

Maharashra, Punjab, Rajasthan , Tamil Nadu and Uttar Pradesh.

Following Table indicates the high incidence rate of Fluoride in Ground water in

different states in India;

State Name of district Average fluoride level mg / L level

Tamil nadu Chengalpet

Salem

Madurai

Tiruchirapalli

Coimbatore

4.5

Karnataka Belgaum 0.8-1.2

Andhara Pradesh West Godavari

Nalagonda

Nellore

Anantapur

0.8-1.2

Gujarat Mehsana

Banaskentha

Saberkantha

Panch Mahal

Surat

4.0

Punjab Bhatinda

Ferozpur

Amritsar

3.0

Haryana Gurgaon

Hissar

Karnal

3.6

2.0 Tamil Nadu

In Tamil Nadu, the high concentration of fluoride in groundwater is found to be in

Dharmapuri and Salem district closely followed by Coimbatore, Madurai, Trichy,

Dindukal and Chidambaram district.

S.no Status Districts

1 Severe Dharmapuri,Salem,

2 moderate Coimbatore,Madurai,Trichy,Dindugal,Chidambaram

3 Less Thirunelveli,Pudukottai,North Arcot,Ramned

An attempt has been made to assess the prevalence of fluoride among school

children in virudhungar district. Besides an analysis if fluoride ion in the water

samples other water quality parameters in Virudhunagar district. Dental fluorosis

survey was carried out at different schools in Sivakasi and Mamsapuram in

virudhuagar district.

The results of the study were correlated with water quality parameters. Including

fluoride content in 23 samples were collected. The maximum fluoride ion

concentration is found to be 1.8 mg/L at Sivakasi and Mamsapuram. This is due

to the presence of natural resources around these areas. These area people

depend on ground water for drinking as well as cooking.

Incidence of fluorosis in ten villages near Tuticorin, Tamil nadu, India has been

carried out. The prevalence of fluorosis in twenty villages of Manur Bloc,

Tirunelveli, Kattabomman Districts are also reported. Tirunelveli District of

Tamilnadu in South India is reported to have drinking water containing high levels

of fluoride and causes disease namely fluorosis. The water samples in the

Palacode area evidenced excess fluoride concentrations and were not meeting

the BIS/ WHO standards. The samples abstracted from groundwater that is used

for drinking purposes showed high fluoride concentration resulted in dental

fluorosis among the local residents. The excess fluoride concentration in

Palacode area may be attributed to the geological formation and recent

exploitation of groundwater. In fact, if the fluoride level in drinking water is more

than 1.5 mg/l, risk of endemic fluorosis will exist.

3.0 Andhra Pradesh

The prevalence of fluorosis was detected for the first time in India in Padli and

Darsi ranges of Nellore district.

An investigation on groundwater quality with reference to Flouride concentration

in rural parts of Guntur district, Andhra Pradesh, India indicates that the ground

water is alkaline, of medium to very hard category and mostly brackish.

Weathering and leaching of Flouride bearing minerals under the alkaline

environment account for the enrichment of Flouride in the ground waters. A high

rate of evapo transpiration, long-term contact of waters in the weathered zone by

virtue of its low hydraulic conductivity and stagnation of water in the aquifer zone

caused by intrusive bodies, intensive and long term irrigation, and heavy use of

fertilizers are the supplementary factors to further increase the Flouride content

in the groundwater.

In 45% of the total groundwater samples, the Flouride content is higher than the

maximum permissible limit (1.20 mg/l). High fluoride concentrations groundwater

suggest that favorable conditions exists for the dissolution of fluoride bearing

minerals present in the granite and gneissic rocks in the study area. Fluoride

bearing minerals occupy the joints, fractures, faults and vertical openings in the

gneissic and granitic formations which are the oldest geological formations in

Anantapur and have undergone maximum weathering.

4.0 Rajasthan

In Rajasthan a heterogenous pattern of fluoride distribution has been observed in

18 districts. A total of 270 drinking water sources were examined for the evidence

of fluoride 64% showed the presence of excess fluoride with varying ranges.

Fluorides are normally present in groundwater and as high as 90 mg/L of fluoride

has been reported in groundwater in Western Rajasthan.

5.0 Orissa

As is other parts of the country ground water constitutes the main source of

drinking water in Orissa. But high concentration of fluoride in ground water,

though in localized pockets in Orissa State is a matter of great concern. It is

observed that 81.3% samples of ground water from shallow aquifers (tapped in

dug well and hand pump fitted tubewells) contain less than 1.0 mg/L, 7.86% are

within 1.5mg/L and 10.83% are above 1.5 mg/L.

In some cases high fluoride contents have also been recorded in ground water of

deeper aquifers. Studies point to a geological source of fluoride. The area

around Anugul, Dhankenal destruct has a number of industrial establishments

namely NALCO smelter plant NALCO captive power plant Talcher Thermal

power station. Fertilizer corporation of India, etc These industries are discharging

significant load of effluent wastes even through suitably treated. There are

reports of high fluoride content in the ground water of the area.

In the undivided districts of Bolangir, Kalahandi, Phulbani, Puri, Sambalpur and

Sundergarh fluoride contents of more than 1.5 mg/L have been found in number

of cases.

The high values of fluoride observed in Balasore, Puri, Cuttack districts in

shallow and deep alluvial aquifers. Around Balasinghi and Singhipur in Bolagarh

block, Khurda district occurrences of high fluoride in ground water have been

noticed, causing severe fluorisis accompanied by skeletal deformities. The

villages having high fluoride in ground water include Jariparha, Sagaragan,

Singhpur – Balasinghi, Singhipur.

The undivided districts of Bolangir, Kalahandi, Balasore, Cuttack, Dhenkanal,

Phulbani, Puri, Sambalpur and Sundergarh need a special mention in this

respect. High fluoride content upto even 16 mg/L has been recorded in ground

water in these districts.

6.0 Uttar Pradesh

Fluoride concentration and other water quality parameters in groundwater

samples from 77 villages in block Akola of Agra District were assessed. The

maximum fluoride concentration recorded was 22.0 mg/L in this area. Only 45%

samples were found suitable for drinking purposes considering fluoride levels in

them.

In Agra district of Uttar Pradesh, most of the villages depend on groundwater for

their drinking and other requirements. In view of the reported presence of dental

and skeletal fluorosis in the rural population of district Agra and on account on

lack of data on the fluoride content of their drinking water, an extensive survey of

water quality in block Akola consisting of 77 villages, having a population of

about 2 lakh has been performed. Water samples from almost all the drinking

sources (hand-pump, openwall,tubewell) were collected from all the villages of

this block.

In all 307 water samples from all the drinking water sources from 77 villages in

block Akola were collected. In all 307, samples were analysed for fluoride. The

fluoride concentration in groundwater of the study area ranged from 0.28 to 22.0

mg/L. Of the samples analysed 138 samples (45%) were in the range of 0 – 1.0

mg/L. The highest concentration recorded was 22.0 mg/L in one sample,

collected from an open well at Bainkhera village.

7.0 Madhya Pradesh

The grand chain of Satpura Mountain is situated in between Narmada and Tapti

rivers in Central India. The total mountain area of this valley is 75000 Sq. km.

Some water samples were collected from industrial, urban and adjoining areas of

tribal towns and villages of satpura valley to detect the concentration of fluorides.

All the available drinking water resources have been identified and determined

the fluoride ion concentration in some water sample have been found 2-5 times

higher than WHO STANDARDS

The fluorides ion concentration in underground water and river water near

industrial area of satpura region are 2- 5 times higher that ISI permissible limits.

This higher concentration of fluoride is due to the discharges from industries,

phosphatic fertilizers used in agricultural lands, weathering of rocks and highly

contaminated sewage water.

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