Fluoride Toxicity in the Fluoride Endemic Villages of Gaya District, Bihar, India - Management of Natural Resources in a Changing Environment - page 266

where C =F concentration (mg/L), WI =water intake (l/day) and BW = body
weight (kg).
The water intake was estimated from the information collected during the health
survey. The average water intake for children was 2 l/day and that for adults was
4 l/day. Average body weight of children was taken as 20 kg and that of adults was
taken as 60 kg. Statistical analysis was performed with t-test.
Results and Discussion
Fluoride concentration in the groundwater of different blocks is presented in Table 1 .
None of the samples of Bodh Gaya and Belaganj blocks had F above the desirable
limit of 1.0 mg/L as suggested by BIS 2003. In Manpur block, Mayapur village had
F level of 1.1 mg/L. In Wazirganj block, Bharaiti (1.7 mg/L) and Karhauna
(1.6 mg/L) villages recorded higher fl uoride concentration (i.e. above the WHO
permissible limit). Amas and Bankebazar blocks were endemic with respect to fl uo-
ride contamination of groundwater, with F level ranging 0.47-6.3 mg/L. The mean
pre-monsoon F level in groundwater (1.05 ± 0.09, N = 123) was insignifi cantly dif-
ferent from mean post-monsoon F level (1.02 ± 0.08, N = 123).
A positive correlation was found between pH and fl uoride which indicates that
alkaline nature of the water promotes leaching of fl uoride from rocks (Table 2 ). The
alkaline water can mobilize fl uoride from rocks with precipitation of calcium car-
bonate because the solubility of fl uorite (CaF 2 ) increases with an increase in
NaHCO 3 rather than with other salts (Handa 1975 ; Saxena and Ahmed 2001 ;
Sunitha et al. 2012 ). A negative correlation was found between the Ca ( r = -0.4), Fe
( r = -0.2) as well as Mg ( r = -0.2) and F levels in the water samples. This indicates
low solubility of F with these ions (Das et al. 2003 ).
The F level in serum and urine were signifi cantly higher in the fl uorotic individu-
als as compared to control (Table 3 ). According to Susheela et al. ( 2005 ), normal
upper limit of fl uoride in serum and urine should be 0.02 mg/L and 0.1 mg/L respec-
tively. Residents of Amas (Bhoop Nagar, Masooribaar) and Bankebazar block
(Dhaneta, Bhaktauri) were found to suffer with skeletal fl uorosis (children 80 %,
adult males 52 % and adult females 33 %) and dental fl uorosis (children 87.6 %,
adult males 79 % and adult females 59.7 %) (Table 4 , Fig. 1 ). Residents of F endemic
areas also complained of gastro-intestinal and neurological problems (i.e. headache
and insomnia). In Dhaneta village of Bankebazar block, 55 % adult males, 63 %
adult females and 35 % of children suffered with neurological problems, while in
Bhaktauri village of Bankebazar block, 71 % adult males and 75 % adult females
suffered with headache and insomnia. In Bhupnagar village of Amas block, 88 % of
adult males, 76.3 % of adult females and 50 % of children were found to have neu-
rological problems. It has been found that F can reduce levels of melatonin, the
sleep hormone, in the body, causing chronic insomnia (Hileman 1988 ). Spittle
( 1994 ) also recorded cases of severe headache in adult subjects exposed to F in their
drinking water. Sharma et al. ( 2009 ) found an increase in the severity of neurological