Fluoride Toxicity in the Fluoride Endemic Villages of Gaya District, Bihar, India - Management of Natural Resources in a Changing Environment - page 268

Table 2 Correlation of different parameters in pre-monsoon (a) and post-monsoon (b) groundwater
samples

Total
Hardness
(TH) Turbidity pH EC TDS Fluoride Calcium Iron Mg

(a)
Turbidity

0.08 −0.02 −0.01 −0.005 −0.15 −0.11 0.64 −0.105

pH 0.08 0.07 0.06 0.54 −0.15 −0.35 −0.17 −0.09

EC −0.02 0.07 0.99 0.02 0.71 0.53 −0.13 0.64

TDS −0.01 0.06 0.99 0.01 0.71 0.53 −0.12 0.64

Fluoride −0.005 0.54 0.02 0.01 −0.33 −0.42 −0.25 −0.22

TH −0.15 −0.15 0.71 0.71 −0.33 0.78 −0.11 0.74

Calcium −0.11 −0.35 0.53 0.53 −0.42 0.78 0.04 0.67

Iron 0.64 −0.17 −0.13 −0.12 −0.25 −0.11 0.04 −0.08

Mg −0.10 −0.09 0.64 0.64 −0.22 0.74 0.67 −0.08

(b)
Turbidity 0.12 −0.03 −0.04 −0.05 −0.17 −0.21 0.56 −0.09

pH 0.12 0.15 0.16 0.24 −0.02 −0.24 −0.13 −0.04

EC −0.03 0.15 0.99 0.01 0.71 0.49 −0.13 0.63

TDS −0.04 0.16 0.99 0.02 0.71 0.48 −0.13 0.62

Fluoride −0.05 0.24 0.01 0.02 −0.34 −0.42 −0.27 −0.25

TH −0.17 −0.02 0.71 0.71 −0.34 0.77 −0.11 0.73

Calcium −0.21 −0.24 0.49 0.48 −0.42 0.77 −0.05 0.68

Iron 0.56 −0.13 −0.13 −0.13 −0.27 −0.11 −0.05 −0.05

Mg −0.09 −0.04 0.63 0.62 −0.25 0.73 0.68 −0.05

ailments with the increase in F concentration in drinking water. The occurrence of
gastro-intestinal complaints is considered to be the early warning signs of F toxicity
(Susheela et al. 1992 ). F causes serious damage to the gastrointestinal (GI) mucosa
by destroying the microvilli resulting in non-absorption of nutrients from the diet
(Susheela et al. 1992 ; Das et al. 1994 ).
Biochemical analysis showed elevated TT3 in all the age/sex groups and elevated
TT4 and TSH level in children of F endemic areas as compared to control subjects
(Table 5 ). This suggests that F can induce thyroid dysfunction. Previous studies
indicated that excessive F, with or without adequate iodine (I) intake, was a signifi -
cant risk factor for the development of thyroid dysfunction (Liu et al. 2002 ; Ge et al.
2005a , b ). Hypocalcemia was found in the adults of F endemic area, while hypogly-
cemia was found in both adults and children of F endemic areas. Hypocalcemia
could be due to a decrease in the intestinal absorption of calcium since fl uoride is
known to produce insoluble complexes with calcium. Similar fi ndings were also
reported by Michael et al. ( 1996 ) and Barot ( 1998 ). Fluoride toxicity leads to a
number of adverse effects including hypoglycemia (B

ă

lan 2012 ).
The haematological analysis of residents of F endemic villages showed lowered
Hgb level in all the adult residents (Table 6 ). F may cause the erythrocyte membranes