Effect of excess Fluoride consumption on Urine-Serum Fluorides, Dental state and Thyroid Hormones among children in 'Talab Sarai' Punjab Pakistan

190 children aged 7-18 years from an endemic fluorotic village “Talab Sarai (n = 130) and a non-fluorotic, control, village “Ottawa” (n = 60) were selected for comparison. Children were examined for fluoride (F-) concentration in drinking water, urine, and serum as well as Dental fluorosis (DF) and thyroid hormone levels. The mean concentration of water fluoride (WF) in the sample group was 6.23 mg/L, urine fluoride (UF) 3.38 mg/L, and serum fluoride (SF) 0.21 mg/L, while DF was 93.07%. Significant elevations (P = 0.000) in the concentration of all these four variables were observed in sample group children as compared to control. Mean Free Tetra-iodothyronine (FT4), Free Tri-iodothyronine (FT3) and Thyroid Stimulating Hormone (TSH) concentrations in the sample group were 16.64pmol/L, 5.57 pmol /L and 4.41 mlU/L, respectively. No marked difference in FT4 (P = 0.1) was noted, while significant elevations in FT3 and TSH (P = 0.000) were found in the sample relative to the control group. 80% of the children displayed clear thyroid hormonal derangements, with 36.92% having high TSH and 43.07% with FT3 and FT4 disorders. A moderate to strong correlation among WF, UF, SF and DF (r = 0.94, 0.60, 0.60, 0.72) and a very strong correlation between WF and TSH (r = 0.9) were observed. Our results suggest that excess F- level that is four times greater than the “safe limit” is not only increasing fluoride concentration in body fluids but is also affecting thyroid hormones in 4 out of 5 children which could lead to abnormal physical and mental growth in later developmental stages.