4. Discussion
Water-borne endemic fluorosis has been widely prevalent in China, especially in the central, western and northern parts of China. In order to explore the possible epigenetic changes caused by fluoride exposure, we conducted a screening and validation study in step by step. We undertook, for the first time, microarray analyses of DNA methylation on samples from school-age children who had been exposed to/not exposed to excessive fluoride in drinking water. Gradually, we conducted
Urinary fluoride measurement is the most useful biomarker to assess fluoride status [24, 61] as fluoride excretion is an indicator of fluoride intake [62]. AI of fluoride falls within the range of 0.05–0.07 mg/kg body/day weight in children less than 12 years of age, while UL is set at 0.1 mg/kg body weight/day [63, 64]. About 81.5% of children had estimated intake below 0.05 mg/kg boy weight per day and no one had an intake above the UL. The estimated intake of 0.032±0.031 mg/kg/day (median
Background:
This study determined the fluoride content of green tea from various parts of Asia, where green tea originates.
Methods
We brewed 2.5 g each of 4 types of green tea (from China, South Korea, Japan and Sri Lanka) using deionized water heated to boiling. Water was cooled to 71°C, then tea was steeped for 2 minutes. This process was repeated 20 times, thus providing 20 samples for each tea type. In addition, 20 control samples of deionized water were brewed to the same specificati
TABLE I
Showing Relation of Fluoride to Incidence of Mottled Enamel in Children
Composite of 9, 10, and 11
Year Old Children
City and State
Fluoride Content in p.p.m.
Number of
Children Examined
Incidence per
100 Children
Junction City, Kans.
0.7
115
1.7
East Moline, Ill.
1.5
110
24.5
Webster City, Iowa
1.6
72
26.4
Clovis, N. M
2.2
138
71.0
Plainview, Tex.
2.9
77
87.0
Amarillo, Tex.
3.9
229
89.5
Conway, S. C.
4.0
59
88.
