The onset of menstruation in girls was selected as an index of the rate of sexual maturation, since the menarche is an event which is usually readily dated. The distribution of ages at the nearest birthday at which menstruation first occurred is shown in Table 5. The average age at the menarche was 12 years among the girls studied in Newburgh and 12 years 5 months among the girls in Kingston. No statistical significance could be demonstrated in this difference, nor in the difference between the two cities in the proportion of girls who had passed the menarche. . . .
This report on the findings on the general medical and related examinations during the ten years of the Newburgh-Kingston Caries-Fluorine Study emphasizes the examinations performed ten years after the start of fluoridation of the water supply of Newburgh. At the time the study was proposed, all the scientific evidence available pointed to the safety of drinking water containing about 1.0 ppm of fluoride at the source. There was no reason to believe that fluoride, when added to the drinking water as part of the water treatment process to make up for a deficiency of fluoride, would act in any way differently from fluoride already present. Nevertheless, it was considered desirable to test this remote possibility under the carefully controlled conditions established for the Newburgh-Kingston study.
Closely similar groups of children were studied in Newburgh and Kingston. Excluding those children who dropped out for any reason during the course of the study, 500 of the children enrolled in the study in Newburgh and 405 in Kingston were seen in the final series of examinations. The children in Kingston, where the drinking water supply has been essentially fluoride-free, served as controls for the Newburgh children who drank water fluoridated at a level of 1.2 ppm. No differences of medical significance could be found between the two groups of children; thus further evidence was added to that already available on the safety of water fluoridation.
The examinations performed in the tenth year of the study may be summarized briefly. Each child was given a general medical examination by a qualified pediatrician. Height and weight were measured. Roentgenograms were taken of the right hand, both knees and the lumbar spine, and the bone density and bone age (maturation of the skeleton) were estimated. Laboratory examinations, including hemoglobin level, total leukocyte count and routine urine analysis, were also made. In addition, special studies were performed on smaller groups of children. These studies included detailed examinations of the eyes and ears, with determination of visual acuity, visual fields and hearing levels, and studies of the quantitative excretion of albumin, red blood cells, and casts in the urine.