Studies on fluoride distribution in infants and small children.

The fluoride (F) concentrations in hard tissues and blood plasma were determined in biopsy and autopsy specimens from fetuses, infants, and children on varying F intake. In newborn autopsy cases specimens consisting of rib, jawbone with teeth, and blood plasma the F concentrations of bone and dentin were of the same order, those of the enamel lower. Correlations between individual F values in different tissues were all positive, highest for enamel/dentin. Low birth weight entailed only slightly reduced F contents, high water F significantly increased F contents. In the biopsy material (rib and blood plasma) the maximal rib/ash concentration was about 400 parts/10(6) F. A negative correlation between rib F and plasma F is specially commented on. The possible influence of F on bone development as expressed by blood plasma F and phosphatase activity was investigated in three groups of infants aged 2-6 months, either breast-fed or fed dry-milk formulas diluted with drinking waters of different F content. The children of these groups were calculated to ingest F in the ratio of about 1:10:50. The highest F group had higher plasma F values than the two other groups, whereas its alkaline phosphatase was significantly higher than that of the lowest F group only. The influence of disturbances in the skeletal development on F retention studied in physically handicapped children aged 4-15 years living in a city with about 1 part/10(6) F in the drinking water. The severely handicapped showed a higher urinary F excretion than the controls.