ASSESSMENT OF LEAD-EXPOSURE OF CHILDREN FROM K-XRF MEASUREMENTS OF SHED TEETH

Lead is accumulated and immobilized for long periods of time in teeth. Thus the Pb concentration of a tooth can be used as an indicator of t he cumulative Pb intake of a child. Shed and extracted teeth were coll ected from children in Beijing, China and some industrial regions in t he Middle Urals in Russia. The Pb levels in the teeth were measured in Philadelphia, PA using an X-ray fluorescence (XRF) technique. Since P h deposits in the tooth during the entire period that it is in the chi ld, the measured tooth Pb level was divided by the age of the child wh en the tooth was shed and expressed in terms of (mu g/g-yr). 10% (n = 100) of the teeth from Beijing, China had Pb levels exceeding 5.5 and 3% above 9 mu g/g-yr. For comparison, in the 1970s when urban environm ental Pb levels were elevated, the tooth Pb levels in Philadelphia chi ldren were similar, i.e. 10% (n = 298) of the teeth had Pb levels exce eding 7.5 and 6% were above 9 mu g/g-yr. Children in a more rural sett ing, Bennington, VT, had no detectable tooth Pb (n = 200). The Pb leve ls in the teeth from the Urals were much higher; 50% (n =134) of the t eeth had Pb levels exceeding 7.5 and 10% exceeding 17.8 mu g/g-yr. The tooth Pb levels observed in the teeth from Beijing, and more so from the Urals, indicate that these children are residing in Pb polluted en vironments. Further studies are required to determine the extent of th e Pb pollution and to explore the possibility that there are associate d Ph-related health deficits. (C) 1998 Elsevier Science Ltd. All right s reserved.