Tooth analyses of sources and intensity of lead exposure in children.
Tooth analyses of sources and intensity of lead exposure in children.
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DOI：
10.1289/ehp.96104306
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发表时间：
1996-03
影响因子：
10.4
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中科院分区：
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使用稳定的铅同位素比值和铅浓度的切牙和乳牙的颈部部分从30个暴露和非暴露的儿童从布罗肯希尔铅采矿社区在澳大利亚的来源和强度的铅暴露在子宫内和幼儿期。切割部分，主要由釉质组成，通常有少量的铅和同位素组成，与怀孕期间母亲的预期一致。宫颈部分，主要由牙本质与次生牙本质去除吸收和铰，一般有较高的铅含量比釉质和同位素组成的来源，出生后暴露一致。对于低铅暴露和高铅暴露的儿童（分别为p = 0.0007，2 x 10（-6））和摄入含铅油漆的儿童（p = 0.009），切部和颈部切片之间的铅浓度存在统计学显著差异，代表牙齿内的变化。这三个暴露组中的切缘和宫颈切片之间的统计学显著差异也通过三组铅同位素比率（例如，p = 0.001（低暴露组中206 Pb/204 Pb比值）。低铅暴露组和高铅暴露组在切缘（铅浓度p = 0.005，206 Pb/204 Pb比值为6 x 10（-6））和宫颈切片（铅浓度p = 5 x 10（-5），206 Pb/204 Pb比值为6 x 10（-6））中的铅浓度和同位素比值存在统计学显著差异。牙质结果反映了儿童早期铅-锌-银矿物存款（矿体铅）的暴露增加，可能与手到口的活动。在至少两个病例中，含铅油漆被确定为牙铅升高的来源。在两个案例中，涉及到子宫内来自矿体和油漆来源的铅暴露增加，但没有迹象表明母亲目前的血铅曾暴露于铅，这表明母亲的急性暴露而不是慢性暴露。一个受试者的恒牙根部的铅含量低于牙冠，牙冠的同位素组成与同一受试者乳牙的数据一致。根据牙釉质和牙本质的同位素组成的变化，初步估计铅以每年约2-3%的速度添加到牙本质中。
The sources and intensity of lead exposure in utero and in early childhood were determined using stable lead isotopic ratios and lead concentrations of incisal and cervical sections of deciduous teeth from 30 exposed and nonexposed children from the Broken Hill lead mining community in Australia. Incisal sections, consisting mostly of enamel, generally have low amounts of lead and isotopic compositions consistent with those expected in the mother during pregnancy. Cervical sections, consisting mostly of dentine with secondary dentine removed by resorption and reaming, generally have higher amounts of lead than the enamel and isotopic compositions consistent with the source of postnatal exposure. There are statistically significant differences in lead concentrations between incisal and cervical sections, representing within-tooth variation, for children with low and high lead exposure (p = 0.0007, 2 x 10(-6), respectively) and for those who have ingested leaded paint (p = 0.009). Statistically significant differences between incisal and cervical sections in these three exposure groups are also exhibited by the three sets of lead isotope ratios (e.g., p = 0.001 for 206Pb/204Pb ratio in the low exposure group). There are statistically significant differences between the low and high lead exposure groups for lead concentrations and isotopic ratios in incisal (p = 0.005 for lead concentration and 6 x 10(-6) for 206Pb/204Pb ratio) and cervical sections (p = 5 x 10(-5) for lead concentration and 6 x 10(-6) for 206Pb/204Pb ratio). The dentine results reflect an increased exposure to lead from the lead-zinc-silver mineral deposit (orebody lead) during early childhood, probably associated with hand-to-mouth activity. Leaded paint was identified as the source of elevated tooth lead in at least two cases. Increased exposure to lead from orebody and paint sources in utero was implicated in two cases, but there was no indication of previous exposure from the mothers' current blood leads, suggesting an acute rather than a chronic exposure for the mothers. Permanent teeth from one subject had lower amounts of lead in the roots compared with the crowns, and the isotopic composition of the crowns were consistent with the data for the deciduous teeth from the same subject. Based on changes in the isotopic composition of enamel and dentine, it is provisionally estimated that lead is added to dentine at a rate of approximately 2-3% per year.