Koren G, Chang N, Gonen R, Klein J, Weiner L, Demshar H, Pizzolato S, Radde I, Shime J
Department of Pediatrics, Hospital for Sick Children, Toronto, Ont.
CMAJ. 1990 Jun 1;142(11):1241-4.
Recent studies have suggested that a fetal blood lead level of 0.48 mumol/L (much lower than 1.21 mumol/L, which is the level previously believed to be toxic to the developing brain) may impair brain development permanently. We measured the maternal and umbilical cord blood levels of lead and free erythrocyte protoporphyrin (FEP) among 95 consecutive mother-infant pairs to determine whether neonates in Toronto are in the high-risk group. There was a significant correlation between the maternal and the cord blood lead levels (r = 0.59, p less than 0.0001). Most (99%) of the infants had cord blood lead levels below 0.34 mumol/L; in 11 cases the levels were below the detection limit of 0.01 mumol/L. The cord blood FEP levels were higher than the maternal levels. The US Centers for Disease Control, Atlanta, currently finds acceptable a blood FEP level of 0.62 mumol/L among children up to 10 years of age; however, this is not applicable to newborns since their higher FEP levels apparently reflect immature heme synthesis and increased erythrocyte volume rather than lead poisoning. Our data suggest that living in Toronto does not impose increased teratogenic risk from intrauterine exposure to lead; however, residents in high-risk areas should be followed up.
最近的研究表明，胎儿血铅水平为0.48微摩尔/升（远低于先前认为对发育中的大脑有毒性的1.21微摩尔/升）可能会永久性地损害大脑发育。我们测量了95对连续母婴的母体和脐带血中的铅及游离红细胞原卟啉（FEP）水平，以确定多伦多的新生儿是否属于高危群体。母体血铅水平与脐带血铅水平之间存在显著相关性（r = 0.59，p < 0.0001）。大多数（99%）婴儿的脐带血铅水平低于0.34微摩尔/升；11例婴儿的血铅水平低于检测限0.01微摩尔/升。脐带血FEP水平高于母体水平。美国亚特兰大疾病控制中心目前认为10岁以下儿童血FEP水平0.62微摩尔/升是可接受的；然而，这不适用于新生儿，因为他们较高的FEP水平显然反映了血红素合成不成熟和红细胞体积增加，而非铅中毒。我们的数据表明，生活在多伦多不会因子宫内接触铅而增加致畸风险；然而，高危地区的居民应接受随访。
