Needleman H L
School of Medicine, Western Psychiatric Institute and Clinic, University of Pittsburgh, PA 15213.
Environ Health Perspect. 1990 Jun;86:183-9. doi: 10.1289/ehp.9086183.
The history of knowledge about lead toxicity may serve as a useful template to judge and predict progress in understanding other toxicants. A paradigm shift has occurred in which toxicity has been recognized at levels long held to be harmless. This shift has been accelerated by the use of newer tools for measuring outcome. Lead effects have been identified in children at blood lead levels as low as 15 micrograms/dL. They include impaired psychometric intelligence, language function, attention, and classroom behavior. Lead exposure during pregnancy results in increased risk for minor malformations and lowered infant IQ scores until at least 2 years of age. Understanding of this toxicant has been blurred by seven unrecognized Type II errors frequently encountered in the lead literature. These errors are discussed. A meta-analysis of thirteen informative lead studies in children is presented. The joint probability of the findings occurring by chance under the null hypothesis is less than 3 x 10(-12).
关于铅毒性的知识史可作为一个有用的模板，用于判断和预测在理解其他有毒物质方面的进展。已经发生了范式转变，即毒性在长期以来被认为无害的水平上就已被认识到。使用更新的测量结果工具加速了这一转变。血铅水平低至15微克/分升的儿童已被发现有铅影响。这些影响包括心理测量智力受损、语言功能、注意力和课堂行为受损。孕期铅暴露会增加轻微畸形的风险，并降低婴儿智商分数，至少在2岁之前如此。铅文献中经常遇到的七个未被认识到的II型错误使对这种有毒物质的理解变得模糊。对这些错误进行了讨论。还对十三项关于儿童的铅信息研究进行了荟萃分析。在零假设下，这些发现偶然出现的联合概率小于3×10⁻¹²。
