Padich R A, Dietrich K N, Pearson D T
Environ Res. 1985 Oct;38(1):137-43. doi: 10.1016/0013-9351(85)90079-9.
A structured problem-solving task was used to evaluate the effects of lead (Pb) exposure on the activity patterns and attention of 18-month-old infants. After statistically controlling for the influence of the caretaker's attempts to support and teach the infant during the task, multivariate techniques were used to examine the residual variances to detect any effects of prenatal or postnatal Pb exposure. Contrary to expectations, no relationship was found between Pb exposure and measures of attention. Activity level was found to be negatively related to blood Pb level. The suggested suppression of behavior was inconsistent with reports of hyperactivity found in school children with elevated Pb level, but is consistent with observations of lethargy in infants with iron deficiency. To examine this alternative, free erythrocyte protoporphyrin (FEP) levels, which are elevated both in the presence of elevated Pb and in iron deficiency, were incorporated into the regression model. FEP was the best predictor of room movement, as indicated by a backward elimination analysis that removed all Pb measures from the model. However, none of the other measures of hematopoietic status were related to behavior. The suppression of activity level, if a reliable effect, is very small, and only weakly though significantly related to FEP level.
一项结构化问题解决任务被用于评估铅（Pb）暴露对18个月大婴儿的活动模式和注意力的影响。在对任务期间看护人支持和教导婴儿的影响进行统计控制后，使用多变量技术检查剩余方差，以检测产前或产后铅暴露的任何影响。与预期相反，未发现铅暴露与注意力测量之间存在关系。发现活动水平与血铅水平呈负相关。所提示的行为抑制与血铅水平升高的学龄儿童中发现的多动报告不一致，但与缺铁婴儿的嗜睡观察结果一致。为了检验这种可能性，将在铅水平升高和缺铁时均会升高的游离红细胞原卟啉（FEP）水平纳入回归模型。如通过从模型中去除所有铅测量值的向后消除分析所示，FEP是室内活动的最佳预测指标。然而，造血状态的其他测量指标均与行为无关。如果活动水平的抑制是一个可靠的效应，那么它非常小，并且仅与FEP水平有微弱但显著的关系。
