Azcona-Cruz M I, Rothenberg S J, Schnaas-Arrieta L, Romero-Placeres M, Perroni-Hernández E
Instituto Nacional de Salud Pública (INSP), México.
Salud Publica Mex. 2000 Jul-Aug;42(4):279-87.
To assess the association between blood lead concentrations and visual-motor coordination and equilibrium in school age children.
In November-December 1998, a cross-sectional study was conducted among 255 children aged 8-10, who attended public schools in Sector 1 of the Oaxaca State Public Education Institute. Data were collected using the Frostig Evaluation of Visual Perception test and the equilibrium subscale of the Frostig Movement Skills Test Battery. A blood sample was taken to measure lead levels by atomic absorption spectrometry. Socioeconomic data and health histories were collected for use as control variables. Statistical analysis consisted of multiple regression models to test the relationship between blood lead level and the visual-motor and equilibrium tests. We assessed the effect of lead within the model using 1,000 Montecarlo simulations.
The geometric mean of blood lead concentrations was 11.5 micrograms/dl (geometric standard deviation +6.3, -5.2). After adjusting for control variables, the visual-motor integration subscale was significantly related to blood lead concentration (p > 0.042). The visual-motor integration value decreased 1.78 (95% CI -3.51, -0.06) points for each 10 micrograms/dl increase in blood lead concentration. Among the four sub-tests comprising the visual-motor integration subscale, only eye-hand coordination (p = 0.045) and spatial relations (p = 0.039) were significantly related to blood lead. The visual-motor integration subscale was also significantly related to family income; greater income was related to greater testing scores. Only 3.1% of the children had clinically abnormal testing scores. No statistically significant association was found between blood lead levels and the Frostig subscale Index of Reduced Motor Response, the General Visual Perception Index, or any other equilibrium tests.
The inverse relationship between blood lead concentration and visual-motor skill is consistent with results from studies in other countries. Blood lead levels common among children of Oaxaca are sufficient to produce subtle visual-motor impairments. These findings point out the need to strengthen the initiative to reduce child exposure to known lead sources, particularly lead-glazed ceramics, and thus lower the blood lead levels of the population.
评估学龄儿童血铅浓度与视动协调及平衡能力之间的关联。
1998年11月至12月，对瓦哈卡州公共教育机构第1区公立学校的255名8至10岁儿童进行了一项横断面研究。使用弗罗斯蒂格视觉感知测试和弗罗斯蒂格运动技能测试电池的平衡分量表收集数据。采集血样，通过原子吸收光谱法测量铅水平。收集社会经济数据和健康史作为控制变量。统计分析包括多元回归模型，以检验血铅水平与视动及平衡测试之间的关系。我们使用1000次蒙特卡洛模拟评估模型中铅的影响。
血铅浓度的几何平均值为11.5微克/分升（几何标准差+6.3，-5.2）。在对控制变量进行调整后，视动整合分量表与血铅浓度显著相关（p>0.042）。血铅浓度每升高10微克/分升，视动整合值下降1.78（95%可信区间-3.51，-0.06）分。在构成视动整合分量表的四个子测试中，只有眼手协调（p=0.045）和空间关系（p=0.039）与血铅显著相关。视动整合分量表也与家庭收入显著相关；收入越高，测试分数越高。只有3.1%的儿童临床测试分数异常。在血铅水平与弗罗斯蒂格运动反应降低分量表指数、一般视觉感知指数或任何其他平衡测试之间未发现统计学上的显著关联。
血铅浓度与视动技能之间的负相关关系与其他国家研究结果一致。瓦哈卡州儿童中常见的血铅水平足以产生轻微的视动障碍。这些发现指出有必要加强减少儿童接触已知铅源（特别是铅釉陶瓷）的举措，从而降低人群的血铅水平。
