Carta P, Carta R, Girei E, Aru G, Flore C, Ibba A, Scaduto M T, Cadeddu C, Cocco S, Caracoi S, Sanna Randaccio F
Dipartimento di Sanità Pubblica-Sezione di Medicina del Lavoro, Università degli studi di Cagliari.
G Ital Med Lav Ergon. 2003 Jul-Sep;25 Suppl(3):43-5.
To estimate potential early adverse effects on the Central Nervous System (CNS) due to very low exposure to inorganic lead, the Intelligence Quotient (IQ) of adolescents with present blood lead concentrations (PhB) generally below 10 micrograms/dl was measured. We analyzed blood lead concentration and individual IQ of 32 Sardinian adolescents living in Portoscuso, a town 2 Km far from a lead smelter, and of other 32 controls living in S. Antioco, a town about 15 Km far from the same smelter. The Wechsler Intelligence Scale for Children Revised (WISC-R) was administered. The relation between IQ and blood lead concentration was estimated by linear multivariate models adjusting for several potential confounders, such as the educational and socio-economic level of the parents. The blood lead concentration was in average significantly higher in the Portoscuso group compared to controls. The linear model applied to the total population studied (n 64) showed that the blood lead concentration was inversely and significantly associated with IQ, with an extrapolated decline of 1.29 points in total IQ for each microgram/dl increase of blood concentration. According to the recent scientific literature on this topic, results of our pilot study suggest the need to further lower the definition of an elevated blood lead concentration for children to a threshold significantly below 10 micrograms/dl, value till now considered "safe" for the children's CNS.
为评估极低剂量无机铅暴露对中枢神经系统（CNS）的潜在早期不良影响，我们测量了当前血铅浓度（PhB）普遍低于10微克/分升的青少年的智商（IQ）。我们分析了居住在距铅冶炼厂2公里的小镇波尔托斯库索的32名撒丁岛青少年以及居住在距同一冶炼厂约15公里的圣安蒂奥科镇的其他32名对照者的血铅浓度和个体智商。使用了韦氏儿童智力量表修订版（WISC - R）进行测试。通过线性多变量模型估计智商与血铅浓度之间的关系，并对几个潜在的混杂因素进行了调整，如父母的教育和社会经济水平。与对照组相比，波尔托斯库索组的血铅浓度平均显著更高。应用于整个研究人群（n = 64）的线性模型表明，血铅浓度与智商呈显著负相关，血铅浓度每增加1微克/分升，总智商预计下降1.29分。根据近期关于该主题的科学文献，我们的初步研究结果表明，有必要将儿童血铅浓度升高的定义进一步降低至显著低于10微克/分升的阈值，该值迄今一直被认为对儿童中枢神经系统是“安全的”。
