Guérin O, Carré N, Garnier R
Cellule inter-régionale d'épidémiologie d'Ile-de-France, institut de veille sanitaire, Paris, France.
Rev Epidemiol Sante Publique. 2010 Jun;58(3):181-7. doi: 10.1016/j.respe.2010.03.001. Epub 2010 Apr 28.
Given the serious health effects of lead poisoning (Pb> or =10microg/dL), the present study was designed to estimate the time required to reach and identify factors associated with reaching Pb<10microg/dL according to the severity of the poisoning.
Since 1992, the Greater Paris lead poisoning monitoring system (SSSILF) has been systematically recording data on blood lead levels of screening and follow-up testing of children in the region. In children under the age of seven when screened positive for lead poisoning, survival curves without reaching the threshold of 10microg/dL and the relative risk (RR) of reaching this threshold were calculated (Kaplan-Meier curves and Cox model), according to blood lead level groups (Group 4: Pb> or =45microg/dL; Group 3: 25microg/dL< or =Pb<45microg/dL; Group 2: 10microg/dL< or =Pb<25microg/dL; (by definition, Group 1: Pb<100microg/L and risk factors of poisoning).
The median survival times without reaching the threshold of Pb<10microg/dL were 72.7 months for Group 4, 36.8 months for Group 3 and 14.5 months for Group 2. Compared to reference categories, the time to Pb<10microg/dL was longer for children aged four and over at the time they screened positive for poisoning (Groups 4 and 3), for children displaying pica behavior (Groups 3 and 2), for children in an environment with another child suffering from lead poisoning (Groups 3 and 2) and for children of mothers from Sub-Saharan or North Africa countries (Group 2); the differences reached statistical significance. Changes in Pb levels were better for all children (Groups 4, 3 and 2) screened over the most recent period, i.e. 2002 to 2006, and for Group 2 children living in Paris or the nearby district of Seine-Saint-Denis.
While the time required has gone down over recent years, the time to reach the threshold of Pb<10microg/dL is counted in years and varies depending on known poisoning risk factors and the district responsible for patient management. It is essential to have early lead poisoning screening for children in high-risk groups and then follow-up after rapid implementation of appropriate medical and social measures.
鉴于铅中毒（血铅水平≥10μg/dL）对健康有严重影响，本研究旨在根据中毒严重程度估算达到血铅水平<10μg/dL所需的时间，并确定与之相关的因素。
自1992年以来，大巴黎铅中毒监测系统（SSSILF）一直在系统记录该地区儿童筛查和随访检测的血铅水平数据。对于筛查出铅中毒阳性的7岁以下儿童，根据血铅水平分组（第4组：血铅水平≥45μg/dL；第3组：25μg/dL≤血铅水平<45μg/dL；第2组：10μg/dL≤血铅水平<25μg/dL；（根据定义，第1组：血铅水平<10μg/L且有中毒风险因素），计算未达到10μg/dL阈值的生存曲线以及达到该阈值的相对风险（RR）（Kaplan-Meier曲线和Cox模型）。
第4组未达到血铅水平<10μg/dL阈值的中位生存时间为72.7个月，第3组为36.8个月，第2组为14.5个月。与参考类别相比，中毒筛查呈阳性时年龄在4岁及以上的儿童（第4组和第3组）、有异食癖行为的儿童（第3组和第2组）、所处环境中有另一名铅中毒儿童的儿童（第3组和第2组）以及母亲来自撒哈拉以南或北非国家的儿童（第2组），达到血铅水平<10μg/dL的时间更长；差异具有统计学意义。在最近时期（即2002年至2006年）筛查的所有儿童（第4组、第3组和第2组）以及居住在巴黎或塞纳 - 圣但尼附近地区的第2组儿童，血铅水平变化情况更好。
虽然近年来所需时间有所下降，但达到血铅水平<10μg/dL的时间仍以年计，且因已知的中毒风险因素以及负责患者管理的地区而异。对高危组儿童进行早期铅中毒筛查，并在迅速实施适当的医疗和社会措施后进行随访至关重要。
