北京市儿童血铅水平及相关因素的调查研究

目的为了解北京市儿童血铅水平及相关因素。方法对本市９所幼儿园２４６名１～６岁儿童进行静脉血铅测定并做危险因素问卷调查，同时测定部分幼儿园的水、空气、食品、灰尘、玩具、幼儿手上灰尘中铅含量。结果本次调查儿童血铅≥１００μｇ／Ｌ者占６８．７％，（１μｇ／Ｌ＝０．００４８３μｍｏｌ／Ｌ），矿区儿童血铅水平显著高于近效区，Ｐ＜０．０１。结论儿童高血铅与空气中铅含量及某些生活行为有密切关系。     

808例学龄前儿童血铅水平与相关因素分析

目的 了解兰州市学龄前儿童血铅水平及影响因素。方法 采用分层整群抽样法对兰州市９所幼儿园的８０８名７～７ａ儿童进行毛细血管血铅测定，室内外尘土及环境铅测定，对儿童家庭和环境等因素进行问卷调查。结果 儿童血铅平均值为１０１．５８μｇ／Ｌ，标准差为４８．７５μｇ／Ｌ，其中３９．１％≥１００μｇ／Ｌ，工业区儿童血铅最高，其次是市中心区，环境铅与血铅呈明显的正相关（ｒ＝１８．１３ Ｐ〈０．０００１）。住在     

补钙对中度铅中毒儿童的治疗效果：随机双盲临床对照研究

目的探讨补充钙质对中度铅中毒患儿的治疗效果和安全性。方法将符合入选标准、血铅水平在２００～４４９μｇ／Ｌ（１μｇ／Ｌ＝０．００４８３μｍｏｌ／Ｌ）的中度铅中毒患儿随机双盲方法分为实验组和对照组各３０例。结果无论是服钙剂组（实验组）的患儿还是服安慰剂组（对照组）的患儿，经过３个月的治疗，血铅水平均有明显下降。钙剂治疗组在治疗的３个月中血铅下降的幅度达７５μｇ／Ｌ，幅度远大于安慰剂组（３５μｇ／Ｌ），差异有极显著意义（Ｐ＜０．０１）。在治疗过程中，两组患儿均未出现肝肾功能异常，未出现高尿钙症及其他不良反应。结论补充钙剂对中度铅中毒患儿是有效和安全的方法。     

新生儿血铅水平与环境因素的相关性研究

目的 了解本地新生儿因铅水平现状及其相关的影响因素。方法 采用石墨炉原子吸收光谱法。于１９９８年３～６月，对在我院产科出生的１０３例新生儿进行耳垂微量血血铅含量的测定，并对小儿出生情况及产妇、家庭环境等相关因素进行问卷调查。结果 （１）在１０３例新生儿中，血铅最高值１９７μｇ／Ｌ，最你值２７μｇ／Ｌ，几何均值为７１μｇ／Ｌ，≥１００μｇ／Ｌ者２５例，占２４．３％；（２）早产伴低体重（６例）及窒息史     

低浓度铅负荷妊娠母鼠及仔鼠体内铅的动态观察

铅对儿童中枢神经系统的影响是当今的热门课题。血铅浓度１００μｇ／Ｌ（１μｇ／Ｌ＝０．００４８３μｍｏｌ／Ｌ）作为儿童铅中毒诊断标准已广为接受。研究妊娠期铅在母胎体内的动力学过程是评价宫内（胎儿期）铅暴露远期危害的基础，因而，作者观察与比较了低浓度铅和...     

低水平铅暴露对早期婴儿发育的影响

为了研究出生前后低水平铅暴露对儿童发育的影响，前瞻性观察了１０２例出生时血铅在０．１０～０．８４μｍｏｌ／Ｌ低水平铅暴露婴儿的发育，通过多因素统计评价其因果关系。结果发现，即使在这个以往完全被认为是正常的铅暴露范围内，脐血血铅水平与３个月时在Ｂａｙｌｅｙ发育量表上的精神发育指数（ＭＤＩ）和心理运动发育指数（ＰＤＩ）有明确的负相关关系。血铅≥０．４８μｍｏｌ／Ｌ的婴儿在３月龄时的ＭＤＩ和ＰＤＩ明显低于血铅水平＜０．４８μｍｏｌ／Ｌ者，分别相差４．６和８．８分，差异有非常显著意义（Ｐ＜０．０１）。经多元逐步回归分析和多元协方差分析，结果提示这种差异依然存在。提示儿童血铅水平≥０．４８μｍｏｌ／Ｌ时确能对其早期发育产生不利影响。其前瞻性的变化规律正在进一步观察之中     

血清铋浓度的测定及口服胶体次枸橼酸铋停药前后患儿血清铋的浓度

目的　探讨各年龄组儿童正常血清铋浓度及服用治疗剂量胶体次枸橼酸铋（ＣＢＳ）的安全性。方法　用原子荧光光谱法测定９７ 例１～１２ 岁正常儿童血清铋浓度和９４ 例５ ～１２ 岁经胃镜检查确诊为幽门螺杆菌（Ｈｐ）相关性胃十二指肠疾病的儿童,服ＣＢＳ６ 周,合并阿莫仙和甲硝唑各服２ 周的治疗方案后,进行服ＣＢＳ后１、２、４、６ 周和停服后１ 周、１～２ 个月、３～４ 个月、５～６ 个月和６ ～１２ 个月以上血清铋浓度的观察。结果　（１）正常儿童血清铋浓度在各组间经统计,Ｆ＝ １３．７５,Ｐ＝０．０００ １,差异有非常显著意义。本组正常儿童血铋浓度从１ 岁始随年龄增长而增高,５～６ 岁组到１２ 岁保持相对恒定。（２）服ＣＢＳ后各组血清铋浓度经统计,Ｆ＝３７．１８,Ｐ＝０．０００ １,其中４ 周、６ 周两组与１ 周、２ 周两组间差异有显著意义（ Ｐ＜ ０．０５）,服药后血铋浓度逐渐上升,４ 周后不再继续升高,平均在（１０．２ ±２．４）μｇ／Ｌ或（１０．８±２．１） μｇ／Ｌ,远未达到临界浓度（５０～１００ μｇ／Ｌ）。（３）停药后各组血铋浓度经统计,Ｆ＝２２．１１,Ｐ＜０．０００ １,各组均数间两两比较差异也有显著意义（ Ｐ＜ ０．０５）,可见服Ｃ     

新生儿骨碱性磷酸酶活性增高与其血铅水平的相关性研究

为研究新生儿骨碱性磷酸酶（ＢＡＬＰ）活性与其血铅水平的相关关系,于１９９７年１１月～１９９８年１１月对我院产科出生的５８５例新生儿,采用全血干化学免疫浓缩法,取耳垂微量血３０μｌ进行ＢＡＬＰ活性测定,同时,对测得ＢＡＬＰ〉２００Ｕ／Ｌ的２１５例新生儿随机抽取１００例,用石墨炉原子吸收光谱法进一步测定血铅含量。结果：①５８５例新生儿中,ＢＡＬＰ活性≤２００Ｕ／Ｌ（正常）３７０例,～２５０Ｕ／Ｌ（临界佝偻病）１６７例,～３００Ｕ／Ｌ（佝偻病活动期）４８例,阳性检出率３６．７５％;②所测血铅的１００例中,其血铅含量最高值１９７μｇ／Ｌ,最低值２７．４０μｇ／Ｌ,均值７６．９２μｇ／Ｌ,≥１００μｇ／Ｌ２１例（占２１％）;③ＢＡＬＰ为２０１Ｕ～２５０Ｕ／Ｌ的１６７例中,血铅≥１００μｇ／Ｌ者８例,ＢＡＬＰ２５１Ｕ／Ｌ～     

铅中毒的不常见来源

铅中毒是当今儿童最常见的受环境危害的疾病。血清中铅浓度达到０．４８３ｕｍｏｌ／Ｌ（１０ｕｇ／ｄｌ），即可引起儿童中毒。即使采取各种防护措施，全国仍有大约４．４％儿童的血铅含量增加。旧房子的含铅涂料、室内尘屑是儿童铅中毒的重要原因。有时无明显铅接触史者亦可发生中毒，故应强调彻底的环境检查的重要性，以及保健医生、卫生保健人员在查找铅源方面保持不懈警惕性的重要性。病例女孩，６岁。体检发现外周血铅含量为１．４９ｕｍｏｌ／Ｌ（３１ｕｌ／ｄｌ），静脉铅含量为１．６４ｕｍｏｌ／Ｌ（３４ｕｇ／ｄｌ），无异常行为…     

儿童保健医学进展

现对１９９８年我国儿科科技期刊有关儿保及儿童精神、心理、行为、发育障碍等方面的报道，简述如下。１儿童铅中毒目前国际公认的儿童铅中毒诊断标准为血铅≥１００μｇ／Ｌ［１］。大量的研究显示，在此水平以上时即能对儿童的智能发育产生不可逆的损害。据近１０年来国...     

Portable lead analyzer to locate source of lead

Objective :To investigate the sources of lead in the environment in children with elevated blood, with the help of a Field Portable X-Ray Fluorescence Analyzer.Methods : One hundred and seven school children were chosen for this study on a random basis, from Mangalore and Karnataka. Their blood lead was analyzed. Of the cases analyzed, 10 students whose blood lead level was more than 40 μg/dl were investigated using a field portable X-Ray Fluorescence Analyzer. This is the first time such a device has been available for this purpose in India.Results: The ‘likely’ source of lead exposure could be determined in eight cases which was from the immediate environment of the children like ‘lead-based’ paint on surfaces in the house, on playground and other exterior equipment; lead storage batteries, contaminated dust and soil and other lead-containing substances.Conclusion: The use of an X-Ray Fluorescence Analyser appeared to be useful in determining the source of lead     

Blood lead,ethnic origin,and lead exposure.

A survey of blood lead concentrations is reported in a group of 199 young Walsall children (3-6 years of age). The geometric mean blood lead concentration was 0.47 mumol/l (range 0.2-1.6 mumol/l). There were no significant differences in blood lead concentrations between groups of children with different ages, sex, ethnic origin, or environment.     

Blood lead screening

To evaluate local procedures for and barriers to testing Medicaid patients for lead toxicity, a retrospective review of 675 charts of Medicaid patients' age 12 to 36 months form the 7 practices who serve the vast majority of Medicaid children in Kalamazoo, Michigan was undertaken. We identified and tested a model for barriers to patients and physicians obtaining blood lead levels. Only 27.6% had blood lead levels substantially lower than the universal testing mandated by the Centers for Medicare and Medicaid Services. Physicians overestimated the number of children having blood lead tests, even with adjusting for patient non-compliance. Practices varied sharply in their approach to screening. Of 489 patients without findable lead test results, 139 (28.4%) were attributable to previous screening, 98 (20.0%) to patient failure, 181 (37.0%) to physician failure, 52 (10.6%) to patient + physician failure and 19 (3.9%) were indeterminate. There is need for improvement, standardization and unification of lead screening guidelines. Understanding barriers to blood lead testing is also necessary to develop credible data to promote shifts in public policy regarding lead abatement. Further studies should be done, such as interviews and questionnaires to determine why physicians fail to order blood lead tests, and patients fail to appear for a test that has been ordered.     

Childhood lead poisoning

Although the average blood lead levels of Americans have markedly declined, a significant number of children remain at risk. This article discusses the mechanisms of lead poisoning and the screening of children for lead poisoning, and the treatment of symptomatic and asymptomatic children.     

Need for the lead mobilization test in children with lead poisoning

We evaluated the recommendation of the Centers for Disease Control, that children with moderate lead poisoning undergo the lead mobilization test (LMT) to determine the need for a full course of chelation treatment. Current criteria for selection for this test include a blood Pb concentration (bPb) between 25 and 55 micrograms/dl and an erythrocyte protoporphyrin level greater than 35 micrograms/dl. To determine whether the eligibility criteria could be refined to a smaller group of patients, we compared bPb determinations obtained on the day of the LMT in 198 children with moderate Pb poisoning to the results of the LMT. We found that children with bPb less than 25 micrograms/dl were unlikely to respond to the test dose of calcium disodium ethylenediamine tetraacetate with a Pb diuresis (24/25 patients had low urinary Pb excretion on the LMT). In contrast, 88% of children with bPb greater than or equal to 40 micrograms/dl were likely to excrete sufficient Pb to indicate the need for a full course of chelation. We conclude that the LMT is indicated for children with bPbs between 25 and 40 micrograms/dl. Children with bPb between 40 and 55 micrograms/dl may receive chelation therapy without having an LMT, if the performance of the LMT is not practical. Patients with levels less than 25 micrograms/dl should be followed clinically and removed from further Pb exposure.     

Effects of iron deficiency on lead excretion in children with moderate lead intoxication

The effect of iron status on calcium disodium edetate (CaNa2EDTA)-induced lead diuresis was examined in 112 children with moderate lead intoxication. Patients whose blood lead levels were between 25 and 55 micrograms/dl and who had erythrocyte protoporphyrin concentrations greater than or equal to 35 micrograms/dl underwent provocative testing to determine the need for a full course of chelation therapy. A blood sample for lead, erythrocyte protoporphyrin, and serum ferritin determinations was obtained immediately before the intramuscular administration of CaNa2EDTA, 500 mg/m2. Determination of urinary lead level was based on an 8-hour urine collection. Blood lead and ferritin levels were significantly correlated with urinary lead excretion: r = 0.542 and 0.298, respectively, p less than 0.01 for both. Multiple regression models were tested to assess the independent effects of the variables. With blood lead level controlled, ferritin remained significantly associated with urinary lead excretion; for every 1 ng/ml increase in ferritin, urinary lead increased by 2.4 micrograms. This small effect of ferritin on urinary lead was illustrated in a discriminant analysis. Using blood lead level by itself as the independent variable resulted in a 76% correct assignment of provocative test outcomes. Knowing the ferritin level improved this assignment accuracy by only 3%. We conclude that the iron status, as measured by serum ferritin, of children with moderate lead intoxication, has a small but significant effect on CaNa2EDTA-induced lead diuresis. This effect may influence the interpretation of borderline provocative test outcomes. Although chelation therapy should not be withheld pending treatment of iron deficiency, lead stores should be reassessed after iron repletion.