学龄前儿童血铅水平与5种微量元素相互关系的研究

目的　探讨学龄前儿童铅中毒现状及血铅水平与微量元素锌、铁、铜、钙、锰间的相互关系。方法　采用电感耦合高频等离子体原子发射光谱法 ,广东省佛山市妇幼保健院于 2 0 0 3年对 5 175名 3～ 6岁学龄前儿童进行血铅、锌、铁、铜、钙、锰含量的测定及血铅与其他 5种微量元素的相关分析。结果　 (1) 5 175名儿童中 ,血铅含量最低值为 0 0 2 4mg/L ,最高值为 0 2 9mg/L ,几何均值为 0 10 1mg/L ,铅中毒发生率为 4 3 7%。 (2 )线性回归分析显示血锌、铜标准回归系数最大 ,分别为 0 0 5 1和 0 0 4 1,与儿童血铅水平差异有显著性 (P <0 0 1)。 (3)双因素方差分析显示血铅与血锌、血铜呈负相关关系。结论　儿童铅中毒可导致血锌、血铜水平下降。     

铅中毒儿童血清锌、铜、铁、钙等元素含量变化

目的探讨铅中毒儿童体内锌、铜、铁、钙等元素含量变化。方法采用分层随机抽样方法进行抽样。在市区、农村、海岛共抽取540名儿童。对这些儿童进行血铅及其他元素(锌、铜、铁、钙等)含量测定,并分析这些元素含量在儿童铅中毒情况下有无变化。结果铅中毒组血锌水平(4.93±1.12)mg/L,明显低于非铅中毒组(t=2.282 P<0.05),其他元素含量两组无差异。多元逐步回归分析结果显示儿童体内血锌、血铜含量对儿童血铅水平有显著意义。结论补充适量锌制剂或通过膳食补锌可预防儿童铅中毒,减少铅对机体的毒性作用。     

补充铁、锌对反复呼吸道感染患儿血清其它微量元素的影响

等离子体原子发射直读光谱法（ＤＣＰ－ＡＥＳ）检测８４例反复呼吸道感染（ＲＲＩ）患儿血清锌、锰、铝、镉、铁、铅、铜、镍、钛、钴、锂和铬的水平，并对其中密切合作的３７例血锌和／或铁水平降低者进行了补充富马酸亚铁和／或硫酸锌治疗后的纵向观察。结果表明治疗前ＲＲＩ组血清锌、铁、铅、镍、钛、钴、锂均值显著降低，锰、铝、镉、铜、铬均值无明显变化；治疗２个月后，ＲＲＩ患儿随临床症状明显改善，血清锌、铁、钛、钴、锂水平较前明显升高，铝、镉、铜水平下降，锰、镍、铅水平则无显著变化。提示铁、锌缺乏可能在ＲＲＩ发病中占有重要地位，补充铁锌对其它元素的血清水平及分布等可能有明显影响。     

新生儿换血治疗的血源性铅暴露

目的探讨新生儿换血治疗中使用血库血的铅暴露危险性。方法2006年6～12月对本院新生儿科37例因高胆红素血症进行换血治疗的新生儿进行换血前后血铅水平监测，并对换血使用的53份血库血进行血铅检测。血铅测定采用石墨炉原子吸收光谱法。结果53份血库血平均血铅水平为101．02μg／L，已处于铅中毒水平；而高血铅（≥100μg／L）的血库血占28．5％（15／53份），其中3份血库血样本血铅量≥200μg／L，达Ⅲ级铅中毒水平。高胆红素血症患儿换血后血铅值≥100μg／L的百分率由2．9％升高到19．0％，换血后平均血铅水平明显高于换血前（P〈0．01），血铅水平平均增加26．62μg／L，最高1例增加81．0μg／L。结论血库血铅污染明显，新生儿换血的血源存在血源性铅暴露的危险，应在采血前进行铅筛检，避免新生儿血源性铅中毒。     

二巯基丁二酸治疗儿童铅中毒的研究进展

二巯基丁二酸（DMSA）作为口服驱铅药物在国外已广泛用于临床。由于依地酸二钠钙（CaNa2-EDTA）需静脉滴注给药,有一定的肾毒性,且治疗过程中同时增加了尿中锌、铜、钙等元素的排出。而DMSA口服给药驱铅效果优于CaNa2-EDTA,尤其对脑等软组织中的铅有较强的清除能力,可改善铅毒性所致血液生化指标的异常,治疗过程中不良反应少,且相对选择性驱铅对其他元素的干扰较小,因此DMSA已作为儿童驱铅治疗的首选药物。目前DMSA是否推荐用于治疗血铅水平≤450μg／L的患儿成为国外研究的热点。我国卫生部2006年2月颁发的《儿童高铅血症和铅中毒分级和处理原则（试行）》指出,儿童血铅水平在采用静脉血复测后仍然高于或等于250μg／L,且驱铅试验阳性者需进行药物驱铅治疗,首选药物为DMSA。该文综述了近年来DMSA治疗儿童铅中毒的临床及动物实验方面的一些研究进展。     

湖南省城镇学龄前儿童血铅水平流行病学调查

目的：调查湖南省城镇学龄前儿童血铅水平及影响因素,为儿童铅中毒的防治提供科学依据。方法：2008年9月至2009年6月整群随机抽取湖南省12个地区城镇学龄前儿童2 044名,男1 108名,女936名,年龄2～6岁,平均4.4±1.1岁。采用原子吸收光谱法测定末梢血血铅水平, 并采用《中国部分城市儿童铅中毒防治项目调查表》进行问卷调查。Logistic回归分析血铅水平的影响因素。结果：湖南省学龄前儿童平均血铅值为81.9±34.5 μg/L。血铅水平≥100 μg/L者482例,占23.58%。其中血铅水平100～199 μg/L(高铅血症)472例,占23.09%,血铅水平≥200 μg/L（铅中毒）10例,占0.49%。不同年龄组间血铅异常(血铅水平≥100 μg/L)率差异有统计学意义(P<0.01)。男童的血铅异常率为28.99%,高于女童的 21.98% （P<0.01）。不同地区儿童血铅异常率差异亦有统计学意义 (P<0.01)。回归分析显示,男性(OR=1.449, P<0.01)、父亲从事铅暴露职业(OR=1.314, P<0.01)及母亲常用染发剂（OR=1.678,P<0.05）为儿童血铅异常的危险因素。结论：湖南省城镇学龄前儿童血铅异常率较高。该省城镇学龄前儿童血铅异常率与儿童所在地区和年龄有关。男性、父亲从事铅暴露职业及母亲常用染发剂为儿童血铅异常的危险因素。［中国当代儿科杂志,2010,12（8）：645-649］     

甘肃省金昌市儿童血铅水平调查分析

目的了解甘肃省金昌市2~7岁儿童血铅水平。方法随机抽取2004年10月~2005年6月金昌市部分幼儿园256名儿童。男133名,女123名;用石墨炉原子吸收分光光度仪测定血铅水平。结果儿童血铅水平为(126.30±52.98)μg/L。血铅水平最低值为28.3μg/L,最高值为268.0μg/L,超过100μg/L者160例,占62.54%。血铅水平随年龄增加有上升趋势,2~3岁组明显低于5~6岁组、6~7岁组,差异有统计学意义(P<0.05,0.01);性别间血铅水平差异无统计学意义(P>0.05)。结论甘肃金昌市儿童血铅水平较高,铅中毒现象不容忽视。     

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     

佝偻病患儿血清微量元素水平测定及相关分析

目的：人体内某些微量元素与儿童佝偻病的发病密切相关,该文探讨佝偻病患儿体内微量元素(钙、锌、铜、镁、铅)变化及其水平与佝偻病的相互关系。方法：选择46例佝偻病患儿和68例正常儿童采用火焰原子吸收法测定血清钙(Ca)、锌(Zn)、铜(Cu)和镁(Mg),采用石墨炉原子吸收法测定血清铅(Pb)。结果：佝偻病患儿血钙和血锌水平低于正常对照组,血铜和血铅高于正常对照组,差异均有显著性意义;血镁稍高于正常对照组,但两组之间差异无显著性。相关分析显示,佝偻病与血钙和血锌水平呈负相关(r=-0.538,P<0.01;r=-0.316,P<0.05),与血铅水平呈正相关(r=0.253,P<0.05),佝偻病患儿血钙与血锌呈正相关(r=0.523,P<0.01),与血镁、血铅呈负相关(r=-0.231,P<0.05;r=-0.367,P<0.05)。结论：该组检测结果提示低锌和高铅可能参与了佝偻病的发病及骨骼改变;对于佝偻病正规治疗效果不显著者,应注意检查血锌和血铅水平。     

铅污染区儿童血铅与锌原卟啉、红细胞参数相关性研究

目的 探讨铅污染区儿童血铅与锌原卟啉、红细胞参数相关性。方法 对云南某县铅锌矿区和县城非铅锌矿区2～9岁儿童共464人进行血铅（BPb）水平、红细胞参数及锌原卟啉（ZPP）水平调查，按血铅水平分为高、低血铅组并进行血Pb与红细胞参数（RBC、HB、HCT、MCV、MCH、MCHC、RDW）及ZPP相关性分析。结果儿童血铅浓度均值154．4ug／L，铅中毒率79．1％，ZPP均值2．7ug／gHb。血铅〉250ug／L时，血铅与红细胞参数具有相关性（RR：0．637）。高铅组血铅水平与RBC、ZPP有较强相关性（r分别为：-0．975、0．957）。RBC随血铅水平增高呈高度负相关，血铅水平〈200ug／L时，与zPP无相关性。血铅水平达～250ug／L、～300u∥L、～350ug／L时，血铅与ZPP具有较强相关性（r分别为：0．567、0．93、0．886）并呈高度正相关。结论随血铅水平的增高，RBC与血铅呈高度负相关，当血铅水平〉250ug／L时，血铅与ZPP具有高度正相关性，而当血铅水平〈200ug／L时，与ZPP相关关系不密切，因此ZPP不能作为铅中毒筛查指标。     

青岛市婴幼儿佝偻病312例血微量营养素分析

目的探讨微量营养素与维生素D(VitD)缺乏性佝偻病的相关性。方法选择佝偻病患儿312例和健康儿童297例,采用原子吸收光谱法测定血钙、镁及锌、铁、铜、铅和铬水平。结果佝偻病患儿血钙、锌、铁水平降低,而铅、镁升高,组间差异具有非常著性意义(P均<0.01);相关性分析,佝偻病与钙、锌、铁呈负相关;与血铅、镁呈正相关(P均<0.01)。佝偻病血微量营养素间相关性分析,钙与锌、铁,锌与铁呈正相关,铅与钙、锌、铁,镁与铁呈明显负相关。佝偻病铅中毒发生率为8.01%。结论血钙、锌、铁降低及铅、镁升高与佝偻病密切相关。补充锌、铁制剂及高铅干预治疗是佝偻病防治的措施之一。     

抽动障碍患儿432例血铅水平对脑电图活动的影响

目的 探讨抽动障碍患儿血铅水平变化对脑电活动的影响及其发病机制的研究,对比不同血铅水平患儿脑电图变化的特点.方法 对本院2005年1月- 2011年4月临床确诊的432例抽动障碍患儿进行血铅水平及脑电图检测.采用原子吸收光谱分析法测定其血铅水平,并进行t检验.将432例抽动障碍患儿分为3组,Ⅰ组:血铅水平＜50μg·L-1;Ⅱ组:血铅水平50 ～ 100μg·L-1;Ⅲ组:血铅水平＞ 100 μg·L-1.结果 1.Ⅰ组患儿脑电图异常发生率为7.14％(2/28例),Ⅱ组患儿脑电图异常发生率为14.23％(40/281例),Ⅲ组患儿脑电图异常发生率为46.34％(57/123例).Ⅰ组与Ⅱ组脑电图异常发生率比较差异无统计学意义(P＞0.05),Ⅰ组与Ⅲ组脑电图异常发生率比较差异有统计学意义(P＜0.01),Ⅱ组与Ⅲ组脑电图异常发生率比较差异有统计学意义(P＜0.01).2.除年龄≤4岁患儿外,脑电图异常患儿较脑电图正常患儿血铅水平明显升高(P＜0.01,0.05).结论 血铅水平升高会加重抽动障碍患儿的脑功能损伤.及早进行驱铅治疗可能对抽动障碍患儿脑功能损伤的恢复有重要意义.     

Amniotic fluid levels of selected trace elements and heavy metals in pregnancies complicated with neural tube defects

The aims of this study were to determine the levels of trace elements and heavy metals, namely aluminum (Al), chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), molybdenum (Mo), cadmium (Cd), tin (Sn), antimony (Sb), mercury (Hg), and lead (Pb), in the amniotic fluid of pregnant women, and to investigate their relationship with neural tube defects (NTDs). The study included 36 pregnant women whose fetuses were complicated with NTDs (study group) and 39 pregnant women with unaffected healthy fetuses (control group), who were matched for body mass index and gestational weeks. The amniotic fluid levels of trace elements and heavy metals were measured using inductively coupled plasma-mass spectrometry and compared between the two groups. Significantly lower mean levels of Zn and Mo and significantly higher levels of Al, Sn, Sb, and Hg in the study group than in the healthy control group were observed, which implied that these elements are possibly correlated with risk factors for the occurrence of NTDs. In contrast, there were no significant differences in the levels of Cr, Mn, Co, Ni, Cu, As, Cd, and Pb between the groups (P ≥ .05).     

Serum trace elements in children receiving long-term parenteral nutrition

The trace elements iron (Fe), copper (Cu), zinc (Zn), selenium (Se), chromium (Cr), manganese (Mn), nickel (Ni), rubidium (Rb), and bromine (Br) were determined in serum from 18 children, ages 4 to 65 months, who received long-term total parenteral nutrition (TPN). Nine patients (group 1) received TPN as their only source of nutrition; the other nine (group 2) ingested 30% to 70% of their total calorie requirement and received the remainder intravenously. The reference group consisted of 19 healthy children of similar age and sex distribution. Groups 1 and 2 had received parenteral nutrition for 28.4 +/- 13.7 (SD) and 23.1 +/- 17.1 (SD) months, respectively. All patients in group 1 and four in group 2 had short bowel syndrome; four in group 2 had pseudo-obstruction syndrome. Patients in group 1 had normal serum levels of Fe, Cu, and Mn, but increased levels of Zn; they had decreased serum concentrations of Se, Cr, Ni, Rb, and Br. Patients in group 2 had decreased serum levels of Mn, Cr, Ni, Rb, and Br. Those trace elements not supplemented in TPN solutions (Se, Cr, Mn, Ni, Rb, and Br) were lower in the children receiving TPN than in the control children, indicating inadequate intake of these trace elements from food and TPN solutions. However, no obvious clinical signs or symptoms of trace element deficiencies were observed.     

Erythrocyte protoporphyrin and blood lead levels of children from Jammu and Srinagar and papier mache trainees

In order to examine the prevalence of iron deficiency and environmental lead absorption in children, erythrocyte protoporphyrin (EP) and blood lead (B-Pb) levels were measured in a group of 112 children from Jammu and Srinagar. The mean EP levels were 50 and 59 μg/dl and mean B-Pb were 15 and 8 μg/dl respectively. Similarly, the mean B-Pb and EP levels of papier mache trainees/workers were 23/25 and 96/98 μg/dl respectively. These results suggest higher incidence of iron deficiency in Srinagar children compared with those in Jammu. However, the mean B-Pb level of Jammu children was twice those in Srinagar. While this follow-up study on papier mache trainees/workers shows significant improvement in B-Pb since 1981, these levels are close to the currently recognized cut-off levels for children. Moreover, the continued underlying iron deficiency predisposes these young female trainees/workers to enhanced lead absorption, thus regular monitoring of both EP and B-Pb is recommended.     

Confirmation and extension of association of blood lead with attention-deficit/hyperactivity disorder (ADHD) and ADHD symptom domains at population-typical exposure levels

Background:  Recent studies have suggested that child attention-deficit/hyperactivity disorder (ADHD) and its symptom domains are related to blood lead level, even at background exposure levels typical in western countries. However, recent studies disagreed as to whether lead was related to inattention or hyperactivity-impulsivity within the ADHD domain. More definitive evaluation of these questions was sought.
Methods:  Two hundred and thirty-six (236) children aged 6–17 years participated (61 ADHD-Combined type, 47 ADHD Predominantly Inattentive type, 99 non-ADHD control, 29 unclassified borderline, situational, or not otherwise specified (NOS) cases). Formal diagnosis was reliably established by a best estimate procedure based on a semi-structured clinical interview and parent and teacher ratings. Lead was assayed from whole blood using inductively coupled plasma mass spectrometry with a method detection limit of .3 μg/dL.
Results:  Blood lead levels were slightly below United States and Western Europe population exposure averages, with a mean of .73 and a maximum of 2.2 μg/dL. This is the lowest level of blood lead ever studied in relation to ADHD. After statistical control for covariates including IQ and prenatal smoking exposure, blood lead was associated with ADHD-combined type but not inattentive type. Parent and teacher report indicated association of blood lead with Conners cognitive problems, but only teacher report showed effects on DSM-IV inattention symptoms. Blood lead was associated with hyperactivity-impulsivity in parent report regardless of measurement method, whereas teacher report effects depended on child treatment history.
Conclusions:  These findings confirm that in children with typical US population lead exposure, careful identification of children with ADHD also identifies children with slightly elevated blood lead.     

Lead and Growth

Lead is highly toxic to the human body and children are much more vulnerable to lead toxicity than adults. Many studies have revealed that relatively low levels of blood lead can adversely affect human health, especially childhood growth and development. Blood lead levels (BLL) of children and adults have been decreasing recently almost all over the world, but a safety level for blood lead does not exist, and lead exposure is still a serious health problem especially for fetuses and children. Maternal lead burden causes fetal lead exposure and increases the risk of abortions, prematurity, low birth weight, and some minor anomalies. Infant BLL are inversely associated with weight gain. A negative relationship between somatic growth and BLL in children has been revealed. It has been suggested that lead exposure causes decrease of gonadotropin secretion of adolescents and delay of pubertal development. Several studies have revealed that children who are exposed to cigarette smoke have higher BLL than children who are not. Children should be protected from cigarette smoke for the purpose of avoiding the risk of increased BLL which might adversely affect their intellectual development and physical growth.     

Determination of heavy metal contents in human colostrum samples by electrothermal atomic absorption spectrophotometry

Determination of lead, cadmium, nickel, chromium, manganese and copper levels in colostrum samples (n = 30), collected from middle-class mothers, was carried out by electrothermal atomic absorption spectrophotometer (ETAAS) with Zeeman effect background correction using a tungsten-palladium-citric acid chemical modifier mixture. A wet-ashing procedure was applied to dissolve the samples and to remove the fat. The graphite furnace temperature programme for analytes determined by ETAAS was studied, and the optimum pyrolysis temperatures of Pb, Cd, Ni, Cr, Mn and Cu were determined in the presence of the modifier mixture. Detection limits of Pb, Cd, Cu, Mn and Cr were determined using a modifier mixture solution. Zinc and iron levels were determined by Zeeman flame atomic absorption spectrometer (F-AAS). Heavy metal levels (mean values) found in colostrum samples were 14.6 microg/l of Pb, 2.8 microg/l of Cd, 27.8 microg/l of Ni, 8.6 microg/l of Cr, 43.2 microg/l of Mn, 278 microg/l of Cu, 12.9 mg/l of Zn, and 3.5 mg/l of Fe. These metal levels were compared with results from other studies in different countries.     

Mineral composition of the milk of mothers of premature infants during early lactation

The authors have assessed the concentration of sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), zinc (Zn), copper (Cu), manganese (Mn), lithium (Li), cadmium (Cd) and lead (Pb) in the milk of mothers with premature births, during the first month of lactation. The levels of Na, Cu and Mn were decreased and those of K, Ca, Mg, Zn and Li were unchanged. The needs of Na, Ca and Mn for the premature infants are insufficient. Li, present in all the milk samples at a constant level, seems to be a common component. The incidence of Cd in the milk of 7 mothers and of Pb in 4 milk samples indicates their clearance from the mothers' organism.