兰州市婴幼儿血铅水平调查和相关因素分析

调查兰州市婴幼儿血铅水平和相关因素。取146名健康婴幼儿末梢血，采用石墨炉原子吸收光谱法，测得血铅浓度。被测婴幼儿的家长填写涉及45个因素的调查表。测得的血铅值和调查表内容进行多元逐步回归分析。结果，兰州市婴幼儿平均血铅水平为(80．4±39．4)μg/L，其中≥100μg／L35例，占23．9％。25月～30月龄组幼儿血铅水平最高，达(98．67±42．48)μg/L，较其它月龄组有显著差异。婴幼儿的血铅与年龄、胎龄有非常显著的相关性(P<0．01)l与父母的职业、使用油漆、现有体重等7个因素有显著的相关性(P<0．05)。     

儿童铅中毒高危因素分析

目的探讨儿童铅中毒发生的高危因素,以便能更好地进行预防。方法选择1055例门诊患儿。年龄5个月~16岁,平均(7.2±3.5)岁。应用3010-B血铅分析仪对患儿进行血铅测定;同时对每位患儿进行铅中毒影响因素问卷调查。结果儿童血铅水平(110.1±41.9)μg/L,铅中毒(血铅≥100μg/L)检出率为43.51%,各年龄组血铅水平无显著差异。多因素逐步回归分析显示,对儿童血铅水平发生显著影响因素依次是不勤洗手、经常吃膨化食品、偏(挑)食、不常补钙和锌及经常居室装修。结论不良的饮食和生活习惯是儿童铅中毒发生的高危因素。     

兰州某厂两所幼儿园儿童血铅水平及其影响因素

为了解兰州市某厂两所幼儿园 (简称一幼、二幼 )3岁～6岁儿童血铅含量及其相关影响因素 ,于1998年6月至1999年1月对两所幼儿园的学龄前儿童 ,采用石墨炉原子吸收光谱法取外周微量血0.1ml,测定198名儿童的血铅水平 ,并在专人指导下 ,由父母及老师填写 :“儿童健康及行为问卷” ,该问卷内容包括 :家庭一般状况、家庭社会环境 ,儿童个人生活习惯及行为能力等共计46项。结果 :二幼小儿血铅含量 (113.83±51.20) μg/L明显高于一幼 (86.64±19.36) μg/L ,经t检验 (t=4.352 ,P<0.001)。二幼儿童血铅升高与家庭环境、社会环境、个人卫生习惯等诸多因素有相关性。提示 :家长和老师的双方教育、个人的卫生习惯直接影响血铅水平。所以 ,健康教育是有效、可行的铅中毒干预手段。     

珠海市铅中毒儿童贫血发生率的调查

目的　了解珠海市铅中毒对儿童贫血发生率的影响。方法　根据 5 4 0名儿童血铅 (BPb)测定水平 ,将其分成非铅中毒组 (BPb <10 0 μg/L)和铅中毒组 (BPb≥ 10 0 μg/L) ,同时进行两组血细胞分析 ,测定红细胞 (RBC)、血红蛋白 (Hb)、红细胞平均容积 (MCV)、红细胞平均血红蛋白 (MCH)、红细胞平均血红蛋白浓度(MCHC)水平。结果　两组RBC、Hb、MCV、MCH、MCHC水平差异无显著性 (P均 >0 .0 5 )。结论　较低水平铅中毒患儿贫血发生率无显著升高。     

神经系统疾病儿童的血铅水平调查:单中心初步研究(英文)

目的儿童铅中毒具有很大的潜在危害。慢性低水平铅暴露会导致学习障碍及行为问题,如腹痛,失眠,多动,生长发育落后,听力损失,上肢无力。该研究旨在调查神经系统疾病儿童的血铅水平,并与健康儿童作比较。方法100名患有神经系统疾病的1～10岁儿童作为研究对象。100名年龄和性别匹配的健康儿童作为对照。采用火焰原子吸收光谱法检测血铅含量。结果神经系统疾病组儿童的平均血铅含量显著高于对照组,差异有显著性(113.2±47.5μg/Lvs84.7±38.0μg/L;P<0.01)。神经系统疾病组和对照组分别有44%和19%的儿童血铅超标(>100μg/L)。结论儿童血铅水平增高可能与神经系统疾病有关。建议对患神经系统疾病的儿童常规作血铅测定。     

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］     

季节变化对健康体检儿童血铅水平的影响

目的探讨季节变化对儿童血铅水平的影响。方法采用阳极溶出伏安法对健康查体儿童进行血铅检测,将入组儿童分婴幼儿组(1个月~3岁)、学龄前组(3~6岁)、学龄组(6~12岁)和青少年组(12~18岁),分析不同季节儿童血铅水平及铅中毒状况。结果共检测儿童13 233例。年龄1个月~18岁;男8315例,女4918例。平均血铅质量浓度60μg/L,第5和第95百分位数为19、138μg/L,儿童铅中毒检出率为14.8%,检出率随年龄增长而上升,以轻度铅中毒为主(χ2=116.3125 P<0.0001)。按照冬、春、秋、夏季顺序,血铅质量浓度分别为48、60、61、66μg/L;铅中毒检出率分别为9.5%、12.6%、15.5%、18.4%。夏、秋季节儿童铅质量浓度及铅中毒检出率有明显季节差异(χ2=128.0371 P<0.0001),多元Logistic回归结果分析显示男童、年龄越大越易发生铅中毒,秋、春、夏季发生铅中毒危险性较冬季大。结论儿童血铅水平与季节有关。北京地区秋季儿童铅中毒危险性最大。     

多发性抽动症患儿血铅水平测定的意义

目的研究多发性抽动症儿童血铅水平及铅接触的相关因素。方法对76例多发性抽动症患儿父母进行问卷调查铅接触相关因素,采用原子吸收光谱仪进行血铅测定。结果对多发性抽动症患儿76例进行血铅水平测定,结果36例血铅≥100μg/L,铅中毒发生率为47.37%(36/76),其中学龄前组铅中毒发生率为45.16%(14/31),学龄组为48.84%(22/45)。结论血铅增高与儿童多发性抽动症有一定关系,治疗多发性抽动症的同时应关注患儿血铅水平。     

神经系统疾病儿童的血铅水平调查：单中心初步研究

目的：儿童铅中毒具有很大的潜在危害。慢性低水平铅暴露会导致学习障碍及行为问题,如腹痛,失眠,多动,生长发育落后,听力损失,上肢无力。该研究旨在调查神经系统疾病儿童的血铅水平,并与健康儿童作比较。方法：100名患有神经系统疾病的1~10岁儿童作为研究对象。100名年龄和性别匹配的健康儿童作为对照。采用火焰原子吸收光谱法检测血铅含量。结果：神经系统疾病组儿童的平均血铅含量显著高于对照组,差异有显著性 (113.2±47.5 μg/L vs 84.7±38.0 μg/L; P<0.01)。神经系统疾病组和对照组分别有44%和19%的儿童血铅超标（>100 μg/L）。结论：儿童血铅水平增高可能与神经系统疾病有关。建议对患神经系统疾病的儿童常规作血铅测定。［中国当代儿科杂志,2009,11（11）：873-876］     

Relationship Between Low-Level Lead Exposure and Neurobehaviors of Preschool Children

目的　探讨低水平铅暴露对儿童神经行为的影响。方法　整群随机抽取某市幼儿园 4～ 6岁 2 11名儿童为研究对象 ,采指端末梢血 2 0 μl,原子吸收石墨炉法测定血铅 ,以血铅水平 10 0 μg/L为界 ,分为高血铅组(≥ 10 0 μg/L)和低血铅组 (<10 0 μg/L) ,采用Achenbach儿童行为量表 (CBCL)及自拟调查表进行问卷调查 ,其结果运用t ,χ2 检验 ,简相关及多元逐步回归等方法进行统计分析。结果　高血铅组外向行为得分及行为异常率(13.2 8± 6 .2 6 ,18.2 6 % )显著高于低血铅组 (9.98± 5 .4 6 ,7.2 9% ) (t =4 .0 6 77,χ2 =5 .4 70 ,均P <0 .0 5 ) ,血铅值与外向行为中多动、攻击、违纪因子分显著正相关 (r =0 .316 4 ,0 .2 82 8,0 .1886 ,P <0 .0 5 ) ,血铅值≥ 15 0 μg/L时 ,行为异常率显著增加 (χ2 =13.6 95 ,P <0 .0 5 )。结论　低水平铅暴露对儿童外向行为具有负性影响。     

Environmental lead exposure during early childhood

OBJECTIVE: To determine the relative contribution of residential lead hazards to children's blood lead concentrations during early childhood. METHODS: We enrolled children 6 months of age and followed them until 24 months of age. Blood and samples of dust, soil, water and paint were analyzed for lead at 6-month intervals, and interviews were conducted to estimate nutritional, behavioral, and demographic factors linked with lead exposure. RESULTS: Of the 276 children enrolled, 249 (90%) were followed until 24 months of age. The geometric mean blood lead concentration of children at 6 months of age was 2.9 microg/dL (95% CI, 2.7-3.1). At 24 months of age, children's mean blood lead was 7.5 microg/dL; 82 (33%) had a blood lead level of > or = 10 microg/dL. In adjusted analyses, lead-contaminated floor dust, soil, and water contributed to children's lead intake throughout the first 2 years of life (P < .05). Lead-contaminated dust from window troughs was a source of lead exposure, especially in the second year of life. Dietary iron intake, but not calcium intake, was inversely associated with blood lead levels (P < .05). Blood lead concentration was over 50% higher in black than in white children (P = .0001). CONCLUSION: Lead-contaminated house dust is the major source of lead intake during early childhood. Black children remain at increased risk for higher blood lead concentration after adjusting for environmental lead exposures and dietary intake.     

A videotape to improve parental knowledge of lead poisoning.

BACKGROUND: Disadvantaged children are at high risk for lead poisoning. Their parents often have poor knowledge of lead poisoning and do not know how to prevent lead poisoning in their child. OBJECTIVE: To assess an educational videotape's impact on parental knowledge and behavior about lead poisoning. DESIGN: Prospective study by self-administered parental survey immediately before (pretest) and after (posttest 1) well visits and mailed 2-4 weeks later (posttest 2). The intervention group watched the videotape immediately after the pretest. SETTING: Pediatric clinic in tertiary care hospital. PARTICIPANTS: Consecutive sample of parents of 6-month-old to 6-year-old children (n = 146). MAIN OUTCOME MEASURES: Survey included demographic questions, the shortened Chicago Lead Knowledge Test (sCLKT), and questions about parental behaviors. RESULTS: Mean pretest scores were 5.8 (SD, 2.8) and 5.3 (SD, 2.2), posttest 1 scores were 6.0 (SD, 2.6) and 10.6 (SD, 2.1), and posttest 2 scores were 6.1 (SD, 2.8) and 9.5 (SD, 2.8) of 14 in the control and intervention groups, respectively. Control and intervention group posttest 1 and posttest 2 score differences were statistically significant (P <.05). Intervention group parents reported more frequent washing of their child's hands (P <.05) and windows, walls, or floors at study completion (P <.05). CONCLUSIONS: The videotape significantly increased sCLKT scores and behaviors that may decrease children's risk of developing lead poisoning. Improvement persisted throughout the study period.     

Maternal perceptions of lead poisoning in children with normal and elevated lead levels.

INTRODUCTION: The purpose of this study was to examine mothers' perceptions of the severity and susceptibility of their children to lead poisoning and to determine if a correlation existed between mothers' knowledge of lead poisoning and their children's blood lead levels. It was thought that mothers of children with lead poisoning (lead levels > or = 10 micrograms/dL) would score lower on a test of their perceptions and knowledge of lead poisoning than would mothers of children with normal lead levels (lead levels < or = 9 micrograms/dL). METHOD: A cross-sectional study comparing scores of a questionnaire completed by mothers whose children had elevated blood lead levels and mothers whose children had normal blood lead levels was conducted. RESULTS: No difference was found in the median test score between the 2 groups. For the correct responses on a question-by-question comparison, significant difference existed between groups; however, the percentage of correct responses was not always greater for the mothers of children with normal blood lead levels. DISCUSSION: Mothers' perceptions and knowledge of lead poisoning were not associated with their children's blood lead levels.     

Parental perceptions of barriers to blood lead testing.

INTRODUCTION: This study identified barriers to blood lead testing from the perspective of parents of young children eligible for Medicaid. METHOD: Data were gathered from three focus groups. Participants were asked if they were familiar with the dangers of high blood lead levels, rationale for not having a child tested for blood lead, what would facilitate having blood lead testing, and how they wanted to learn about blood lead poisoning. RESULTS: Most parents (n=30) were unfamiliar with the causes and effects of lead poisoning. While many reported their child had been tested for lead, others were unsure because they were not told the purpose of blood draws. Participants suggested that having all services in one facility would decrease travel and thus facilitate blood lead testing; others wanted the discomfort associated with phlebotomy minimized. Participants preferred to learn about lead poisoning from low-literacy brochures, videos, and television ads. DISCUSSION: Nurses should institute measures in their practice sites to improve blood lead poisoning prevention education and blood lead testing rates and to reduce the pain and anxiety associated with this procedure.     

Severe lead poisoning in pregnancy.

BACKGROUND: Lead freely crosses the placenta. Consequently, gestational lead poisoning is not only harmful to the woman but also to the developing fetus, invariably producing congenital lead poisoning. The scope and consequences of severe lead poisoning in pregnancy (blood lead level > or =45 microg/dL) have not been well characterized. METHODS: We reviewed our experience in the management of women with severe gestational lead poisoning. Additionally, we reviewed the literature on this disorder in an effort to identify patterns in etiology and outcome. RESULTS: Over a 3-year period treatment was provided to 7 severely lead-poisoned women. A 25-year review of the medical literature identified an additional 8 cases. Among these 15 women, 70% were Hispanic, all of whom developed lead poisoning from the ingestion of soil, clay, or pottery ("tierra"). Other sources of lead poisoning were paint chip ingestion (n = 2), household renovation, and use of a complementary-alternative medication (bone meal). Lead poisoning was discovered in the third trimester in 12 (86%) subjects after the women presented with subtle but characteristic findings of severe lead poisoning, including malaise, anemia, or basophilic stippling on blood smear; one woman was identified when she presented after a generalized seizure, having a blood lead level of 104 microg/dL. Five women received chelation therapy during pregnancy with CaNa(2) EDTA, dimercaprol, or succimer. At delivery mean maternal blood lead level was 55 microg/dL, whereas mean neonatal lead level was 74 microg/dL (P =.009). Thirteen neonates underwent chelation, all within the first 28 days of life. No infant in the current series had an identifiable birth defect. CONCLUSIONS: On the basis of this experience we conclude that severe lead poisoning in pregnant women has the following characteristics: 1) it most often occurs because of intentional pica, 2) its presenting features are subtle, often consisting only of malaise and anemia, and 3) blood lead levels in the neonate are higher than simultaneous maternal lead levels.     

Blood lead levels of maternal-cord pairs, children and adults who live in a central urban area in Turkey

Lead levels were measured in blood samples of 99 adults, 180 children and 143 pregnant women living in Eski?ehir, an urban area in Turkey. One hundred and twenty 120 cord blood and 93 breast-milk samples were also obtained. Mean lead level in blood of adults, children, pregnants, cord blood and in breast-milk samples were 3.13 +/- 1.4 microg/dl, 3.56 +/- 1.7 microg/dl, 2.8 +/- 1.5 microg/dl, 1.65 +/- 1.4 microg/dl and 2.34 +/- 1 microg/L, respectively. It was higher in men than in women in adults (p<0.05) and in iron-deficient children than in those not deficient (p<0.01), and was negatively correlated with body weight (BW) and hemoglobin (Hb) in children (p<0.05 for both). Maternal lead level was strongly related with cord blood and breast-milk lead contents (p<0.001, p<0.0001, respectively). The lead exposure in this region is much lower than the critical level defined for lead poisoning as >10 microg/dl by the Centers for Disease Control and Prevention iron deficiency poor nutrition are the risk factors to lead exposure in children.     

Iron deficiency in young Lebanese children: association with elevated blood lead levels

OBJECTIVE: To measure the prevalence of transferrin saturation (TS) <12%, and iron-deficiency anemia (IDA) in Lebanese children, and their association with dietary habits, sociodemographic characteristics, and blood lead levels. PROCEDURE: A cross-sectional study was performed over a period of 2 years. Of 268 children studied, 142 (53%) were boys and 126 (47%) were girls with an age range of 11 to 75 months. Information collected included nutritional status, blood counts, TS, and blood lead levels. RESULTS: The total prevalence of TS<12% and IDA were 33.6% and 20.5%, respectively, and were associated with not having received iron supplements. IDA was more prevalent among males (P=0.04). TS<12% and IDA were significantly associated with elevated blood lead levels in the first age group (11 to 23 mo) (P=0.04, odds ratio=3.19) and (P=0.006, odds ratio=4.59), respectively. CONCLUSIONS: IDA is common in Lebanese children and is associated with increased blood lead levels, lack of iron supplementation, and cultural dietary habits. Remedial measures such as iron fortification of commonly consumed food are needed on the national level. Lead exposure must be controlled and awareness must be raised about the potentially devastating consequences of combined iron deficiency and lead poisoning on young children.     

Should we screen for lead poisoning after 36 months of age? Experience in the inner city.

INTRODUCTION: Current lead screening guidelines recommend monitoring lead levels in children under 3 years of age. There are, however, a number of children between the ages of 3 and 6 years who have elevated blood lead levels. Whether these lead elevations are new or chronic has not been examined. OBJECTIVE: To determine the proportion of children with lead levels greater than or equal to 10 microg/dL after their third birthday when all prior testing had been normal. METHODS: Retrospective study based on 39000 venous lead tests obtained between 1993 and 1998. From this group, 2046 children were located who had blood lead levels of less than 10 microg/dL before 36 months and who had a follow-up lead level after 36 months. All lead assays were done by the City of New York laboratories, which had an intrasample variability of 13%. RESULTS: Sixty-six (3.2%) of the 2046 children showed an elevation in blood lead for the first time after their third birthday. The abnormal values ranged from 10 to 25 microg/dL. The majority (72%) of the screen-positive children, however, had lead levels of 10 to 12 microg/dL, and 63.3% of screen-positive children with repeat tests had lead levels that reverted to below 10 microg/dL. CONCLUSIONS: The data indicate that some new cases of lead level elevations did occur after 3 years of age in this 'high-risk' community; however, the current study provides evidence that universal screening for lead poisoning beyond 3 years of age is not warranted in this community as it is not likely to pick up clinically important exposure.     

Prevention of lead toxicity in US children.

During the past 2 decades, the proportion of US children who have blood lead concentrations of 10 microg/dL or higher declined by over 80% after the elimination of leaded gasoline and lead solder from canned foods, and a ban on leaded paint used in housing and other consumer products. Fatalities and symptomatic lead poisoning are now rare. Residential lead hazards, which are exceedingly difficult to control, are currently the major source of lead intake for children. Undue lead exposure has retreated into 2 major risk groups; impoverished children who live in older, poorly maintained rental housing and more affluent children who live in older housing undergoing renovation. Despite the dramatic decline in children's blood lead levels, lead toxicity remains epidemic among impoverished children who live in older rental housing, especially those who live in the northeastern and midwestern regions of the United States. There are increasing data linking lead exposure with other systemic effects including delinquency, dental caries, and learning problems. Moreover, there is evidence indicating that there is no discernible threshold for lead-associated cognitive deficits. Thus, it is increasingly important to shift our efforts toward the primary prevention of childhood lead exposure from residential hazards. This article reviews the epidemiology and control of childhood lead exposure, focusing especially on steps necessary to shift toward primary prevention.     

Interpreting and managing blood lead levels of less than 10 microg/dL in children and reducing childhood exposure to lead: recommendations of the Centers for Disease Control and Prevention Advisory Committee on Childhood Lead Poisoning Prevention

Lead is a common environmental contaminant. Lead exposure is a preventable risk that exists in all areas of the United States. In children, lead is associated with impaired cognitive, motor, behavioral, and physical abilities. In 1991, the Centers for Disease Control and Prevention defined the blood lead level that should prompt public health actions as 10 microg/dL. Concurrently, the Centers for Disease Control and Prevention also recognized that a blood lead level of 10 microg/dL did not define a threshold for the harmful effects of lead. Research conducted since 1991 has strengthened the evidence that children's physical and mental development can be affected at blood lead levels of < 10 microg/dL. In this report we provide information to help clinicians understand blood lead levels < 10 microg/dL, identify gaps in knowledge concerning lead levels in this range, and outline strategies to reduce childhood exposures to lead. We also summarize scientific data relevant to counseling, blood lead screening, and lead-exposure risk assessment. To aid in the interpretation of blood lead levels, clinicians should understand the laboratory error range for blood lead values and, if possible, select a laboratory that achieves routine performance within +/-2 microg/dL. Clinicians should obtain an environmental history on all children they examine, provide families with lead-prevention counseling, and follow blood lead screening recommendations established for their areas. As circumstances permit, clinicians should consider referral to developmental programs for children at high risk for exposure to lead and more frequent rescreening of children with blood lead levels approaching 10 microg/dL. In addition, clinicians should direct parents to agencies and sources of information that will help them establish a lead-safe environment for their children. For these preventive strategies to succeed, partnerships between health care providers, families, and local public health and housing programs should be strengthened.