妊娠晚期邻苯基苯酚暴露与新生儿体格指标的关系

目的 探讨孕妇妊娠晚期尿中邻苯基苯酚(o-phenylphenol,OPP)水平与新生儿出生体格指标之间联系。方法 选取某县1 100对孕妇-新生儿,采集孕妇分娩前尿样并完成调查问卷,测定尿中OPP浓度,结合新生儿体格指标进行统计分析。结果 孕妇尿中OPP的检出率为100%,中位值为0.35 μg/L,肌酐校正后中位值为0.54 μg/g,暴露水平稍高于国外类似研究报道。广义线性模型分析显示,孕妇尿中OPP肌酐校正浓度对数可能与新生儿出生身长(β=-0.670,P=0.006)及头围(β=-0.505,P=0.001)呈一定的负相关。按新生儿性别分层后,OPP水平可能与男童身长、体重及头围呈一定程度的负相关(P<0.05),而女童则未发现任何相关。结论 该地区孕妇普遍暴露于OPP,其妊娠晚期OPP水平可能与男性新生儿出生身长、体重及头围呈一定负相关。     

宫内五氯苯酚暴露与1岁婴儿生长发育的关系

目的基于某县孕妇孕晚期尿中五氯苯酚(pentachlorophenol,PCP)暴露负荷,探究PCP暴露与一岁婴儿生长发育的关系。方法选取江苏省某县参加"宫内环境化学物暴露对婴幼儿生长发育影响"队列的母亲及随访的522名婴儿作为研究对象,于1岁时测量婴儿体重、身长等体格发育指标,并采用"0~6岁儿童发育筛查测验"量表评估儿童神经发育状况。以气相色谱-串联质谱法检测孕妇尿中PCP浓度,广义线性模型分析PCP暴露与儿童生长发育指标的关联性。结果孕妇尿中均可检出PCP,宫内PCP暴露与体格指标未见显著性关联;与婴儿神经发育呈显著性负相关(P0.05)。肌酐校正PCP浓度每上升10倍,婴儿的智力指数将降低5.20(95%可信区间:-9.97~-0.43)。有31名和18名婴儿分别表现为神经发育和智力发育异常。经性别分层后,宫内PCP暴露与男婴智力指数呈负相关,与女婴运动能区评分呈负相关。结论该地区孕妇普遍暴露于PCP,孕期PCP暴露可能对婴幼儿神经发育造成危害,潜在的毒理学机制以及安全剂量的制定有待进一步研究。     

孕早期母体尿铬与新生儿出生指标相关性

目的探讨孕妇孕早期尿铬水平与新生儿出生指标的关联性。方法于2018年6—10月选取佛山市某区妇幼保健院154名孕妇为研究对象,收集孕20周前尿液,采用电感耦合等离子体质谱法测定尿铬水平,并根据其浓度三分位数将孕妇分为尿铬低、中和高暴露组,分娩时记录新生儿出生体重、出生身长、出生头围和出生胸围等出生指标,分析母体尿铬水平与新生儿出生指标的关联。结果孕妇孕早期尿铬均数为1.58μg/g肌酐(范围:0.42～4.83μg/g cr),尿铬与新生儿出生体重(r=-0.173,P0.05)、头围均呈负相关(r=-0.170,P0.05)。将新生儿按性别分层后,发现孕妇孕早期尿铬与女性新生儿出生体重(r=-0.299,P0.05)和出生头围(r=-0.253,P0.05)也均呈负相关,未发现孕妇孕早期尿铬与男性新生儿出生指标的相关性。logistic回归显示,在排除混杂因素影响后,孕妇孕早期尿铬水平是新生儿出生体重(OR=0.584,95%CI:0.359～0.952)和出生胸围(OR=0.618 95%CI:0.389～0.983)减少的危险因素(P0.05)。结论本次调查的孕妇孕早期尿铬水平相对较高,孕早期尿铬与新生儿出生体重相关,且这种关联在女性新生儿中更加明显。孕早期尿铬可能与出生头围和出生胸围有关,有待今后进一步进行探究。     

砷暴露人群尿中7-甲基鸟苷与砷的相关性研究

目的探讨广西南丹地区环境砷暴露居民尿7-甲基鸟苷(7-MG)与尿砷的关系。方法于2014年3月应用多阶段分层抽样方法在南丹长老乡抽取122名6~65岁居民,应用电感耦合等离子体质谱法(ICP-MS)检测尿液中的砷含量,用ELISA法测定尿液中7-MG含量。通过广义线性模型分析砷暴露与尿7-MG的关系。结果长老乡儿童尿7-MG水平(G:10.90μg/g cr)高于成人(G:6.82μg/g cr)(P0.05);Spearman相关分析显示成人及儿童尿7-MG水平与土壤砷、饮水砷、蔬菜砷、粮食砷均无统计学关联(P0.05);调整年龄、性别、BMI及吸烟(或被动吸烟)后,广义线性回归分析显示儿童尿7-MG与尿砷呈正向关联(P0.01);成人尿7-MG主要受吸烟和性别影响,与尿砷无统计学关联。结论本次调查的广西南丹长老乡儿童尿7-MG水平可能是砷暴露的一种相对敏感指标。     

孕早期母体尿铬与新生儿出生指标相关性北大核心

目的探讨孕妇孕早期尿铬水平与新生儿出生指标的关联性。方法于2018年6—10月选取佛山市某区妇幼保健院154名孕妇为研究对象,收集孕20周前尿液,采用电感耦合等离子体质谱法测定尿铬水平,并根据其浓度三分位数将孕妇分为尿铬低、中和高暴露组,分娩时记录新生儿出生体重、出生身长、出生头围和出生胸围等出生指标,分析母体尿铬水平与新生儿出生指标的关联。结果孕妇孕早期尿铬均数为1.58μg/g肌酐(范围:0.42~4.83μg/g cr),尿铬与新生儿出生体重(r=-0.173,P<0.05)、头围均呈负相关(r=-0.170,P<0.05)。将新生儿按性别分层后,发现孕妇孕早期尿铬与女性新生儿出生体重(r=-0.299,P<0.05)和出生头围(r=-0.253,P<0.05)也均呈负相关,未发现孕妇孕早期尿铬与男性新生儿出生指标的相关性。logistic回归显示,在排除混杂因素影响后,孕妇孕早期尿铬水平是新生儿出生体重(OR=0.584,95%CI:0.359~0.952)和出生胸围(OR=0.61895%CI:0.389~0.983)减少的危险因素(P<0.05)。结论本次调查的孕妇孕早期尿铬水平相对较高,孕早期尿铬与新生儿出生体重相关,且这种关联在女性新生儿中更加明显。孕早期尿铬可能与出生头围和出生胸围有关,有待今后进一步进行探究。     

上海市婴幼儿血铅水平与体格发育的关系

目的探讨低水平铅暴露对儿童体格发育的影响。方法在上海市5个区县30所托幼机构,对1969名儿童进行了血铅水平的流行病学调查和体格发育等指标测量,并根据儿童身高、体重、头围和胸围计算其Z标准分,然后与血铅水平进行相关分析和逐步回归分析。结果上海市儿童血铅水平几何均数为0．400μmol／L,≥0．483μmol／L的比例为37．8％,血铅水平的几何均数与儿童身高、体重及头围的Z标准分呈显著的负相关。结论低水平铅暴露对上海市婴幼儿的体格发育可能具有不利影响。     

上海市脐带血汞水平及对新生儿体格生长的影响

目的 调查上海市胎儿期汞暴露水平;分析汞暴露对新生儿体格发育的影响;从而为减少汞暴露,提高人口素质提供参考依据.方法 采用分层整群抽样方法 随机抽取上海市10家有助产资格的医院,调查在2008年10月至2009年10月期间分娩的孕产妇及新生儿,分娩时采集脐带全血进行血汞检测;分析脐带血汞水平与新生儿出生身长、体重及头围的关系.结果 共调查1 652对产妇及新生儿,脐带血汞中位数为1.89μg/L,几何均数为(1.95±1.44)μg/L;脐带血汞水平与婴儿(r=-0.078,P=0.012)及男婴(r=-0.087,P=0.041)的出生身长负相关,与女婴的出生身长、体重及头围无相关性.结论 上海市胎儿期汞暴露水平较低.胎儿期低水平汞暴露可影响新生儿出生身长,并存在性别差异.     

银川市社区老年人尿中铁和砷浓度与血脂异常的关联性

目的 探讨银川市社区老年人尿中铁(Iron, Fe)和砷(Arsenic, As)浓度与血脂异常之间的关联性,为血脂异常防治策略的制定提供科学的环境流行病学证据。方法 选取银川市老年人慢性病队列基线调查人群为研究对象,通过问卷调查收集研究对象一般人口学信息,通过健康体检对研究对象血脂、血压和肝功能等指标进行测定,同时收集调查对象晨尿10 mL。使用电感耦合等离子体质谱仪测定研究对象尿中Fe和As的浓度,并用尿肌酐校正,通过条件logistic回归分析模型分析尿中Fe和As浓度与血脂异常患病率之间的关联。结果 血脂异常组老年人尿中Fe浓度(115.97μg/g肌酐)低于健康对照组(139.11μg/g肌酐),差异有统计学意义(Z=3.405,P<0.001);血脂异常组老年人尿中As浓度(77.25μg/g肌酐)高于健康对照组(67.45μg/g肌酐),差异有统计学意义(Z=-3.269,P=0.001)。多因素logistic回归分析模型结果显示,校正协变量后,尿中Fe浓度与老年人血脂异常存在负相关(OR=0.68,95%CI:0.57～0.82,P<0.001),尿中As...     

广东省某工业区环境铅镉暴露对9～11岁儿童智力影响分析

目的分析广东省某工业区环境铅镉暴露对儿童智力发育的影响,为环境重金属污染的治理提供科学依据。方法选取已被国家环境保护部划入环境重金属污染重点防治区的广东省某工业区所在镇为暴露区,相邻上风侧的镇为对照区。暴露区和对照区调查对象分别为来自所在区域的镇一级小学9~11岁在校学生。采用联合型瑞文智力测验量表中国第二次修订版(CRTC2)对儿童进行智力测验,同时对暴露区和对照区的儿童进行尿铅、尿镉含量检测。结果暴露区儿童尿铅、尿镉含量分别为4.040、1.434μg/L,对照区儿童尿铅、尿镉含量分别为2.136、1.023μg/L,暴露区儿童尿铅、尿镉含量高于对照区儿童(P0.01)。暴露区和对照区儿童IQ值分别为103.38和106.23,暴露区儿童IQ值低于对照区(P0.01)。多因素线性回归分析结果显示,调整其他影响因素后,尿铅对IQ值有负面影响(β=-4.442,P0.05),而尿镉对IQ值的影响无统计学意义(β=-1.277,P0.05)。同时,尿铅、尿镉的交互作用对IQ值的影响也没有统计学意义(P0.05)。结论环境重金属污染已经对儿童智力发育产生负面影响,应加大对环境重金属污染的治理力度,以降低儿童重金属暴露所带来的健康风险。     

环境铅镉联合暴露对儿童智力及神经行为的影响

目的探讨南方某工业区环境铅、镉联合暴露对儿童智力及神经行为的影响。方法选取南方某金属污染重点防治区所在镇为暴露区,相邻上风侧的镇为对照区,按照年龄分层分别抽取暴露区和对照区镇一级小学9~11岁在校学生为调查对象,采用联合型瑞文智力测验量表中国第2次修订版(CRT-C2)对学生进行智力测试,采用天津医科大学编制的津医精神运动成套测验(JPB)对学生进行神经行为测试;同时采用ICP-MS方法检测血铅、血镉含量。结果共调查530名9~11岁在校学生,其中暴露区266人,对照区264人。暴露区儿童血铅、血镉几何均数分别为65.89、1.93μg/L,对照区儿童血铅、血镉几何均数分别为37.21、1.07μg/L,暴露区儿童血铅、血镉水平均高于对照区(均P0.01)。暴露区和对照区儿童IQ值分别为103.38±10.76、106.23±12.84,暴露区儿童IQ值低于对照区(P0.01)。暴露区儿童划消数字、连接数字、目标追踪3个测试项目得分均低于对照区儿童(均P0.01)。多因素线性回归分析结果显示,血铅不仅与IQ值呈负相关(β=-4.16,P0.01),而且与划消数字(β=-0.96,P0.05)、连接数字(β=-1.54,P0.01)、目标追踪(β=-11.85,P0.01)均呈负相关;血镉仅与目标追踪呈负相关(β=-31.21,P0.01)。血铅和血镉的交互作用与IQ值以及5个神经行为测试项目的相关性均无统计学意义(均P0.05)。结论环境铅、镉暴露能分别影响儿童智力和神经系统发育,尚未发现铅、镉联合暴露的影响。     

Public Protection in an Open Exhibit of Radioactivity

Studies on the effects of lead on the somatic growth of children are limited and contradictory. The authors investigated the adverse effects of blood lead concentration on the somatic growth of primary-school-age children. In this study, there was a total of 522 children, aged 6–9 y, who resided in three areas of Greece (i.e., Loutraki, Lavrion, and Elefsina). The medical evaluation included medical history; physical examination; and measurements of height, head circumference, and chest circumference. The authors also evaluated dietary information, socioeconomic status, and height of parents. The authors conducted laboratory tests for hematological parameters and blood lead levels. The mean blood lead level was 12.3 μg/dl (standard deviation = 8.9 μg/dl), and levels ranged from 1.3 μg/dl to 51.2 μg/dl. There were negative monotonic relationships between growth parameters and blood lead levels, even after the authors allowed for confounding effects. An increase in blood lead level of 10 μg/dl was associated with a decrease of (a) 0.33 cm in head circumference (95% confidence interval = 0.12, 0.55; p = .002); (b) 0.86 cm in height (95% confidence interval = 0.14, 1.16; p = .020); and (c) 0.40 cm in chest circumference (95% confidence interval = ?0.22, 1.02; p = .207). These findings led the authors to conclude that a decrease in growth in children may be associated with blood lead concentrations.     

维生素D受体基因Bsm1多态性与铅暴露儿童的血铅、锌原卟啉和体格发育指标的关系

在 476名严重环境铅暴露儿童中 ,研究了维生素D受体基因Bsm1位点多态性对血铅、锌原卟啉、头围、身高和体重等指标的影响。使用协方差分析校正了年龄、性别、父母文化程度和血铅等影响因素后 ,具有B等位基因儿童的头围明显大于bb基因型个体 (P =0 0 2 ) ;分层分析发现在高血铅组和男性组中Bsm1多态性明显影响头围 (P <0 0 5)。未发现Bsm1位点多态性对血铅、锌原卟啉、身高和体重的明显影响。结果表明 ,VDR基因Bsm1位点的遗传变异可修饰严重铅暴露条件下铅对儿童颅骨发育的影响。     

Newborn infant urinary cotinine and birth outcomes in the Jerusalem Environment Mother and Child Cohort Study

BackgroundEnvironmental tobacco smoke (ETS) exposure during pregnancy can cause preterm delivery and childhood cancer. The aim of this study was to measure ETS exposure in pregnant women and in newborn infants in Israel using urinary cotinine measurements, to assess predictors of ETS exposure in these vulnerable groups, and to assess associations with birth effects (birth weight, birth length, head circumference) in newborn infants.MethodsWe analyzed urinary cotinine and creatinine in 265 non-smoking pregnant women and 97 newborns, and analyzed associations with self-reported exposure to ETS, paternal smoking, sociodemographic variables and with birth outcomes (birth weight, birth length, head circumference).Results37.7% of pregnant women and 29.0% of infants had urinary cotinine concentrations above the level of quantification (LOQ) of 1 μg/L, whereas 63.8% and 50.5%, respectively, had urinary cotinine concentrations above the level of detection (LOD) of 0.5 μg/L. Median unadjusted and creatinine adjusted urinary concentrations of cotinine in pregnant women were 0.7 μg/L, and 0.9 μg/g creatinine, respectively, and in newborn infants were 0.5 μg/L, and 1.3 μg/g creatinine, respectively. We did not find an association between maternal and infant urinary cotinine level. Maternal (but not infant) urinary cotinine was significantly associated with paternal smoking (p < 0.05). Infant (but not maternal) cotinine above the LOQ was negatively associated with birth weight (p < 0.05).ConclusionsIn this high socioeconomic cohort, almost a third of newborn infants born to non-smoking mothers had quantifiable levels of urinary cotinine. This is the first study showing that newborns with quantifiable urinary cotinine levels have lower birth weight.     

The Relationships between Sugar-Sweetened Beverage Intake and Cardiometabolic Markers in Young Children

BackgroundThe consumption of sugar-sweetened beverages has been implicated as a major contributor to the development of obesity and cardiometabolic disease.ObjectiveTo evaluate the relationships between sugar-sweetened beverage intake and cardiometabolic markers in young children.DesignA cross-sectional analysis of the National Health and Nutrition Examination Survey data collected by the National Center for Health Statistics.ParticipantsA total of 4,880 individuals aged 3 to 11 years from nationally representative samples of US children participating in the National Health and Nutrition Examination Survey during 1999-2004 were studied.Main outcome measuresConcentrations of total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglyceride, and C-reactive protein as well as waist circumference and body mass index percentile for age–sex.Statistical analyses performedMultivariate linear regression analyses were performed to determine independent associations between each outcome variable and the number of serving equivalents of sugar-sweetened beverages consumed after adjusting for age, sex, race, poverty status, physical activity, and energy intake.ResultsIncreased sugar-sweetened beverage intake was independently associated with increased C-reactive protein concentrations (P=0.003), increased waist circumference (P=0.04), and decreased high-density lipoprotein cholesterol concentrations (P<0.001). Subgroup analyses demonstrated differences in the association of sugar-sweetened beverage intake with metabolic markers and anthropometric measurements among age ranges, sex, and racial/ethnic groups.ConclusionsIn this cross-sectional analysis of children's dietary data, sugar-sweetened beverage intake was independently associated with alterations in lipid profiles, increased markers of inflammation, and increased waist circumference in children. Prospective studies are needed, but awareness of these trends is essential in combating the growing metabolic and cardiovascular disease burden in the pediatric population.     

Maternal serum concentrations of perfluoroalkyl substances and birth size in British boys

Per- and polyfluoroalkyl substances (PFAS) have been widely used in commercial and industrial manufacturing processes since the 1950s. Inverse associations between prenatal exposure to PFAS and birth size have been found in populations around the globe. This study examined the association of prenatal maternal serum concentrations of perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA) and birth size in British boys. The study included 457 mother-son dyads participating in the Avon Longitudinal Study of Parents and Children (ALSPAC). Birth weight (g), crown to heel length (cm), and head circumference (cm) were collected at delivery. PFAS were detected in all maternal serum samples during pregnancy (median: 30 weeks gestation (interquartile range: 12–33)). Median concentrations (interquartile range) were 13.8 ng/mL (11.0, 17.7), 3.0 ng/mL (2.3, 3.8), 1.9 ng/mL (1.4, 2.5), and 0.4 ng/mL (0.3, 0.5) for PFOS, PFOA, PFHxS, and PFNA, respectively. In multivariable linear regression models, inverse associations were detected between PFOS (continuous) and birth weight (β = ?8.50 g, 95% CI = ?15.93, ?1.07 g), crown to heel length (β = ?0.04 cm, 95% CI = ?0.08, ?0.01 cm), and head circumference (β = ?0.02 cm, 95% CI = ?0.04, ?0.002 cm). In conclusion, prenatal exposure to high levels of PFOS may be associated with reduced birth size in male infants.     

Levels of phthalate metabolites in urine among mother-child-pairs - results from the Duisburg birth cohort study, Germany

Phthalates are used ubiquitously and human exposure is widespread. Some phthalates are anti-androgens and have to be regarded as reproductive and developmental toxicants. In the Duisburg birth cohort study we examine the associations between hormonally active environmental agents and child development. Here we report the concentrations of 21 primary and secondary phthalate metabolites from seven low molecular weight (LMW) phthalates (DMP, DEP, BBzP, DiBP, DnBP, DCHP, DnPeP) and five high-molecular weight (HMW) phthalates (DEHP, DiNP, DiDP, DPHP, DnOP) in 208 urine samples from 104 mothers and their school-aged children. Analysis was performed by multidimensional liquid chromatography coupled to tandem mass spectrometry (LC/LC-MS/MS), using internal isotope-labeled standards. In both children and mothers, 18 out of 21 phthalate metabolites were detected above the limits of quantification (between 0.2 and 1.0 μg/l) in nearly all urine samples. Among the LMW phthalates, the excretion level (geometric mean) of the ΣDiBP metabolites was most prominent in children (103.9 μg/l), followed by ΣDnBP (56.5 μg/l), and MEP (39.1 μg/l). In mothers ΣDiBP (66.6 μg/l) was highest, followed by MEP (50.5 μg/l), and ΣDnBP (36.0 μg/l). Among the HMW phthalates, ΣDEHP was highest in children and mothers (55.7/28.9 μg/l). Compared to reference values derived from the German Human Biomonitoring Commission, children's metabolite concentrations were within background levels, whereas for mothers considerably higher exposure to the LMW phthalates DnBP and DiBP, and the HMW phthalate DEHP was detected (MiBP: 10.7%; MnBP: 11.7%; ΣDEHP: 23.3% of the samples were above the reference values). The LMW metabolites from DMP, DiBP, and DnBP, and the HMW metabolites from DEHP and DiNP were correlated between the mothers and children, probably indicating shared exposure in the immediate surrounding environment. Children showed higher excretion levels for most of the secondary metabolites than mothers, confirming previous findings on higher oxidized metabolite levels in children. The LMW metabolites ΣDiBP, ΣDnBP, and MMP, and the HMW metabolites ΣDEHP were negatively associated with children's age. The LMW metabolites ΣDiBP, ΣDnBP, and MBzP were inversely associated with body mass index of the children. The LMW ΣDiBP metabolites revealed a significant association with nicotine metabolites in urine from both children and mothers. Further analyses are ongoing to study long-term phthalate exposure and the associations with puberty outcome in these children.     

基于生物监测的儿童尿中对硝基苯酚暴露评估

目的 基于尿中对硝基酚 (para-nitrophenol,PNP)的生物监测评估儿童体内暴露负荷,为保护儿童健康提供科学依据。方法 选取江苏省某县参加“宫内环境化学物暴露对婴幼儿生长发育影响”队列的母亲于2009 年6 月-2010 年1月期间所产441名3岁幼儿作为研究对象,在其父母协助下完成问卷调查和尿样采集,采用气相色谱-串联质谱法(GC-MS/MS)检测儿童尿中PNP的含量,通过非参数检验和多元线性回归分析可能的影响因素,基于尿样监测数据评估并比较了儿童体内PNP负荷水平。结果 所有研究对象尿中均可检出对PNP,肌酐校正与未校正的PNP几何均值分别为12.14 μg/g cre.和5.08 μg/L。男童与女童PNP暴露水平未见统计学差异;多元线性回归结果显示,采样季节是影响PNP暴露水平的重要因素,夏季暴露水平高于其他季节,差异具有统计学意义(P<0.05),儿童尿中PNP浓度高于国外同类研究。结论 研究地区儿童普遍高暴露于PNP或其前体物质,其对儿童的潜在健康风险不容忽视。     

综合指数法在学龄前儿童生长发育评价中的应用

目的利用综合指数法评价学龄前儿童的生长发育状况,探讨科学的评价方法。方法采用两阶段分层整群抽样,从长沙市幼儿园随机抽取4所,对幼儿园儿童整群抽样进行体格发育测量,获取身高、体重、头围、胸围、腰围、上臂围、小腿围、皮褶厚度等形态学指标,采用综合指数法进行评价。结果各个年龄组间综合指数比较有显著性差异(F=10.813,P=0.0001),经多重比较,3岁组综合指数显著高于4岁组和5岁组(P=0.0001);而性别间无差异;不同级别幼儿园之间比较,省级和市区级幼儿园儿童综合指数差异有显著性(P=0.025);综合指数法与Z评分法两种评价结果经χ2检验,差异有显著性(P=0.0001)。结论综合指数法可以将多个指标的信息综合起来,从整体上评价儿童生长发育状况。     

Impact of lead transport on children's blood and environmental lead levels

Introduction: A lead monitoring project was established in 1996 to monitor the environmental and health effects of lead being transported through a remote town in tarpaulin‐covered trucks. Methods: Dust samples from sites on the transport route were collected at 3–6 monthly intervals between 1996 and 1999. Annual blood lead testing clinics, offering voluntary testing to children, were conducted from 1997 to 1999. Results: Of the 55 dust samples analysed, only nine contained particles of lead concentrate and these were present at very low levels. During the project 167 children were tested. The geometic mean of blood lead levels in 1997, 1998 and 1999 were 4.5 μg/dL, 5.0 μg/dL and 5.1 μg/dL, respectively (all within the normal range). Residence on the transport route was not associated with higher lead levels (P > 0.05). Conclusions: Lead transport was not associated with any detectable environmental contamination or increase in children's blood lead levels.