320例儿童手指血微量元素结果分析

为对门诊健康体检的320例0～10岁儿童手指血的微量元素及其相关情况进行分析,用原子吸收光谱仪测定了其指血的铜、锌、钙、镁、铁的含量。结果表明,锌缺乏随着年龄的增加逐渐减少,铁、钙缺乏随着年龄的增加而逐渐增多。提示孝感市1个月-10岁的儿童存在一定的微量元素缺乏,应注意均衡饮食,加强锌、铁、钙的补充及吸收。     

韶关市学龄前儿童血铅与身高体质量关系的初步研究

为探讨韶关市学龄前儿童血铅水平及其对儿童身高、体质量的影响，随机抽取1128名2～6岁儿童为调查对象，测定其身高、体质量，并分别换算成z标准分；采指端末梢血20止，用钨舟原子吸收光谱法，测定血铅水平。结果显示，2～6岁1128名儿童均值97．9μg/L，几何均值82．1μg/L，铅中毒率39．89％，血铅水平及铅中毒率，男、女童无显著差异；血铅值与身高呈显著性负相关，随着年龄的增加，其相关系数减少；在6岁前，血铅值与体质量呈显著性负相关；高血铅组（≥100μg／L）女童体质量、身高z分显著低于低血铅组；男童体质量Z分显著低于低血铅组。提示年龄越小，铅暴露对儿童身高、体质量发育的损害越大；其中对女童的影响较明显。     

伦教镇2020名儿童指血微量元素调查分析

测定了伦教镇2020名3～6岁儿童指血中锌、铁、钙、铅四种元素含量,了解其分布情况。结果显示,铁、钙缺乏少见,部分儿童仍有锌缺乏;总体情况,男、女儿童的锌、铁、钙三种微量元素的平均值均处于正常范围,血铅的平均值则偏高。     

深圳市宝安区学龄前儿童发铅水平调查

为了解深圳市宝安区学龄前儿童发铅水平,探讨与其它5种元素的相互关系,对来自宝安光明预防保健所资料完整的482名2~5岁儿童的头发微量元素检测结果进行了分析,发铅及其它元素含量均采用原子吸收分光光度法测定。结果表明,学前儿童发铅均值8.52μg/g,几何均值6.28μg/g,高发铅(≥10μg/g者)检出率为33.4%;随年龄增长,发铅水平水平呈下降趋势,F=1.835,χ2=1.250,P>0.05;外来务工家庭儿童发铅水平和高发铅检出率[258例,(8.86±2.21)μg/g,39.5%]显著高于本地居民家庭儿童[224例,(8.13±2.02)μg/g,26.3%],两者比较,t=3.796,χ2=9.385,P=0.01;工业区儿童发铅水平显著高于居民区儿童(Q=6.363,P<0.01),发铅值与其发铁值显著负相关(r=0.212,P=0.05)。提示预防儿童铅中毒,要特别关注外来务工家庭小年龄儿童的保护。     

A Hybrid Logistic Model for Case-Control Studies

For logistic regression in case-control studies, when risk factors associated with the outcome are exceedingly rare in the control group, the estimation of parameters in the model becomes difficult. In this paper, we propose a two-stage hybrid method to achieve this. In the first stage, we model the risk due to the rare factor, and in the second stage we model the residual risk due to the other factors using standard logistic model.     

Aerodynamic Measurements: Normative Data for Children Ages 6:0 to 10:11 Years

Normative measures of open quotient, speed quotient, maximum flow declination rate (MFDR), and subglottal pressure were determined for 75 children between the ages of 6 years 0 months and 10 years 11 months. The participants produced a sustained /a/ at low, comfort, and high pitches for a minimum of 5 seconds, and five to seven repetitions of /pa/ at low, comfort, and high pitches. No statistically significant differences were found in the mean measures of any aerodynamic variables (open quotient, speed quotient, maximum flow declination rate, subglottal pressure) between the frequency levels (low, comfort, high pitches). Also, no strong evidence (P > .05) exists that age or sex effect differed between the frequency levels (low, comfort, high) for any of the aerodynamic measures. For /a/ response tasks, mean open quotient measures increased slightly from low to comfort frequency and from comfort to high frequency. Mean speed quotient measures showed minimal differences between low and comfort frequency, with decreased mean measures for high frequency. Mean MFDR measures increased from low to comfort frequency and from comfort to high frequency. Mean subglottal pressure measures increased slightly from low to comfort frequency and from comfort to high frequency.     

铅暴露与儿童智力、行为关系的研究

为研究儿童智力，行为与儿童发铅浓度之间的关系，来对自医院儿童心理咨询门诊6－12岁就诊儿童共62名，用中国修订韦氏儿童智力量表进行了智力测验，同时测试了儿童发铅水平，并进行相关分析，为控制其他混杂因子，应用广义线性模型（CLM）分析了发铅对儿童智商的作用，结果表明，发铅与儿童智商呈显著负相关，发铅对儿童智力有害。     

广州市荔湾区555例学龄儿童血液锌原卟啉测定结果分析

对广州市荔湾区555例6-7岁儿童进行了血红蛋白(Hb)、锌原卟琳(ZPP)测定，并对部分儿童进行了血清铁蛋白(SF)及血铅(Pb)测定，以了解本区学龄儿童铁缺乏及铅中毒发病情况。结果显示，隐性缺铁(ID IDE)245例，发病率44．1％，其中缺铁性贫血(IDA)107例，发病率为19．3％，铅中毒发病率为48．6％。提示本区学龄儿童铁缺乏及铅中毒发病率相当高(尤其后者)，应加强防治工作。     

Volatile organic compound emissions from markers used in preschools,schools, and homes

There is little published research examining volatile organic compound (VOC) emissions from art markers. In this study, we characterised VOC emission rates from markers commonly used by children at home and in school, and by teachers in their classrooms. We developed a method to measure standardised emission rates under controlled laboratory conditions, focusing on four major marker types: permanent, dry erase, highlighter, and washable. Emission rates for other less common marker types were also measured. We conducted additional experiments determining changes in emission profiles over short and long time periods (several hours up to daily use over about 2 months), as well as during periods of active drawing. We tested a total of 101 markers and report emission rates for 60 chemicals. Permanent and dry erase markers had average total VOC emissions more than 400 times higher than highlighters and washable markers. Alcohols were the most highly emitted class of VOCs from permanent and dry erase markers. Some chemicals associated with potentially serious health concerns were also identified. Future studies that employ full-scale chamber experiments and personal monitoring in classrooms to measure children’s actual exposures are recommended.