Umbilical cord blood mercury levels in China

Mercury (Hg) is a well-known neurotoxicant. Hg exposure at high levels can harm individuals of all ages. Even low level exposure to Hg can damage the brain of fetuses and young children, and affect their central nervous system and cognitive development. The aims of our study were to measure total Hg levels in infant umbilical cord blood and to investigate the risk factors associated with total Hg cord blood levels in various cities in China. Our goal was to provide clues for the prevention of Hg exposure in utero. The results indicated that the average cord blood mercury levels (CBMLs) were (1.81 ± 1.93) μg/L, which were lower than those found in most previous studies. The concentrations also differed according to geographic region. The CBMLs were not only associated with family economic and living conditions, but also with diet in pregnant women, especially the intake of marine fish, shellfish, poultry, formula milk and fruits.     

A national survey of polybrominated diphenyl ethers (PBDEs) and indicator polychlorinated biphenyls (PCBs) in Chinese mothers' milk

Seven polybrominated diphenyl ethers (PBDEs) congeners (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154 and BDE-183) and six indicator polychlorinated biphenyls (PCBs) congeners (CB-28, CB-52, CB-101, CB-138, CB-153 and CB-180) were measured in 24 pooled human milk samples comprised of 1237 individual samples from 12 provinces in China. The samples were taken to estimate the background body burden of general population and assess nursing infant exposure via human milk in China. The median concentrations of ∑₇PBDEs and ∑₆PCBs were 1.49 and 10.50 ng g⁻¹ lipid weight (lw), respectively. BDE-28, BDE-47 and BDE-153 were predominant PBDE congeners accounting for nearly 70% of ∑₇PBDEs. As for indicator PCBs, CB-153 was the most abundant congener, followed by CB-138. In our study, there was no significantly statistical relationship between concentrations of PBDEs in milk samples and maternal age as well as dietary habits. ∑₇PBDEs did not correlate to ∑₆PCBs in Chinese mothers’ milk. The human exposure to indicator PCBs in China was found to be significantly determined by maternal age, dietary habits and geographical factors. It is suggested that Chinese general population is probably exposed to PBDEs with multiple sources and pathways. The estimated daily intakes (EDI) of BDE-47, BDE-99 and BDE-153 for the Chinese nursing infant were much lower than corresponding threshold reference values suggested by USEPA.     

湘西沅麻盆地的干旱与对策

笔者以无雨日数、旱期内降水量和干旱对农业生产的影响确定干旱等级指标,分析了沅麻盆地干旱的特征,特别指出当地干旱频率在加快、旱区在扩大。文中的观点可供湘西山区开发,乃至我国东部亚热带丘陵山区开发参考。     

Ecological planning: A review

Beginning with the passage of the National Environmental Policy Act in 1969, the federal government of the United States has enacted numerous pieces of legislation intended to protect or conserve the environment. Other national governments have also enacted environmental legislation during the past two decades. State and local governments have also adopted policies concerned with environmental planning and management. Multiple laws and overlapping governmental agency responsibilities have confused development and resource management efforts. A comprehensive methodology that integrates the legal mandates and the agency missions into a common and unified framework is needed. Ecological planning offers such a method. Application of the method allows planners and resource managers to better understand the nature and character of the land and/or resource and therefore make better decisions about its appropriate use or management. The steps taken in an ecological planning process—1) goal setting, 2) inventory and analysis of data, 3) suitability analysis, 4) developing alternatives, 5) implementation, 6) administration, and 7) evaluation—are outlined and explained. Hand-drawn overlays and computer programs as techniques for handling ecological planning information are compared. Observations and suggestions for further research are offered.     

陕西渭北煤矿区地质灾害浅析

渭北煤矿区是陕西省的重要煤炭生产基地,随着矿区的开发,地质环境日趋恶化,地质灾害亦日渐增多。矿区地质灾害既普遍又严重,主要类型有:地震、活动断裂、滑坡、地面裂陷、泥石流及土壤侵蚀等。其内力型地质灾害主要受新构造运动所控制,而外力型地质灾害多与人类活动有关,即与矿区开发有关。     

核电站事故前人因可靠性分析方法

人因可靠性分析 (HRA)已成为概率安全分析 (PSA)必不可少的内容 ,事故前人因事件可靠性分析对有效预防维修、调校工作中的人因失误有着重要作用 ,是人因可靠性分析的重要组成部分 ,对PSA最终计算结果有重要影响。笔者结合核电站人因可靠性分析的实际需求 ,运用了以THERP为主的人因失误概率评价方法 ,创建了事故前人因事件分析的基本程序、方法及分析文档模式 ,表述了程序化的事故前人因事件分析模式 ,为我国核电站事故前人因可靠性分析提供了完整和有效的分析方法 ,并有效用于秦山核电站的PSA。     

1990～2003年中国民航152起小于间隔飞行事件的分类统计研究

小于间隔飞行事件是双机空中相撞事故的潜在威胁 ,对此类事件进行人的因素的分类统计分析有助于寻找错误原因和规律。笔者以 15 2起小于间隔飞行事件为数据源 ,根据Reason模型和HFACS系统进行分类 ,统计了各个因素所占的百分比和部分因素的相关程度。结果表明 ,小于间隔事件与生物节律的关系并不明显而与交通流量密切相关 ;机组不安全行为与管制员未能有效实施监控职能密切相关 ;决策错误、操作错误和知觉错误的主要表现形式分别为 :混淆指令、调错高度窗、听错指令和记错 /忘记管制员指令以及未理解管制员指令 ;不良的机组资源管理是导致小于间隔最主要的机组因素 ,主要表现形式为机组成员之间的配合不好、未有效实施交互监视和交互检查 ;“高度指令”和“相对活动高度”提示的语序问题是一个值得进一步研究的课题。     

Identification of triploid trophoblast cells in peripheral blood of a woman with a partial hydatidiform molar pregnancy

In a woman with a partial hydatidiform molar pregnancy with 69,XXY karyotype, the presence of male fetal cells of trophoblastic origin was demonstrated in maternal blood by X/Y-chromosome specific PCR and by immunostaining combined with FISH on two cell populations isolated from maternal blood. Blood was obtained three weeks prior to the detection of fetal demise, at 13 weeks' gestation. Results were confirmed on formalin-fixed paraffin-embedded molar tissue, removed at 16 weeks' gestational age for therapeutic reasons. The results indicate that both plasma and cells from maternal peripheral blood might be useful for non-invasive prenatal diagnosis of fetal aneuploidies, as described in the current case with a partial molar pregnancy. Copyright © 2001 John Wiley & Sons, Ltd.     

Toward understanding the human dimensions of the rapidly changing arctic system: insights and approaches from five HARC projects

Human dimensions research focuses on the interrelationships between humans and the environment. To date, human dimensions research in arctic regions has concentrated primarily on local events and contexts. As such, it complements analysis elsewhere of adaptation and sustainable development within broad institutional, social, and environmental contexts. This paper reviews five projects from the Human Dimensions of the Arctic System (HARC) initiative, established by the US National Science Foundation in 1997. Common themes and findings are highlighted: climatic variations or change affect societies through interactions with human activities; population dynamics provide key quantitative indicators of social impacts and well being; and specific impacts and responses are the result of complex, context-sensitive interactions. Congruent approaches to the challenges of interdisciplinary research are also identified: multivariate time plots aid the integration of data, retrospective and prospective studies are part of a continuum and reinforce one another, comparative studies are essential for understanding general principles of human dimensions, and arctic residents can play a vital role in research and action.     

用人淋巴细胞微核试验检测地面水致突变性

用胞质阻断微核试验（CBMN）来检测浙江某地区地面水有机提取物的致突变性,并与Ames试验结果进行了比较。结果表明,该水样中含有微量致突变物,CBMN试验和Ames试验结果基本相符,说明CBMN试验用作检测地面水致突变性是可行的,但灵敏度略低于Ames试验。