重金属的环境化学行为与毒理学研究

施用污泥及污水灌溉是造成土壤重金属污染的重要原因之一。随灌溉水进入土壤的重金属被吸附、固定在耕作层中，对土壤以及植物的生理性化和生长发育产生不良影响。因此应对重金属污染予以治理。     

施用城市污泥对土壤中重金属积累和迁移的影响

目的 了解城市污泥农用后土壤重金属的积累和迁移。方法 于1998年分不同季节，从苏州、无锡、常州3个城市污水处理厂采集污泥样本，用原子吸收光谱仪分析样本中重金属(Pb、Zn、Cu、Cd、Hg、As)含量和不同形态含量，分析污泥农用后土壤重金属积累及迁移特性。结果 城市污泥重金属含量远高于土壤背景值，3城市污泥中Zn含量均超标，分别达到1199，00、784．00、1216．00mg／kg。长期施用能导致土壤重金属积累。污泥中重金属具有一定的活性和潜在迁移性。结论 城市污泥农用可能会导致土壤和生物体重金属积累，存在着一定的环境重金属积累风险。     

太原市污水厂生活污水污泥性质的调查

城市污水污泥的大量堆积已成为污染城市环境的一个潜在隐患.由于生活污水污泥中含有很高的P、N等植物营养成份,不少国家将其用于农田、园林或绿地,以消除污染,化害为利.太原市污水厂的生活污泥产量较大、占污水污泥总量的70%左右.为了正确合理的施用生活污水污泥,探明污泥的化学组成及其有关性质十分必要.本文针对这些问题对太原市的生活污泥进行了详细的调查研究.1 生活污水污泥的基本化学组成全市以处理生活污水为主的污水厂有杨家堡、北郊、殷家堡、镇城底、古交5个.这些污水厂日处理污水13万t,日产污泥     

城市污泥中邻苯二甲酸酯类环境激素的研究进展

邻苯二甲酸酯类环境激素对环境的污染及对内分泌的干扰作用已引起世界各国的广泛关注.该文论述了城市污泥中邻苯二甲酸酯的研究进展,并针对目前存在的问题,提出了防治措施及研究重点.     

邻苯二甲酸酯类环境污染物健康危害研究新进展

邻苯二甲酸酯类作为塑料添加剂已有将近80年的历史,它们普遍存在于大气飘尘、工业废水、河流、土壤以及固体废弃物中,并已在食品、饮用水、人体体液中被检出,是一种全球最普遍的环境激素类污染物.笔者针对近年来动物实验及人群研究的新进展,综述了邻苯二甲酸酯类对生殖系统和肝脏所造成的毒性,同时,特别关注了邻苯二甲酸酯类主要的体内代谢物邻苯二甲酸单酯对动物和人体的短期、快速作用和长期累积作用,为进一步认识邻苯二甲酸酯类对人类和动物的影响提供了重要参考.     

土壤对污水有机致突物的净化作用

污灌引起土壤污染,但土壤微生物对有机污染物有一定的降解作用,本文报告土壤对进入其中的有机致突物的降解以及色谱/质谱联机的测定结果。 一、材料与方法 1.样品采集和处理:污水、地下水取自北京东郊高碑店污水处理厂和污水灌溉区。经XAD-2树脂柱吸附后,依次以30％丙酮-     

环境中邻苯二甲酸酯类化合物降解技术研究进展

邻苯二甲酸酯类(PAEs)是重要的工业原材料,用于多种合成工艺中,但其能产生类似雌激素样作用,对人类健康和环境造成严重危害,因而研究PAEs降解技术,控制其在环境中的污染浓度具有非常重要的意义。该文综述了近年来PAEs降解技术的进展情况,详细讨论和比较了生物降解、物理吸附、高级氧化技术的优缺点,并指出光催化氧化技术是今后邻苯二甲酸酯降解的发展趋势。     

城市污水厂生化污泥调理脱水研究

通过对调理后生化污泥含水率的测定试验,考察了生石灰、三氯化铁、粉煤灰和煤粉等4种调理剂对污水处理厂生化污泥脱水性能的影响。结果表明:生石灰和三氯化铁对污水的脱水效果较好,且最经济投加量分别为4、2g/100mL,在该条件下,相对于原污泥,抽滤后调理污泥含水率分别降低7.07%和15.22%。     

土壤重金属污染

污染土壤的重金属主要包括汞、镐、铅、铬和类金属砷等生物毒性显著的元素,以及有一定毒性的锌、铜、镍等元素,主要来自农药、废水、污泥和大气沉降等.过量重金属可引起植物生理功能紊乱、营养失调.重金属污染物在土壤中移动性很小,不易随水淋滤,不被微生物降解,通过食物链进入人体后,潜在危害极大.     

城市污水处理厂污泥处理现状及发展分析

污水处理产生的污泥中含有不同的有机和无机污染物，其处置以减量化、稳定化和无害化为目的，经浓缩和脱水后，视不同情况采用焚烧、填埋和资源化等处理技术。本文分析了我国城市污泥处理现状及存在问题，并借鉴国外污水处理厂污泥处理的发展及新技术，提出我国污水处理厂污泥处理的发展方向。     

避孕套的使用与艾滋病的预防

在世界各国育龄夫妇中, 避孕套的使用率差别很大, 少则在1% 以下, 多则高达50% 。中国处于偏下水平, 全国总的避孕套使用率约在3% 左右。全国各省(市) 之间, 避孕套使用率差别很大, 高则达20.12% (天津), 低者仅0.70%(广西)。总的来说, 中国目前避孕套年销售量约为8亿只左右, 年实际生产能力约为10 亿只左右     

Absorption, transport and distribution of vitamin E

Vitamin E is the term used for eight naturally occurring fat-soluble nutrients called tocopherols. alpha-Tocopherol is essential, has the highest biological activity and predominates in many species. In humans vitamin E is the most important lipid soluble antioxidant and deficiency may cause neurological dysfunction, myopathies and diminished erythrocyte life span. alpha-Tocopherol is absorbed via the lymphatic pathway and transported in association with chylomicrons. In plasma, alpha-tocopherol is found in all lipoprotein fractions but mostly is associated with apo B-containing lipoproteins. alpha-Tocopherol is associated with very-low-density lipoprotein when it is secreted from the liver. In the rat, about 90% of total body mass of alpha-tocopherol is recovered in the liver, skeletal muscle and adipose tissue. Most alpha-tocopherol is located in the mitochondrial fractions and in the endoplasmic reticulum, whereas little is found in cytosol and peroxisomes. New clinical evidence from heavy drinkers and from experimental work in rats suggests that alcohol may increase oxidation of alpha-tocopherol. Increased demand for vitamin E has also been observed in premature infants and patients with malabsorption, but there is little evidence that the healthy population requires supplementation of vitamin E to a well-balanced diet.     

广东省1991年IMR U5MR MMR及死因的流行病学调查

为全面掌握婴儿、5岁以下儿童和孕产妇死亡率的水平分布规律,广东省开展了有20个市、78个县参加的覆盖全省人口总数15.5％的大规模回顾性流行病学调查。共收集168728名活产儿,全省平均婴儿死亡率为32.01‰;5岁以下儿童死亡率为41.10‰;孕产妇死亡率为88.31/10万。地区性分布规律分析显示:城市各项死亡率均低于农村;各项死亡率的高低与地理、经济条件有关。两个系统管理率与各项死亡率之间呈负相关。死因构成分析表明:城市与农村的婴儿前三位死因相同,但位次有别;5岁以下儿童死因,城市主要是先天性疾病,农村则以意外及感染性疾病为主;孕产妇死因以产科因素为主,农村第一位死因则为妊娠合并心脏病。     

护士长在形象管理中的作用

为探讨护士长在特色管理中的作用，本阐述了护士长在护理管理中要注重形象管理及特色管理，做到工作热情，技能全面；管理创新，连创佳绩；善于团结，知人善任；全面管理，主动工作。     

浙江省0～4岁儿童生存水平的研究

浙江省１７市、县０～４岁儿童连续２年死亡监测，结果：新生儿、婴儿、０～４岁儿童的平均死亡率分别为１５．４０‰、２１．７１‰、２７．３４‰。死亡儿童的年龄主要集中在新生儿期。儿童的主要死因，新生儿组主要为早产和出生窒息，婴儿组为肺炎，１～４岁组为溺水。１９９２年死于感染性疾病的儿童占死亡儿童总数的３５．８０％，１９９３年占２９．２０％，１９９２年城市儿童死于家中的占总死亡数的３５．７０％，农村占４０．２０％，１９９３年前者占４７．５０％，后者占４９．００％。在农村有超过１／４的儿童死前未得到任何医疗保健服务。提示今后儿童保健工作的重点在农村，重点防治疾病为早产、出生窒息、肺炎和溺水，因此重点保健对象为围产儿和新生儿。     

A major gene controlling warfarin-resistance in the house mouse.

The spread of a "cream" mutant in a wild population of house mice is reported. The hypothesis that the gene responsible for the colour, extreme chinchilla, ce, has spread because of linkage with a major gene for warfarin-resistance, is tested by a linkage backcross. The results prove that a major gene does exist, that it is very closely linked with frizzy, fr, in chromosome 7, which in turn is linked with ce, that it is fully dominant in females at 4 months of age, and that its partial dominance in males is under the control of modifiers. The symbol War is proposed for the gene. Its position in chromosome 7 is analagous with the position of the resistant gene, Rw2, in the rat in the analagous chromosome. The adaptive significance of the finding is discussed, as also are reports of certain other mutants in wild populations of mice.     

辽宁省小型兽类的寄生蚤类研究

于辽宁省小型兽类体外及其窝巢中共发现蚤类５科２０属３３种。蚤种分布与小型兽类的分布密切相关，同时受生态地理条件的影响和制约，即不同地区因宿主分布上的不同，蚤的种类分布有所差异，或同一宿主在不同生态地理区域内，其寄生蚤种类组成也有差异。家鼠优势种为褐家鼠，其寄生蚤共５种，多数地区优势种为不等单蚤，其次为印鼠客蚤。野鼠优势种为黑线仓鼠、黑线姬鼠、达乌尔黄鼠，黑线仓鼠寄生蚤共７种，多数地区优势种为二齿新蚤，其次为短跗鬃眼蚤；黑线姬鼠寄生蚤共５种，多数地区优势种为二齿新蚤，其次为同源栉眼蚤：达乌尔黄鼠寄生蚤共１１种，各地区优势种均为方形黄鼠蚤松江亚种，其次为二齿新蚤。     

Malabsorption in Africa

The most spectacular cases of malabsorption in Africa are those often presenting with gross malnutrition and are due to chronic calcific pancreatitis, ileo-caecal tuberculosis, and small-intestinal trauma or resection. Subchnical malabsorption of carbohydrate is numerically a much greater problem. That is usually associated with systemic infection and is not directly related to marginal malnutrition, or an abnormal jejunal mucosa (tropical enteropathy). The evidence that malnutrition produces significant malabsorption is limited to severe cases of kwashiorkor in children. Megaloblastic anaemia due to dietary folate depletion is often associated with an abnormal D-xylose absorption test and the degree of impairment has been shown to correlate with the severity of the anaemia. Intestinal parasites—Strongyloides stercoralis and Giardia lamblia—are occasional causes of malabsorption.Adult hypolactasia is extremely common in African subjects. Although that does not seem to be responsible for significant ill-health in adults, a low lactase concentration is probably important in the pathogenesis of marasmus in infants. Secondary disaccharidase deficiency is an uncommon finding.The evidence for the existence of tropical sprue in Africa has been reviewed. It is rare in Europeans, compared with the high frequency in Asia. There is now some evidence for the existence of chronic tropical sprue in indigenous Africans but that also seems to be less common and is not as florid as it is in Asian people in Asia. The reasons for those differences in incidence rates have been discussed.All causes of malabsorption common to non-tropical areas must be excluded in the individual patient. Of the overt clinical causes in Africa, ileo-caecal tuberculosis is the most difficult to diagnose.     

Obesity and metabolic disease: is adipose tissue the culprit?

Obesity is a risk factor for the development of type 2 diabetes and CVD. Is adipose tissue the culprit in the relationship between obesity and metabolic disease? It is certainly possible to argue that adipose tissue function is disturbed in obesity in such a way that adverse consequences may follow. For instance, lipolysis is down regulated, the sensitivity of lipolysis to insulin is reduced and there are disturbances in the regulation of adipose tissue blood flow. However, when examined critically these changes can be seen as adaptations to the increased adipose tissue mass, making the situation better rather than worse. In terms of the many peptide and other factors now known to be secreted from adipose tissue, it is easier to argue that adipose tissue is the culprit. However, for no single 'adipokine' is there as yet unequivocal evidence of a link between adipose tissue secretion and adverse metabolic events in other tissues. The best documented of these adipokines in relation to insulin resistance is adiponectin. Here, unusually, adiponectin confers insulin sensitivity, and its secretion is down regulated in obesity. It could be again that adipose tissue has down regulated its function in an attempt to compensate for its increased mass, although certainly that down-regulation is too extreme. On balance, it is clear that adipose tissue is a link in the chain of events leading to metabolic disease, but in many respects it is an innocent intermediary trying to deal with the consequences of positive energy balance, the real culprit.     

Medical abortion and the availability of RU486 -- are women's rights being ignored in developing countries?

Unsafe induced abortion is the leading cause of death in womenaged 15 to 39 in Latin America and a major cause of maternalmortality throughout the developing world. A medical alternativeto early surgical abortion has been developed which could contributeto a reduction in mortality, but which is so far available onlyin France (1988) and Britain (1991). The method is described,with advantages and disadvantages for use in developing countries. The reason for the pharmaceutical company's reluctance to applyfor product licences in other countries is not primarily legal,three-quarters of the women of the world living in countrieswhere abortion is allowed. Nor is it medical, the method havingbeen tested in clinical trials in 20 countries and used by 70000 women in France. The unusual problem is religious. The companywhich owns the worldwide patent faces threats from anti-abortiongroups, particularly in the US, to their other more profitableproducts. US government policy is to withdraw funds from overseasabortion aid even in countries where abortion is legal, denyingwomen in developing countries the choice available to womenin the US. The role of WHO is crucial in providing access tomedical abortion to women in the developing world.